curl/lib/krb4.c
2001-01-25 12:19:36 +00:00

501 lines
13 KiB
C

/* modified by Martin Hedenfalk <mhe@stacken.kth.se> for use in Curl
* last modified 2000-09-18
*/
/*
* Copyright (c) 1995, 1996, 1997, 1998, 1999 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. 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 "setup.h"
#ifdef KRB4
#include "security.h"
#include "base64.h"
#include <stdlib.h>
#include <netdb.h>
#include <syslog.h>
#include <string.h>
#include <krb.h>
#include "ftp.h"
#include "sendf.h"
/* The last #include file should be: */
#ifdef MALLOCDEBUG
#include "memdebug.h"
#endif
#ifdef FTP_SERVER
#define LOCAL_ADDR ctrl_addr
#define REMOTE_ADDR his_addr
#else
/*#define LOCAL_ADDR myctladdr***/
/*#define REMOTE_ADDR hisctladdr***/
#endif
/*extern struct sockaddr *LOCAL_ADDR, *REMOTE_ADDR;***/
#define LOCAL_ADDR (&local_addr)
#define REMOTE_ADDR (&conn->serv_addr)
#define myctladdr LOCAL_ADDR
#define hisctladdr REMOTE_ADDR
static struct sockaddr_in local_addr;
struct krb4_data {
des_cblock key;
des_key_schedule schedule;
char name[ANAME_SZ];
char instance[INST_SZ];
char realm[REALM_SZ];
};
#ifndef HAVE_STRLCPY
size_t
strlcpy (char *dst, const char *src, size_t dst_sz)
{
size_t n;
char *p;
for (p = dst, n = 0;
n + 1 < dst_sz && *src != '\0';
++p, ++src, ++n)
*p = *src;
*p = '\0';
if (*src == '\0')
return n;
else
return n + strlen (src);
}
#else
size_t strlcpy (char *dst, const char *src, size_t dst_sz);
#endif
static int
krb4_check_prot(void *app_data, int level)
{
if(level == prot_confidential)
return -1;
return 0;
}
static int
krb4_decode(void *app_data, void *buf, int len, int level,
struct connectdata *conn)
{
MSG_DAT m;
int e;
struct krb4_data *d = app_data;
if(level == prot_safe)
e = krb_rd_safe(buf, len, &d->key,
(struct sockaddr_in *)REMOTE_ADDR,
(struct sockaddr_in *)LOCAL_ADDR, &m);
else
e = krb_rd_priv(buf, len, d->schedule, &d->key,
(struct sockaddr_in *)REMOTE_ADDR,
(struct sockaddr_in *)LOCAL_ADDR, &m);
if(e){
syslog(LOG_ERR, "krb4_decode: %s", krb_get_err_text(e));
return -1;
}
memmove(buf, m.app_data, m.app_length);
return m.app_length;
}
static int
krb4_overhead(void *app_data, int level, int len)
{
return 31;
}
static int
krb4_encode(void *app_data, void *from, int length, int level, void **to,
struct connectdata *conn)
{
struct krb4_data *d = app_data;
*to = malloc(length + 31);
if(level == prot_safe)
return krb_mk_safe(from, *to, length, &d->key,
(struct sockaddr_in *)LOCAL_ADDR,
(struct sockaddr_in *)REMOTE_ADDR);
else if(level == prot_private)
return krb_mk_priv(from, *to, length, d->schedule, &d->key,
(struct sockaddr_in *)LOCAL_ADDR,
(struct sockaddr_in *)REMOTE_ADDR);
else
return -1;
}
#ifdef FTP_SERVER
static int
krb4_adat(void *app_data, void *buf, size_t len)
{
KTEXT_ST tkt;
AUTH_DAT auth_dat;
char *p;
int kerror;
u_int32_t cs;
char msg[35]; /* size of encrypted block */
int tmp_len;
struct krb4_data *d = app_data;
char inst[INST_SZ];
struct sockaddr_in *his_addr_sin = (struct sockaddr_in *)his_addr;
memcpy(tkt.dat, buf, len);
tkt.length = len;
k_getsockinst(0, inst, sizeof(inst));
kerror = krb_rd_req(&tkt, "ftp", inst,
his_addr_sin->sin_addr.s_addr, &auth_dat, "");
if(kerror == RD_AP_UNDEC){
k_getsockinst(0, inst, sizeof(inst));
kerror = krb_rd_req(&tkt, "rcmd", inst,
