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pcloudcc-lneely/pCloudCC/lib/pclsync/pp2p.c

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/* Copyright (c) 2014 Anton Titov.
* Copyright (c) 2014 pCloud Ltd.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of pCloud Ltd nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL pCloud Ltd BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN 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 POSSIBILITY OF SUCH DAMAGE.
*/
#include "pcompat.h"
#include "psettings.h"
#include "plibs.h"
#include "ptimer.h"
#include "pstatus.h"
#include "pssl.h"
#include "pdownload.h"
#include "pnetlibs.h"
#include "papi.h"
#include "pp2p.h"
#include "pcrypto.h"
#include "pfolder.h"
#include <string.h>
#define P2P_ENCTYPE_RSA_AES 0
typedef uint32_t packet_type_t;
typedef uint32_t packet_id_t;
typedef uint32_t packet_resp_t;
typedef PSYNC_PACKED_STRUCT {
packet_type_t type;
unsigned char hashstart[4];
uint64_t filesize;
unsigned char rand[PSYNC_HASH_BLOCK_SIZE-PSYNC_HASH_DIGEST_HEXLEN];
unsigned char genhash[PSYNC_HASH_DIGEST_HEXLEN];
unsigned char computername[PSYNC_HASH_DIGEST_HEXLEN];
} packet_check;
typedef PSYNC_PACKED_STRUCT {
packet_resp_t type;
uint32_t port;
unsigned char rand[PSYNC_HASH_BLOCK_SIZE-PSYNC_HASH_DIGEST_HEXLEN];
unsigned char genhash[PSYNC_HASH_DIGEST_HEXLEN];
} packet_check_resp;
typedef PSYNC_PACKED_STRUCT {
packet_type_t type;
unsigned char hashstart[4];
uint64_t filesize;
uint32_t keylen;
uint32_t tokenlen;
unsigned char rand[PSYNC_HASH_BLOCK_SIZE-PSYNC_HASH_DIGEST_HEXLEN];
unsigned char genhash[PSYNC_HASH_DIGEST_HEXLEN];
unsigned char computername[PSYNC_HASH_DIGEST_HEXLEN];
} packet_get;
static const int on=1;
static const size_t min_packet_size[]={
#define P2P_WAKE 0
sizeof(packet_type_t),
#define P2P_CHECK 1
sizeof(packet_check),
#define P2P_GET 2
sizeof(packet_get)
};
#define P2P_RESP_NOPE 0
#define P2P_RESP_HAVEIT 1
#define P2P_RESP_WAIT 2
static pthread_mutex_t p2pmutex=PTHREAD_MUTEX_INITIALIZER;
static psync_socket_t udpsock;
static int files_serving=0;
static int running=0;
static int tcpport;
static char computername[PSYNC_HASH_DIGEST_HEXLEN];
static const uint32_t requiredstatuses[]={
PSTATUS_COMBINE(PSTATUS_TYPE_AUTH, PSTATUS_AUTH_PROVIDED),
PSTATUS_COMBINE(PSTATUS_TYPE_RUN, PSTATUS_RUN_RUN),
PSTATUS_COMBINE(PSTATUS_TYPE_ONLINE, PSTATUS_ONLINE_ONLINE)
};
static struct sockaddr_storage paddr;
static socklen_t paddrlen;
static psync_rsa_publickey_t psync_rsa_public=PSYNC_INVALID_RSA;
static psync_rsa_privatekey_t psync_rsa_private=PSYNC_INVALID_RSA;
static psync_binary_rsa_key_t psync_rsa_public_bin=PSYNC_INVALID_BIN_RSA;
PSYNC_PURE static const char *p2p_get_address(void *addr){
if (((struct sockaddr_in *)addr)->sin_family==AF_INET)
return inet_ntoa(((struct sockaddr_in *)addr)->sin_addr);
else{
#if defined(P_OS_POSIX)
static char buff[80];
return inet_ntop(AF_INET6, &((struct sockaddr_in6 *)addr)->sin6_addr, buff, sizeof(buff));
#else
return "IPv6 address"; /* inet_ntop on Windows is Vista+ */
#endif
}
}
PSYNC_PURE static const char *p2p_get_peer_address(){
if (paddr.ss_family==AF_INET)
return inet_ntoa(((struct sockaddr_in *)&paddr)->sin_addr);
else{
#if defined(P_OS_POSIX)
static char buff[80];
return inet_ntop(AF_INET6, &((struct sockaddr_in6 *)&paddr)->sin6_addr, buff, sizeof(buff));
#else
return "IPv6 address"; /* inet_ntop on Windows is Vista+ */
#endif
}
}
