* How can I contact the OpenSSL developers?
* Where can I get a compiled version of OpenSSL?
* Why aren't tools like 'autoconf' and 'libtool' used?
+* What is an 'engine' version?
+* How do I check the authenticity of the OpenSSL distribution?
[LEGAL] Legal questions
[USER] Questions on using the OpenSSL applications
* Why do I get a "PRNG not seeded" error message?
+* Why do I get an "unable to write 'random state'" error message?
* How do I create certificates or certificate requests?
* Why can't I create certificate requests?
* Why does <SSL program> fail with a certificate verify error?
* How can I remove the passphrase on a private key?
* Why can't I use OpenSSL certificates with SSL client authentication?
* Why does my browser give a warning about a mismatched hostname?
+* How do I install a CA certificate into a browser?
+* Why is OpenSSL x509 DN output not conformant to RFC2253?
[BUILD] Questions about building and testing OpenSSL
* Why does the linker complain about undefined symbols?
* Why does the OpenSSL test fail with "bc: command not found"?
* Why does the OpenSSL test fail with "bc: 1 no implemented"?
-* Why does the OpenSSL compilation fail on Alpha True64 Unix?
+* Why does the OpenSSL test fail with "bc: stack empty"?
+* Why does the OpenSSL compilation fail on Alpha Tru64 Unix?
* Why does the OpenSSL compilation fail with "ar: command not found"?
* Why does the OpenSSL compilation fail on Win32 with VC++?
+* What is special about OpenSSL on Redhat?
+* Why does the OpenSSL compilation fail on MacOS X?
+* Why does the OpenSSL test suite fail on MacOS X?
+* Why does the OpenSSL test suite fail in BN_sqr test [on a 64-bit platform]?
+* Why does OpenBSD-i386 build fail on des-586.s with "Unimplemented segment type"?
[PROG] Questions about programming with OpenSSL
* Why can't the OpenSSH configure script detect OpenSSL?
* Can I use OpenSSL's SSL library with non-blocking I/O?
* Why doesn't my server application receive a client certificate?
+* Why does compilation fail due to an undefined symbol NID_uniqueIdentifier?
===============================================================================
* Which is the current version of OpenSSL?
The current version is available from <URL: http://www.openssl.org>.
-OpenSSL 0.9.6a was released on April 5th, 2001.
+OpenSSL 0.9.7 was released on December 31, 2002.
In addition to the current stable release, you can also access daily
snapshots of the OpenSSL development version at <URL:
autoconf will probably be used in future OpenSSL versions. If it was
less Unix-centric, it might have been used much earlier.
+* What is an 'engine' version?
+
+With version 0.9.6 OpenSSL was extended to interface to external crypto
+hardware. This was realized in a special release '0.9.6-engine'. With
+version 0.9.7 (not yet released) the changes were merged into the main
+development line, so that the special release is no longer necessary.
+
+* How do I check the authenticity of the OpenSSL distribution?
+
+We provide MD5 digests and ASC signatures of each tarball.
+Use MD5 to check that a tarball from a mirror site is identical:
+
+ md5sum TARBALL | awk '{print $1;}' | cmp - TARBALL.md5
+
+You can check authenticity using pgp or gpg. You need the OpenSSL team
+member public key used to sign it (download it from a key server). Then
+just do:
+
+ pgp TARBALL.asc
[LEGAL] =======================================================================
their software on operating systems that don't normally include OpenSSL.
If you develop open source software that uses OpenSSL, you may find it
-useful to choose an other license than the GPL, or state explicitely that
+useful to choose an other license than the GPL, or state explicitly that
"This program is released under the GPL with the additional exemption that
compiling, linking, and/or using OpenSSL is allowed." If you are using
GPL software developed by others, you may want to ask the copyright holder
Cryptographic software needs a source of unpredictable data to work
correctly. Many open source operating systems provide a "randomness
-device" that serves this purpose. On other systems, applications have
-to call the RAND_add() or RAND_seed() function with appropriate data
-before generating keys or performing public key encryption.
-
-Some broken applications do not do this. As of version 0.9.5, the
-OpenSSL functions that need randomness report an error if the random
-number generator has not been seeded with at least 128 bits of
-randomness. If this error occurs, please contact the author of the
-application you are using. It is likely that it never worked
-correctly. OpenSSL 0.9.5 and later make the error visible by refusing
-to perform potentially insecure encryption.
+device" (/dev/urandom or /dev/random) that serves this purpose.
+All OpenSSL versions try to use /dev/urandom by default; starting with
+version 0.9.7, OpenSSL also tries /dev/random if /dev/urandom is not
+available.
