diff --git a/tests/api.c b/tests/api.c index 15c3ec4c3..cd8c06951 100644 --- a/tests/api.c +++ b/tests/api.c @@ -19594,6 +19594,9 @@ static int test_wc_DsaSignVerify (void) mp_free(&key.q); mp_init(&key.q); AssertIntEQ(wc_DsaSign(hash, signature, &key, &rng), BAD_FUNC_ARG); + + mp_set_int(&key.q, 1); + AssertIntEQ(wc_DsaSign(hash, signature, &key, &rng), BAD_FUNC_ARG); #endif if (wc_FreeRng(&rng) && ret == 0) { diff --git a/wolfcrypt/src/dsa.c b/wolfcrypt/src/dsa.c index adee05616..7e6cf17bc 100644 --- a/wolfcrypt/src/dsa.c +++ b/wolfcrypt/src/dsa.c @@ -762,6 +762,12 @@ int wc_DsaSign(const byte* digest, byte* out, DsaKey* key, WC_RNG* rng) break; } + /* if q-1 is 0 or smaller, k will never end up being less than it */ + if (mp_iszero(qMinus1) || mp_isneg(qMinus1)) { + ret = BAD_FUNC_ARG; + break; + } + do { /* Step 4: generate k */ if ((ret = wc_RNG_GenerateBlock(rng, buffer, halfSz))) {