From ab14c823dfbf1245712c8179952b51822135d8a8 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 6 Aug 2009 07:20:54 -0700 Subject: [PATCH] block-sha1: macroize the rounds a bit further Avoid repeating the shared parts of the different rounds by adding a macro layer or two. It was already more cpp than C. Signed-off-by: Linus Torvalds Signed-off-by: Junio C Hamano --- block-sha1/sha1.c | 56 ++++++++++++++++++++++------------------------- 1 file changed, 26 insertions(+), 30 deletions(-) diff --git a/block-sha1/sha1.c b/block-sha1/sha1.c index 8c4c216f93..53c93ba603 100644 --- a/block-sha1/sha1.c +++ b/block-sha1/sha1.c @@ -94,6 +94,27 @@ void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx) #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) htonl(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) \ + TEMP = input(t); W(t) = TEMP; \ + TEMP += SHA_ROL(A,5) + (fn) + E + (constant); \ + E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP + +#define T_0_15(t) SHA_ROUND(t, SHA_SRC, (((C^D)&B)^D) , 0x5a827999 ) +#define T_16_19(t) SHA_ROUND(t, SHA_MIX, (((C^D)&B)^D) , 0x5a827999 ) +#define T_20_39(t) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0x6ed9eba1 ) +#define T_40_59(t) SHA_ROUND(t, SHA_MIX, ((B&C)|(D&(B|C))) , 0x8f1bbcdc ) +#define T_60_79(t) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0xca62c1d6 ) + static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data) { unsigned int A,B,C,D,E,TEMP; @@ -105,53 +126,28 @@ static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data) D = ctx->H[3]; E = ctx->H[4]; -#define T_0_15(t) \ - TEMP = htonl(data[t]); array[t] = TEMP; \ - TEMP += SHA_ROL(A,5) + (((C^D)&B)^D) + E + 0x5a827999; \ - E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; \ - + /* Round 1 - iterations 0-16 take their input from 'data' */ T_0_15( 0); T_0_15( 1); T_0_15( 2); T_0_15( 3); T_0_15( 4); T_0_15( 5); T_0_15( 6); T_0_15( 7); T_0_15( 8); T_0_15( 9); T_0_15(10); T_0_15(11); T_0_15(12); T_0_15(13); T_0_15(14); T_0_15(15); -/* This "rolls" over the 512-bit array */ -#define W(x) (array[(x)&15]) -#define SHA_XOR(t) \ - TEMP = SHA_ROL(W(t+13) ^ W(t+8) ^ W(t+2) ^ W(t), 1); W(t) = TEMP; - -#define T_16_19(t) \ - SHA_XOR(t); \ - TEMP += SHA_ROL(A,5) + (((C^D)&B)^D) + E + 0x5a827999; \ - E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; \ - + /* Round 1 - tail. Input from 512-bit mixing array */ T_16_19(16); T_16_19(17); T_16_19(18); T_16_19(19); -#define T_20_39(t) \ - SHA_XOR(t); \ - TEMP += SHA_ROL(A,5) + (B^C^D) + E + 0x6ed9eba1; \ - E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; - + /* Round 2 */ 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) \ - SHA_XOR(t); \ - TEMP += SHA_ROL(A,5) + ((B&C)|(D&(B|C))) + E + 0x8f1bbcdc; \ - E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; - + /* Round 3 */ 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) \ - SHA_XOR(t); \ - TEMP += SHA_ROL(A,5) + (B^C^D) + E + 0xca62c1d6; \ - E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; - + /* Round 4 */ 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); -- 2.47.1