share SCHANNEL_CRED

Share `SCHANNEL_CRED` on all client/pool connections. This is intended to simplify future fix for CDRIVER-5998. As an added benefit, this reduces the repeated reading of PEM files for each connection.

Author: kevinAlbs

src/libmongoc/CMakeLists.txt

@@ -1075,6 +1075,7 @@ set (test-libmongoc-sources
    ${PROJECT_SOURCE_DIR}/tests/test-mongoc-scram.c
    ${PROJECT_SOURCE_DIR}/tests/test-mongoc-sdam-monitoring.c
    ${PROJECT_SOURCE_DIR}/tests/test-mongoc-sdam.c
+   ${PROJECT_SOURCE_DIR}/tests/test-mongoc-secure-channel.c
    ${PROJECT_SOURCE_DIR}/tests/test-mongoc-server-description.c
    ${PROJECT_SOURCE_DIR}/tests/test-mongoc-server-selection-errors.c
    ${PROJECT_SOURCE_DIR}/tests/test-mongoc-server-selection.c

src/libmongoc/src/mongoc/mongoc-client-pool.c

@@ -39,6 +39,10 @@
 #include <mongoc/mongoc-openssl-private.h>
 #endif
 
+#if defined(MONGOC_ENABLE_SSL_SECURE_CHANNEL)
+#include <mongoc/mongoc-stream-tls-secure-channel-private.h>
+#endif
+
 struct _mongoc_client_pool_t {
    bson_mutex_t mutex;
    mongoc_cond_t cond;
@@ -84,6 +88,15 @@ mongoc_client_pool_set_ssl_opts (mongoc_client_pool_t *pool, const mongoc_ssl_op
       SSL_CTX_free (pool->topology->scanner->openssl_ctx);
       pool->topology->scanner->openssl_ctx = _mongoc_openssl_ctx_new (&pool->ssl_opts);
 #endif
+
+#if defined(MONGOC_ENABLE_SSL_SECURE_CHANNEL)
+      // Access to secure_channel_cred_ptr does not need the thread-safe `mongoc_atomic_*` functions.
+      // secure_channel_cred_ptr is not expected to be modified by multiple threads.
+      // mongoc_client_pool_set_ssl_opts documentation prohibits calling after threads start.
+      mongoc_shared_ptr_reset (&pool->topology->scanner->secure_channel_cred_ptr,
+                               mongoc_secure_channel_cred_new (&pool->ssl_opts),
+                               mongoc_secure_channel_cred_deleter);
+#endif
    }
 
    mongoc_topology_scanner_set_ssl_opts (pool->topology->scanner, &pool->ssl_opts);

src/libmongoc/src/mongoc/mongoc-client-private.h

@@ -38,6 +38,7 @@
 #include <mongoc/mongoc-topology-private.h>
 #include <mongoc/mongoc-write-concern.h>
 #include <mongoc/mongoc-crypt-private.h>
+#include <mongoc/mongoc-shared-private.h>
 
 BSON_BEGIN_DECLS
 
@@ -212,6 +213,7 @@ mongoc_client_connect (bool buffered,
                        const mongoc_uri_t *uri,
                        const mongoc_host_list_t *host,
                        void *openssl_ctx_void,
+                       mongoc_shared_ptr secure_channel_cred_ptr,
                        bson_error_t *error);
 
 

src/libmongoc/src/mongoc/mongoc-client.c

@@ -70,6 +70,11 @@
 #include <mongoc/mongoc-stream-tls-private.h>
 #endif
 
+#if defined(MONGOC_ENABLE_SSL_SECURE_CHANNEL)
+#include <mongoc/mongoc-stream-tls-secure-channel-private.h>
+#include <mongoc/mongoc-stream-tls-private.h>
+#endif
+
 #include <common-string-private.h>
 #include <mlib/cmp.h>
 
@@ -756,6 +761,7 @@ mongoc_client_connect (bool buffered,
                        const mongoc_uri_t *uri,
                        const mongoc_host_list_t *host,
                        void *openssl_ctx_void,
+                       mongoc_shared_ptr secure_channel_cred_ptr,
                        bson_error_t *error)
 {
    mongoc_stream_t *base_stream = NULL;
@@ -765,6 +771,7 @@ mongoc_client_connect (bool buffered,
    BSON_ASSERT (host);
 
