Fix divide by 0 finding (GH #855)

I'm not sure which tool is producing this finding. I am pretty sure it is a false positive, but clear it for the sake of dark and silent cockpits

1 files changed, 4 insertions, 0 deletions

diff --git a/pwdbased.h b/pwdbased.h
index a27550a7..e2a01464 100644
--- a/pwdbased.h
+++ b/pwdbased.h
@@ -245,7 +245,11 @@ size_t PKCS5_PBKDF2_HMAC<T>::DeriveKey(byte *derived, size_t derivedLen, byte pu
 	// Business logic

 	if (!iterations) { iterations = 1; }

 

+	// DigestSize check due to https://github.com/weidai11/cryptopp/issues/855

 	HMAC<T> hmac(secret, secretLen);

+	if (hmac.DigestSize() == 0)

+		throw InvalidArgument("PKCS5_PBKDF2_HMAC: DigestSize cannot be 0");

+

 	SecByteBlock buffer(hmac.DigestSize());

 	ThreadUserTimer timer;