Add options to check certificate types.

[openssl.git] / CHANGES

 OpenSSL CHANGES
 _______________

 Changes between 1.1.0a and 1.1.1 [xx XXX xxxx]

  *) OpenSSL now fails if it receives an unrecognised record type in TLS1.0
     or TLS1.1. Previously this only happened in SSLv3 and TLS1.2. This is to
     prevent issues where no progress is being made and the peer continually
     sends unrecognised record types, using up resources processing them.
     [Matt Caswell]

  *) 'openssl passwd' can now produce SHA256 and SHA512 based output,
     using the algorithm defined in
     https://www.akkadia.org/drepper/SHA-crypt.txt
     [Richard Levitte]

  *) Heartbeat support has been removed; the ABI is changed for now.
     [Richard Levitte, Rich Salz]

  *) Support for SSL_OP_NO_ENCRYPT_THEN_MAC in SSL_CONF_cmd.
     [Emilia Käsper]

 Changes between 1.1.0b and 1.1.0c [xx XXX xxxx]

  *) ChaCha20/Poly1305 heap-buffer-overflow

     TLS connections using *-CHACHA20-POLY1305 ciphersuites are susceptible to
     a DoS attack by corrupting larger payloads. This can result in an OpenSSL
     crash. This issue is not considered to be exploitable beyond a DoS.

     This issue was reported to OpenSSL by Robert Święcki (Google Security Team)
     (CVE-2016-7054)
     [Richard Levitte]

  *) CMS Null dereference

     Applications parsing invalid CMS structures can crash with a NULL pointer
     dereference. This is caused by a bug in the handling of the ASN.1 CHOICE
     type in OpenSSL 1.1.0 which can result in a NULL value being passed to the
     structure callback if an attempt is made to free certain invalid encodings.
     Only CHOICE structures using a callback which do not handle NULL value are
     affected.

     This issue was reported to OpenSSL by Tyler Nighswander of ForAllSecure.
     (CVE-2016-7053)
     [Stephen Henson]

  *) Montgomery multiplication may produce incorrect results

     There is a carry propagating bug in the Broadwell-specific Montgomery
     multiplication procedure that handles input lengths divisible by, but
     longer than 256 bits. Analysis suggests that attacks against RSA, DSA
     and DH private keys are impossible. This is because the subroutine in
     question is not used in operations with the private key itself and an input
     of the attacker's direct choice. Otherwise the bug can manifest itself as
     transient authentication and key negotiation failures or reproducible
     erroneous outcome of public-key operations with specially crafted input.
     Among EC algorithms only Brainpool P-512 curves are affected and one
     presumably can attack ECDH key negotiation. Impact was not analyzed in
     detail, because pre-requisites for attack are considered unlikely. Namely
     multiple clients have to choose the curve in question and the server has to
     share the private key among them, neither of which is default behaviour.
     Even then only clients that chose the curve will be affected.

     This issue was publicly reported as transient failures and was not
     initially recognized as a security issue. Thanks to Richard Morgan for
     providing reproducible case.
     (CVE-2016-7055)
     [Andy Polyakov]

  *) Removed automatic addition of RPATH in shared libraries and executables,
     as this was a remainder from OpenSSL 1.0.x and isn't needed any more.
     [Richard Levitte]

 Changes between 1.1.0a and 1.1.0b [26 Sep 2016]

  *) Fix Use After Free for large message sizes

     The patch applied to address CVE-2016-6307 resulted in an issue where if a
     message larger than approx 16k is received then the underlying buffer to
     store the incoming message is reallocated and moved. Unfortunately a
     dangling pointer to the old location is left which results in an attempt to
     write to the previously freed location. This is likely to result in a
     crash, however it could potentially lead to execution of arbitrary code.

     This issue only affects OpenSSL 1.1.0a.

     This issue was reported to OpenSSL by Robert Święcki.
     (CVE-2016-6309)
     [Matt Caswell]

 Changes between 1.1.0 and 1.1.0a [22 Sep 2016]

  *) OCSP Status Request extension unbounded memory growth

     A malicious client can send an excessively large OCSP Status Request
     extension. If that client continually requests renegotiation, sending a
     large OCSP Status Request extension each time, then there will be unbounded
     memory growth on the server. This will eventually lead to a Denial Of
     Service attack through memory exhaustion. Servers with a default
     configuration are vulnerable even if they do not support OCSP. Builds using
     the "no-ocsp" build time option are not affected.

     This issue was reported to OpenSSL by Shi Lei (Gear Team, Qihoo 360 Inc.)
     (CVE-2016-6304)
     [Matt Caswell]

  *) SSL_peek() hang on empty record

     OpenSSL 1.1.0 SSL/TLS will hang during a call to SSL_peek() if the peer
     sends an empty record. This could be exploited by a malicious peer in a
     Denial Of Service attack.

     This issue was reported to OpenSSL by Alex Gaynor.
     (CVE-2016-6305)
     [Matt Caswell]

  *) Excessive allocation of memory in tls_get_message_header() and
     dtls1_preprocess_fragment()

     A (D)TLS message includes 3 bytes for its length in the header for the
     message. This would allow for messages up to 16Mb in length. Messages of
     this length are excessive and OpenSSL includes a check to ensure that a
     peer is sending reasonably sized messages in order to avoid too much memory
     being consumed to service a connection. A flaw in the logic of version
     1.1.0 means that memory for the message is allocated too early, prior to
     the excessive message length check. Due to way memory is allocated in
     OpenSSL this could mean an attacker could force up to 21Mb to be allocated
     to service a connection. This could lead to a Denial of Service through
     memory exhaustion. However, the excessive message length check still takes
     place, and this would cause the connection to immediately fail. Assuming
     that the application calls SSL_free() on the failed conneciton in a timely
     manner then the 21Mb of allocated memory will then be immediately freed
     again. Therefore the excessive memory allocation will be transitory in
     nature. This then means that there is only a security impact if:

     1) The application does not call SSL_free() in a timely manner in the event
     that the connection fails
     or
     2) The application is working in a constrained environment where there is
     very little free memory
     or
     3) The attacker initiates multiple connection attempts such that there are
     multiple connections in a state where memory has been allocated for the
     connection; SSL_free() has not yet been called; and there is insufficient
     memory to service the multiple requests.

     Except in the instance of (1) above any Denial Of Service is likely to be
     transitory because as soon as the connection fails the memory is
     subsequently freed again in the SSL_free() call. However there is an
     increased risk during this period of application crashes due to the lack of
     memory - which would then mean a more serious Denial of Service.

     This issue was reported to OpenSSL by Shi Lei (Gear Team, Qihoo 360 Inc.)
     (CVE-2016-6307 and CVE-2016-6308)
     [Matt Caswell]

  *) solaris-x86-cc, i.e. 32-bit configuration with vendor compiler,
     had to be removed. Primary reason is that vendor assembler can't
     assemble our modules with -KPIC flag. As result it, assembly
     support, was not even available as option. But its lack means
     lack of side-channel resistant code, which is incompatible with
     security by todays standards. Fortunately gcc is readily available
     prepackaged option, which we firmly point at...
     [Andy Polyakov]

 Changes between 1.0.2h and 1.1.0  [25 Aug 2016]

  *) Windows command-line tool supports UTF-8 opt-in option for arguments
     and console input. Setting OPENSSL_WIN32_UTF8 environment variable
     (to any value) allows Windows user to access PKCS#12 file generated
     with Windows CryptoAPI and protected with non-ASCII password, as well
     as files generated under UTF-8 locale on Linux also protected with
     non-ASCII password.
     [Andy Polyakov]

  *) To mitigate the SWEET32 attack (CVE-2016-2183), 3DES cipher suites
     have been disabled by default and removed from DEFAULT, just like RC4.
     See the RC4 item below to re-enable both.
     [Rich Salz]

  *) The method for finding the storage location for the Windows RAND seed file
     has changed. First we check %RANDFILE%. If that is not set then we check
     the directories %HOME%, %USERPROFILE% and %SYSTEMROOT% in that order. If
     all else fails we fall back to C:\.
     [Matt Caswell]

  *) The EVP_EncryptUpdate() function has had its return type changed from void
     to int. A return of 0 indicates and error while a return of 1 indicates
     success.
     [Matt Caswell]

  *) The flags RSA_FLAG_NO_CONSTTIME, DSA_FLAG_NO_EXP_CONSTTIME and
     DH_FLAG_NO_EXP_CONSTTIME which previously provided the ability to switch
     off the constant time implementation for RSA, DSA and DH have been made
     no-ops and deprecated.
     [Matt Caswell]

  *) Windows RAND implementation was simplified to only get entropy by
     calling CryptGenRandom(). Various other RAND-related tickets
     were also closed.
     [Joseph Wylie Yandle, Rich Salz]

  *) The stack and lhash API's were renamed to start with OPENSSL_SK_
     and OPENSSL_LH_, respectively.  The old names are available
     with API compatibility.  They new names are now completely documented.
     [Rich Salz]

  *) Unify TYPE_up_ref(obj) methods signature.
     SSL_CTX_up_ref(), SSL_up_ref(), X509_up_ref(), EVP_PKEY_up_ref(),
     X509_CRL_up_ref(), X509_OBJECT_up_ref_count() methods are now returning an
     int (instead of void) like all others TYPE_up_ref() methods.
     So now these methods also check the return value of CRYPTO_atomic_add(),
     and the validity of object reference counter.
     [fdasilvayy@gmail.com]

  *) With Windows Visual Studio builds, the .pdb files are installed
     alongside the installed libraries and executables.  For a static
     library installation, ossl_static.pdb is the associate compiler
     generated .pdb file to be used when linking programs.
     [Richard Levitte]

  *) Remove openssl.spec.  Packaging files belong with the packagers.
     [Richard Levitte]

  *) Automatic Darwin/OSX configuration has had a refresh, it will now
     recognise x86_64 architectures automatically.  You can still decide
     to build for a different bitness with the environment variable
     KERNEL_BITS (can be 32 or 64), for example:

         KERNEL_BITS=32 ./config

     [Richard Levitte]

  *) Change default algorithms in pkcs8 utility to use PKCS#5 v2.0,
     256 bit AES and HMAC with SHA256.
     [Steve Henson]

  *) Remove support for MIPS o32 ABI on IRIX (and IRIX only).
     [Andy Polyakov]

  *) Triple-DES ciphers have been moved from HIGH to MEDIUM.
     [Rich Salz]

  *) To enable users to have their own config files and build file templates,
     Configure looks in the directory indicated by the environment variable
     OPENSSL_LOCAL_CONFIG_DIR as well as the in-source Configurations/
     directory.  On VMS, OPENSSL_LOCAL_CONFIG_DIR is expected to be a logical
     name and is used as is.
     [Richard Levitte]

  *) The following datatypes were made opaque: X509_OBJECT, X509_STORE_CTX,
     X509_STORE, X509_LOOKUP, and X509_LOOKUP_METHOD.  The unused type
     X509_CERT_FILE_CTX was removed.
     [Rich Salz]

  *) "shared" builds are now the default. To create only static libraries use
     the "no-shared" Configure option.
     [Matt Caswell]

  *) Remove the no-aes, no-hmac, no-rsa, no-sha and no-md5 Configure options.
     All of these option have not worked for some while and are fundamental
     algorithms.
     [Matt Caswell]

  *) Make various cleanup routines no-ops and mark them as deprecated. Most
     global cleanup functions are no longer required because they are handled
     via auto-deinit (see OPENSSL_init_crypto and OPENSSL_init_ssl man pages).
     Explicitly de-initing can cause problems (e.g. where a library that uses
     OpenSSL de-inits, but an application is still using it). The affected
     functions are CONF_modules_free(), ENGINE_cleanup(), OBJ_cleanup(),
     EVP_cleanup(), BIO_sock_cleanup(), CRYPTO_cleanup_all_ex_data(),
     RAND_cleanup(), SSL_COMP_free_compression_methods(), ERR_free_strings() and
     COMP_zlib_cleanup().
     [Matt Caswell]

  *) --strict-warnings no longer enables runtime debugging options
     such as REF_DEBUG. Instead, debug options are automatically
     enabled with '--debug' builds.
     [Andy Polyakov, Emilia Käsper]

  *) Made DH and DH_METHOD opaque. The structures for managing DH objects
     have been moved out of the public header files. New functions for managing
     these have been added.
     [Matt Caswell]

  *) Made RSA and RSA_METHOD opaque. The structures for managing RSA
     objects have been moved out of the public header files. New
     functions for managing these have been added.
     [Richard Levitte]

  *) Made DSA and DSA_METHOD opaque. The structures for managing DSA objects
     have been moved out of the public header files. New functions for managing
     these have been added.
     [Matt Caswell]

  *) Made BIO and BIO_METHOD opaque. The structures for managing BIOs have been
     moved out of the public header files. New functions for managing these
     have been added.
     [Matt Caswell]

  *) Removed no-rijndael as a config option. Rijndael is an old name for AES.
     [Matt Caswell]

  *) Removed the mk1mf build scripts.
     [Richard Levitte]

  *) Headers are now wrapped, if necessary, with OPENSSL_NO_xxx, so
     it is always safe to #include a header now.
     [Rich Salz]

  *) Removed the aged BC-32 config and all its supporting scripts
     [Richard Levitte]

  *) Removed support for Ultrix, Netware, and OS/2.
     [Rich Salz]

  *) Add support for HKDF.
     [Alessandro Ghedini]

  *) Add support for blake2b and blake2s
     [Bill Cox]

  *) Added support for "pipelining". Ciphers that have the
     EVP_CIPH_FLAG_PIPELINE flag set have a capability to process multiple
     encryptions/decryptions simultaneously. There are currently no built-in
     ciphers with this property but the expectation is that engines will be able
     to offer it to significantly improve throughput. Support has been extended
     into libssl so that multiple records for a single connection can be
     processed in one go (for >=TLS 1.1).
     [Matt Caswell]

  *) Added the AFALG engine. This is an async capable engine which is able to
     offload work to the Linux kernel. In this initial version it only supports
     AES128-CBC. The kernel must be version 4.1.0 or greater.
     [Catriona Lucey]

  *) OpenSSL now uses a new threading API. It is no longer necessary to
     set locking callbacks to use OpenSSL in a multi-threaded environment. There
     are two supported threading models: pthreads and windows threads. It is
     also possible to configure OpenSSL at compile time for "no-threads". The
     old threading API should no longer be used. The functions have been
     replaced with "no-op" compatibility macros.
     [Alessandro Ghedini, Matt Caswell]

  *) Modify behavior of ALPN to invoke callback after SNI/servername
     callback, such that updates to the SSL_CTX affect ALPN.
     [Todd Short]

  *) Add SSL_CIPHER queries for authentication and key-exchange.
     [Todd Short]

  *) Changes to the DEFAULT cipherlist:
       - Prefer (EC)DHE handshakes over plain RSA.
       - Prefer AEAD ciphers over legacy ciphers.
       - Prefer ECDSA over RSA when both certificates are available.
       - Prefer TLSv1.2 ciphers/PRF.
       - Remove DSS, SEED, IDEA, CAMELLIA, and AES-CCM from the
         default cipherlist.
     [Emilia Käsper]

  *) Change the ECC default curve list to be this, in order: x25519,
     secp256r1, secp521r1, secp384r1.
     [Rich Salz]

  *) RC4 based libssl ciphersuites are now classed as "weak" ciphers and are
     disabled by default. They can be re-enabled using the
     enable-weak-ssl-ciphers option to Configure.
     [Matt Caswell]

  *) If the server has ALPN configured, but supports no protocols that the
     client advertises, send a fatal "no_application_protocol" alert.
     This behaviour is SHALL in RFC 7301, though it isn't universally
     implemented by other servers.
     [Emilia Käsper]

  *) Add X25519 support.
     Add ASN.1 and EVP_PKEY methods for X25519. This includes support
     for public and private key encoding using the format documented in
     draft-ietf-curdle-pkix-02. The coresponding EVP_PKEY method supports
     key generation and key derivation.

     TLS support complies with draft-ietf-tls-rfc4492bis-08 and uses
     X25519(29).
     [Steve Henson]

  *) Deprecate SRP_VBASE_get_by_user.
     SRP_VBASE_get_by_user had inconsistent memory management behaviour.
     In order to fix an unavoidable memory leak (CVE-2016-0798),
     SRP_VBASE_get_by_user was changed to ignore the "fake user" SRP
     seed, even if the seed is configured.

     Users should use SRP_VBASE_get1_by_user instead. Note that in
     SRP_VBASE_get1_by_user, caller must free the returned value. Note
     also that even though configuring the SRP seed attempts to hide
     invalid usernames by continuing the handshake with fake
     credentials, this behaviour is not constant time and no strong
     guarantees are made that the handshake is indistinguishable from
     that of a valid user.
     [Emilia Käsper]

  *) Configuration change; it's now possible to build dynamic engines
     without having to build shared libraries and vice versa.  This
     only applies to the engines in engines/, those in crypto/engine/
     will always be built into libcrypto (i.e. "static").

     Building dynamic engines is enabled by default; to disable, use
     the configuration option "disable-dynamic-engine".

     The only requirements for building dynamic engines are the
     presence of the DSO module and building with position independent
     code, so they will also automatically be disabled if configuring
     with "disable-dso" or "disable-pic".

     The macros OPENSSL_NO_STATIC_ENGINE and OPENSSL_NO_DYNAMIC_ENGINE
     are also taken away from openssl/opensslconf.h, as they are
     irrelevant.
     [Richard Levitte]

  *) Configuration change; if there is a known flag to compile
     position independent code, it will always be applied on the
     libcrypto and libssl object files, and never on the application
     object files.  This means other libraries that use routines from
     libcrypto / libssl can be made into shared libraries regardless
     of how OpenSSL was configured.

     If this isn't desirable, the configuration options "disable-pic"
     or "no-pic" can be used to disable the use of PIC.  This will
     also disable building shared libraries and dynamic engines.
     [Richard Levitte]

  *) Removed JPAKE code.  It was experimental and has no wide use.
     [Rich Salz]

  *) The INSTALL_PREFIX Makefile variable has been renamed to
     DESTDIR.  That makes for less confusion on what this variable
     is for.  Also, the configuration option --install_prefix is
     removed.
     [Richard Levitte]

  *) Heartbeat for TLS has been removed and is disabled by default
     for DTLS; configure with enable-heartbeats.  Code that uses the
     old #define's might need to be updated.
     [Emilia Käsper, Rich Salz]

  *) Rename REF_CHECK to REF_DEBUG.
     [Rich Salz]

  *) New "unified" build system

     The "unified" build system is aimed to be a common system for all
     platforms we support.  With it comes new support for VMS.

     This system builds supports building in a different directory tree
     than the source tree.  It produces one Makefile (for unix family
     or lookalikes), or one descrip.mms (for VMS).

