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      1 /*
      2  * ftp://ftp.funet.fi/pub/crypt/hash/sha/sha1.c
      3  *
      4  * SHA-1 in C
      5  * By Steve Reid <steve (at) edmweb.com>
      6  * 100% Public Domain
      7  *
      8  * Test Vectors (from FIPS PUB 180-1)
      9  * "abc"
     10  * A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D
     11  * "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
     12  * 84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1
     13  * A million repetitions of "a"
     14  * 34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
     15  */
     16 
     17 /* #define SHA1HANDSOFF * Copies data before messing with it. */
     18 
     19 #include <string.h>
     20 #include <netinet/in.h>	/* htonl() */
     21 #include "sha1.h"
     22 
     23 static void
     24 SHA1_Transform(u_int32_t[5], const unsigned char[64]);
     25 
     26 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
     27 
     28 /* blk0() and blk() perform the initial expand. */
     29 /* I got the idea of expanding during the round function from SSLeay */
     30 #define blk0(i) (block->l[i] = htonl(block->l[i]))
     31 #define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \
     32     ^block->l[(i+2)&15]^block->l[i&15],1))
     33 
     34 /* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
     35 #define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);
     36 #define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
     37 #define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
     38 #define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
     39 #define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);
     40 
     41 
     42 /* Hash a single 512-bit block. This is the core of the algorithm. */
     43 
     44 static void
     45 SHA1_Transform(u_int32_t state[5], const unsigned char buffer[64])
     46 {
     47     u_int32_t a, b, c, d, e;
     48     typedef union {
     49 	unsigned char c[64];
     50 	u_int32_t l[16];
     51     } CHAR64LONG16;
     52     CHAR64LONG16 *block;
     53 
     54 #ifdef SHA1HANDSOFF
     55     static unsigned char workspace[64];
     56     block = (CHAR64LONG16 *) workspace;
     57     memcpy(block, buffer, 64);
     58 #else
     59     block = (CHAR64LONG16 *) buffer;
     60 #endif
     61     /* Copy context->state[] to working vars */
     62     a = state[0];
     63     b = state[1];
     64     c = state[2];
     65     d = state[3];
     66     e = state[4];
     67     /* 4 rounds of 20 operations each. Loop unrolled. */
     68     R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
     69     R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
     70     R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
     71     R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
     72     R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
     73     R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
     74     R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
     75     R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
     76     R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
     77     R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
     78     R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
     79     R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
     80     R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
     81     R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
     82     R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
     83     R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
     84     R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
     85     R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
     86     R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
     87     R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
     88     /* Add the working vars back into context.state[] */
     89     state[0] += a;
     90     state[1] += b;
     91     state[2] += c;
     92     state[3] += d;
     93     state[4] += e;
     94     /* Wipe variables */
     95     a = b = c = d = e = 0;
     96 }
     97 
     98 
     99 /* SHA1Init - Initialize new context */
    100 
    101 void
    102 SHA1_Init(SHA1_CTX *context)
    103 {
    104     /* SHA1 initialization constants */
    105     context->state[0] = 0x67452301;
    106     context->state[1] = 0xEFCDAB89;
    107     context->state[2] = 0x98BADCFE;
    108     context->state[3] = 0x10325476;
    109     context->state[4] = 0xC3D2E1F0;
    110     context->count[0] = context->count[1] = 0;
    111 }
    112 
    113 
    114 /* Run your data through this. */
    115 
    116 void
    117 SHA1_Update(SHA1_CTX *context, const unsigned char *data, unsigned int len)
    118 {
    119     unsigned int i, j;
    120 
    121     j = (context->count[0] >> 3) & 63;
    122     if ((context->count[0] += len << 3) < (len << 3)) context->count[1]++;
    123     context->count[1] += (len >> 29);
    124     if ((j + len) > 63) {
    125 	memcpy(&context->buffer[j], data, (i = 64-j));
    126 	SHA1_Transform(context->state, context->buffer);
    127 	for ( ; i + 63 < len; i += 64) {
    128 	    SHA1_Transform(context->state, &data[i]);
    129 	}
    130 	j = 0;
    131     }
    132     else
    133 	i = 0;
    134 
    135     memcpy(&context->buffer[j], &data[i], len - i);
    136 }
    137 
    138 
    139 /* Add padding and return the message digest. */
    140 
    141 void
    142 SHA1_Final(unsigned char digest[20], SHA1_CTX *context)
    143 {
    144     u_int32_t i, j;
    145     unsigned char finalcount[8];
    146 
    147     for (i = 0; i < 8; i++) {
    148         finalcount[i] = (unsigned char)((context->count[(i >= 4 ? 0 : 1)]
    149          >> ((3-(i & 3)) * 8) ) & 255);  /* Endian independent */
    150     }
    151     SHA1_Update(context, (unsigned char *) "\200", 1);
    152     while ((context->count[0] & 504) != 448) {
    153 	SHA1_Update(context, (unsigned char *) "\0", 1);
    154     }
    155     SHA1_Update(context, finalcount, 8);  /* Should cause a SHA1Transform() */
    156     for (i = 0; i < 20; i++) {
    157 	digest[i] = (unsigned char)
    158 		     ((context->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
    159     }
    160     /* Wipe variables */
    161     i = j = 0;
    162     memset(context->buffer, 0, 64);
    163     memset(context->state, 0, 20);
    164     memset(context->count, 0, 8);
    165     memset(&finalcount, 0, 8);
    166 #ifdef SHA1HANDSOFF  /* make SHA1Transform overwrite it's own static vars */
    167     SHA1Transform(context->state, context->buffer);
    168 #endif
    169 }
    170 
    171