1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef LIBZIPARCHIVE_ENTRY_NAME_UTILS_INL_H_
18#define LIBZIPARCHIVE_ENTRY_NAME_UTILS_INL_H_
19
20#include <stddef.h>
21#include <stdint.h>
22
23// Check if |length| bytes at |entry_name| constitute a valid entry name.
24// Entry names must be valid UTF-8 and must not contain '0'.
25inline bool IsValidEntryName(const uint8_t* entry_name, const size_t length) {
26  for (size_t i = 0; i < length; ++i) {
27    const uint8_t byte = entry_name[i];
28    if (byte == 0) {
29      return false;
30    } else if ((byte & 0x80) == 0) {
31      // Single byte sequence.
32      continue;
33    } else if ((byte & 0xc0) == 0x80 || (byte & 0xfe) == 0xfe) {
34      // Invalid sequence.
35      return false;
36    } else {
37      // 2-5 byte sequences.
38      for (uint8_t first = byte << 1; first & 0x80; first <<= 1) {
39        ++i;
40
41        // Missing continuation byte..
42        if (i == length) {
43          return false;
44        }
45
46        // Invalid continuation byte.
47        const uint8_t continuation_byte = entry_name[i];
48        if ((continuation_byte & 0xc0) != 0x80) {
49          return false;
50        }
51      }
52    }
53  }
54
55  return true;
56}
57
58
59#endif  // LIBZIPARCHIVE_ENTRY_NAME_UTILS_INL_H_
60