sha1.cpp

BVB杀毒软件的引擎代码,可以学习这种杀毒软件的核心 帮助自己设计杀毒软件

#include "Sha1.h"
 
 #ifdef SHA1_UTILITY_FUNCTIONS
 #define SHA1_MAX_FILE_BUFFER 8000
 #endif
 
 // Rotate x bits to the left
 #ifndef ROL32
 #ifdef _MSC_VER
 #define ROL32(_val32, _nBits) _rotl(_val32, _nBits)
 #else
 #define ROL32(_val32, _nBits) (((_val32)<<(_nBits))|((_val32)>>(32-(_nBits))))
 #endif
 #endif
 
 #ifdef SHA1_LITTLE_ENDIAN
 #define SHABLK0(i) (m_block->l[i] = \
 (ROL32(m_block->l[i],24) & 0xFF00FF00) | (ROL32(m_block->l[i],8) & 0x00FF00FF))
 #else
 #define SHABLK0(i) (m_block->l[i])
 #endif
 
 #define SHABLK(i) (m_block->l[i&15] = ROL32(m_block->l[(i+13)&15] ^ m_block->l[(i+8)&15] \
 ^ m_block->l[(i+2)&15] ^ m_block->l[i&15],1))
 
 // SHA-1 rounds
 #define _R0(v,w,x,y,z,i) { z+=((w&(x^y))^y)+SHABLK0(i)+0x5A827999+ROL32(v,5); w=ROL32(w,30); }
 #define _R1(v,w,x,y,z,i) { z+=((w&(x^y))^y)+SHABLK(i)+0x5A827999+ROL32(v,5); w=ROL32(w,30); }
 #define _R2(v,w,x,y,z,i) { z+=(w^x^y)+SHABLK(i)+0x6ED9EBA1+ROL32(v,5); w=ROL32(w,30); }
 #define _R3(v,w,x,y,z,i) { z+=(((w|x)&y)|(w&x))+SHABLK(i)+0x8F1BBCDC+ROL32(v,5); w=ROL32(w,30); }
 #define _R4(v,w,x,y,z,i) { z+=(w^x^y)+SHABLK(i)+0xCA62C1D6+ROL32(v,5); w=ROL32(w,30); }
 
 CSHA1::CSHA1()
 {
 m_block = (SHA1_WORKSPACE_BLOCK *)m_workspace;
 
 Reset();
 }
 
 CSHA1::~CSHA1()
 {
 Reset();
 }
 
 void CSHA1::Reset()
 {
 // SHA1 initialization constants
 m_state[0] = 0x67452301;
 m_state[1] = 0xEFCDAB89;
 m_state[2] = 0x98BADCFE;
 m_state[3] = 0x10325476;
 m_state[4] = 0xC3D2E1F0;
 
 m_count[0] = 0;
 m_count[1] = 0;
 }
 
 void CSHA1::Transform(UINT_32 *state, UINT_8 *buffer)
 {
 // Copy state[] to working vars
 UINT_32 a = state[0], b = state[1], c = state[2], d = state[3], e = state[4];
 
 memcpy(m_block, buffer, 64);
 
 // 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 state
 state[0] += a;
 state[1] += b;
 state[2] += c;
 state[3] += d;
 state[4] += e;
 
 // Wipe variables
 #ifdef SHA1_WIPE_VARIABLES
 a = b = c = d = e = 0;
 #endif
 }
 
 // Use this function to hash in binary data and strings
 void CSHA1::Update(UINT_8 *data, UINT_32 len)
 {
 UINT_32 i, j;
 
 j = (m_count[0] >> 3) & 63;
 
 if((m_count[0] += len << 3) < (len << 3)) m_count[1]++;
 
 m_count[1] += (len >> 29);
 
 if((j + len) > 63)
 {
 i = 64 - j;
 memcpy(&m_buffer[j], data, i);
 Transform(m_state, m_buffer);
 
 for( ; i + 63 < len; i += 64) Transform(m_state, &data[i]);
 
 j = 0;
 }
 else i = 0;
 
 memcpy(&m_buffer[j], &data[i], len - i);
 }
 
 #ifdef SHA1_UTILITY_FUNCTIONS
 // Hash in file contents
 bool CSHA1::HashFile(const char *szFileName)
 {
 unsigned long ulFileSize, ulRest, ulBlocks;
 unsigned long i;
 UINT_8 uData[SHA1_MAX_FILE_BUFFER];
 FILE *fIn;
 
 if(szFileName == NULL) return false;
 
 fIn = fopen(szFileName, "rb");
 if(fIn == NULL) return false;
 
 fseek(fIn, 0, SEEK_END);
 ulFileSize = (unsigned long)ftell(fIn);
 fseek(fIn, 0, SEEK_SET);
 
 if(ulFileSize != 0)
 {
 ulBlocks = ulFileSize / SHA1_MAX_FILE_BUFFER;
 ulRest = ulFileSize % SHA1_MAX_FILE_BUFFER;
 }
 else
 {
 ulBlocks = 0;
 ulRest = 0;
 }
 
 for(i = 0; i < ulBlocks; i++)
 {
 fread(uData, 1, SHA1_MAX_FILE_BUFFER, fIn);
 Update((UINT_8 *)uData, SHA1_MAX_FILE_BUFFER);
 }
 
 if(ulRest != 0)
 {
 fread(uData, 1, ulRest, fIn);
 Update((UINT_8 *)uData, ulRest);
 }
 
 fclose(fIn); fIn = NULL;
 return true;
 }
 #endif
 
 void CSHA1::Final()
 {
 UINT_32 i;
 UINT_8 finalcount[8];
 
 for(i = 0; i < 8; i++)
 finalcount[i] = (UINT_8)((m_count[((i >= 4) ? 0 : 1)]
 >> ((3 - (i & 3)) * 8) ) & 255); // Endian independent
 
 Update((UINT_8 *)"\200", 1);
 
 while ((m_count[0] & 504) != 448)
 Update((UINT_8 *)"\0", 1);
 
 Update(finalcount, 8); // Cause a SHA1Transform()
 
 for(i = 0; i < 20; i++)
 {
 m_digest[i] = (UINT_8)((m_state[i >> 2] >> ((3 - (i & 3)) * 8) ) & 255);
 }
 
 // Wipe variables for security reasons
 #ifdef SHA1_WIPE_VARIABLES
 i = 0;
 memset(m_buffer, 0, 64);
 memset(m_state, 0, 20);
 memset(m_count, 0, 8);
 memset(finalcount, 0, 8);
 Transform(m_state, m_buffer);
 #endif
 }
 
 #ifdef SHA1_UTILITY_FUNCTIONS
 // Get the final hash as a pre-formatted string
 void CSHA1::ReportHash(std::string &report, unsigned char uReportType)
 {
 unsigned char i;
 std::ostringstream o;
 
 if(uReportType == REPORT_HEX)
 {
 for(i = 0; i < 20; i++)
 {
 o.width(2);
 o << std::hex << (int)m_digest[i];
 }
 report = o.str();
 
 }
 else if(uReportType == REPORT_DIGIT)
 {
 for(i = 0; i < 20; i++)
 {
 o << (int)m_digest[i];
 }
 report = o.str();
 }
 else report = "Unkown report type.";
 }
 #endif
 
 // Get the raw message digest
 void CSHA1::GetHash(UINT_8 *puDest)
 {
 memcpy(puDest, m_digest, 20);
 }