OpenSSL - Frequently Asked Questions
--------------------------------------
+* Which is the current version of OpenSSL?
* Where is the documentation?
* How can I contact the OpenSSL developers?
* Do I need patent licenses to use OpenSSL?
* Is OpenSSL thread-safe?
* Why do I get a "PRNG not seeded" error message?
+* Why does the linker complain about undefined symbols?
+* Where can I get a compiled version of OpenSSL?
+* I've compiled a program under Windows and it crashes: why?
+* Why do I get errors about unknown algorithms?
+* 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 create DSA certificates?
+* Why can't I make an SSL connection using a DSA certificate?
+* Why can't the OpenSSH configure script detect OpenSSL?
+
+
+* Which is the current version of OpenSSL?
+
+The current version is available from <URL: http://www.openssl.org>.
+OpenSSL 0.9.5 was released on February 28th, 2000.
+
+In addition to the current stable release, you can also access daily
+snapshots of the OpenSSL development version at <URL:
+ftp://ftp.openssl.org/snapshot/>, or get it by anonymous CVS access.
* Where is the documentation?
predecessor, at <URL: http://www.columbia.edu/~ariel/ssleay/>. Much
of this still applies to OpenSSL.
+There is some documentation about certificate extensions and PKCS#12
+in doc/openssl.txt
+
The original SSLeay documentation is included in OpenSSL as
-doc/ssleay.txt. It may be useful when none of the other ressources
+doc/ssleay.txt. It may be useful when none of the other resources
help, but please note that it reflects the obsolete version SSLeay
0.6.6.
* Is OpenSSL thread-safe?
-Yes. On Windows and many Unix systems, OpenSSL automatically uses the
-multi-threaded versions of the standard libraries. If your platform
-is not one of these, consult the INSTALL file.
+Yes (with limitations: an SSL connection may not concurrently be used
+by multiple threads). On Windows and many Unix systems, OpenSSL
+automatically uses the multi-threaded versions of the standard
+libraries. If your platform is not one of these, consult the INSTALL
+file.
Multi-threaded applications must provide two callback functions to
-OpenSSL. This will be described in the threads(3) manpage. [That
-page has not been written yet. Please read the "threads.doc" section
-of doc/ssleay.txt instead.]
+OpenSSL. This is described in the threads(3) manpage.
* Why do I get a "PRNG not seeded" error message?
application you are using. It is likely that it never worked
correctly. OpenSSL 0.9.5 makes the error visible by refusing to
perform potentially insecure encryption.
+
+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.
+Note that the command "openssl rsa" in OpenSSL 0.9.5 does not do this
+and will fail on systems without /dev/urandom when trying to
+password-encrypt an RSA key! This is a bug in the library;
+try a later snaphost instead.
+
+
+* Why does the linker complain about undefined symbols?
+
+Maybe the compilation was interrupted, and make doesn't notice that
+something is missing. Run "make clean; make".
+
+If you used ./Configure instead of ./config, make sure that you
+selected the right target. File formats may differ slightly between
+OS versions (for example sparcv8/sparcv9, or a.out/elf).
+
+In case you get errors about the following symbols, use the config
+option "no-asm", as described in INSTALL:
+
+ BF_cbc_encrypt, BF_decrypt, BF_encrypt, CAST_cbc_encrypt,
+ CAST_decrypt, CAST_encrypt, RC4, RC5_32_cbc_encrypt, RC5_32_decrypt,
+ RC5_32_encrypt, bn_add_words, bn_div_words, bn_mul_add_words,
+ bn_mul_comba4, bn_mul_comba8, bn_mul_words, bn_sqr_comba4,
+ bn_sqr_comba8, bn_sqr_words, bn_sub_words, des_decrypt3,
+ des_ede3_cbc_encrypt, des_encrypt, des_encrypt2, des_encrypt3,
+ des_ncbc_encrypt, md5_block_asm_host_order, sha1_block_asm_data_order
+
+If none of these helps, you may want to try using the current snapshot.
+If the problem persists, please submit a bug report.
+
+
+* Where can I get a compiled version of OpenSSL?
+
+Some applications that use OpenSSL are distributed in binary form.
+When using such an application, you don't need to install OpenSSL
+yourself; the application will include the required parts (e.g. DLLs).