     The source of information to make the Makefile / descrip.mms is
     small files called 'build.info', holding the necessary
     information for each directory with source to compile, and a
     template in Configurations, like unix-Makefile.tmpl or
     descrip.mms.tmpl.

     With this change, the library names were also renamed on Windows
     and on VMS.  They now have names that are closer to the standard
     on Unix, and include the major version number, and in certain
     cases, the architecture they are built for.  See "Notes on shared
     libraries" in INSTALL.

     We rely heavily on the perl module Text::Template.
     [Richard Levitte]

  *) Added support for auto-initialisation and de-initialisation of the library.
     OpenSSL no longer requires explicit init or deinit routines to be called,
     except in certain circumstances. See the OPENSSL_init_crypto() and
     OPENSSL_init_ssl() man pages for further information.
     [Matt Caswell]

  *) The arguments to the DTLSv1_listen function have changed. Specifically the
     "peer" argument is now expected to be a BIO_ADDR object.

  *) Rewrite of BIO networking library. The BIO library lacked consistent
     support of IPv6, and adding it required some more extensive
     modifications.  This introduces the BIO_ADDR and BIO_ADDRINFO types,
     which hold all types of addresses and chains of address information.
     It also introduces a new API, with functions like BIO_socket,
     BIO_connect, BIO_listen, BIO_lookup and a rewrite of BIO_accept.
     The source/sink BIOs BIO_s_connect, BIO_s_accept and BIO_s_datagram
     have been adapted accordingly.
     [Richard Levitte]

  *) RSA_padding_check_PKCS1_type_1 now accepts inputs with and without
     the leading 0-byte.
     [Emilia Käsper]

  *) CRIME protection: disable compression by default, even if OpenSSL is
     compiled with zlib enabled. Applications can still enable compression
     by calling SSL_CTX_clear_options(ctx, SSL_OP_NO_COMPRESSION), or by
     using the SSL_CONF library to configure compression.
     [Emilia Käsper]

  *) The signature of the session callback configured with
     SSL_CTX_sess_set_get_cb was changed. The read-only input buffer
     was explicitly marked as 'const unsigned char*' instead of
     'unsigned char*'.
     [Emilia Käsper]

  *) Always DPURIFY. Remove the use of uninitialized memory in the
     RNG, and other conditional uses of DPURIFY. This makes -DPURIFY a no-op.
     [Emilia Käsper]

  *) Removed many obsolete configuration items, including
        DES_PTR, DES_RISC1, DES_RISC2, DES_INT
        MD2_CHAR, MD2_INT, MD2_LONG
        BF_PTR, BF_PTR2
        IDEA_SHORT, IDEA_LONG
        RC2_SHORT, RC2_LONG, RC4_LONG, RC4_CHUNK, RC4_INDEX
     [Rich Salz, with advice from Andy Polyakov]

  *) Many BN internals have been moved to an internal header file.
     [Rich Salz with help from Andy Polyakov]

  *) Configuration and writing out the results from it has changed.
     Files such as Makefile include/openssl/opensslconf.h and are now
     produced through general templates, such as Makefile.in and
     crypto/opensslconf.h.in and some help from the perl module
     Text::Template.

     Also, the center of configuration information is no longer
     Makefile.  Instead, Configure produces a perl module in
     configdata.pm which holds most of the config data (in the hash
     table %config), the target data that comes from the target
     configuration in one of the Configurations/*.conf files (in
     %target).
     [Richard Levitte]

  *) To clarify their intended purposes, the Configure options
     --prefix and --openssldir change their semantics, and become more
     straightforward and less interdependent.

     --prefix shall be used exclusively to give the location INSTALLTOP
     where programs, scripts, libraries, include files and manuals are
     going to be installed.  The default is now /usr/local.

     --openssldir shall be used exclusively to give the default
     location OPENSSLDIR where certificates, private keys, CRLs are
     managed.  This is also where the default openssl.cnf gets
     installed.
     If the directory given with this option is a relative path, the
     values of both the --prefix value and the --openssldir value will
     be combined to become OPENSSLDIR.
     The default for --openssldir is INSTALLTOP/ssl.

     Anyone who uses --openssldir to specify where OpenSSL is to be
     installed MUST change to use --prefix instead.
     [Richard Levitte]

  *) The GOST engine was out of date and therefore it has been removed. An up
     to date GOST engine is now being maintained in an external repository.
     See: https://wiki.openssl.org/index.php/Binaries. Libssl still retains
     support for GOST ciphersuites (these are only activated if a GOST engine
     is present).
     [Matt Caswell]

  *) EGD is no longer supported by default; use enable-egd when
     configuring.
     [Ben Kaduk and Rich Salz]

  *) The distribution now has Makefile.in files, which are used to
     create Makefile's when Configure is run.  *Configure must be run
     before trying to build now.*
     [Rich Salz]

  *) The return value for SSL_CIPHER_description() for error conditions
     has changed.
     [Rich Salz]

  *) Support for RFC6698/RFC7671 DANE TLSA peer authentication.

     Obtaining and performing DNSSEC validation of TLSA records is
     the application's responsibility.  The application provides
     the TLSA records of its choice to OpenSSL, and these are then
     used to authenticate the peer.

     The TLSA records need not even come from DNS.  They can, for
     example, be used to implement local end-entity certificate or
     trust-anchor "pinning", where the "pin" data takes the form
     of TLSA records, which can augment or replace verification
     based on the usual WebPKI public certification authorities.
     [Viktor Dukhovni]

  *) Revert default OPENSSL_NO_DEPRECATED setting.  Instead OpenSSL
     continues to support deprecated interfaces in default builds.
     However, applications are strongly advised to compile their
     source files with -DOPENSSL_API_COMPAT=0x10100000L, which hides
     the declarations of all interfaces deprecated in 0.9.8, 1.0.0
     or the 1.1.0 releases.

     In environments in which all applications have been ported to
     not use any deprecated interfaces OpenSSL's Configure script
     should be used with the --api=1.1.0 option to entirely remove
     support for the deprecated features from the library and
     unconditionally disable them in the installed headers.
     Essentially the same effect can be achieved with the "no-deprecated"
     argument to Configure, except that this will always restrict
     the build to just the latest API, rather than a fixed API
     version.

     As applications are ported to future revisions of the API,
     they should update their compile-time OPENSSL_API_COMPAT define
     accordingly, but in most cases should be able to continue to
     compile with later releases.

     The OPENSSL_API_COMPAT versions for 1.0.0, and 0.9.8 are
     0x10000000L and 0x00908000L, respectively.  However those
     versions did not support the OPENSSL_API_COMPAT feature, and
     so applications are not typically tested for explicit support
     of just the undeprecated features of either release.
     [Viktor Dukhovni]

  *) Add support for setting the minimum and maximum supported protocol.
     It can bet set via the SSL_set_min_proto_version() and
     SSL_set_max_proto_version(), or via the SSL_CONF's MinProtocol and
     MaxProtcol.  It's recommended to use the new APIs to disable
     protocols instead of disabling individual protocols using
     SSL_set_options() or SSL_CONF's Protocol.  This change also
     removes support for disabling TLS 1.2 in the OpenSSL TLS
     client at compile time by defining OPENSSL_NO_TLS1_2_CLIENT.
     [Kurt Roeckx]

  *) Support for ChaCha20 and Poly1305 added to libcrypto and libssl.
     [Andy Polyakov]

  *) New EC_KEY_METHOD, this replaces the older ECDSA_METHOD and ECDH_METHOD
     and integrates ECDSA and ECDH functionality into EC. Implementations can
     now redirect key generation and no longer need to convert to or from
     ECDSA_SIG format.

     Note: the ecdsa.h and ecdh.h headers are now no longer needed and just
     include the ec.h header file instead.
     [Steve Henson]

  *) Remove support for all 40 and 56 bit ciphers.  This includes all the export
     ciphers who are no longer supported and drops support the ephemeral RSA key
     exchange. The LOW ciphers currently doesn't have any ciphers in it.
     [Kurt Roeckx]

  *) Made EVP_MD_CTX, EVP_MD, EVP_CIPHER_CTX, EVP_CIPHER and HMAC_CTX
     opaque.  For HMAC_CTX, the following constructors and destructors
     were added:

        HMAC_CTX *HMAC_CTX_new(void);
        void HMAC_CTX_free(HMAC_CTX *ctx);

     For EVP_MD and EVP_CIPHER, complete APIs to create, fill and
     destroy such methods has been added.  See EVP_MD_meth_new(3) and
     EVP_CIPHER_meth_new(3) for documentation.

     Additional changes:
     1) EVP_MD_CTX_cleanup(), EVP_CIPHER_CTX_cleanup() and
        HMAC_CTX_cleanup() were removed.  HMAC_CTX_reset() and
        EVP_MD_CTX_reset() should be called instead to reinitialise
        an already created structure.
     2) For consistency with the majority of our object creators and
        destructors, EVP_MD_CTX_(create|destroy) were renamed to
        EVP_MD_CTX_(new|free).  The old names are retained as macros
        for deprecated builds.
     [Richard Levitte]

  *) Added ASYNC support. Libcrypto now includes the async sub-library to enable
     cryptographic operations to be performed asynchronously as long as an
     asynchronous capable engine is used. See the ASYNC_start_job() man page for
     further details. Libssl has also had this capability integrated with the
     introduction of the new mode SSL_MODE_ASYNC and associated error
     SSL_ERROR_WANT_ASYNC. See the SSL_CTX_set_mode() and SSL_get_error() man
     pages. This work was developed in partnership with Intel Corp.
     [Matt Caswell]

  *) SSL_{CTX_}set_ecdh_auto() has been removed and ECDH is support is
     always enabled now.  If you want to disable the support you should
     exclude it using the list of supported ciphers. This also means that the
     "-no_ecdhe" option has been removed from s_server.
     [Kurt Roeckx]

  *) SSL_{CTX}_set_tmp_ecdh() which can set 1 EC curve now internally calls
     SSL_{CTX_}set1_curves() which can set a list.
     [Kurt Roeckx]

  *) Remove support for SSL_{CTX_}set_tmp_ecdh_callback().  You should set the
     curve you want to support using SSL_{CTX_}set1_curves().
     [Kurt Roeckx]

  *) State machine rewrite. The state machine code has been significantly
     refactored in order to remove much duplication of code and solve issues
     with the old code (see ssl/statem/README for further details). This change
     does have some associated API changes. Notably the SSL_state() function
     has been removed and replaced by SSL_get_state which now returns an
     "OSSL_HANDSHAKE_STATE" instead of an int. SSL_set_state() has been removed
     altogether. The previous handshake states defined in ssl.h and ssl3.h have
     also been removed.
     [Matt Caswell]

  *) All instances of the string "ssleay" in the public API were replaced
     with OpenSSL (case-matching; e.g., OPENSSL_VERSION for #define's)
     Some error codes related to internal RSA_eay API's were renamed.
     [Rich Salz]

  *) The demo files in crypto/threads were moved to demo/threads.
     [Rich Salz]

  *) Removed obsolete engines: 4758cca, aep, atalla, cswift, nuron, gmp,
     sureware and ubsec.
     [Matt Caswell, Rich Salz]

  *) New ASN.1 embed macro.

     New ASN.1 macro ASN1_EMBED. This is the same as ASN1_SIMPLE except the
     structure is not allocated: it is part of the parent. That is instead of

     FOO *x;

     it must be:

     FOO x;

     This reduces memory fragmentation and make it impossible to accidentally
     set a mandatory field to NULL.

     This currently only works for some fields specifically a SEQUENCE, CHOICE,
     or ASN1_STRING type which is part of a parent SEQUENCE. Since it is
     equivalent to ASN1_SIMPLE it cannot be tagged, OPTIONAL, SET OF or
     SEQUENCE OF.
     [Steve Henson]

  *) Remove EVP_CHECK_DES_KEY, a compile-time option that never compiled.
     [Emilia Käsper]

  *) Removed DES and RC4 ciphersuites from DEFAULT. Also removed RC2 although
     in 1.0.2 EXPORT was already removed and the only RC2 ciphersuite is also
     an EXPORT one. COMPLEMENTOFDEFAULT has been updated accordingly to add
     DES and RC4 ciphersuites.
     [Matt Caswell]

  *) Rewrite EVP_DecodeUpdate (base64 decoding) to fix several bugs.
     This changes the decoding behaviour for some invalid messages,
     though the change is mostly in the more lenient direction, and
     legacy behaviour is preserved as much as possible.
     [Emilia Käsper]

  *) Fix no-stdio build.
    [ David Woodhouse <David.Woodhouse@intel.com> and also
      Ivan Nestlerode <ivan.nestlerode@sonos.com> ]

  *) New testing framework
     The testing framework has been largely rewritten and is now using
     perl and the perl modules Test::Harness and an extended variant of
     Test::More called OpenSSL::Test to do its work.  All test scripts in
     test/ have been rewritten into test recipes, and all direct calls to
     executables in test/Makefile have become individual recipes using the
     simplified testing OpenSSL::Test::Simple.

     For documentation on our testing modules, do:

        perldoc test/testlib/OpenSSL/Test/Simple.pm
        perldoc test/testlib/OpenSSL/Test.pm

     [Richard Levitte]

  *) Revamped memory debug; only -DCRYPTO_MDEBUG and -DCRYPTO_MDEBUG_ABORT
     are used; the latter aborts on memory leaks (usually checked on exit).
     Some undocumented "set malloc, etc., hooks" functions were removed
     and others were changed.  All are now documented.
     [Rich Salz]

  *) In DSA_generate_parameters_ex, if the provided seed is too short,
     return an error
     [Rich Salz and Ismo Puustinen <ismo.puustinen@intel.com>]

  *) Rewrite PSK to support ECDHE_PSK, DHE_PSK and RSA_PSK. Add ciphersuites
     from RFC4279, RFC4785, RFC5487, RFC5489.

     Thanks to Christian J. Dietrich and Giuseppe D'Angelo for the
     original RSA_PSK patch.
     [Steve Henson]

  *) Dropped support for the SSL3_FLAGS_DELAY_CLIENT_FINISHED flag. This SSLeay
     era flag was never set throughout the codebase (only read). Also removed
     SSL3_FLAGS_POP_BUFFER which was only used if
     SSL3_FLAGS_DELAY_CLIENT_FINISHED was also set.
     [Matt Caswell]

  *) Changed the default name options in the "ca", "crl", "req" and "x509"
     to be "oneline" instead of "compat".
     [Richard Levitte]

  *) Remove SSL_OP_TLS_BLOCK_PADDING_BUG. This is SSLeay legacy, we're
     not aware of clients that still exhibit this bug, and the workaround
     hasn't been working properly for a while.
     [Emilia Käsper]

  *) The return type of BIO_number_read() and BIO_number_written() as well as
     the corresponding num_read and num_write members in the BIO structure has
     changed from unsigned long to uint64_t. On platforms where an unsigned
     long is 32 bits (e.g. Windows) these counters could overflow if >4Gb is
     transferred.
     [Matt Caswell]

  *) Given the pervasive nature of TLS extensions it is inadvisable to run
     OpenSSL without support for them. It also means that maintaining
     the OPENSSL_NO_TLSEXT option within the code is very invasive (and probably
     not well tested). Therefore the OPENSSL_NO_TLSEXT option has been removed.
     [Matt Caswell]

  *) Removed support for the two export grade static DH ciphersuites
     EXP-DH-RSA-DES-CBC-SHA and EXP-DH-DSS-DES-CBC-SHA. These two ciphersuites
     were newly added (along with a number of other static DH ciphersuites) to
     1.0.2. However the two export ones have *never* worked since they were
     introduced. It seems strange in any case to be adding new export
     ciphersuites, and given "logjam" it also does not seem correct to fix them.
     [Matt Caswell]

  *) Version negotiation has been rewritten. In particular SSLv23_method(),
     SSLv23_client_method() and SSLv23_server_method() have been deprecated,
     and turned into macros which simply call the new preferred function names
     TLS_method(), TLS_client_method() and TLS_server_method(). All new code
     should use the new names instead. Also as part of this change the ssl23.h
     header file has been removed.
     [Matt Caswell]

  *) Support for Kerberos ciphersuites in TLS (RFC2712) has been removed. This
     code and the associated standard is no longer considered fit-for-purpose.
     [Matt Caswell]

  *) RT2547 was closed.  When generating a private key, try to make the
     output file readable only by the owner.  This behavior change might
     be noticeable when interacting with other software.

