foundationdb/fdbclient/sha1/SHA1.cpp

251 lines
7.2 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();
}