diff --git a/tinycrypt/ecc.c b/tinycrypt/ecc.c index 1328ea2d1..2e99bc9c0 100644 --- a/tinycrypt/ecc.c +++ b/tinycrypt/ecc.c @@ -1610,10 +1610,13 @@ static void EccPoint_mult(uECC_word_t * result, const uECC_word_t * point, static uECC_word_t regularize_k(const uECC_word_t * const k, uECC_word_t *k0, uECC_word_t *k1) { + wordcount_t num_n_words = NUM_ECC_WORDS; bitcount_t num_n_bits = NUM_ECC_BITS; + uECC_word_t carry = uECC_vli_add(k0, k, curve_n) || - uECC_vli_testBit(k0, num_n_bits); + (num_n_bits < ((bitcount_t)num_n_words * uECC_WORD_SIZE * 8) && + uECC_vli_testBit(k0, num_n_bits)); uECC_vli_add(k1, k0, curve_n);