1// Copyright (c) 2011 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4//
5// The original source code is from:
6// http://src.chromium.org/viewvc/chrome/trunk/src/base/md5.h?revision=94203
7
8#ifndef I18N_ADDRESSINPUT_UTIL_MD5_H_
9#define I18N_ADDRESSINPUT_UTIL_MD5_H_
10
11#include <cstddef>
12#include <string>
13
14namespace i18n {
15namespace addressinput {
16
17// MD5 stands for Message Digest algorithm 5.
18// MD5 is a robust hash function, designed for cyptography, but often used
19// for file checksums.  The code is complex and slow, but has few
20// collisions.
21// See Also:
22//   http://en.wikipedia.org/wiki/MD5
23
24// These functions perform MD5 operations. The simplest call is MD5Sum() to
25// generate the MD5 sum of the given data.
26//
27// You can also compute the MD5 sum of data incrementally by making multiple
28// calls to MD5Update():
29//   MD5Context ctx; // intermediate MD5 data: do not use
30//   MD5Init(&ctx);
31//   MD5Update(&ctx, data1, length1);
32//   MD5Update(&ctx, data2, length2);
33//   ...
34//
35//   MD5Digest digest; // the result of the computation
36//   MD5Final(&digest, &ctx);
37//
38// You can call MD5DigestToBase16() to generate a string of the digest.
39
40// The output of an MD5 operation.
41struct MD5Digest {
42  unsigned char a[16];
43};
44
45// Used for storing intermediate data during an MD5 computation. Callers
46// should not access the data.
47typedef char MD5Context[88];
48
49// Computes the MD5 sum of the given data buffer with the given length.
50// The given 'digest' structure will be filled with the result data.
51void MD5Sum(const void* data, size_t length, MD5Digest* digest);
52
53// Initializes the given MD5 context structure for subsequent calls to
54// MD5Update().
55void MD5Init(MD5Context* context);
56
57// For the given buffer of |data| as a StringPiece, updates the given MD5
58// context with the sum of the data. You can call this any number of times
59// during the computation, except that MD5Init() must have been called first.
60void MD5Update(MD5Context* context, const std::string& data);
61
62// Finalizes the MD5 operation and fills the buffer with the digest.
63void MD5Final(MD5Digest* digest, MD5Context* context);
64
65// Converts a digest into human-readable hexadecimal.
66std::string MD5DigestToBase16(const MD5Digest& digest);
67
68// Returns the MD5 (in hexadecimal) of a string.
69std::string MD5String(const std::string& str);
70
71}  // namespace addressinput
72}  // namespace i18n
73
74#endif  // I18N_ADDRESSINPUT_UTIL_MD5_H_
75