  *) Documented all exdata functions.  Added CRYPTO_free_ex_index.
     Added a test.
     [Rich Salz]

  *) Added HTTP GET support to the ocsp command.
     [Rich Salz]

  *) Changed default digest for the dgst and enc commands from MD5 to
     sha256
     [Rich Salz]

  *) RAND_pseudo_bytes has been deprecated. Users should use RAND_bytes instead.
     [Matt Caswell]

  *) Added support for TLS extended master secret from
     draft-ietf-tls-session-hash-03.txt. Thanks for Alfredo Pironti for an
     initial patch which was a great help during development.
     [Steve Henson]

  *) All libssl internal structures have been removed from the public header
     files, and the OPENSSL_NO_SSL_INTERN option has been removed (since it is
     now redundant). Users should not attempt to access internal structures
     directly. Instead they should use the provided API functions.
     [Matt Caswell]

  *) config has been changed so that by default OPENSSL_NO_DEPRECATED is used.
     Access to deprecated functions can be re-enabled by running config with
     "enable-deprecated". In addition applications wishing to use deprecated
     functions must define OPENSSL_USE_DEPRECATED. Note that this new behaviour
     will, by default, disable some transitive includes that previously existed
     in the header files (e.g. ec.h will no longer, by default, include bn.h)
     [Matt Caswell]

  *) Added support for OCB mode. OpenSSL has been granted a patent license
     compatible with the OpenSSL license for use of OCB. Details are available
     at https://www.openssl.org/source/OCB-patent-grant-OpenSSL.pdf. Support
     for OCB can be removed by calling config with no-ocb.
     [Matt Caswell]

  *) SSLv2 support has been removed.  It still supports receiving a SSLv2
     compatible client hello.
     [Kurt Roeckx]

  *) Increased the minimal RSA keysize from 256 to 512 bits [Rich Salz],
     done while fixing the error code for the key-too-small case.
     [Annie Yousar <a.yousar@informatik.hu-berlin.de>]

  *) CA.sh has been removmed; use CA.pl instead.
     [Rich Salz]

  *) Removed old DES API.
     [Rich Salz]

  *) Remove various unsupported platforms:
        Sony NEWS4
        BEOS and BEOS_R5
        NeXT
        SUNOS
        MPE/iX
        Sinix/ReliantUNIX RM400
        DGUX
        NCR
        Tandem
        Cray
        16-bit platforms such as WIN16
     [Rich Salz]

  *) Clean up OPENSSL_NO_xxx #define's
        Use setbuf() and remove OPENSSL_NO_SETVBUF_IONBF
        Rename OPENSSL_SYSNAME_xxx to OPENSSL_SYS_xxx
        OPENSSL_NO_EC{DH,DSA} merged into OPENSSL_NO_EC
        OPENSSL_NO_RIPEMD160, OPENSSL_NO_RIPEMD merged into OPENSSL_NO_RMD160
        OPENSSL_NO_FP_API merged into OPENSSL_NO_STDIO
        Remove OPENSSL_NO_BIO OPENSSL_NO_BUFFER OPENSSL_NO_CHAIN_VERIFY
        OPENSSL_NO_EVP OPENSSL_NO_FIPS_ERR OPENSSL_NO_HASH_COMP
        OPENSSL_NO_LHASH OPENSSL_NO_OBJECT OPENSSL_NO_SPEED OPENSSL_NO_STACK
        OPENSSL_NO_X509 OPENSSL_NO_X509_VERIFY
        Remove MS_STATIC; it's a relic from platforms <32 bits.
     [Rich Salz]

  *) Cleaned up dead code
        Remove all but one '#ifdef undef' which is to be looked at.
     [Rich Salz]

  *) Clean up calling of xxx_free routines.
        Just like free(), fix most of the xxx_free routines to accept
        NULL.  Remove the non-null checks from callers.  Save much code.
     [Rich Salz]

  *) Add secure heap for storage of private keys (when possible).
     Add BIO_s_secmem(), CBIGNUM, etc.
     Contributed by Akamai Technologies under our Corporate CLA.
     [Rich Salz]

  *) Experimental support for a new, fast, unbiased prime candidate generator,
     bn_probable_prime_dh_coprime(). Not currently used by any prime generator.
     [Felix Laurie von Massenbach <felix@erbridge.co.uk>]

  *) New output format NSS in the sess_id command line tool. This allows
     exporting the session id and the master key in NSS keylog format.
     [Martin Kaiser <martin@kaiser.cx>]

  *) Harmonize version and its documentation. -f flag is used to display
     compilation flags.
     [mancha <mancha1@zoho.com>]

  *) Fix eckey_priv_encode so it immediately returns an error upon a failure
     in i2d_ECPrivateKey.  Thanks to Ted Unangst for feedback on this issue.
     [mancha <mancha1@zoho.com>]

  *) Fix some double frees. These are not thought to be exploitable.
     [mancha <mancha1@zoho.com>]

  *) A missing bounds check in the handling of the TLS heartbeat extension
     can be used to reveal up to 64k of memory to a connected client or
     server.

     Thanks for Neel Mehta of Google Security for discovering this bug and to
     Adam Langley <agl@chromium.org> and Bodo Moeller <bmoeller@acm.org> for
     preparing the fix (CVE-2014-0160)
     [Adam Langley, Bodo Moeller]

  *) Fix for the attack described in the paper "Recovering OpenSSL
     ECDSA Nonces Using the FLUSH+RELOAD Cache Side-channel Attack"
     by Yuval Yarom and Naomi Benger. Details can be obtained from:
     http://eprint.iacr.org/2014/140

     Thanks to Yuval Yarom and Naomi Benger for discovering this
     flaw and to Yuval Yarom for supplying a fix (CVE-2014-0076)
     [Yuval Yarom and Naomi Benger]

  *) Use algorithm specific chains in SSL_CTX_use_certificate_chain_file():
     this fixes a limitation in previous versions of OpenSSL.
     [Steve Henson]

  *) Experimental encrypt-then-mac support.
    
     Experimental support for encrypt then mac from
     draft-gutmann-tls-encrypt-then-mac-02.txt

     To enable it set the appropriate extension number (0x42 for the test
     server) using e.g. -DTLSEXT_TYPE_encrypt_then_mac=0x42
 
     For non-compliant peers (i.e. just about everything) this should have no
     effect.

     WARNING: EXPERIMENTAL, SUBJECT TO CHANGE.

     [Steve Henson]

  *) Add EVP support for key wrapping algorithms, to avoid problems with
     existing code the flag EVP_CIPHER_CTX_WRAP_ALLOW has to be set in
     the EVP_CIPHER_CTX or an error is returned. Add AES and DES3 wrap
     algorithms and include tests cases.
     [Steve Henson]

  *) Extend CMS code to support RSA-PSS signatures and RSA-OAEP for
     enveloped data.
     [Steve Henson]

  *) Extended RSA OAEP support via EVP_PKEY API. Options to specify digest,
     MGF1 digest and OAEP label.
     [Steve Henson]

  *) Make openssl verify return errors.
     [Chris Palmer <palmer@google.com> and Ben Laurie]

  *) New function ASN1_TIME_diff to calculate the difference between two
     ASN1_TIME structures or one structure and the current time.
     [Steve Henson]

  *) Update fips_test_suite to support multiple command line options. New
     test to induce all self test errors in sequence and check expected
     failures.
     [Steve Henson]

  *) Add FIPS_{rsa,dsa,ecdsa}_{sign,verify} functions which digest and
     sign or verify all in one operation.
     [Steve Henson]

  *) Add fips_algvs: a multicall fips utility incorporating all the algorithm
     test programs and fips_test_suite. Includes functionality to parse
     the minimal script output of fipsalgest.pl directly.
     [Steve Henson]

  *) Add authorisation parameter to FIPS_module_mode_set().
     [Steve Henson]

  *) Add FIPS selftest for ECDH algorithm using P-224 and B-233 curves.
     [Steve Henson]

  *) Use separate DRBG fields for internal and external flags. New function
     FIPS_drbg_health_check() to perform on demand health checking. Add
     generation tests to fips_test_suite with reduced health check interval to 
     demonstrate periodic health checking. Add "nodh" option to
     fips_test_suite to skip very slow DH test.
     [Steve Henson]

  *) New function FIPS_get_cipherbynid() to lookup FIPS supported ciphers
     based on NID.
     [Steve Henson]

  *) More extensive health check for DRBG checking many more failure modes.
     New function FIPS_selftest_drbg_all() to handle every possible DRBG
     combination: call this in fips_test_suite.
     [Steve Henson]

  *) Add support for canonical generation of DSA parameter 'g'. See 
     FIPS 186-3 A.2.3.

  *) Add support for HMAC DRBG from SP800-90. Update DRBG algorithm test and
     POST to handle HMAC cases.
     [Steve Henson]

  *) Add functions FIPS_module_version() and FIPS_module_version_text()
     to return numerical and string versions of the FIPS module number.
     [Steve Henson]

  *) Rename FIPS_mode_set and FIPS_mode to FIPS_module_mode_set and
     FIPS_module_mode. FIPS_mode and FIPS_mode_set will be implemented
     outside the validated module in the FIPS capable OpenSSL.
     [Steve Henson]

  *) Minor change to DRBG entropy callback semantics. In some cases
     there is no multiple of the block length between min_len and
     max_len. Allow the callback to return more than max_len bytes
     of entropy but discard any extra: it is the callback's responsibility
     to ensure that the extra data discarded does not impact the
     requested amount of entropy.
     [Steve Henson]

  *) Add PRNG security strength checks to RSA, DSA and ECDSA using 
     information in FIPS186-3, SP800-57 and SP800-131A.
     [Steve Henson]

  *) CCM support via EVP. Interface is very similar to GCM case except we
     must supply all data in one chunk (i.e. no update, final) and the
     message length must be supplied if AAD is used. Add algorithm test
     support.
     [Steve Henson]

  *) Initial version of POST overhaul. Add POST callback to allow the status
     of POST to be monitored and/or failures induced. Modify fips_test_suite
     to use callback. Always run all selftests even if one fails.
     [Steve Henson]

  *) XTS support including algorithm test driver in the fips_gcmtest program.
     Note: this does increase the maximum key length from 32 to 64 bytes but
     there should be no binary compatibility issues as existing applications
     will never use XTS mode.
     [Steve Henson]

  *) Extensive reorganisation of FIPS PRNG behaviour. Remove all dependencies
     to OpenSSL RAND code and replace with a tiny FIPS RAND API which also
     performs algorithm blocking for unapproved PRNG types. Also do not
     set PRNG type in FIPS_mode_set(): leave this to the application.
     Add default OpenSSL DRBG handling: sets up FIPS PRNG and seeds with
     the standard OpenSSL PRNG: set additional data to a date time vector.
     [Steve Henson]

  *) Rename old X9.31 PRNG functions of the form FIPS_rand* to FIPS_x931*.
     This shouldn't present any incompatibility problems because applications
     shouldn't be using these directly and any that are will need to rethink
     anyway as the X9.31 PRNG is now deprecated by FIPS 140-2
     [Steve Henson]

  *) Extensive self tests and health checking required by SP800-90 DRBG.
     Remove strength parameter from FIPS_drbg_instantiate and always
     instantiate at maximum supported strength.
     [Steve Henson]

  *) Add ECDH code to fips module and fips_ecdhvs for primitives only testing.
     [Steve Henson]

  *) New algorithm test program fips_dhvs to handle DH primitives only testing.
     [Steve Henson]

  *) New function DH_compute_key_padded() to compute a DH key and pad with
     leading zeroes if needed: this complies with SP800-56A et al.
     [Steve Henson]

  *) Initial implementation of SP800-90 DRBGs for Hash and CTR. Not used by
     anything, incomplete, subject to change and largely untested at present.
     [Steve Henson]

  *) Modify fipscanisteronly build option to only build the necessary object
     files by filtering FIPS_EX_OBJ through a perl script in crypto/Makefile.
     [Steve Henson]

  *) Add experimental option FIPSSYMS to give all symbols in
     fipscanister.o and FIPS or fips prefix. This will avoid
     conflicts with future versions of OpenSSL. Add perl script
     util/fipsas.pl to preprocess assembly language source files
     and rename any affected symbols.
     [Steve Henson]

  *) Add selftest checks and algorithm block of non-fips algorithms in
     FIPS mode. Remove DES2 from selftests.
     [Steve Henson]

  *) Add ECDSA code to fips module. Add tiny fips_ecdsa_check to just
     return internal method without any ENGINE dependencies. Add new
     tiny fips sign and verify functions.
     [Steve Henson]

  *) New build option no-ec2m to disable characteristic 2 code.
     [Steve Henson]

  *) New build option "fipscanisteronly". This only builds fipscanister.o
     and (currently) associated fips utilities. Uses the file Makefile.fips
     instead of Makefile.org as the prototype.
     [Steve Henson]

  *) Add some FIPS mode restrictions to GCM. Add internal IV generator.
     Update fips_gcmtest to use IV generator.
     [Steve Henson]

  *) Initial, experimental EVP support for AES-GCM. AAD can be input by
     setting output buffer to NULL. The *Final function must be
     called although it will not retrieve any additional data. The tag
     can be set or retrieved with a ctrl. The IV length is by default 12
     bytes (96 bits) but can be set to an alternative value. If the IV
     length exceeds the maximum IV length (currently 16 bytes) it cannot be
     set before the key. 
     [Steve Henson]

  *) New flag in ciphers: EVP_CIPH_FLAG_CUSTOM_CIPHER. This means the
     underlying do_cipher function handles all cipher semantics itself
     including padding and finalisation. This is useful if (for example)
     an ENGINE cipher handles block padding itself. The behaviour of
     do_cipher is subtly changed if this flag is set: the return value
     is the number of characters written to the output buffer (zero is
     no longer an error code) or a negative error code. Also if the
     input buffer is NULL and length 0 finalisation should be performed.
     [Steve Henson]

  *) If a candidate issuer certificate is already part of the constructed
     path ignore it: new debug notification X509_V_ERR_PATH_LOOP for this case.
     [Steve Henson]

  *) Improve forward-security support: add functions

       void SSL_CTX_set_not_resumable_session_callback(SSL_CTX *ctx, int (*cb)(SSL *ssl, int is_forward_secure))
       void SSL_set_not_resumable_session_callback(SSL *ssl, int (*cb)(SSL *ssl, int is_forward_secure))

     for use by SSL/TLS servers; the callback function will be called whenever a
     new session is created, and gets to decide whether the session may be
     cached to make it resumable (return 0) or not (return 1).  (As by the
     SSL/TLS protocol specifications, the session_id sent by the server will be
     empty to indicate that the session is not resumable; also, the server will
     not generate RFC 4507 (RFC 5077) session tickets.)

     A simple reasonable callback implementation is to return is_forward_secure.
     This parameter will be set to 1 or 0 depending on the ciphersuite selected
     by the SSL/TLS server library, indicating whether it can provide forward
     security.
     [Emilia Käsper <emilia.kasper@esat.kuleuven.be> (Google)]

  *) New -verify_name option in command line utilities to set verification
     parameters by name.
     [Steve Henson]

  *) Initial CMAC implementation. WARNING: EXPERIMENTAL, API MAY CHANGE.
     Add CMAC pkey methods.
     [Steve Henson]

  *) Experimental renegotiation in s_server -www mode. If the client 
     browses /reneg connection is renegotiated. If /renegcert it is
     renegotiated requesting a certificate.
     [Steve Henson]

  *) Add an "external" session cache for debugging purposes to s_server. This
     should help trace issues which normally are only apparent in deployed
     multi-process servers.
     [Steve Henson]

  *) Extensive audit of libcrypto with DEBUG_UNUSED. Fix many cases where
     return value is ignored. NB. The functions RAND_add(), RAND_seed(),
     BIO_set_cipher() and some obscure PEM functions were changed so they
     can now return an error. The RAND changes required a change to the
     RAND_METHOD structure.
     [Steve Henson]

  *) New macro __owur for "OpenSSL Warn Unused Result". This makes use of
     a gcc attribute to warn if the result of a function is ignored. This
     is enable if DEBUG_UNUSED is set. Add to several functions in evp.h
     whose return value is often ignored. 
     [Steve Henson]

  *) New -noct, -requestct, -requirect and -ctlogfile options for s_client.
     These allow SCTs (signed certificate timestamps) to be requested and
     validated when establishing a connection.
     [Rob Percival <robpercival@google.com>]

 Changes between 1.0.2g and 1.0.2h [3 May 2016]

  *) Prevent padding oracle in AES-NI CBC MAC check

     A MITM attacker can use a padding oracle attack to decrypt traffic
     when the connection uses an AES CBC cipher and the server support
     AES-NI.

     This issue was introduced as part of the fix for Lucky 13 padding
     attack (CVE-2013-0169). The padding check was rewritten to be in
     constant time by making sure that always the same bytes are read and
     compared against either the MAC or padding bytes. But it no longer
     checked that there was enough data to have both the MAC and padding
     bytes.

     This issue was reported by Juraj Somorovsky using TLS-Attacker.
     (CVE-2016-2107)
     [Kurt Roeckx]

  *) Fix EVP_EncodeUpdate overflow

     An overflow can occur in the EVP_EncodeUpdate() function which is used for
     Base64 encoding of binary data. If an attacker is able to supply very large
     amounts of input data then a length check can overflow resulting in a heap
     corruption.

     Internally to OpenSSL the EVP_EncodeUpdate() function is primarily used by
     the PEM_write_bio* family of functions. These are mainly used within the
     OpenSSL command line applications, so any application which processes data
     from an untrusted source and outputs it as a PEM file should be considered
     vulnerable to this issue. User applications that call these APIs directly
     with large amounts of untrusted data may also be vulnerable.

     This issue was reported by Guido Vranken.
     (CVE-2016-2105)
     [Matt Caswell]

  *) Fix EVP_EncryptUpdate overflow

     An overflow can occur in the EVP_EncryptUpdate() function. If an attacker
     is able to supply very large amounts of input data after a previous call to
     EVP_EncryptUpdate() with a partial block then a length check can overflow
     resulting in a heap corruption. Following an analysis of all OpenSSL
     internal usage of the EVP_EncryptUpdate() function all usage is one of two
     forms. The first form is where the EVP_EncryptUpdate() call is known to be
     the first called function after an EVP_EncryptInit(), and therefore that
     specific call must be safe. The second form is where the length passed to
     EVP_EncryptUpdate() can be seen from the code to be some small value and
     therefore there is no possibility of an overflow. Since all instances are
     one of these two forms, it is believed that there can be no overflows in
     internal code due to this problem. It should be noted that
     EVP_DecryptUpdate() can call EVP_EncryptUpdate() in certain code paths.
     Also EVP_CipherUpdate() is a synonym for EVP_EncryptUpdate(). All instances
     of these calls have also been analysed too and it is believed there are no
     instances in internal usage where an overflow could occur.

     This issue was reported by Guido Vranken.
     (CVE-2016-2106)
     [Matt Caswell]

  *) Prevent ASN.1 BIO excessive memory allocation

     When ASN.1 data is read from a BIO using functions such as d2i_CMS_bio()
     a short invalid encoding can cause allocation of large amounts of memory
     potentially consuming excessive resources or exhausting memory.

     Any application parsing untrusted data through d2i BIO functions is
     affected. The memory based functions such as d2i_X509() are *not* affected.
     Since the memory based functions are used by the TLS library, TLS
     applications are not affected.

     This issue was reported by Brian Carpenter.
     (CVE-2016-2109)
     [Stephen Henson]

  *) EBCDIC overread

     ASN1 Strings that are over 1024 bytes can cause an overread in applications
     using the X509_NAME_oneline() function on EBCDIC systems. This could result
     in arbitrary stack data being returned in the buffer.

     This issue was reported by Guido Vranken.
     (CVE-2016-2176)
     [Matt Caswell]

  *) Modify behavior of ALPN to invoke callback after SNI/servername
     callback, such that updates to the SSL_CTX affect ALPN.
     [Todd Short]

  *) Remove LOW from the DEFAULT cipher list.  This removes singles DES from the
     default.
     [Kurt Roeckx]

  *) Only remove the SSLv2 methods with the no-ssl2-method option. When the
     methods are enabled and ssl2 is disabled the methods return NULL.
     [Kurt Roeckx]

 Changes between 1.0.2f and 1.0.2g [1 Mar 2016]

  * Disable weak ciphers in SSLv3 and up in default builds of OpenSSL.
    Builds that are not configured with "enable-weak-ssl-ciphers" will not
    provide any "EXPORT" or "LOW" strength ciphers.
    [Viktor Dukhovni]

  * Disable SSLv2 default build, default negotiation and weak ciphers.  SSLv2
    is by default disabled at build-time.  Builds that are not configured with
    "enable-ssl2" will not support SSLv2.  Even if "enable-ssl2" is used,
    users who want to negotiate SSLv2 via the version-flexible SSLv23_method()
    will need to explicitly call either of:

        SSL_CTX_clear_options(ctx, SSL_OP_NO_SSLv2);
    or
        SSL_clear_options(ssl, SSL_OP_NO_SSLv2);

    as appropriate.  Even if either of those is used, or the application
    explicitly uses the version-specific SSLv2_method() or its client and
    server variants, SSLv2 ciphers vulnerable to exhaustive search key
    recovery have been removed.  Specifically, the SSLv2 40-bit EXPORT
    ciphers, and SSLv2 56-bit DES are no longer available.
    (CVE-2016-0800)
    [Viktor Dukhovni]

  *) Fix a double-free in DSA code

     A double free bug was discovered when OpenSSL parses malformed DSA private
     keys and could lead to a DoS attack or memory corruption for applications
     that receive DSA private keys from untrusted sources.  This scenario is
     considered rare.