static psync_fileid_t psync_p2p_has_file(const unsigned char *hashstart, const unsigned char *genhash, const unsigned char *rand, uint64_t filesize,
unsigned char *realhash){
psync_sql_res *res;
psync_variant_row row;
psync_fileid_t ret;
unsigned char hashsource[PSYNC_HASH_BLOCK_SIZE], hashbin[PSYNC_HASH_DIGEST_LEN], hashhex[PSYNC_HASH_DIGEST_HEXLEN];
char like[PSYNC_P2P_HEXHASH_BYTES+1];
memcpy(like, hashstart, PSYNC_P2P_HEXHASH_BYTES);
like[PSYNC_P2P_HEXHASH_BYTES]='%';
memcpy(hashsource+PSYNC_HASH_DIGEST_HEXLEN, rand, PSYNC_HASH_BLOCK_SIZE-PSYNC_HASH_DIGEST_HEXLEN);
res=psync_sql_query_rdlock("SELECT id, checksum FROM localfile WHERE checksum LIKE ? AND size=?");
psync_sql_bind_lstring(res, 1, like, PSYNC_P2P_HEXHASH_BYTES+1);
psync_sql_bind_uint(res, 2, filesize);
while ((row=psync_sql_fetch_row(res))){
assertw(row[1].type==PSYNC_TSTRING && row[1].length==PSYNC_HASH_DIGEST_HEXLEN);
memcpy(hashsource, row[1].str, PSYNC_HASH_DIGEST_HEXLEN);
psync_hash(hashsource, PSYNC_HASH_BLOCK_SIZE, hashbin);
psync_binhex(hashhex, hashbin, PSYNC_HASH_DIGEST_LEN);
if (!memcmp(hashhex, genhash, PSYNC_HASH_DIGEST_HEXLEN)){
if (realhash)
memcpy(realhash, row[1].str, PSYNC_HASH_DIGEST_HEXLEN);
ret=psync_get_number(row[0]);
psync_sql_free_result(res);
return ret;
}
}
psync_sql_free_result(res);
return 0;
}
static int psync_p2p_is_downloading(const unsigned char *hashstart, const unsigned char *genhash, const unsigned char *rand, uint64_t filesize,
unsigned char *realhash){
downloading_files_hashes *hashes;
unsigned char hashsource[PSYNC_HASH_BLOCK_SIZE], hashbin[PSYNC_HASH_DIGEST_LEN], hashhex[PSYNC_HASH_DIGEST_HEXLEN];
size_t i;
hashes=psync_get_downloading_hashes();
for (i=0; i<hashes->hashcnt; i++){
if (memcmp(hashstart, hashes->hashes[i], PSYNC_P2P_HEXHASH_BYTES))
continue;
memcpy(hashsource, hashes->hashes[i], PSYNC_HASH_DIGEST_HEXLEN);
memcpy(hashsource+PSYNC_HASH_DIGEST_HEXLEN, rand, PSYNC_HASH_BLOCK_SIZE-PSYNC_HASH_DIGEST_HEXLEN);
psync_hash(hashsource, PSYNC_HASH_BLOCK_SIZE, hashbin);
psync_binhex(hashhex, hashbin, PSYNC_HASH_DIGEST_LEN);
if (!memcmp(hashhex, genhash, PSYNC_HASH_DIGEST_HEXLEN)){
if (realhash)
memcpy(realhash, hashsource, PSYNC_HASH_DIGEST_HEXLEN);
psync_free(hashes);
return 1;
}
}
psync_free(hashes);
return 0;
}
static void psync_p2p_check(const packet_check *packet){
unsigned char hashhex[PSYNC_HASH_DIGEST_HEXLEN], hashsource[PSYNC_HASH_BLOCK_SIZE], hashbin[PSYNC_HASH_DIGEST_LEN];
packet_check_resp resp;
if (!memcmp(packet->computername, computername, PSYNC_HASH_DIGEST_HEXLEN))
return;
if (psync_p2p_has_file(packet->hashstart, packet->genhash, packet->rand, packet->filesize, hashhex))
resp.type=P2P_RESP_HAVEIT;
else if (psync_p2p_is_downloading(packet->hashstart, packet->genhash, packet->rand, packet->filesize, hashhex))
resp.type=P2P_RESP_WAIT;
else
return;
resp.port=tcpport;
psync_ssl_rand_weak(resp.rand, sizeof(resp.rand));
memcpy(hashsource, hashhex, PSYNC_HASH_DIGEST_HEXLEN);
memcpy(hashsource+PSYNC_HASH_DIGEST_HEXLEN, resp.rand, sizeof(resp.rand));
psync_hash(hashsource, PSYNC_HASH_BLOCK_SIZE, hashbin);
psync_binhex(resp.genhash, hashbin, PSYNC_HASH_DIGEST_LEN);
debug(D_NOTICE, "replying with %u to a check from %s, looking for %."NTO_STR(PSYNC_HASH_DIGEST_HEXLEN)"s", (unsigned int)resp.type, p2p_get_peer_address(), hashhex);
if (files_serving)
psync_milisleep(files_serving*10);
if (resp.type==P2P_RESP_WAIT)
psync_milisleep(PSYNC_P2P_INITIAL_TIMEOUT/4);
if (!sendto(udpsock, (const char *)&resp, sizeof(resp), 0, (const struct sockaddr *)&paddr, paddrlen))
