release/src-rt-6.x.4708/tools/misc/xz/src/liblzma/check/sha256.c

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //
   3 /// \file       sha256.c
   4 /// \brief      SHA-256
   5 ///
   6 /// \todo       Crypto++ has x86 ASM optimizations. They use SSE so if they
   7 ///             are imported to liblzma, SSE instructions need to be used
   8 ///             conditionally to keep the code working on older boxes.
   9 ///             We could also support using some external libary for SHA-256.
  10 //
  11 //  This code is based on the code found from 7-Zip, which has a modified
  12 //  version of the SHA-256 found from Crypto++ <http://www.cryptopp.com/>.
  13 //  The code was modified a little to fit into liblzma.
  14 //
  15 //  Authors:    Kevin Springle
  16 //              Wei Dai
  17 //              Igor Pavlov
  18 //              Lasse Collin
  19 //
  20 //  This file has been put into the public domain.
  21 //  You can do whatever you want with this file.
  22 //
  23 ///////////////////////////////////////////////////////////////////////////////
  24
  25 // Avoid bogus warnings in transform().
  26 #if (__GNUC__ == 4 && __GNUC_MINOR__ >= 2) || __GNUC__ > 4
  27 #       pragma GCC diagnostic ignored "-Wuninitialized"
  28 #endif
  29
  30 #include "check.h"
  31
  32 // At least on x86, GCC is able to optimize this to a rotate instruction.
  33 #define rotr_32(num, amount) ((num) >> (amount) | (num) << (32 - (amount)))
  34
  35 #define blk0(i) (W[i] = data[i])
  36 #define blk2(i) (W[i & 15] += s1(W[(i - 2) & 15]) + W[(i - 7) & 15] \
  37                 + s0(W[(i - 15) & 15]))
  38
  39 #define Ch(x, y, z) (z ^ (x & (y ^ z)))
  40 #define Maj(x, y, z) ((x & y) | (z & (x | y)))
  41
  42 #define a(i) T[(0 - i) & 7]
  43 #define b(i) T[(1 - i) & 7]
  44 #define c(i) T[(2 - i) & 7]
  45 #define d(i) T[(3 - i) & 7]
  46 #define e(i) T[(4 - i) & 7]
  47 #define f(i) T[(5 - i) & 7]
  48 #define g(i) T[(6 - i) & 7]
  49 #define h(i) T[(7 - i) & 7]
  50
  51 #define R(i) \
  52         h(i) += S1(e(i)) + Ch(e(i), f(i), g(i)) + SHA256_K[i + j] \
  53                 + (j ? blk2(i) : blk0(i)); \
  54         d(i) += h(i); \
  55         h(i) += S0(a(i)) + Maj(a(i), b(i), c(i))
  56
  57 #define S0(x) (rotr_32(x, 2) ^ rotr_32(x, 13) ^ rotr_32(x, 22))
  58 #define S1(x) (rotr_32(x, 6) ^ rotr_32(x, 11) ^ rotr_32(x, 25))
  59 #define s0(x) (rotr_32(x, 7) ^ rotr_32(x, 18) ^ (x >> 3))
  60 #define s1(x) (rotr_32(x, 17) ^ rotr_32(x, 19) ^ (x >> 10))
  61
  62
  63 static const uint32_t SHA256_K[64] = {
  64         0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5,
  65         0x3956C25B, 0x59F111F1, 0x923F82A4, 0xAB1C5ED5,
  66         0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3,
  67         0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174,
  68         0xE49B69C1, 0xEFBE4786, 0x0FC19DC6, 0x240CA1CC,
  69         0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA,
  70         0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7,
  71         0xC6E00BF3, 0xD5A79147, 0x06CA6351, 0x14292967,
  72         0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13,
  73         0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85,
  74         0xA2BFE8A1, 0xA81A664B, 0xC24B8B70, 0xC76C51A3,
  75         0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070,
  76         0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5,
  77         0x391C0CB3, 0x4ED8AA4A, 0x5B9CCA4F, 0x682E6FF3,
  78         0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208,
  79         0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2,
  80 };
  81
  82
  83 static void
  84 transform(uint32_t state[static 8], const uint32_t data[static 16])
  85 {
  86         uint32_t W[16];
  87         uint32_t T[8];
  88
  89         // Copy state[] to working vars.
