openbsd/src/lib/libcrypto/man/BN_set_flags.3, branch OPENBSD_6_8_BASEA mirror of https://github.com/libressl/openbsd.git
https://git.lua4.win/openbsd/atom?h=OPENBSD_6_8_BASE2018-04-29T15:58:21+00:00In view of the recent BN_FLG_CONSTTIME vulnerabilities in OpenSSL,2018-04-29T15:58:21+00:00schwarze2018-04-29T15:58:21+00:00urn:sha1:0cafa356a8c4c7fcd0ceea551f687c5d7fbef24e
carefully document constant time vs. non-constant time operation
of BN_div(3), BN_mod_exp(3), and BN_mod_inverse(3).
Until the work that is required on the ill-designed BN_exp(3) and
BN_gcd(3) interfaces can be undertaken, also document the imperfections
in their behaviour, for now. Finally, mention BN_mod_exp(3) behaviour
for even moduli.
Delete the vague statement about some functions automatically
setting BN_FLG_CONSTTIME. It created a false sense of security.
Do not rely on it: not all relevant functions do that.
Topic brought up by beck@, significant feedback and OK jsing@.
crypto HISTORY up to SSLeay 0.9.1; researched from OpenSSL git2018-03-21T09:03:49+00:00schwarze2018-03-21T09:03:49+00:00urn:sha1:9c6b7656d1237ca414073bcf0955561c2e9e90ccDocument BN_set_flags(3) and BN_get_flags(3).2017-01-30T01:29:31+00:00schwarze2017-01-30T01:29:31+00:00urn:sha1:19dcc2c9146afbb7e7ee92dd56ef7f469c46c87e
jsing@ confirmed that these macros are public and worth documenting.