debug(D_WARNING, "sendto to %s failed", p2p_get_peer_address());
}
static void psync_p2p_process_packet(const char *packet, size_t plen){
packet_type_t type;
if (unlikely(plen<sizeof(packet_type_t)))
return;
type=*((packet_type_t *)packet);
if (type>=ARRAY_SIZE(min_packet_size) || min_packet_size[type]>plen)
return;
debug(D_NOTICE, "got %u packet from %s", (unsigned int)type, p2p_get_peer_address());
switch (type){
case P2P_WAKE:
break;
case P2P_CHECK:
psync_p2p_check((packet_check *)packet);
debug(D_NOTICE, "processed P2P packed");
break;
default:
debug(D_BUG, "handler for packet type %u not implemented", (unsigned)type);
break;
}
}
static int socket_write_all(psync_socket_t sock, const void *buff, size_t len){
ssize_t ret;
while (len){
ret=psync_write_socket(sock, buff, len);
if (ret==SOCKET_ERROR){
if (psync_sock_err()==P_INTR || psync_sock_err()==P_AGAIN || psync_sock_err()==P_WOULDBLOCK)
continue;
return -1;
}
buff=(const char *)buff+ret;
len-=ret;
}
return 0;
}
static int socket_read_all(psync_socket_t sock, void *buff, size_t len){
ssize_t ret;
while (len){
ret=psync_read_socket(sock, buff, len);
if (ret==SOCKET_ERROR){
if (psync_sock_err()==P_INTR || psync_sock_err()==P_AGAIN || psync_sock_err()==P_WOULDBLOCK)
continue;
return -1;
}
else if (ret==0)
return -1;
buff=(char *)buff+ret;
len-=ret;
}
return 0;
}
static int check_token(char *token, uint32_t tlen, unsigned char *key, uint32_t keylen, unsigned char *hashhex){
binparam params[]={P_LSTR(PSYNC_CHECKSUM, hashhex, PSYNC_HASH_DIGEST_HEXLEN),
P_LSTR("keydata", key, keylen), P_LSTR("token", token, tlen)};
psync_socket *api;
binresult *res;
uint64_t result;
api=psync_apipool_get();
if (unlikely_log(!api))
return 0;
res=send_command(api, "checkfileownershiptoken", params);
if (unlikely_log(!res)){
psync_apipool_release_bad(api);
return 0;
}
psync_apipool_release(api);
result=psync_find_result(res, "result", PARAM_NUM)->num;
psync_free(res);
return result?0:1;
}
static void psync_p2p_tcphandler(void *ptr){
packet_get packet;
psync_fileid_t localfileid;
psync_binary_rsa_key_t binpubrsa;
psync_rsa_publickey_t pubrsa;
psync_symmetric_key_t aeskey;
psync_encrypted_symmetric_key_t encaeskey;
psync_crypto_aes256_ctr_encoder_decoder_t encoder;
char *token, *localpath;
uint64_t off;
size_t rd;
psync_socket_t sock;
psync_file_t fd;
uint32_t keylen, enctype;
unsigned char hashhex[PSYNC_HASH_DIGEST_HEXLEN], buff[4096];
sock=*((psync_socket_t *)ptr);
psync_free(ptr);
debug(D_NOTICE, "got tcp connection");
if (unlikely_log(socket_read_all(sock, &packet, sizeof(packet))))
goto err0;
if (unlikely_log(packet.keylen>PSYNC_P2P_RSA_SIZE) || unlikely_log(packet.tokenlen>512)) /* lets allow 8 times larger keys than we use */
goto err0;
localfileid=psync_p2p_has_file(packet.hashstart, packet.genhash, packet.rand, packet.filesize, hashhex);
if (!localfileid){
debug(D_WARNING, "got request for file that we do not have");
goto err0;
}
binpubrsa=psync_ssl_alloc_binary_rsa(packet.keylen);
if (unlikely_log(socket_read_all(sock, binpubrsa->data, binpubrsa->datalen))){
psync_free(binpubrsa);
goto err0;
}
token=psync_new_cnt(char, packet.tokenlen);
if (unlikely_log(socket_read_all(sock, token, packet.tokenlen)) ||
unlikely_log(!check_token(token, packet.tokenlen, binpubrsa->data, packet.keylen, hashhex))){
psync_free(binpubrsa);
psync_free(token);
goto err0;
}
psync_free(token);
pubrsa=psync_ssl_rsa_binary_to_public(binpubrsa);
psync_free(binpubrsa);
