s3-auth Add hook to start a GENSEC mech to auth_samba4

Signed-off-by: Andrew Tridgell <tridge@samba.org>

2 files changed, 89 insertions, 1 deletions

diff --git a/source3/auth/auth_samba4.c b/source3/auth/auth_samba4.c
index 03b7884068..cf185f750a 100644
--- a/source3/auth/auth_samba4.c
+++ b/source3/auth/auth_samba4.c
@@ -24,6 +24,9 @@
 #include "auth/auth_sam_reply.h"
 #include "param/param.h"
 #include "source4/lib/events/events.h"
+#include "source4/lib/messaging/messaging.h"
+#include "auth/gensec/gensec.h"
+#include "source4/auth/credentials/credentials.h"
 
 #undef DBGC_CLASS
 #define DBGC_CLASS DBGC_AUTH
@@ -92,6 +95,88 @@ static NTSTATUS check_samba4_security(const struct auth_context *auth_context,
 	return nt_status;
 }
 
+/* Hook to allow GENSEC to handle blob-based authentication
+ * mechanisms, without directly linking the mechansim code */
+static NTSTATUS start_gensec(TALLOC_CTX *mem_ctx, const char *oid_string,
+			      struct gensec_security **gensec_context)
+{
+	NTSTATUS status;
+	struct loadparm_context *lp_ctx;
+	struct tevent_context *event_ctx;
+	TALLOC_CTX *frame = talloc_stackframe();
+	struct gensec_security *gensec_ctx;
+	struct imessaging_context *msg_ctx;
+	struct server_id *server_id;
+	struct cli_credentials *server_credentials;
+
+	lp_ctx = loadparm_init_s3(frame, loadparm_s3_context());
+	if (lp_ctx == NULL) {
+		DEBUG(1, ("loadparm_init_s3 failed\n"));
+		TALLOC_FREE(frame);
+		return NT_STATUS_INVALID_SERVER_STATE;
+	}
+	event_ctx = s4_event_context_init(mem_ctx);
+	if (event_ctx == NULL) {
+		DEBUG(1, ("s4_event_context_init failed\n"));
+		TALLOC_FREE(frame);
+		return NT_STATUS_INVALID_SERVER_STATE;
+	}
+
+	msg_ctx = imessaging_client_init(frame,
+					 lpcfg_imessaging_path(frame, lp_ctx),
+					 event_ctx);
+	if (msg_ctx == NULL) {
+		DEBUG(1, ("imessaging_init failed\n"));
+		TALLOC_FREE(frame);
+		return NT_STATUS_INVALID_SERVER_STATE;
+	}
+
+	server_credentials
+		= cli_credentials_init(frame);
+	if (!server_credentials) {
+		DEBUG(1, ("Failed to init server credentials"));
+		TALLOC_FREE(frame);
+		return NT_STATUS_INVALID_SERVER_STATE;
+	}
+
+	cli_credentials_set_conf(server_credentials, lp_ctx);
+	status = cli_credentials_set_machine_account(server_credentials, lp_ctx);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(10, ("Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(status)));
+		talloc_free(server_credentials);
+		server_credentials = NULL;
+	}
+
+	status = samba_server_gensec_start(mem_ctx,
+					   event_ctx, msg_ctx,
+					   lp_ctx, server_credentials, "cifs",
+					   &gensec_ctx);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
+		TALLOC_FREE(frame);
+		return status;
+	}
+
+	talloc_reparent(frame, gensec_ctx, msg_ctx);
+	talloc_reparent(frame, gensec_ctx, event_ctx);
+	talloc_reparent(frame, gensec_ctx, lp_ctx);
+	talloc_reparent(frame, gensec_ctx, server_credentials);
+
+	gensec_want_feature(gensec_ctx, GENSEC_FEATURE_SESSION_KEY);
+	gensec_want_feature(gensec_ctx, GENSEC_FEATURE_UNIX_TOKEN);
+
+	status = gensec_start_mech_by_oid(gensec_ctx, oid_string);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1, ("Failed to start GENSEC %s server code: %s\n",
+			  gensec_get_name_by_oid(gensec_ctx, oid_string), nt_errstr(status)));
+		TALLOC_FREE(frame);
+		return status;
+	}
+
+	*gensec_context = gensec_ctx;
+	return status;
+}
+
 /* module initialisation */
 static NTSTATUS auth_init_samba4(struct auth_context *auth_context,
 				    const char *param,
@@ -99,12 +184,15 @@ static NTSTATUS auth_init_samba4(struct auth_context *auth_context,
 {
 	struct auth_methods *result;
 
+	gensec_init();
+
 	result = talloc_zero(auth_context, struct auth_methods);
 	if (result == NULL) {
 		return NT_STATUS_NO_MEMORY;
 	}
 	result->name = "samba4";
 	result->auth = check_samba4_security;
+	result->start_gensec = start_gensec;
 
         *auth_method = result;
 	return NT_STATUS_OK;
diff --git a/source3/auth/wscript_build b/source3/auth/wscript_build
index aa6603b85d..28415d84b4 100644
--- a/source3/auth/wscript_build
+++ b/source3/auth/wscript_build
@@ -111,6 +111,6 @@ bld.SAMBA3_MODULE('auth_samba4',
                   subsystem='auth',
                   source='auth_samba4.c',
                   init_function='',
-                  deps='auth4',
+                  deps='auth4 samba_server_gensec gensec',
                   internal_module=bld.SAMBA3_IS_STATIC_MODULE('auth_samba4'),
                   enabled=bld.SAMBA3_IS_ENABLED_MODULE('auth_samba4'))