diff options
Diffstat (limited to 'src/secp256k1/src/scalar_low_impl.h')
| -rw-r--r-- | src/secp256k1/src/scalar_low_impl.h | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/src/secp256k1/src/scalar_low_impl.h b/src/secp256k1/src/scalar_low_impl.h index b79cf1ff6c..a615ec074b 100644 --- a/src/secp256k1/src/scalar_low_impl.h +++ b/src/secp256k1/src/scalar_low_impl.h @@ -48,14 +48,17 @@ static void secp256k1_scalar_cadd_bit(secp256k1_scalar *r, unsigned int bit, int } static void secp256k1_scalar_set_b32(secp256k1_scalar *r, const unsigned char *b32, int *overflow) { - const int base = 0x100 % EXHAUSTIVE_TEST_ORDER; int i; + int over = 0; *r = 0; for (i = 0; i < 32; i++) { - *r = ((*r * base) + b32[i]) % EXHAUSTIVE_TEST_ORDER; + *r = (*r * 0x100) + b32[i]; + if (*r >= EXHAUSTIVE_TEST_ORDER) { + over = 1; + *r %= EXHAUSTIVE_TEST_ORDER; + } } - /* just deny overflow, it basically always happens */ - if (overflow) *overflow = 0; + if (overflow) *overflow = over; } static void secp256k1_scalar_get_b32(unsigned char *bin, const secp256k1_scalar* a) { |