+
+On other systems, applications have to call the RAND_add() or
+RAND_seed() function with appropriate data before generating keys or
+performing public key encryption. (These functions initialize the
+pseudo-random number generator, PRNG.) Some broken applications do
+not do this. As of version 0.9.5, the OpenSSL functions that need
+randomness report an error if the random number generator has not been
+seeded with at least 128 bits of randomness. If this error occurs and
+is not discussed in the documentation of the application you are
+using, please contact the author of that application; it is likely
+that it never worked correctly. OpenSSL 0.9.5 and later make the
+error visible by refusing to perform potentially insecure encryption.
+
+If you are using Solaris 8, you can add /dev/urandom and /dev/random
+devices by installing patch 112438 (Sparc) or 112439 (x86), which are
+available via the Patchfinder at <URL: http://sunsolve.sun.com>
+(Solaris 9 includes these devices by default). For /dev/random support
+for earlier Solaris versions, see Sun's statement at
+<URL: http://sunsolve.sun.com/pub-cgi/retrieve.pl?doc=fsrdb/27606&zone_32=SUNWski>
+(the SUNWski package is available in patch 105710).
On systems without /dev/urandom and /dev/random, it is a good idea to
use the Entropy Gathering Demon (EGD); see the RAND_egd() manpage for
for an EGD socket at /var/run/egd-pool, /dev/egd-pool, /etc/egd-pool and
/etc/entropy.
-Most components of the openssl command line tool try to use the
-file $HOME/.rnd (or $RANDFILE, if this environment variable is set)
-for seeding the PRNG. If this file does not exist or is too short,
-the "PRNG not seeded" error message may occur.
+Most components of the openssl command line utility automatically try
+to seed the random number generator from a file. The name of the
+default seeding file is determined as follows: If environment variable
+RANDFILE is set, then it names the seeding file. Otherwise if
+environment variable HOME is set, then the seeding file is $HOME/.rnd.
+If neither RANDFILE nor HOME is set, versions up to OpenSSL 0.9.6 will
+use file .rnd in the current directory while OpenSSL 0.9.6a uses no
+default seeding file at all. OpenSSL 0.9.6b and later will behave
+similarly to 0.9.6a, but will use a default of "C:\" for HOME on
+Windows systems if the environment variable has not been set.
+
+If the default seeding file does not exist or is too short, the "PRNG
+not seeded" error message may occur.
+
+The openssl command line utility will write back a new state to the
+default seeding file (and create this file if necessary) unless
+there was no sufficient seeding.
+
Pointing $RANDFILE to an Entropy Gathering Daemon socket does not work.
Use the "-rand" option of the OpenSSL command line tools instead.
The $RANDFILE environment variable and $HOME/.rnd are only used by the
provide their own configuration options to specify the entropy source,
please check out the documentation coming the with application.
-For Solaris 2.6, Tim Nibbe <tnibbe@sprint.net> and others have suggested
-installing the SUNski package from Sun patch 105710-01 (Sparc) which
-adds a /dev/random device and make sure it gets used, usually through
-$RANDFILE. There are probably similar patches for the other Solaris
-versions. However, be warned that /dev/random is usually a blocking
-device, which may have some effects on OpenSSL.
+
+* Why do I get an "unable to write 'random state'" error message?
+
+
+Sometimes the openssl command line utility does not abort with
+a "PRNG not seeded" error message, but complains that it is
+"unable to write 'random state'". This message refers to the
+default seeding file (see previous answer). A possible reason
+is that no default filename is known because neither RANDFILE
+nor HOME is set. (Versions up to 0.9.6 used file ".rnd" in the
+current directory in this case, but this has changed with 0.9.6a.)
* How do I create certificates or certificate requests?
reject.
The solution is to add the relevant CA certificate to your servers "trusted
-CA list". How you do this depends on the server sofware in uses. You can
+CA list". How you do this depends on the server software in uses. You can
print out the servers list of acceptable CAs using the OpenSSL s_client tool:
openssl s_client -connect www.some.host:443 -prexit
(CN) field of the certificate. If it does not then you get a warning.
+* How do I install a CA certificate into a browser?
+
+The usual way is to send the DER encoded certificate to the browser as
+MIME type application/x-x509-ca-cert, for example by clicking on an appropriate
+link. On MSIE certain extensions such as .der or .cacert may also work, or you
+can import the certificate using the certificate import wizard.
+
+You can convert a certificate to DER form using the command:
+
+openssl x509 -in ca.pem -outform DER -out ca.der
+
+Occasionally someone suggests using a command such as:
+
+openssl pkcs12 -export -out cacert.p12 -in cacert.pem -inkey cakey.pem
+
+DO NOT DO THIS! This command will give away your CAs private key and
+reduces its security to zero: allowing anyone to forge certificates in
+whatever name they choose.
+
+* Why is OpenSSL x509 DN output not conformant to RFC2253?