     This issue was reported to OpenSSL by Adam Langley(Google/BoringSSL) using
     libFuzzer.
     (CVE-2016-0705)
     [Stephen Henson]

  *) Disable SRP fake user seed to address a server memory leak.

     Add a new method SRP_VBASE_get1_by_user that handles the seed properly.

     SRP_VBASE_get_by_user had inconsistent memory management behaviour.
     In order to fix an unavoidable memory leak, SRP_VBASE_get_by_user
     was changed to ignore the "fake user" SRP seed, even if the seed
     is configured.

     Users should use SRP_VBASE_get1_by_user instead. Note that in
     SRP_VBASE_get1_by_user, caller must free the returned value. Note
     also that even though configuring the SRP seed attempts to hide
     invalid usernames by continuing the handshake with fake
     credentials, this behaviour is not constant time and no strong
     guarantees are made that the handshake is indistinguishable from
     that of a valid user.
     (CVE-2016-0798)
     [Emilia Käsper]

  *) Fix BN_hex2bn/BN_dec2bn NULL pointer deref/heap corruption

     In the BN_hex2bn function the number of hex digits is calculated using an
     int value |i|. Later |bn_expand| is called with a value of |i * 4|. For
     large values of |i| this can result in |bn_expand| not allocating any
     memory because |i * 4| is negative. This can leave the internal BIGNUM data
     field as NULL leading to a subsequent NULL ptr deref. For very large values
     of |i|, the calculation |i * 4| could be a positive value smaller than |i|.
     In this case memory is allocated to the internal BIGNUM data field, but it
     is insufficiently sized leading to heap corruption. A similar issue exists
     in BN_dec2bn. This could have security consequences if BN_hex2bn/BN_dec2bn
     is ever called by user applications with very large untrusted hex/dec data.
     This is anticipated to be a rare occurrence.

     All OpenSSL internal usage of these functions use data that is not expected
     to be untrusted, e.g. config file data or application command line
     arguments. If user developed applications generate config file data based
     on untrusted data then it is possible that this could also lead to security
     consequences. This is also anticipated to be rare.

     This issue was reported to OpenSSL by Guido Vranken.
     (CVE-2016-0797)
     [Matt Caswell]

  *) Fix memory issues in BIO_*printf functions

     The internal |fmtstr| function used in processing a "%s" format string in
     the BIO_*printf functions could overflow while calculating the length of a
     string and cause an OOB read when printing very long strings.

     Additionally the internal |doapr_outch| function can attempt to write to an
     OOB memory location (at an offset from the NULL pointer) in the event of a
     memory allocation failure. In 1.0.2 and below this could be caused where
     the size of a buffer to be allocated is greater than INT_MAX. E.g. this
     could be in processing a very long "%s" format string. Memory leaks can
     also occur.

     The first issue may mask the second issue dependent on compiler behaviour.
     These problems could enable attacks where large amounts of untrusted data
     is passed to the BIO_*printf functions. If applications use these functions
     in this way then they could be vulnerable. OpenSSL itself uses these
     functions when printing out human-readable dumps of ASN.1 data. Therefore
     applications that print this data could be vulnerable if the data is from
     untrusted sources. OpenSSL command line applications could also be
     vulnerable where they print out ASN.1 data, or if untrusted data is passed
     as command line arguments.

     Libssl is not considered directly vulnerable. Additionally certificates etc
     received via remote connections via libssl are also unlikely to be able to
     trigger these issues because of message size limits enforced within libssl.

     This issue was reported to OpenSSL Guido Vranken.
     (CVE-2016-0799)
     [Matt Caswell]

  *) Side channel attack on modular exponentiation

     A side-channel attack was found which makes use of cache-bank conflicts on
     the Intel Sandy-Bridge microarchitecture which could lead to the recovery
     of RSA keys.  The ability to exploit this issue is limited as it relies on
     an attacker who has control of code in a thread running on the same
     hyper-threaded core as the victim thread which is performing decryptions.

     This issue was reported to OpenSSL by Yuval Yarom, The University of
     Adelaide and NICTA, Daniel Genkin, Technion and Tel Aviv University, and
     Nadia Heninger, University of Pennsylvania with more information at
     http://cachebleed.info.
     (CVE-2016-0702)
     [Andy Polyakov]

  *) Change the req app to generate a 2048-bit RSA/DSA key by default,
     if no keysize is specified with default_bits. This fixes an
     omission in an earlier change that changed all RSA/DSA key generation
     apps to use 2048 bits by default.
     [Emilia Käsper]

 Changes between 1.0.2e and 1.0.2f [28 Jan 2016]
  *) DH small subgroups

     Historically OpenSSL only ever generated DH parameters based on "safe"
     primes. More recently (in version 1.0.2) support was provided for
     generating X9.42 style parameter files such as those required for RFC 5114
     support. The primes used in such files may not be "safe". Where an
     application is using DH configured with parameters based on primes that are
     not "safe" then an attacker could use this fact to find a peer's private
     DH exponent. This attack requires that the attacker complete multiple
     handshakes in which the peer uses the same private DH exponent. For example
     this could be used to discover a TLS server's private DH exponent if it's
     reusing the private DH exponent or it's using a static DH ciphersuite.

     OpenSSL provides the option SSL_OP_SINGLE_DH_USE for ephemeral DH (DHE) in
     TLS. It is not on by default. If the option is not set then the server
     reuses the same private DH exponent for the life of the server process and
     would be vulnerable to this attack. It is believed that many popular
     applications do set this option and would therefore not be at risk.

     The fix for this issue adds an additional check where a "q" parameter is
     available (as is the case in X9.42 based parameters). This detects the
     only known attack, and is the only possible defense for static DH
     ciphersuites. This could have some performance impact.

     Additionally the SSL_OP_SINGLE_DH_USE option has been switched on by
     default and cannot be disabled. This could have some performance impact.

     This issue was reported to OpenSSL by Antonio Sanso (Adobe).
     (CVE-2016-0701)
     [Matt Caswell]

  *) SSLv2 doesn't block disabled ciphers

     A malicious client can negotiate SSLv2 ciphers that have been disabled on
     the server and complete SSLv2 handshakes even if all SSLv2 ciphers have
     been disabled, provided that the SSLv2 protocol was not also disabled via
     SSL_OP_NO_SSLv2.

     This issue was reported to OpenSSL on 26th December 2015 by Nimrod Aviram
     and Sebastian Schinzel.
     (CVE-2015-3197)
     [Viktor Dukhovni]

 Changes between 1.0.2d and 1.0.2e [3 Dec 2015]

  *) BN_mod_exp may produce incorrect results on x86_64

     There is a carry propagating bug in the x86_64 Montgomery squaring
     procedure. No EC algorithms are affected. Analysis suggests that attacks
     against RSA and DSA as a result of this defect would be very difficult to
     perform and are not believed likely. Attacks against DH are considered just
     feasible (although very difficult) because most of the work necessary to
     deduce information about a private key may be performed offline. The amount
     of resources required for such an attack would be very significant and
     likely only accessible to a limited number of attackers. An attacker would
     additionally need online access to an unpatched system using the target
     private key in a scenario with persistent DH parameters and a private
     key that is shared between multiple clients. For example this can occur by
     default in OpenSSL DHE based SSL/TLS ciphersuites.

     This issue was reported to OpenSSL by Hanno Böck.
     (CVE-2015-3193)
     [Andy Polyakov]

  *) Certificate verify crash with missing PSS parameter

     The signature verification routines will crash with a NULL pointer
     dereference if presented with an ASN.1 signature using the RSA PSS
     algorithm and absent mask generation function parameter. Since these
     routines are used to verify certificate signature algorithms this can be
     used to crash any certificate verification operation and exploited in a
     DoS attack. Any application which performs certificate verification is
     vulnerable including OpenSSL clients and servers which enable client
     authentication.

     This issue was reported to OpenSSL by Loïc Jonas Etienne (Qnective AG).
     (CVE-2015-3194)
     [Stephen Henson]

  *) X509_ATTRIBUTE memory leak

     When presented with a malformed X509_ATTRIBUTE structure OpenSSL will leak
     memory. This structure is used by the PKCS#7 and CMS routines so any
     application which reads PKCS#7 or CMS data from untrusted sources is
     affected. SSL/TLS is not affected.

     This issue was reported to OpenSSL by Adam Langley (Google/BoringSSL) using
     libFuzzer.
     (CVE-2015-3195)
     [Stephen Henson]

  *) Rewrite EVP_DecodeUpdate (base64 decoding) to fix several bugs.
     This changes the decoding behaviour for some invalid messages,
     though the change is mostly in the more lenient direction, and
     legacy behaviour is preserved as much as possible.
     [Emilia Käsper]

  *) In DSA_generate_parameters_ex, if the provided seed is too short,
     return an error
     [Rich Salz and Ismo Puustinen <ismo.puustinen@intel.com>]

 Changes between 1.0.2c and 1.0.2d [9 Jul 2015]

  *) Alternate chains certificate forgery

     During certificate verification, OpenSSL will attempt to find an
     alternative certificate chain if the first attempt to build such a chain
     fails. An error in the implementation of this logic can mean that an
     attacker could cause certain checks on untrusted certificates to be
     bypassed, such as the CA flag, enabling them to use a valid leaf
     certificate to act as a CA and "issue" an invalid certificate.

     This issue was reported to OpenSSL by Adam Langley/David Benjamin
     (Google/BoringSSL).
     [Matt Caswell]

 Changes between 1.0.2b and 1.0.2c [12 Jun 2015]

  *) Fix HMAC ABI incompatibility. The previous version introduced an ABI
     incompatibility in the handling of HMAC. The previous ABI has now been
     restored.
     [Matt Caswell]

 Changes between 1.0.2a and 1.0.2b [11 Jun 2015]

  *) Malformed ECParameters causes infinite loop

     When processing an ECParameters structure OpenSSL enters an infinite loop
     if the curve specified is over a specially malformed binary polynomial
     field.

     This can be used to perform denial of service against any
     system which processes public keys, certificate requests or
     certificates.  This includes TLS clients and TLS servers with
     client authentication enabled.

     This issue was reported to OpenSSL by Joseph Barr-Pixton.
     (CVE-2015-1788)
     [Andy Polyakov]

  *) Exploitable out-of-bounds read in X509_cmp_time

     X509_cmp_time does not properly check the length of the ASN1_TIME
     string and can read a few bytes out of bounds. In addition,
     X509_cmp_time accepts an arbitrary number of fractional seconds in the
     time string.

     An attacker can use this to craft malformed certificates and CRLs of
     various sizes and potentially cause a segmentation fault, resulting in
     a DoS on applications that verify certificates or CRLs. TLS clients
     that verify CRLs are affected. TLS clients and servers with client
     authentication enabled may be affected if they use custom verification
     callbacks.

     This issue was reported to OpenSSL by Robert Swiecki (Google), and
     independently by Hanno Böck.
     (CVE-2015-1789)
     [Emilia Käsper]

  *) PKCS7 crash with missing EnvelopedContent

     The PKCS#7 parsing code does not handle missing inner EncryptedContent
     correctly. An attacker can craft malformed ASN.1-encoded PKCS#7 blobs
     with missing content and trigger a NULL pointer dereference on parsing.

     Applications that decrypt PKCS#7 data or otherwise parse PKCS#7
     structures from untrusted sources are affected. OpenSSL clients and
     servers are not affected.

     This issue was reported to OpenSSL by Michal Zalewski (Google).
     (CVE-2015-1790)
     [Emilia Käsper]

  *) CMS verify infinite loop with unknown hash function

     When verifying a signedData message the CMS code can enter an infinite loop
     if presented with an unknown hash function OID. This can be used to perform
     denial of service against any system which verifies signedData messages using
     the CMS code.
     This issue was reported to OpenSSL by Johannes Bauer.
     (CVE-2015-1792)
     [Stephen Henson]

  *) Race condition handling NewSessionTicket

     If a NewSessionTicket is received by a multi-threaded client when attempting to
     reuse a previous ticket then a race condition can occur potentially leading to
     a double free of the ticket data.
     (CVE-2015-1791)
     [Matt Caswell]

  *) Only support 256-bit or stronger elliptic curves with the
     'ecdh_auto' setting (server) or by default (client). Of supported
     curves, prefer P-256 (both).
     [Emilia Kasper]

 Changes between 1.0.2 and 1.0.2a [19 Mar 2015]

  *) ClientHello sigalgs DoS fix

     If a client connects to an OpenSSL 1.0.2 server and renegotiates with an
     invalid signature algorithms extension a NULL pointer dereference will
     occur. This can be exploited in a DoS attack against the server.

     This issue was was reported to OpenSSL by David Ramos of Stanford
     University.
     (CVE-2015-0291)
     [Stephen Henson and Matt Caswell]

  *) Multiblock corrupted pointer fix

     OpenSSL 1.0.2 introduced the "multiblock" performance improvement. This
     feature only applies on 64 bit x86 architecture platforms that support AES
     NI instructions. A defect in the implementation of "multiblock" can cause
     OpenSSL's internal write buffer to become incorrectly set to NULL when
     using non-blocking IO. Typically, when the user application is using a
     socket BIO for writing, this will only result in a failed connection.
     However if some other BIO is used then it is likely that a segmentation
     fault will be triggered, thus enabling a potential DoS attack.

     This issue was reported to OpenSSL by Daniel Danner and Rainer Mueller.
     (CVE-2015-0290)
     [Matt Caswell]

  *) Segmentation fault in DTLSv1_listen fix

     The DTLSv1_listen function is intended to be stateless and processes the
     initial ClientHello from many peers. It is common for user code to loop
     over the call to DTLSv1_listen until a valid ClientHello is received with
     an associated cookie. A defect in the implementation of DTLSv1_listen means
     that state is preserved in the SSL object from one invocation to the next
     that can lead to a segmentation fault. Errors processing the initial
     ClientHello can trigger this scenario. An example of such an error could be
     that a DTLS1.0 only client is attempting to connect to a DTLS1.2 only
     server.

     This issue was reported to OpenSSL by Per Allansson.
     (CVE-2015-0207)
     [Matt Caswell]

  *) Segmentation fault in ASN1_TYPE_cmp fix

     The function ASN1_TYPE_cmp will crash with an invalid read if an attempt is
     made to compare ASN.1 boolean types. Since ASN1_TYPE_cmp is used to check
     certificate signature algorithm consistency this can be used to crash any
     certificate verification operation and exploited in a DoS attack. Any
     application which performs certificate verification is vulnerable including
     OpenSSL clients and servers which enable client authentication.
     (CVE-2015-0286)
     [Stephen Henson]

  *) Segmentation fault for invalid PSS parameters fix

     The signature verification routines will crash with a NULL pointer
     dereference if presented with an ASN.1 signature using the RSA PSS
     algorithm and invalid parameters. Since these routines are used to verify
     certificate signature algorithms this can be used to crash any
     certificate verification operation and exploited in a DoS attack. Any
     application which performs certificate verification is vulnerable including
     OpenSSL clients and servers which enable client authentication.

     This issue was was reported to OpenSSL by Brian Carpenter.
     (CVE-2015-0208)
     [Stephen Henson]

  *) ASN.1 structure reuse memory corruption fix

     Reusing a structure in ASN.1 parsing may allow an attacker to cause
     memory corruption via an invalid write. Such reuse is and has been
     strongly discouraged and is believed to be rare.

     Applications that parse structures containing CHOICE or ANY DEFINED BY
     components may be affected. Certificate parsing (d2i_X509 and related
     functions) are however not affected. OpenSSL clients and servers are
     not affected.
     (CVE-2015-0287)
     [Stephen Henson]

  *) PKCS7 NULL pointer dereferences fix

     The PKCS#7 parsing code does not handle missing outer ContentInfo
     correctly. An attacker can craft malformed ASN.1-encoded PKCS#7 blobs with
     missing content and trigger a NULL pointer dereference on parsing.

     Applications that verify PKCS#7 signatures, decrypt PKCS#7 data or
     otherwise parse PKCS#7 structures from untrusted sources are
     affected. OpenSSL clients and servers are not affected.

     This issue was reported to OpenSSL by Michal Zalewski (Google).
     (CVE-2015-0289)
     [Emilia Käsper]

  *) DoS via reachable assert in SSLv2 servers fix

     A malicious client can trigger an OPENSSL_assert (i.e., an abort) in
     servers that both support SSLv2 and enable export cipher suites by sending
     a specially crafted SSLv2 CLIENT-MASTER-KEY message.

     This issue was discovered by Sean Burford (Google) and Emilia Käsper
     (OpenSSL development team).
     (CVE-2015-0293)
     [Emilia Käsper]

  *) Empty CKE with client auth and DHE fix

     If client auth is used then a server can seg fault in the event of a DHE
     ciphersuite being selected and a zero length ClientKeyExchange message
     being sent by the client. This could be exploited in a DoS attack.
     (CVE-2015-1787)
     [Matt Caswell]

  *) Handshake with unseeded PRNG fix

     Under certain conditions an OpenSSL 1.0.2 client can complete a handshake
     with an unseeded PRNG. The conditions are:
     - The client is on a platform where the PRNG has not been seeded
     automatically, and the user has not seeded manually
     - A protocol specific client method version has been used (i.e. not
     SSL_client_methodv23)
     - A ciphersuite is used that does not require additional random data from
     the PRNG beyond the initial ClientHello client random (e.g. PSK-RC4-SHA).

     If the handshake succeeds then the client random that has been used will
     have been generated from a PRNG with insufficient entropy and therefore the
     output may be predictable.

     For example using the following command with an unseeded openssl will
     succeed on an unpatched platform:

     openssl s_client -psk 1a2b3c4d -tls1_2 -cipher PSK-RC4-SHA
     (CVE-2015-0285)
     [Matt Caswell]

  *) Use After Free following d2i_ECPrivatekey error fix

     A malformed EC private key file consumed via the d2i_ECPrivateKey function
     could cause a use after free condition. This, in turn, could cause a double
     free in several private key parsing functions (such as d2i_PrivateKey
     or EVP_PKCS82PKEY) and could lead to a DoS attack or memory corruption
     for applications that receive EC private keys from untrusted
     sources. This scenario is considered rare.

