r11543: A major upgrade to our KDC and PAC handling.

We now put the PAC in the AS-REP, so that the client has it in the
TGT.  We then validate it (and re-sign it) on a TGS-REQ, ie when the
client wants a ticket.

This should also allow us to interop with windows KDCs.

If we get an invalid PAC at the TGS stage, we just drop it.

I'm slowly trying to move the application logic out of hdb-ldb.c, and
back in with the rest of Samba's auth system, for consistancy.  This
continues that trend.

Andrew Bartlett
(This used to be commit 36973b1eef7db5983cce76ba241e54d5f925c69c)

1 files changed, 293 insertions, 24 deletions

diff --git a/source4/kdc/pac-glue.c b/source4/kdc/pac-glue.c
index ae306b4062..03b53fa3af 100644
--- a/source4/kdc/pac-glue.c
+++ b/source4/kdc/pac-glue.c
@@ -23,42 +23,41 @@
 
 #include "includes.h"
 #include "kdc/kdc.h"
-#include "kdc/pac-glue.h" /* Ensure we don't get this prototype wrong, as that could be painful */
-
- krb5_error_code samba_get_pac(krb5_context context, 
-			       struct krb5_kdc_configuration *config,
-			       krb5_principal client, 
-			       krb5_keyblock *krbtgt_keyblock, 
-			       krb5_keyblock *server_keyblock, 
-			       time_t tgs_authtime,
-			       krb5_data *pac)
+#include "include/ads.h"
+#include "lib/ldb/include/ldb.h"
+#include "heimdal/lib/krb5/krb5_locl.h"
+#include "librpc/gen_ndr/krb5pac.h"
+#include "auth/auth.h"
+
+/* Given the right private pointer from hdb_ldb, get a PAC from the attached ldb messages */
+static krb5_error_code samba_get_pac(krb5_context context, 
+				     struct hdb_ldb_private *private,
+				     krb5_principal client, 
+				     krb5_keyblock *krbtgt_keyblock, 
+				     krb5_keyblock *server_keyblock, 
+				     time_t tgs_authtime,
+				     krb5_data *pac)
 {
 	krb5_error_code ret;
 	NTSTATUS nt_status;
 	struct auth_serversupplied_info *server_info;
 	DATA_BLOB tmp_blob;
-	char *principal_string;
-	TALLOC_CTX *mem_ctx = talloc_named(config, 0, "samba_get_pac context");
+	TALLOC_CTX *mem_ctx = talloc_named(private, 0, "samba_get_pac context");
+
 	if (!mem_ctx) {
 		return ENOMEM;
 	}
 
-	ret = krb5_unparse_name(context, client, &principal_string);
-
-	if (ret != 0) {
-		krb5_set_error_string(context, "get pac: could not unparse principal");
-		krb5_warnx(context, "get pac: could not unparse principal");
-		talloc_free(mem_ctx);
-		return ret;
-	}
-
-	nt_status = sam_get_server_info_principal(mem_ctx, principal_string,
-						  &server_info);
-	free(principal_string);
+	nt_status = authsam_make_server_info(mem_ctx, private->samdb, 
+					     private->msg, 
+					     private->realm_ref_msg,
+					     data_blob(NULL, 0),
+					     data_blob(NULL, 0),
+					     &server_info);
 	if (!NT_STATUS_IS_OK(nt_status)) {
 		DEBUG(0, ("Getting user info for PAC failed: %s\n",
 			  nt_errstr(nt_status)));
-		return EINVAL;
+		return ENOMEM;
 	}
 
