Earlier OpenSSL versions printed prompts to stderr.

[openssl.git] / FAQ

diff --git a/FAQ b/FAQ
index 019c016bebcacdf6d3c36b37fb86117042d08a1d..2043607c935811cfae82ce16c06c918a7a4790f0 100644 (file)
--- a/FAQ
+++ b/FAQ
@@ -17,6 +17,7 @@ OpenSSL  -  Frequently Asked Questions
 [USER] Questions on using the OpenSSL applications
 
 * Why do I get a "PRNG not seeded" error message?
 [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 do I create certificates or certificate requests?
 * Why can't I create certificate requests?
 * Why does <SSL program> fail with a certificate verify error?


@@ -161,6 +162,7 @@ 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.
 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
 
 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


@@ -176,10 +178,24 @@ 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.
 
 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
 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


@@ -195,6 +211,18 @@ versions.  However, be warned that /dev/random is usually a blocking
 device, which may have some effects on OpenSSL.
 
 
 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
 * How do I create certificates or certificate requests?
 
 Check out the CA.pl(1) manual page. This provides a simple wrapper round