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fixed line endings

This commit is contained in:
Arvid Norberg 2011-02-26 07:56:20 +00:00
parent ab3b82b8ee
commit 19e268bbe5
1 changed files with 371 additions and 371 deletions
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src/pe_crypto.cpp
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@ -1,371 +1,371 @@
/* /*
Copyright (c) 2007, Un Shyam & Arvid Norberg Copyright (c) 2007, Un Shyam & Arvid Norberg
All rights reserved. All rights reserved.
Redistribution and use in source and binary forms, with or without Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions modification, are permitted provided that the following conditions
are met: are met:
* Redistributions of source code must retain the above copyright * Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer. notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright * Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the distribution. the documentation and/or other materials provided with the distribution.
* Neither the name of the author nor the names of its * Neither the name of the author nor the names of its
contributors may be used to endorse or promote products derived contributors may be used to endorse or promote products derived
from this software without specific prior written permission. from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE. POSSIBILITY OF SUCH DAMAGE.
*/ */
#ifndef TORRENT_DISABLE_ENCRYPTION #ifndef TORRENT_DISABLE_ENCRYPTION
#include <boost/cstdint.hpp> #include <boost/cstdint.hpp>
#include <algorithm> #include <algorithm>
#if defined TORRENT_USE_GCRYPT #if defined TORRENT_USE_GCRYPT
#include <gcrypt.h> #include <gcrypt.h>
#elif defined TORRENT_USE_OPENSSL #elif defined TORRENT_USE_OPENSSL
#include <openssl/bn.h> #include <openssl/bn.h>
#include "libtorrent/random.hpp" #include "libtorrent/random.hpp"
#elif defined TORRENT_USE_TOMMATH #elif defined TORRENT_USE_TOMMATH
extern "C" { extern "C" {
#include "libtorrent/tommath.h" #include "libtorrent/tommath.h"
} }
#endif #endif
#include "libtorrent/pe_crypto.hpp" #include "libtorrent/pe_crypto.hpp"
#include "libtorrent/hasher.hpp" #include "libtorrent/hasher.hpp"
#include "libtorrent/assert.hpp" #include "libtorrent/assert.hpp"
namespace libtorrent namespace libtorrent
{ {
namespace namespace
{ {
const unsigned char dh_prime[96] = { const unsigned char dh_prime[96] = {
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC9, 0x0F, 0xDA, 0xA2, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC9, 0x0F, 0xDA, 0xA2,
0x21, 0x68, 0xC2, 0x34, 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1, 0x21, 0x68, 0xC2, 0x34, 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1,
0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, 0x02, 0x0B, 0xBE, 0xA6, 0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, 0x02, 0x0B, 0xBE, 0xA6,
0x3B, 0x13, 0x9B, 0x22, 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD, 0x3B, 0x13, 0x9B, 0x22, 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD,
0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, 0x30, 0x2B, 0x0A, 0x6D, 0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, 0x30, 0x2B, 0x0A, 0x6D,
