foundationdb/fdbclient/sha1/SHA1.cpp

265 lines
6.5 KiB
C++

/*
============
SHA-1 in C++
============
100% Public Domain.
Original C Code
-- Steve Reid <steve@edmweb.com>
Small changes to fit into bglibs
-- Bruce Guenter <bruce@untroubled.org>
Translation to simpler C++ Code
-- Volker Grabsch <vog@notjusthosting.com>
*/
#include "SHA1.h"
#include <sstream>
#include <iomanip>
#include <fstream>
/* Help macros */
#define SHA1_ROL(value, bits) (((value) << (bits)) | (((value) & 0xffffffff) >> (32 - (bits))))
#define SHA1_BLK(i) (block[i&15] = SHA1_ROL(block[(i+13)&15] ^ block[(i+8)&15] ^ block[(i+2)&15] ^ block[i&15],1))
/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
#define SHA1_R0(v,w,x,y,z,i) z += ((w&(x^y))^y) + block[i] + 0x5a827999 + SHA1_ROL(v,5); w=SHA1_ROL(w,30);
#define SHA1_R1(v,w,x,y,z,i) z += ((w&(x^y))^y) + SHA1_BLK(i) + 0x5a827999 + SHA1_ROL(v,5); w=SHA1_ROL(w,30);
#define SHA1_R2(v,w,x,y,z,i) z += (w^x^y) + SHA1_BLK(i) + 0x6ed9eba1 + SHA1_ROL(v,5); w=SHA1_ROL(w,30);
#define SHA1_R3(v,w,x,y,z,i) z += (((w|x)&y)|(w&x)) + SHA1_BLK(i) + 0x8f1bbcdc + SHA1_ROL(v,5); w=SHA1_ROL(w,30);
#define SHA1_R4(v,w,x,y,z,i) z += (w^x^y) + SHA1_BLK(i) + 0xca62c1d6 + SHA1_ROL(v,5); w=SHA1_ROL(w,30);
SHA1::SHA1()
{
reset();
}
void SHA1::update(const std::string &s)
{
std::istringstream is(s);
update(is);
}
void SHA1::update(std::istream &is)
{
std::string rest_of_buffer;
read(is, rest_of_buffer, BLOCK_BYTES - buffer.size());
buffer += rest_of_buffer;
while (is)
{
uint32 block[BLOCK_INTS];
buffer_to_block(buffer, block);
transform(block);
read(is, buffer, BLOCK_BYTES);
}
}
/*
* Add padding and return the message digest.
*/
std::string SHA1::final()
{
/* Total number of hashed bits */
uint64 total_bits = (transforms*BLOCK_BYTES + buffer.size()) * 8;
/* Padding */
buffer += 0x80;
std::string::size_type orig_size = (unsigned int)buffer.size();
while (buffer.size() < BLOCK_BYTES)
{
buffer += (char)0x00;
}
uint32 block[BLOCK_INTS];
buffer_to_block(buffer, block);
if (orig_size > BLOCK_BYTES - 8)
{
transform(block);
for (unsigned int i = 0; i < BLOCK_INTS - 2; i++)
{
block[i] = 0;
}
}
/* Append total_bits, split this uint64 into two uint32 */
block[BLOCK_INTS - 1] = (SHA1::uint32)total_bits;
block[BLOCK_INTS - 2] = (total_bits >> 32);
transform(block);
// Modified from original to output a binary string
std::string result;
result.reserve(16);
for (unsigned int i = 0; i < DIGEST_INTS; i++)
{
uint32 v = digest[i];
result.append(1, (char)(v >> 24));
result.append(1, (char)(v >> 16));
result.append(1, (char)(v >> 8));
result.append(1, (char)(v));
}
/* Reset for next run */
reset();
return result;
}
void SHA1::reset()
{
/* SHA1 initialization constants */
digest[0] = 0x67452301;
digest[1] = 0xefcdab89;
digest[2] = 0x98badcfe;
digest[3] = 0x10325476;
digest[4] = 0xc3d2e1f0;
/* Reset counters */
transforms = 0;
buffer = "";
}
/*
* Hash a single 512-bit block. This is the core of the algorithm.
