1 files changed, 266 insertions, 0 deletions
diff --git a/source4/libcli/auth/kerberos_verify.c b/source4/libcli/auth/kerberos_verify.c
new file mode 100644
index 0000000000..805a3f570f
--- /dev/null
+++ b/source4/libcli/auth/kerberos_verify.c
@@ -0,0 +1,266 @@
+/* 
+   Unix SMB/CIFS implementation.
+   kerberos utility library
+   Copyright (C) Andrew Tridgell 2001
+   Copyright (C) Remus Koos 2001
+   Copyright (C) Luke Howard 2003   
+   Copyright (C) Guenther Deschner 2003
+   Copyright (C) Jim McDonough (jmcd@us.ibm.com) 2003
+   
+   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"
+
+#ifdef HAVE_KRB5
+
+/*
+  verify an incoming ticket and parse out the principal name and 
+  authorization_data if available 
+*/
+NTSTATUS ads_verify_ticket(const char *realm, const DATA_BLOB *ticket, 
+			   char **principal, DATA_BLOB *auth_data,
+			   DATA_BLOB *ap_rep,
+			   DATA_BLOB *session_key)
+{
+	NTSTATUS sret = NT_STATUS_LOGON_FAILURE;
+	krb5_context context = NULL;
+	krb5_auth_context auth_context = NULL;
+	krb5_data packet;
+	krb5_ticket *tkt = NULL;
+	krb5_rcache rcache = NULL;
+	int ret, i;
+	krb5_keyblock *key = NULL;
+
+	krb5_principal host_princ;
+	char *host_princ_s = NULL;
+	BOOL free_host_princ = False;
+	BOOL got_replay_mutex = False;
+
+	fstring myname;
+	char *password_s = NULL;
+	krb5_data password;
+	krb5_enctype *enctypes = NULL;
+#if 0
+	krb5_address local_addr;
+	krb5_address remote_addr;
+#endif
+	BOOL auth_ok = False;
+
+	ZERO_STRUCT(packet);
+	ZERO_STRUCT(password);
+	ZERO_STRUCTP(auth_data);
+	ZERO_STRUCTP(ap_rep);
+
+	if (!secrets_init()) {
+		DEBUG(1,("ads_verify_ticket: secrets_init failed\n"));
+		return NT_STATUS_LOGON_FAILURE;
+	}
+
+	password_s = secrets_fetch_machine_password(lp_workgroup());
+	if (!password_s) {
+		DEBUG(1,("ads_verify_ticket: failed to fetch machine password\n"));
+		return NT_STATUS_LOGON_FAILURE;
+	}
+
+	password.data = password_s;
+	password.length = strlen(password_s);
+
+	ret = krb5_init_context(&context);
+	if (ret) {
+		DEBUG(1,("ads_verify_ticket: krb5_init_context failed (%s)\n", error_message(ret)));
+		return NT_STATUS_LOGON_FAILURE;
+	}
+
+	ret = krb5_set_default_realm(context, realm);
+	if (ret) {
+		DEBUG(1,("ads_verify_ticket: krb5_set_default_realm failed (%s)\n", error_message(ret)));
+		sret = NT_STATUS_LOGON_FAILURE;
+		goto out;
+	}
+
+	/* This whole process is far more complex than I would
+           like. We have to go through all this to allow us to store
+           the secret internally, instead of using /etc/krb5.keytab */
+
+	ret = krb5_auth_con_init(context, &auth_context);
+	if (ret) {
+		DEBUG(1,("ads_verify_ticket: krb5_auth_con_init failed (%s)\n", error_message(ret)));
+		sret = NT_STATUS_LOGON_FAILURE;
+		goto out;
+	}
+
+	fstrcpy(myname, global_myname());
+	strlower_m(myname);
+	asprintf(&host_princ_s, "HOST/%s@%s", myname, lp_realm());
+	ret = krb5_parse_name(context, host_princ_s, &host_princ);
+	if (ret) {
+		DEBUG(1,("ads_verify_ticket: krb5_parse_name(%s) failed (%s)\n",
+					host_princ_s, error_message(ret)));
+		sret = NT_STATUS_LOGON_FAILURE;
+		goto out;
+	}
+
+	free_host_princ = True;
+
+	/*
+	 * JRA. We must set the rcache here. This will prevent replay attacks.
