static tau_transaction_t
tau_transaction_new( void )
{
tau_transaction_t tmp;
tr_cryptoRandBuf( &tmp, sizeof( tau_transaction_t ) );
return tmp;
}
char*
tr_ssha1( const void * plaintext )
{
enum { saltval_len = 8,
salter_len = 64 };
static const char * salter = "0123456789"
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"./";
size_t i;
unsigned char salt[saltval_len];
uint8_t sha[SHA_DIGEST_LENGTH];
char buf[2*SHA_DIGEST_LENGTH + saltval_len + 2];
tr_cryptoRandBuf( salt, saltval_len );
for( i=0; i<saltval_len; ++i )
salt[i] = salter[ salt[i] % salter_len ];
tr_sha1( sha, plaintext, strlen( plaintext ), salt, saltval_len, NULL );
tr_sha1_to_hex( &buf[1], sha );
memcpy( &buf[1+2*SHA_DIGEST_LENGTH], &salt, saltval_len );
buf[1+2*SHA_DIGEST_LENGTH + saltval_len] = '\0';
buf[0] = '{'; /* signal that this is a hash. this makes saving/restoring
easier */
return tr_strdup( &buf );
}
static int
readYa( tr_handshake * handshake,
struct evbuffer * inbuf )
{
uint8_t ya[KEY_LEN];
uint8_t * walk, outbuf[KEY_LEN + PadB_MAXLEN];
const uint8_t *myKey, *secret;
int len;
dbgmsg( handshake, "in readYa... need %d, have %zu",
KEY_LEN, evbuffer_get_length( inbuf ) );
if( evbuffer_get_length( inbuf ) < KEY_LEN )
return READ_LATER;
/* read the incoming peer's public key */
evbuffer_remove( inbuf, ya, KEY_LEN );
secret = tr_cryptoComputeSecret( handshake->crypto, ya );
memcpy( handshake->mySecret, secret, KEY_LEN );
tr_sha1( handshake->myReq1, "req1", 4, secret, KEY_LEN, NULL );
dbgmsg( handshake, "sending B->A: Diffie Hellman Yb, PadB" );
/* send our public key to the peer */
walk = outbuf;
myKey = tr_cryptoGetMyPublicKey( handshake->crypto, &len );
memcpy( walk, myKey, len );
walk += len;
len = tr_cryptoRandInt( PadB_MAXLEN );
tr_cryptoRandBuf( walk, len );
walk += len;
setReadState( handshake, AWAITING_PAD_A );
tr_peerIoWriteBytes( handshake->io, outbuf, walk - outbuf, FALSE );
return READ_NOW;
}
/* 1 A->B: Diffie Hellman Ya, PadA */
static void
sendYa( tr_handshake * handshake )
{
int len;
const uint8_t * public_key;
char outbuf[ KEY_LEN + PadA_MAXLEN ], *walk=outbuf;
/* add our public key (Ya) */
public_key = tr_cryptoGetMyPublicKey( handshake->crypto, &len );
assert( len == KEY_LEN );
assert( public_key );
memcpy( walk, public_key, len );
walk += len;
/* add some bullshit padding */
len = tr_cryptoRandInt( PadA_MAXLEN );
tr_cryptoRandBuf( walk, len );
walk += len;
/* send it */
setReadState( handshake, AWAITING_YB );
tr_peerIoWriteBytes( handshake->io, outbuf, walk - outbuf, FALSE );
}
int
tr_dhtInit(tr_session *ss, const tr_address * tr_addr)
{
struct sockaddr_in sin;
tr_benc benc;
int rc;
tr_bool have_id = FALSE;
char * dat_file;
uint8_t * nodes = NULL, * nodes6 = NULL;
const uint8_t * raw;
size_t len, len6;
struct bootstrap_closure * cl;
if( session ) /* already initialized */
return -1;
dht_port = tr_sessionGetPeerPort(ss);
if(dht_port <= 0)
return -1;
tr_ndbg( "DHT", "Initializing DHT" );
dht_socket = socket(PF_INET, SOCK_DGRAM, 0);
if(dht_socket < 0)
goto fail;
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
memcpy(&sin.sin_addr, &tr_addr->addr.addr4, sizeof (struct in_addr));
sin.sin_port = htons(dht_port);
rc = bind(dht_socket, (struct sockaddr*)&sin, sizeof(sin));
if(rc < 0)
goto fail;
if(tr_globalIPv6())
rebind_ipv6(TRUE);
if( getenv( "TR_DHT_VERBOSE" ) != NULL )
dht_debug = stderr;
dat_file = tr_buildPath( ss->configDir, "dht.dat", NULL );
