s3-decrpc: Introduce gssapi support for dcerpc krb5 auth

2 files changed, 451 insertions, 0 deletions

diff --git a/source3/librpc/rpc/dcerpc_gssapi.c b/source3/librpc/rpc/dcerpc_gssapi.c
new file mode 100644
index 0000000000..e3e5eedac4
--- /dev/null
+++ b/source3/librpc/rpc/dcerpc_gssapi.c
@@ -0,0 +1,404 @@
+/*
+ *  GSSAPI Security Extensions
+ *  RPC Pipe client routines
+ *  Copyright (C) Simo Sorce 2010.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* We support only GSSAPI/KRB5 here */
+
+#include "includes.h"
+#include <gssapi/gssapi.h>
+#include <gssapi/gssapi_krb5.h>
+#include "dcerpc_gssapi.h"
+
+#ifdef HAVE_GSSAPI_H
+
+static char *gse_errstr(TALLOC_CTX *mem_ctx, OM_uint32 maj, OM_uint32 min);
+
+struct gse_context {
+	krb5_context k5ctx;
+	krb5_ccache ccache;
+
+	bool spnego_wrap;
+
+	gss_ctx_id_t gss_ctx;
+
+	OM_uint32 gss_c_flags;
+	gss_OID_desc gss_mech;
+
+	gss_name_t server_name;
+	gss_cred_id_t cli_creds;
+
+	DATA_BLOB session_key;
+
+	bool more_processing;
+};
+
+/* free non talloc dependent contexts */
+static int gse_context_destructor(void *ptr)
+{
+	struct gse_context *gse_ctx;
+	OM_uint32 gss_min, gss_maj;
+
+	gse_ctx = talloc_get_type_abort(ptr, struct gse_context);
+	if (gse_ctx->k5ctx) {
+		if (gse_ctx->ccache) {
+			krb5_cc_close(gse_ctx->k5ctx, gse_ctx->ccache);
+			gse_ctx->ccache = NULL;
+		}
+		krb5_free_context(gse_ctx->k5ctx);
+		gse_ctx->k5ctx = NULL;
+	}
+	if (gse_ctx->gss_ctx != GSS_C_NO_CONTEXT) {
+		gss_maj = gss_delete_sec_context(&gss_min,
+						 &gse_ctx->gss_ctx,
+						 GSS_C_NO_BUFFER);
+	}
+	if (gse_ctx->server_name) {
+		gss_maj = gss_release_name(&gss_min,
+					   &gse_ctx->server_name);
+	}
+
+	return 0;
+}
+
+static NTSTATUS gse_context_init(TALLOC_CTX *mem_ctx,
+				 enum dcerpc_AuthType auth_type,
+				 enum dcerpc_AuthLevel auth_level,
+				 const char *ccache_name,
+				 uint32_t add_gss_c_flags,
+				 struct gse_context **_gse_ctx)
+{
+	struct gse_context *gse_ctx;
+	krb5_error_code k5ret;
+	NTSTATUS status;
+
+	gse_ctx = talloc_zero(mem_ctx, struct gse_context);
+	if (!gse_ctx) {
+		return NT_STATUS_NO_MEMORY;
+	}
+	talloc_set_destructor((TALLOC_CTX *)gse_ctx, gse_context_destructor);
+
+	memcpy(&gse_ctx->gss_mech, gss_mech_krb5, sizeof(gss_OID_desc));
+
+	switch (auth_type) {
+	case DCERPC_AUTH_TYPE_SPNEGO:
+		gse_ctx->spnego_wrap = true;
+		break;
+	case DCERPC_AUTH_TYPE_KRB5:
+		gse_ctx->spnego_wrap = false;
+		break;
+	default:
+		status = NT_STATUS_INVALID_PARAMETER;
+		goto err_out;
+	}
+
+	gse_ctx->gss_c_flags = GSS_C_MUTUAL_FLAG |
+				GSS_C_DELEG_FLAG |
+				GSS_C_DELEG_POLICY_FLAG |
+				GSS_C_REPLAY_FLAG |
+				GSS_C_SEQUENCE_FLAG;
+	switch (auth_level) {
+	case DCERPC_AUTH_LEVEL_INTEGRITY:
