Drizzled Public API Documentation

sha1.c

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00001 
00006 /*
00007  * SHA-1 in C
00008  * 
00009  * Copyright (C) 2010 nobody (this is public domain)
00010  *
00011  * This file is based on public domain code.
00012  * Initial source code is in the public domain, 
00013  * so clarified by Steve Reid <steve@edmweb.com>
00014  *
00015  * Test Vectors (from FIPS PUB 180-1)
00016  * "abc"
00017  *   A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D
00018  * "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
00019  *   84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1
00020  * A million repetitions of "a"
00021  *   34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
00022  */
00023 
00024 #include "common.h"
00025 
00026 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
00027 
00028 /*
00029  * blk0() and blk() perform the initial expand.
00030  * I got the idea of expanding during the round function from SSLeay
00031  */
00032 #ifndef WORDS_BIGENDIAN
00033 # define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \
00034     |(rol(block->l[i],8)&0x00FF00FF))
00035 #else
00036 # define blk0(i) block->l[i]
00037 #endif
00038 #define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \
00039     ^block->l[(i+2)&15]^block->l[i&15],1))
00040 
00041 /*
00042  * (R0+R1), R2, R3, R4 are the different operations (rounds) used in SHA1
00043  */
00044 #define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);
00045 #define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
00046 #define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
00047 #define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
00048 #define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);
00049 
00050 /*
00051  * Hash a single 512-bit block. This is the core of the algorithm.
00052  */
00053 void
00054 SHA1Transform(uint32_t state[5], const uint8_t buffer[SHA1_BLOCK_LENGTH])
00055 {
00056   uint32_t a, b, c, d, e;
00057   typedef union {
00058     uint8_t c[64];
00059     uint32_t l[16];
00060   } CHAR64LONG16;
00061   CHAR64LONG16 realBlock;
00062   CHAR64LONG16 *block= &realBlock;
00063 
00064   (void)memcpy(block, buffer, SHA1_BLOCK_LENGTH);
00065 
00066   /* Copy context->state[] to working vars */
00067   a = state[0];
00068   b = state[1];
00069   c = state[2];
00070   d = state[3];
00071   e = state[4];
00072 
00073   /* 4 rounds of 20 operations each. Loop unrolled. */
00074   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);
00075   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);
00076   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);
00077   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);
00078   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);
00079   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);
00080   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);
00081   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);
00082   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);
00083   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);
00084   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);
00085   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);
00086   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);
00087   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);
00088   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);
00089   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);
00090   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);
00091   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);
00092   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);
00093   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);
00094 
00095   /* Add the working vars back into context.state[] */
00096   state[0] += a;
00097   state[1] += b;
00098   state[2] += c;
00099   state[3] += d;
00100   state[4] += e;
00101 
00102   /* Wipe variables */
00103   a = b = c = d = e = 0;
00104 }
00105 
00106 
00107 /*
00108  * SHA1Init - Initialize new context
00109  */
00110 void
00111 SHA1Init(SHA1_CTX *context)
00112 {
00113 
00114   /* SHA1 initialization constants */
00115   context->count = 0;
00116   context->state[0] = 0x67452301;
00117   context->state[1] = 0xEFCDAB89;
00118   context->state[2] = 0x98BADCFE;
00119   context->state[3] = 0x10325476;
00120   context->state[4] = 0xC3D2E1F0;
00121 }
00122 
00123 
00124 /*
00125  * Run your data through this.
00126  */
00127 void
00128 SHA1Update(SHA1_CTX *context, const uint8_t *data, size_t len)
00129 {
00130   size_t i, j;
00131 
00132   j = (size_t)((context->count >> 3) & 63);
00133   context->count += (len << 3);
00134   if ((j + len) > 63) {
00135     (void)memcpy(&context->buffer[j], data, (i = 64-j));
00136     SHA1Transform(context->state, context->buffer);
00137     for ( ; i + 63 < len; i += 64)
00138       SHA1Transform(context->state, (uint8_t *)&data[i]);
00139     j = 0;
00140   } else {
00141     i = 0;
00142   }
00143   (void)memcpy(&context->buffer[j], &data[i], len - i);
00144 }
00145 
00146 
00147 /*
00148  * Add padding and return the message digest.
00149  */
00150 void
00151 SHA1Pad(SHA1_CTX *context)
00152 {
00153   uint8_t finalcount[8];
00154   u_int i;
00155 
00156   for (i = 0; i < 8; i++) {
00157     finalcount[i] = (uint8_t)((context->count >>
00158         ((7 - (i & 7)) * 8)) & 255);  /* Endian independent */
00159   }
00160   SHA1Update(context, (uint8_t *)"\200", 1);
00161   while ((context->count & 504) != 448)
00162     SHA1Update(context, (uint8_t *)"\0", 1);
00163   SHA1Update(context, finalcount, 8); /* Should cause a SHA1Transform() */
00164 }
00165 
00166 void
00167 SHA1Final(uint8_t digest[SHA1_DIGEST_LENGTH], SHA1_CTX *context)
00168 {
00169   u_int i;
00170 
00171   SHA1Pad(context);
00172   if (digest) {
00173     for (i = 0; i < SHA1_DIGEST_LENGTH; i++) {
00174       digest[i] = (uint8_t)
00175          ((context->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
00176     }
00177     memset(context, 0, sizeof(*context));
00178   }
00179 }