     This issue was discovered by the BoringSSL project and fixed in their
     commit 517073cd4b.
     (CVE-2015-0209)
     [Matt Caswell]

  *) X509_to_X509_REQ NULL pointer deref fix

     The function X509_to_X509_REQ will crash with a NULL pointer dereference if
     the certificate key is invalid. This function is rarely used in practice.

     This issue was discovered by Brian Carpenter.
     (CVE-2015-0288)
     [Stephen Henson]

  *) Removed the export ciphers from the DEFAULT ciphers
     [Kurt Roeckx]

 Changes between 1.0.1l and 1.0.2 [22 Jan 2015]

  *) Facilitate "universal" ARM builds targeting range of ARM ISAs, e.g.
     ARMv5 through ARMv8, as opposite to "locking" it to single one.
     So far those who have to target multiple platforms would compromise
     and argue that binary targeting say ARMv5 would still execute on
     ARMv8. "Universal" build resolves this compromise by providing
     near-optimal performance even on newer platforms.
     [Andy Polyakov]

  *) Accelerated NIST P-256 elliptic curve implementation for x86_64
     (other platforms pending).
     [Shay Gueron & Vlad Krasnov (Intel Corp), Andy Polyakov]

  *) Add support for the SignedCertificateTimestampList certificate and
     OCSP response extensions from RFC6962.
     [Rob Stradling]

  *) Fix ec_GFp_simple_points_make_affine (thus, EC_POINTs_mul etc.)
     for corner cases. (Certain input points at infinity could lead to
     bogus results, with non-infinity inputs mapped to infinity too.)
     [Bodo Moeller]

  *) Initial support for PowerISA 2.0.7, first implemented in POWER8.
     This covers AES, SHA256/512 and GHASH. "Initial" means that most
     common cases are optimized and there still is room for further
     improvements. Vector Permutation AES for Altivec is also added.
     [Andy Polyakov]

  *) Add support for little-endian ppc64 Linux target.
     [Marcelo Cerri (IBM)]

  *) Initial support for AMRv8 ISA crypto extensions. This covers AES,
     SHA1, SHA256 and GHASH. "Initial" means that most common cases
     are optimized and there still is room for further improvements.
     Both 32- and 64-bit modes are supported.
     [Andy Polyakov, Ard Biesheuvel (Linaro)]

  *) Improved ARMv7 NEON support.
     [Andy Polyakov]

  *) Support for SPARC Architecture 2011 crypto extensions, first
     implemented in SPARC T4. This covers AES, DES, Camellia, SHA1,
     SHA256/512, MD5, GHASH and modular exponentiation.
     [Andy Polyakov, David Miller]

  *) Accelerated modular exponentiation for Intel processors, a.k.a.
     RSAZ.
     [Shay Gueron & Vlad Krasnov (Intel Corp)]

  *) Support for new and upcoming Intel processors, including AVX2,
     BMI and SHA ISA extensions. This includes additional "stitched"
     implementations, AESNI-SHA256 and GCM, and multi-buffer support
     for TLS encrypt.

     This work was sponsored by Intel Corp.
     [Andy Polyakov]

  *) Support for DTLS 1.2. This adds two sets of DTLS methods: DTLS_*_method()
     supports both DTLS 1.2 and 1.0 and should use whatever version the peer
     supports and DTLSv1_2_*_method() which supports DTLS 1.2 only.
     [Steve Henson]

  *) Use algorithm specific chains in SSL_CTX_use_certificate_chain_file():
     this fixes a limitation in previous versions of OpenSSL.
     [Steve Henson]

  *) Extended RSA OAEP support via EVP_PKEY API. Options to specify digest,
     MGF1 digest and OAEP label.
     [Steve Henson]

  *) Add EVP support for key wrapping algorithms, to avoid problems with
     existing code the flag EVP_CIPHER_CTX_WRAP_ALLOW has to be set in
     the EVP_CIPHER_CTX or an error is returned. Add AES and DES3 wrap
     algorithms and include tests cases.
     [Steve Henson]

  *) Add functions to allocate and set the fields of an ECDSA_METHOD
     structure.
     [Douglas E. Engert, Steve Henson]

  *) New functions OPENSSL_gmtime_diff and ASN1_TIME_diff to find the
     difference in days and seconds between two tm or ASN1_TIME structures.
     [Steve Henson]

  *) Add -rev test option to s_server to just reverse order of characters
     received by client and send back to server. Also prints an abbreviated
     summary of the connection parameters.
     [Steve Henson]

  *) New option -brief for s_client and s_server to print out a brief summary
     of connection parameters.
     [Steve Henson]

  *) Add callbacks for arbitrary TLS extensions.
     [Trevor Perrin <trevp@trevp.net> and Ben Laurie]

  *) New option -crl_download in several openssl utilities to download CRLs
     from CRLDP extension in certificates.
     [Steve Henson]

  *) New options -CRL and -CRLform for s_client and s_server for CRLs.
     [Steve Henson]

  *) New function X509_CRL_diff to generate a delta CRL from the difference
     of two full CRLs. Add support to "crl" utility.
     [Steve Henson]

  *) New functions to set lookup_crls function and to retrieve
     X509_STORE from X509_STORE_CTX.
     [Steve Henson]

  *) Print out deprecated issuer and subject unique ID fields in
     certificates.
     [Steve Henson]

  *) Extend OCSP I/O functions so they can be used for simple general purpose
     HTTP as well as OCSP. New wrapper function which can be used to download
     CRLs using the OCSP API.
     [Steve Henson]

  *) Delegate command line handling in s_client/s_server to SSL_CONF APIs.
     [Steve Henson]

  *) SSL_CONF* functions. These provide a common framework for application
     configuration using configuration files or command lines.
     [Steve Henson]

  *) SSL/TLS tracing code. This parses out SSL/TLS records using the
     message callback and prints the results. Needs compile time option
     "enable-ssl-trace". New options to s_client and s_server to enable
     tracing.
     [Steve Henson]

  *) New ctrl and macro to retrieve supported points extensions.
     Print out extension in s_server and s_client.
     [Steve Henson]

  *) New functions to retrieve certificate signature and signature
     OID NID.
     [Steve Henson]

  *) Add functions to retrieve and manipulate the raw cipherlist sent by a
     client to OpenSSL.
     [Steve Henson]

  *) New Suite B modes for TLS code. These use and enforce the requirements
     of RFC6460: restrict ciphersuites, only permit Suite B algorithms and
     only use Suite B curves. The Suite B modes can be set by using the
     strings "SUITEB128", "SUITEB192" or "SUITEB128ONLY" for the cipherstring.
     [Steve Henson]

  *) New chain verification flags for Suite B levels of security. Check
     algorithms are acceptable when flags are set in X509_verify_cert.
     [Steve Henson]

  *) Make tls1_check_chain return a set of flags indicating checks passed
     by a certificate chain. Add additional tests to handle client
     certificates: checks for matching certificate type and issuer name
     comparison.
     [Steve Henson]

  *) If an attempt is made to use a signature algorithm not in the peer
     preference list abort the handshake. If client has no suitable
     signature algorithms in response to a certificate request do not
     use the certificate.
     [Steve Henson]

  *) If server EC tmp key is not in client preference list abort handshake.
     [Steve Henson]

  *) Add support for certificate stores in CERT structure. This makes it
     possible to have different stores per SSL structure or one store in
     the parent SSL_CTX. Include distinct stores for certificate chain
     verification and chain building. New ctrl SSL_CTRL_BUILD_CERT_CHAIN
     to build and store a certificate chain in CERT structure: returning
     an error if the chain cannot be built: this will allow applications
     to test if a chain is correctly configured.

     Note: if the CERT based stores are not set then the parent SSL_CTX
     store is used to retain compatibility with existing behaviour.

     [Steve Henson]

  *) New function ssl_set_client_disabled to set a ciphersuite disabled
     mask based on the current session, check mask when sending client
     hello and checking the requested ciphersuite.
     [Steve Henson]

  *) New ctrls to retrieve and set certificate types in a certificate
     request message. Print out received values in s_client. If certificate
     types is not set with custom values set sensible values based on
     supported signature algorithms.
     [Steve Henson]

  *) Support for distinct client and server supported signature algorithms.
     [Steve Henson]

  *) Add certificate callback. If set this is called whenever a certificate
     is required by client or server. An application can decide which
     certificate chain to present based on arbitrary criteria: for example
     supported signature algorithms. Add very simple example to s_server.
     This fixes many of the problems and restrictions of the existing client
     certificate callback: for example you can now clear an existing
     certificate and specify the whole chain.
     [Steve Henson]

  *) Add new "valid_flags" field to CERT_PKEY structure which determines what
     the certificate can be used for (if anything). Set valid_flags field 
     in new tls1_check_chain function. Simplify ssl_set_cert_masks which used
     to have similar checks in it.

     Add new "cert_flags" field to CERT structure and include a "strict mode".
     This enforces some TLS certificate requirements (such as only permitting
     certificate signature algorithms contained in the supported algorithms
     extension) which some implementations ignore: this option should be used
     with caution as it could cause interoperability issues.
     [Steve Henson]

  *) Update and tidy signature algorithm extension processing. Work out
     shared signature algorithms based on preferences and peer algorithms
     and print them out in s_client and s_server. Abort handshake if no
     shared signature algorithms.
     [Steve Henson]

  *) Add new functions to allow customised supported signature algorithms
     for SSL and SSL_CTX structures. Add options to s_client and s_server
     to support them.
     [Steve Henson]

  *) New function SSL_certs_clear() to delete all references to certificates
     from an SSL structure. Before this once a certificate had been added
     it couldn't be removed.
     [Steve Henson]

  *) Integrate hostname, email address and IP address checking with certificate
     verification. New verify options supporting checking in openssl utility.
     [Steve Henson]

  *) Fixes and wildcard matching support to hostname and email checking
     functions. Add manual page.
     [Florian Weimer (Red Hat Product Security Team)]

  *) New functions to check a hostname email or IP address against a
     certificate. Add options x509 utility to print results of checks against
     a certificate.
     [Steve Henson]

  *) Fix OCSP checking.
     [Rob Stradling <rob.stradling@comodo.com> and Ben Laurie]

  *) Initial experimental support for explicitly trusted non-root CAs. 
     OpenSSL still tries to build a complete chain to a root but if an
     intermediate CA has a trust setting included that is used. The first
     setting is used: whether to trust (e.g., -addtrust option to the x509
     utility) or reject.
     [Steve Henson]

  *) Add -trusted_first option which attempts to find certificates in the
     trusted store even if an untrusted chain is also supplied.
     [Steve Henson]

  *) MIPS assembly pack updates: support for MIPS32r2 and SmartMIPS ASE,
     platform support for Linux and Android.
     [Andy Polyakov]

  *) Support for linux-x32, ILP32 environment in x86_64 framework.
     [Andy Polyakov]

  *) Experimental multi-implementation support for FIPS capable OpenSSL.
     When in FIPS mode the approved implementations are used as normal,
     when not in FIPS mode the internal unapproved versions are used instead.
     This means that the FIPS capable OpenSSL isn't forced to use the
     (often lower performance) FIPS implementations outside FIPS mode.
     [Steve Henson]

  *) Transparently support X9.42 DH parameters when calling
     PEM_read_bio_DHparameters. This means existing applications can handle
     the new parameter format automatically.
     [Steve Henson]

  *) Initial experimental support for X9.42 DH parameter format: mainly
     to support use of 'q' parameter for RFC5114 parameters.
     [Steve Henson]

  *) Add DH parameters from RFC5114 including test data to dhtest.
     [Steve Henson]

  *) Support for automatic EC temporary key parameter selection. If enabled
     the most preferred EC parameters are automatically used instead of
     hardcoded fixed parameters. Now a server just has to call:
     SSL_CTX_set_ecdh_auto(ctx, 1) and the server will automatically
     support ECDH and use the most appropriate parameters.
     [Steve Henson]

  *) Enhance and tidy EC curve and point format TLS extension code. Use
     static structures instead of allocation if default values are used.
     New ctrls to set curves we wish to support and to retrieve shared curves.
     Print out shared curves in s_server. New options to s_server and s_client
     to set list of supported curves.
     [Steve Henson]

  *) New ctrls to retrieve supported signature algorithms and 
     supported curve values as an array of NIDs. Extend openssl utility
     to print out received values.
     [Steve Henson]

  *) Add new APIs EC_curve_nist2nid and EC_curve_nid2nist which convert
     between NIDs and the more common NIST names such as "P-256". Enhance
     ecparam utility and ECC method to recognise the NIST names for curves.
     [Steve Henson]

  *) Enhance SSL/TLS certificate chain handling to support different
     chains for each certificate instead of one chain in the parent SSL_CTX.
     [Steve Henson]

  *) Support for fixed DH ciphersuite client authentication: where both
     server and client use DH certificates with common parameters.
     [Steve Henson]

  *) Support for fixed DH ciphersuites: those requiring DH server
     certificates.
     [Steve Henson]

  *) New function i2d_re_X509_tbs for re-encoding the TBS portion of
     the certificate.
     Note: Related 1.0.2-beta specific macros X509_get_cert_info,
     X509_CINF_set_modified, X509_CINF_get_issuer, X509_CINF_get_extensions and
     X509_CINF_get_signature were reverted post internal team review.

 Changes between 1.0.1k and 1.0.1l [15 Jan 2015]

  *) Build fixes for the Windows and OpenVMS platforms
     [Matt Caswell and Richard Levitte]

 Changes between 1.0.1j and 1.0.1k [8 Jan 2015]

  *) Fix DTLS segmentation fault in dtls1_get_record. A carefully crafted DTLS
     message can cause a segmentation fault in OpenSSL due to a NULL pointer
     dereference. This could lead to a Denial Of Service attack. Thanks to
     Markus Stenberg of Cisco Systems, Inc. for reporting this issue.
     (CVE-2014-3571)
     [Steve Henson]

  *) Fix DTLS memory leak in dtls1_buffer_record. A memory leak can occur in the
     dtls1_buffer_record function under certain conditions. In particular this
     could occur if an attacker sent repeated DTLS records with the same
     sequence number but for the next epoch. The memory leak could be exploited
     by an attacker in a Denial of Service attack through memory exhaustion.
     Thanks to Chris Mueller for reporting this issue.
     (CVE-2015-0206)
     [Matt Caswell]

  *) Fix issue where no-ssl3 configuration sets method to NULL. When openssl is
     built with the no-ssl3 option and a SSL v3 ClientHello is received the ssl
     method would be set to NULL which could later result in a NULL pointer
     dereference. Thanks to Frank Schmirler for reporting this issue.
     (CVE-2014-3569)
     [Kurt Roeckx]

  *) Abort handshake if server key exchange message is omitted for ephemeral
     ECDH ciphersuites.

     Thanks to Karthikeyan Bhargavan of the PROSECCO team at INRIA for
     reporting this issue.
     (CVE-2014-3572)
     [Steve Henson]

  *) Remove non-export ephemeral RSA code on client and server. This code
     violated the TLS standard by allowing the use of temporary RSA keys in
     non-export ciphersuites and could be used by a server to effectively
     downgrade the RSA key length used to a value smaller than the server
     certificate. Thanks for Karthikeyan Bhargavan of the PROSECCO team at
     INRIA or reporting this issue.
     (CVE-2015-0204)
     [Steve Henson]

  *) Fixed issue where DH client certificates are accepted without verification.
     An OpenSSL server will accept a DH certificate for client authentication
     without the certificate verify message. This effectively allows a client to
     authenticate without the use of a private key. This only affects servers
     which trust a client certificate authority which issues certificates
     containing DH keys: these are extremely rare and hardly ever encountered.
     Thanks for Karthikeyan Bhargavan of the PROSECCO team at INRIA or reporting
     this issue.
     (CVE-2015-0205)
     [Steve Henson]

  *) Ensure that the session ID context of an SSL is updated when its
     SSL_CTX is updated via SSL_set_SSL_CTX.

     The session ID context is typically set from the parent SSL_CTX,
     and can vary with the CTX.
     [Adam Langley]

  *) Fix various certificate fingerprint issues.

     By using non-DER or invalid encodings outside the signed portion of a
     certificate the fingerprint can be changed without breaking the signature.
     Although no details of the signed portion of the certificate can be changed
     this can cause problems with some applications: e.g. those using the
     certificate fingerprint for blacklists.

     1. Reject signatures with non zero unused bits.

     If the BIT STRING containing the signature has non zero unused bits reject
     the signature. All current signature algorithms require zero unused bits.

     2. Check certificate algorithm consistency.

     Check the AlgorithmIdentifier inside TBS matches the one in the
     certificate signature. NB: this will result in signature failure
     errors for some broken certificates.

     Thanks to Konrad Kraszewski from Google for reporting this issue.

     3. Check DSA/ECDSA signatures use DER.

     Re-encode DSA/ECDSA signatures and compare with the original received
     signature. Return an error if there is a mismatch.

     This will reject various cases including garbage after signature
     (thanks to Antti Karjalainen and Tuomo Untinen from the Codenomicon CROSS
     program for discovering this case) and use of BER or invalid ASN.1 INTEGERs
     (negative or with leading zeroes).

     Further analysis was conducted and fixes were developed by Stephen Henson
     of the OpenSSL core team.

     (CVE-2014-8275)
     [Steve Henson]

   *) Correct Bignum squaring. Bignum squaring (BN_sqr) may produce incorrect
      results on some platforms, including x86_64. This bug occurs at random
      with a very low probability, and is not known to be exploitable in any
      way, though its exact impact is difficult to determine. Thanks to Pieter
      Wuille (Blockstream) who reported this issue and also suggested an initial
      fix. Further analysis was conducted by the OpenSSL development team and
      Adam Langley of Google. The final fix was developed by Andy Polyakov of
      the OpenSSL core team.
      (CVE-2014-3570)
      [Andy Polyakov]

   *) Do not resume sessions on the server if the negotiated protocol
      version does not match the session's version. Resuming with a different
      version, while not strictly forbidden by the RFC, is of questionable
      sanity and breaks all known clients.
      [David Benjamin, Emilia Käsper]

   *) Tighten handling of the ChangeCipherSpec (CCS) message: reject
      early CCS messages during renegotiation. (Note that because
      renegotiation is encrypted, this early CCS was not exploitable.)
      [Emilia Käsper]

   *) Tighten client-side session ticket handling during renegotiation:
      ensure that the client only accepts a session ticket if the server sends
      the extension anew in the ServerHello. Previously, a TLS client would
      reuse the old extension state and thus accept a session ticket if one was
      announced in the initial ServerHello.

