diff options
| author | Tomas Mraz <tomas@openssl.org> | 2022-11-03 13:48:55 +0100 |
|---|---|---|
| committer | Tomas Mraz <tomas@openssl.org> | 2023-01-09 08:32:29 +0100 |
| commit | df073dd603cedfa3599ded07c3fefe3f166d5808 (patch) | |
| tree | 161c3dc924499347ec0773d5d3b8778b929b9393 /crypto/bn | |
| parent | 9470c182834d26f9792fade2486e6fb7f8213c7c (diff) | |
rsaz_exp_x2.c: Avoid potential undefined behavior with strict aliasing
Fixes #19584
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19597)
(cherry picked from commit 9506a2e274c643b94a2c265019ea9288f99a521a)
Diffstat (limited to 'crypto/bn')
| -rw-r--r-- | crypto/bn/rsaz_exp_x2.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/crypto/bn/rsaz_exp_x2.c b/crypto/bn/rsaz_exp_x2.c index 95a1380f8f..fb96d67743 100644 --- a/crypto/bn/rsaz_exp_x2.c +++ b/crypto/bn/rsaz_exp_x2.c @@ -556,9 +556,13 @@ static void to_words52(BN_ULONG *out, int out_len, in_str = (uint8_t *)in; for (; in_bitsize >= (2 * DIGIT_SIZE); in_bitsize -= (2 * DIGIT_SIZE), out += 2) { - out[0] = (*(uint64_t *)in_str) & DIGIT_MASK; + uint64_t digit; + + memcpy(&digit, in_str, sizeof(digit)); + out[0] = digit & DIGIT_MASK; in_str += 6; - out[1] = ((*(uint64_t *)in_str) >> 4) & DIGIT_MASK; + memcpy(&digit, in_str, sizeof(digit)); + out[1] = (digit >> 4) & DIGIT_MASK; in_str += 7; out_len -= 2; } @@ -617,9 +621,13 @@ static void from_words52(BN_ULONG *out, int out_bitsize, const BN_ULONG *in) for (; out_bitsize >= (2 * DIGIT_SIZE); out_bitsize -= (2 * DIGIT_SIZE), in += 2) { - (*(uint64_t *)out_str) = in[0]; + uint64_t digit; + + digit = in[0]; + memcpy(out_str, &digit, sizeof(digit)); out_str += 6; - (*(uint64_t *)out_str) ^= in[1] << 4; + digit = digit >> 48 | in[1] << 4; + memcpy(out_str, &digit, sizeof(digit)); out_str += 7; } |