+		gse_ctx->gss_c_flags |= GSS_C_INTEG_FLAG;
+		break;
+	case DCERPC_AUTH_LEVEL_PRIVACY:
+		gse_ctx->gss_c_flags |= GSS_C_CONF_FLAG;
+		break;
+	default:
+		break;
+	}
+
+	gse_ctx->gss_c_flags |= add_gss_c_flags;
+
+	/* Initialize Kerberos Context */
+	initialize_krb5_error_table();
+
+	k5ret = krb5_init_context(&gse_ctx->k5ctx);
+	if (k5ret) {
+		DEBUG(0, ("Failed to initialize kerberos context! (%s)\n",
+			  error_message(k5ret)));
+		status = NT_STATUS_INTERNAL_ERROR;
+		goto err_out;
+	}
+
+	if (!ccache_name) {
+		ccache_name = krb5_cc_default_name(gse_ctx->k5ctx);
+	}
+	k5ret = krb5_cc_resolve(gse_ctx->k5ctx, ccache_name,
+				&gse_ctx->ccache);
+	if (k5ret) {
+		DEBUG(1, ("Failed to resolve credential cache! (%s)\n",
+			  error_message(k5ret)));
+		status = NT_STATUS_INTERNAL_ERROR;
+		goto err_out;
+	}
+
+	/* TODO: Should we enforce a enc_types list ?
+	ret = krb5_set_default_tgs_ktypes(gse_ctx->k5ctx, enc_types);
+	*/
+
+	*_gse_ctx = gse_ctx;
+	return NT_STATUS_OK;
+
+err_out:
+	TALLOC_FREE(gse_ctx);
+	return status;
+}
+
+NTSTATUS gse_init_client(TALLOC_CTX *mem_ctx,
+			  enum dcerpc_AuthType auth_type,
+			  enum dcerpc_AuthLevel auth_level,
+			  const char *ccache_name,
+			  const char *server,
+			  const char *service,
+			  const char *username,
+			  const char *password,
+			  uint32_t add_gss_c_flags,
+			  struct pipe_auth_data **_auth)
+{
+	struct pipe_auth_data *auth;
+	struct gse_context *gse_ctx;
+	OM_uint32 gss_maj, gss_min;
+	gss_buffer_desc name_buffer = {0, NULL};
+	gss_OID_set_desc mech_set;
+	NTSTATUS status;
+
+	if (!server || !service) {
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+
+	auth = talloc(mem_ctx, struct pipe_auth_data);
+	if (auth == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	auth->auth_type = auth_type;
+	if (auth_type == DCERPC_AUTH_TYPE_SPNEGO) {
+		auth->spnego_type = PIPE_AUTH_TYPE_SPNEGO_KRB5;
+	}
+	auth->auth_level = auth_level;
+
+	if (!username) {
+		username = "";
+	}
+
+	auth->user_name = talloc_strdup(auth, username);
+	if (!auth->user_name) {
+		status = NT_STATUS_NO_MEMORY;
+		goto err_out;
+	}
+
+	/* Fixme, should we fetch/set the Realm ? */
+	auth->domain = talloc_strdup(auth, "");
+	if (!auth->domain) {
+		status = NT_STATUS_NO_MEMORY;
+		goto err_out;
+	}
+
+	status = gse_context_init(auth, auth_type, auth_level,
+				  ccache_name, add_gss_c_flags,
+				  &gse_ctx);
+	if (!NT_STATUS_IS_OK(status)) {
+		goto err_out;
+	}
+
+	name_buffer.value = talloc_asprintf(auth, "%s@%s", service, server);
+	if (!name_buffer.value) {
+		status = NT_STATUS_NO_MEMORY;
+		goto err_out;
+	}
+	name_buffer.length = strlen((char *)name_buffer.value);