0xF2, 0x5F, 0x14, 0x37, 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45, 0xF2, 0x5F, 0x14, 0x37, 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45,
0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, 0xF4, 0x4C, 0x42, 0xE9, 0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, 0xF4, 0x4C, 0x42, 0xE9,
0xA6, 0x3A, 0x36, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x09, 0x05, 0x63 0xA6, 0x3A, 0x36, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x09, 0x05, 0x63
}; };
} }
// Set the prime P and the generator, generate local public key // Set the prime P and the generator, generate local public key
dh_key_exchange::dh_key_exchange() dh_key_exchange::dh_key_exchange()
{ {
#ifdef TORRENT_USE_GCRYPT #ifdef TORRENT_USE_GCRYPT
// create local key // create local key
gcry_randomize(m_dh_local_secret, sizeof(m_dh_local_secret), GCRY_STRONG_RANDOM); gcry_randomize(m_dh_local_secret, sizeof(m_dh_local_secret), GCRY_STRONG_RANDOM);
// build gcrypt big ints from the prime and the secret // build gcrypt big ints from the prime and the secret
gcry_mpi_t prime = 0; gcry_mpi_t prime = 0;
gcry_mpi_t secret = 0; gcry_mpi_t secret = 0;
gcry_mpi_t key = 0; gcry_mpi_t key = 0;
gcry_error_t e; gcry_error_t e;
e = gcry_mpi_scan(&prime, GCRYMPI_FMT_USG, dh_prime, sizeof(dh_prime), 0); e = gcry_mpi_scan(&prime, GCRYMPI_FMT_USG, dh_prime, sizeof(dh_prime), 0);
if (e) goto get_out; if (e) goto get_out;
e = gcry_mpi_scan(&secret, GCRYMPI_FMT_USG, m_dh_local_secret, sizeof(m_dh_local_secret), 0); e = gcry_mpi_scan(&secret, GCRYMPI_FMT_USG, m_dh_local_secret, sizeof(m_dh_local_secret), 0);
if (e) goto get_out; if (e) goto get_out;
key = gcry_mpi_new(8); key = gcry_mpi_new(8);
// generator is 2 // generator is 2
gcry_mpi_set_ui(key, 2); gcry_mpi_set_ui(key, 2);
// key = (2 ^ secret) % prime // key = (2 ^ secret) % prime
gcry_mpi_powm(key, key, secret, prime); gcry_mpi_powm(key, key, secret, prime);
// key is now our local key // key is now our local key
size_t written; size_t written;
gcry_mpi_print(GCRYMPI_FMT_USG, (unsigned char*)m_dh_local_key gcry_mpi_print(GCRYMPI_FMT_USG, (unsigned char*)m_dh_local_key
, sizeof(m_dh_local_key), &written, key); , sizeof(m_dh_local_key), &written, key);
if (written < 96) if (written < 96)
{ {
memmove(m_dh_local_key + (sizeof(m_dh_local_key) - written), m_dh_local_key, written); memmove(m_dh_local_key + (sizeof(m_dh_local_key) - written), m_dh_local_key, written);
memset(m_dh_local_key, 0, sizeof(m_dh_local_key) - written); memset(m_dh_local_key, 0, sizeof(m_dh_local_key) - written);
} }
get_out: get_out:
if (key) gcry_mpi_release(key); if (key) gcry_mpi_release(key);
if (prime) gcry_mpi_release(prime); if (prime) gcry_mpi_release(prime);
if (secret) gcry_mpi_release(secret); if (secret) gcry_mpi_release(secret);
#elif defined TORRENT_USE_OPENSSL #elif defined TORRENT_USE_OPENSSL
// create local key // create local key
for (int i = 0; i < sizeof(m_dh_local_secret); ++i) for (int i = 0; i < sizeof(m_dh_local_secret); ++i)
m_dh_local_secret[i] = random(); m_dh_local_secret[i] = random();
BIGNUM* prime = 0; BIGNUM* prime = 0;
