yuzu/mbedtls
1
0
Fork 0
mirror of https://github.com/yuzu-emu/mbedtls.git synced 2025-05-31 12:47:12 +00:00
Code Issues Packages Projects Releases Wiki Activity

Hardcode numwords in vli_cmp

Browse source
This commit is contained in:
Manuel Pégourié-Gonnard 2019-11-04 14:43:35 +01:00
parent 129b42ea2e
commit 2cb3eea922
3 changed files with 5 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
include/tinycrypt/ecc.h
View file

@ -320,8 +320,7 @@ uECC_word_t EccPoint_isZero(const uECC_word_t *point, uECC_Curve curve);
* @param num_words IN -- number of words * @param num_words IN -- number of words
* @return the sign of left - right * @return the sign of left - right
*/ */
cmpresult_t uECC_vli_cmp(const uECC_word_t *left, const uECC_word_t *right, cmpresult_t uECC_vli_cmp(const uECC_word_t *left, const uECC_word_t *right);
wordcount_t num_words);
/* /*
* @brief computes sign of left - right, not in constant time. * @brief computes sign of left - right, not in constant time.

8
tinycrypt/ecc.c
View file

@ -226,13 +226,11 @@ static uECC_word_t uECC_vli_add(uECC_word_t *result, const uECC_word_t *left,
return carry; return carry;
} }
cmpresult_t uECC_vli_cmp(const uECC_word_t *left, const uECC_word_t *right, cmpresult_t uECC_vli_cmp(const uECC_word_t *left, const uECC_word_t *right)
wordcount_t num_words)
{ {
uECC_word_t tmp[NUM_ECC_WORDS]; uECC_word_t tmp[NUM_ECC_WORDS];
uECC_word_t neg = !!uECC_vli_sub(tmp, left, right); uECC_word_t neg = !!uECC_vli_sub(tmp, left, right);
uECC_word_t equal = uECC_vli_isZero(tmp); uECC_word_t equal = uECC_vli_isZero(tmp);
(void) num_words;
return (!equal - 2 * neg); return (!equal - 2 * neg);
} }
@ -1039,7 +1037,7 @@ int uECC_generate_random_int(uECC_word_t *random, const uECC_word_t *top,
random[num_words - 1] &= random[num_words - 1] &=
mask >> ((bitcount_t)(num_words * uECC_WORD_SIZE * 8 - num_bits)); mask >> ((bitcount_t)(num_words * uECC_WORD_SIZE * 8 - num_bits));
if (!uECC_vli_isZero(random) && if (!uECC_vli_isZero(random) &&
uECC_vli_cmp(top, random, num_words) == 1) { uECC_vli_cmp(top, random) == 1) {
return 1; return 1;
} }
} }
@ -1109,7 +1107,7 @@ int uECC_compute_public_key(const uint8_t *private_key, uint8_t *public_key,
return 0; return 0;
} }
if (uECC_vli_cmp(curve->n, _private, BITS_TO_WORDS(curve->num_n_bits)) != 1) { if (uECC_vli_cmp(curve->n, _private) != 1) {
return 0; return 0;
} }

2
tinycrypt/ecc_dsa.c
View file

@ -121,7 +121,7 @@ int uECC_sign_with_k(const uint8_t *private_key, const uint8_t *message_hash,
/* Make sure 0 < k < curve_n */ /* Make sure 0 < k < curve_n */
if (uECC_vli_isZero(k) || if (uECC_vli_isZero(k) ||
uECC_vli_cmp(curve->n, k, num_n_words) != 1) { uECC_vli_cmp(curve->n, k) != 1) {
return 0; return 0;
} }