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.
8 #include "base/base_export.h"
9 #include "base/strings/string_piece.h"
13 // MD5 stands for Message Digest algorithm 5.
14 // MD5 is a robust hash function, designed for cyptography, but often used
15 // for file checksums. The code is complex and slow, but has few
18 // http://en.wikipedia.org/wiki/MD5
20 // These functions perform MD5 operations. The simplest call is MD5Sum() to
21 // generate the MD5 sum of the given data.
23 // You can also compute the MD5 sum of data incrementally by making multiple
24 // calls to MD5Update():
25 // MD5Context ctx; // intermediate MD5 data: do not use
27 // MD5Update(&ctx, data1, length1);
28 // MD5Update(&ctx, data2, length2);
31 // MD5Digest digest; // the result of the computation
32 // MD5Final(&digest, &ctx);
34 // You can call MD5DigestToBase16() to generate a string of the digest.
36 // The output of an MD5 operation.
41 // Used for storing intermediate data during an MD5 computation. Callers
42 // should not access the data.
43 typedef char MD5Context
[88];
45 // Computes the MD5 sum of the given data buffer with the given length.
46 // The given 'digest' structure will be filled with the result data.
47 BASE_EXPORT
void MD5Sum(const void* data
, size_t length
, MD5Digest
* digest
);
49 // Initializes the given MD5 context structure for subsequent calls to
51 BASE_EXPORT
void MD5Init(MD5Context
* context
);
53 // For the given buffer of |data| as a StringPiece, updates the given MD5
54 // context with the sum of the data. You can call this any number of times
55 // during the computation, except that MD5Init() must have been called first.
56 BASE_EXPORT
void MD5Update(MD5Context
* context
, const StringPiece
& data
);
58 // Finalizes the MD5 operation and fills the buffer with the digest.
59 BASE_EXPORT
void MD5Final(MD5Digest
* digest
, MD5Context
* context
);
61 // MD5IntermediateFinal() generates a digest without finalizing the MD5
62 // operation. Can be used to generate digests for the input seen thus far,
63 // without affecting the digest generated for the entire input.
64 BASE_EXPORT
void MD5IntermediateFinal(MD5Digest
* digest
,
65 const MD5Context
* context
);
67 // Converts a digest into human-readable hexadecimal.
68 BASE_EXPORT
std::string
MD5DigestToBase16(const MD5Digest
& digest
);
70 // Returns the MD5 (in hexadecimal) of a string.
71 BASE_EXPORT
std::string
MD5String(const StringPiece
& str
);