MONGOCRYPT-891 fix check in KMIP parser (#1142)

Author: kevinAlbs

kms-message/src/kms_kmip_reader_writer.c

@@ -451,6 +451,7 @@ kmip_reader_find (kmip_reader_t *reader,
       if (read_tag == search_tag && read_type == type) {
          *pos = reader->pos;
          *length = read_length;
+         CHECK_REMAINING_BUFFER_AND_RET (compute_padded_length(read_length));
          return true;
       }
 
@@ -477,6 +478,10 @@ kmip_reader_find_and_recurse (kmip_reader_t *reader, kmip_tag_type_t tag)
    }
 
    reader->pos = 0;
+
+   if (pos + compute_padded_length (length) > reader->len) {
+      return false;
+   }
    reader->ptr = reader->ptr + pos;
    reader->len = length;
    return true;

kms-message/test/test_kmip_reader_writer.c

@@ -443,6 +443,26 @@ kms_kmip_reader_find_and_recurse_test (void)
    free (data);
 }
 
+void kms_kmip_reader_find_and_recurse_invalid_test (void); // -Wmissing-prototypes: for testing only.
+void
+kms_kmip_reader_find_and_recurse_invalid_test (void)
+{
+   uint8_t *data;
+   size_t datalen;
+   kmip_reader_t *reader;
+
+   // Structure with overly large length:
+   data = hex_to_data (
+      "42 00 20 | 01 | 00 00 00 FF", // Struct with bad length
+      &datalen);
+
+   reader = kmip_reader_new (data, datalen);
+   // Expect error:
+   ASSERT (!kmip_reader_find_and_recurse (reader, KMIP_TAG_CompromiseDate));
+   kmip_reader_destroy (reader);
+   free (data);
+}
+
 void kms_kmip_reader_find_and_read_enum_test (void); // -Wmissing-prototypes: for testing only.
 void
 kms_kmip_reader_find_and_read_enum_test (void)

kms-message/test/test_kms_request.c

@@ -1216,6 +1216,7 @@ extern void kms_kmip_reader_test (void);
 extern void kms_kmip_reader_negative_int_test (void);
 extern void kms_kmip_reader_find_test (void);
 extern void kms_kmip_reader_find_and_recurse_test (void);
+extern void kms_kmip_reader_find_and_recurse_invalid_test (void);
 extern void kms_kmip_reader_find_and_read_enum_test (void);
 extern void kms_kmip_reader_find_and_read_bytes_test (void);
 extern void kms_kmip_request_register_secretdata_test (void);
@@ -1280,6 +1281,7 @@ main (int argc, char *argv[])
    RUN_TEST (kms_kmip_reader_negative_int_test);
    RUN_TEST (kms_kmip_reader_test);
    RUN_TEST (kms_kmip_reader_find_and_recurse_test);
+   RUN_TEST (kms_kmip_reader_find_and_recurse_invalid_test);
    RUN_TEST (kms_kmip_reader_find_and_read_enum_test);
    RUN_TEST (kms_kmip_reader_find_and_read_bytes_test);
    RUN_TEST (kms_kmip_request_register_secretdata_test);