      Similarly, ensure that the client requires a session ticket if one
      was advertised in the ServerHello. Previously, a TLS client would
      ignore a missing NewSessionTicket message.
      [Emilia Käsper]

 Changes between 1.0.1i and 1.0.1j [15 Oct 2014]

  *) SRTP Memory Leak.

     A flaw in the DTLS SRTP extension parsing code allows an attacker, who
     sends a carefully crafted handshake message, to cause OpenSSL to fail
     to free up to 64k of memory causing a memory leak. This could be
     exploited in a Denial Of Service attack. This issue affects OpenSSL
     1.0.1 server implementations for both SSL/TLS and DTLS regardless of
     whether SRTP is used or configured. Implementations of OpenSSL that
     have been compiled with OPENSSL_NO_SRTP defined are not affected.

     The fix was developed by the OpenSSL team.
     (CVE-2014-3513)
     [OpenSSL team]

  *) Session Ticket Memory Leak.

     When an OpenSSL SSL/TLS/DTLS server receives a session ticket the
     integrity of that ticket is first verified. In the event of a session
     ticket integrity check failing, OpenSSL will fail to free memory
     causing a memory leak. By sending a large number of invalid session
     tickets an attacker could exploit this issue in a Denial Of Service
     attack.
     (CVE-2014-3567)
     [Steve Henson]

  *) Build option no-ssl3 is incomplete.

     When OpenSSL is configured with "no-ssl3" as a build option, servers
     could accept and complete a SSL 3.0 handshake, and clients could be
     configured to send them.
     (CVE-2014-3568)
     [Akamai and the OpenSSL team]

  *) Add support for TLS_FALLBACK_SCSV.
     Client applications doing fallback retries should call
     SSL_set_mode(s, SSL_MODE_SEND_FALLBACK_SCSV).
     (CVE-2014-3566)
     [Adam Langley, Bodo Moeller]

  *) Add additional DigestInfo checks.
 
     Re-encode DigestInto in DER and check against the original when
     verifying RSA signature: this will reject any improperly encoded
     DigestInfo structures.

     Note: this is a precautionary measure and no attacks are currently known.

     [Steve Henson]

 Changes between 1.0.1h and 1.0.1i [6 Aug 2014]

  *) Fix SRP buffer overrun vulnerability. Invalid parameters passed to the
     SRP code can be overrun an internal buffer. Add sanity check that
     g, A, B < N to SRP code.

     Thanks to Sean Devlin and Watson Ladd of Cryptography Services, NCC
     Group for discovering this issue.
     (CVE-2014-3512)
     [Steve Henson]

  *) A flaw in the OpenSSL SSL/TLS server code causes the server to negotiate
     TLS 1.0 instead of higher protocol versions when the ClientHello message
     is badly fragmented. This allows a man-in-the-middle attacker to force a
     downgrade to TLS 1.0 even if both the server and the client support a
     higher protocol version, by modifying the client's TLS records.

     Thanks to David Benjamin and Adam Langley (Google) for discovering and
     researching this issue.
     (CVE-2014-3511)
     [David Benjamin]

  *) OpenSSL DTLS clients enabling anonymous (EC)DH ciphersuites are subject
     to a denial of service attack. A malicious server can crash the client
     with a null pointer dereference (read) by specifying an anonymous (EC)DH
     ciphersuite and sending carefully crafted handshake messages.

     Thanks to Felix Gröbert (Google) for discovering and researching this
     issue.
     (CVE-2014-3510)
     [Emilia Käsper]

  *) By sending carefully crafted DTLS packets an attacker could cause openssl
     to leak memory. This can be exploited through a Denial of Service attack.
     Thanks to Adam Langley for discovering and researching this issue.
     (CVE-2014-3507)
     [Adam Langley]

  *) An attacker can force openssl to consume large amounts of memory whilst
     processing DTLS handshake messages. This can be exploited through a
     Denial of Service attack.
     Thanks to Adam Langley for discovering and researching this issue.
     (CVE-2014-3506)
     [Adam Langley]

  *) An attacker can force an error condition which causes openssl to crash
     whilst processing DTLS packets due to memory being freed twice. This
     can be exploited through a Denial of Service attack.
     Thanks to Adam Langley and Wan-Teh Chang for discovering and researching
     this issue.
     (CVE-2014-3505)
     [Adam Langley]

  *) If a multithreaded client connects to a malicious server using a resumed
     session and the server sends an ec point format extension it could write
     up to 255 bytes to freed memory.

     Thanks to Gabor Tyukasz (LogMeIn Inc) for discovering and researching this
     issue.
     (CVE-2014-3509)
     [Gabor Tyukasz]

  *) A malicious server can crash an OpenSSL client with a null pointer
     dereference (read) by specifying an SRP ciphersuite even though it was not
     properly negotiated with the client. This can be exploited through a
     Denial of Service attack.

     Thanks to Joonas Kuorilehto and Riku Hietamäki (Codenomicon) for
     discovering and researching this issue.
     (CVE-2014-5139)
     [Steve Henson]

  *) A flaw in OBJ_obj2txt may cause pretty printing functions such as
     X509_name_oneline, X509_name_print_ex et al. to leak some information
     from the stack. Applications may be affected if they echo pretty printing
     output to the attacker.

     Thanks to Ivan Fratric (Google) for discovering this issue.
     (CVE-2014-3508)
     [Emilia Käsper, and Steve Henson]

  *) Fix ec_GFp_simple_points_make_affine (thus, EC_POINTs_mul etc.)
     for corner cases. (Certain input points at infinity could lead to
     bogus results, with non-infinity inputs mapped to infinity too.)
     [Bodo Moeller]

 Changes between 1.0.1g and 1.0.1h [5 Jun 2014]

  *) Fix for SSL/TLS MITM flaw. An attacker using a carefully crafted
     handshake can force the use of weak keying material in OpenSSL
     SSL/TLS clients and servers.

     Thanks to KIKUCHI Masashi (Lepidum Co. Ltd.) for discovering and
     researching this issue. (CVE-2014-0224)
     [KIKUCHI Masashi, Steve Henson]

  *) Fix DTLS recursion flaw. By sending an invalid DTLS handshake to an
     OpenSSL DTLS client the code can be made to recurse eventually crashing
     in a DoS attack.

     Thanks to Imre Rad (Search-Lab Ltd.) for discovering this issue.
     (CVE-2014-0221)
     [Imre Rad, Steve Henson]

  *) Fix DTLS invalid fragment vulnerability. A buffer overrun attack can
     be triggered by sending invalid DTLS fragments to an OpenSSL DTLS
     client or server. This is potentially exploitable to run arbitrary
     code on a vulnerable client or server.

     Thanks to Jüri Aedla for reporting this issue. (CVE-2014-0195)
     [Jüri Aedla, Steve Henson]

  *) Fix bug in TLS code where clients enable anonymous ECDH ciphersuites
     are subject to a denial of service attack.

     Thanks to Felix Gröbert and Ivan Fratric at Google for discovering
     this issue. (CVE-2014-3470)
     [Felix Gröbert, Ivan Fratric, Steve Henson]

  *) Harmonize version and its documentation. -f flag is used to display
     compilation flags.
     [mancha <mancha1@zoho.com>]

  *) Fix eckey_priv_encode so it immediately returns an error upon a failure
     in i2d_ECPrivateKey.
     [mancha <mancha1@zoho.com>]

  *) Fix some double frees. These are not thought to be exploitable.
     [mancha <mancha1@zoho.com>]

 Changes between 1.0.1f and 1.0.1g [7 Apr 2014]

  *) A missing bounds check in the handling of the TLS heartbeat extension
     can be used to reveal up to 64k of memory to a connected client or
     server.

     Thanks for Neel Mehta of Google Security for discovering this bug and to
     Adam Langley <agl@chromium.org> and Bodo Moeller <bmoeller@acm.org> for
     preparing the fix (CVE-2014-0160)
     [Adam Langley, Bodo Moeller]

  *) Fix for the attack described in the paper "Recovering OpenSSL
     ECDSA Nonces Using the FLUSH+RELOAD Cache Side-channel Attack"
     by Yuval Yarom and Naomi Benger. Details can be obtained from:
     http://eprint.iacr.org/2014/140

     Thanks to Yuval Yarom and Naomi Benger for discovering this
     flaw and to Yuval Yarom for supplying a fix (CVE-2014-0076)
     [Yuval Yarom and Naomi Benger]

  *) TLS pad extension: draft-agl-tls-padding-03

     Workaround for the "TLS hang bug" (see FAQ and PR#2771): if the
     TLS client Hello record length value would otherwise be > 255 and
     less that 512 pad with a dummy extension containing zeroes so it
     is at least 512 bytes long.

     [Adam Langley, Steve Henson]

 Changes between 1.0.1e and 1.0.1f [6 Jan 2014]

  *) Fix for TLS record tampering bug. A carefully crafted invalid 
     handshake could crash OpenSSL with a NULL pointer exception.
     Thanks to Anton Johansson for reporting this issues.
     (CVE-2013-4353)

  *) Keep original DTLS digest and encryption contexts in retransmission
     structures so we can use the previous session parameters if they need
     to be resent. (CVE-2013-6450)
     [Steve Henson]

  *) Add option SSL_OP_SAFARI_ECDHE_ECDSA_BUG (part of SSL_OP_ALL) which
     avoids preferring ECDHE-ECDSA ciphers when the client appears to be
     Safari on OS X.  Safari on OS X 10.8..10.8.3 advertises support for
     several ECDHE-ECDSA ciphers, but fails to negotiate them.  The bug
     is fixed in OS X 10.8.4, but Apple have ruled out both hot fixing
     10.8..10.8.3 and forcing users to upgrade to 10.8.4 or newer.
     [Rob Stradling, Adam Langley]

 Changes between 1.0.1d and 1.0.1e [11 Feb 2013]

  *) Correct fix for CVE-2013-0169. The original didn't work on AES-NI
     supporting platforms or when small records were transferred.
     [Andy Polyakov, Steve Henson]

 Changes between 1.0.1c and 1.0.1d [5 Feb 2013]

  *) Make the decoding of SSLv3, TLS and DTLS CBC records constant time.

     This addresses the flaw in CBC record processing discovered by 
     Nadhem Alfardan and Kenny Paterson. Details of this attack can be found
     at: http://www.isg.rhul.ac.uk/tls/     

     Thanks go to Nadhem Alfardan and Kenny Paterson of the Information
     Security Group at Royal Holloway, University of London
     (www.isg.rhul.ac.uk) for discovering this flaw and Adam Langley and
     Emilia Käsper for the initial patch.
     (CVE-2013-0169)
     [Emilia Käsper, Adam Langley, Ben Laurie, Andy Polyakov, Steve Henson]

  *) Fix flaw in AESNI handling of TLS 1.2 and 1.1 records for CBC mode
     ciphersuites which can be exploited in a denial of service attack.
     Thanks go to and to Adam Langley <agl@chromium.org> for discovering
     and detecting this bug and to Wolfgang Ettlinger
     <wolfgang.ettlinger@gmail.com> for independently discovering this issue.
     (CVE-2012-2686)
     [Adam Langley]

  *) Return an error when checking OCSP signatures when key is NULL.
     This fixes a DoS attack. (CVE-2013-0166)
     [Steve Henson]

  *) Make openssl verify return errors.
     [Chris Palmer <palmer@google.com> and Ben Laurie]

  *) Call OCSP Stapling callback after ciphersuite has been chosen, so
     the right response is stapled. Also change SSL_get_certificate()
     so it returns the certificate actually sent.
     See http://rt.openssl.org/Ticket/Display.html?id=2836.
     [Rob Stradling <rob.stradling@comodo.com>]

  *) Fix possible deadlock when decoding public keys.
     [Steve Henson]

  *) Don't use TLS 1.0 record version number in initial client hello
     if renegotiating.
     [Steve Henson]

 Changes between 1.0.1b and 1.0.1c [10 May 2012]

  *) Sanity check record length before skipping explicit IV in TLS
     1.2, 1.1 and DTLS to fix DoS attack.

     Thanks to Codenomicon for discovering this issue using Fuzz-o-Matic
     fuzzing as a service testing platform.
     (CVE-2012-2333)
     [Steve Henson]

  *) Initialise tkeylen properly when encrypting CMS messages.
     Thanks to Solar Designer of Openwall for reporting this issue.
     [Steve Henson]

  *) In FIPS mode don't try to use composite ciphers as they are not
     approved.
     [Steve Henson]

 Changes between 1.0.1a and 1.0.1b [26 Apr 2012]

  *) OpenSSL 1.0.0 sets SSL_OP_ALL to 0x80000FFFL and OpenSSL 1.0.1 and
     1.0.1a set SSL_OP_NO_TLSv1_1 to 0x00000400L which would unfortunately
     mean any application compiled against OpenSSL 1.0.0 headers setting
     SSL_OP_ALL would also set SSL_OP_NO_TLSv1_1, unintentionally disablng
     TLS 1.1 also. Fix this by changing the value of SSL_OP_NO_TLSv1_1 to
     0x10000000L Any application which was previously compiled against
     OpenSSL 1.0.1 or 1.0.1a headers and which cares about SSL_OP_NO_TLSv1_1
     will need to be recompiled as a result. Letting be results in
     inability to disable specifically TLS 1.1 and in client context,
     in unlike event, limit maximum offered version to TLS 1.0 [see below].
     [Steve Henson]

  *) In order to ensure interoperabilty SSL_OP_NO_protocolX does not
     disable just protocol X, but all protocols above X *if* there are
     protocols *below* X still enabled. In more practical terms it means
     that if application wants to disable TLS1.0 in favor of TLS1.1 and
     above, it's not sufficient to pass SSL_OP_NO_TLSv1, one has to pass
     SSL_OP_NO_TLSv1|SSL_OP_NO_SSLv3|SSL_OP_NO_SSLv2. This applies to
     client side.
     [Andy Polyakov]

 Changes between 1.0.1 and 1.0.1a [19 Apr 2012]

  *) Check for potentially exploitable overflows in asn1_d2i_read_bio
     BUF_mem_grow and BUF_mem_grow_clean. Refuse attempts to shrink buffer
     in CRYPTO_realloc_clean.

     Thanks to Tavis Ormandy, Google Security Team, for discovering this
     issue and to Adam Langley <agl@chromium.org> for fixing it.
     (CVE-2012-2110)
     [Adam Langley (Google), Tavis Ormandy, Google Security Team]

  *) Don't allow TLS 1.2 SHA-256 ciphersuites in TLS 1.0, 1.1 connections.
     [Adam Langley]

  *) Workarounds for some broken servers that "hang" if a client hello
     record length exceeds 255 bytes.

     1. Do not use record version number > TLS 1.0 in initial client
        hello: some (but not all) hanging servers will now work.
     2. If we set OPENSSL_MAX_TLS1_2_CIPHER_LENGTH this will truncate
        the number of ciphers sent in the client hello. This should be
        set to an even number, such as 50, for example by passing:
        -DOPENSSL_MAX_TLS1_2_CIPHER_LENGTH=50 to config or Configure.
        Most broken servers should now work.
     3. If all else fails setting OPENSSL_NO_TLS1_2_CLIENT will disable
        TLS 1.2 client support entirely.
     [Steve Henson]

  *) Fix SEGV in Vector Permutation AES module observed in OpenSSH.
     [Andy Polyakov]

 Changes between 1.0.0h and 1.0.1  [14 Mar 2012]

  *) Add compatibility with old MDC2 signatures which use an ASN1 OCTET
     STRING form instead of a DigestInfo.
     [Steve Henson]

  *) The format used for MDC2 RSA signatures is inconsistent between EVP
     and the RSA_sign/RSA_verify functions. This was made more apparent when
     OpenSSL used RSA_sign/RSA_verify for some RSA signatures in particular
     those which went through EVP_PKEY_METHOD in 1.0.0 and later. Detect 
     the correct format in RSA_verify so both forms transparently work.
     [Steve Henson]

  *) Some servers which support TLS 1.0 can choke if we initially indicate
     support for TLS 1.2 and later renegotiate using TLS 1.0 in the RSA
     encrypted premaster secret. As a workaround use the maximum permitted
     client version in client hello, this should keep such servers happy
     and still work with previous versions of OpenSSL.
     [Steve Henson]

  *) Add support for TLS/DTLS heartbeats.
     [Robin Seggelmann <seggelmann@fh-muenster.de>]

  *) Add support for SCTP.
     [Robin Seggelmann <seggelmann@fh-muenster.de>]

  *) Improved PRNG seeding for VOS.
     [Paul Green <Paul.Green@stratus.com>]

  *) Extensive assembler packs updates, most notably:

        - x86[_64]:     AES-NI, PCLMULQDQ, RDRAND support;
        - x86[_64]:     SSSE3 support (SHA1, vector-permutation AES);
        - x86_64:       bit-sliced AES implementation;
        - ARM:          NEON support, contemporary platforms optimizations;
        - s390x:        z196 support;
        - *:            GHASH and GF(2^m) multiplication implementations;

     [Andy Polyakov]

  *) Make TLS-SRP code conformant with RFC 5054 API cleanup
     (removal of unnecessary code)
     [Peter Sylvester <peter.sylvester@edelweb.fr>]

  *) Add TLS key material exporter from RFC 5705.
     [Eric Rescorla]

  *) Add DTLS-SRTP negotiation from RFC 5764.
     [Eric Rescorla]

  *) Add Next Protocol Negotiation,
     http://tools.ietf.org/html/draft-agl-tls-nextprotoneg-00. Can be
     disabled with a no-npn flag to config or Configure. Code donated
     by Google.
     [Adam Langley <agl@google.com> and Ben Laurie]

  *) Add optional 64-bit optimized implementations of elliptic curves NIST-P224,
     NIST-P256, NIST-P521, with constant-time single point multiplication on
     typical inputs. Compiler support for the nonstandard type __uint128_t is
     required to use this (present in gcc 4.4 and later, for 64-bit builds).
     Code made available under Apache License version 2.0.

