* Why is OpenSSL x509 DN output not conformant to RFC2253?
* What is a "128 bit certificate"? Can I create one with OpenSSL?
* Why does OpenSSL set the authority key identifier extension incorrectly?
+* How can I set up a bundle of commercial root CA certificates?
[BUILD] Questions about building and testing OpenSSL
* Why doesn't my server application receive a client certificate?
* Why does compilation fail due to an undefined symbol NID_uniqueIdentifier?
* I think I've detected a memory leak, is this a bug?
+* Why does Valgrind complain about the use of uninitialized data?
+* Why doesn't a memory BIO work when a file does?
+* Where are the declarations and implementations of d2i_X509() etc?
===============================================================================
* Which is the current version of OpenSSL?
The current version is available from <URL: http://www.openssl.org>.
-OpenSSL 0.9.8a was released on October 11th, 2005.
+OpenSSL 0.9.8k was released on Mar 25th, 2009.
In addition to the current stable release, you can also access daily
snapshots of the OpenSSL development version at <URL:
OpenSSL includes a command line utility that can be used to perform a
variety of cryptographic functions. It is described in the openssl(1)
-manpage. Documentation for developers is currently being written. A
-few manual pages already are available; overviews over libcrypto and
+manpage. Documentation for developers is currently being written. Many
+manual pages are available; overviews over libcrypto and
libssl are given in the crypto(3) and ssl(3) manpages.
The OpenSSL manpages are installed in /usr/local/ssl/man/ (or a
different directory if you specified one as described in INSTALL).
In addition, you can read the most current versions at
-<URL: http://www.openssl.org/docs/>.
+<URL: http://www.openssl.org/docs/>. Note that the online documents refer
+to the very latest development versions of OpenSSL and may include features
+not present in released versions. If in doubt refer to the documentation
+that came with the version of OpenSSL you are using.
For information on parts of libcrypto that are not yet documented, you
might want to read Ariel Glenn's documentation on SSLeay 0.9, OpenSSL's
need to any more. Nowadays web browsers using unrestricted strong encryption
are generally available.
-When there were tight export restrictions on the export of strong encryption
+When there were tight restrictions on the export of strong encryption
software from the US only weak encryption algorithms could be freely exported
(initially 40 bit and then 56 bit). It was widely recognised that this was
-inadequate. A relaxation the rules allowed the use of strong encryption but
+inadequate. A relaxation of the rules allowed the use of strong encryption but
only to an authorised server.
Two slighly different techniques were developed to support this, one used by
It doesn't: this extension is often the cause of confusion.
-Consider a certificate chain A->B->C so that A signs, B and B signs C. Suppose
+Consider a certificate chain A->B->C so that A signs B and B signs C. Suppose
certificate C contains AKID.
The purpose of this extension is to identify the authority certificate B. This
name of C.
+* How can I set up a bundle of commercial root CA certificates?
+
+The OpenSSL software is shipped without any root CA certificate as the
+OpenSSL project does not have any policy on including or excluding
+any specific CA and does not intend to set up such a policy. Deciding
+about which CAs to support is up to application developers or
+administrators.
+
+Other projects do have other policies so you can for example extract the CA
+bundle used by Mozilla and/or modssl as described in this article:
+
+ http://www.mail-archive.com/modssl-users@modssl.org/msg16980.html
+
+
[BUILD] =======================================================================
* Why does the linker complain about undefined symbols?
file.
Multi-threaded applications must provide two callback functions to
-OpenSSL. This is described in the threads(3) manpage.
-
+OpenSSL by calling CRYPTO_set_locking_callback() and
+CRYPTO_set_id_callback(), for all versions of OpenSSL up to and
+including 0.9.8[abc...]. As of version 0.9.9, CRYPTO_set_id_callback()
+and associated APIs are deprecated by CRYPTO_THREADID_set_callback()
+and friends. This is described in the threads(3) manpage.
* I've compiled a program under Windows and it crashes: why?
* Why do I get errors about unknown algorithms?
-This can happen under several circumstances such as reading in an
-encrypted private key or attempting to decrypt a PKCS#12 file. The cause
-is forgetting to load OpenSSL's table of algorithms with
-OpenSSL_add_all_algorithms(). See the manual page for more information.
-
+The cause is forgetting to load OpenSSL's table of algorithms with
+OpenSSL_add_all_algorithms(). See the manual page for more information. This
+can cause several problems such as being unable to read in an encrypted
+PEM file, unable to decrypt a PKCS#12 file or signature failure when
+verifying certificates.
* Why can't the OpenSSH configure script detect OpenSSL?
ERR_free_strings(), EVP_cleanup() and CRYPTO_cleanup_all_ex_data().
-===============================================================================
+* Why does Valgrind complain about the use of uninitialized data?
+
+When OpenSSL's PRNG routines are called to generate random numbers the supplied
+buffer contents are mixed into the entropy pool: so it technically does not
+matter whether the buffer is initialized at this point or not. Valgrind (and
+other test tools) will complain about this. When using Valgrind, make sure the
+OpenSSL library has been compiled with the PURIFY macro defined (-DPURIFY)
+to get rid of these warnings.
+
+
+* Why doesn't a memory BIO work when a file does?
+
+This can occur in several cases for example reading an S/MIME email message.
+The reason is that a memory BIO can do one of two things when all the data
+has been read from it.
+
+The default behaviour is to indicate that no more data is available and that
+the call should be retried, this is to allow the application to fill up the BIO
+again if necessary.
+Alternatively it can indicate that no more data is available and that EOF has
+been reached.
+
+If a memory BIO is to behave in the same way as a file this second behaviour
+is needed. This must be done by calling:
+
+ BIO_set_mem_eof_return(bio, 0);
+
+See the manual pages for more details.
+
+
+* Where are the declarations and implementations of d2i_X509() etc?
+
+These are defined and implemented by macros of the form:
+
+
+ DECLARE_ASN1_FUNCTIONS(X509) and IMPLEMENT_ASN1_FUNCTIONS(X509)
+
+The implementation passes an ASN1 "template" defining the structure into an
+ASN1 interpreter using generalised functions such as ASN1_item_d2i().
+
+
+===============================================================================
projects / openssl.git / blobdiff