Fix overflow checks in x509write_crt

Previous ones could still overflow.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
This commit is contained in:
Andrzej Kurek 2023-06-02 05:02:41 -04:00
parent 51cef9ce38
commit 7c86974d6d

View file

@ -186,19 +186,23 @@ int mbedtls_x509write_crt_set_subject_alternative_name(mbedtls_x509write_cert *c
* maximum 4 bytes for the length field,
* 1 byte for the tag/type.
*/
CHECK_OVERFLOW_ADD(buflen, cur->node.san.unstructured_name.len + 4 + 1);
CHECK_OVERFLOW_ADD(buflen, cur->node.san.unstructured_name.len);
CHECK_OVERFLOW_ADD(buflen, 4 + 1);
break;
case MBEDTLS_X509_SAN_DIRECTORY_NAME:
{
const mbedtls_asn1_named_data *chunk = &cur->node.san.directory_name;
while (chunk != NULL) {
// 5 bytes for OID, max 4 bytes for length, +1 for tag,
// Max 4 bytes for length, +1 for tag,
// additional 4 max for length, +1 for tag.
// See x509_write_name for more information.
CHECK_OVERFLOW_ADD(buflen, chunk->val.len + 5 + 4 + 1 + 4 + 1);
CHECK_OVERFLOW_ADD(buflen, 4 + 1 + 4 + 1);
CHECK_OVERFLOW_ADD(buflen, chunk->oid.len);
CHECK_OVERFLOW_ADD(buflen, chunk->val.len);
chunk = chunk->next;
}
CHECK_OVERFLOW_ADD(buflen, cur->node.san.unstructured_name.len + 4 + 1);
CHECK_OVERFLOW_ADD(buflen, cur->node.san.unstructured_name.len);
CHECK_OVERFLOW_ADD(buflen, 4 + 1);
break;
}
default: