sha1.cpp

免费压缩软件7zip的源码

// sha1.cpp
// This file from UnRar sources

#include "StdAfx.h"

#include "sha1.h"

/*
SHA-1 in C
By Steve Reid <[e-mail]>
100% Public Domain

 Test Vectors (from FIPS PUB 180-1)
 "abc"
 A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D
 "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
 84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1
 A million repetitions of "a"
 34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
*/

#if !defined(LITTLE_ENDIAN) && !defined(BIG_ENDIAN)
#if defined(_M_IX86) || defined(_M_I86) || defined(__alpha)
#define LITTLE_ENDIAN
#else
#error "LITTLE_ENDIAN or BIG_ENDIAN must be defined"
#endif
#endif

/* #define SHA1HANDSOFF * Copies data before messing with it. */

#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))

/* blk0() and blk() perform the initial expand. */
/* I got the idea of expanding during the round function from SSLeay */
#ifdef LITTLE_ENDIAN
#define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \
|(rol(block->l[i],8)&0x00FF00FF))
#else
#define blk0(i) block->l[i]
#endif
#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \
^block->l[(i+2)&15]^block->l[i&15],1))

/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
#define R0(v,w,x,y,z,i) {z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);}
#define R1(v,w,x,y,z,i) {z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);}
#define R2(v,w,x,y,z,i) {z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);}
#define R3(v,w,x,y,z,i) {z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);}
#define R4(v,w,x,y,z,i) {z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);}


/* Hash a single 512-bit block. This is the core of the algorithm. */

void SHA1Transform(UInt32 state[5], unsigned char buffer[64])
{
  UInt32 a, b, c, d, e;
  typedef union {
    unsigned char c[64];
    UInt32 l[16];
  } CHAR64LONG16;
  CHAR64LONG16* block;
#ifdef SHA1HANDSOFF
  static unsigned char workspace[64];
  block = (CHAR64LONG16*)workspace;
  memcpy(block, buffer, 64);
#else
  block = (CHAR64LONG16*)buffer;
#endif
#ifdef SFX_MODULE
  static int pos[80][5];
  static bool pinit=false;
  if (!pinit)
  {
    for (int I=0,P=0;I<80;I++,P=(P ? P-1:4))
    {
      pos[I][0]=P;
      pos[I][1]=(P+1)%5;
      pos[I][2]=(P+2)%5;
      pos[I][3]=(P+3)%5;
      pos[I][4]=(P+4)%5;
    }
    pinit=true;
  }
  UInt32 s[5];
  for (int I=0;I<sizeof(s)/sizeof(s[0]);I++)
    s[I]=state[I];
  
  for (int I=0;I<16;I++)
    R0(s[pos[I][0]],s[pos[I][1]],s[pos[I][2]],s[pos[I][3]],s[pos[I][4]],I);
  for (int I=16;I<20;I++)
    R1(s[pos[I][0]],s[pos[I][1]],s[pos[I][2]],s[pos[I][3]],s[pos[I][4]],I);
  for (int I=20;I<40;I++)
    R2(s[pos[I][0]],s[pos[I][1]],s[pos[I][2]],s[pos[I][3]],s[pos[I][4]],I);
  for (int I=40;I<60;I++)
    R3(s[pos[I][0]],s[pos[I][1]],s[pos[I][2]],s[pos[I][3]],s[pos[I][4]],I);
  for (int I=60;I<80;I++)
    R4(s[pos[I][0]],s[pos[I][1]],s[pos[I][2]],s[pos[I][3]],s[pos[I][4]],I);
  
  for (int I=0;I<sizeof(s)/sizeof(s[0]);I++)
    state[I]+=s[I];
#else
  /* Copy context->state[] to working vars */
  a = state[0];
  b = state[1];
  c = state[2];
  d = state[3];
  e = state[4];
  /* 4 rounds of 20 operations each. Loop unrolled. */
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  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);
  /* Add the working vars back into context.state[] */
  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;
  state[4] += e;
  
  /* Wipe variables */
  a = b = c = d = e = 0;
  memset(&a,0,sizeof(a));
#endif
}


/* Initialize new context */

void hash_initial(hash_context* context)
{
  /* SHA1 initialization constants */
  context->state[0] = 0x67452301;
  context->state[1] = 0xEFCDAB89;
  context->state[2] = 0x98BADCFE;
  context->state[3] = 0x10325476;
  context->state[4] = 0xC3D2E1F0;
  context->count[0] = context->count[1] = 0;
}


/* Run your data through this. */
void hash_process( hash_context * context, unsigned char * data, unsigned len )
{
  unsigned int i, j;
  UInt32 blen = ((UInt32)len)<<3;
  
  j = (context->count[0] >> 3) & 63;
  if ((context->count[0] += blen) < blen ) context->count[1]++;
  context->count[1] += (len >> 29);
  if ((j + len) > 63) {
    memcpy(&context->buffer[j], data, (i = 64-j));
    SHA1Transform(context->state, context->buffer);
    for ( ; i + 63 < len; i += 64) {
      SHA1Transform(context->state, &data[i]);
    }
    j = 0;
  }
  else i = 0;
  if (len > i)
    memcpy(&context->buffer[j], &data[i], len - i);
}


/* Add padding and return the message digest. */

void hash_final( hash_context* context, UInt32 digest[5] )
{
  UInt32 i, j;
  unsigned char finalcount[8];
  
  for (i = 0; i < 8; i++) {
    finalcount[i] = (unsigned char)((context->count[(i >= 4 ? 0 : 1)]
      >> ((3-(i & 3)) * 8) ) & 255);  /* Endian independent */
  }
  unsigned char ch='\200';
  hash_process(context, &ch, 1);
  while ((context->count[0] & 504) != 448) {
    ch=0;
    hash_process(context, &ch, 1);
  }
  hash_process(context, finalcount, 8);  /* Should cause a SHA1Transform() */
  for (i = 0; i < 5; i++) {
    digest[i] = context->state[i] & 0xffffffff;
  }
  /* Wipe variables */
  memset(&i,0,sizeof(i));
  memset(&j,0,sizeof(j));
  memset(context->buffer, 0, 64);
  memset(context->state, 0, 20);
  memset(context->count, 0, 8);
  memset(&finalcount, 0, 8);
#ifdef SHA1HANDSOFF  /* make SHA1Transform overwrite it's own static vars */
  SHA1Transform(context->state, context->buffer);
#endif
}