| /* |
| * Copyright 2012 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| * |
| * The following code is based on the description in RFC 1321. |
| * http://www.ietf.org/rfc/rfc1321.txt |
| */ |
| |
| //The following macros can be defined to affect the MD5 code generated. |
| //SK_MD5_CLEAR_DATA causes all intermediate state to be overwritten with 0's. |
| //SK_CPU_LENDIAN allows 32 bit <=> 8 bit conversions without copies (if alligned). |
| //SK_CPU_FAST_UNALIGNED_ACCESS allows 32 bit <=> 8 bit conversions without copies if SK_CPU_LENDIAN. |
| |
| #include "src/core/SkMD5.h" |
| |
| #include "include/private/base/SkFeatures.h" |
| |
| /** MD5 basic transformation. Transforms state based on block. */ |
| static void transform(uint32_t state[4], const uint8_t block[64]); |
| |
| /** Encodes input into output (4 little endian 32 bit values). */ |
| static void encode(uint8_t output[16], const uint32_t input[4]); |
| |
| /** Encodes input into output (little endian 64 bit value). */ |
| static void encode(uint8_t output[8], const uint64_t input); |
| |
| /** Decodes input (4 little endian 32 bit values) into storage, if required. */ |
| static const uint32_t* decode(uint32_t storage[16], const uint8_t input[64]); |
| |
| SkMD5::SkMD5() : byteCount(0) { |
| // These are magic numbers from the specification. |
| this->state[0] = 0x67452301; |
| this->state[1] = 0xefcdab89; |
| this->state[2] = 0x98badcfe; |
| this->state[3] = 0x10325476; |
| } |
| |
| bool SkMD5::write(const void* buf, size_t inputLength) { |
| const uint8_t* input = reinterpret_cast<const uint8_t*>(buf); |
| unsigned int bufferIndex = (unsigned int)(this->byteCount & 0x3F); |
| unsigned int bufferAvailable = 64 - bufferIndex; |
| |
| unsigned int inputIndex; |
| if (inputLength >= bufferAvailable) { |
| if (bufferIndex) { |
| memcpy(&this->buffer[bufferIndex], input, bufferAvailable); |
| transform(this->state, this->buffer); |
| inputIndex = bufferAvailable; |
| } else { |
| inputIndex = 0; |
| } |
| |
| for (; inputIndex + 63 < inputLength; inputIndex += 64) { |
| transform(this->state, &input[inputIndex]); |
| } |
| |
| bufferIndex = 0; |
| } else { |
| inputIndex = 0; |
| } |
| |
| memcpy(&this->buffer[bufferIndex], &input[inputIndex], inputLength - inputIndex); |
| |
| this->byteCount += inputLength; |
| return true; |
| } |
| |
| SkMD5::Digest SkMD5::finish() { |
| SkMD5::Digest digest; |
| // Get the number of bits before padding. |
| uint8_t bits[8]; |
| encode(bits, this->byteCount << 3); |
| |
| // Pad out to 56 mod 64. |
| unsigned int bufferIndex = (unsigned int)(this->byteCount & 0x3F); |
| unsigned int paddingLength = (bufferIndex < 56) ? (56 - bufferIndex) : (120 - bufferIndex); |
| static const uint8_t PADDING[64] = { |
| 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| }; |
| (void)this->write(PADDING, paddingLength); |
| |
| // Append length (length before padding, will cause final update). |
| (void)this->write(bits, 8); |
| |
| // Write out digest. |
| encode(digest.data, this->state); |
| |
| #if defined(SK_MD5_CLEAR_DATA) |
| // Clear state. |
| memset(this, 0, sizeof(*this)); |
| #endif |
| return digest; |
| } |
| |
| struct F { uint32_t operator()(uint32_t x, uint32_t y, uint32_t z) { |
| //return (x & y) | ((~x) & z); |
| return ((y ^ z) & x) ^ z; //equivelent but faster |
| }}; |
| |
