a possible fix for TAINTED_SCALAR coverity issues

Signed-off-by: Mahdi Varasteh <varasteh@amnesh.ir>

ospfd/ospf_auth.c

@@ -157,7 +157,9 @@ static int ospf_auth_check_md5_digest(struct ospf_interface *oi,
 	unsigned char digest[OSPF_AUTH_MD5_SIZE];
 	struct ospf_neighbor *nbr;
 	struct crypt_key *ck = NULL;
-	uint16_t length = ntohs(ospfh->length);
+	unsigned int length = ntohs(ospfh->length);
+
+	assert(length <= UINT32_MAX); /* for coverity's sake */
 
 	if (key == NULL) {
 		ck = ospf_crypt_key_lookup(OSPF_IF_PARAM(oi, auth_crypt),
@@ -222,22 +224,21 @@ static int ospf_auth_check_md5_digest(struct ospf_interface *oi,
 static int ospf_auth_make_md5_digest(struct ospf_interface *oi,
 				     struct ospf_packet *op, struct key *key)
 {
-	void *ibuf;
-	struct ospf_header *ospfh;
+	void *ibuf = STREAM_DATA(op->s);
+	struct ospf_header *ospfh = (struct ospf_header *)ibuf;
 	unsigned char digest[OSPF_AUTH_MD5_SIZE];
-	uint16_t length;
+	unsigned int length = ntohs(ospfh->length);
 #ifdef CRYPTO_OPENSSL
 	EVP_MD_CTX *ctx;
 #elif CRYPTO_INTERNAL
 	MD5_CTX ctx;
 #endif
 	char auth_key[OSPF_AUTH_MD5_SIZE + 1];
 
+	assert(length <= UINT32_MAX); /* for coverity's sake */
+
 	memset(auth_key, 0, OSPF_AUTH_MD5_SIZE + 1);
 	strlcpy(auth_key, key->string, OSPF_AUTH_MD5_SIZE + 1);
-	ibuf = STREAM_DATA(op->s);
-	ospfh = (struct ospf_header *)ibuf;
-	length = ntohs(ospfh->length);
 	/* Generate a digest for the ospf packet - their digest + our digest. */
 #ifdef CRYPTO_OPENSSL
 	unsigned int md5_size = OSPF_AUTH_MD5_SIZE;