if (unlikely_log(pubrsa==PSYNC_INVALID_RSA))
goto err0;
localpath=psync_local_path_for_local_file(localfileid, NULL);
if (unlikely_log(!localpath))
goto err0;
fd=psync_file_open(localpath, P_O_RDONLY, 0);
debug(D_NOTICE, "sending file %s to peer", localpath);
psync_free(localpath);
if (fd==INVALID_HANDLE_VALUE){
debug(D_WARNING, "could not open local file %lu", (unsigned long)localfileid);
goto err0;
}
aeskey=psync_crypto_aes256_ctr_gen_key();
encaeskey=psync_ssl_rsa_encrypt_symmetric_key(pubrsa, aeskey);
encoder=psync_crypto_aes256_ctr_encoder_decoder_create(aeskey);
psync_ssl_free_symmetric_key(aeskey);
keylen=encaeskey->datalen;
enctype=P2P_ENCTYPE_RSA_AES;
if (unlikely_log(encaeskey==PSYNC_INVALID_ENC_SYM_KEY) || unlikely_log(encoder==PSYNC_CRYPTO_INVALID_ENCODER) ||
unlikely_log(socket_write_all(sock, &keylen, sizeof(keylen)) || socket_write_all(sock, &enctype, sizeof(enctype)) ||
socket_write_all(sock, encaeskey->data, encaeskey->datalen))){
if (encaeskey!=PSYNC_INVALID_ENC_SYM_KEY)
psync_free(encaeskey);
if (encoder!=PSYNC_CRYPTO_INVALID_ENCODER)
psync_crypto_aes256_ctr_encoder_decoder_free(encoder);
psync_file_close(fd);
goto err0;
}
psync_free(encaeskey);
off=0;
while (off<packet.filesize){
if (packet.filesize-off<sizeof(buff))
rd=packet.filesize-off;
else
rd=sizeof(buff);
if (unlikely_log(psync_file_read(fd, buff, rd)!=rd))
break;
psync_crypto_aes256_ctr_encode_decode_inplace(encoder, buff, rd, off);
if (unlikely_log(socket_write_all(sock, buff, rd)))
break;
off+=rd;
}
psync_crypto_aes256_ctr_encoder_decoder_free(encoder);
psync_file_close(fd);
debug(D_NOTICE, "file sent successfuly");
err0:
psync_close_socket(sock);
}
static void psync_p2p_thread(){
ssize_t ret;
char buff[2048];
/* struct sockaddr_in6 addr; */
struct sockaddr_in addr4;
psync_socket_t tcpsock, socks[2], *inconn;
socklen_t sl;
int sret;
psync_wait_statuses_array(requiredstatuses, ARRAY_SIZE(requiredstatuses));
tcpsock=INVALID_SOCKET;
/* udpsock=psync_create_socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
if (unlikely_log(udpsock==INVALID_SOCKET)){*/
udpsock=psync_create_socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (unlikely_log(udpsock==INVALID_SOCKET))
goto ex;
setsockopt(udpsock, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));
memset(&addr4, 0, sizeof(addr4));
addr4.sin_family=AF_INET;
addr4.sin_port =htons(PSYNC_P2P_PORT);
addr4.sin_addr.s_addr=INADDR_ANY;
if (unlikely_log(bind(udpsock, (struct sockaddr *)&addr4, sizeof(addr4))==SOCKET_ERROR))
goto ex;
/* }
else{
setsockopt(udpsock, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));
memset(&addr, 0, sizeof(addr));
addr.sin6_family=AF_INET6;
addr.sin6_port =htons(PSYNC_P2P_PORT);
addr.sin6_addr =in6addr_any;
if (unlikely_log(bind(udpsock, (struct sockaddr *)&addr, sizeof(addr))==SOCKET_ERROR))
goto ex;
}
tcpsock=psync_create_socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
if (unlikely_log(tcpsock==INVALID_SOCKET)){*/
tcpsock=psync_create_socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (unlikely_log(tcpsock==INVALID_SOCKET))
goto ex;
setsockopt(tcpsock, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));
memset(&addr4, 0, sizeof(addr4));
addr4.sin_family=AF_INET;
addr4.sin_port =htons(0);
addr4.sin_addr.s_addr=INADDR_ANY;
if (unlikely_log(bind(tcpsock, (struct sockaddr *)&addr4, sizeof(addr4))==SOCKET_ERROR))
goto ex;
sl=sizeof(addr4);
if (unlikely_log(getsockname(tcpsock, (struct sockaddr *)&addr4, &sl)==SOCKET_ERROR))
goto ex;
