From f67cbb74437842a0f88f84f43a0faa968ca77b35 Mon Sep 17 00:00:00 2001 From: Rich Salz Date: Mon, 8 Aug 2016 15:25:16 -0400 Subject: [PATCH] Add #defines for magic numbers in API. Binary- and backward-compatible. Just better. Reviewed-by: Matt Caswell (Merged from https://github.com/openssl/openssl/pull/1429) --- doc/crypto/BN_rand.pod | 17 +++++++++++------ include/openssl/bn.h | 9 +++++++++ 2 files changed, 20 insertions(+), 6 deletions(-) diff --git a/doc/crypto/BN_rand.pod b/doc/crypto/BN_rand.pod index c612c50a81..ba505e1e64 100644 --- a/doc/crypto/BN_rand.pod +++ b/doc/crypto/BN_rand.pod @@ -19,13 +19,18 @@ BN_rand, BN_pseudo_rand, BN_rand_range, BN_pseudo_rand_range - generate pseudo-r =head1 DESCRIPTION BN_rand() generates a cryptographically strong pseudo-random number of -B in length and stores it in B. If B is -1, the -most significant bit of the random number can be zero. If B is 0, -it is set to 1, and if B is 1, the two most significant bits of +B in length and stores it in B. +The value of B must be zero or greater. +The B parameters specifies +requirements on the most significant bit of the generated number. +If it is B, there is no constraint. +If it is B, the top bit must be one. +If it is B, the two most significant bits of the number will be set to 1, so that the product of two such random -numbers will always have 2*B length. If B is true, the -number will be odd. The value of B must be zero or greater. If B is -1 then B cannot also be 1. +numbers will always have 2*B length. +If B is B, the number will be odd; if it +is B it can be odd or even. +If B is 1 then B cannot also be B. BN_pseudo_rand() does the same, but pseudo-random numbers generated by this function are not necessarily unpredictable. They can be used for diff --git a/include/openssl/bn.h b/include/openssl/bn.h index 4dc2abd838..17bd52136c 100644 --- a/include/openssl/bn.h +++ b/include/openssl/bn.h @@ -82,6 +82,15 @@ extern "C" { void BN_set_flags(BIGNUM *b, int n); int BN_get_flags(const BIGNUM *b, int n); +/* Values for |top| in BN_rand() */ +#define BN_RAND_TOP_ANY -1 +#define BN_RAND_TOP_ONE 0 +#define BN_RAND_TOP_TWO 1 + +/* Values for |bottom| in BN_rand() */ +#define BN_RAND_BOTTOM_ANY 0 +#define BN_RAND_BOTTOM_ODD 1 + /* * get a clone of a BIGNUM with changed flags, for *temporary* use only (the * two BIGNUMs cannot be used in parallel!). Also only for *read only* use. The -- 2.25.1