+	 */
+
+	ret = krb5_get_server_rcache(context, krb5_princ_component(context, host_princ, 0), &rcache);
+	if (ret) {
+		DEBUG(1,("ads_verify_ticket: krb5_get_server_rcache failed (%s)\n", error_message(ret)));
+		sret = NT_STATUS_LOGON_FAILURE;
+		goto out;
+	}
+
+	ret = krb5_auth_con_setrcache(context, auth_context, rcache);
+	if (ret) {
+		DEBUG(1,("ads_verify_ticket: krb5_auth_con_setrcache failed (%s)\n", error_message(ret)));
+		sret = NT_STATUS_LOGON_FAILURE;
+		goto out;
+	}
+
+	/* CIFS doesn't use addresses in tickets. This would breat NAT. JRA */
+
+	if ((ret = get_kerberos_allowed_etypes(context, &enctypes))) {
+		DEBUG(1,("ads_verify_ticket: krb5_get_permitted_enctypes failed (%s)\n", 
+			 error_message(ret)));
+		sret = NT_STATUS_LOGON_FAILURE;
+		goto out;
+	}
+
+	/* Lock a mutex surrounding the replay as there is no locking in the MIT krb5
+	 * code surrounding the replay cache... */
+
+	if (!grab_server_mutex("replay cache mutex")) {
+		DEBUG(1,("ads_verify_ticket: unable to protect replay cache with mutex.\n"));
+		sret = NT_STATUS_LOGON_FAILURE;
+		goto out;
+	}
+
+	got_replay_mutex = True;
+
+	/* We need to setup a auth context with each possible encoding type in turn. */
+	for (i=0;enctypes[i];i++) {
+		if (!(key = (krb5_keyblock *)malloc(sizeof(*key)))) {
+			sret = NT_STATUS_NO_MEMORY;
+			goto out;
+		}
+	
+		if (create_kerberos_key_from_string(context, host_princ, &password, key, enctypes[i])) {
+			continue;
+		}
+
+		krb5_auth_con_setuseruserkey(context, auth_context, key);
+
+		krb5_free_keyblock(context, key);
+
+		packet.length = ticket->length;
+		packet.data = (krb5_pointer)ticket->data;
+
+		if (!(ret = krb5_rd_req(context, &auth_context, &packet, 
+					NULL,
+					NULL, NULL, &tkt))) {
+			DEBUG(10,("ads_verify_ticket: enc type [%u] decrypted message !\n",
+				(unsigned int)enctypes[i] ));
+			auth_ok = True;
+			break;
+		}
+	
+		DEBUG((ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
+				("ads_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
+				(unsigned int)enctypes[i], error_message(ret)));
+	}
+
+	release_server_mutex();
+	got_replay_mutex = False;
+
+	if (!auth_ok) {
+		DEBUG(3,("ads_verify_ticket: krb5_rd_req with auth failed (%s)\n", 
+			 error_message(ret)));
+		sret = NT_STATUS_LOGON_FAILURE;
+		goto out;
+	}
+
+	ret = krb5_mk_rep(context, auth_context, &packet);
+	if (ret) {
+		DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
+			error_message(ret)));
+		sret = NT_STATUS_LOGON_FAILURE;
+		goto out;
+	}
+
+	*ap_rep = data_blob(packet.data, packet.length);
+	free(packet.data);
+
+	get_krb5_smb_session_key(context, auth_context, session_key, True);
+	dump_data_pw("SMB session key (from ticket)\n", session_key->data, session_key->length);
+
+#if 0
+	file_save("/tmp/ticket.dat", ticket->data, ticket->length);
+#endif
+
+	/* auth_data is the PAC */
+	get_auth_data_from_tkt(auth_data, tkt);
+
+#if 0
+	if (tkt->enc_part2) {
+		file_save("/tmp/authdata.dat",
+			  tkt->enc_part2->authorization_data[0]->contents,
+			  tkt->enc_part2->authorization_data[0]->length);
+	}
+#endif
+
+	if ((ret = krb5_unparse_name(context, get_principal_from_tkt(tkt),
+				     principal))) {
+		DEBUG(3,("ads_verify_ticket: krb5_unparse_name failed (%s)\n", 
+			 error_message(ret)));
+		sret = NT_STATUS_LOGON_FAILURE;
+		goto out;
+	}
+
+	sret = NT_STATUS_OK;
+
+ out:
+
+	if (got_replay_mutex)
+		release_server_mutex();
+
+	if (!NT_STATUS_IS_OK(sret))
+		data_blob_free(auth_data);
+
+	if (!NT_STATUS_IS_OK(sret))
+		data_blob_free(ap_rep);
+
+	if (free_host_princ)
+		krb5_free_principal(context, host_princ);
+
+	if (tkt != NULL)
+		krb5_free_ticket(context, tkt);
+	free_kerberos_etypes(context, enctypes);
+	SAFE_FREE(password_s);
+	SAFE_FREE(host_princ_s);
+
+	if (auth_context)
+		krb5_auth_con_free(context, auth_context);
+
+	if (context)
+		krb5_free_context(context);
+
+	return sret;
+}
+
+#endif /* HAVE_KRB5 */