| /* |
| * SHA1 routine optimized to do word accesses rather than byte accesses, |
| * and to avoid unnecessary copies into the context array. |
| * |
| * This was initially based on the Mozilla SHA1 implementation, although |
| * none of the original Mozilla code remains. |
| */ |
| |
| /* this is only to get definitions for memcpy(), ntohl() and htonl() */ |
| #include "../git-compat-util.h" |
| |
| #include "sha1.h" |
| |
| #define SHA_ROT(X,l,r) (((X) << (l)) | ((X) >> (r))) |
| #define SHA_ROL(X,n) SHA_ROT(X,n,32-(n)) |
| #define SHA_ROR(X,n) SHA_ROT(X,32-(n),n) |
| |
| /* |
| * If you have 32 registers or more, the compiler can (and should) |
| * try to change the array[] accesses into registers. However, on |
| * machines with less than ~25 registers, that won't really work, |
| * and at least gcc will make an unholy mess of it. |
| * |
| * So to avoid that mess which just slows things down, we force |
| * the stores to memory to actually happen (we might be better off |
| * with a 'W(t)=(val);asm("":"+m" (W(t))' there instead, as |
| * suggested by Artur Skawina - that will also make gcc unable to |
| * try to do the silly "optimize away loads" part because it won't |
| * see what the value will be). |
| * |
| * On ARM we get the best code generation by forcing a full memory barrier |
| * between each SHA_ROUND, otherwise gcc happily get wild with spilling and |
| * the stack frame size simply explode and performance goes down the drain. |
| */ |
| |
| #if defined(__i386__) || defined(__x86_64__) |
| #define setW(x, val) (*(volatile unsigned int *)&W(x) = (val)) |
| #elif defined(__GNUC__) && defined(__arm__) |
| #define setW(x, val) do { W(x) = (val); __asm__("":::"memory"); } while (0) |
| #else |
| #define setW(x, val) (W(x) = (val)) |
| #endif |
| |
| /* This "rolls" over the 512-bit array */ |
| #define W(x) (array[(x)&15]) |
| |
| /* |
| * Where do we get the source from? The first 16 iterations get it from |
| * the input data, the next mix it from the 512-bit array. |
| */ |
| #define SHA_SRC(t) get_be32((unsigned char *) block + (t)*4) |
| #define SHA_MIX(t) SHA_ROL(W((t)+13) ^ W((t)+8) ^ W((t)+2) ^ W(t), 1) |
| |
| #define SHA_ROUND(t, input, fn, constant, A, B, C, D, E) do { \ |
| unsigned int TEMP = input(t); setW(t, TEMP); \ |
| E += TEMP + SHA_ROL(A,5) + (fn) + (constant); \ |
| B = SHA_ROR(B, 2); } while (0) |
| |
| #define T_0_15(t, A, B, C, D, E) SHA_ROUND(t, SHA_SRC, (((C^D)&B)^D) , 0x5a827999, A, B, C, D, E ) |
| #define T_16_19(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (((C^D)&B)^D) , 0x5a827999, A, B, C, D, E ) |
| #define T_20_39(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0x6ed9eba1, A, B, C, D, E ) |
| #define T_40_59(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, ((B&C)+(D&(B^C))) , 0x8f1bbcdc, A, B, C, D, E ) |
| #define T_60_79(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0xca62c1d6, A, B, C, D, E ) |
| |
| static void blk_SHA1_Block(blk_SHA_CTX *ctx, const void *block) |
| { |
| unsigned int A,B,C,D,E; |
| unsigned int array[16]; |
| |
| A = ctx->H[0]; |
| B = ctx->H[1]; |
| C = ctx->H[2]; |
| D = ctx->H[3]; |
| E = ctx->H[4]; |
| |
| /* Round 1 - iterations 0-16 take their input from 'block' */ |
| T_0_15( 0, A, B, C, D, E); |
| T_0_15( 1, E, A, B, C, D); |
| T_0_15( 2, D, E, A, B, C); |
| T_0_15( 3, C, D, E, A, B); |
| T_0_15( 4, B, C, D, E, A); |
| T_0_15( 5, A, B, C, D, E); |
| T_0_15( 6, E, A, B, C, D); |
| T_0_15( 7, D, E, A, B, C); |
| T_0_15( 8, C, D, E, A, B); |
| T_0_15( 9, B, C, D, E, A); |
| T_0_15(10, A, B, C, D, E); |
| T_0_15(11, E, A, B, C, D); |
| T_0_15(12, D, E, A, B, C); |
| T_0_15(13, C, D, E, A, B); |
| T_0_15(14, B, C, D, E, A); |
| T_0_15(15, A, B, C, D, E); |
| |
| /* Round 1 - tail. Input from 512-bit mixing array */ |