tcpport=ntohs(addr4.sin_port);
/* }
else{
setsockopt(tcpsock, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));
memset(&addr, 0, sizeof(addr));
addr.sin6_family=AF_INET6;
addr.sin6_port =htons(0);
addr.sin6_addr =in6addr_any;
if (unlikely_log(bind(tcpsock, (struct sockaddr *)&addr, sizeof(addr))==SOCKET_ERROR))
goto ex;
sl=sizeof(addr);
if (unlikely_log(getsockname(tcpsock, (struct sockaddr *)&addr, &sl)==SOCKET_ERROR))
goto ex;
tcpport=ntohs(addr.sin6_port);
}*/
if (unlikely_log(listen(tcpsock, 2)))
goto ex;
socks[0]=udpsock;
socks[1]=tcpsock;
while (psync_do_run){
if (unlikely(!psync_setting_get_bool(_PS(p2psync)))){
pthread_mutex_lock(&p2pmutex);
if (!psync_setting_get_bool(_PS(p2psync))){
running=0;
psync_close_socket(tcpsock);
psync_close_socket(udpsock);
pthread_mutex_unlock(&p2pmutex);
return;
}
pthread_mutex_unlock(&p2pmutex);
}
psync_wait_statuses_array(requiredstatuses, ARRAY_SIZE(requiredstatuses));
sret=psync_select_in(socks, 2, -1);
if (unlikely_log(sret==-1)){
psync_milisleep(1);
continue;
}
if (sret==0){
paddrlen=sizeof(paddr);
ret=recvfrom(udpsock, buff, sizeof(buff), 0, (struct sockaddr *)&paddr, &paddrlen);
if (likely_log(ret!=SOCKET_ERROR))
psync_p2p_process_packet(buff, ret);
else
psync_milisleep(1);
}
else if (sret==1){
inconn=psync_new(psync_socket_t);
*inconn=accept(tcpsock, NULL, NULL);
if (unlikely_log(*inconn==INVALID_SOCKET))
psync_free(inconn);
else
psync_run_thread1("p2p tcp", psync_p2p_tcphandler, inconn);
}
}
ex:
pthread_mutex_lock(&p2pmutex);
running=0;
psync_close_socket(tcpsock);
psync_close_socket(udpsock);
pthread_mutex_unlock(&p2pmutex);
}
static void psync_p2p_start(){
pthread_mutex_lock(&p2pmutex);
psync_run_thread("p2p", psync_p2p_thread);
running=1;
pthread_mutex_unlock(&p2pmutex);
}
static void psync_p2p_wake(){
psync_socket_t sock;
struct sockaddr_in addr;
packet_type_t pack;
sock=psync_create_socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (unlikely_log(sock==INVALID_SOCKET))
return;
memset(&addr, 0, sizeof(addr));
addr.sin_family=AF_INET;
addr.sin_port=htons(PSYNC_P2P_PORT);
addr.sin_addr.s_addr=htonl(0x7f000001UL);
pack=P2P_WAKE;
if (connect(sock, (struct sockaddr *)&addr, sizeof(addr))!=SOCKET_ERROR)
assertw(psync_write_socket(sock, &pack, sizeof(pack))==sizeof(pack));
psync_close_socket(sock);
}
void psync_p2p_init(){
unsigned char computerbin[PSYNC_HASH_DIGEST_LEN];
psync_ssl_rand_weak(computerbin, PSYNC_HASH_DIGEST_LEN);
psync_binhex(computername, computerbin, PSYNC_HASH_DIGEST_LEN);
psync_timer_exception_handler(psync_p2p_wake);
if (!psync_setting_get_bool(_PS(p2psync)))
return;
psync_p2p_start();
}
void psync_p2p_change(){
if (psync_setting_get_bool(_PS(p2psync)))
psync_p2p_start();
else
psync_p2p_wake();
}
static int psync_p2p_check_rsa(){
static pthread_mutex_t rsa_lock=PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_lock(&rsa_lock);
if (psync_rsa_private==PSYNC_INVALID_RSA){
psync_rsa_t rsa;
psync_rsa_privatekey_t rsapriv;
psync_rsa_publickey_t rsapub;
psync_binary_rsa_key_t rsapubbin;
debug(D_NOTICE, "generating %ubit RSA key", PSYNC_P2P_RSA_SIZE);
rsa=psync_ssl_gen_rsa(PSYNC_P2P_RSA_SIZE);
debug(D_NOTICE, "key generated");
if (unlikely_log(rsa==PSYNC_INVALID_RSA))
goto rete;
rsapriv=psync_ssl_rsa_get_private(rsa);
rsapub=psync_ssl_rsa_get_public(rsa);
if (likely_log(rsapub!=PSYNC_INVALID_RSA))
rsapubbin=psync_ssl_rsa_public_to_binary(rsapub);
else
rsapubbin=PSYNC_INVALID_BIN_RSA;
psync_ssl_free_rsa(rsa);