his_addr_sin->sin_addr.s_addr, &auth_dat, "");
}
if(kerror){
reply(535, "Error reading request: %s.", krb_get_err_text(kerror));
return -1;
}
memcpy(d->key, auth_dat.session, sizeof(d->key));
des_set_key(&d->key, d->schedule);
strlcpy(d->name, auth_dat.pname, sizeof(d->name));
strlcpy(d->instance, auth_dat.pinst, sizeof(d->instance));
strlcpy(d->realm, auth_dat.prealm, sizeof(d->instance));
cs = auth_dat.checksum + 1;
{
unsigned char tmp[4];
KRB_PUT_INT(cs, tmp, 4, sizeof(tmp));
tmp_len = krb_mk_safe(tmp, msg, 4, &d->key,
(struct sockaddr_in *)LOCAL_ADDR,
(struct sockaddr_in *)REMOTE_ADDR);
}
if(tmp_len < 0){
reply(535, "Error creating reply: %s.", strerror(errno));
return -1;
}
len = tmp_len;
if(base64_encode(msg, len, &p) < 0) {
reply(535, "Out of memory base64-encoding.");
return -1;
}
reply(235, "ADAT=%s", p);
sec_complete = 1;
free(p);
return 0;
}
static int
krb4_userok(void *app_data, char *user)
{
struct krb4_data *d = app_data;
return krb_kuserok(d->name, d->instance, d->realm, user);
}
struct sec_server_mech krb4_server_mech = {
"KERBEROS_V4",
sizeof(struct krb4_data),
NULL, /* init */
NULL, /* end */
krb4_check_prot,
krb4_overhead,
krb4_encode,
krb4_decode,
/* */
NULL,
krb4_adat,
NULL, /* pbsz */
NULL, /* ccc */
krb4_userok
};
#else /* FTP_SERVER */
static int
mk_auth(struct krb4_data *d, KTEXT adat,
char *service, char *host, int checksum)
{
int ret;
CREDENTIALS cred;
char sname[SNAME_SZ], inst[INST_SZ], realm[REALM_SZ];
strlcpy(sname, service, sizeof(sname));
strlcpy(inst, krb_get_phost(host), sizeof(inst));
strlcpy(realm, krb_realmofhost(host), sizeof(realm));
ret = krb_mk_req(adat, sname, inst, realm, checksum);
if(ret)
return ret;
strlcpy(sname, service, sizeof(sname));
strlcpy(inst, krb_get_phost(host), sizeof(inst));
strlcpy(realm, krb_realmofhost(host), sizeof(realm));
ret = krb_get_cred(sname, inst, realm, &cred);
memmove(&d->key, &cred.session, sizeof(des_cblock));
des_key_sched(&d->key, d->schedule);
memset(&cred, 0, sizeof(cred));
return ret;
}
static int
krb4_auth(void *app_data, struct connectdata *conn)
{
int ret;
char *p;
int len;
KTEXT_ST adat;
MSG_DAT msg_data;
int checksum;
u_int32_t cs;
struct krb4_data *d = app_data;
struct sockaddr_in *localaddr = (struct sockaddr_in *)LOCAL_ADDR;
#if 0
struct sockaddr_in *remoteaddr = (struct sockaddr_in *)REMOTE_ADDR;
#endif
char *host = conn->hp->h_name;
size_t nread;
int l = sizeof(local_addr);
if(getsockname(conn->data->firstsocket,
(struct sockaddr *)LOCAL_ADDR, &l) < 0)
perror("getsockname()");
checksum = getpid();
ret = mk_auth(d, &adat, "ftp", host, checksum);
if(ret == KDC_PR_UNKNOWN)
ret = mk_auth(d, &adat, "rcmd", host, checksum);
if(ret){
printf("%s\n", krb_get_err_text(ret));
return AUTH_CONTINUE;
}
#ifdef HAVE_KRB_GET_OUR_IP_FOR_REALM
if (krb_get_config_bool("nat_in_use")) {
struct in_addr natAddr;
if (krb_get_our_ip_for_realm(krb_realmofhost(host),
&natAddr) != KSUCCESS
&& krb_get_our_ip_for_realm(NULL, &natAddr) != KSUCCESS)
printf("Can't get address for realm %s\n",
krb_realmofhost(host));
else {
if (natAddr.s_addr != localaddr->sin_addr.s_addr) {
printf("Using NAT IP address (%s) for kerberos 4\n",
(char *)inet_ntoa(natAddr));
localaddr->sin_addr = natAddr;
/*
* This not the best place to do this, but it
* is here we know that (probably) NAT is in
* use!
