1 /* 2 * Copyright 2012 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 SkMD5_DEFINED 9 #define SkMD5_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 MD5 code generated. 16 //SK_MD5_CLEAR_DATA causes all intermediate state to be overwritten with 0's. 17 //SK_CPU_LENDIAN 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_LENDIAN. 19 20 class SkMD5 : public SkWStream { 21 public: 22 SkMD5(); 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 bool write(const void* buffer, size_t size) override { 28 this->update(reinterpret_cast<const uint8_t*>(buffer), size); 29 return true; 30 } 31 32 size_t bytesWritten() const 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[16]; 39 bool operator ==(Digest const& other) const { 40 return 0 == memcmp(data, other.data, sizeof(data)); 41 } 42 bool operator !=(Digest const& other) const { 43 return 0 != memcmp(data, other.data, sizeof(data)); 44 } 45 }; 46 47 /** Computes and returns the digest. */ 48 void finish(Digest& digest); 49 50 private: 51 // number of bytes, modulo 2^64 52 uint64_t byteCount; 53 54 // state (ABCD) 55 uint32_t state[4]; 56 57 // input buffer 58 uint8_t buffer[64]; 59 }; 60 61 #endif 62
