From: Linus Torvalds Date: Wed, 5 Aug 2009 23:13:20 +0000 (-0700) Subject: Add new optimized C 'block-sha1' routines X-Git-Tag: v1.6.5-rc0~30^2~20 X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=d7c208a92e6b15cdcd159e30cd1fc0177fd967e9;p=git.git Add new optimized C 'block-sha1' routines Based on the mozilla SHA1 routine, but doing the input data accesses a word at a time and with 'htonl()' instead of loading bytes and shifting. It requires an architecture that is ok with unaligned 32-bit loads and a fast htonl(). Signed-off-by: Linus Torvalds Signed-off-by: Junio C Hamano --- diff --git a/Makefile b/Makefile index daf429670..e6df8ecde 100644 --- a/Makefile +++ b/Makefile @@ -84,6 +84,10 @@ all:: # specify your own (or DarwinPort's) include directories and # library directories by defining CFLAGS and LDFLAGS appropriately. # +# Define BLK_SHA1 environment variable if you want the C version +# of the SHA1 that assumes you can do unaligned 32-bit loads and +# have a fast htonl() function. +# # Define PPC_SHA1 environment variable when running make to make use of # a bundled SHA1 routine optimized for PowerPC. # @@ -1167,6 +1171,10 @@ ifdef NO_DEFLATE_BOUND BASIC_CFLAGS += -DNO_DEFLATE_BOUND endif +ifdef BLK_SHA1 + SHA1_HEADER = "block-sha1/sha1.h" + LIB_OBJS += block-sha1/sha1.o +else ifdef PPC_SHA1 SHA1_HEADER = "ppc/sha1.h" LIB_OBJS += ppc/sha1.o ppc/sha1ppc.o @@ -1184,6 +1192,7 @@ else endif endif endif +endif ifdef NO_PERL_MAKEMAKER export NO_PERL_MAKEMAKER endif diff --git a/block-sha1/sha1.c b/block-sha1/sha1.c new file mode 100644 index 000000000..50b2b42b0 --- /dev/null +++ b/block-sha1/sha1.c @@ -0,0 +1,145 @@ +/* + * Based on the Mozilla SHA1 (see mozilla-sha1/sha1.c), + * optimized to do word accesses rather than byte accesses, + * and to avoid unnecessary copies into the context array. + */ + +#include +#include + +#include "sha1.h" + +/* Hash one 64-byte block of data */ +static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data); + +void blk_SHA1_Init(blk_SHA_CTX *ctx) +{ + ctx->lenW = 0; + 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, unsigned long len) +{ + int lenW = ctx->lenW; + + ctx->size += len; + + /* Read the data into W and process blocks as they get full + */ + if (lenW) { + 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; + if (lenW) + return; + blk_SHA1Block(ctx, ctx->W); + } + while (len >= 64) { + blk_SHA1Block(ctx, data); + data += 64; + len -= 64; + } + 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 - 3)); + padlen[1] = htonl(ctx->size << 3); + + blk_SHA1_Update(ctx, pad, 1+ (63 & (55 - ctx->lenW))); + blk_SHA1_Update(ctx, padlen, 8); + + /* Output hash + */ + for (i = 0; i < 5; i++) + ((unsigned int *)hashout)[i] = htonl(ctx->H[i]); +} + +#define SHA_ROT(X,n) (((X) << (n)) | ((X) >> (32-(n)))) + +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_ROT(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_ROT(A,5) + (((C^D)&B)^D) + E + W[t] + 0x5a827999; \ + E = D; D = C; C = SHA_ROT(B, 30); 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_ROT(A,5) + (B^C^D) + E + W[t] + 0x6ed9eba1; \ + E = D; D = C; C = SHA_ROT(B, 30); 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_ROT(A,5) + ((B&C)|(D&(B|C))) + E + W[t] + 0x8f1bbcdc; \ + E = D; D = C; C = SHA_ROT(B, 30); 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_ROT(A,5) + (B^C^D) + E + W[t] + 0xca62c1d6; \ + E = D; D = C; C = SHA_ROT(B, 30); 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; +} diff --git a/block-sha1/sha1.h b/block-sha1/sha1.h new file mode 100644 index 000000000..7be2d93a2 --- /dev/null +++ b/block-sha1/sha1.h @@ -0,0 +1,21 @@ +/* + * Based on the Mozilla SHA1 (see mozilla-sha1/sha1.h), + * optimized to do word accesses rather than byte accesses, + * and to avoid unnecessary copies into the context array. + */ + +typedef struct { + unsigned int H[5]; + unsigned int W[16]; + int lenW; + unsigned long long size; +} blk_SHA_CTX; + +void blk_SHA1_Init(blk_SHA_CTX *ctx); +void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *dataIn, unsigned long len); +void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx); + +#define git_SHA_CTX blk_SHA_CTX +#define git_SHA1_Init blk_SHA1_Init +#define git_SHA1_Update blk_SHA1_Update +#define git_SHA1_Final blk_SHA1_Final