if (likely_log(rsapriv!=PSYNC_INVALID_RSA && rsapub!=PSYNC_INVALID_RSA && rsapubbin!=PSYNC_INVALID_BIN_RSA)){
psync_rsa_private=rsapriv;
psync_rsa_public=rsapub;
psync_rsa_public_bin=rsapubbin;
goto ret0;
}
else{
if (rsapriv!=PSYNC_INVALID_RSA)
psync_ssl_rsa_free_private(rsapriv);
if (rsapub!=PSYNC_INVALID_RSA)
psync_ssl_rsa_free_public(rsapub);
if (rsapubbin!=PSYNC_INVALID_BIN_RSA)
psync_ssl_rsa_free_binary(rsapubbin);
goto rete;
}
}
ret0:
pthread_mutex_unlock(&rsa_lock);
return 0;
rete:
pthread_mutex_unlock(&rsa_lock);
return -1;
}
static int psync_p2p_get_download_token(psync_fileid_t fileid, const unsigned char *filehashhex, uint64_t fsize, unsigned char **token, size_t *tlen){
binparam params[]={P_STR("auth", psync_my_auth), P_NUM("fileid", fileid), P_NUM("filesize", fsize),
P_LSTR(PSYNC_CHECKSUM, filehashhex, PSYNC_HASH_DIGEST_HEXLEN),
P_LSTR("keydata", psync_rsa_public_bin->data, psync_rsa_public_bin->datalen)};
psync_socket *api;
binresult *res;
const binresult *ctoken;
*token=NULL; /* especially for gcc */
*tlen=0;
api=psync_apipool_get();
if (unlikely_log(!api))
return PSYNC_NET_TEMPFAIL;
res=send_command(api, "getfileownershiptoken", params);
if (unlikely_log(!res)){
psync_apipool_release_bad(api);
return PSYNC_NET_TEMPFAIL;
}
psync_apipool_release(api);
if (unlikely_log(psync_find_result(res, "result", PARAM_NUM)->num!=0)){
psync_free(res);
return PSYNC_NET_PERMFAIL;
}
ctoken=psync_find_result(res, "token", PARAM_STR);
*token=psync_malloc(ctoken->length+1);
memcpy(*token, ctoken->str, ctoken->length+1);
*tlen=ctoken->length;
psync_free(res);
return PSYNC_NET_OK;
}
static int psync_p2p_download(psync_socket_t sock, psync_fileid_t fileid, const unsigned char *filehashhex, uint64_t fsize, const char *filename){
uint32_t keylen, enctype;
psync_symmetric_key_t key;
psync_encrypted_symmetric_key_t ekey;
psync_crypto_aes256_ctr_encoder_decoder_t decoder;
psync_hash_ctx hashctx;
uint64_t off;
size_t rd;
psync_file_t fd;
unsigned char buff[4096];
unsigned char hashbin[PSYNC_HASH_DIGEST_LEN], hashhex[PSYNC_HASH_DIGEST_HEXLEN];
if (unlikely_log(socket_read_all(sock, &keylen, sizeof(keylen)) || socket_read_all(sock, &enctype, sizeof(enctype))))
return PSYNC_NET_TEMPFAIL;
if (enctype!=P2P_ENCTYPE_RSA_AES){
debug(D_ERROR, "unknown encryption type %u", (unsigned)enctype);
return PSYNC_NET_PERMFAIL;
}
if (keylen>PSYNC_P2P_RSA_SIZE/8*2){ /* PSYNC_P2P_RSA_SIZE/8 is enough actually */
debug(D_ERROR, "too long key - %u bytes", (unsigned)keylen);
return PSYNC_NET_PERMFAIL;
}
ekey=psync_ssl_alloc_encrypted_symmetric_key(keylen);
if (unlikely_log(socket_read_all(sock, ekey->data, keylen)) ||
unlikely_log((key = psync_ssl_rsa_decrypt_symm_key_lock(&psync_rsa_private, &ekey)) == PSYNC_INVALID_SYM_KEY)) {
//unlikely_log((key=psync_ssl_rsa_decrypt_symmetric_key(&psync_rsa_private, &ekey))==PSYNC_INVALID_SYM_KEY)){
psync_free(ekey);
return PSYNC_NET_TEMPFAIL;
}
psync_free(ekey);
decoder=psync_crypto_aes256_ctr_encoder_decoder_create(key);
psync_ssl_free_symmetric_key(key);
if (decoder==PSYNC_CRYPTO_INVALID_ENCODER)
return PSYNC_NET_PERMFAIL;
fd=psync_file_open(filename, P_O_WRONLY, P_O_CREAT|P_O_TRUNC);
if (unlikely(fd==INVALID_HANDLE_VALUE)){
psync_crypto_aes256_ctr_encoder_decoder_free(decoder);
debug(D_ERROR, "could not open %s", filename);
return PSYNC_NET_PERMFAIL;
}
off=0;
psync_hash_init(&hashctx);
while (off<fsize){
if (fsize-off>sizeof(buff))
rd=sizeof(buff);
else
rd=fsize-off;
if (unlikely_log(socket_read_all(sock, buff, rd)))