 	ret = kerberos_create_pac(mem_ctx, server_info, 
@@ -80,3 +79,273 @@
 	talloc_free(mem_ctx);
 	return ret;
 }
+
+/* Wrap the PAC in the right ASN.1.  Will always free 'pac', on success or failure */
+krb5_error_code wrap_pac(krb5_context context, krb5_data *pac, AuthorizationData **out) 
+{
+	krb5_error_code ret;
+
+	unsigned char *buf;
+	size_t buf_size;
+	size_t len;
+	
+	AD_IF_RELEVANT if_relevant;
+	AuthorizationData *auth_data;
+
+	if_relevant.len = 1;
+	if_relevant.val = malloc(sizeof(*if_relevant.val));
+	if (!if_relevant.val) {
+		krb5_data_free(pac);
+		*out = NULL;
+		return ENOMEM;
+	}
+
+	if_relevant.val[0].ad_type = KRB5_AUTHDATA_WIN2K_PAC;
+	if_relevant.val[0].ad_data.data = NULL;
+	if_relevant.val[0].ad_data.length = 0;
+	
+	/* pac.data will be freed with this */
+	if_relevant.val[0].ad_data.data = pac->data;
+	if_relevant.val[0].ad_data.length = pac->length;
+	
+	ASN1_MALLOC_ENCODE(AuthorizationData, buf, buf_size, &if_relevant, &len, ret);
+	free_AuthorizationData(&if_relevant);
+	if (ret) {
+		*out = NULL;
+		return ret;
+	}		
+	
+	auth_data = malloc(sizeof(*auth_data));
+	if (!auth_data) {
+		free(buf);
+		*out = NULL;
+		return ret;
+	}		
+	auth_data->len = 1;
+	auth_data->val = malloc(sizeof(*auth_data->val));
+	if (!auth_data->val) {
+		free(buf);
+		free(auth_data);
+		*out = NULL;
+		return ret;
+	}
+	auth_data->val[0].ad_type = KRB5_AUTHDATA_IF_RELEVANT;
+	auth_data->val[0].ad_data.length = len;
+	auth_data->val[0].ad_data.data = buf;
+
+	*out = auth_data;
+	return 0;
+}
+
+
+/* Given a hdb_entry, create a PAC out of the private data 
+
+   Don't create it if the client has the UF_NO_AUTH_DATA_REQUIRED bit
+   set, or if they specificaly asked not to get it.
+*/
+
+ krb5_error_code hdb_ldb_authz_data_as_req(krb5_context context, struct hdb_entry_ex *entry_ex, 
+					   METHOD_DATA* pa_data_seq,
+					   time_t authtime,
+					   EncryptionKey *tgtkey,
+					   EncryptionKey *sessionkey,
+					   AuthorizationData **out)
+{
+	krb5_error_code ret;
+	int i;
+	krb5_data pac;
+	krb5_boolean pac_wanted = TRUE;
+	unsigned int userAccountControl;
+	struct PA_PAC_REQUEST pac_request;
+	struct hdb_ldb_private *private = talloc_get_type(entry_ex->private, struct hdb_ldb_private);
+	
+	/* The user account may be set not to want the PAC */
+	userAccountControl = ldb_msg_find_uint(private->msg, "userAccountControl", 0);
+	if (userAccountControl & UF_NO_AUTH_DATA_REQUIRED) {
+		*out = NULL;
+		return 0;
+	}
+
+	/* The user may not want a PAC */
+	for (i=0; i<pa_data_seq->len; i++) {
+		if (pa_data_seq->val[i].padata_type == KRB5_PADATA_PA_PAC_REQUEST) {
+			ret = decode_PA_PAC_REQUEST(pa_data_seq->val[i].padata_value.data, 
+						    pa_data_seq->val[i].padata_value.length, 
+						    &pac_request, NULL);
+			if (ret == 0) {
+				pac_wanted = !!pac_request.include_pac;
+			}
+			free_PA_PAC_REQUEST(&pac_request);
+			break;
+		}
+	}
+
+	if (!pac_wanted) {
+		*out = NULL;
+		return 0;
+	}	
+
+	/* Get PAC from Samba */
+	ret = samba_get_pac(context,
+			    private,
+			    entry_ex->entry.principal,
+			    tgtkey,
+			    tgtkey,
+			    authtime,
+			    &pac);
+
+	if (ret) {
+		*out = NULL;
+		return ret;
+	}
+	
+	return wrap_pac(context, &pac, out);
+}
+
+/* Resign (and reform, including possibly new groups) a PAC */
+
+ krb5_error_code hdb_ldb_authz_data_tgs_req(krb5_context context, struct hdb_entry_ex *entry_ex, 
+					    krb5_principal client, 
+					    AuthorizationData *in, 
+					    time_t authtime,
+					    EncryptionKey *tgtkey,
+					    EncryptionKey *servicekey,
+					    EncryptionKey *sessionkey,
