r4460: Add a new GENSEC module: gensec_gssapi

(disabled by default, set parametric option: gensec:gssapi=yes to enable).

This module backs directly onto GSSAPI, and allows us to sign and seal
GSSAPI/Krb5 connections in particular.  This avoids me reinventing the
entire GSSAPI wheel.

Currently a lot of things are left as default - we will soon start
specifiying OIDs as well as passwords (it uses the keytab only at the
moment).  Tested with our LDAP-* torture tests against Win2k3.

My hope is to use this module to access the new SPNEGO implementation
in Heimdal, to avoid having to standards-verify our own.

Andrew Bartlett
(This used to be commit 14b650c85db14a9bf97e24682b2643b63c51ff35)

3 files changed, 368 insertions, 6 deletions

diff --git a/source4/libcli/auth/gensec.mk b/source4/libcli/auth/gensec.mk
index 66abfd10b7..b66006ce4f 100644
--- a/source4/libcli/auth/gensec.mk
+++ b/source4/libcli/auth/gensec.mk
@@ -24,6 +24,16 @@ REQUIRED_SUBSYSTEMS = NDR_KRB5PAC EXT_LIB_KRB5
 ################################################
 
 ################################################
+# Start MODULE gensec_gssapi
+[MODULE::gensec_gssapi]
+SUBSYSTEM = GENSEC
+INIT_FUNCTION = gensec_gssapi_init
+INIT_OBJ_FILES = libcli/auth/gensec_gssapi.o 
+REQUIRED_SUBSYSTEMS = EXT_LIB_KRB5
+# End MODULE gensec_gssapi
+################################################
+
+################################################
 # Start MODULE gensec_spnego
 [MODULE::gensec_spnego]
 SUBSYSTEM = GENSEC
diff --git a/source4/libcli/auth/gensec_gssapi.c b/source4/libcli/auth/gensec_gssapi.c
new file mode 100644
index 0000000000..c41c3fb2bc
--- /dev/null
+++ b/source4/libcli/auth/gensec_gssapi.c
@@ -0,0 +1,336 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   Kerberos backend for GENSEC
+   
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004
+
+   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 2 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, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+#include "system/kerberos.h"
+#include "system/time.h"
+#include "libcli/auth/kerberos.h"
+#include "auth/auth.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_AUTH
+
+struct gensec_gssapi_state {
+	gss_ctx_id_t gssapi_context;
+	struct gss_channel_bindings_struct *input_chan_bindings;
+	gss_name_t server_name;
+	gss_name_t client_name;
+	int want_flags, got_flags;
+};
+static int gensec_gssapi_destory(void *ptr) 
+{
+	struct gensec_gssapi_state *gensec_gssapi_state = ptr;
+	OM_uint32 maj_stat, min_stat;
+
+	if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
+		maj_stat = gss_delete_sec_context (&min_stat,
+						   &gensec_gssapi_state->gssapi_context,
+						   GSS_C_NO_BUFFER);
+	}
+
+	if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
+		maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
+	}
+	if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
+		maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
+	}
+	return 0;
+}
+
+static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
+{
+	struct gensec_gssapi_state *gensec_gssapi_state;
+
+	gensec_gssapi_state = talloc_p(gensec_security, struct gensec_gssapi_state);
+	if (!gensec_gssapi_state) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	gensec_security->private_data = gensec_gssapi_state;
+
+	gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
+	gensec_gssapi_state->server_name = GSS_C_NO_NAME;
+	gensec_gssapi_state->client_name = GSS_C_NO_NAME;
+
+	talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destory); 
+
+	/* TODO: Fill in channel bindings */
+	gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
+	
+	gensec_gssapi_state->want_flags = 0;
+	gensec_gssapi_state->got_flags = 0;
+
+	if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
+		/* GSSAPI won't give us the session keys */
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+	if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
+		gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
+	}
+	if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
+		gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
+	}
+
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
+{
+	NTSTATUS nt_status;
+	struct gensec_gssapi_state *gensec_gssapi_state;
+
+	nt_status = gensec_gssapi_start(gensec_security);
+	if (!NT_STATUS_IS_OK(nt_status)) {
+		return nt_status;
+	}
+
+	gensec_gssapi_state = gensec_security->private_data;
+
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
+{
+	struct gensec_gssapi_state *gensec_gssapi_state;
+	NTSTATUS nt_status;
+	gss_buffer_desc name_token;
+	OM_uint32 maj_stat, min_stat;
+
+	nt_status = gensec_gssapi_start(gensec_security);
+	if (!NT_STATUS_IS_OK(nt_status)) {
+		return nt_status;
+	}
+
+	gensec_gssapi_state = gensec_security->private_data;
+
+	name_token.value = talloc_asprintf(gensec_gssapi_state, "%s@%s", gensec_get_target_service(gensec_security), 
+					   gensec_get_target_hostname(gensec_security));
+	DEBUG(0, ("name: %s\n", (char *)name_token.value));
+	name_token.length = strlen(name_token.value);
+
+	maj_stat = gss_import_name (&min_stat,
+				    &name_token,
+				    GSS_C_NT_HOSTBASED_SERVICE,
+				    &gensec_gssapi_state->server_name);
+
+
+	if (maj_stat) {
+		return NT_STATUS_UNSUCCESSFUL;
+	}
+	return NT_STATUS_OK;
+}
+
+
+
+/**
+ * Next state function for the GSSAPI GENSEC mechanism
+ * 
+ * @param gensec_gssapi_state GSSAPI State
+ * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
+ * @param in The request, as a DATA_BLOB
+ * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
+ * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent, 