goto err0;
psync_crypto_aes256_ctr_encode_decode_inplace(decoder, buff, rd, off);
if (unlikely_log(psync_file_write(fd, buff, rd)!=rd))
goto err0;
psync_hash_update(&hashctx, buff, rd);
off+=rd;
}
psync_crypto_aes256_ctr_encoder_decoder_free(decoder);
psync_file_close(fd);
psync_hash_final(hashbin, &hashctx);
psync_binhex(hashhex, hashbin, PSYNC_HASH_DIGEST_LEN);
debug(D_NOTICE, "downloaded file %s from peer", filename);
if (memcmp(hashhex, filehashhex, PSYNC_HASH_DIGEST_HEXLEN)){
/* it is better to return permanent fail and let the block checksum algo to find bad blocks */
debug(D_WARNING, "got bad checksum for file %s", filename);
return PSYNC_NET_PERMFAIL;
}
else
return PSYNC_NET_OK;
err0:
psync_crypto_aes256_ctr_encoder_decoder_free(decoder);
psync_file_close(fd);
psync_hash_final(hashbin, &hashctx);
return PSYNC_NET_TEMPFAIL;
}
int psync_p2p_check_download(psync_fileid_t fileid, const unsigned char *filehashhex, uint64_t fsize, const char *filename){
struct sockaddr_in6 addr;
fd_set rfds;
packet_check pct1;
packet_get pct2;
packet_check_resp resp;
struct timeval tv;
psync_interface_list_t *il;
psync_socket_t *sockets;
size_t i, tlen;
psync_socket_t sock, msock;
packet_resp_t bresp;
unsigned char hashsource[PSYNC_HASH_BLOCK_SIZE], hashbin[PSYNC_HASH_DIGEST_LEN], hashhex[PSYNC_HASH_DIGEST_HEXLEN];
unsigned char *token;
socklen_t slen;
int sret;
if (!psync_setting_get_bool(_PS(p2psync)))
return PSYNC_NET_PERMFAIL;
debug(D_NOTICE, "sending P2P_CHECK for file with hash %."NTO_STR(PSYNC_HASH_DIGEST_HEXLEN)"s", filehashhex);
pct1.type=P2P_CHECK;
memcpy(pct1.hashstart, filehashhex, PSYNC_P2P_HEXHASH_BYTES);
pct1.filesize=fsize;
psync_ssl_rand_weak(pct1.rand, sizeof(pct1.rand));
memcpy(hashsource, filehashhex, PSYNC_HASH_DIGEST_HEXLEN);
memcpy(hashsource+PSYNC_HASH_DIGEST_HEXLEN, pct1.rand, sizeof(pct1.rand));
psync_hash(hashsource, PSYNC_HASH_BLOCK_SIZE, hashbin);
psync_binhex(pct1.genhash, hashbin, PSYNC_HASH_DIGEST_LEN);
memcpy(pct1.computername, computername, PSYNC_HASH_DIGEST_HEXLEN);
il=psync_list_ip_adapters();
sockets=psync_new_cnt(psync_socket_t, il->interfacecnt);
FD_ZERO(&rfds);
msock=0;
for (i=0; i<il->interfacecnt; i++){
sockets[i]=INVALID_SOCKET;
sock=psync_create_socket(il->interfaces[i].address.ss_family, SOCK_DGRAM, IPPROTO_UDP);
if (unlikely(sock==INVALID_SOCKET)){
debug(D_NOTICE, "could not create a socket for address family %u", (unsigned)il->interfaces[i].address.ss_family);
continue;
}
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));
setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (const char *)&on, sizeof(on));
if (unlikely_log(bind(sock, (struct sockaddr *)&il->interfaces[i].address, il->interfaces[i].addrsize)==SOCKET_ERROR)){
psync_close_socket(sock);
continue;
}
if (il->interfaces[i].broadcast.ss_family==AF_INET)
((struct sockaddr_in *)(&il->interfaces[i].broadcast))->sin_port=htons(PSYNC_P2P_PORT);
else if (il->interfaces[i].broadcast.ss_family==AF_INET6)
((struct sockaddr_in6 *)(&il->interfaces[i].broadcast))->sin6_port=htons(PSYNC_P2P_PORT);
if (sendto(sock, (const char *)&pct1, sizeof(pct1), 0, (struct sockaddr *)&il->interfaces[i].broadcast, il->interfaces[i].addrsize)!=SOCKET_ERROR){
sockets[i]=sock;
FD_SET(sock, &rfds);
if (sock>=msock)
msock=sock+1;
}
else
psync_close_socket(sock);
}
if (unlikely_log(!msock))
goto err_perm;
tv.tv_sec=PSYNC_P2P_INITIAL_TIMEOUT/1000;
tv.tv_usec=(PSYNC_P2P_INITIAL_TIMEOUT%1000)*1000;
sret=select(msock, &rfds, NULL, NULL, &tv);