+
+The ways to print out the oneline format of the DN (Distinguished Name) have
+been extended in version 0.9.7 of OpenSSL. Using the new X509_NAME_print_ex()
+interface, the "-nameopt" option could be introduded. See the manual
+page of the "openssl x509" commandline tool for details. The old behaviour
+has however been left as default for the sake of compatibility.
+
[BUILD] =======================================================================
* Why does the linker complain about undefined symbols?
for download instructions) can be safely used, for example.
-* Why does the OpenSSL compilation fail on Alpha True64 Unix?
+* Why does the OpenSSL test fail with "bc: stack empty"?
+
+On some DG/ux versions, bc seems to have a too small stack for calculations
+that the OpenSSL bntest throws at it. This gets triggered when you run the
+test suite (using "make test"). The message returned is "bc: stack empty".
+
+The best way to deal with this is to find another implementation of bc
+and compile/install it. GNU bc (see http://www.gnu.org/software/software.html
+for download instructions) can be safely used, for example.
+
+
+* Why does the OpenSSL compilation fail on Alpha Tru64 Unix?
-On some Alpha installations running True64 Unix and Compaq C, the compilation
+On some Alpha installations running Tru64 Unix and Compaq C, the compilation
of crypto/sha/sha_dgst.c fails with the message 'Fatal: Insufficient virtual
memory to continue compilation.' As far as the tests have shown, this may be
a compiler bug. What happens is that it eats up a lot of resident memory
Sometimes, you may get reports from VC++ command line (cl) that it
can't find standard include files like stdio.h and other weirdnesses.
One possible cause is that the environment isn't correctly set up.
-To solve that problem, one should run VCVARS32.BAT which is found in
-the 'bin' subdirectory of the VC++ installation directory (somewhere
-under 'Program Files'). This needs to be done prior to running NMAKE,
-and the changes are only valid for the current DOS session.
-
+To solve that problem for VC++ versions up to 6, one should run
+VCVARS32.BAT which is found in the 'bin' subdirectory of the VC++
+installation directory (somewhere under 'Program Files'). For VC++
+version 7 (and up?), which is also called VS.NET, the file is called
+VSVARS32.BAT instead.
+This needs to be done prior to running NMAKE, and the changes are only
+valid for the current DOS session.
+
+
+* What is special about OpenSSL on Redhat?
+
+Red Hat Linux (release 7.0 and later) include a preinstalled limited
+version of OpenSSL. For patent reasons, support for IDEA, RC5 and MDC2
+is disabled in this version. The same may apply to other Linux distributions.
+Users may therefore wish to install more or all of the features left out.
+
+To do this you MUST ensure that you do not overwrite the openssl that is in
+/usr/bin on your Red Hat machine. Several packages depend on this file,
+including sendmail and ssh. /usr/local/bin is a good alternative choice. The
+libraries that come with Red Hat 7.0 onwards have different names and so are
+not affected. (eg For Red Hat 7.2 they are /lib/libssl.so.0.9.6b and
+/lib/libcrypto.so.0.9.6b with symlinks /lib/libssl.so.2 and
+/lib/libcrypto.so.2 respectively).
+
+Please note that we have been advised by Red Hat attempting to recompile the
+openssl rpm with all the cryptography enabled will not work. All other
+packages depend on the original Red Hat supplied openssl package. It is also
+worth noting that due to the way Red Hat supplies its packages, updates to
+openssl on each distribution never change the package version, only the
+build number. For example, on Red Hat 7.1, the latest openssl package has
+version number 0.9.6 and build number 9 even though it contains all the
+relevant updates in packages up to and including 0.9.6b.
+
+A possible way around this is to persuade Red Hat to produce a non-US
+version of Red Hat Linux.
+
+FYI: Patent numbers and expiry dates of US patents:
+MDC-2: 4,908,861 13/03/2007
+IDEA: 5,214,703 25/05/2010
+RC5: 5,724,428 03/03/2015
+
+
+* Why does the OpenSSL compilation fail on MacOS X?
+
+If the failure happens when trying to build the "openssl" binary, with
+a large number of undefined symbols, it's very probable that you have
+OpenSSL 0.9.6b delivered with the operating system (you can find out by
+running '/usr/bin/openssl version') and that you were trying to build
+OpenSSL 0.9.7 or newer. The problem is that the loader ('ld') in
+MacOS X has a misfeature that's quite difficult to go around.
+Look in the file PROBLEMS for a more detailed explanation and for possible
+solutions.
+
+
+* Why does the OpenSSL test suite fail on MacOS X?
+
+If the failure happens when running 'make test' and the RC4 test fails,
+it's very probable that you have OpenSSL 0.9.6b delivered with the
+operating system (you can find out by running '/usr/bin/openssl version')
+and that you were trying to build OpenSSL 0.9.6d. The problem is that
+the loader ('ld') in MacOS X has a misfeature that's quite difficult to
+go around and has linked the programs "openssl" and the test programs
+with /usr/lib/libcrypto.dylib and /usr/lib/libssl.dylib instead of the
+libraries you just built.