+ *                or NT_STATUS_OK if the user is authenticated. 
+ */
+
+static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security, 
+				   TALLOC_CTX *out_mem_ctx, 
+				   const DATA_BLOB in, DATA_BLOB *out) 
+{
+	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
+	NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
+	OM_uint32 maj_stat, min_stat;
+	OM_uint32 min_stat2;
+	gss_buffer_desc input_token, output_token;
+
+	input_token.length = in.length;
+	input_token.value = in.data;
+
+	switch (gensec_security->gensec_role) {
+	case GENSEC_CLIENT:
+	{
+		maj_stat = gss_init_sec_context(&min_stat, 
+						GSS_C_NO_CREDENTIAL, 
+						&gensec_gssapi_state->gssapi_context, 
+						gensec_gssapi_state->server_name, 
+						GSS_C_NO_OID, 
+						gensec_gssapi_state->want_flags, 
+						0, 
+						gensec_gssapi_state->input_chan_bindings,
+						&input_token, 
+						NULL, 
+						&output_token, 
+						&gensec_gssapi_state->got_flags, /* ret flags */
+						NULL);
+		break;
+	}
+	case GENSEC_SERVER:
+	{
+		maj_stat = gss_accept_sec_context(&min_stat, 
+						  gensec_gssapi_state->gssapi_context, 
+						  GSS_C_NO_CREDENTIAL, 
+						  &input_token, 
+						  gensec_gssapi_state->input_chan_bindings,
+						  &gensec_gssapi_state->client_name, 
+						  NULL /* mech oid */,
+						  &output_token, 
+						  &gensec_gssapi_state->got_flags, 
+						  NULL, 
+						  NULL);
+		break;
+	}
+	default:
+		return NT_STATUS_INVALID_PARAMETER;
+		
+	}
+
+	*out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
+	gss_release_buffer(&min_stat2, &output_token);
+
+	if (maj_stat == GSS_S_COMPLETE) {
+		return NT_STATUS_OK;
+	} else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
+		return NT_STATUS_MORE_PROCESSING_REQUIRED;
+	} else {
+		gss_buffer_desc msg1, msg2;
+		OM_uint32 msg_ctx = 0;
+		
+		msg1.value = NULL;
+		msg2.value = NULL;
+		gss_display_status(&min_stat2, maj_stat, GSS_C_GSS_CODE,
+				   GSS_C_NULL_OID, &msg_ctx, &msg1);
+		gss_display_status(&min_stat2, min_stat, GSS_C_MECH_CODE,
+				   GSS_C_NULL_OID, &msg_ctx, &msg2);
+		DEBUG(1, ("gensec_gssapi_update: %s : %s\n", (char *)msg1.value, (char *)msg2.value));
+		gss_release_buffer(&min_stat2, &msg1);
+		gss_release_buffer(&min_stat2, &msg2);
+
+		return nt_status;
+	}
+	
+}
+
+static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security, 
+				   TALLOC_CTX *mem_ctx, 
+				   const DATA_BLOB *in, 
+				   DATA_BLOB *out)
+{
+	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
+	OM_uint32 maj_stat, min_stat;
+	gss_buffer_desc input_token, output_token;
+	int conf_state;
+	input_token.length = in->length;
+	input_token.value = in->data;
+	
+	maj_stat = gss_wrap(&min_stat, 
+			    gensec_gssapi_state->gssapi_context, 
+			    gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
+			    GSS_C_QOP_DEFAULT,
+			    &input_token,
+			    &conf_state,
+			    &output_token);
+	if (GSS_ERROR(maj_stat)) {
+		return NT_STATUS_ACCESS_DENIED;
+	}
+	*out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
+
+	gss_release_buffer(&min_stat, &output_token);
+
+	if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
+	    && !conf_state) {
+		return NT_STATUS_ACCESS_DENIED;
+	}
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security, 
+				     TALLOC_CTX *mem_ctx, 
+				     const DATA_BLOB *in, 
+				     DATA_BLOB *out)
+{
+	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
+	OM_uint32 maj_stat, min_stat;
+	gss_buffer_desc input_token, output_token;
+	int conf_state;
+	gss_qop_t qop_state;
+	input_token.length = in->length;
+	input_token.value = in->data;
+	
+	maj_stat = gss_unwrap(&min_stat, 
+			      gensec_gssapi_state->gssapi_context, 
+			      &input_token,
+			      &output_token, 
+			      &conf_state,
+			      &qop_state);
+	if (GSS_ERROR(maj_stat)) {
+		return NT_STATUS_ACCESS_DENIED;
+	}
+	*out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
+
+	gss_release_buffer(&min_stat, &output_token);
+	
+	if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
+	    && !conf_state) {
+		return NT_STATUS_ACCESS_DENIED;
+	}
+	return NT_STATUS_OK;
+}
+
+static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security, 
+				       uint32 feature) 
+{
+	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
+	if (feature & GENSEC_FEATURE_SIGN) {
+		return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
+	}
+	if (feature & GENSEC_FEATURE_SEAL) {
+		return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
+	}
+	return False;
+}
+
+static const struct gensec_security_ops gensec_gssapi_security_ops = {
+	.name		= "gssapi",
+	.oid            = GENSEC_OID_KERBEROS5,
+	.client_start   = gensec_gssapi_client_start,
+	.server_start   = gensec_gssapi_server_start,
+	.update 	= gensec_gssapi_update,
+	.wrap           = gensec_gssapi_wrap,
+	.unwrap         = gensec_gssapi_unwrap,
+	.have_feature   = gensec_gssapi_have_feature
+
+};
+
+NTSTATUS gensec_gssapi_init(void)
+{
+	NTSTATUS ret;
+
+	ret = gensec_register(&gensec_gssapi_security_ops);
+	if (!NT_STATUS_IS_OK(ret)) {
+		DEBUG(0,("Failed to register '%s' gensec backend!\n",
+			gensec_gssapi_security_ops.name));
+		return ret;
+	}
+
+	return ret;
+}
diff --git a/source4/libcli/auth/spnego.c b/source4/libcli/auth/spnego.c
index f13bbc11b4..8b4be6eb75 100644
--- a/source4/libcli/auth/spnego.c
+++ b/source4/libcli/auth/spnego.c
@@ -42,6 +42,7 @@ struct spnego_state {
 	enum spnego_message_type expected_packet;
 	enum spnego_state_position state_position;
 	struct gensec_security *sub_sec_security;
+	BOOL no_response_expected;
 };
 