+					    AuthorizationData **out)
+{
+	NTSTATUS nt_status;
+	krb5_error_code ret;
+
+	unsigned int userAccountControl;
+
+	struct hdb_ldb_private *private = talloc_get_type(entry_ex->private, struct hdb_ldb_private);
+	krb5_data k5pac_in, k5pac_out;
+	DATA_BLOB pac_in, pac_out;
+
+	struct PAC_LOGON_INFO *logon_info;
+	union netr_Validation validation;
+	struct auth_serversupplied_info *server_info_out;
+
+	krb5_boolean found = FALSE;
+	TALLOC_CTX *mem_ctx;
+	
+	/* The service account may be set not to want the PAC */
+	userAccountControl = ldb_msg_find_uint(private->msg, "userAccountControl", 0);
+	if (userAccountControl & UF_NO_AUTH_DATA_REQUIRED) {
+		*out = NULL;
+		return 0;
+	}
+
+	ret = _krb5_find_type_in_ad(context, KRB5_AUTHDATA_WIN2K_PAC,
+				    &k5pac_in, &found, sessionkey, in);
+	if (ret || !found) {
+		*out = NULL;
+		return 0;
+	}
+
+	mem_ctx = talloc_new(private);
+	if (!mem_ctx) {
+		krb5_data_free(&k5pac_in);
+		*out = NULL;
+		return ENOMEM;
+	}
+
+	pac_in = data_blob_talloc(mem_ctx, k5pac_in.data, k5pac_in.length);
+	krb5_data_free(&k5pac_in);
+	if (!pac_in.data) {
+		talloc_free(mem_ctx);
+		*out = NULL;
+		return ENOMEM;
+	}
+		
+	/* Parse the PAC again, for the logon info */
+	nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info,
+					    pac_in,
+					    context,
+					    tgtkey, 
+					    tgtkey, 
+					    client, authtime, 
+					    &ret);
+
+	if (!NT_STATUS_IS_OK(nt_status)) {
+		DEBUG(1, ("Failed to parse PAC in TGT: %s/%s\n", 
+			  nt_errstr(nt_status), error_message(ret)));
+		talloc_free(mem_ctx);
+		*out = NULL;
+		return ret;
+	}
+
+	/* Pull this right into the normal auth sysstem structures */
+	validation.sam3 = &logon_info->info3;
+	nt_status = make_server_info_netlogon_validation(mem_ctx,
+							 "",
+							 3, &validation,
+							 &server_info_out); 
+	if (!NT_STATUS_IS_OK(nt_status)) {
+		talloc_free(mem_ctx);
+		*out = NULL;
+		return ENOMEM;
+	}
+
+	/* And make a new PAC, possibly containing new groups */
+	ret = kerberos_create_pac(mem_ctx, 
+				  server_info_out,
+				  context,
+				  tgtkey,
+				  servicekey,
+				  client,
+				  authtime,
+				  &pac_out);
+
+	if (ret != 0) {
+		talloc_free(mem_ctx);
+		*out = NULL;
+		return ret;
+	}
+
+	ret = krb5_data_copy(&k5pac_out, pac_out.data, pac_out.length);
+	if (ret != 0) {
+		talloc_free(mem_ctx);
+		*out = NULL;
+		return ret;
+	}
+
+	return wrap_pac(context, &k5pac_out, out);
+}
+
+/* Given an hdb entry (and in particular it's private member), consult
+ * the account_ok routine in auth/auth_sam.c for consistancy */
+
+ krb5_error_code hdb_ldb_check_client_access(krb5_context context, hdb_entry_ex *entry_ex, 
+					    HostAddresses *addresses)
+{
+	krb5_error_code ret;
+	NTSTATUS nt_status;
+	TALLOC_CTX *tmp_ctx = talloc_new(entry_ex->private);
+	struct hdb_ldb_private *private = talloc_get_type(entry_ex->private, struct hdb_ldb_private);
+	char *name, *workstation = NULL;
+	if (!tmp_ctx) {
+		return ENOMEM;
+	}
+	
+	ret = krb5_unparse_name(context, entry_ex->entry.principal, &name);
+	if (ret != 0) {
+		talloc_free(tmp_ctx);
+	}
+	nt_status = authsam_account_ok(tmp_ctx, 
+				       private->samdb, 
+				       MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT | MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT,
+				       private->msg,
+				       private->realm_ref_msg,
+				       workstation,
+				       name);
+	free(name);
+
+	/* TODO:  Need a more complete mapping of NTSTATUS to krb5kdc errors */
+
+	if (!NT_STATUS_IS_OK(nt_status)) {
+		return KRB5KDC_ERR_POLICY;
+	}
+	return 0;
+}
+