     Specify "enable-ec_nistp_64_gcc_128" on the Configure (or config) command
     line to include this in your build of OpenSSL, and run "make depend" (or
     "make update"). This enables the following EC_METHODs:

         EC_GFp_nistp224_method()
         EC_GFp_nistp256_method()
         EC_GFp_nistp521_method()

     EC_GROUP_new_by_curve_name() will automatically use these (while
     EC_GROUP_new_curve_GFp() currently prefers the more flexible
     implementations).
     [Emilia Käsper, Adam Langley, Bodo Moeller (Google)]

  *) Use type ossl_ssize_t instad of ssize_t which isn't available on
     all platforms. Move ssize_t definition from e_os.h to the public
     header file e_os2.h as it now appears in public header file cms.h
     [Steve Henson]

  *) New -sigopt option to the ca, req and x509 utilities. Additional
     signature parameters can be passed using this option and in
     particular PSS. 
     [Steve Henson]

  *) Add RSA PSS signing function. This will generate and set the
     appropriate AlgorithmIdentifiers for PSS based on those in the
     corresponding EVP_MD_CTX structure. No application support yet.
     [Steve Henson]

  *) Support for companion algorithm specific ASN1 signing routines.
     New function ASN1_item_sign_ctx() signs a pre-initialised
     EVP_MD_CTX structure and sets AlgorithmIdentifiers based on
     the appropriate parameters.
     [Steve Henson]

  *) Add new algorithm specific ASN1 verification initialisation function
     to EVP_PKEY_ASN1_METHOD: this is not in EVP_PKEY_METHOD since the ASN1
     handling will be the same no matter what EVP_PKEY_METHOD is used.
     Add a PSS handler to support verification of PSS signatures: checked
     against a number of sample certificates.
     [Steve Henson]

  *) Add signature printing for PSS. Add PSS OIDs.
     [Steve Henson, Martin Kaiser <lists@kaiser.cx>]

  *) Add algorithm specific signature printing. An individual ASN1 method
     can now print out signatures instead of the standard hex dump. 

     More complex signatures (e.g. PSS) can print out more meaningful
     information. Include DSA version that prints out the signature
     parameters r, s.
     [Steve Henson]

  *) Password based recipient info support for CMS library: implementing
     RFC3211.
     [Steve Henson]

  *) Split password based encryption into PBES2 and PBKDF2 functions. This
     neatly separates the code into cipher and PBE sections and is required
     for some algorithms that split PBES2 into separate pieces (such as
     password based CMS).
     [Steve Henson]

  *) Session-handling fixes:
     - Fix handling of connections that are resuming with a session ID,
       but also support Session Tickets.
     - Fix a bug that suppressed issuing of a new ticket if the client
       presented a ticket with an expired session.
     - Try to set the ticket lifetime hint to something reasonable.
     - Make tickets shorter by excluding irrelevant information.
     - On the client side, don't ignore renewed tickets.
     [Adam Langley, Bodo Moeller (Google)]

  *) Fix PSK session representation.
     [Bodo Moeller]

  *) Add RC4-MD5 and AESNI-SHA1 "stitched" implementations.

     This work was sponsored by Intel.
     [Andy Polyakov]

  *) Add GCM support to TLS library. Some custom code is needed to split
     the IV between the fixed (from PRF) and explicit (from TLS record)
     portions. This adds all GCM ciphersuites supported by RFC5288 and 
     RFC5289. Generalise some AES* cipherstrings to include GCM and
     add a special AESGCM string for GCM only.
     [Steve Henson]

  *) Expand range of ctrls for AES GCM. Permit setting invocation
     field on decrypt and retrieval of invocation field only on encrypt.
     [Steve Henson]

  *) Add HMAC ECC ciphersuites from RFC5289. Include SHA384 PRF support.
     As required by RFC5289 these ciphersuites cannot be used if for
     versions of TLS earlier than 1.2.
     [Steve Henson]

  *) For FIPS capable OpenSSL interpret a NULL default public key method
     as unset and return the appropriate default but do *not* set the default.
     This means we can return the appropriate method in applications that
     switch between FIPS and non-FIPS modes.
     [Steve Henson]

  *) Redirect HMAC and CMAC operations to FIPS module in FIPS mode. If an
     ENGINE is used then we cannot handle that in the FIPS module so we
     keep original code iff non-FIPS operations are allowed.
     [Steve Henson]

  *) Add -attime option to openssl utilities.
     [Peter Eckersley <pde@eff.org>, Ben Laurie and Steve Henson]

  *) Redirect DSA and DH operations to FIPS module in FIPS mode.
     [Steve Henson]

  *) Redirect ECDSA and ECDH operations to FIPS module in FIPS mode. Also use
     FIPS EC methods unconditionally for now.
     [Steve Henson]

  *) New build option no-ec2m to disable characteristic 2 code.
     [Steve Henson]

  *) Backport libcrypto audit of return value checking from 1.1.0-dev; not
     all cases can be covered as some introduce binary incompatibilities.
     [Steve Henson]

  *) Redirect RSA operations to FIPS module including keygen,
     encrypt, decrypt, sign and verify. Block use of non FIPS RSA methods.
     [Steve Henson]

  *) Add similar low level API blocking to ciphers.
     [Steve Henson]

  *) Low level digest APIs are not approved in FIPS mode: any attempt
     to use these will cause a fatal error. Applications that *really* want
     to use them can use the private_* version instead.
     [Steve Henson]

  *) Redirect cipher operations to FIPS module for FIPS builds. 
     [Steve Henson]

  *) Redirect digest operations to FIPS module for FIPS builds. 
     [Steve Henson]

  *) Update build system to add "fips" flag which will link in fipscanister.o
     for static and shared library builds embedding a signature if needed.
     [Steve Henson]

  *) Output TLS supported curves in preference order instead of numerical
     order. This is currently hardcoded for the highest order curves first.
     This should be configurable so applications can judge speed vs strength.
     [Steve Henson]

  *) Add TLS v1.2 server support for client authentication. 
     [Steve Henson]

  *) Add support for FIPS mode in ssl library: disable SSLv3, non-FIPS ciphers
     and enable MD5.
     [Steve Henson]

  *) Functions FIPS_mode_set() and FIPS_mode() which call the underlying
     FIPS modules versions.
     [Steve Henson]

  *) Add TLS v1.2 client side support for client authentication. Keep cache
     of handshake records longer as we don't know the hash algorithm to use
     until after the certificate request message is received.
     [Steve Henson]

  *) Initial TLS v1.2 client support. Add a default signature algorithms
     extension including all the algorithms we support. Parse new signature
     format in client key exchange. Relax some ECC signing restrictions for
     TLS v1.2 as indicated in RFC5246.
     [Steve Henson]

  *) Add server support for TLS v1.2 signature algorithms extension. Switch
     to new signature format when needed using client digest preference.
     All server ciphersuites should now work correctly in TLS v1.2. No client
     support yet and no support for client certificates.
     [Steve Henson]

  *) Initial TLS v1.2 support. Add new SHA256 digest to ssl code, switch
     to SHA256 for PRF when using TLS v1.2 and later. Add new SHA256 based
     ciphersuites. At present only RSA key exchange ciphersuites work with
     TLS v1.2. Add new option for TLS v1.2 replacing the old and obsolete
     SSL_OP_PKCS1_CHECK flags with SSL_OP_NO_TLSv1_2. New TLSv1.2 methods
     and version checking.
     [Steve Henson]

  *) New option OPENSSL_NO_SSL_INTERN. If an application can be compiled
     with this defined it will not be affected by any changes to ssl internal
     structures. Add several utility functions to allow openssl application
     to work with OPENSSL_NO_SSL_INTERN defined.
     [Steve Henson]

  *) Add SRP support.
     [Tom Wu <tjw@cs.stanford.edu> and Ben Laurie]

  *) Add functions to copy EVP_PKEY_METHOD and retrieve flags and id.
     [Steve Henson]

  *) Permit abbreviated handshakes when renegotiating using the function
     SSL_renegotiate_abbreviated().
     [Robin Seggelmann <seggelmann@fh-muenster.de>]

  *) Add call to ENGINE_register_all_complete() to
     ENGINE_load_builtin_engines(), so some implementations get used
     automatically instead of needing explicit application support.
     [Steve Henson]

  *) Add support for TLS key exporter as described in RFC5705.
     [Robin Seggelmann <seggelmann@fh-muenster.de>, Steve Henson]

  *) Initial TLSv1.1 support. Since TLSv1.1 is very similar to TLS v1.0 only
     a few changes are required:

       Add SSL_OP_NO_TLSv1_1 flag.
       Add TLSv1_1 methods.
       Update version checking logic to handle version 1.1.
       Add explicit IV handling (ported from DTLS code).
       Add command line options to s_client/s_server.
     [Steve Henson]

 Changes between 1.0.0g and 1.0.0h [12 Mar 2012]

  *) Fix MMA (Bleichenbacher's attack on PKCS #1 v1.5 RSA padding) weakness
     in CMS and PKCS7 code. When RSA decryption fails use a random key for
     content decryption and always return the same error. Note: this attack
     needs on average 2^20 messages so it only affects automated senders. The
     old behaviour can be re-enabled in the CMS code by setting the
     CMS_DEBUG_DECRYPT flag: this is useful for debugging and testing where
     an MMA defence is not necessary.
     Thanks to Ivan Nestlerode <inestlerode@us.ibm.com> for discovering
     this issue. (CVE-2012-0884)
     [Steve Henson]

  *) Fix CVE-2011-4619: make sure we really are receiving a 
     client hello before rejecting multiple SGC restarts. Thanks to
     Ivan Nestlerode <inestlerode@us.ibm.com> for discovering this bug.
     [Steve Henson]

 Changes between 1.0.0f and 1.0.0g [18 Jan 2012]

  *) Fix for DTLS DoS issue introduced by fix for CVE-2011-4109.
     Thanks to Antonio Martin, Enterprise Secure Access Research and
     Development, Cisco Systems, Inc. for discovering this bug and
     preparing a fix. (CVE-2012-0050)
     [Antonio Martin]

 Changes between 1.0.0e and 1.0.0f [4 Jan 2012]

  *) Nadhem Alfardan and Kenny Paterson have discovered an extension
     of the Vaudenay padding oracle attack on CBC mode encryption
     which enables an efficient plaintext recovery attack against
     the OpenSSL implementation of DTLS. Their attack exploits timing
     differences arising during decryption processing. A research
     paper describing this attack can be found at:
                  http://www.isg.rhul.ac.uk/~kp/dtls.pdf
     Thanks go to Nadhem Alfardan and Kenny Paterson of the Information
     Security Group at Royal Holloway, University of London
     (www.isg.rhul.ac.uk) for discovering this flaw and to Robin Seggelmann
     <seggelmann@fh-muenster.de> and Michael Tuexen <tuexen@fh-muenster.de>
     for preparing the fix. (CVE-2011-4108)
     [Robin Seggelmann, Michael Tuexen]

  *) Clear bytes used for block padding of SSL 3.0 records.
     (CVE-2011-4576)
     [Adam Langley (Google)]

  *) Only allow one SGC handshake restart for SSL/TLS. Thanks to George
     Kadianakis <desnacked@gmail.com> for discovering this issue and
     Adam Langley for preparing the fix. (CVE-2011-4619)
     [Adam Langley (Google)]

  *) Check parameters are not NULL in GOST ENGINE. (CVE-2012-0027)
     [Andrey Kulikov <amdeich@gmail.com>]

  *) Prevent malformed RFC3779 data triggering an assertion failure.
     Thanks to Andrew Chi, BBN Technologies, for discovering the flaw
     and Rob Austein <sra@hactrn.net> for fixing it. (CVE-2011-4577)
     [Rob Austein <sra@hactrn.net>]

  *) Improved PRNG seeding for VOS.
     [Paul Green <Paul.Green@stratus.com>]

  *) Fix ssl_ciph.c set-up race.
     [Adam Langley (Google)]

  *) Fix spurious failures in ecdsatest.c.
     [Emilia Käsper (Google)]

  *) Fix the BIO_f_buffer() implementation (which was mixing different
     interpretations of the '..._len' fields).
     [Adam Langley (Google)]

  *) Fix handling of BN_BLINDING: now BN_BLINDING_invert_ex (rather than
     BN_BLINDING_invert_ex) calls BN_BLINDING_update, ensuring that concurrent
     threads won't reuse the same blinding coefficients.

     This also avoids the need to obtain the CRYPTO_LOCK_RSA_BLINDING
     lock to call BN_BLINDING_invert_ex, and avoids one use of
     BN_BLINDING_update for each BN_BLINDING structure (previously,
     the last update always remained unused).
     [Emilia Käsper (Google)]

  *) In ssl3_clear, preserve s3->init_extra along with s3->rbuf.
     [Bob Buckholz (Google)]

 Changes between 1.0.0d and 1.0.0e [6 Sep 2011]

  *) Fix bug where CRLs with nextUpdate in the past are sometimes accepted
     by initialising X509_STORE_CTX properly. (CVE-2011-3207)
     [Kaspar Brand <ossl@velox.ch>]

  *) Fix SSL memory handling for (EC)DH ciphersuites, in particular
     for multi-threaded use of ECDH. (CVE-2011-3210)
     [Adam Langley (Google)]

  *) Fix x509_name_ex_d2i memory leak on bad inputs.
     [Bodo Moeller]

  *) Remove hard coded ecdsaWithSHA1 signature tests in ssl code and check
     signature public key algorithm by using OID xref utilities instead.
     Before this you could only use some ECC ciphersuites with SHA1 only.
     [Steve Henson]

  *) Add protection against ECDSA timing attacks as mentioned in the paper
     by Billy Bob Brumley and Nicola Tuveri, see:

        http://eprint.iacr.org/2011/232.pdf

     [Billy Bob Brumley and Nicola Tuveri]

 Changes between 1.0.0c and 1.0.0d [8 Feb 2011]

  *) Fix parsing of OCSP stapling ClientHello extension. CVE-2011-0014
     [Neel Mehta, Adam Langley, Bodo Moeller (Google)]

  *) Fix bug in string printing code: if *any* escaping is enabled we must
     escape the escape character (backslash) or the resulting string is
     ambiguous.
     [Steve Henson]

 Changes between 1.0.0b and 1.0.0c  [2 Dec 2010]

  *) Disable code workaround for ancient and obsolete Netscape browsers
     and servers: an attacker can use it in a ciphersuite downgrade attack.
     Thanks to Martin Rex for discovering this bug. CVE-2010-4180
     [Steve Henson]

  *) Fixed J-PAKE implementation error, originally discovered by
     Sebastien Martini, further info and confirmation from Stefan
     Arentz and Feng Hao. Note that this fix is a security fix. CVE-2010-4252
     [Ben Laurie]

 Changes between 1.0.0a and 1.0.0b  [16 Nov 2010]

  *) Fix extension code to avoid race conditions which can result in a buffer
     overrun vulnerability: resumed sessions must not be modified as they can
     be shared by multiple threads. CVE-2010-3864
     [Steve Henson]

  *) Fix WIN32 build system to correctly link an ENGINE directory into
     a DLL. 
     [Steve Henson]

 Changes between 1.0.0 and 1.0.0a  [01 Jun 2010]

  *) Check return value of int_rsa_verify in pkey_rsa_verifyrecover 
     (CVE-2010-1633)
     [Steve Henson, Peter-Michael Hager <hager@dortmund.net>]

 Changes between 0.9.8n and 1.0.0  [29 Mar 2010]

  *) Add "missing" function EVP_CIPHER_CTX_copy(). This copies a cipher
     context. The operation can be customised via the ctrl mechanism in
     case ENGINEs want to include additional functionality.
     [Steve Henson]

  *) Tolerate yet another broken PKCS#8 key format: private key value negative.
     [Steve Henson]

  *) Add new -subject_hash_old and -issuer_hash_old options to x509 utility to
     output hashes compatible with older versions of OpenSSL.
     [Willy Weisz <weisz@vcpc.univie.ac.at>]

  *) Fix compression algorithm handling: if resuming a session use the
     compression algorithm of the resumed session instead of determining
     it from client hello again. Don't allow server to change algorithm.
     [Steve Henson]

  *) Add load_crls() function to apps tidying load_certs() too. Add option
     to verify utility to allow additional CRLs to be included.
     [Steve Henson]

  *) Update OCSP request code to permit adding custom headers to the request:
     some responders need this.
     [Steve Henson]

  *) The function EVP_PKEY_sign() returns <=0 on error: check return code
     correctly.
     [Julia Lawall <julia@diku.dk>]

  *) Update verify callback code in apps/s_cb.c and apps/verify.c, it
     needlessly dereferenced structures, used obsolete functions and
     didn't handle all updated verify codes correctly.
     [Steve Henson]

  *) Disable MD2 in the default configuration.
     [Steve Henson]

  *) In BIO_pop() and BIO_push() use the ctrl argument (which was NULL) to
     indicate the initial BIO being pushed or popped. This makes it possible
     to determine whether the BIO is the one explicitly called or as a result
     of the ctrl being passed down the chain. Fix BIO_pop() and SSL BIOs so
     it handles reference counts correctly and doesn't zero out the I/O bio
     when it is not being explicitly popped. WARNING: applications which
     included workarounds for the old buggy behaviour will need to be modified
     or they could free up already freed BIOs.
     [Steve Henson]

  *) Extend the uni2asc/asc2uni => OPENSSL_uni2asc/OPENSSL_asc2uni
     renaming to all platforms (within the 0.9.8 branch, this was
     done conditionally on Netware platforms to avoid a name clash).
     [Guenter <lists@gknw.net>]

  *) Add ECDHE and PSK support to DTLS.
     [Michael Tuexen <tuexen@fh-muenster.de>]

  *) Add CHECKED_STACK_OF macro to safestack.h, otherwise safestack can't
     be used on C++.
     [Steve Henson]

  *) Add "missing" function EVP_MD_flags() (without this the only way to
     retrieve a digest flags is by accessing the structure directly. Update
     EVP_MD_do_all*() and EVP_CIPHER_do_all*() to include the name a digest
     or cipher is registered as in the "from" argument. Print out all
     registered digests in the dgst usage message instead of manually 
     attempting to work them out.
     [Steve Henson]

  *) If no SSLv2 ciphers are used don't use an SSLv2 compatible client hello:
     this allows the use of compression and extensions. Change default cipher
     string to remove SSLv2 ciphersuites. This effectively avoids ancient SSLv2
     by default unless an application cipher string requests it.
     [Steve Henson]

  *) Alter match criteria in PKCS12_parse(). It used to try to use local
     key ids to find matching certificates and keys but some PKCS#12 files
     don't follow the (somewhat unwritten) rules and this strategy fails.
     Now just gather all certificates together and the first private key
     then look for the first certificate that matches the key.
     [Steve Henson]

  *) Support use of registered digest and cipher names for dgst and cipher
     commands instead of having to add each one as a special case. So now
     you can do:

        openssl sha256 foo

     as well as:

        openssl dgst -sha256 foo

     and this works for ENGINE based algorithms too.

