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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 <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Linus Torvalds committed Aug 5, 2009 at 16:13 UTC d7c208a92e6b15cdcd159e30cd1fc0177fd967e9
3 files changed +175
Makefile
+9
@@ -84,6 +84,10 @@ all::
84 # specify your own (or DarwinPort's) include directories and
85 # library directories by defining CFLAGS and LDFLAGS appropriately.
86 #
87 +# Define BLK_SHA1 environment variable if you want the C version
88 +# of the SHA1 that assumes you can do unaligned 32-bit loads and
89 +# have a fast htonl() function.
90 +#
91 # Define PPC_SHA1 environment variable when running make to make use of
92 # a bundled SHA1 routine optimized for PowerPC.
93 #
@@ -1167,6 +1171,10 @@ ifdef NO_DEFLATE_BOUND
1171 BASIC_CFLAGS += -DNO_DEFLATE_BOUND
1172 endif
1173
1174 +ifdef BLK_SHA1
1175 + SHA1_HEADER = "block-sha1/sha1.h"
1176 + LIB_OBJS += block-sha1/sha1.o
1177 +else
1178 ifdef PPC_SHA1
1179 SHA1_HEADER = "ppc/sha1.h"
1180 LIB_OBJS += ppc/sha1.o ppc/sha1ppc.o
@@ -1184,6 +1192,7 @@ else
1192 endif
1193 endif
1194 endif
1195 +endif
1196 ifdef NO_PERL_MAKEMAKER
1197 export NO_PERL_MAKEMAKER
1198 endif
block-sha1/sha1.c new
+145
@@ -0,0 +1,145 @@
1 +/*
2 + * Based on the Mozilla SHA1 (see mozilla-sha1/sha1.c),
3 + * optimized to do word accesses rather than byte accesses,
4 + * and to avoid unnecessary copies into the context array.
5 + */
6 +
7 +#include <string.h>
8 +#include <arpa/inet.h>
9 +
10 +#include "sha1.h"
11 +
12 +/* Hash one 64-byte block of data */
13 +static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data);
14 +
15 +void blk_SHA1_Init(blk_SHA_CTX *ctx)
16 +{
17 + ctx->lenW = 0;
18 + ctx->size = 0;
19 +
20 + /* Initialize H with the magic constants (see FIPS180 for constants)
21 + */
22 + ctx->H[0] = 0x67452301;
23 + ctx->H[1] = 0xefcdab89;
24 + ctx->H[2] = 0x98badcfe;
25 + ctx->H[3] = 0x10325476;
26 + ctx->H[4] = 0xc3d2e1f0;
27 +}
28 +
29 +
30 +void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *data, unsigned long len)
31 +{
32 + int lenW = ctx->lenW;
33 +
34 + ctx->size += len;
35 +
36 + /* Read the data into W and process blocks as they get full
37 + */
38 + if (lenW) {
39 + int left = 64 - lenW;
40 + if (len < left)
41 + left = len;
42 + memcpy(lenW + (char *)ctx->W, data, left);
43 + lenW = (lenW + left) & 63;
44 + len -= left;
45 + data += left;
46 + ctx->lenW = lenW;
47 + if (lenW)
48 + return;
49 + blk_SHA1Block(ctx, ctx->W);
50 + }
51 + while (len >= 64) {
52 + blk_SHA1Block(ctx, data);
53 + data += 64;
54 + len -= 64;
55 + }
56 + if (len) {
57 + memcpy(ctx->W, data, len);
58 + ctx->lenW = len;
59 + }
60 +}
61 +
62 +
63 +void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx)
64 +{
65 + static const unsigned char pad[64] = { 0x80 };
66 + unsigned int padlen[2];
67 + int i;
68 +
69 + /* Pad with a binary 1 (ie 0x80), then zeroes, then length
70 + */
71 + padlen[0] = htonl(ctx->size >> (32 - 3));
72 + padlen[1] = htonl(ctx->size << 3);
73 +
74 + blk_SHA1_Update(ctx, pad, 1+ (63 & (55 - ctx->lenW)));
75 + blk_SHA1_Update(ctx, padlen, 8);
76 +
77 + /* Output hash
78 + */
79 + for (i = 0; i < 5; i++)