BIGNUM* secret = 0; BIGNUM* secret = 0;
BIGNUM* key = 0; BIGNUM* key = 0;
BN_CTX* ctx = 0; BN_CTX* ctx = 0;
int size; int size;
prime = BN_bin2bn(dh_prime, sizeof(dh_prime), 0); prime = BN_bin2bn(dh_prime, sizeof(dh_prime), 0);
if (prime == 0) goto get_out; if (prime == 0) goto get_out;
secret = BN_bin2bn((unsigned char*)m_dh_local_secret, sizeof(m_dh_local_secret), 0); secret = BN_bin2bn((unsigned char*)m_dh_local_secret, sizeof(m_dh_local_secret), 0);
if (secret == 0) goto get_out; if (secret == 0) goto get_out;
key = BN_new(); key = BN_new();
if (key == 0) goto get_out; if (key == 0) goto get_out;
// generator is 2 // generator is 2
BN_set_word(key, 2); BN_set_word(key, 2);
ctx = BN_CTX_new(); ctx = BN_CTX_new();
if (ctx == 0) goto get_out; if (ctx == 0) goto get_out;
BN_mod_exp(key, key, secret, prime, ctx); BN_mod_exp(key, key, secret, prime, ctx);
BN_CTX_free(ctx); BN_CTX_free(ctx);
// print key to m_dh_local_key // print key to m_dh_local_key
size = BN_num_bytes(key); size = BN_num_bytes(key);
memset(m_dh_local_key, 0, sizeof(m_dh_local_key) - size); memset(m_dh_local_key, 0, sizeof(m_dh_local_key) - size);
BN_bn2bin(key, (unsigned char*)m_dh_local_key + sizeof(m_dh_local_key) - size); BN_bn2bin(key, (unsigned char*)m_dh_local_key + sizeof(m_dh_local_key) - size);
get_out: get_out:
if (key) BN_free(key); if (key) BN_free(key);
if (secret) BN_free(secret); if (secret) BN_free(secret);
if (prime) BN_free(prime); if (prime) BN_free(prime);
#elif defined TORRENT_USE_TOMMATH #elif defined TORRENT_USE_TOMMATH
// create local key // create local key
for (int i = 0; i < int(sizeof(m_dh_local_secret)); ++i) for (int i = 0; i < int(sizeof(m_dh_local_secret)); ++i)
m_dh_local_secret[i] = random(); m_dh_local_secret[i] = random();
mp_int prime; mp_int prime;
mp_int secret; mp_int secret;
mp_int key; mp_int key;
int e; int e;
int size; int size;
mp_init(&prime); mp_init(&prime);
mp_init(&secret); mp_init(&secret);
mp_init(&key); mp_init(&key);
e = mp_read_unsigned_bin(&prime, dh_prime, sizeof(dh_prime)); e = mp_read_unsigned_bin(&prime, dh_prime, sizeof(dh_prime));
if (e) goto get_out; if (e) goto get_out;
e = mp_read_unsigned_bin(&secret, (unsigned char*)m_dh_local_secret, sizeof(m_dh_local_secret)); e = mp_read_unsigned_bin(&secret, (unsigned char*)m_dh_local_secret, sizeof(m_dh_local_secret));
if (e) goto get_out; if (e) goto get_out;
// generator is 2 // generator is 2
mp_set_int(&key, 2); mp_set_int(&key, 2);
// key = (2 ^ secret) % prime // key = (2 ^ secret) % prime
e = mp_exptmod(&key, &secret, &prime, &key); e = mp_exptmod(&key, &secret, &prime, &key);
if (e) goto get_out; if (e) goto get_out;
// key is now our local key // key is now our local key
size = mp_unsigned_bin_size(&key); size = mp_unsigned_bin_size(&key);
memset(m_dh_local_key, 0, sizeof(m_dh_local_key) - size); memset(m_dh_local_key, 0, sizeof(m_dh_local_key) - size);
mp_to_unsigned_bin(&key, (unsigned char*)m_dh_local_key + sizeof(m_dh_local_key) - size); mp_to_unsigned_bin(&key, (unsigned char*)m_dh_local_key + sizeof(m_dh_local_key) - size);
get_out: get_out:
mp_clear(&key); mp_clear(&key);
mp_clear(&prime); mp_clear(&prime);
