X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=FAQ;h=0281b4c4c7423c2c2c1462afab4fc4d9029383cc;hp=259ea4bc41bdc666a1a830904ce061293df7a74c;hb=1fc6d41bf662a8e441226b73ad36d8fa24aaa51d;hpb=35feed50f0b495dcd9ca65afe85fa66606b50084

diff --git a/FAQ b/FAQ
index 259ea4bc41..0281b4c4c7 100644
--- a/FAQ
+++ b/FAQ
@@ -8,6 +8,7 @@ OpenSSL  -  Frequently Asked Questions
 * 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?
 
 [LEGAL] Legal questions
 
@@ -17,6 +18,7 @@ OpenSSL  -  Frequently Asked 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?
@@ -32,7 +34,7 @@ OpenSSL  -  Frequently Asked Questions
 * 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 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++?
 
@@ -47,6 +49,7 @@ OpenSSL  -  Frequently Asked Questions
 * Why do I get errors about unknown algorithms?
 * 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?
 
 ===============================================================================
 
@@ -55,7 +58,7 @@ OpenSSL  -  Frequently Asked Questions
 * 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 0.9.6b was released on July 9th, 2001.
 
 In addition to the current stable release, you can also access daily
 snapshots of the OpenSSL development version at <URL:
@@ -119,6 +122,12 @@ A number of Linux and *BSD distributions include OpenSSL.
 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.
 
 [LEGAL] =======================================================================
 
@@ -144,7 +153,7 @@ holders claim that you infringe on their rights if you use OpenSSL with
 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
@@ -160,6 +169,7 @@ 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.
+(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
@@ -169,13 +179,30 @@ 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.
+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
+details.  Starting with version 0.9.7, OpenSSL will automatically look
+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 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.
 
-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.
 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
@@ -183,11 +210,6 @@ OpenSSL command line tools. Applications using the OpenSSL library
 provide their own configuration options to specify the entropy source,
 please check out the documentation coming the with application.
 
-[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.]
-
 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
@@ -196,6 +218,18 @@ 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?
 
 Check out the CA.pl(1) manual page. This provides a simple wrapper round
@@ -270,7 +304,7 @@ there is little point presenting a certificate which the server will
 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
@@ -332,9 +366,9 @@ 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 True64 Unix?
+* 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
@@ -521,5 +555,12 @@ requiring a bi-directional message exchange; both SSL_read() and
 SSL_write() will try to continue any pending handshake.
 
 
+* Why doesn't my server application receive a client certificate?
+
+Due to the TLS protocol definition, a client will only send a certificate,
+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.
+
+
 ===============================================================================