+	gss_maj = gss_import_name(&gss_min, &name_buffer,
+				  GSS_C_NT_HOSTBASED_SERVICE,
+				  &gse_ctx->server_name);
+	if (gss_maj) {
+		DEBUG(0, ("gss_import_name failed for %s, with [%s]\n",
+			  (char *)name_buffer.value,
+			  gse_errstr(auth, gss_maj, gss_min)));
+		status = NT_STATUS_INTERNAL_ERROR;
+		goto err_out;
+	}
+
+	/* TODO: get krb5 ticket using username/password, if no valid
+	 * one already available in ccache */
+
+	mech_set.count = 1;
+	mech_set.elements = &gse_ctx->gss_mech;
+
+	gss_maj = gss_acquire_cred(&gss_min,
+				   gse_ctx->server_name,
+				   GSS_C_INDEFINITE,
+				   &mech_set,
+				   GSS_C_INITIATE,
+				   &gse_ctx->cli_creds,
+				   NULL, NULL);
+	if (gss_maj) {
+		DEBUG(0, ("gss_acquire_creds failed for %s, with [%s]\n",
+			  (char *)name_buffer.value,
+			  gse_errstr(auth, gss_maj, gss_min)));
+		status = NT_STATUS_INTERNAL_ERROR;
+		goto err_out;
+	}
+
+	auth->a_u.gssapi_state = gse_ctx;
+	*_auth = auth;
+	TALLOC_FREE(name_buffer.value);
+	return NT_STATUS_OK;
+
+err_out:
+	TALLOC_FREE(auth);
+	return status;
+}
+
+NTSTATUS gse_get_client_auth_token(TALLOC_CTX *mem_ctx,
+				   struct gse_context *gse_ctx,
+				   DATA_BLOB *token_in,
+				   DATA_BLOB *token_out)
+{
+	OM_uint32 gss_maj, gss_min;
+	gss_buffer_desc in_data;
+	gss_buffer_desc out_data;
+	DATA_BLOB blob = data_blob_null;
+	NTSTATUS status;
+
+	in_data.value = token_in->data;
+	in_data.length = token_in->length;
+
+	gss_maj = gss_init_sec_context(&gss_min,
+					gse_ctx->cli_creds,
+					&gse_ctx->gss_ctx,
+					gse_ctx->server_name,
+					&gse_ctx->gss_mech,
+					gse_ctx->gss_c_flags,
+					0, GSS_C_NO_CHANNEL_BINDINGS,
+					&in_data, NULL, &out_data,
+					NULL, NULL);
+	switch (gss_maj) {
+	case GSS_S_COMPLETE:
+		/* we are done with it */
+		gse_ctx->more_processing = false;
+		status = NT_STATUS_OK;
+		break;
+	case GSS_S_CONTINUE_NEEDED:
+		/* we will need a third leg */
+		gse_ctx->more_processing = true;
+		status = NT_STATUS_MORE_PROCESSING_REQUIRED;
+		break;
+	default:
+		DEBUG(0, ("gss_init_sec_context failed with [%s]\n",
+			  gse_errstr(talloc_tos(), gss_maj, gss_min)));
+		status = NT_STATUS_INTERNAL_ERROR;
+		goto done;
+	}
+
+	blob = data_blob_talloc(mem_ctx, out_data.value, out_data.length);
+	if (!blob.data) {
+		status = NT_STATUS_NO_MEMORY;
+	}
+
+	gss_maj = gss_release_buffer(&gss_min, &out_data);
+
+done:
+	*token_out = blob;
+	return status;
+}
+
+static char *gse_errstr(TALLOC_CTX *mem_ctx, OM_uint32 maj, OM_uint32 min)
+{
+	OM_uint32 gss_min, gss_maj;
+	gss_buffer_desc msg_min;
+	gss_buffer_desc msg_maj;
+	OM_uint32 msg_ctx = 0;
+
+	char *errstr = NULL;
+
+	ZERO_STRUCT(msg_min);
+	ZERO_STRUCT(msg_maj);
+
+	gss_maj = gss_display_status(&gss_min, maj, GSS_C_GSS_CODE,