mp_clear(&secret); mp_clear(&secret);
#else #else
#error you must define which bigint library to use #error you must define which bigint library to use
#endif #endif
} }
char const* dh_key_exchange::get_local_key() const char const* dh_key_exchange::get_local_key() const
{ {
return m_dh_local_key; return m_dh_local_key;
} }
// compute shared secret given remote public key // compute shared secret given remote public key
int dh_key_exchange::compute_secret(char const* remote_pubkey) int dh_key_exchange::compute_secret(char const* remote_pubkey)
{ {
TORRENT_ASSERT(remote_pubkey); TORRENT_ASSERT(remote_pubkey);
int ret = 0; int ret = 0;
#ifdef TORRENT_USE_GCRYPT #ifdef TORRENT_USE_GCRYPT
gcry_mpi_t prime = 0; gcry_mpi_t prime = 0;
gcry_mpi_t remote_key = 0; gcry_mpi_t remote_key = 0;
gcry_mpi_t secret = 0; gcry_mpi_t secret = 0;
size_t written; size_t written;
gcry_error_t e; gcry_error_t e;
e = gcry_mpi_scan(&prime, GCRYMPI_FMT_USG, dh_prime, sizeof(dh_prime), 0); e = gcry_mpi_scan(&prime, GCRYMPI_FMT_USG, dh_prime, sizeof(dh_prime), 0);
if (e != 0) { ret = 1; goto get_out; } if (e != 0) { ret = 1; goto get_out; }
e = gcry_mpi_scan(&remote_key, GCRYMPI_FMT_USG, remote_pubkey, 96, 0); e = gcry_mpi_scan(&remote_key, GCRYMPI_FMT_USG, remote_pubkey, 96, 0);
if (e != 0) { ret = 1; goto get_out; } if (e != 0) { ret = 1; goto get_out; }
e = gcry_mpi_scan(&secret, GCRYMPI_FMT_USG, (unsigned char const*)m_dh_local_secret e = gcry_mpi_scan(&secret, GCRYMPI_FMT_USG, (unsigned char const*)m_dh_local_secret
, sizeof(m_dh_local_secret), 0); , sizeof(m_dh_local_secret), 0);
if (e != 0) { ret = 1; goto get_out; } if (e != 0) { ret = 1; goto get_out; }
gcry_mpi_powm(remote_key, remote_key, secret, prime); gcry_mpi_powm(remote_key, remote_key, secret, prime);
// remote_key is now the shared secret // remote_key is now the shared secret
e = gcry_mpi_print(GCRYMPI_FMT_USG, (unsigned char*)m_dh_shared_secret e = gcry_mpi_print(GCRYMPI_FMT_USG, (unsigned char*)m_dh_shared_secret
, sizeof(m_dh_shared_secret), &written, remote_key); , sizeof(m_dh_shared_secret), &written, remote_key);
if (e != 0) { ret = 1; goto get_out; } if (e != 0) { ret = 1; goto get_out; }
if (written < 96) if (written < 96)
{ {
memmove(m_dh_shared_secret, m_dh_shared_secret memmove(m_dh_shared_secret, m_dh_shared_secret
+ (sizeof(m_dh_shared_secret) - written), written); + (sizeof(m_dh_shared_secret) - written), written);
memset(m_dh_shared_secret, 0, sizeof(m_dh_shared_secret) - written); memset(m_dh_shared_secret, 0, sizeof(m_dh_shared_secret) - written);
} }
get_out: get_out:
if (prime) gcry_mpi_release(prime); if (prime) gcry_mpi_release(prime);
if (remote_key) gcry_mpi_release(remote_key); if (remote_key) gcry_mpi_release(remote_key);
if (secret) gcry_mpi_release(secret); if (secret) gcry_mpi_release(secret);
#elif defined TORRENT_USE_OPENSSL #elif defined TORRENT_USE_OPENSSL
BIGNUM* prime = 0; BIGNUM* prime = 0;
BIGNUM* secret = 0; BIGNUM* secret = 0;
BIGNUM* remote_key = 0; BIGNUM* remote_key = 0;
BN_CTX* ctx = 0; BN_CTX* ctx = 0;
int size; int size;
prime = BN_bin2bn(dh_prime, sizeof(dh_prime), 0); prime = BN_bin2bn(dh_prime, sizeof(dh_prime), 0);
