r10066: This is the second in my patches to work on Samba4's kerberos support,

with an aim to make the code simpiler and more correct.

Gone is the old (since the very early Samba 3.0 krb5 days) 'iterate over
all keytypes)' code in gensec_krb5, we now follow the approach used in
gensec_gssapi, and use a keytab.

I have also done a lot of work in the GSSAPI code, to try and reduce
the diff between us and upstream heimdal.  It was becoming hard to
track patches in this code, and I also want this patch (the DCE_STYLE
support) to be in a 'manageable' state for when lha considers it for
merging.  (metze assures me it still has memory leak problems, but
I've started to address some of that).

This patch also includes a simple update of other code to current
heimdal, as well as changes we need for better PAC verification.

On the PAC side of things we now match windows member servers by
checking the name and authtime on an incoming PAC.  Not generating these
right was the cause of the PAC pain, and so now both the main code and
torture test validate this behaviour.

One thing doesn't work with this patch:
 - the sealing of RPC pipes with kerberos, Samba -> Samba seems
broken.  I'm pretty sure this is related to AES, and the need to break
apart the gss_wrap interface.

Andrew Bartlett
(This used to be commit a3aba57c00a9c5318f4706db55d03f64e8bea60c)

1 files changed, 77 insertions, 37 deletions

diff --git a/source4/auth/gensec/gensec_gssapi.c b/source4/auth/gensec/gensec_gssapi.c
index 6316b52bad..c3f7c52085 100644
--- a/source4/auth/gensec/gensec_gssapi.c
+++ b/source4/auth/gensec/gensec_gssapi.c
@@ -118,7 +118,7 @@ static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 	/* 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->want_flags = GSS_C_MUTUAL_FLAG;
 	gensec_gssapi_state->got_flags = 0;
 
 	gensec_gssapi_state->session_key = data_blob(NULL, 0);
@@ -388,12 +388,15 @@ static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 		
 	}
 
-	*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) {
+		*out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
+		gss_release_buffer(&min_stat2, &output_token);
+
 		return NT_STATUS_OK;
 	} else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
+		*out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
+		gss_release_buffer(&min_stat2, &output_token);
+
 		return NT_STATUS_MORE_PROCESSING_REQUIRED;
 	} else {
 		if (maj_stat == GSS_S_FAILURE
@@ -427,12 +430,12 @@ static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 			    &conf_state,
 			    &output_token);
 	if (GSS_ERROR(maj_stat)) {
-		DEBUG(1, ("GSS Wrap failed: %s\n", 
+		DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n", 
 			  gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 		return NT_STATUS_ACCESS_DENIED;
 	}
-	*out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 
+	*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)
@@ -462,12 +465,12 @@ static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 			      &conf_state,
 			      &qop_state);
 	if (GSS_ERROR(maj_stat)) {
-		DEBUG(1, ("GSS UnWrap failed: %s\n", 
+		DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n", 
 			  gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 		return NT_STATUS_ACCESS_DENIED;
 	}
-	*out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 
+	*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)
@@ -506,7 +509,7 @@ static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_securit
 			    &conf_state,
 			    &output_token);
 	if (GSS_ERROR(maj_stat)) {
-		DEBUG(1, ("GSS Wrap failed: %s\n", 
+		DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n", 
 			  gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 		return NT_STATUS_ACCESS_DENIED;
 	}
@@ -546,7 +549,7 @@ static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_secur
 	gss_qop_t qop_state;
 	DATA_BLOB in;
 
-	dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
+	dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
 
 	in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 
@@ -563,7 +566,7 @@ static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_secur
 			      &conf_state,
 			      &qop_state);
 	if (GSS_ERROR(maj_stat)) {
-		DEBUG(1, ("GSS UnWrap failed: %s\n", 
+		DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n", 
 			  gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 		return NT_STATUS_ACCESS_DENIED;
 	}
@@ -688,7 +691,7 @@ static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
 		}
 	}
 	if (feature & GENSEC_FEATURE_DCE_STYLE) {
-		return True;
+		return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
 	}
 	if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
 		return True;
@@ -744,15 +747,21 @@ static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_securi
 	struct auth_serversupplied_info *server_info = NULL;
 	struct auth_session_info *session_info = NULL;
 	struct PAC_LOGON_INFO *logon_info;
-	char *p;
-	char *principal;
-	const char *account_name;
-	const char *realm;
 	OM_uint32 maj_stat, min_stat;
 	gss_buffer_desc name_token;
 	gss_buffer_desc pac;
 	krb5_keyblock *keyblock;
+	time_t authtime;
+	krb5_principal principal;
+	char *principal_string;
 	
+	if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
+	    || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, 
+		       gensec_gssapi_state->gss_oid->length) != 0)) {
+		DEBUG(1, ("NO session info available for this mech\n"));
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+		
 	mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context"); 
 	NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
 