if (sret==0 || unlikely_log(sret==SOCKET_ERROR))
goto err_perm;
bresp=P2P_RESP_NOPE;
for (i=0; i<il->interfacecnt; i++)
if (sockets[i]!=INVALID_SOCKET && FD_ISSET(sockets[i], &rfds)){
slen=sizeof(addr);
sret=recvfrom(sockets[i], (char *)&resp, sizeof(resp), 0, (struct sockaddr *)&addr, &slen);
if (unlikely_log(sret==SOCKET_ERROR) || unlikely_log(sret<sizeof(resp)))
continue;
if (!memcmp(pct1.rand, resp.rand, sizeof(resp.rand))){
debug(D_WARNING, "clients are supposed to generate random data, not to reuse mine");
continue;
}
memcpy(hashsource, filehashhex, PSYNC_HASH_DIGEST_HEXLEN);
memcpy(hashsource+PSYNC_HASH_DIGEST_HEXLEN, resp.rand, sizeof(resp.rand));
psync_hash(hashsource, PSYNC_HASH_BLOCK_SIZE, hashbin);
psync_binhex(hashhex, hashbin, PSYNC_HASH_DIGEST_LEN);
if (unlikely_log(memcmp(hashhex, resp.genhash, PSYNC_HASH_DIGEST_HEXLEN)))
continue;
if (resp.type==P2P_RESP_HAVEIT){
debug(D_NOTICE, "got P2P_RESP_HAVEIT");
bresp=P2P_RESP_HAVEIT;
break;
}
else if (resp.type==P2P_RESP_WAIT && bresp==P2P_RESP_NOPE)
bresp=P2P_RESP_WAIT;
}
for (i=0; i<il->interfacecnt; i++)
if (sockets[i]!=INVALID_SOCKET)
psync_close_socket(sockets[i]);
psync_free(il);
psync_free(sockets);
if (bresp==P2P_RESP_NOPE)
goto err_perm2;
else if (bresp==P2P_RESP_WAIT){
uint32_t rnd;
psync_ssl_rand_weak((unsigned char *)&rnd, sizeof(rnd));
rnd&=0x7ff;
psync_milisleep(PSYNC_P2P_SLEEP_WAIT_DOWNLOAD+rnd);
goto err_temp2;
}
if (psync_p2p_check_rsa())
goto err_perm2;
sret=psync_p2p_get_download_token(fileid, filehashhex, fsize, &token, &tlen);
debug(D_NOTICE, "got token");
if (unlikely_log(sret!=PSYNC_NET_OK)){
if (sret==PSYNC_NET_TEMPFAIL)
goto err_temp2;
else
goto err_perm2;
}
if (addr.sin6_family==AF_INET6){
sock=psync_create_socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
addr.sin6_port=htons(resp.port);
}
else if (addr.sin6_family==AF_INET){
sock=psync_create_socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
((struct sockaddr_in *)&addr)->sin_port=htons(resp.port);
}
else{
debug(D_ERROR, "unknown address family %u", (unsigned)addr.sin6_family);
goto err_perm2;
}
if (unlikely_log(sock==INVALID_SOCKET))
goto err_perm3;
if (unlikely(connect(sock, (struct sockaddr *)&addr, slen)==SOCKET_ERROR)){
debug(D_WARNING, "could not connect to %s port %u", p2p_get_address(&addr), (unsigned)resp.port);
goto err_perm3;
}
debug(D_NOTICE, "connected to peer");
pct2.type=P2P_GET;
memcpy(pct2.hashstart, filehashhex, PSYNC_P2P_HEXHASH_BYTES);
pct2.filesize=fsize;
pct2.keylen=psync_rsa_public_bin->datalen;
pct2.tokenlen=tlen;
memcpy(pct2.rand, pct1.rand, sizeof(pct1.rand));
memcpy(pct2.genhash, pct1.genhash, sizeof(pct1.genhash));
memcpy(pct2.computername, computername, PSYNC_HASH_DIGEST_HEXLEN);
if (socket_write_all(sock, &pct2, sizeof(pct2)) ||
socket_write_all(sock, psync_rsa_public_bin->data, psync_rsa_public_bin->datalen) ||
socket_write_all(sock, token, tlen)){
debug(D_WARNING, "writing to socket failed");
goto err_temp3;
}
psync_free(token);
sret=psync_p2p_download(sock, fileid, filehashhex, fsize, filename);
psync_close_socket(sock);
return sret;
err_perm3:
psync_free(token);
goto err_perm2;
err_perm:
for (i=0; i<il->interfacecnt; i++)
if (sockets[i]!=INVALID_SOCKET)
psync_close_socket(sockets[i]);
psync_free(il);
psync_free(sockets);
err_perm2:
return PSYNC_NET_PERMFAIL;
err_temp3:
psync_close_socket(sock);
psync_free(token);
err_temp2:
return PSYNC_NET_TEMPFAIL;
}
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