-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?
-* I've called <some function> 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 <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 0.9.5a 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 <URL:
-ftp://ftp.openssl.org/snapshot/>, or get it by anonymous CVS access.
-
-
-* Where is the documentation?
-
-OpenSSL is a library that provides cryptographic functionality to
-applications such as secure web servers. Be sure to read the
-documentation of the application you want to use. The INSTALL file
-explains how to install this library.
-
-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
-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/>.
-
-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
-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 resources
-help, but please note that it reflects the obsolete version SSLeay
-0.6.6.
-
-
-* How can I contact the OpenSSL developers?
-
-The README file describes how to submit bug reports and patches to
-OpenSSL. Information on the OpenSSL mailing lists is available from
-<URL: http://www.openssl.org>.
-
-
-* Do I need patent licenses to use OpenSSL?
-
-The patents section of the README file lists patents that may apply to
-you if you want to use OpenSSL. For information on intellectual
-property rights, please consult a lawyer. The OpenSSL team does not
-offer legal advice.
-
-You can configure OpenSSL so as not to use RC5 and IDEA by using
- ./config no-rc5 no-idea
-
-Until the RSA patent expires, U.S. users may want to use
- ./config no-rc5 no-idea no-rsa
-
-Please note that you will *not* be able to communicate with most of
-the popular web browsers without RSA support.
-
-
-* Is OpenSSL thread-safe?
-
-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 is described in the threads(3) manpage.
-
-
-* Why do I get a "PRNG not seeded" error message?
-
-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.
-
-On systems without /dev/urandom, it is a good idea to use the Entropy
-Gathering Demon; see the RAND_egd() manpage for details.
-
-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 to OpenSSL 0.9.5 users: The command "openssl rsa" in version
-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 version 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.
-
-
-* I've called <some function> 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.
-
-
-* 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 <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 -----
+The FAQ is now maintained on the web:
+ https://www.openssl.org/docs/faq.html
projects / openssl.git / blobdiff