From 5d8b3a3ef2941b8822523742a0408ca6896aa65d Mon Sep 17 00:00:00 2001 From: Nicola Tuveri Date: Sat, 13 Jun 2020 17:29:09 +0300 Subject: Refactor BN_R_NO_INVERSE logic in internal functions Closes #12129 As described in https://github.com/openssl/openssl/issues/12129 the readability of the internal functions providing the two alternative implementations for `BN_mod_inverse()` is a bit lacking. Both these functions are now completely internal, so we have the flexibility needed to slightly improve readability and remove unnecessary NULL checks. The main changes here are: - rename `BN_mod_inverse_no_branch()` as `bn_mod_inverse_no_branch()`: this function is `static` so it is not even visible within the rest of libcrypto. By convention upcase prefixes are reserved for public functions. - remove `if (pnoinv == NULL)` checks in `int_bn_mod_inverse()`: this function is internal to the BN module and we can guarantee that all callers pass non-NULL arguments. - `bn_mod_inverse_no_branch()` takes an extra `int *pnoinv` argument, so that it can signal if no inverse exists for the given inputs: in this way the caller is in charge of raising `BN_R_NO_INVERSE` as it is the case for the non-consttime implementation of `int_bn_mod_inverse()`. - `BN_mod_inverse()` is a public function and must guarantee that the internal functions providing the actual implementation receive valid arguments. If the caller passes a NULL `BN_CTX` we create a temporary one for internal use. - reorder function definitions in `crypto/bn/bn_gcd.c` to avoid forward declaration of `static` functions (in preparation for inlining). - inline `bn_mod_inverse_no_branch()`. Reviewed-by: Tomas Mraz (Merged from https://github.com/openssl/openssl/pull/12142) --- crypto/err/openssl.txt | 1 - 1 file changed, 1 deletion(-) (limited to 'crypto/err') diff --git a/crypto/err/openssl.txt b/crypto/err/openssl.txt index 8fd805cd9c..40148e8a2c 100644 --- a/crypto/err/openssl.txt +++ b/crypto/err/openssl.txt @@ -221,7 +221,6 @@ BN_F_BN_MOD_EXP_MONT_WORD:117:BN_mod_exp_mont_word BN_F_BN_MOD_EXP_RECP:125:BN_mod_exp_recp BN_F_BN_MOD_EXP_SIMPLE:126:BN_mod_exp_simple BN_F_BN_MOD_INVERSE:110:BN_mod_inverse -BN_F_BN_MOD_INVERSE_NO_BRANCH:139:BN_mod_inverse_no_branch BN_F_BN_MOD_LSHIFT_QUICK:119:BN_mod_lshift_quick BN_F_BN_MOD_SQRT:121:BN_mod_sqrt BN_F_BN_MONT_CTX_NEW:149:BN_MONT_CTX_new -- cgit v1.2.3