if (prime == 0) { ret = 1; goto get_out; } if (prime == 0) { ret = 1; goto get_out; }
secret = BN_bin2bn((unsigned char*)m_dh_local_secret, sizeof(m_dh_local_secret), 0); secret = BN_bin2bn((unsigned char*)m_dh_local_secret, sizeof(m_dh_local_secret), 0);
if (secret == 0) { ret = 1; goto get_out; } if (secret == 0) { ret = 1; goto get_out; }
remote_key = BN_bin2bn((unsigned char*)remote_pubkey, 96, 0); remote_key = BN_bin2bn((unsigned char*)remote_pubkey, 96, 0);
if (remote_key == 0) { ret = 1; goto get_out; } if (remote_key == 0) { ret = 1; goto get_out; }
ctx = BN_CTX_new(); ctx = BN_CTX_new();
if (ctx == 0) { ret = 1; goto get_out; } if (ctx == 0) { ret = 1; goto get_out; }
BN_mod_exp(remote_key, remote_key, secret, prime, ctx); BN_mod_exp(remote_key, remote_key, secret, prime, ctx);
BN_CTX_free(ctx); BN_CTX_free(ctx);
// remote_key is now the shared secret // remote_key is now the shared secret
size = BN_num_bytes(remote_key); size = BN_num_bytes(remote_key);
memset(m_dh_shared_secret, 0, sizeof(m_dh_shared_secret) - size); memset(m_dh_shared_secret, 0, sizeof(m_dh_shared_secret) - size);
BN_bn2bin(remote_key, (unsigned char*)m_dh_shared_secret + sizeof(m_dh_shared_secret) - size); BN_bn2bin(remote_key, (unsigned char*)m_dh_shared_secret + sizeof(m_dh_shared_secret) - size);
get_out: get_out:
BN_free(remote_key); BN_free(remote_key);
BN_free(secret); BN_free(secret);
BN_free(prime); BN_free(prime);
#elif defined TORRENT_USE_TOMMATH #elif defined TORRENT_USE_TOMMATH
mp_int prime; mp_int prime;
mp_int secret; mp_int secret;
mp_int remote_key; mp_int remote_key;
int size; int size;
int e; int e;
mp_init(&prime); mp_init(&prime);
mp_init(&secret); mp_init(&secret);
mp_init(&remote_key); mp_init(&remote_key);
e = mp_read_unsigned_bin(&prime, dh_prime, sizeof(dh_prime)); e = mp_read_unsigned_bin(&prime, dh_prime, sizeof(dh_prime));
if (e) { ret = 1; goto get_out; } if (e) { ret = 1; goto get_out; }
e = mp_read_unsigned_bin(&secret, (unsigned char*)m_dh_local_secret, sizeof(m_dh_local_secret)); e = mp_read_unsigned_bin(&secret, (unsigned char*)m_dh_local_secret, sizeof(m_dh_local_secret));
if (e) { ret = 1; goto get_out; } if (e) { ret = 1; goto get_out; }
e = mp_read_unsigned_bin(&remote_key, (unsigned char*)remote_pubkey, 96); e = mp_read_unsigned_bin(&remote_key, (unsigned char*)remote_pubkey, 96);
if (e) { ret = 1; goto get_out; } if (e) { ret = 1; goto get_out; }
e = mp_exptmod(&remote_key, &secret, &prime, &remote_key); e = mp_exptmod(&remote_key, &secret, &prime, &remote_key);
if (e) goto get_out; if (e) goto get_out;
// remote_key is now the shared secret // remote_key is now the shared secret
size = mp_unsigned_bin_size(&remote_key); size = mp_unsigned_bin_size(&remote_key);
memset(m_dh_shared_secret, 0, sizeof(m_dh_shared_secret) - size); memset(m_dh_shared_secret, 0, sizeof(m_dh_shared_secret) - size);
mp_to_unsigned_bin(&remote_key, (unsigned char*)m_dh_shared_secret + sizeof(m_dh_shared_secret) - size); mp_to_unsigned_bin(&remote_key, (unsigned char*)m_dh_shared_secret + sizeof(m_dh_shared_secret) - size);
get_out: get_out:
mp_clear(&remote_key); mp_clear(&remote_key);
