libfreerdp-crypto: fix OpenSSL workarounds on client and server

diff --git a/libfreerdp-crypto/tls.c b/libfreerdp-crypto/tls.c
index beba56b..1bd2f9a 100644 (file)
--- a/libfreerdp-crypto/tls.c
+++ b/libfreerdp-crypto/tls.c
@@ -56,6 +56,7 @@ static void tls_free_certificate(CryptoCert cert)
 boolean tls_connect(rdpTls* tls)
 {
        CryptoCert cert;
+       long options = 0;
        int connection_status;
 
        tls->ctx = SSL_CTX_new(TLSv1_client_method());
@@ -66,15 +67,34 @@ boolean tls_connect(rdpTls* tls)
                return false;
        }
 
-       /*
-        * This is necessary, because the Microsoft TLS implementation is not perfect.
-        * SSL_OP_ALL enables a couple of workarounds for buggy TLS implementations,
-        * but the most important workaround being SSL_OP_TLS_BLOCK_PADDING_BUG.
-        * As the size of the encrypted payload may give hints about its contents,
-        * block padding is normally used, but the Microsoft TLS implementation
-        * won't recognize it and will disconnect you after sending a TLS alert.
+       /**
+        * 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.
+        */
+       options |= SSL_OP_NO_COMPRESSION;
+
+       /**
+        * 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.
         */
-       SSL_CTX_set_options(tls->ctx, SSL_OP_ALL);
+       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);
 
@@ -131,6 +151,7 @@ boolean tls_connect(rdpTls* tls)
 boolean tls_accept(rdpTls* tls, const char* cert_file, const char* privatekey_file)
 {
        CryptoCert cert;
+       long options = 0;
        int connection_status;
 
        tls->ctx = SSL_CTX_new(SSLv23_server_method());
@@ -142,10 +163,41 @@ boolean tls_accept(rdpTls* tls, const char* cert_file, const char* privatekey_fi
        }
 
        /*
+        * SSL_OP_NO_SSLv2:
+        *
         * We only want SSLv3 and TLSv1, so disable SSLv2.
         * SSLv3 is used by, eg. Microsoft RDC for Mac OS X.
         */
-       SSL_CTX_set_options(tls->ctx, SSL_OP_NO_SSLv2);
+       options |= SSL_OP_NO_SSLv2;
+
+       /**
+        * 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.
+        */
+       options |= SSL_OP_NO_COMPRESSION;
+
+       /**
+        * 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);
 
        if (SSL_CTX_use_RSAPrivateKey_file(tls->ctx, privatekey_file, SSL_FILETYPE_PEM) <= 0)
        {

diff --git a/server/X11/xf_peer.c b/server/X11/xf_peer.c
index 1689ac8..0fdb717 100644 (file)
--- a/server/X11/xf_peer.c
+++ b/server/X11/xf_peer.c
@@ -634,6 +634,8 @@ void* xf_peer_main_loop(void* arg)
        settings->privatekey_file = freerdp_construct_path(server_file_path, "server.key");
 
        settings->nla_security = true;
+       settings->tls_security = false;
+       settings->rdp_security = false;
 
        settings->rfx_codec = true;