rc = tr_bencLoadFile( &benc, TR_FMT_BENC, dat_file );
tr_free( dat_file );
if(rc == 0) {
have_id = tr_bencDictFindRaw(&benc, "id", &raw, &len);
if( have_id && len==20 )
memcpy( myid, raw, len );
if( dht_socket >= 0 &&
tr_bencDictFindRaw( &benc, "nodes", &raw, &len ) && !(len%6) ) {
nodes = tr_memdup( raw, len );
}
if( dht6_socket > 0 &&
tr_bencDictFindRaw( &benc, "nodes6", &raw, &len6 ) && !(len6%18) ) {
nodes6 = tr_memdup( raw, len6 );
}
tr_bencFree( &benc );
}
if(nodes == NULL)
len = 0;
if(nodes6 == NULL)
len6 = 0;
if( have_id )
tr_ninf( "DHT", "Reusing old id" );
else {
/* Note that DHT ids need to be distributed uniformly,
* so it should be something truly random. */
tr_ninf( "DHT", "Generating new id" );
tr_cryptoRandBuf( myid, 20 );
}
rc = dht_init( dht_socket, dht6_socket, myid, NULL );
if( rc < 0 )
goto fail;
session = ss;
cl = tr_new( struct bootstrap_closure, 1 );
cl->session = session;
cl->nodes = nodes;
cl->nodes6 = nodes6;
cl->len = len;
cl->len6 = len6;
tr_threadNew( dht_bootstrap, cl );
dht_event = event_new( session->event_base, dht_socket, EV_READ, event_callback, NULL );
tr_timerAdd( dht_event, 0, tr_cryptoWeakRandInt( 1000000 ) );
if( dht6_socket >= 0 )
{
dht6_event = event_new( session->event_base, dht6_socket, EV_READ, event_callback, NULL );
tr_timerAdd( dht6_event, 0, tr_cryptoWeakRandInt( 1000000 ) );
}
tr_ndbg( "DHT", "DHT initialized" );
return 1;
fail:
{
const int save = errno;
close(dht_socket);
if( dht6_socket >= 0 )
close(dht6_socket);
dht_socket = dht6_socket = -1;
session = NULL;
tr_ndbg( "DHT", "DHT initialization failed (errno = %d)", save );
errno = save;
}
return -1;
}
int
tr_dhtInit(tr_session *ss)
{
tr_benc benc;
int rc;
bool have_id = false;
char * dat_file;
uint8_t * nodes = NULL, * nodes6 = NULL;
const uint8_t * raw;
size_t len, len6;
struct bootstrap_closure * cl;
if( session ) /* already initialized */
return -1;
tr_ndbg( "DHT", "Initializing DHT" );
if( getenv( "TR_DHT_VERBOSE" ) != NULL )
dht_debug = stderr;
dat_file = tr_buildPath( ss->configDir, "dht.dat", NULL );
rc = tr_bencLoadFile( &benc, TR_FMT_BENC, dat_file );
tr_free( dat_file );
if(rc == 0) {
have_id = tr_bencDictFindRaw(&benc, "id", &raw, &len);
if( have_id && len==20 )
memcpy( myid, raw, len );
if( ss->udp_socket >= 0 &&
tr_bencDictFindRaw( &benc, "nodes", &raw, &len ) && !(len%6) ) {
nodes = tr_memdup( raw, len );
}
if( ss->udp6_socket > 0 &&
tr_bencDictFindRaw( &benc, "nodes6", &raw, &len6 ) && !(len6%18) ) {
nodes6 = tr_memdup( raw, len6 );
}
tr_bencFree( &benc );
}
if(nodes == NULL)
len = 0;
if(nodes6 == NULL)
len6 = 0;
if( have_id )
tr_ninf( "DHT", "Reusing old id" );
else {
/* Note that DHT ids need to be distributed uniformly,
* so it should be something truly random. */
tr_ninf( "DHT", "Generating new id" );
tr_cryptoRandBuf( myid, 20 );
}
rc = dht_init( ss->udp_socket, ss->udp6_socket, myid, NULL );
if( rc < 0 )
goto fail;
session = ss;
cl = tr_new( struct bootstrap_closure, 1 );
cl->session = session;
cl->nodes = nodes;
cl->nodes6 = nodes6;
cl->len = len;
cl->len6 = len6;
tr_threadNew( dht_bootstrap, cl );
dht_timer = evtimer_new( session->event_base, timer_callback, session );
tr_timerAdd( dht_timer, 0, tr_cryptoWeakRandInt( 1000000 ) );
tr_ndbg( "DHT", "DHT initialized" );
return 1;
fail:
tr_ndbg( "DHT", "DHT initialization failed (errno = %d)", errno );
session = NULL;
return -1;
}