 
@@ -57,6 +58,7 @@ static NTSTATUS gensec_spnego_client_start(struct gensec_security *gensec_securi
 	spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
 	spnego_state->state_position = SPNEGO_CLIENT_START;
 	spnego_state->sub_sec_security = NULL;
+	spnego_state->no_response_expected = False;
 
 	gensec_security->private_data = spnego_state;
 	return NT_STATUS_OK;
@@ -74,6 +76,7 @@ static NTSTATUS gensec_spnego_server_start(struct gensec_security *gensec_securi
 	spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
 	spnego_state->state_position = SPNEGO_SERVER_START;
 	spnego_state->sub_sec_security = NULL;
+	spnego_state->no_response_expected = False;
 
 	gensec_security->private_data = spnego_state;
 	return NT_STATUS_OK;
@@ -374,7 +377,7 @@ static NTSTATUS gensec_spnego_client_negTokenInit(struct gensec_security *gensec
 	}
 	nt_status = gensec_update(spnego_state->sub_sec_security,
 				  out_mem_ctx, in, &unwrapped_out);
-	if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
+	if (NT_STATUS_IS_OK(nt_status) || NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 		struct spnego_data spnego_out;
 		spnego_out.type = SPNEGO_NEG_TOKEN_INIT;
 		spnego_out.negTokenInit.mechTypes = mechTypes;
@@ -390,7 +393,12 @@ static NTSTATUS gensec_spnego_client_negTokenInit(struct gensec_security *gensec
 		/* set next state */
 		spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 		spnego_state->state_position = SPNEGO_CLIENT_TARG;
-		return nt_status;
+		
+		if (NT_STATUS_IS_OK(nt_status)) {
+			spnego_state->no_response_expected = True;
+		}
+
+		return NT_STATUS_MORE_PROCESSING_REQUIRED;
 	} 
 	talloc_free(spnego_state->sub_sec_security);
 	spnego_state->sub_sec_security = NULL;
@@ -601,6 +609,10 @@ static NTSTATUS gensec_spnego_update(struct gensec_security *gensec_security, TA
 		/* set next state */
 		spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 		spnego_state->state_position = SPNEGO_CLIENT_TARG;
+
+		if (NT_STATUS_IS_OK(nt_status)) {
+			spnego_state->no_response_expected = True;
+		}
 		
 		return NT_STATUS_MORE_PROCESSING_REQUIRED;
 	}
@@ -672,10 +684,14 @@ static NTSTATUS gensec_spnego_update(struct gensec_security *gensec_security, TA
 			return NT_STATUS_ACCESS_DENIED;
 		}
 
-		nt_status = gensec_update(spnego_state->sub_sec_security,
-					  out_mem_ctx, 
-					  spnego.negTokenTarg.responseToken, 
-					  &unwrapped_out);
+		if (spnego_state->no_response_expected) {
+			nt_status = NT_STATUS_OK;
+		} else {
+			nt_status = gensec_update(spnego_state->sub_sec_security,
+						  out_mem_ctx, 
+						  spnego.negTokenTarg.responseToken, 
+						  &unwrapped_out);
+		} 
 		
 		
 		if (NT_STATUS_IS_OK(nt_status)