+Look in the file PROBLEMS for a more detailed explanation and for possible
+solutions.
+
+* Why does the OpenSSL test suite fail in BN_sqr test [on a 64-bit platform]?
+
+Failure in BN_sqr test is most likely caused by a failure to configure the
+toolkit for current platform or lack of support for the platform in question.
+Run './config -t' and './apps/openssl version -p'. Do these platform
+identifiers match? If they don't, then you most likely failed to run
+./config and you're hereby advised to do so before filing a bug report.
+If ./config itself fails to run, then it's most likely problem with your
+local environment and you should turn to your system administrator (or
+similar). If identifiers match (and/or no alternative identifier is
+suggested by ./config script), then the platform is unsupported. There might
+or might not be a workaround. Most notably on SPARC64 platforms with GNU
+C compiler you should be able to produce a working build by running
+'./config -m32'. I understand that -m32 might not be what you want/need,
+but the build should be operational. For further details turn to
+<openssl-dev@openssl.org>.
+
+* Why does OpenBSD-i386 build fail on des-586.s with "Unimplemented segment type"?
+
+As of 0.9.7 assembler routines were overhauled for position independence
+of the machine code, which is essential for shared library support. For
+some reason OpenBSD is equipped with an out-of-date GNU assembler which
+finds the new code offensive. To work around the problem, configure with
+no-asm (and sacrifice a great deal of performance) or patch your assembler
+according to <URL: http://www.openssl.org/~appro/gas-1.92.3.OpenBSD.patch>.
+For your convenience a pre-compiled replacement binary is provided at
+<URL: http://www.openssl.org/~appro/gas-1.92.3.static.aout.bin>.
+Reportedly elder *BSD a.out platforms also suffer from this problem and
+remedy should be same. Provided binary is statically linked and should be
+working across wider range of *BSD branches, not just OpenBSD.
[PROG] ========================================================================
* I've compiled a program under Windows and it crashes: why?
-This is usually because you've missed the comment in INSTALL.W32. You
-must link with the multithreaded DLL version of the VC++ runtime library
-otherwise the conflict will cause a program to crash: typically on the
-first BIO related read or write operation.
+This is usually because you've missed the comment in INSTALL.W32.
+Your application must link against the same version of the Win32
+C-Runtime against which your openssl libraries were linked. The
+default version for OpenSSL is /MD - "Multithreaded DLL".
+
+If you are using Microsoft Visual C++'s IDE (Visual Studio), in
+many cases, your new project most likely defaulted to "Debug
+Singlethreaded" - /ML. This is NOT interchangeable with /MD and your
+program will crash, typically on the first BIO related read or write
+operation.
+
+For each of the six possible link stage configurations within Win32,
+your application must link against the same by which OpenSSL was
+built. If you are using MS Visual C++ (Studio) this can be changed
+by:
+
+1. Select Settings... from the Project Menu.
+2. Select the C/C++ Tab.
+3. Select "Code Generation from the "Category" drop down list box
+4. Select the Appropriate library (see table below) from the "Use
+ run-time library" drop down list box. Perform this step for both
+ your debug and release versions of your application (look at the
+ top left of the settings panel to change between the two)
+
+ Single Threaded /ML - MS VC++ often defaults to
+ this for the release
+ version of a new project.
+ Debug Single Threaded /MLd - MS VC++ often defaults to
+ this for the debug version
+ of a new project.
+ Multithreaded /MT
+ Debug Multithreaded /MTd
+ Multithreaded DLL /MD - OpenSSL defaults to this.
+ Debug Multithreaded DLL /MDd
+
+Note that debug and release libraries are NOT interchangeable. If you
+built OpenSSL with /MD your application must use /MD and cannot use /MDd.
* How do I read or write a DER encoded buffer using the ASN1 functions?
* Why doesn't my server application receive a client certificate?
Due to the TLS protocol definition, a client will only send a certificate,
-if explicitely asked by the server. Use the SSL_VERIFY_PEER flag of the
+if explicitly asked by the server. Use the SSL_VERIFY_PEER flag of the
SSL_CTX_set_verify() function to enable the use of client certificates.
+* Why does compilation fail due to an undefined symbol NID_uniqueIdentifier?
+
+For OpenSSL 0.9.7 the OID table was extended and corrected. In earlier
+versions, uniqueIdentifier was incorrectly used for X.509 certificates.
+The correct name according to RFC2256 (LDAP) is x500UniqueIdentifier.
+Change your code to use the new name when compiling against OpenSSL 0.9.7.
+
+
===============================================================================
projects / openssl.git / blobdiff