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ktorrent/libktorrent/util/sha1hashgen.cpp

341 lines
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/***************************************************************************
* Copyright (C) 2005 by Joris Guisson *
* joris.guisson@gmail.com *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. *
***************************************************************************/
#include <string.h>
#include <arpa/inet.h>
#include "sha1hashgen.h"
#include "functions.h"
namespace bt
{
static inline Uint32 LeftRotate(Uint32 x,Uint32 n)
{
return ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)));
}
SHA1HashGen::SHA1HashGen() : tmp_len(0),total_len(0)
{
}
SHA1HashGen::~SHA1HashGen()
{}
SHA1Hash SHA1HashGen::generate(const Uint8* data,Uint32 len)
{
h0 = 0x67452301;
h1 = 0xEFCDAB89;
h2 = 0x98BADCFE;
h3 = 0x10325476;
h4 = 0xC3D2E1F0;
Uint32 num_64_byte_chunks = len / 64;
Uint32 left_over = len % 64;
// proces regular data
for (Uint32 i = 0;i < num_64_byte_chunks;i++)
{
processChunk(data + (64*i));
}
// calculate the low and high byte of the data length
Uint32 total[2] = {0,0};
total[0] += len;
total[0] &= 0xFFFFFFFF;
if (total[0] < len)
total[1]++;
Uint32 high = ( total[0] >> 29 ) | ( total[1] << 3 );
Uint32 low = ( total[0] << 3 );
if (left_over == 0)
{
tmp[0] = 0x80;
for (Uint32 i = 1;i < 56;i++)
tmp[i] = 0;
// put in the length as 64-bit integer (BIG-ENDIAN)
WriteUint32(tmp,56,high);
WriteUint32(tmp,60,low);
// process the padding
processChunk(tmp);
}
else if (left_over < 56)
{
Uint32 off = num_64_byte_chunks * 64;
// copy left over bytes in tmp
memcpy(tmp,data + off, left_over);
tmp[left_over] = 0x80;
for (Uint32 i = left_over + 1;i < 56;i++)
tmp[i] = 0;
// put in the length as 64-bit integer (BIG-ENDIAN)
WriteUint32(tmp,56,high);
WriteUint32(tmp,60,low);
// process the padding
processChunk(tmp);
}
else
{
// now we need to process 2 chunks
Uint32 off = num_64_byte_chunks * 64;
// copy left over bytes in tmp
memcpy(tmp,data + off, left_over);
tmp[left_over] = 0x80;
for (Uint32 i = left_over + 1;i < 64;i++)
tmp[i] = 0;
// process first chunk
processChunk(tmp);
for (Uint32 i = 0;i < 56;i++)
tmp[i] = 0;
// put in the length as 64-bit integer (BIG-ENDIAN)
WriteUint32(tmp,56,high);
WriteUint32(tmp,60,low);
// process the second chunk
processChunk(tmp);
}
// construct final message
Uint8 hash[20];
WriteUint32(hash,0,h0);
WriteUint32(hash,4,h1);
WriteUint32(hash,8,h2);
WriteUint32(hash,12,h3);
WriteUint32(hash,16,h4);
return SHA1Hash(hash);
}
void SHA1HashGen::processChunk(const Uint8* chunk)
{
Uint32 w[80];
for (int i = 0;i < 80;i++)
{
if (i < 16)
{
w[i] = ntohl(*(const Uint32*)(chunk + (4*i)));
/* w[i] = (chunk[4*i] << 24) |
(chunk[4*i + 1] << 16) |
(chunk[4*i + 2] << 8) |
chunk[4*i + 3];
*/
}
else
{
w[i] = LeftRotate(w[i-3] ^ w[i-8] ^ w[i-14] ^ w[i-16],1);
}
}
Uint32 a = h0;
Uint32 b = h1;
Uint32 c = h2;
Uint32 d = h3;
Uint32 e = h4;
for (int i = 0;i < 80;i++)
{
Uint32 f,k;
if (i < 20)
{
f = (b & c) | ((~b) & d);