    BSON_UNUSED (openssl_ctx_void);
+   BSON_UNUSED (secure_channel_cred_ptr);
 
 #ifndef MONGOC_ENABLE_SSL
    if (ssl_opts_void || mongoc_uri_get_tls (uri)) {
@@ -814,6 +821,9 @@ mongoc_client_connect (bool buffered,
          // Use shared OpenSSL context.
          base_stream = mongoc_stream_tls_new_with_hostname_and_openssl_context (
             base_stream, host->host, ssl_opts, true, (SSL_CTX *) openssl_ctx_void);
+#elif defined(MONGOC_ENABLE_SSL_SECURE_CHANNEL)
+         // Use shared Secure Channel credentials.
+         base_stream = mongoc_stream_tls_new_with_secure_channel_cred (base_stream, ssl_opts, secure_channel_cred_ptr);
 #else
          base_stream = mongoc_stream_tls_new_with_hostname (base_stream, host->host, ssl_opts, true);
 #endif
@@ -881,9 +891,13 @@ mongoc_client_default_stream_initiator (const mongoc_uri_t *uri,
 
 #if defined(MONGOC_ENABLE_SSL_OPENSSL) && OPENSSL_VERSION_NUMBER >= 0x10100000L
    SSL_CTX *ssl_ctx = client->topology->scanner->openssl_ctx;
-   return mongoc_client_connect (true, use_ssl, ssl_opts_void, uri, host, (void *) ssl_ctx, error);
+   return mongoc_client_connect (
+      true, use_ssl, ssl_opts_void, uri, host, (void *) ssl_ctx, MONGOC_SHARED_PTR_NULL, error);
+#elif defined(MONGOC_ENABLE_SSL_SECURE_CHANNEL)
+   mongoc_shared_ptr cred_ptr = client->topology->scanner->secure_channel_cred_ptr;
+   return mongoc_client_connect (true, use_ssl, ssl_opts_void, uri, host, NULL, cred_ptr, error);
 #else
-   return mongoc_client_connect (true, use_ssl, ssl_opts_void, uri, host, NULL, error);
+   return mongoc_client_connect (true, use_ssl, ssl_opts_void, uri, host, NULL, MONGOC_SHARED_PTR_NULL, error);
 #endif
 }
 
@@ -1028,6 +1042,12 @@ _mongoc_client_set_ssl_opts_for_single_or_pooled (mongoc_client_t *client, const
       SSL_CTX_free (client->topology->scanner->openssl_ctx);
       client->topology->scanner->openssl_ctx = _mongoc_openssl_ctx_new (&client->ssl_opts);
 #endif
+
+#if defined(MONGOC_ENABLE_SSL_SECURE_CHANNEL)
+      mongoc_shared_ptr_reset (&client->topology->scanner->secure_channel_cred_ptr,
+                               mongoc_secure_channel_cred_new (&client->ssl_opts),
+                               mongoc_secure_channel_cred_deleter);
+#endif
    }
 }
 #endif // MONGOC_ENABLE_SSL

src/libmongoc/src/mongoc/mongoc-secure-channel.c

@@ -671,18 +671,18 @@ mongoc_secure_channel_handshake_step_1 (mongoc_stream_tls_t *tls, char *hostname
    secure_channel->ctxt = (mongoc_secure_channel_ctxt *) bson_malloc0 (sizeof (mongoc_secure_channel_ctxt));
 
