The Tor Browser: gfx/skia/trunk/src/utils/SkMD5.cpp@129ffea94266 (annotated)

gfx/skia/trunk/src/utils/SkMD5.cpp@129ffea94266 (annotated)

gfx/skia/trunk/src/utils/SkMD5.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /*
  * 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
  */
 #include "SkTypes.h"
 #include "SkMD5.h"
 #include <string.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;
 }
 void SkMD5::update(const uint8_t* input, size_t inputLength) {
     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;
 }
 void SkMD5::finish(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 uint8_t PADDING[64] = {
 x80, 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,
     };
     this->update(PADDING, paddingLength);
     // Append length (length before padding, will cause final update).
     this->update(bits, 8);
     // Write out digest.
     encode(digest.data, this->state);
 #if defined(SK_MD5_CLEAR_DATA)
     // Clear state.
     memset(this, 0, sizeof(*this));
 #endif
 }
 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
 }

The Tor Browser / annotate

gfx/skia/trunk/src/utils/SkMD5.cpp@129ffea94266 (annotated)

gfx/skia/trunk/src/utils/SkMD5.cpp