1/*
2 * Copyright 2013 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef SkSHA1_DEFINED
9#define SkSHA1_DEFINED
10
11#include "SkTypes.h"
12#include "SkEndian.h"
13#include "SkStream.h"
14
15//The following macros can be defined to affect the SHA1 code generated.
16//SK_SHA1_CLEAR_DATA causes all intermediate state to be overwritten with 0's.
17//SK_CPU_BENDIAN allows 32 bit <=> 8 bit conversions without copies (if alligned).
18//SK_CPU_FAST_UNALIGNED_ACCESS allows 32 bit <=> 8 bit conversions without copies if SK_CPU_BENDIAN.
19
20class SkSHA1 : public SkWStream {
21public:
22    SkSHA1();
23
24    /** Processes input, adding it to the digest.
25     *  Note that this treats the buffer as a series of uint8_t values.
26     */
27    virtual bool write(const void* buffer, size_t size) SK_OVERRIDE {
28        update(reinterpret_cast<const uint8_t*>(buffer), size);
29        return true;
30    }
31
32    virtual size_t bytesWritten() const SK_OVERRIDE { return SkToSizeT(this->byteCount); }
33
34    /** Processes input, adding it to the digest. Calling this after finish is undefined. */
35    void update(const uint8_t* input, size_t length);
36
37    struct Digest {
38        uint8_t data[20];
39    };
40
41    /** Computes and returns the digest. */
42    void finish(Digest& digest);
43
44private:
45    // number of bytes, modulo 2^64
46    uint64_t byteCount;
47
48    // state (ABCDE)
49    uint32_t state[5];
50
51    // input buffer
52    uint8_t buffer[64];
53};
54
55#endif
56