    /* https://msdn.microsoft.com/en-us/library/windows/desktop/aa375924.aspx */
-   sspi_status = InitializeSecurityContext (&secure_channel->cred->cred_handle, /* phCredential */
-                                            NULL,                               /* phContext */
-                                            hostname,                           /* pszTargetName */
-                                            secure_channel->req_flags,          /* fContextReq */
-                                            0,                                  /* Reserved1, must be 0 */
-                                            0,                                  /* TargetDataRep, unused */
-                                            NULL,                               /* pInput */
-                                            0,                                  /* Reserved2, must be 0 */
-                                            &secure_channel->ctxt->ctxt_handle, /* phNewContext OUT param */
-                                            &outbuf_desc,                       /* pOutput OUT param */
-                                            &secure_channel->ret_flags,         /* pfContextAttr OUT param */
-                                            &secure_channel->ctxt->time_stamp   /* ptsExpiry OUT param */
+   sspi_status = InitializeSecurityContext (&secure_channel->cred_handle->cred_handle, /* phCredential */
+                                            NULL,                                      /* phContext */
+                                            hostname,                                  /* pszTargetName */
+                                            secure_channel->req_flags,                 /* fContextReq */
+                                            0,                                         /* Reserved1, must be 0 */
+                                            0,                                         /* TargetDataRep, unused */
+                                            NULL,                                      /* pInput */
+                                            0,                                         /* Reserved2, must be 0 */
+                                            &secure_channel->ctxt->ctxt_handle,        /* phNewContext OUT param */
+                                            &outbuf_desc,                              /* pOutput OUT param */
+                                            &secure_channel->ret_flags,                /* pfContextAttr OUT param */
+                                            &secure_channel->ctxt->time_stamp          /* ptsExpiry OUT param */
    );
    if (sspi_status != SEC_I_CONTINUE_NEEDED) {
       // Cast signed SECURITY_STATUS to unsigned DWORD. FormatMessage expects DWORD.
@@ -739,7 +739,7 @@ mongoc_secure_channel_handshake_step_2 (mongoc_stream_tls_t *tls, char *hostname
 
    TRACE ("%s", "SSL/TLS connection with endpoint (step 2/3)");
 
-   if (!secure_channel->cred || !secure_channel->ctxt) {
+   if (!secure_channel->cred_handle || !secure_channel->ctxt) {
       MONGOC_LOG_AND_SET_ERROR (
          error, MONGOC_ERROR_STREAM, MONGOC_ERROR_STREAM_SOCKET, "required TLS credentials or context not provided");
 
@@ -809,7 +809,7 @@ mongoc_secure_channel_handshake_step_2 (mongoc_stream_tls_t *tls, char *hostname
 
       /* https://msdn.microsoft.com/en-us/library/windows/desktop/aa375924.aspx
        */
-      sspi_status = InitializeSecurityContext (&secure_channel->cred->cred_handle,
+      sspi_status = InitializeSecurityContext (&secure_channel->cred_handle->cred_handle,
                                                &secure_channel->ctxt->ctxt_handle,
                                                hostname,
                                                secure_channel->req_flags,
@@ -989,7 +989,7 @@ mongoc_secure_channel_handshake_step_3 (mongoc_stream_tls_t *tls, char *hostname
 
    TRACE ("SSL/TLS connection with %s (step 3/3)", hostname);
 
-   if (!secure_channel->cred) {
+   if (!secure_channel->cred_handle) {
       MONGOC_LOG_AND_SET_ERROR (
          error, MONGOC_ERROR_STREAM, MONGOC_ERROR_STREAM_SOCKET, "required TLS credentials not provided");
       return false;

src/libmongoc/src/mongoc/mongoc-server-monitor.c

@@ -933,6 +933,7 @@ _server_monitor_setup_connection (mongoc_server_monitor_t *server_monitor,
    } else {
       void *ssl_opts_void = NULL;
       void *openssl_ctx_void = NULL;
+      mongoc_shared_ptr secure_channel_cred_ptr = MONGOC_SHARED_PTR_NULL;
 
 #ifdef MONGOC_ENABLE_SSL
       ssl_opts_void = server_monitor->ssl_opts;
@@ -942,12 +943,17 @@ _server_monitor_setup_connection (mongoc_server_monitor_t *server_monitor,
       openssl_ctx_void = server_monitor->topology->scanner->openssl_ctx;
 #endif
 
