/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
* Authors: Jeffrey Stedfast <fejj@ximian.com>
*
* Copyright 2001 Ximian, Inc. (www.ximian.com)
*
* 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., 59 Temple Street #330, Boston, MA 02111-1307, USA.
*
*/
#include <config.h>
#ifdef HAVE_KRB4
#include <krb.h>
/* MIT krb4 des.h #defines _. Sigh. We don't need it. #undef it here
* so we get the gettexty _ definition later.
*/
#undef _
#endif
#include "camel-sasl-kerberos4.h"
#include "camel-mime-utils.h"
#include <string.h>
#define KERBEROS_V4_PROTECTION_NONE 1
#define KERBEROS_V4_PROTECTION_INTEGRITY 2
#define KERBEROS_V4_PROTECTION_PRIVACY 4
static CamelSaslClass *parent_class = NULL;
/* Returns the class for a CamelSaslKerberos4 */
#define CSK4_CLASS(so) CAMEL_SASL_KERBEROS4_CLASS (CAMEL_OBJECT_GET_CLASS (so))
#ifdef HAVE_KRB4
static GByteArray *krb4_challenge (CamelSasl *sasl, const char *token, CamelException *ex);
#endif
enum {
STATE_NONCE,
STATE_NONCE_PLUS_ONE,
STATE_FINAL
};
struct _CamelSaslKerberos4Private {
int state;
guint32 nonce_n;
guint32 nonce_h;
guint32 plus1;
#ifdef HAVE_KRB4
KTEXT_ST authenticator;
CREDENTIALS credentials;
des_cblock session;
des_key_schedule schedule;
#endif /* HAVE_KRB4 */
};
static void
camel_sasl_kerberos4_class_init (CamelSaslKerberos4Class *camel_sasl_kerberos4_class)
{
#ifdef HAVE_KRB4
CamelSaslClass *camel_sasl_class = CAMEL_SASL_CLASS (camel_sasl_kerberos4_class);
#endif
parent_class = CAMEL_SASL_CLASS (camel_type_get_global_classfuncs (camel_sasl_get_type ()));
/* virtual method overload */
#ifdef HAVE_KRB4
camel_sasl_class->challenge = krb4_challenge;
#endif
}
static void
camel_sasl_kerberos4_init (gpointer object, gpointer klass)
{
CamelSaslKerberos4 *sasl_krb4 = CAMEL_SASL_KERBEROS4 (object);
sasl_krb4->priv = g_new0 (struct _CamelSaslKerberos4Private, 1);
}
static void
camel_sasl_kerberos4_finalize (CamelObject *object)
{
CamelSaslKerberos4 *sasl = CAMEL_SASL_KERBEROS4 (object);
g_free (sasl->protocol);
g_free (sasl->username);
g_free (sasl->priv);
}
CamelType
camel_sasl_kerberos4_get_type (void)
{
static CamelType type = CAMEL_INVALID_TYPE;
if (type == CAMEL_INVALID_TYPE) {
type = camel_type_register (camel_sasl_get_type (),
"CamelSaslKerberos4",
sizeof (CamelSaslKerberos4),
sizeof (CamelSaslKerberos4Class),
(CamelObjectClassInitFunc) camel_sasl_kerberos4_class_init,
NULL,
(CamelObjectInitFunc) camel_sasl_kerberos4_init,
(CamelObjectFinalizeFunc) camel_sasl_kerberos4_finalize);
}
return type;
}
CamelSasl *
camel_sasl_kerberos4_new (const char *protocol, const char *username, struct hostent *host)
{
CamelSaslKerberos4 *sasl_krb4;
if (!protocol) return NULL;
if (!username) return NULL;
if (!host) return NULL;
#ifdef HAVE_KRB4
sasl_krb4 = CAMEL_SASL_KERBEROS4 (camel_object_new (camel_sasl_kerberos4_get_type ()));
sasl_krb4->protocol = g_strdup (protocol);
g_strdown (sasl_krb4->protocol);
sasl_krb4->username = g_strdup (username);
sasl_krb4->host = host;
return CAMEL_SASL (sasl_krb4);
#else
return NULL;
#endif /* HAVE_KRB4 */
}
#ifdef HAVE_KRB4
static GByteArray *