80 + ((unsigned int *)hashout)[i] = htonl(ctx->H[i]);
81 +}
82 +
83 +#define SHA_ROT(X,n) (((X) << (n)) | ((X) >> (32-(n))))
84 +
85 +static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data)
86 +{
87 + int t;
88 + unsigned int A,B,C,D,E,TEMP;
89 + unsigned int W[80];
90 +
91 + for (t = 0; t < 16; t++)
92 + W[t] = htonl(data[t]);
93 +
94 + /* Unroll it? */
95 + for (t = 16; t <= 79; t++)
96 + W[t] = SHA_ROT(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16], 1);
97 +
98 + A = ctx->H[0];
99 + B = ctx->H[1];
100 + C = ctx->H[2];
101 + D = ctx->H[3];
102 + E = ctx->H[4];
103 +
104 +#define T_0_19(t) \
105 + TEMP = SHA_ROT(A,5) + (((C^D)&B)^D) + E + W[t] + 0x5a827999; \
106 + E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;
107 +
108 + T_0_19( 0); T_0_19( 1); T_0_19( 2); T_0_19( 3); T_0_19( 4);
109 + T_0_19( 5); T_0_19( 6); T_0_19( 7); T_0_19( 8); T_0_19( 9);
110 + T_0_19(10); T_0_19(11); T_0_19(12); T_0_19(13); T_0_19(14);
111 + T_0_19(15); T_0_19(16); T_0_19(17); T_0_19(18); T_0_19(19);
112 +
113 +#define T_20_39(t) \
114 + TEMP = SHA_ROT(A,5) + (B^C^D) + E + W[t] + 0x6ed9eba1; \
115 + E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;
116 +
117 + T_20_39(20); T_20_39(21); T_20_39(22); T_20_39(23); T_20_39(24);
118 + T_20_39(25); T_20_39(26); T_20_39(27); T_20_39(28); T_20_39(29);
119 + T_20_39(30); T_20_39(31); T_20_39(32); T_20_39(33); T_20_39(34);
120 + T_20_39(35); T_20_39(36); T_20_39(37); T_20_39(38); T_20_39(39);
121 +
122 +#define T_40_59(t) \
123 + TEMP = SHA_ROT(A,5) + ((B&C)|(D&(B|C))) + E + W[t] + 0x8f1bbcdc; \
124 + E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;
125 +
126 + T_40_59(40); T_40_59(41); T_40_59(42); T_40_59(43); T_40_59(44);
127 + T_40_59(45); T_40_59(46); T_40_59(47); T_40_59(48); T_40_59(49);
128 + T_40_59(50); T_40_59(51); T_40_59(52); T_40_59(53); T_40_59(54);
129 + T_40_59(55); T_40_59(56); T_40_59(57); T_40_59(58); T_40_59(59);
130 +
131 +#define T_60_79(t) \
132 + TEMP = SHA_ROT(A,5) + (B^C^D) + E + W[t] + 0xca62c1d6; \
133 + E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;
134 +
135 + T_60_79(60); T_60_79(61); T_60_79(62); T_60_79(63); T_60_79(64);
136 + T_60_79(65); T_60_79(66); T_60_79(67); T_60_79(68); T_60_79(69);
137 + T_60_79(70); T_60_79(71); T_60_79(72); T_60_79(73); T_60_79(74);
138 + T_60_79(75); T_60_79(76); T_60_79(77); T_60_79(78); T_60_79(79);
139 +
140 + ctx->H[0] += A;
141 + ctx->H[1] += B;
142 + ctx->H[2] += C;
143 + ctx->H[3] += D;
144 + ctx->H[4] += E;
145 +}
block-sha1/sha1.h new
+21
@@ -0,0 +1,21 @@
1 +/*
2 + * Based on the Mozilla SHA1 (see mozilla-sha1/sha1.h),
3 + * optimized to do word accesses rather than byte accesses,
4 + * and to avoid unnecessary copies into the context array.
5 + */
6 +
7 +typedef struct {
8 + unsigned int H[5];
9 + unsigned int W[16];
10 + int lenW;
11 + unsigned long long size;
12 +} blk_SHA_CTX;
13 +
14 +void blk_SHA1_Init(blk_SHA_CTX *ctx);
15 +void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *dataIn, unsigned long len);
16 +void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx);
17 +
18 +#define git_SHA_CTX blk_SHA_CTX
19 +#define git_SHA1_Init blk_SHA1_Init
20 +#define git_SHA1_Update blk_SHA1_Update
21 +#define git_SHA1_Final blk_SHA1_Final