Folks: The buildbot for the Tahoe-LAFS project runs CPython under valgrind on Fedora, and valgrind emits warnings like this:
==30127== Conditional jump or move depends on uninitialised value(s) ==30127== at 0x4C2AD01: bcmp (mc_replace_strmem.c:889) ==30127== by 0xC1D1646: fips_get_entropy (fips_drbg_lib.c:166) ==30127== by 0xC1D1D6E: FIPS_drbg_instantiate (fips_drbg_lib.c:234) ==30127== by 0xC15F590: RAND_init_fips (rand_lib.c:286) ==30127== by 0xC0F54D3: OPENSSL_init_library (o_init.c:106) ==30127== by 0xBE76AF8: SSL_library_init (ssl_algs.c:68) ==30127== by 0xBC2B39D: init_hashlib (in /usr/lib64/python2.7/lib-dynload/_hashlib.so) ==30127== by 0x4F1DB00: _PyImport_LoadDynamicModule (in /usr/lib64/libpython2.7.so.1.0) You can see the full output from such a buildbot run here: https://tahoe-lafs.org/buildbot-pycryptopp/builders/Ruben%20Fedora%20syslib/builds/58/steps/test%20valgrind/logs/valgrind Here is information about the versions of software involved: https://tahoe-lafs.org/buildbot-pycryptopp/builders/Ruben%20Fedora%20syslib/builds/58/steps/show-tool-versions/logs/stdio The owner of the buildslave machine says that the openssl package was "openssl-1.0.1-0.1.beta2.fc17.x86_64". Not having looked closer, I assume this is just a case of using uninitialized memory as part of the initialization of the PRNG. Accordingly, I wrote suppressions stanzas for our valgrind suppressions file (https://tahoe-lafs.org/trac/pycryptopp/browser/git/misc/coding_helpers/python.supp ), which made the warnings go away. Appended are the suppression expressions. If there's any interest, I could write a patch for openssl to zero out memory before using it in the PRNG. I assume that you have discussed that before now and decided against it, but if you want a patch that does that, let me know. I opened this ticket on launchpad.net to track the handling of this issue in various projects such as openssl, pycryptopp, CPython, valgrind, and Fedora: https://bugs.launchpad.net/pycryptopp/+bug/944585 Regards, Zooko # generated on buildbot.rubenkerkhof.com, which had, according to Ruben # Fedora's package "openssl-1.0.1-0.1.beta2.fc17.x86_64" { buildbot.rubenkerkhof.com cond fips openssl 1 Memcheck:Cond fun:bcmp fun:fips_get_entropy fun:FIPS_drbg_instantiate fun:RAND_init_fips fun:OPENSSL_init_library fun:SSL_library_init fun:init_hashlib } { buildbot.rubenkerkhof.com cond fips openssl 2 Memcheck:Cond fun:fips_get_entropy fun:FIPS_drbg_instantiate fun:RAND_init_fips fun:OPENSSL_init_library fun:SSL_library_init fun:init_hashlib } { buildbot.rubenkerkhof.com val _x86_64_AES_encrypt_compact Memcheck:Value8 fun:_x86_64_AES_encrypt_compact fun:AES_encrypt } ______________________________________________________________________ OpenSSL Project http://www.openssl.org Development Mailing List openssl-dev@openssl.org Automated List Manager majord...@openssl.org