@@ -764,49 +773,56 @@ static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_securi
 		return NT_STATUS_FOOBAR;
 	}
 
-	principal = talloc_strndup(mem_ctx, name_token.value, name_token.length);
+	principal_string = talloc_strndup(mem_ctx, name_token.value, name_token.length);
 
 	gss_release_buffer(&min_stat, &name_token);
 
-	if (!principal) {
+	if (!principal_string) {
 		talloc_free(mem_ctx);
 		return NT_STATUS_NO_MEMORY;
 	}
 
-	p = strchr(principal, '@');
-	if (p) {
-		*p = '\0';
-		p++;
-		realm = p;
-	} else {
-		realm = lp_realm();
-	}
-	account_name = principal;
-	
 	maj_stat = gss_krb5_copy_service_keyblock(&min_stat, 
 						  gensec_gssapi_state->gssapi_context, 
 						  &keyblock);
 
-	maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat, 
-							       gensec_gssapi_state->gssapi_context, 
-							       KRB5_AUTHDATA_IF_RELEVANT,
-							       &pac);
+	if (maj_stat == 0) {
+		maj_stat = gsskrb5_extract_authtime_from_sec_context(&min_stat,
+								     gensec_gssapi_state->gssapi_context, 
+								     &authtime);
+	}
+
+	if (maj_stat == 0) {
+		maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat, 
+								       gensec_gssapi_state->gssapi_context, 
+								       KRB5_AUTHDATA_IF_RELEVANT,
+								       &pac);
+	}
 	
 	if (maj_stat == 0) {
+		krb5_error_code ret;
 		DATA_BLOB pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
 		pac_blob = unwrap_pac(mem_ctx, &pac_blob);
 		gss_release_buffer(&min_stat, &pac);
+
+		ret = krb5_parse_name(gensec_gssapi_state->smb_krb5_context->krb5_context,
+				      principal_string, &principal);
+		if (ret) {
+			talloc_free(mem_ctx);
+			return NT_STATUS_INVALID_PARAMETER;
+		}
 		
 		/* decode and verify the pac */
 		nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info, pac_blob,
 						    gensec_gssapi_state->smb_krb5_context->krb5_context,
-						    NULL, keyblock);
+						    NULL, keyblock, principal, authtime);
+		krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
 
 		if (NT_STATUS_IS_OK(nt_status)) {
 			union netr_Validation validation;
 			validation.sam3 = &logon_info->info3;
 			nt_status = make_server_info_netlogon_validation(gensec_gssapi_state, 
-									 account_name,
+									 NULL,
 									 3, &validation,
 									 &server_info); 
 			if (!NT_STATUS_IS_OK(nt_status)) {
@@ -819,6 +835,9 @@ static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_securi
 	}
 	
 	if (maj_stat) {
+		krb5_error_code ret;
+		DATA_BLOB user_sess_key = data_blob(NULL, 0);
+		DATA_BLOB lm_sess_key = data_blob(NULL, 0);
 		/* IF we have the PAC - otherwise we need to get this
 		 * data from elsewere - local ldb, or (TODO) lookup of some
 		 * kind... 
@@ -827,12 +846,32 @@ static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_securi
 		 * no PAC present
 		 */
 
-		DATA_BLOB user_sess_key = data_blob(NULL, 0);
-		DATA_BLOB lm_sess_key = data_blob(NULL, 0);
-		/* TODO: should we pass the krb5 session key in here? */
+		char *account_name;
+		const char *realm;
+		ret = krb5_parse_name(gensec_gssapi_state->smb_krb5_context->krb5_context,
+				      principal_string, &principal);
+		if (ret) {
+			talloc_free(mem_ctx);
+			return NT_STATUS_INVALID_PARAMETER;
+		}
+		
+		realm = krb5_principal_get_realm(gensec_gssapi_state->smb_krb5_context->krb5_context, 
+						 principal);
+		ret = krb5_unparse_name_norealm(gensec_gssapi_state->smb_krb5_context->krb5_context, 
+						principal, &account_name);
+		if (ret) {
+			krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
+			talloc_free(mem_ctx);
+			return NT_STATUS_NO_MEMORY;
+		}
+
+		DEBUG(1, ("Unable to use PAC, resorting to local user lookup!\n"));
 		nt_status = sam_get_server_info(mem_ctx, account_name, realm,
 						user_sess_key, lm_sess_key,
 						&server_info);
+		free(account_name);
+		krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
+
 		if (!NT_STATUS_IS_OK(nt_status)) {
 			talloc_free(mem_ctx);
 			return nt_status;
@@ -841,6 +880,7 @@ static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_securi
 
 	/* references the server_info into the session_info */
 	nt_status = auth_generate_session_info(gensec_gssapi_state, server_info, &session_info);
+	talloc_free(mem_ctx);
 	talloc_free(server_info);
 	NT_STATUS_NOT_OK_RETURN(nt_status);