  90         memcpy(T, state, sizeof(T));
  91
  92         // 64 operations, partially loop unrolled
  93         for (unsigned int j = 0; j < 64; j += 16) {
  94                 R( 0); R( 1); R( 2); R( 3);
  95                 R( 4); R( 5); R( 6); R( 7);
  96                 R( 8); R( 9); R(10); R(11);
  97                 R(12); R(13); R(14); R(15);
  98         }
  99
 100         // Add the working vars back into state[].
 101         state[0] += a(0);
 102         state[1] += b(0);
 103         state[2] += c(0);
 104         state[3] += d(0);
 105         state[4] += e(0);
 106         state[5] += f(0);
 107         state[6] += g(0);
 108         state[7] += h(0);
 109 }
 110
 111
 112 static void
 113 process(lzma_check_state *check)
 114 {
 115 #ifdef WORDS_BIGENDIAN
 116         transform(check->state.sha256.state, check->buffer.u32);
 117
 118 #else
 119         uint32_t data[16];
 120
 121         for (size_t i = 0; i < 16; ++i)
 122                 data[i] = bswap32(check->buffer.u32[i]);
 123
 124         transform(check->state.sha256.state, data);
 125 #endif
 126
 127         return;
 128 }
 129
 130
 131 extern void
 132 lzma_sha256_init(lzma_check_state *check)
 133 {
 134         static const uint32_t s[8] = {
 135                 0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A,
 136                 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19,
 137         };
 138
 139         memcpy(check->state.sha256.state, s, sizeof(s));
 140         check->state.sha256.size = 0;
 141
 142         return;
 143 }
 144
 145
 146 extern void
 147 lzma_sha256_update(const uint8_t *buf, size_t size, lzma_check_state *check)
 148 {
 149         // Copy the input data into a properly aligned temporary buffer.
 150         // This way we can be called with arbitrarily sized buffers
 151         // (no need to be multiple of 64 bytes), and the code works also
 152         // on architectures that don't allow unaligned memory access.
 153         while (size > 0) {
 154                 const size_t copy_start = check->state.sha256.size & 0x3F;
 155                 size_t copy_size = 64 - copy_start;
 156                 if (copy_size > size)
 157                         copy_size = size;
 158
 159                 memcpy(check->buffer.u8 + copy_start, buf, copy_size);
 160
 161                 buf += copy_size;
 162                 size -= copy_size;
 163                 check->state.sha256.size += copy_size;
 164
 165                 if ((check->state.sha256.size & 0x3F) == 0)
 166                         process(check);
 167         }
 168
 169         return;
 170 }
 171
 172
 173 extern void
 174 lzma_sha256_finish(lzma_check_state *check)
 175 {
 176         // Add padding as described in RFC 3174 (it describes SHA-1 but
 177         // the same padding style is used for SHA-256 too).
 178         size_t pos = check->state.sha256.size & 0x3F;
 179         check->buffer.u8[pos++] = 0x80;
 180
 181         while (pos != 64 - 8) {
 182                 if (pos == 64) {
 183                         process(check);
 184                         pos = 0;
 185                 }
 186
 187                 check->buffer.u8[pos++] = 0x00;
 188         }
 189
 190         // Convert the message size from bytes to bits.
 191         check->state.sha256.size *= 8;
 192
 193         check->buffer.u64[(64 - 8) / 8] = conv64be(check->state.sha256.size);
 194
 195         process(check);
 196
 197         for (size_t i = 0; i < 8; ++i)
 198                 check->buffer.u32[i] = conv32be(check->state.sha256.state[i]);
 199
 200         return;
 201 }