     [Steve Henson]

  *) Update Gost ENGINE to support parameter files.
     [Victor B. Wagner <vitus@cryptocom.ru>]

  *) Support GeneralizedTime in ca utility. 
     [Oliver Martin <oliver@volatilevoid.net>, Steve Henson]

  *) Enhance the hash format used for certificate directory links. The new
     form uses the canonical encoding (meaning equivalent names will work
     even if they aren't identical) and uses SHA1 instead of MD5. This form
     is incompatible with the older format and as a result c_rehash should
     be used to rebuild symbolic links.
     [Steve Henson]

  *) Make PKCS#8 the default write format for private keys, replacing the
     traditional format. This form is standardised, more secure and doesn't
     include an implicit MD5 dependency.
     [Steve Henson]

  *) Add a $gcc_devteam_warn option to Configure. The idea is that any code
     committed to OpenSSL should pass this lot as a minimum.
     [Steve Henson]

  *) Add session ticket override functionality for use by EAP-FAST.
     [Jouni Malinen <j@w1.fi>]

  *) Modify HMAC functions to return a value. Since these can be implemented
     in an ENGINE errors can occur.
     [Steve Henson]

  *) Type-checked OBJ_bsearch_ex.
     [Ben Laurie]

  *) Type-checked OBJ_bsearch. Also some constification necessitated
     by type-checking.  Still to come: TXT_DB, bsearch(?),
     OBJ_bsearch_ex, qsort, CRYPTO_EX_DATA, ASN1_VALUE, ASN1_STRING,
     CONF_VALUE.
     [Ben Laurie]

  *) New function OPENSSL_gmtime_adj() to add a specific number of days and
     seconds to a tm structure directly, instead of going through OS
     specific date routines. This avoids any issues with OS routines such
     as the year 2038 bug. New *_adj() functions for ASN1 time structures
     and X509_time_adj_ex() to cover the extended range. The existing
     X509_time_adj() is still usable and will no longer have any date issues.
     [Steve Henson]

  *) Delta CRL support. New use deltas option which will attempt to locate
     and search any appropriate delta CRLs available.

     This work was sponsored by Google.
     [Steve Henson]

  *) Support for CRLs partitioned by reason code. Reorganise CRL processing
     code and add additional score elements. Validate alternate CRL paths
     as part of the CRL checking and indicate a new error "CRL path validation
     error" in this case. Applications wanting additional details can use
     the verify callback and check the new "parent" field. If this is not
     NULL CRL path validation is taking place. Existing applications won't
     see this because it requires extended CRL support which is off by
     default.

     This work was sponsored by Google.
     [Steve Henson]

  *) Support for freshest CRL extension.

     This work was sponsored by Google.
     [Steve Henson]

  *) Initial indirect CRL support. Currently only supported in the CRLs
     passed directly and not via lookup. Process certificate issuer
     CRL entry extension and lookup CRL entries by bother issuer name
     and serial number. Check and process CRL issuer entry in IDP extension.

     This work was sponsored by Google.
     [Steve Henson]

  *) Add support for distinct certificate and CRL paths. The CRL issuer
     certificate is validated separately in this case. Only enabled if
     an extended CRL support flag is set: this flag will enable additional
     CRL functionality in future.

     This work was sponsored by Google.
     [Steve Henson]

  *) Add support for policy mappings extension.

     This work was sponsored by Google.
     [Steve Henson]

  *) Fixes to pathlength constraint, self issued certificate handling,
     policy processing to align with RFC3280 and PKITS tests.

     This work was sponsored by Google.
     [Steve Henson]

  *) Support for name constraints certificate extension. DN, email, DNS
     and URI types are currently supported.

     This work was sponsored by Google.
     [Steve Henson]

  *) To cater for systems that provide a pointer-based thread ID rather
     than numeric, deprecate the current numeric thread ID mechanism and
     replace it with a structure and associated callback type. This
     mechanism allows a numeric "hash" to be extracted from a thread ID in
     either case, and on platforms where pointers are larger than 'long',
     mixing is done to help ensure the numeric 'hash' is usable even if it
     can't be guaranteed unique. The default mechanism is to use "&errno"
     as a pointer-based thread ID to distinguish between threads.

     Applications that want to provide their own thread IDs should now use
     CRYPTO_THREADID_set_callback() to register a callback that will call
     either CRYPTO_THREADID_set_numeric() or CRYPTO_THREADID_set_pointer().

     Note that ERR_remove_state() is now deprecated, because it is tied
     to the assumption that thread IDs are numeric.  ERR_remove_state(0)
     to free the current thread's error state should be replaced by
     ERR_remove_thread_state(NULL).

     (This new approach replaces the functions CRYPTO_set_idptr_callback(),
     CRYPTO_get_idptr_callback(), and CRYPTO_thread_idptr() that existed in
     OpenSSL 0.9.9-dev between June 2006 and August 2008. Also, if an
     application was previously providing a numeric thread callback that
     was inappropriate for distinguishing threads, then uniqueness might
     have been obtained with &errno that happened immediately in the
     intermediate development versions of OpenSSL; this is no longer the
     case, the numeric thread callback will now override the automatic use
     of &errno.)
     [Geoff Thorpe, with help from Bodo Moeller]

  *) Initial support for different CRL issuing certificates. This covers a
     simple case where the self issued certificates in the chain exist and
     the real CRL issuer is higher in the existing chain.

     This work was sponsored by Google.
     [Steve Henson]

  *) Removed effectively defunct crypto/store from the build.
     [Ben Laurie]

  *) Revamp of STACK to provide stronger type-checking. Still to come:
     TXT_DB, bsearch(?), OBJ_bsearch, qsort, CRYPTO_EX_DATA, ASN1_VALUE,
     ASN1_STRING, CONF_VALUE.
     [Ben Laurie]

  *) Add a new SSL_MODE_RELEASE_BUFFERS mode flag to release unused buffer
     RAM on SSL connections.  This option can save about 34k per idle SSL.
     [Nick Mathewson]

  *) Revamp of LHASH to provide stronger type-checking. Still to come:
     STACK, TXT_DB, bsearch, qsort.
     [Ben Laurie]

  *) Initial support for Cryptographic Message Syntax (aka CMS) based
     on RFC3850, RFC3851 and RFC3852. New cms directory and cms utility,
     support for data, signedData, compressedData, digestedData and
     encryptedData, envelopedData types included. Scripts to check against
     RFC4134 examples draft and interop and consistency checks of many
     content types and variants.
     [Steve Henson]

  *) Add options to enc utility to support use of zlib compression BIO.
     [Steve Henson]

  *) Extend mk1mf to support importing of options and assembly language
     files from Configure script, currently only included in VC-WIN32.
     The assembly language rules can now optionally generate the source
     files from the associated perl scripts.
     [Steve Henson]

  *) Implement remaining functionality needed to support GOST ciphersuites.
     Interop testing has been performed using CryptoPro implementations.
     [Victor B. Wagner <vitus@cryptocom.ru>]

  *) s390x assembler pack.
     [Andy Polyakov]

  *) ARMv4 assembler pack. ARMv4 refers to v4 and later ISA, not CPU
     "family."
     [Andy Polyakov]

  *) Implement Opaque PRF Input TLS extension as specified in
     draft-rescorla-tls-opaque-prf-input-00.txt.  Since this is not an
     official specification yet and no extension type assignment by
     IANA exists, this extension (for now) will have to be explicitly
     enabled when building OpenSSL by providing the extension number
     to use.  For example, specify an option

         -DTLSEXT_TYPE_opaque_prf_input=0x9527

     to the "config" or "Configure" script to enable the extension,
     assuming extension number 0x9527 (which is a completely arbitrary
     and unofficial assignment based on the MD5 hash of the Internet
     Draft).  Note that by doing so, you potentially lose
     interoperability with other TLS implementations since these might
     be using the same extension number for other purposes.

     SSL_set_tlsext_opaque_prf_input(ssl, src, len) is used to set the
     opaque PRF input value to use in the handshake.  This will create
     an interal copy of the length-'len' string at 'src', and will
     return non-zero for success.

     To get more control and flexibility, provide a callback function
     by using

          SSL_CTX_set_tlsext_opaque_prf_input_callback(ctx, cb)
          SSL_CTX_set_tlsext_opaque_prf_input_callback_arg(ctx, arg)

     where

          int (*cb)(SSL *, void *peerinput, size_t len, void *arg);
          void *arg;

     Callback function 'cb' will be called in handshakes, and is
     expected to use SSL_set_tlsext_opaque_prf_input() as appropriate.
     Argument 'arg' is for application purposes (the value as given to
     SSL_CTX_set_tlsext_opaque_prf_input_callback_arg() will directly
     be provided to the callback function).  The callback function
     has to return non-zero to report success: usually 1 to use opaque
     PRF input just if possible, or 2 to enforce use of the opaque PRF
     input.  In the latter case, the library will abort the handshake
     if opaque PRF input is not successfully negotiated.

     Arguments 'peerinput' and 'len' given to the callback function
     will always be NULL and 0 in the case of a client.  A server will
     see the client's opaque PRF input through these variables if
     available (NULL and 0 otherwise).  Note that if the server
     provides an opaque PRF input, the length must be the same as the
     length of the client's opaque PRF input.

     Note that the callback function will only be called when creating
     a new session (session resumption can resume whatever was
     previously negotiated), and will not be called in SSL 2.0
     handshakes; thus, SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2) or
     SSL_set_options(ssl, SSL_OP_NO_SSLv2) is especially recommended
     for applications that need to enforce opaque PRF input.

     [Bodo Moeller]

  *) Update ssl code to support digests other than SHA1+MD5 for handshake
     MAC. 

     [Victor B. Wagner <vitus@cryptocom.ru>]

  *) Add RFC4507 support to OpenSSL. This includes the corrections in
     RFC4507bis. The encrypted ticket format is an encrypted encoded
     SSL_SESSION structure, that way new session features are automatically
     supported.

     If a client application caches session in an SSL_SESSION structure
     support is transparent because tickets are now stored in the encoded
     SSL_SESSION.
     
     The SSL_CTX structure automatically generates keys for ticket
     protection in servers so again support should be possible
     with no application modification.

     If a client or server wishes to disable RFC4507 support then the option
     SSL_OP_NO_TICKET can be set.

     Add a TLS extension debugging callback to allow the contents of any client
     or server extensions to be examined.

     This work was sponsored by Google.
     [Steve Henson]

  *) Final changes to avoid use of pointer pointer casts in OpenSSL.
     OpenSSL should now compile cleanly on gcc 4.2
     [Peter Hartley <pdh@utter.chaos.org.uk>, Steve Henson]

  *) Update SSL library to use new EVP_PKEY MAC API. Include generic MAC
     support including streaming MAC support: this is required for GOST
     ciphersuite support.
     [Victor B. Wagner <vitus@cryptocom.ru>, Steve Henson]

  *) Add option -stream to use PKCS#7 streaming in smime utility. New
     function i2d_PKCS7_bio_stream() and PEM_write_PKCS7_bio_stream()
     to output in BER and PEM format.
     [Steve Henson]

  *) Experimental support for use of HMAC via EVP_PKEY interface. This
     allows HMAC to be handled via the EVP_DigestSign*() interface. The
     EVP_PKEY "key" in this case is the HMAC key, potentially allowing
     ENGINE support for HMAC keys which are unextractable. New -mac and
     -macopt options to dgst utility.
     [Steve Henson]

  *) New option -sigopt to dgst utility. Update dgst to use
     EVP_Digest{Sign,Verify}*. These two changes make it possible to use
     alternative signing parameters such as X9.31 or PSS in the dgst 
     utility.
     [Steve Henson]

  *) Change ssl_cipher_apply_rule(), the internal function that does
     the work each time a ciphersuite string requests enabling
     ("foo+bar"), moving ("+foo+bar"), disabling ("-foo+bar", or
     removing ("!foo+bar") a class of ciphersuites: Now it maintains
     the order of disabled ciphersuites such that those ciphersuites
     that most recently went from enabled to disabled not only stay
     in order with respect to each other, but also have higher priority
     than other disabled ciphersuites the next time ciphersuites are
     enabled again.

     This means that you can now say, e.g., "PSK:-PSK:HIGH" to enable
     the same ciphersuites as with "HIGH" alone, but in a specific
     order where the PSK ciphersuites come first (since they are the
     most recently disabled ciphersuites when "HIGH" is parsed).

     Also, change ssl_create_cipher_list() (using this new
     funcionality) such that between otherwise identical
     cihpersuites, ephemeral ECDH is preferred over ephemeral DH in
     the default order.
     [Bodo Moeller]

  *) Change ssl_create_cipher_list() so that it automatically
     arranges the ciphersuites in reasonable order before starting
     to process the rule string.  Thus, the definition for "DEFAULT"
     (SSL_DEFAULT_CIPHER_LIST) now is just "ALL:!aNULL:!eNULL", but
     remains equivalent to "AES:ALL:!aNULL:!eNULL:+aECDH:+kRSA:+RC4:@STRENGTH".
     This makes it much easier to arrive at a reasonable default order
     in applications for which anonymous ciphers are OK (meaning
     that you can't actually use DEFAULT).
     [Bodo Moeller; suggested by Victor Duchovni]

  *) Split the SSL/TLS algorithm mask (as used for ciphersuite string
     processing) into multiple integers instead of setting
     "SSL_MKEY_MASK" bits, "SSL_AUTH_MASK" bits, "SSL_ENC_MASK",
     "SSL_MAC_MASK", and "SSL_SSL_MASK" bits all in a single integer.
     (These masks as well as the individual bit definitions are hidden
     away into the non-exported interface ssl/ssl_locl.h, so this
     change to the definition of the SSL_CIPHER structure shouldn't
     affect applications.)  This give us more bits for each of these
     categories, so there is no longer a need to coagulate AES128 and
     AES256 into a single algorithm bit, and to coagulate Camellia128
     and Camellia256 into a single algorithm bit, which has led to all
     kinds of kludges.

     Thus, among other things, the kludge introduced in 0.9.7m and
     0.9.8e for masking out AES256 independently of AES128 or masking
     out Camellia256 independently of AES256 is not needed here in 0.9.9.

     With the change, we also introduce new ciphersuite aliases that
     so far were missing: "AES128", "AES256", "CAMELLIA128", and
     "CAMELLIA256".
     [Bodo Moeller]

  *) Add support for dsa-with-SHA224 and dsa-with-SHA256.
     Use the leftmost N bytes of the signature input if the input is
     larger than the prime q (with N being the size in bytes of q).
     [Nils Larsch]

  *) Very *very* experimental PKCS#7 streaming encoder support. Nothing uses
     it yet and it is largely untested.
     [Steve Henson]

  *) Add support for the ecdsa-with-SHA224/256/384/512 signature types.
     [Nils Larsch]

  *) Initial incomplete changes to avoid need for function casts in OpenSSL
     some compilers (gcc 4.2 and later) reject their use. Safestack is
     reimplemented.  Update ASN1 to avoid use of legacy functions. 
     [Steve Henson]

  *) Win32/64 targets are linked with Winsock2.
     [Andy Polyakov]

  *) Add an X509_CRL_METHOD structure to allow CRL processing to be redirected
     to external functions. This can be used to increase CRL handling 
     efficiency especially when CRLs are very large by (for example) storing
     the CRL revoked certificates in a database.
     [Steve Henson]

  *) Overhaul of by_dir code. Add support for dynamic loading of CRLs so
     new CRLs added to a directory can be used. New command line option
     -verify_return_error to s_client and s_server. This causes real errors
     to be returned by the verify callback instead of carrying on no matter
     what. This reflects the way a "real world" verify callback would behave.
     [Steve Henson]

  *) GOST engine, supporting several GOST algorithms and public key formats.
     Kindly donated by Cryptocom.
     [Cryptocom]

  *) Partial support for Issuing Distribution Point CRL extension. CRLs
     partitioned by DP are handled but no indirect CRL or reason partitioning
     (yet). Complete overhaul of CRL handling: now the most suitable CRL is
     selected via a scoring technique which handles IDP and AKID in CRLs.
     [Steve Henson]

  *) New X509_STORE_CTX callbacks lookup_crls() and lookup_certs() which
     will ultimately be used for all verify operations: this will remove the
     X509_STORE dependency on certificate verification and allow alternative
     lookup methods.  X509_STORE based implementations of these two callbacks.
     [Steve Henson]

  *) Allow multiple CRLs to exist in an X509_STORE with matching issuer names.
     Modify get_crl() to find a valid (unexpired) CRL if possible.
     [Steve Henson]

  *) New function X509_CRL_match() to check if two CRLs are identical. Normally
     this would be called X509_CRL_cmp() but that name is already used by
     a function that just compares CRL issuer names. Cache several CRL 
     extensions in X509_CRL structure and cache CRLDP in X509.
     [Steve Henson]

  *) Store a "canonical" representation of X509_NAME structure (ASN1 Name)
     this maps equivalent X509_NAME structures into a consistent structure.
     Name comparison can then be performed rapidly using memcmp().
     [Steve Henson]

  *) Non-blocking OCSP request processing. Add -timeout option to ocsp 
     utility.
     [Steve Henson]

  *) Allow digests to supply their own micalg string for S/MIME type using
     the ctrl EVP_MD_CTRL_MICALG.
     [Steve Henson]

  *) During PKCS7 signing pass the PKCS7 SignerInfo structure to the
     EVP_PKEY_METHOD before and after signing via the EVP_PKEY_CTRL_PKCS7_SIGN
     ctrl. It can then customise the structure before and/or after signing
     if necessary.
     [Steve Henson]

  *) New function OBJ_add_sigid() to allow application defined signature OIDs
     to be added to OpenSSLs internal tables. New function OBJ_sigid_free()
     to free up any added signature OIDs.
     [Steve Henson]

  *) New functions EVP_CIPHER_do_all(), EVP_CIPHER_do_all_sorted(),
     EVP_MD_do_all() and EVP_MD_do_all_sorted() to enumerate internal
     digest and cipher tables. New options added to openssl utility:
     list-message-digest-algorithms and list-cipher-algorithms.
     [Steve Henson]

  *) Change the array representation of binary polynomials: the list
     of degrees of non-zero coefficients is now terminated with -1.
     Previously it was terminated with 0, which was also part of the
     value; thus, the array representation was not applicable to
     polynomials where t^0 has coefficient zero.  This change makes
     the array representation useful in a more general context.
     [Douglas Stebila]

  *) Various modifications and fixes to SSL/TLS cipher string
     handling.  For ECC, the code now distinguishes between fixed ECDH
     with RSA certificates on the one hand and with ECDSA certificates
     on the other hand, since these are separate ciphersuites.  The
     unused code for Fortezza ciphersuites has been removed.

     For consistency with EDH, ephemeral ECDH is now called "EECDH"
     (not "ECDHE").  For consistency with the code for DH
     certificates, use of ECDH certificates is now considered ECDH
     authentication, not RSA or ECDSA authentication (the latter is
     merely the CA's signing algorithm and not actively used in the
     protocol).

     The temporary ciphersuite alias "ECCdraft" is no longer
     available, and ECC ciphersuites are no longer excluded from "ALL"
     and "DEFAULT".  The following aliases now exist for RFC 4492
     ciphersuites, most of these by analogy with the DH case: