X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=block-sha1%2Fsha1.c;h=d8934757a5e5e259f26c4a09f7ea5d10615df0c1;hb=5b5275f6e9ca6284ca123f729d5a78f409e448fb;hp=a45a3dec1e02e4168efc9656fea728cbb355d0fe;hpb=b8e48a89b8f581eaf95b57782bb8e620ca30e968;p=git.git diff --git a/block-sha1/sha1.c b/block-sha1/sha1.c index a45a3dec1..c0054a0b0 100644 --- a/block-sha1/sha1.c +++ b/block-sha1/sha1.c @@ -1,24 +1,233 @@ /* - * Based on the Mozilla SHA1 (see mozilla-sha1/sha1.c), - * optimized to do word accesses rather than byte accesses, + * 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. */ -#include -#include +/* this is only to get definitions for memcpy(), ntohl() and htonl() */ +#include "../git-compat-util.h" #include "sha1.h" -/* Hash one 64-byte block of data */ -static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data); +#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) ({ 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(*(unsigned int *)(p)) +#define put_be32(p, v) do { *(unsigned int *)(p) = htonl(v); } while (0) + +#else + +#define get_be32(p) ( \ + (*((unsigned char *)(p) + 0) << 24) | \ + (*((unsigned char *)(p) + 1) << 16) | \ + (*((unsigned char *)(p) + 2) << 8) | \ + (*((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 blk_SHA1_Block(blk_SHA_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; +} void blk_SHA1_Init(blk_SHA_CTX *ctx) { - ctx->lenW = 0; ctx->size = 0; - /* Initialize H with the magic constants (see FIPS180 for constants) - */ + /* Initialize H with the magic constants (see FIPS180 for constants) */ ctx->H[0] = 0x67452301; ctx->H[1] = 0xefcdab89; ctx->H[2] = 0x98badcfe; @@ -26,132 +235,49 @@ void blk_SHA1_Init(blk_SHA_CTX *ctx) ctx->H[4] = 0xc3d2e1f0; } - void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *data, unsigned long len) { - int lenW = ctx->lenW; + unsigned int lenW = ctx->size & 63; - ctx->size += (unsigned long long) len << 3; + ctx->size += len; - /* Read the data into W and process blocks as they get full - */ + /* Read the data into W and process blocks as they get full */ if (lenW) { - int left = 64 - 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 += left; - ctx->lenW = lenW; + data = ((const char *)data + left); if (lenW) return; - blk_SHA1Block(ctx, ctx->W); + blk_SHA1_Block(ctx, ctx->W); } while (len >= 64) { - blk_SHA1Block(ctx, data); - data += 64; + blk_SHA1_Block(ctx, data); + data = ((const char *)data + 64); len -= 64; } - if (len) { + if (len) memcpy(ctx->W, data, len); - ctx->lenW = 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(ctx->size >> 32); - padlen[1] = htonl(ctx->size); + /* 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)); - blk_SHA1_Update(ctx, pad, 1+ (63 & (55 - ctx->lenW))); + i = ctx->size & 63; + blk_SHA1_Update(ctx, pad, 1+ (63 & (55 - i))); blk_SHA1_Update(ctx, padlen, 8); - /* Output hash - */ + /* Output hash */ for (i = 0; i < 5; i++) - ((unsigned int *)hashout)[i] = htonl(ctx->H[i]); -} - -#if defined(__i386__) || defined(__x86_64__) - -#define SHA_ASM(op, x, n) ({ 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,n) (((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 - -static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data) -{ - int t; - unsigned int A,B,C,D,E,TEMP; - unsigned int W[80]; - - for (t = 0; t < 16; t++) - W[t] = htonl(data[t]); - - /* Unroll it? */ - for (t = 16; t <= 79; t++) - W[t] = SHA_ROL(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16], 1); - - A = ctx->H[0]; - B = ctx->H[1]; - C = ctx->H[2]; - D = ctx->H[3]; - E = ctx->H[4]; - -#define T_0_19(t) \ - TEMP = SHA_ROL(A,5) + (((C^D)&B)^D) + E + W[t] + 0x5a827999; \ - E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; - - T_0_19( 0); T_0_19( 1); T_0_19( 2); T_0_19( 3); T_0_19( 4); - T_0_19( 5); T_0_19( 6); T_0_19( 7); T_0_19( 8); T_0_19( 9); - T_0_19(10); T_0_19(11); T_0_19(12); T_0_19(13); T_0_19(14); - T_0_19(15); T_0_19(16); T_0_19(17); T_0_19(18); T_0_19(19); - -#define T_20_39(t) \ - TEMP = SHA_ROL(A,5) + (B^C^D) + E + W[t] + 0x6ed9eba1; \ - E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; - - T_20_39(20); T_20_39(21); T_20_39(22); T_20_39(23); T_20_39(24); - T_20_39(25); T_20_39(26); T_20_39(27); T_20_39(28); T_20_39(29); - T_20_39(30); T_20_39(31); T_20_39(32); T_20_39(33); T_20_39(34); - T_20_39(35); T_20_39(36); T_20_39(37); T_20_39(38); T_20_39(39); - -#define T_40_59(t) \ - TEMP = SHA_ROL(A,5) + ((B&C)|(D&(B|C))) + E + W[t] + 0x8f1bbcdc; \ - E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; - - T_40_59(40); T_40_59(41); T_40_59(42); T_40_59(43); T_40_59(44); - T_40_59(45); T_40_59(46); T_40_59(47); T_40_59(48); T_40_59(49); - T_40_59(50); T_40_59(51); T_40_59(52); T_40_59(53); T_40_59(54); - T_40_59(55); T_40_59(56); T_40_59(57); T_40_59(58); T_40_59(59); - -#define T_60_79(t) \ - TEMP = SHA_ROL(A,5) + (B^C^D) + E + W[t] + 0xca62c1d6; \ - E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; - - T_60_79(60); T_60_79(61); T_60_79(62); T_60_79(63); T_60_79(64); - T_60_79(65); T_60_79(66); T_60_79(67); T_60_79(68); T_60_79(69); - T_60_79(70); T_60_79(71); T_60_79(72); T_60_79(73); T_60_79(74); - T_60_79(75); T_60_79(76); T_60_79(77); T_60_79(78); T_60_79(79); - - ctx->H[0] += A; - ctx->H[1] += B; - ctx->H[2] += C; - ctx->H[3] += D; - ctx->H[4] += E; + put_be32(hashout + i*4, ctx->H[i]); }