+#if defined(MONGOC_ENABLE_SSL_SECURE_CHANNEL)
+      secure_channel_cred_ptr = server_monitor->topology->scanner->secure_channel_cred_ptr;
+#endif
+
       server_monitor->stream = mongoc_client_connect (false,
                                                       ssl_opts_void != NULL,
                                                       ssl_opts_void,
                                                       server_monitor->uri,
                                                       &server_monitor->description->host,
                                                       openssl_ctx_void,
+                                                      secure_channel_cred_ptr,
                                                       error);
    }
 

src/libmongoc/src/mongoc/mongoc-stream-tls-private.h

@@ -28,6 +28,8 @@
 #include <openssl/ssl.h>
 #endif
 
+#include <mongoc/mongoc-shared-private.h>
+
 BSON_BEGIN_DECLS
 
 /**
@@ -55,6 +57,13 @@ mongoc_stream_tls_new_with_hostname_and_openssl_context (mongoc_stream_t *base_s
                                                          SSL_CTX *ssl_ctx) BSON_GNUC_WARN_UNUSED_RESULT;
 #endif
 
+#if defined(MONGOC_ENABLE_SSL_SECURE_CHANNEL)
+mongoc_stream_t *
+mongoc_stream_tls_new_with_secure_channel_cred (mongoc_stream_t *base_stream,
+                                                mongoc_ssl_opt_t *opt,
+                                                mongoc_shared_ptr secure_channel_cred_ptr) BSON_GNUC_WARN_UNUSED_RESULT;
+#endif // MONGOC_ENABLE_SSL_SECURE_CHANNEL
+
 BSON_END_DECLS
 
 #endif /* MONGOC_STREAM_TLS_PRIVATE_H */

src/libmongoc/src/mongoc/mongoc-stream-tls-secure-channel-private.h

@@ -22,9 +22,12 @@
 #ifdef MONGOC_ENABLE_SSL_SECURE_CHANNEL
 #include <bson/bson.h>
 
+#include <mongoc/mongoc-shared-private.h>
+
 /* Its mandatory to indicate to Windows who is compiling the code */
 #define SECURITY_WIN32
 #include <security.h>
+#include <schannel.h>
 
 
 BSON_BEGIN_DECLS
@@ -44,9 +47,14 @@ typedef enum {
 typedef struct {
    CredHandle cred_handle;
    TimeStamp time_stamp;
-   PCCERT_CONTEXT cert; /* Owning. Optional client cert. */
 } mongoc_secure_channel_cred_handle;
 
+// `mongoc_secure_channel_cred` may be shared on multiple connections.
+typedef struct _mongoc_secure_channel_cred {
+   PCCERT_CONTEXT cert; /* Owning. Optional client cert. */
+   SCHANNEL_CRED cred;  // TODO: switch to SCH_CREDENTIALS to support TLS v1.3
+} mongoc_secure_channel_cred;
+
 typedef struct {
    CtxtHandle ctxt_handle;
    TimeStamp time_stamp;
@@ -59,7 +67,8 @@ typedef struct {
  */
 typedef struct {
    ssl_connect_state connecting_state;
-   mongoc_secure_channel_cred_handle *cred;
+   mongoc_shared_ptr cred_ptr; // Manages a mongoc_secure_channel_cred.
+   mongoc_secure_channel_cred_handle *cred_handle;
    mongoc_secure_channel_ctxt *ctxt;
    SecPkgContext_StreamSizes stream_sizes;
    size_t encdata_length, decdata_length;
@@ -72,6 +81,20 @@ typedef struct {
    bool recv_connection_closed; /* true if connection closed, regardless how */
 } mongoc_stream_tls_secure_channel_t;
 
+struct _mongoc_ssl_opt_t; // Forward declare. Defined in mongoc-ssl.h.
+struct _mongoc_stream_t;  // Forward declare. Defined in mongoc-stream.h.
+
+mongoc_secure_channel_cred *
+mongoc_secure_channel_cred_new (const struct _mongoc_ssl_opt_t *opt);
+
+// mongoc_secure_channel_cred_deleter is useful as a deleter for mongoc_shared_t.
+void
+mongoc_secure_channel_cred_deleter (void *cred_void);
+
+struct _mongoc_stream_t *
+mongoc_stream_tls_secure_channel_new_with_creds (struct _mongoc_stream_t *base_stream,
+                                                 struct _mongoc_ssl_opt_t *opt,
+                                                 mongoc_shared_ptr cred_ptr /* optional */);
 
 BSON_END_DECLS