+
+If you want to install OpenSSL on a Windows system and you don't have
+a C compiler, read the "Mingw32" section of INSTALL.W32 for information
+on how to obtain and install the free GNU C compiler.
+
+A number of Linux and *BSD distributions include OpenSSL.
+
+
+* 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.
+
+
+* 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.
+
+
+* How do I create certificates or certificate requests?
+
+Check out the CA.pl(1) manual page. This provides a simple wrapper round
+the 'req', 'verify', 'ca' and 'pkcs12' utilities. For finer control check
+out the manual pages for the individual utilities and the certificate
+extensions documentation (currently in doc/openssl.txt).
+
+
+* Why can't I create certificate requests?
+
+You typically get the error:
+
+ unable to find 'distinguished_name' in config
+ problems making Certificate Request
+
+This is because it can't find the configuration file. Check out the
+DIAGNOSTICS section of req(1) for more information.
+
+
+* Why does <SSL program> fail with a certificate verify error?
+
+This problem is usually indicated by log messages saying something like
+"unable to get local issuer certificate" or "self signed certificate".
+When a certificate is verified its root CA must be "trusted" by OpenSSL
+this typically means that the CA certificate must be placed in a directory
+or file and the relevant program configured to read it. The OpenSSL program
+'verify' behaves in a similar way and issues similar error messages: check
+the verify(1) program manual page for more information.
+
+
+* How can I create DSA certificates?
+
+Check the CA.pl(1) manual page for a DSA certificate example.
+
+
+* Why can't I make an SSL connection to a server using a DSA certificate?
+
+Typically you'll see a message saying there are no shared ciphers when
+the same setup works fine with an RSA certificate. There are two possible
+causes. The client may not support connections to DSA servers most web
+browsers only support connections to servers supporting RSA cipher suites.
+The other cause is that a set of DH parameters has not been supplied to
+the server. DH parameters can be created with the dhparam(1) command and
+loaded using the SSL_CTX_set_tmp_dh() for example: check the source to
+s_server in apps/s_server.c for an example.
+
+
+* Why can't the OpenSSH configure script detect OpenSSL?
+
+There is a problem with OpenSSH 1.2.2p1, in that the configure script
+can't find the installed OpenSSL libraries. The problem is actually
+a small glitch that is easily solved with the following patch to be
+applied to the OpenSSH distribution:
+
+----- snip:start -----
+--- openssh-1.2.2p1/configure.in.orig Thu Mar 23 18:56:58 2000
++++ openssh-1.2.2p1/configure.in Thu Mar 23 18:55:05 2000
+@@ -152,10 +152,10 @@
+ AC_MSG_CHECKING([for OpenSSL/SSLeay directory])
+ for ssldir in "" $tryssldir /usr /usr/local/openssl /usr/lib/openssl /usr/local/ssl /usr/lib/ssl /usr/local /usr/pkg /opt /opt/openssl ; do
+ if test ! -z "$ssldir" ; then
+- LIBS="$saved_LIBS -L$ssldir"
++ LIBS="$saved_LIBS -L$ssldir/lib"
+ CFLAGS="$CFLAGS -I$ssldir/include"
+ if test "x$need_dash_r" = "x1" ; then
+- LIBS="$LIBS -R$ssldir"
++ LIBS="$LIBS -R$ssldir/lib"
+ fi
+ fi
+ LIBS="$LIBS -lcrypto"
+--- openssh-1.2.2p1/configure.orig Thu Mar 23 18:55:02 2000
++++ openssh-1.2.2p1/configure Thu Mar 23 18:57:08 2000
+@@ -1890,10 +1890,10 @@
+ echo "configure:1891: checking for OpenSSL/SSLeay directory" >&5
+ for ssldir in "" $tryssldir /usr /usr/local/openssl /usr/lib/openssl /usr/local/ssl /usr/lib/ssl /usr/local /usr/pkg /opt /opt/openssl ; do
+ if test ! -z "$ssldir" ; then
+- LIBS="$saved_LIBS -L$ssldir"
++ LIBS="$saved_LIBS -L$ssldir/lib"
+ CFLAGS="$CFLAGS -I$ssldir/include"
+ if test "x$need_dash_r" = "x1" ; then
+- LIBS="$LIBS -R$ssldir"
++ LIBS="$LIBS -R$ssldir/lib"
+ fi
+ fi
+ LIBS="$LIBS -lcrypto"
+----- snip:end -----
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