X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=FAQ;h=ff5ea089d3a9f09c9ecd28de340d19dc7cad85ed;hp=78018fc8fed88b546ed313b7115a52a8e1f4095c;hb=abc9400e100632760727d150946f5269a0a5227b;hpb=299e7c91459b2ed74d786e3ed12a9a48bbd929f1 diff --git a/FAQ b/FAQ index 78018fc8fe..ff5ea089d3 100644 --- a/FAQ +++ b/FAQ @@ -9,12 +9,24 @@ OpenSSL - Frequently Asked Questions * 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? +* I've called and it fails, why? +* I just get a load of numbers for the error output, what do they mean? +* 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 fail with a certificate verify error? +* Why can I only use weak ciphers when I connect to a server using OpenSSL? +* How can I create DSA certificates? +* Why can't I make an SSL connection using a DSA certificate? +* How can I remove the passphrase on a private key? +* Why can't the OpenSSH configure script detect OpenSSL? * Which is the current version of OpenSSL? The current version is available from . -OpenSSL 0.9.5 was released on February 28th, 2000. +OpenSSL 0.9.5a was released on April 1st, 2000. In addition to the current stable release, you can also access daily snapshots of the OpenSSL development version at and it fails, why? + +Before submitting a report or asking in one of the mailing lists, you +should try to determine the cause. In particular, you should call +ERR_print_errors() or ERR_print_errors_fp() after the failed call +and see if the message helps. Note that the problem may occur earlier +than you think -- you should check for errors after every call where +it is possible, otherwise the actual problem may be hidden because +some OpenSSL functions clear the error state. + + +* I just get a load of numbers for the error output, what do they mean? + +The actual format is described in the ERR_print_errors() manual page. +You should call the function ERR_load_crypto_strings() before hand and +the message will be output in text form. If you can't do this (for example +it is a pre-compiled binary) you can use the errstr utility on the error +code itself (the hex digits after the second colon). + + +* 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 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. + + +* Why can I only use weak ciphers when I connect to a server using OpenSSL? + +This is almost certainly because you are using an old "export grade" browser +which only supports weak encryption. Upgrade your browser to support 128 bit +ciphers. + + +* 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 (including Netscape and MSIE) 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. + + +* How can I remove the passphrase on a private key? + +Firstly you should be really *really* sure you want to do this. Leaving +a private key unencrypted is a major security risk. If you decide that +you do have to do this check the EXAMPLES sections of the rsa(1) and +dsa(1) manual pages. + + +* 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 -----