diff options
Diffstat (limited to 'ext/lib/crypto/tinycrypt/source/ecc.c')
| -rw-r--r-- | ext/lib/crypto/tinycrypt/source/ecc.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/ext/lib/crypto/tinycrypt/source/ecc.c b/ext/lib/crypto/tinycrypt/source/ecc.c index 357139b9b..bfe6c5f13 100644 --- a/ext/lib/crypto/tinycrypt/source/ecc.c +++ b/ext/lib/crypto/tinycrypt/source/ecc.c @@ -97,7 +97,9 @@ static void vli_clear(uint32_t *p_vli) } } -/* Returns nonzero if bit p_bit of p_vli is set. */ +/* Returns nonzero if bit p_bit of p_vli is set. + * It is assumed that the value provided in 'bit' is within + * the boundaries of the word-array 'p_vli'.*/ static uint32_t vli_testBit(uint32_t *p_vli, uint32_t p_bit) { return (p_vli[p_bit / 32] & (1 << (p_bit % 32))); @@ -235,7 +237,7 @@ static void vli_square(uint32_t *p_result, uint32_t *p_left) } /* Computes p_result = p_product % curve_p using Barrett reduction. */ -static void vli_mmod_barrett(uint32_t *p_result, uint32_t *p_product, +void vli_mmod_barrett(uint32_t *p_result, uint32_t *p_product, uint32_t *p_mod, uint32_t *p_barrett) { uint32_t i; @@ -547,7 +549,7 @@ void EccPoint_add(EccPointJacobi *P1, EccPointJacobi *P2) * * p_result = p_scalar * p_point. */ -void EccPoint_mult(EccPointJacobi *p_result, EccPoint *p_point, uint32_t *p_scalar) +void EccPoint_mult_safe(EccPointJacobi *p_result, EccPoint *p_point, uint32_t *p_scalar) { int32_t i; @@ -568,6 +570,25 @@ void EccPoint_mult(EccPointJacobi *p_result, EccPoint *p_point, uint32_t *p_scal } } +/* Ellptic curve scalar multiplication with result in Jacobi coordinates */ +/* p_result = p_scalar * p_point */ +void EccPoint_mult_unsafe(EccPointJacobi *p_result, EccPoint *p_point, uint32_t *p_scalar) +{ + int i; + EccPointJacobi p_point_jacobi; + EccPoint_fromAffine(p_result, p_point); + EccPoint_fromAffine(&p_point_jacobi, p_point); + + for(i = vli_numBits(p_scalar) - 2; i >= 0; i--) + { + EccPoint_double(p_result); + if (vli_testBit(p_scalar, i)) + { + EccPoint_add(p_result, &p_point_jacobi); + } + } +} + /* -------- Conversions between big endian and little endian: -------- */ void ecc_bytes2native(uint32_t p_native[NUM_ECC_DIGITS], |