| T_16_19(16, E, A, B, C, D); |
| T_16_19(17, D, E, A, B, C); |
| T_16_19(18, C, D, E, A, B); |
| T_16_19(19, B, C, D, E, A); |
| |
| /* Round 2 */ |
| T_20_39(20, A, B, C, D, E); |
| T_20_39(21, E, A, B, C, D); |
| T_20_39(22, D, E, A, B, C); |
| T_20_39(23, C, D, E, A, B); |
| T_20_39(24, B, C, D, E, A); |
| T_20_39(25, A, B, C, D, E); |
| T_20_39(26, E, A, B, C, D); |
| T_20_39(27, D, E, A, B, C); |
| T_20_39(28, C, D, E, A, B); |
| T_20_39(29, B, C, D, E, A); |
| T_20_39(30, A, B, C, D, E); |
| T_20_39(31, E, A, B, C, D); |
| T_20_39(32, D, E, A, B, C); |
| T_20_39(33, C, D, E, A, B); |
| T_20_39(34, B, C, D, E, A); |
| T_20_39(35, A, B, C, D, E); |
| T_20_39(36, E, A, B, C, D); |
| T_20_39(37, D, E, A, B, C); |
| T_20_39(38, C, D, E, A, B); |
| T_20_39(39, B, C, D, E, A); |
| |
| /* Round 3 */ |
| T_40_59(40, A, B, C, D, E); |
| T_40_59(41, E, A, B, C, D); |
| T_40_59(42, D, E, A, B, C); |
| T_40_59(43, C, D, E, A, B); |
| T_40_59(44, B, C, D, E, A); |
| T_40_59(45, A, B, C, D, E); |
| T_40_59(46, E, A, B, C, D); |
| T_40_59(47, D, E, A, B, C); |
| T_40_59(48, C, D, E, A, B); |
| T_40_59(49, B, C, D, E, A); |
| T_40_59(50, A, B, C, D, E); |
| T_40_59(51, E, A, B, C, D); |
| T_40_59(52, D, E, A, B, C); |
| T_40_59(53, C, D, E, A, B); |
| T_40_59(54, B, C, D, E, A); |
| T_40_59(55, A, B, C, D, E); |
| T_40_59(56, E, A, B, C, D); |
| T_40_59(57, D, E, A, B, C); |
| T_40_59(58, C, D, E, A, B); |
| T_40_59(59, B, C, D, E, A); |
| |
| /* Round 4 */ |
| T_60_79(60, A, B, C, D, E); |
| T_60_79(61, E, A, B, C, D); |
| T_60_79(62, D, E, A, B, C); |
| T_60_79(63, C, D, E, A, B); |
| T_60_79(64, B, C, D, E, A); |
| T_60_79(65, A, B, C, D, E); |
| T_60_79(66, E, A, B, C, D); |
| T_60_79(67, D, E, A, B, C); |
| T_60_79(68, C, D, E, A, B); |
| T_60_79(69, B, C, D, E, A); |
| T_60_79(70, A, B, C, D, E); |
| T_60_79(71, E, A, B, C, D); |
| T_60_79(72, D, E, A, B, C); |
| T_60_79(73, C, D, E, A, B); |
| T_60_79(74, B, C, D, E, A); |
| T_60_79(75, A, B, C, D, E); |
| T_60_79(76, E, A, B, C, D); |
| T_60_79(77, D, E, A, B, C); |
| T_60_79(78, C, D, E, A, B); |
| T_60_79(79, B, C, D, E, A); |
| |
| ctx->H[0] += A; |
| ctx->H[1] += B; |
| ctx->H[2] += C; |
| ctx->H[3] += D; |
| ctx->H[4] += E; |
| } |
| |
| void blk_SHA1_Init(blk_SHA_CTX *ctx) |
| { |
| ctx->size = 0; |
| |
| /* Initialize H with the magic constants (see FIPS180 for constants) */ |
| ctx->H[0] = 0x67452301; |
| ctx->H[1] = 0xefcdab89; |
| ctx->H[2] = 0x98badcfe; |
| ctx->H[3] = 0x10325476; |
| ctx->H[4] = 0xc3d2e1f0; |
| } |
| |
| void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *data, size_t len) |
| { |
| unsigned int lenW = ctx->size & 63; |
| |
| ctx->size += len; |
| |
| /* Read the data into W and process blocks as they get full */ |
| if (lenW) { |
| unsigned int left = 64 - lenW; |
| if (len < left) |
| left = len; |
| memcpy(lenW + (char *)ctx->W, data, left); |
| lenW = (lenW + left) & 63; |
| len -= left; |
| data = ((const char *)data + left); |
| if (lenW) |
| return; |
| blk_SHA1_Block(ctx, ctx->W); |
| } |
| while (len >= 64) { |
| blk_SHA1_Block(ctx, data); |
| data = ((const char *)data + 64); |
| len -= 64; |
| } |
| if (len) |
| memcpy(ctx->W, data, len); |
| } |
| |
| void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx) |
| { |
| static const unsigned char pad[64] = { 0x80 }; |
| unsigned int padlen[2]; |
| int i; |
| |
| /* Pad with a binary 1 (ie 0x80), then zeroes, then length */ |
| padlen[0] = htonl((uint32_t)(ctx->size >> 29)); |
| padlen[1] = htonl((uint32_t)(ctx->size << 3)); |
| |
| i = ctx->size & 63; |
| blk_SHA1_Update(ctx, pad, 1 + (63 & (55 - i))); |
| blk_SHA1_Update(ctx, padlen, 8); |
| |
| /* Output hash */ |
| for (i = 0; i < 5; i++) |
| put_be32(hashout + i * 4, ctx->H[i]); |
| } |