From: Bodo Möller Date: Tue, 4 Feb 2003 12:26:30 +0000 (+0000) Subject: Update PRNG entry: X-Git-Tag: OpenSSL_0_9_6i~7 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=ac3b89d8e5abe84fbae0102a05ed86083123faf7;p=oweals%2Fopenssl.git Update PRNG entry: - OpenSSL version differences - Sun /dev/urandom patch information --- diff --git a/FAQ b/FAQ index 976f3197dd..27d6cbc97d 100644 --- a/FAQ +++ b/FAQ @@ -184,18 +184,30 @@ for permission to use their software with OpenSSL. 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 +(Solaris 9 includes these devices by default). For /dev/random support +for earlier Solaris versions, see Sun's statement at + +(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 @@ -228,18 +240,6 @@ 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. -For Solaris 2.6, Tim Nibbe 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?