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/*
* Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Kungliga Tekniska
* Högskolan and its contributors.
*
* 4. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <popper.h>
#include <base64.h>
RCSID("$Id: pop_auth.c,v 1.2 2000/04/12 15:37:45 assar Exp $");
#ifdef KRB4
enum {
NO_PROT = 1,
INT_PROT = 2,
PRIV_PROT = 4
};
static int
auth_krb4(POP *p)
{
int ret;
des_cblock key;
u_int32_t nonce, nonce_reply;
u_int32_t max_client_packet;
int protocols = NO_PROT | INT_PROT | PRIV_PROT;
char data[8];
int len;
char *s;
char instance[INST_SZ];
KTEXT_ST authent;
des_key_schedule schedule;
struct passwd *pw;
/* S -> C: 32 bit nonce in MSB base64 */
des_new_random_key(&key);
nonce = (key[0] | (key[1] << 8) | (key[2] << 16) | (key[3] << 24)
| key[4] | (key[5] << 8) | (key[6] << 16) | (key[7] << 24));
krb_put_int(nonce, data, 4, 8);
len = base64_encode(data, 4, &s);
pop_msg(p, POP_CONTINUE, "%s", s);
free(s);
/* C -> S: ticket and authenticator */
ret = sch_readline(p->input, &s);
if (ret <= 0 || strcmp (s, "*") == 0)
return pop_msg(p, POP_FAILURE,
"authentication aborted by client");
len = strlen(s);
if (len > sizeof(authent.dat)) {
return pop_msg(p, POP_FAILURE, "data packet too long");
}
authent.length = base64_decode(s, authent.dat);
k_getsockinst (0, instance, sizeof(instance));
ret = krb_rd_req(&authent, "pop", instance,
p->in_addr.sin_addr.s_addr,
&p->kdata, NULL);
if (ret != 0) {
return pop_msg(p, POP_FAILURE, "rd_req: %s",
krb_get_err_text(ret));
}
if (p->kdata.checksum != nonce) {
return pop_msg(p, POP_FAILURE, "data stream modified");
}
/* S -> C: nonce + 1 | bit | max segment */
krb_put_int(nonce + 1, data, 4, 7);
data[4] = protocols;
krb_put_int(1024, data + 5, 3, 3); /* XXX */
des_key_sched(&p->kdata.session, schedule);
des_pcbc_encrypt((des_cblock*)data,
(des_cblock*)data, 8,
schedule,
&p->kdata.session,
DES_ENCRYPT);
len = base64_encode(data, 8, &s);
pop_msg(p, POP_CONTINUE, "%s", s);
free(s);
/* C -> S: nonce | bit | max segment | username */
ret = sch_readline(p->input, &s);
if (ret <= 0 || strcmp (s, "*") == 0)
return pop_msg(p, POP_FAILURE,
"authentication aborted");
len = strlen(s);
if (len > sizeof(authent.dat)) {
return pop_msg(p, POP_FAILURE, "data packet too long");
}
authent.length = base64_decode(s, authent.dat);
if (authent.length % 8 != 0) {
return pop_msg(p, POP_FAILURE, "reply is not a multiple of 8 bytes");
}
des_key_sched(&p->kdata.session, schedule);
des_pcbc_encrypt((des_cblock*)authent.dat,
(des_cblock*)authent.dat,
authent.length,
schedule,
&p->kdata.session,
DES_DECRYPT);
krb_get_int(authent.dat, &nonce_reply, 4, 0);
if (nonce_reply != nonce) {
return pop_msg(p, POP_FAILURE, "data stream modified");
}
protocols &= authent.dat[4];
krb_get_int(authent.dat + 5, &max_client_packet, 3, 0);
if(authent.dat[authent.length - 1] != '\0') {
return pop_msg(p, POP_FAILURE, "bad format of username");
}
strncpy (p->user, authent.dat + 8, sizeof(p->user));
pw = k_getpwnam(p->user);
if (pw == NULL) {
return (pop_msg(p,POP_FAILURE,
"Password supplied for \"%s\" is incorrect.",
p->user));
}
if (kuserok(&p->kdata, p->user)) {
pop_log(p, POP_PRIORITY,
"%s: (%s.%s@%s) tried to retrieve mail for %s.",
p->client, p->kdata.pname, p->kdata.pinst,
p->kdata.prealm, p->user);
return(pop_msg(p,POP_FAILURE,
"Popping not authorized"));
}
pop_log(p, POP_INFO, "%s: %s.%s@%s -> %s",
p->ipaddr,
p->kdata.pname, p->kdata.pinst, p->kdata.prealm,
p->user);
ret = pop_login(p, pw);
if (protocols & PRIV_PROT)
;
else if (protocols & INT_PROT)
;
else
;
return ret;
}
#endif /* KRB4 */
#ifdef KRB5
static int
auth_gssapi(POP *p)
{
}
#endif /* KRB5 */
/*
* auth: RFC1734
*/
static struct {
const char *name;
int (*func)(POP *);
} methods[] = {
#ifdef KRB4
{"KERBEROS_V4", auth_krb4},
#endif
#ifdef KRB5
{"GSSAPI", auth_gssapi},
#endif
{NULL, NULL}
};
int
pop_auth (POP *p)
{
int i;
for (i = 0; methods[i].name != NULL; ++i)
if (strcasecmp(p->pop_parm[1], methods[i].name) == 0)
return (*methods[i].func)(p);
return pop_msg(p, POP_FAILURE,
"Authentication method %s unknown", p->pop_parm[1]);
}
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