krb4_challenge (CamelSasl *sasl, const char *token, CamelException *ex)
{
CamelSaslKerberos4 *sasl_krb4 = CAMEL_SASL_KERBEROS4 (sasl);
struct _CamelSaslKerberos4Private *priv = sasl_krb4->priv;
char *buf = NULL, *data = NULL;
GByteArray *ret = NULL;
char *inst, *realm;
struct hostent *h;
int status, len;
KTEXT_ST authenticator;
CREDENTIALS credentials;
des_cblock session;
des_key_schedule schedule;
if (token)
data = g_strdup (token);
else
goto fail;
switch (priv->state) {
case STATE_NONCE:
if (strlen (data) != 8 || base64_decode_simple (data, 8) != 4)
goto break_and_lose;
memcpy (&priv->nonce_n, data, 4);
priv->nonce_h = ntohl (priv->nonce_n);
/* Our response is an authenticator including that number. */
h = sasl_krb4->host;
inst = g_strndup (h->h_name, strcspn (h->h_name, "."));
g_strdown (inst);
realm = g_strdup (krb_realmofhost (h->h_name));
status = krb_mk_req (&authenticator, sasl_krb4->protocol, inst, realm, priv->nonce_h);
if (status == KSUCCESS) {
status = krb_get_cred (sasl_krb4->protocol, inst, realm, &credentials);
memcpy (session, credentials.session, sizeof (session));
memset (&credentials, 0, sizeof (credentials));
}
g_free (inst);
g_free (realm);
if (status != KSUCCESS) {
camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
_("Could not get Kerberos ticket:\n%s"),
krb_err_txt[status]);
goto break_and_lose;
}
des_key_sched (&session, schedule);
buf = base64_encode_simple (authenticator.dat, authenticator.length);
break;
case STATE_NONCE_PLUS_ONE:
len = strlen (data);
base64_decode_simple (data, len);
/* This one is encrypted. */
des_ecb_encrypt ((des_cblock *)data, (des_cblock *)data, schedule, 0);
/* Check that the returned value is the original nonce plus one. */
memcpy (&priv->plus1, data, 4);
if (ntohl (priv->plus1) != priv->nonce_h + 1)
goto lose;
/* "the fifth octet contain[s] a bit-mask specifying the
* protection mechanisms supported by the server"
*/
if (!(data[4] & KERBEROS_V4_PROTECTION_NONE)) {
g_warning ("Server does not support `no protection' :-(");
goto break_and_lose;
}
len = strlen (sasl_krb4->username) + 9;
len += 8 - len % 8;
data = g_malloc0 (len);
memcpy (data, &priv->nonce_n, 4);
data[4] = KERBEROS_V4_PROTECTION_NONE;
data[5] = data[6] = data[7] = 0;
strcpy (data + 8, sasl_krb4->username);
des_pcbc_encrypt ((void *)data, (void *)data, len,
schedule, &session, 1);
memset (&session, 0, sizeof (session));
buf = base64_encode_simple (data, len);
break;
case STATE_FINAL:
sasl->authenticated = TRUE;
break;
default:
break;
}
g_free (data);
priv->state++;
if (buf) {
ret = g_byte_array_new ();
g_byte_array_append (ret, buf, strlen (buf));
g_free (buf);
}
return ret;
break_and_lose:
/* Get the server out of "waiting for continuation data" mode. */
g_free (data);
ret = g_byte_array_new ();
g_byte_array_append (ret, "*", 1);
return ret;
lose:
memset (&session, 0, sizeof (session));
if (!camel_exception_is_set (ex)) {
camel_exception_set (ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
_("Bad authentication response from server."));
}
fail:
g_free (data);
return NULL;
}
#endif HAVE_KRB4
