void echo_stream()
{
int acceptor, sock;
if (signal(SIGCHLD, reaper) == SIG_ERR) {
die(-1, "unable to catch SIGCHLD");
}
say("Stream service started\n");
/* Prepare XSSL context and get SID (based on RSA key) */
XSSL_CTX *ctx = XSSL_CTX_new();
if (ctx == NULL) {
die(-5, "Unable to create new XSSL_CTX\n");
}
char *SID = SID_from_keypair(ctx->keypair);
/* Prepare listen socket, binding to generated SID */
if ((acceptor = Xsocket(AF_XIA, SOCK_STREAM, 0)) < 0)
die(-2, "unable to create the stream socket\n");
struct addrinfo *ai;
if (Xgetaddrinfo(NULL, SID, NULL, &ai) != 0)
die(-1, "getaddrinfo failure!\n");
Graph g((sockaddr_x*)ai->ai_addr);
sockaddr_x *sa = (sockaddr_x*)ai->ai_addr;
printf("\nStream DAG\n%s\n", g.dag_string().c_str());
if (XregisterName(STREAM_NAME, sa) < 0 )
die(-1, "error registering name: %s\n", STREAM_NAME);
say("registered name: \n%s\n", STREAM_NAME);
if (Xbind(acceptor, (struct sockaddr *)sa, sizeof(sockaddr_x)) < 0) {
die(-3, "unable to bind to the dag\n");
}
Xlisten(acceptor, 5);
while (1) {
say("Xsock %4d waiting for a new connection.\n", acceptor);
if ((sock = Xaccept(acceptor, NULL, 0)) < 0) {
warn("Xsock %d accept failure! error = %d\n", acceptor, errno);
// FIXME: should we die here instead or try and recover?
continue;
}
say ("Xsock %4d new session\n", sock);
pid_t pid = fork();
if (pid == -1) {
die(-1, "FORK FAILED\n");
} else if (pid == 0) {
process(sock, ctx);
exit(0);
} else {
// FIXME: we need to close the socket in the main process or the file
// descriptor limit will be hit. But if Xclose is called, the connection
// is torn down in click as well keeping the child process from using it.
// for now use a regular close to shut it here without affecting the child.
close(sock);
}
}
Xclose(acceptor);
XSSL_CTX_free(ctx);
free(SID);
}
/**
* @brief Initiate an XSSL connection with server.
*
* @param xssl
*
* @return 1 on success, <1 on failure
*/
int XSSL_connect(XSSL *xssl) {
char buf[XIA_MAXBUF];
int n;
/* Send CLIENT HELLO */
sprintf(buf, "CLIENT HELLO");
if ((n = Xsend(xssl->sockfd, buf, strlen(buf), 0)) != strlen(buf)) {
ERROR("ERROR sending CLIENT HELLO");
return 0;
}
/* Wait for SERVER HELLO */
// Receive public key + temporary public key signed by server's long-term private key
// Continue receiving until we see "SERVER DONE"
int offset = 0;
while ( offset < 11 || strcmp("SERVER DONE", &buf[offset-11]) != 0 ) {
n = Xrecv(xssl->sockfd, &buf[offset], sizeof(buf)-offset, 0);
if (n < 0) {
ERROR("ERROR receiving SERVER HELLO");
return n;
}
if (n == 0) {
ERROR("ERROR: server closed connection during SERVER HELLO");
return n;
}
offset += n;
}
/* Parse public keys from SERVER HELLO */
offset = strlen("SERVER HELLO");
char *keys = &buf[offset]; // start of signed portion of message
uint32_t *keybufsizeptr = (uint32_t*)&buf[offset];
uint32_t keybufsize = *keybufsizeptr; // TODO: error checking here
offset += sizeof(uint32_t);
RSA *pubkey = deserialize_rsa_pub_key(&buf[offset], keybufsize);
offset += keybufsize;
uint32_t *tempkeybufsizeptr = (uint32_t*)&buf[offset];
uint32_t tempkeybufsize = *tempkeybufsizeptr;
offset += sizeof(uint32_t);
RSA *sessionPubkey = deserialize_rsa_pub_key(&buf[offset], tempkeybufsize);
offset += tempkeybufsize;
uint32_t *siglenptr = (uint32_t*)&buf[offset];
uint32_t siglen = *siglenptr;
offset += sizeof(uint32_t);
char* sig = &buf[offset];
offset += siglen;
DBGF("Received keys:\n\tkeylen: %d\n\ttempkeylen: %d\n\tsiglen: %d", keybufsize, tempkeybufsize, siglen);
/* Verify two things:
* 1) hash(key) == SID so we trust the signature
* 2) verify the sig so we trust the temp key
*/
sockaddr_x *sa = (sockaddr_x*)malloc(sizeof(sockaddr_x));
socklen_t len = sizeof(sockaddr_x);
if (Xgetpeername(xssl->sockfd, (struct sockaddr*)sa, &len) < 0) {
ERRORF("Error in Xgetpeername on socket %d: %s", xssl->sockfd, strerror(errno));
return 0;
}
Graph g(sa);
Node sid_node = g.get_final_intent();
DBGF("SID: %s", sid_node.to_string().c_str());
char *sid_from_key_hash = SID_from_keypair(pubkey);
DBGF("Pub key hash: %s", sid_from_key_hash);
if (strcmp(sid_node.to_string().c_str(), sid_from_key_hash) != 0) {
WARN("Hash of received public key does not match SID! Closing connection.");
return 0;
}
if (verify(pubkey, keys, keybufsize+tempkeybufsize+2*sizeof(uint32_t), sig, siglen) != 1) {
WARN("Unable to verify signature on temporary RSA keypair! Closing connection.");
return 0;
}
/* Generate pre-master secret and send to server, encrypted with sessionPubKey */
unsigned char* pms = (unsigned char*)malloc(PRE_MASTER_SECRET_LENGTH);
if (RAND_bytes(pms, PRE_MASTER_SECRET_LENGTH) != 1) {
ERROR("ERROR: Couldn't generate pre-master secret");
return 0;
}
if (VERBOSITY >= V_DEBUG) {
DBG("Pre-Master Secret:");
print_bytes(pms, PRE_MASTER_SECRET_LENGTH);
}
int ciphertext_len;
if ( (ciphertext_len = pub_encrypt(sessionPubkey,
pms, PRE_MASTER_SECRET_LENGTH,
buf, XIA_MAXBUF)) == -1 ) {
ERROR("ERROR: Unable to encrypt session key");
return 0;
}
n = 0;
offset = 0;
while (offset < ciphertext_len) {
if ((n = Xsend(xssl->sockfd, &buf[offset], ciphertext_len-offset, 0)) < 0) {
ERROR("ERROR sending pre-master secret");
return 0;
}
offset += n;
}
/* Init symmetric session ciphers with pre-master secret.
Client encrypt context initialized with same key data as
server decrypt context and vice versa. */
uint32_t salt[] = SALT;
if (aes_init(pms, PRE_MASTER_SECRET_LENGTH/2,
&pms[PRE_MASTER_SECRET_LENGTH/2], PRE_MASTER_SECRET_LENGTH/2,
(unsigned char *)&salt, xssl->en, xssl->de)) {
ERROR("ERROR initializing AES ciphers");
return 0;
}
free(pms);
/* For now, omitting CLIENT DONE */
return 1;
}