*/
void SHA1::transform(uint32 block[BLOCK_BYTES])
{
/* Copy digest[] to working vars */
uint32 a = digest[0];
uint32 b = digest[1];
uint32 c = digest[2];
uint32 d = digest[3];
uint32 e = digest[4];
/* 4 rounds of 20 operations each. Loop unrolled. */
SHA1_R0(a,b,c,d,e, 0);
SHA1_R0(e,a,b,c,d, 1);
SHA1_R0(d,e,a,b,c, 2);
SHA1_R0(c,d,e,a,b, 3);
SHA1_R0(b,c,d,e,a, 4);
SHA1_R0(a,b,c,d,e, 5);
SHA1_R0(e,a,b,c,d, 6);
SHA1_R0(d,e,a,b,c, 7);
SHA1_R0(c,d,e,a,b, 8);
SHA1_R0(b,c,d,e,a, 9);
SHA1_R0(a,b,c,d,e,10);
SHA1_R0(e,a,b,c,d,11);
SHA1_R0(d,e,a,b,c,12);
SHA1_R0(c,d,e,a,b,13);
SHA1_R0(b,c,d,e,a,14);
SHA1_R0(a,b,c,d,e,15);
SHA1_R1(e,a,b,c,d,16);
SHA1_R1(d,e,a,b,c,17);
SHA1_R1(c,d,e,a,b,18);
SHA1_R1(b,c,d,e,a,19);
SHA1_R2(a,b,c,d,e,20);
SHA1_R2(e,a,b,c,d,21);
SHA1_R2(d,e,a,b,c,22);
SHA1_R2(c,d,e,a,b,23);
SHA1_R2(b,c,d,e,a,24);
SHA1_R2(a,b,c,d,e,25);
SHA1_R2(e,a,b,c,d,26);
SHA1_R2(d,e,a,b,c,27);
SHA1_R2(c,d,e,a,b,28);
SHA1_R2(b,c,d,e,a,29);
SHA1_R2(a,b,c,d,e,30);
SHA1_R2(e,a,b,c,d,31);
SHA1_R2(d,e,a,b,c,32);
SHA1_R2(c,d,e,a,b,33);
SHA1_R2(b,c,d,e,a,34);
SHA1_R2(a,b,c,d,e,35);
SHA1_R2(e,a,b,c,d,36);
SHA1_R2(d,e,a,b,c,37);
SHA1_R2(c,d,e,a,b,38);
SHA1_R2(b,c,d,e,a,39);
SHA1_R3(a,b,c,d,e,40);
SHA1_R3(e,a,b,c,d,41);
SHA1_R3(d,e,a,b,c,42);
SHA1_R3(c,d,e,a,b,43);
SHA1_R3(b,c,d,e,a,44);
SHA1_R3(a,b,c,d,e,45);
SHA1_R3(e,a,b,c,d,46);
SHA1_R3(d,e,a,b,c,47);
SHA1_R3(c,d,e,a,b,48);
SHA1_R3(b,c,d,e,a,49);
SHA1_R3(a,b,c,d,e,50);
SHA1_R3(e,a,b,c,d,51);
SHA1_R3(d,e,a,b,c,52);
SHA1_R3(c,d,e,a,b,53);
SHA1_R3(b,c,d,e,a,54);
SHA1_R3(a,b,c,d,e,55);
SHA1_R3(e,a,b,c,d,56);
SHA1_R3(d,e,a,b,c,57);
SHA1_R3(c,d,e,a,b,58);
SHA1_R3(b,c,d,e,a,59);
SHA1_R4(a,b,c,d,e,60);
SHA1_R4(e,a,b,c,d,61);
SHA1_R4(d,e,a,b,c,62);
SHA1_R4(c,d,e,a,b,63);
SHA1_R4(b,c,d,e,a,64);
SHA1_R4(a,b,c,d,e,65);
SHA1_R4(e,a,b,c,d,66);
SHA1_R4(d,e,a,b,c,67);
SHA1_R4(c,d,e,a,b,68);
SHA1_R4(b,c,d,e,a,69);
SHA1_R4(a,b,c,d,e,70);
SHA1_R4(e,a,b,c,d,71);
SHA1_R4(d,e,a,b,c,72);
SHA1_R4(c,d,e,a,b,73);
SHA1_R4(b,c,d,e,a,74);
SHA1_R4(a,b,c,d,e,75);
SHA1_R4(e,a,b,c,d,76);
SHA1_R4(d,e,a,b,c,77);
SHA1_R4(c,d,e,a,b,78);
SHA1_R4(b,c,d,e,a,79);
/* Add the working vars back into digest[] */
digest[0] += a;
digest[1] += b;
digest[2] += c;
digest[3] += d;
digest[4] += e;
/* Count the number of transformations */
transforms++;
}
void SHA1::buffer_to_block(const std::string &buffer, uint32 block[BLOCK_BYTES])
{
/* Convert the std::string (byte buffer) to a uint32 array (MSB) */
for (unsigned int i = 0; i < BLOCK_INTS; i++)
{
block[i] = (buffer[4*i+3] & 0xff)
| (buffer[4*i+2] & 0xff)<<8
| (buffer[4*i+1] & 0xff)<<16
| (buffer[4*i+0] & 0xff)<<24;
}
}
void SHA1::read(std::istream &is, std::string &s, int max)
{
char* sbuf = new char[max];
is.read(sbuf, max);
s.assign(sbuf, is.gcount());
delete [] sbuf;
}
std::string SHA1::from_string(const std::string &string)
{
SHA1 checksum;
checksum.update(string);
return checksum.final();
}