+				     GSS_C_NO_OID, &msg_ctx, &msg_maj);
+	if (gss_maj) {
+		goto done;
+	}
+	gss_maj = gss_display_status(&gss_min, min, GSS_C_MECH_CODE,
+				     discard_const(gss_mech_krb5),
+				     &msg_ctx, &msg_min);
+	if (gss_maj) {
+		goto done;
+	}
+
+	errstr = talloc_strndup(mem_ctx,
+				(char *)msg_maj.value,
+					msg_maj.length);
+	if (!errstr) {
+		goto done;
+	}
+	errstr = talloc_strdup_append_buffer(errstr, ": ");
+	if (!errstr) {
+		goto done;
+	}
+	errstr = talloc_strndup_append_buffer(errstr,
+						(char *)msg_min.value,
+							msg_min.length);
+	if (!errstr) {
+		goto done;
+	}
+
+done:
+	if (msg_min.value) {
+		gss_maj = gss_release_buffer(&gss_min, &msg_min);
+	}
+	if (msg_maj.value) {
+		gss_maj = gss_release_buffer(&gss_min, &msg_maj);
+	}
+	return errstr;
+}
+
+DATA_BLOB gse_get_session_key(struct gse_context *gse_ctx)
+{
+	return gse_ctx->session_key;
+}
+
+#else /* HAVE_GSSAPI_H */
+
+NTSTATUS gse_init_client(TALLOC_CTX *mem_ctx,
+			  enum dcerpc_AuthType auth_type,
+			  enum dcerpc_AuthLevel auth_level,
+			  const char *ccache_name,
+			  const char *server,
+			  const char *service,
+			  const char *username,
+			  const char *password,
+			  uint32_t add_gss_c_flags,
+			  struct pipe_auth_data **_auth)
+{
+	return NT_STATUS_NOT_IMPLEMENTED;
+}
+
+NTSTATUS gse_gen_client_auth_token(TALLOC_CTX *mem_ctx,
+				   struct gse_context *gse_ctx,
+				   DATA_BLOB *auth_blob)
+{
+	return NT_STATUS_NOT_IMPLEMENTED;
+}
+
+DATA_BLOB gse_get_session_key(struct gse_context *gse_ctx)
+{
+	return data_blob_null;
+}
+
+#endif /* HAVE_GSSAPI_H */
diff --git a/source3/librpc/rpc/dcerpc_gssapi.h b/source3/librpc/rpc/dcerpc_gssapi.h
new file mode 100644
index 0000000000..c172cacc14
--- /dev/null
+++ b/source3/librpc/rpc/dcerpc_gssapi.h
@@ -0,0 +1,47 @@
+/*
+ *  GSSAPI Security Extensions
+ *  RPC Pipe client routines
+ *  Copyright (C) Simo Sorce 2010.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _CLI_PIPE_GSSAPI_H_
+#define _CLI_PIPE_GSSAPI_H_
+
+struct gse_context;
+
+#ifndef GSS_C_DCE_STYLE
+#define GSS_C_DCE_STYLE 0x1000
+#endif
+
+NTSTATUS gse_init_client(TALLOC_CTX *mem_ctx,
+			  enum dcerpc_AuthType auth_type,
+			  enum dcerpc_AuthLevel auth_level,
+			  const char *ccache_name,
+			  const char *server,
+			  const char *service,
+			  const char *username,
+			  const char *password,
+			  uint32_t add_gss_c_flags,
+			  struct pipe_auth_data **_auth);
+
+NTSTATUS gse_get_client_auth_token(TALLOC_CTX *mem_ctx,
+				   struct gse_context *gse_ctx,
+				   DATA_BLOB *token_in,
+				   DATA_BLOB *token_out);
+
+DATA_BLOB gse_get_session_key(struct gse_context *gse_ctx);
+
+#endif /* _CLI_PIPE_GSSAPI_H_ */