block-sha1/sha1.c

   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->size = 0;
  18
  19         /* Initialize H with the magic constants (see FIPS180 for constants)
  20          */
  21         ctx->H[0] = 0x67452301;
  22         ctx->H[1] = 0xefcdab89;
  23         ctx->H[2] = 0x98badcfe;
  24         ctx->H[3] = 0x10325476;
  25         ctx->H[4] = 0xc3d2e1f0;
  26 }
  27
  28
  29 void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *data, unsigned long len)
  30 {
  31         int lenW = ctx->size & 63;
  32
  33         ctx->size += len;
  34
  35         /* Read the data into W and process blocks as they get full
  36          */
  37         if (lenW) {
  38                 int left = 64 - lenW;
  39                 if (len < left)
  40                         left = len;
  41                 memcpy(lenW + (char *)ctx->W, data, left);
  42                 lenW = (lenW + left) & 63;
  43                 len -= left;
  44                 data += left;
  45                 if (lenW)
  46                         return;
  47                 blk_SHA1Block(ctx, ctx->W);
  48         }
  49         while (len >= 64) {
  50                 blk_SHA1Block(ctx, data);
  51                 data += 64;
  52                 len -= 64;
  53         }
  54         if (len)
  55                 memcpy(ctx->W, data, len);
  56 }
  57
  58
  59 void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx)
  60 {
  61         static const unsigned char pad[64] = { 0x80 };
  62         unsigned int padlen[2];
  63         int i;
  64
  65         /* Pad with a binary 1 (ie 0x80), then zeroes, then length
  66          */
  67         padlen[0] = htonl(ctx->size >> 29);
  68         padlen[1] = htonl(ctx->size << 3);
  69
  70         i = ctx->size & 63;
  71         blk_SHA1_Update(ctx, pad, 1+ (63 & (55 - i)));
  72         blk_SHA1_Update(ctx, padlen, 8);
  73
  74         /* Output hash
  75          */
  76         for (i = 0; i < 5; i++)
  77                 ((unsigned int *)hashout)[i] = htonl(ctx->H[i]);
  78 }
  79
  80 #if defined(__i386__) || defined(__x86_64__)
  81
  82 #define SHA_ASM(op, x, n) ({ unsigned int __res; __asm__(op " %1,%0":"=r" (__res):"i" (n), "0" (x)); __res; })
  83 #define SHA_ROL(x,n)    SHA_ASM("rol", x, n)
  84 #define SHA_ROR(x,n)    SHA_ASM("ror", x, n)
  85
  86 #else
  87
  88 #define SHA_ROT(X,l,r)  (((X) << (l)) | ((X) >> (r)))
  89 #define SHA_ROL(X,n)    SHA_ROT(X,n,32-(n))
  90 #define SHA_ROR(X,n)    SHA_ROT(X,32-(n),n)
  91
  92 #endif
  93
  94 /* This "rolls" over the 512-bit array */
  95 #define W(x) (array[(x)&15])
  96
  97 /*
  98  * Where do we get the source from? The first 16 iterations get it from
  99  * the input data, the next mix it from the 512-bit array.
 100  */
 101 #define SHA_SRC(t) htonl(data[t])
 102 #define SHA_MIX(t) SHA_ROL(W(t+13) ^ W(t+8) ^ W(t+2) ^ W(t), 1)
 103
 104 #define SHA_ROUND(t, input, fn, constant) \
 105         TEMP = input(t); W(t) = TEMP; \
 106         TEMP += SHA_ROL(A,5) + (fn) + E + (constant); \
 107         E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP
 108
 109 #define T_0_15(t)  SHA_ROUND(t, SHA_SRC, (((C^D)&B)^D) , 0x5a827999 )
 110 #define T_16_19(t) SHA_ROUND(t, SHA_MIX, (((C^D)&B)^D) , 0x5a827999 )
 111 #define T_20_39(t) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0x6ed9eba1 )
 112 #define T_40_59(t) SHA_ROUND(t, SHA_MIX, ((B&C)+(D&(B^C))) , 0x8f1bbcdc )
 113 #define T_60_79(t) SHA_ROUND(t, SHA_MIX, (B^C^D) ,  0xca62c1d6 )
 114
 115 static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data)
 116 {
 117         unsigned int A,B,C,D,E,TEMP;
 118         unsigned int array[16];
 119
 120         A = ctx->H[0];
 121         B = ctx->H[1];
 122         C = ctx->H[2];
 123         D = ctx->H[3];
 124         E = ctx->H[4];
 125
 126         /* Round 1 - iterations 0-16 take their input from 'data' */
 127         T_0_15( 0); T_0_15( 1); T_0_15( 2); T_0_15( 3); T_0_15( 4);
 128         T_0_15( 5); T_0_15( 6); T_0_15( 7); T_0_15( 8); T_0_15( 9);
 129         T_0_15(10); T_0_15(11); T_0_15(12); T_0_15(13); T_0_15(14);
 130         T_0_15(15);
 131
 132         /* Round 1 - tail. Input from 512-bit mixing array */
 133         T_16_19(16); T_16_19(17); T_16_19(18); T_16_19(19);
 134
 135         /* Round 2 */
 136         T_20_39(20); T_20_39(21); T_20_39(22); T_20_39(23); T_20_39(24);
 137         T_20_39(25); T_20_39(26); T_20_39(27); T_20_39(28); T_20_39(29);
 138         T_20_39(30); T_20_39(31); T_20_39(32); T_20_39(33); T_20_39(34);
 139         T_20_39(35); T_20_39(36); T_20_39(37); T_20_39(38); T_20_39(39);
 140
 141         /* Round 3 */
 142         T_40_59(40); T_40_59(41); T_40_59(42); T_40_59(43); T_40_59(44);
 143         T_40_59(45); T_40_59(46); T_40_59(47); T_40_59(48); T_40_59(49);
 144         T_40_59(50); T_40_59(51); T_40_59(52); T_40_59(53); T_40_59(54);
 145         T_40_59(55); T_40_59(56); T_40_59(57); T_40_59(58); T_40_59(59);
 146
 147         /* Round 4 */
 148         T_60_79(60); T_60_79(61); T_60_79(62); T_60_79(63); T_60_79(64);
 149         T_60_79(65); T_60_79(66); T_60_79(67); T_60_79(68); T_60_79(69);
 150         T_60_79(70); T_60_79(71); T_60_79(72); T_60_79(73); T_60_79(74);
 151         T_60_79(75); T_60_79(76); T_60_79(77); T_60_79(78); T_60_79(79);
 152
 153         ctx->H[0] += A;
 154         ctx->H[1] += B;
 155         ctx->H[2] += C;
 156         ctx->H[3] += D;
 157         ctx->H[4] += E;
 158 }