EAP-MSCHAPv2: Check hash function results more consistently (CID 68105)

While the hash functions would be very unlikely to fail in practice,
they do have option of returning an error. Check that return value more
consistently.

Signed-off-by: Jouni Malinen <j@w1.fi>

src/eap_peer/eap_mschapv2.c

@@ -309,10 +309,13 @@ static void eap_mschapv2_password_changed(struct eap_sm *sm,
 		} else if (config->flags & EAP_CONFIG_FLAGS_PASSWORD_NTHASH) {
 			config->password = os_malloc(16);
 			config->password_len = 16;
-			if (config->password) {
-				nt_password_hash(config->new_password,
-						 config->new_password_len,
-						 config->password);
+			if (config->password &&
+			    nt_password_hash(config->new_password,
+					     config->new_password_len,
+					     config->password)) {
+				os_free(config->password);
+				config->password = NULL;
+				config->password_len = 0;
 			}
 			os_free(config->new_password);
 		} else {
@@ -549,15 +552,17 @@ static struct wpabuf * eap_mschapv2_change_password(
 	/* Encrypted-Hash */
 	if (pwhash) {
 		u8 new_password_hash[16];
-		nt_password_hash(new_password, new_password_len,
-				 new_password_hash);
+		if (nt_password_hash(new_password, new_password_len,
+				     new_password_hash))
+			goto fail;
 		nt_password_hash_encrypted_with_block(password,
 						      new_password_hash,
 						      cp->encr_hash);
 	} else {
-		old_nt_password_hash_encrypted_with_new_nt_password_hash(
-			new_password, new_password_len,
-			password, password_len, cp->encr_hash);
+		if (old_nt_password_hash_encrypted_with_new_nt_password_hash(
+			    new_password, new_password_len,
+			    password, password_len, cp->encr_hash))
+			goto fail;
 	}
 
 	/* Peer-Challenge */
@@ -594,9 +599,13 @@ static struct wpabuf * eap_mschapv2_change_password(
 
 	/* Likewise, generate master_key here since we have the needed data
 	 * available. */
-	nt_password_hash(new_password, new_password_len, password_hash);
-	hash_nt_password_hash(password_hash, password_hash_hash);
-	get_master_key(password_hash_hash, cp->nt_response, data->master_key);
+	if (nt_password_hash(new_password, new_password_len, password_hash) ||
+	    hash_nt_password_hash(password_hash, password_hash_hash) ||
+	    get_master_key(password_hash_hash, cp->nt_response,
+			   data->master_key)) {
+		data->auth_response_valid = 0;
+		goto fail;
+	}
 	data->master_key_valid = 1;
 
 	/* Flags */