BOOL tls_connect(rdpTls* tls)
{
CryptoCert cert;
long options = 0;
int connection_status;
char *hostname;
tls->ctx = SSL_CTX_new(TLSv1_client_method());
if (tls->ctx == NULL)
{
fprintf(stderr, "SSL_CTX_new failed\n");
return FALSE;
}
//SSL_CTX_set_mode(tls->ctx, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER | SSL_MODE_ENABLE_PARTIAL_WRITE);
/**
* SSL_OP_NO_COMPRESSION:
*
* The Microsoft RDP server does not advertise support
* for TLS compression, but alternative servers may support it.
* This was observed between early versions of the FreeRDP server
* and the FreeRDP client, and caused major performance issues,
* which is why we're disabling it.
*/
#ifdef SSL_OP_NO_COMPRESSION
options |= SSL_OP_NO_COMPRESSION;
#endif
/**
* SSL_OP_TLS_BLOCK_PADDING_BUG:
*
* The Microsoft RDP server does *not* support TLS padding.
* It absolutely needs to be disabled otherwise it won't work.
*/
options |= SSL_OP_TLS_BLOCK_PADDING_BUG;
/**
* SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS:
*
* Just like TLS padding, the Microsoft RDP server does not
* support empty fragments. This needs to be disabled.
*/
options |= SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS;
SSL_CTX_set_options(tls->ctx, options);
tls->ssl = SSL_new(tls->ctx);
if (tls->ssl == NULL)
{
fprintf(stderr, "SSL_new failed\n");
return FALSE;
}
if (SSL_set_fd(tls->ssl, tls->sockfd) < 1)
{
fprintf(stderr, "SSL_set_fd failed\n");
return FALSE;
}
connection_status = SSL_connect(tls->ssl);
if (connection_status <= 0)
{
if (tls_print_error("SSL_connect", tls->ssl, connection_status))
{
return FALSE;
}
}
cert = tls_get_certificate(tls, TRUE);
if (cert == NULL)
{
fprintf(stderr, "tls_connect: tls_get_certificate failed to return the server certificate.\n");
return FALSE;
}
tls->Bindings = tls_get_channel_bindings(cert->px509);
if (!crypto_cert_get_public_key(cert, &tls->PublicKey, &tls->PublicKeyLength))
{
fprintf(stderr, "tls_connect: crypto_cert_get_public_key failed to return the server public key.\n");
tls_free_certificate(cert);
return FALSE;
}
if (tls->settings->GatewayUsageMethod)
hostname = tls->settings->GatewayHostname;
else
hostname = tls->settings->ServerHostname;
if (!tls_verify_certificate(tls, cert, hostname))
{
fprintf(stderr, "tls_connect: certificate not trusted, aborting.\n");
tls_disconnect(tls);
tls_free_certificate(cert);
return FALSE;
}
tls_free_certificate(cert);
return TRUE;
}
int tls_do_handshake(rdpTls* tls, BOOL clientMode)
{
CryptoCert cert;
int verify_status;
do
{
#ifdef HAVE_POLL_H
int fd;
int status;
struct pollfd pollfds;
#elif !defined(_WIN32)
int fd;
int status;
fd_set rset;
struct timeval tv;
#else
HANDLE event;
DWORD status;
#endif
status = BIO_do_handshake(tls->bio);
if (status == 1)
break;
if (!BIO_should_retry(tls->bio))
return -1;
#ifndef _WIN32
/* we select() only for read even if we should test both read and write
* depending of what have blocked */
fd = BIO_get_fd(tls->bio, NULL);
if (fd < 0)
{
WLog_ERR(TAG, "unable to retrieve BIO fd");
return -1;
}
#else
BIO_get_event(tls->bio, &event);
if (!event)
{
WLog_ERR(TAG, "unable to retrieve BIO event");
return -1;
}
#endif
#ifdef HAVE_POLL_H
pollfds.fd = fd;
pollfds.events = POLLIN;
pollfds.revents = 0;
do
{
status = poll(&pollfds, 1, 10 * 1000);
}
while ((status < 0) && (errno == EINTR));