| struct G { uint32_t operator()(uint32_t x, uint32_t y, uint32_t z) { |
| return (x & z) | (y & (~z)); |
| //return ((x ^ y) & z) ^ y; //equivelent but slower |
| }}; |
| |
| struct H { uint32_t operator()(uint32_t x, uint32_t y, uint32_t z) { |
| return x ^ y ^ z; |
| }}; |
| |
| struct I { uint32_t operator()(uint32_t x, uint32_t y, uint32_t z) { |
| return y ^ (x | (~z)); |
| }}; |
| |
| /** Rotates x left n bits. */ |
| static inline uint32_t rotate_left(uint32_t x, uint8_t n) { |
| return (x << n) | (x >> (32 - n)); |
| } |
| |
| template <typename T> |
| static inline void operation(T operation, uint32_t& a, uint32_t b, uint32_t c, uint32_t d, |
| uint32_t x, uint8_t s, uint32_t t) { |
| a = b + rotate_left(a + operation(b, c, d) + x + t, s); |
| } |
| |
| static void transform(uint32_t state[4], const uint8_t block[64]) { |
| uint32_t a = state[0], b = state[1], c = state[2], d = state[3]; |
| |
| uint32_t storage[16]; |
| const uint32_t* X = decode(storage, block); |
| |
| // Round 1 |
| operation(F(), a, b, c, d, X[ 0], 7, 0xd76aa478); // 1 |
| operation(F(), d, a, b, c, X[ 1], 12, 0xe8c7b756); // 2 |
| operation(F(), c, d, a, b, X[ 2], 17, 0x242070db); // 3 |
| operation(F(), b, c, d, a, X[ 3], 22, 0xc1bdceee); // 4 |
| operation(F(), a, b, c, d, X[ 4], 7, 0xf57c0faf); // 5 |
| operation(F(), d, a, b, c, X[ 5], 12, 0x4787c62a); // 6 |
| operation(F(), c, d, a, b, X[ 6], 17, 0xa8304613); // 7 |
| operation(F(), b, c, d, a, X[ 7], 22, 0xfd469501); // 8 |
| operation(F(), a, b, c, d, X[ 8], 7, 0x698098d8); // 9 |
| operation(F(), d, a, b, c, X[ 9], 12, 0x8b44f7af); // 10 |
| operation(F(), c, d, a, b, X[10], 17, 0xffff5bb1); // 11 |
| operation(F(), b, c, d, a, X[11], 22, 0x895cd7be); // 12 |
| operation(F(), a, b, c, d, X[12], 7, 0x6b901122); // 13 |
| operation(F(), d, a, b, c, X[13], 12, 0xfd987193); // 14 |
| operation(F(), c, d, a, b, X[14], 17, 0xa679438e); // 15 |
| operation(F(), b, c, d, a, X[15], 22, 0x49b40821); // 16 |
| |
| // Round 2 |
| operation(G(), a, b, c, d, X[ 1], 5, 0xf61e2562); // 17 |
| operation(G(), d, a, b, c, X[ 6], 9, 0xc040b340); // 18 |
| operation(G(), c, d, a, b, X[11], 14, 0x265e5a51); // 19 |
| operation(G(), b, c, d, a, X[ 0], 20, 0xe9b6c7aa); // 20 |
| operation(G(), a, b, c, d, X[ 5], 5, 0xd62f105d); // 21 |
| operation(G(), d, a, b, c, X[10], 9, 0x2441453); // 22 |
| operation(G(), c, d, a, b, X[15], 14, 0xd8a1e681); // 23 |
| operation(G(), b, c, d, a, X[ 4], 20, 0xe7d3fbc8); // 24 |
| operation(G(), a, b, c, d, X[ 9], 5, 0x21e1cde6); // 25 |
| operation(G(), d, a, b, c, X[14], 9, 0xc33707d6); // 26 |
| operation(G(), c, d, a, b, X[ 3], 14, 0xf4d50d87); // 27 |
| operation(G(), b, c, d, a, X[ 8], 20, 0x455a14ed); // 28 |
| operation(G(), a, b, c, d, X[13], 5, 0xa9e3e905); // 29 |
| operation(G(), d, a, b, c, X[ 2], 9, 0xfcefa3f8); // 30 |
| operation(G(), c, d, a, b, X[ 7], 14, 0x676f02d9); // 31 |
| operation(G(), b, c, d, a, X[12], 20, 0x8d2a4c8a); // 32 |
| |
| // Round 3 |
| operation(H(), a, b, c, d, X[ 5], 4, 0xfffa3942); // 33 |
| operation(H(), d, a, b, c, X[ 8], 11, 0x8771f681); // 34 |
| operation(H(), c, d, a, b, X[11], 16, 0x6d9d6122); // 35 |
| operation(H(), b, c, d, a, X[14], 23, 0xfde5380c); // 36 |
| operation(H(), a, b, c, d, X[ 1], 4, 0xa4beea44); // 37 |
| operation(H(), d, a, b, c, X[ 4], 11, 0x4bdecfa9); // 38 |
| operation(H(), c, d, a, b, X[ 7], 16, 0xf6bb4b60); // 39 |
