diff options
Diffstat (limited to 'src/hash/sha1/generic.c')
| -rw-r--r-- | src/hash/sha1/generic.c | 300 |
1 files changed, 0 insertions, 300 deletions
diff --git a/src/hash/sha1/generic.c b/src/hash/sha1/generic.c deleted file mode 100644 index 607fe3a43..000000000 --- a/src/hash/sha1/generic.c +++ /dev/null @@ -1,300 +0,0 @@ -/* - * Copyright (C) the libgit2 contributors. All rights reserved. - * - * This file is part of libgit2, distributed under the GNU GPL v2 with - * a Linking Exception. For full terms see the included COPYING file. - */ - -#include "generic.h" - -#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) - -/* - * Force usage of rol or ror by selecting the one with the smaller constant. - * It _can_ generate slightly smaller code (a constant of 1 is special), but - * perhaps more importantly it's possibly faster on any uarch that does a - * rotate with a loop. - */ - -#define SHA_ASM(op, x, n) (__extension__ ({ unsigned int __res; __asm__(op " %1,%0":"=r" (__res):"i" (n), "0" (x)); __res; })) -#define SHA_ROL(x,n) SHA_ASM("rol", x, n) -#define SHA_ROR(x,n) SHA_ASM("ror", x, n) - -#else - -#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) - -#endif - -/* - * 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). - * - * Ben Herrenschmidt reports that on PPC, the C version comes close - * to the optimized asm with this (ie on PPC you don't want that - * 'volatile', since there are lots of registers). - * - * 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 - -/* - * Performance might be improved if the CPU architecture is OK with - * unaligned 32-bit loads and a fast ntohl() is available. - * Otherwise fall back to byte loads and shifts which is portable, - * and is faster on architectures with memory alignment issues. - */ - -#if defined(__i386__) || defined(__x86_64__) || \ - defined(_M_IX86) || defined(_M_X64) || \ - defined(__ppc__) || defined(__ppc64__) || \ - defined(__powerpc__) || defined(__powerpc64__) || \ - defined(__s390__) || defined(__s390x__) - -#define get_be32(p) ntohl(*(const unsigned int *)(p)) -#define put_be32(p, v) do { *(unsigned int *)(p) = htonl(v); } while (0) - -#else - -#define get_be32(p) ( \ - (*((const unsigned char *)(p) + 0) << 24) | \ - (*((const unsigned char *)(p) + 1) << 16) | \ - (*((const unsigned char *)(p) + 2) << 8) | \ - (*((const unsigned char *)(p) + 3) << 0) ) -#define put_be32(p, v) do { \ - unsigned int __v = (v); \ - *((unsigned char *)(p) + 0) = __v >> 24; \ - *((unsigned char *)(p) + 1) = __v >> 16; \ - *((unsigned char *)(p) + 2) = __v >> 8; \ - *((unsigned char *)(p) + 3) = __v >> 0; } while (0) - -#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(data + t) -#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 hash__block(git_hash_sha1_ctx *ctx, const unsigned int *data) -{ - 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 'data' */ - 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; -} - -int git_hash_sha1_global_init(void) -{ - return 0; -} - -int git_hash_sha1_ctx_init(git_hash_sha1_ctx *ctx) -{ - return git_hash_sha1_init(ctx); -} - -void git_hash_sha1_ctx_cleanup(git_hash_sha1_ctx *ctx) -{ - GIT_UNUSED(ctx); -} - -int git_hash_sha1_init(git_hash_sha1_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; - - return 0; -} - -int git_hash_sha1_update(git_hash_sha1_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 = (unsigned int)len; - memcpy(lenW + (char *)ctx->W, data, left); - lenW = (lenW + left) & 63; - len -= left; - data = ((const char *)data + left); - if (lenW) - return 0; - hash__block(ctx, ctx->W); - } - while (len >= 64) { - hash__block(ctx, data); - data = ((const char *)data + 64); - len -= 64; - } - if (len) - memcpy(ctx->W, data, len); - - return 0; -} - -int git_hash_sha1_final(git_oid *out, git_hash_sha1_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; - git_hash_sha1_update(ctx, pad, 1+ (63 & (55 - i))); - git_hash_sha1_update(ctx, padlen, 8); - - /* Output hash */ - for (i = 0; i < 5; i++) - put_be32(out->id + i*4, ctx->H[i]); - - return 0; -} |