*/
/*passivemode = 1;***/
/*printf("Setting: Passive mode on.\n");***/
}
}
}
#endif
/*printf("Local address is %s\n", inet_ntoa(localaddr->sin_addr));***/
/*printf("Remote address is %s\n", inet_ntoa(remoteaddr->sin_addr));***/
if(Curl_base64_encode(adat.dat, adat.length, &p) < 0) {
printf("Out of memory base64-encoding.\n");
return AUTH_CONTINUE;
}
/*ret = command("ADAT %s", p)*/
Curl_ftpsendf(conn->data->firstsocket, conn, "ADAT %s", p);
/* wait for feedback */
nread = Curl_GetFTPResponse(conn->data->firstsocket,
conn->data->buffer, conn, NULL);
if(nread < 0)
return /*CURLE_OPERATION_TIMEOUTED*/-1;
free(p);
if(/*ret != COMPLETE*/conn->data->buffer[0] != '2'){
printf("Server didn't accept auth data.\n");
return AUTH_ERROR;
}
p = strstr(/*reply_string*/conn->data->buffer, "ADAT=");
if(!p){
printf("Remote host didn't send adat reply.\n");
return AUTH_ERROR;
}
p += 5;
len = Curl_base64_decode(p, adat.dat);
if(len < 0){
printf("Failed to decode base64 from server.\n");
return AUTH_ERROR;
}
adat.length = len;
ret = krb_rd_safe(adat.dat, adat.length, &d->key,
(struct sockaddr_in *)hisctladdr,
(struct sockaddr_in *)myctladdr, &msg_data);
if(ret){
printf("Error reading reply from server: %s.\n",
krb_get_err_text(ret));
return AUTH_ERROR;
}
krb_get_int(msg_data.app_data, &cs, 4, 0);
if(cs - checksum != 1){
printf("Bad checksum returned from server.\n");
return AUTH_ERROR;
}
return AUTH_OK;
}
struct sec_client_mech krb4_client_mech = {
"KERBEROS_V4",
sizeof(struct krb4_data),
NULL, /* init */
krb4_auth,
NULL, /* end */
krb4_check_prot,
krb4_overhead,
krb4_encode,
krb4_decode
};
#endif /* FTP_SERVER */
void krb_kauth(struct connectdata *conn)
{
des_cblock key;
des_key_schedule schedule;
KTEXT_ST tkt, tktcopy;
char *name;
char *p;
char passwd[100];
int tmp;
size_t nread;
int save;
save = set_command_prot(conn, prot_private);
/*ret = command("SITE KAUTH %s", name);***/
Curl_ftpsendf(conn->data->firstsocket, conn,
"SITE KAUTH %s", conn->data->user);
/* wait for feedback */
nread = Curl_GetFTPResponse(conn->data->firstsocket, conn->data->buffer,
conn, NULL);
if(nread < 0)
return /*CURLE_OPERATION_TIMEOUTED*/;
if(/*ret != CONTINUE*/conn->data->buffer[0] != '3'){
set_command_prot(conn, save);
/*code = -1;***/
return;
}
p = strstr(/*reply_string***/conn->data->buffer, "T=");
if(!p){
printf("Bad reply from server.\n");
set_command_prot(conn, save);
/*code = -1;***/
return;
}
p += 2;
tmp = Curl_base64_decode(p, &tkt.dat);
if(tmp < 0){
printf("Failed to decode base64 in reply.\n");
set_command_prot(conn, save);
/*code = -1;***/
return;
}
tkt.length = tmp;
tktcopy.length = tkt.length;
p = strstr(/*reply_string***/conn->data->buffer, "P=");
if(!p){
printf("Bad reply from server.\n");
set_command_prot(conn, save);
/*code = -1;***/
return;
}
name = p + 2;
for(; *p && *p != ' ' && *p != '\r' && *p != '\n'; p++);
*p = 0;
#if 0
snprintf(buf, sizeof(buf), "Password for %s:", name);
if (des_read_pw_string (passwd, sizeof(passwd)-1, buf, 0))
*passwd = '\0';
des_string_to_key (passwd, &key);
#else
des_string_to_key (conn->data->passwd, &key);
#endif
des_key_sched(&key, schedule);
des_pcbc_encrypt((des_cblock*)tkt.dat, (des_cblock*)tktcopy.dat,
tkt.length,
schedule, &key, DES_DECRYPT);
if (strcmp ((char*)tktcopy.dat + 8,
KRB_TICKET_GRANTING_TICKET) != 0) {
afs_string_to_key (passwd,
krb_realmofhost(/*hostname***/conn->hp->h_name),
&key);
des_key_sched (&key, schedule);
des_pcbc_encrypt((des_cblock*)tkt.dat, (des_cblock*)tktcopy.dat,
tkt.length,
schedule, &key, DES_DECRYPT);
}
memset(key, 0, sizeof(key));
memset(schedule, 0, sizeof(schedule));
memset(passwd, 0, sizeof(passwd));
if(Curl_base64_encode(tktcopy.dat, tktcopy.length, &p) < 0) {
failf(conn->data, "Out of memory base64-encoding.\n");
set_command_prot(conn, save);
/*code = -1;***/
return;
}
memset (tktcopy.dat, 0, tktcopy.length);
/*ret = command("SITE KAUTH %s %s", name, p);***/
Curl_ftpsendf(conn->data->firstsocket, conn,
"SITE KAUTH %s %s", name, p);
/* wait for feedback */
nread = Curl_GetFTPResponse(conn->data->firstsocket, conn->data->buffer,
conn, NULL);
if(nread < 0)
return /*CURLE_OPERATION_TIMEOUTED*/;
free(p);
set_command_prot(conn, save);
}
#endif /* KRB4 */