| operation(H(), b, c, d, a, X[10], 23, 0xbebfbc70); // 40 |
| operation(H(), a, b, c, d, X[13], 4, 0x289b7ec6); // 41 |
| operation(H(), d, a, b, c, X[ 0], 11, 0xeaa127fa); // 42 |
| operation(H(), c, d, a, b, X[ 3], 16, 0xd4ef3085); // 43 |
| operation(H(), b, c, d, a, X[ 6], 23, 0x4881d05); // 44 |
| operation(H(), a, b, c, d, X[ 9], 4, 0xd9d4d039); // 45 |
| operation(H(), d, a, b, c, X[12], 11, 0xe6db99e5); // 46 |
| operation(H(), c, d, a, b, X[15], 16, 0x1fa27cf8); // 47 |
| operation(H(), b, c, d, a, X[ 2], 23, 0xc4ac5665); // 48 |
| |
| // Round 4 |
| operation(I(), a, b, c, d, X[ 0], 6, 0xf4292244); // 49 |
| operation(I(), d, a, b, c, X[ 7], 10, 0x432aff97); // 50 |
| operation(I(), c, d, a, b, X[14], 15, 0xab9423a7); // 51 |
| operation(I(), b, c, d, a, X[ 5], 21, 0xfc93a039); // 52 |
| operation(I(), a, b, c, d, X[12], 6, 0x655b59c3); // 53 |
| operation(I(), d, a, b, c, X[ 3], 10, 0x8f0ccc92); // 54 |
| operation(I(), c, d, a, b, X[10], 15, 0xffeff47d); // 55 |
| operation(I(), b, c, d, a, X[ 1], 21, 0x85845dd1); // 56 |
| operation(I(), a, b, c, d, X[ 8], 6, 0x6fa87e4f); // 57 |
| operation(I(), d, a, b, c, X[15], 10, 0xfe2ce6e0); // 58 |
| operation(I(), c, d, a, b, X[ 6], 15, 0xa3014314); // 59 |
| operation(I(), b, c, d, a, X[13], 21, 0x4e0811a1); // 60 |
| operation(I(), a, b, c, d, X[ 4], 6, 0xf7537e82); // 61 |
| operation(I(), d, a, b, c, X[11], 10, 0xbd3af235); // 62 |
| operation(I(), c, d, a, b, X[ 2], 15, 0x2ad7d2bb); // 63 |
| operation(I(), b, c, d, a, X[ 9], 21, 0xeb86d391); // 64 |
| |
| state[0] += a; |
| state[1] += b; |
| state[2] += c; |
| state[3] += d; |
| |
| #if defined(SK_MD5_CLEAR_DATA) |
| // Clear sensitive information. |
| if (X == &storage) { |
| memset(storage, 0, sizeof(storage)); |
| } |
| #endif |
| } |
| |
| static void encode(uint8_t output[16], const uint32_t input[4]) { |
| for (size_t i = 0, j = 0; i < 4; i++, j += 4) { |
| output[j ] = (uint8_t) (input[i] & 0xff); |
| output[j+1] = (uint8_t)((input[i] >> 8) & 0xff); |
| output[j+2] = (uint8_t)((input[i] >> 16) & 0xff); |
| output[j+3] = (uint8_t)((input[i] >> 24) & 0xff); |
| } |
| } |
| |
| static void encode(uint8_t output[8], const uint64_t input) { |
| output[0] = (uint8_t) (input & 0xff); |
| output[1] = (uint8_t)((input >> 8) & 0xff); |
| output[2] = (uint8_t)((input >> 16) & 0xff); |
| output[3] = (uint8_t)((input >> 24) & 0xff); |
| output[4] = (uint8_t)((input >> 32) & 0xff); |
| output[5] = (uint8_t)((input >> 40) & 0xff); |
| output[6] = (uint8_t)((input >> 48) & 0xff); |
| output[7] = (uint8_t)((input >> 56) & 0xff); |
| } |
| |
| static inline bool is_aligned(const void *pointer, size_t byte_count) { |
| return reinterpret_cast<uintptr_t>(pointer) % byte_count == 0; |
| } |
| |
| static const uint32_t* decode(uint32_t storage[16], const uint8_t input[64]) { |
| #if defined(SK_CPU_LENDIAN) && defined(SK_CPU_FAST_UNALIGNED_ACCESS) |
| return reinterpret_cast<const uint32_t*>(input); |
| #else |
| #if defined(SK_CPU_LENDIAN) |
| if (is_aligned(input, 4)) { |
| return reinterpret_cast<const uint32_t*>(input); |
| } |
| #endif |
| for (size_t i = 0, j = 0; j < 64; i++, j += 4) { |
| storage[i] = ((uint32_t)input[j ]) | |
| (((uint32_t)input[j+1]) << 8) | |
| (((uint32_t)input[j+2]) << 16) | |
| (((uint32_t)input[j+3]) << 24); |
| } |
| return storage; |
| #endif |
| } |