mp_clear(&secret); mp_clear(&secret);
mp_clear(&prime); mp_clear(&prime);
#else #else
#error you must define which bigint library to use #error you must define which bigint library to use
#endif #endif
// calculate the xor mask for the obfuscated hash // calculate the xor mask for the obfuscated hash
hasher h; hasher h;
h.update("req3", 4); h.update("req3", 4);
h.update(m_dh_shared_secret, sizeof(m_dh_shared_secret)); h.update(m_dh_shared_secret, sizeof(m_dh_shared_secret));
m_xor_mask = h.final(); m_xor_mask = h.final();
return ret; return ret;
} }
} // namespace libtorrent } // namespace libtorrent
#if !defined TORRENT_USE_OPENSSL && !defined TORRENT_USE_GCRYPT #if !defined TORRENT_USE_OPENSSL && !defined TORRENT_USE_GCRYPT
// All this code is based on libTomCrypt (http://www.libtomcrypt.com/) // All this code is based on libTomCrypt (http://www.libtomcrypt.com/)
// this library is public domain and has been specially // this library is public domain and has been specially
// tailored for libtorrent by Arvid Norberg // tailored for libtorrent by Arvid Norberg
void rc4_init(const unsigned char* in, unsigned long len, rc4 *state) void rc4_init(const unsigned char* in, unsigned long len, rc4 *state)
{ {
unsigned char key[256], tmp, *s; unsigned char key[256], tmp, *s;
int keylen, x, y, j; int keylen, x, y, j;
TORRENT_ASSERT(state != 0); TORRENT_ASSERT(state != 0);
TORRENT_ASSERT(len <= 256); TORRENT_ASSERT(len <= 256);
state->x = 0; state->x = 0;
while (len--) { while (len--) {
state->buf[state->x++] = *in++; state->buf[state->x++] = *in++;
} }
/* extract the key */ /* extract the key */
s = state->buf; s = state->buf;
memcpy(key, s, 256); memcpy(key, s, 256);
keylen = state->x; keylen = state->x;
/* make RC4 perm and shuffle */ /* make RC4 perm and shuffle */
for (x = 0; x < 256; x++) { for (x = 0; x < 256; x++) {
s[x] = x; s[x] = x;
} }
for (j = x = y = 0; x < 256; x++) { for (j = x = y = 0; x < 256; x++) {
y = (y + state->buf[x] + key[j++]) & 255; y = (y + state->buf[x] + key[j++]) & 255;
if (j == keylen) { if (j == keylen) {
j = 0; j = 0;
} }
tmp = s[x]; s[x] = s[y]; s[y] = tmp; tmp = s[x]; s[x] = s[y]; s[y] = tmp;
} }
state->x = 0; state->x = 0;
state->y = 0; state->y = 0;
} }
unsigned long rc4_encrypt(unsigned char *out, unsigned long outlen, rc4 *state) unsigned long rc4_encrypt(unsigned char *out, unsigned long outlen, rc4 *state)
{ {
unsigned char x, y, *s, tmp; unsigned char x, y, *s, tmp;
unsigned long n; unsigned long n;
TORRENT_ASSERT(out != 0); TORRENT_ASSERT(out != 0);
TORRENT_ASSERT(state != 0); TORRENT_ASSERT(state != 0);
n = outlen; n = outlen;
x = state->x; x = state->x;
y = state->y; y = state->y;
s = state->buf; s = state->buf;
while (outlen--) { while (outlen--) {
x = (x + 1) & 255; x = (x + 1) & 255;
y = (y + s[x]) & 255; y = (y + s[x]) & 255;
tmp = s[x]; s[x] = s[y]; s[y] = tmp; tmp = s[x]; s[x] = s[y]; s[y] = tmp;
tmp = (s[x] + s[y]) & 255; tmp = (s[x] + s[y]) & 255;
*out++ ^= s[tmp]; *out++ ^= s[tmp];
} }
state->x = x; state->x = x;
state->y = y; state->y = y;
return n; return n;
} }
#endif #endif
#endif // #ifndef TORRENT_DISABLE_ENCRYPTION #endif // #ifndef TORRENT_DISABLE_ENCRYPTION