#elif !defined(_WIN32)
FD_ZERO(&rset);
FD_SET(fd, &rset);
tv.tv_sec = 0;
tv.tv_usec = 10 * 1000; /* 10ms */
status = _select(fd + 1, &rset, NULL, NULL, &tv);
#else
status = WaitForSingleObject(event, 10);
#endif
#ifndef _WIN32
if (status < 0)
{
WLog_ERR(TAG, "error during select()");
return -1;
}
#else
if ((status != WAIT_OBJECT_0) && (status != WAIT_TIMEOUT))
{
WLog_ERR(TAG, "error during WaitForSingleObject(): 0x%04X", status);
return -1;
}
#endif
}
while (TRUE);
cert = tls_get_certificate(tls, clientMode);
if (!cert)
{
WLog_ERR(TAG, "tls_get_certificate failed to return the server certificate.");
return -1;
}
tls->Bindings = tls_get_channel_bindings(cert->px509);
if (!tls->Bindings)
{
WLog_ERR(TAG, "unable to retrieve bindings");
verify_status = -1;
goto out;
}
if (!crypto_cert_get_public_key(cert, &tls->PublicKey, &tls->PublicKeyLength))
{
WLog_ERR(TAG,
"crypto_cert_get_public_key failed to return the server public key.");
verify_status = -1;
goto out;
}
/* server-side NLA needs public keys (keys from us, the server) but no certificate verify */
verify_status = 1;
if (clientMode)
{
verify_status = tls_verify_certificate(tls, cert, tls->hostname, tls->port);
if (verify_status < 1)
{
WLog_ERR(TAG, "certificate not trusted, aborting.");
tls_send_alert(tls);
verify_status = 0;
}
}
out:
tls_free_certificate(cert);
return verify_status;
}
int tls_do_handshake(rdpTls* tls, BOOL clientMode)
{
CryptoCert cert;
int verify_status, status;
do
{
#ifdef HAVE_POLL_H
struct pollfd pollfds;
#else
struct timeval tv;
fd_set rset;
#endif
int fd;
status = BIO_do_handshake(tls->bio);
if (status == 1)
break;
if (!BIO_should_retry(tls->bio))
return -1;
/* we select() only for read even if we should test both read and write
* depending of what have blocked */
fd = BIO_get_fd(tls->bio, NULL);
if (fd < 0)
{
DEBUG_WARN( "%s: unable to retrieve BIO fd\n", __FUNCTION__);
return -1;
}
#ifdef HAVE_POLL_H
pollfds.fd = fd;
pollfds.events = POLLIN;
pollfds.revents = 0;
do
{
status = poll(&pollfds, 1, 10 * 1000);
}
while ((status < 0) && (errno == EINTR));
#else
FD_ZERO(&rset);
FD_SET(fd, &rset);
tv.tv_sec = 0;
tv.tv_usec = 10 * 1000; /* 10ms */
status = _select(fd + 1, &rset, NULL, NULL, &tv);
#endif
if (status < 0)
{
DEBUG_WARN( "%s: error during select()\n", __FUNCTION__);
return -1;
}
}
while (TRUE);
cert = tls_get_certificate(tls, clientMode);
if (!cert)
{
DEBUG_WARN( "%s: tls_get_certificate failed to return the server certificate.\n", __FUNCTION__);
return -1;
}
tls->Bindings = tls_get_channel_bindings(cert->px509);
if (!tls->Bindings)
{
DEBUG_WARN( "%s: unable to retrieve bindings\n", __FUNCTION__);
verify_status = -1;
goto out;
}
if (!crypto_cert_get_public_key(cert, &tls->PublicKey, &tls->PublicKeyLength))
{
DEBUG_WARN( "%s: crypto_cert_get_public_key failed to return the server public key.\n", __FUNCTION__);
verify_status = -1;
goto out;
}
/* Note: server-side NLA needs public keys (keys from us, the server) but no
* certificate verify
*/
verify_status = 1;
if (clientMode)
{
verify_status = tls_verify_certificate(tls, cert, tls->hostname, tls->port);
if (verify_status < 1)
{
DEBUG_WARN( "%s: certificate not trusted, aborting.\n", __FUNCTION__);
tls_disconnect(tls);
verify_status = 0;
}
}
out:
tls_free_certificate(cert);
return verify_status;
}
