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.
-(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
-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.
+device" (/dev/urandom or /dev/random) that serves this purpose.
+All OpenSSL versions try to use /dev/urandom by default; starting with
+version 0.9.7, OpenSSL also tries /dev/random is /dev/urandom is not
+available.
+
+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 number generator has not been
+seeded with at least 128 bits of randomness. If this error occurs and
+is not discussed in the documentation of the application you are
+using, please contact the author of that application; 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.
+
+If you are using Solaris 8, you can add /dev/urandom and /dev/random
+devices by installing patch 112438 (Sparc) or 112439 (x86), which are
+available via the Patchfinder at <URL: http://sunsolve.sun.com>
+(Solaris 9 includes these devices by default). For /dev/random support
+for earlier Solaris versions, see Sun's statement at
+<URL: http://sunsolve.sun.com/pub-cgi/retrieve.pl?doc=fsrdb/27606&zone_32=SUNWski>
+(the SUNWski package is available in patch 105710).
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
provide their own configuration options to specify the entropy source,
please check out the documentation coming the with application.
-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
-$RANDFILE. There are probably similar patches for the other Solaris
-versions. An official statement from Sun with respect to /dev/random
-support can be found at
- http://sunsolve.sun.com/pub-cgi/retrieve.pl?doc=fsrdb/27606&zone_32=SUNWski
-However, be warned that /dev/random is usually a blocking device, which
-may have some effects on OpenSSL.
-A third party /dev/random solution for Solaris is available at
- http://www.cosy.sbg.ac.at/~andi/
-
* Why do I get an "unable to write 'random state'" error message?