k = 0x5A827999;
}
else if (i < 40)
{
f = b ^ c ^ d;
k = 0x6ED9EBA1;
}
else if (i < 60)
{
f = (b & c) | (b & d) | (c & d);
k = 0x8F1BBCDC;
}
else
{
f = b ^ c ^ d;
k = 0xCA62C1D6;
}
Uint32 temp = LeftRotate(a,5) + f + e + k + w[i];
e = d;
d = c;
c = LeftRotate(b,30);
b = a;
a = temp;
}
h0 = (h0 + a) & 0xffffffff;
h1 = (h1 + b) & 0xffffffff;
h2 = (h2 + c) & 0xffffffff;
h3 = (h3 + d) & 0xffffffff;
h4 = (h4 + e) & 0xffffffff;
}
void SHA1HashGen::start()
{
h0 = 0x67452301;
h1 = 0xEFCDAB89;
h2 = 0x98BADCFE;
h3 = 0x10325476;
h4 = 0xC3D2E1F0;
tmp_len = total_len = 0;
memset(tmp,0,64);
}
void SHA1HashGen::update(const Uint8* data,Uint32 len)
{
if (tmp_len == 0)
{
Uint32 num_64_byte_chunks = len / 64;
Uint32 left_over = len % 64;
// proces data in chunks of 64 byte
for (Uint32 i = 0;i < num_64_byte_chunks;i++)
{
processChunk(data + (64*i));
}
if (left_over > 0)
{
// if there is anything left over, copy it in tmp
memcpy(tmp,data + (64 * num_64_byte_chunks),left_over);
tmp_len = left_over;
}
total_len += len;
}
else
{
if (tmp_len + len < 64)
{
// special case, not enough of data to fill tmp completely
memcpy(tmp + tmp_len,data,len);
tmp_len += len;
total_len += len;
}
else
{
// copy start of data in tmp and process it
Uint32 off = 64 - tmp_len;
memcpy(tmp + tmp_len,data, 64 - tmp_len);
processChunk(tmp);
tmp_len = 0;
Uint32 num_64_byte_chunks = (len - off) / 64;
Uint32 left_over = (len - off) % 64;
for (Uint32 i = 0;i < num_64_byte_chunks;i++)
{
processChunk(data + (off + (64*i)));
}
if (left_over > 0)
{
// if there is anything left over, copy it in tmp
memcpy(tmp,data + (off + 64 * num_64_byte_chunks),left_over);
tmp_len = left_over;
}
total_len += len;
}
}
}
void SHA1HashGen::end()
{
// calculate the low and high byte of the data length
Uint32 total[2] = {0,0};
total[0] += total_len;
total[0] &= 0xFFFFFFFF;
if (total[0] < total_len)
total[1]++;
Uint32 high = ( total[0] >> 29 ) | ( total[1] << 3 );
Uint32 low = ( total[0] << 3 );
if (tmp_len == 0)
{
tmp[0] = 0x80;
for (Uint32 i = 1;i < 56;i++)
tmp[i] = 0;
// put in the length as 64-bit integer (BIG-ENDIAN)
WriteUint32(tmp,56,high);
WriteUint32(tmp,60,low);
// process the padding
processChunk(tmp);
}
else if (tmp_len < 56)
{
tmp[tmp_len] = 0x80;
for (Uint32 i = tmp_len + 1;i < 56;i++)
tmp[i] = 0;
// put in the length as 64-bit integer (BIG-ENDIAN)
WriteUint32(tmp,56,high);
WriteUint32(tmp,60,low);
// process the padding
processChunk(tmp);
}
else
{
// now we need to process 2 chunks
tmp[tmp_len] = 0x80;
for (Uint32 i = tmp_len + 1;i < 56;i++)
tmp[i] = 0;
// process first chunk
processChunk(tmp);
for (Uint32 i = 0;i < 56;i++)
tmp[i] = 0;
// put in the length as 64-bit integer (BIG-ENDIAN)
WriteUint32(tmp,56,high);
WriteUint32(tmp,60,low);
// process the second chunk
processChunk(tmp);
}
}
SHA1Hash SHA1HashGen::get() const
{
// construct final message
Uint8 hash[20];
WriteUint32(hash,0,h0);
WriteUint32(hash,4,h1);
WriteUint32(hash,8,h2);
WriteUint32(hash,12,h3);
WriteUint32(hash,16,h4);
return SHA1Hash(hash);
}
}