/*
* Copyright (c) 1997 - 2000 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 "krb5_locl.h"
RCSID("$Id: send_to_kdc.c,v 1.36 2000/01/06 07:59:11 assar Exp $");
/*
* send the data in `req' on the socket `fd' (which is datagram iff udp)
* waiting `tmout' for a reply and returning the reply in `rep'.
* iff limit read up to this many bytes
* returns 0 and data in `rep' if succesful, otherwise -1
*/
static int
recv_loop (int fd,
time_t tmout,
int udp,
size_t limit,
krb5_data *rep)
{
fd_set fdset;
struct timeval timeout;
int ret;
int nbytes;
krb5_data_zero(rep);
do {
FD_ZERO(&fdset);
FD_SET(fd, &fdset);
timeout.tv_sec = tmout;
timeout.tv_usec = 0;
ret = select (fd + 1, &fdset, NULL, NULL, &timeout);
if (ret < 0) {
if (errno == EINTR)
continue;
return -1;
} else if (ret == 0) {
return 0;
} else {
void *tmp;
if (ioctl (fd, FIONREAD, &nbytes) < 0) {
krb5_data_free (rep);
return -1;
}
if(nbytes == 0)
return 0;
if (limit)
nbytes = min(nbytes, limit - rep->length);
tmp = realloc (rep->data, rep->length + nbytes);
if (tmp == NULL) {
krb5_data_free (rep);
return -1;
}
rep->data = tmp;
ret = recv (fd, (char*)tmp + rep->length, nbytes, 0);
if (ret < 0) {
krb5_data_free (rep);
return -1;
}
rep->length += ret;
}
} while(!udp && (limit == 0 || rep->length < limit));
return 0;
}
/*
* Send kerberos requests and receive a reply on a udp or any other kind
* of a datagram socket. See `recv_loop'.
*/
static int
send_and_recv_udp(int fd,
time_t tmout,
const krb5_data *req,
krb5_data *rep)
{
if (send (fd, req->data, req->length, 0) < 0)
return -1;
return recv_loop(fd, tmout, 1, 0, rep);
}
/*
* `send_and_recv' for a TCP (or any other stream) socket.
* Since there are no record limits on a stream socket the protocol here
* is to prepend the request with 4 bytes of its length and the reply
* is similarly encoded.
*/
static int
send_and_recv_tcp(int fd,
time_t tmout,
const krb5_data *req,
krb5_data *rep)
{
unsigned char len[4];
unsigned long rep_len;
krb5_data len_data;
_krb5_put_int(len, req->length, 4);
if(net_write(fd, len, sizeof(len)) < 0)
return -1;
if(net_write(fd, req->data, req->length) < 0)
return -1;
if (recv_loop (fd, tmout, 0, 4, &len_data) < 0)
return -1;
if (len_data.length != 4) {
krb5_data_free (&len_data);
return -1;
}
_krb5_get_int(len_data.data, &rep_len, 4);
krb5_data_free (&len_data);
if (recv_loop (fd, tmout, 0, rep_len, rep) < 0)
return -1;
if(rep->length != rep_len) {
krb5_data_free (rep);
return -1;
}
return 0;
}
/*
* `send_and_recv' tailored for the HTTP protocol.
*/
static int
send_and_recv_http(int fd,
time_t tmout,
const char *prefix,
const krb5_data *req,
krb5_data *rep)
{
char *request;
char *str;
int ret;
int len = base64_encode(req->data, req->length, &str);
if(len < 0)
return -1;
asprintf(&request, "GET %s%s HTTP/1.0\r\n\r\n", prefix, str);
free(str);
if (request == NULL)
return -1;
ret = net_write (fd, request, strlen(request));
free (request);
if (ret < 0)
return ret;
ret = recv_loop(fd, tmout, 0, 0, rep);
if(ret)
return ret;
{
unsigned long rep_len;
char *s, *p;
s = realloc(rep->data, rep->length + 1);
if (s == NULL) {
krb5_data_free (rep);
return -1;
}
s[rep->length] = 0;
p = strstr(s, "\r\n\r\n");
if(p == NULL) {
free(s);
return -1;
}
p += 4;
rep->data = s;
rep->length -= p - s;
if(rep->length < 4) { /* remove length */
free(s);
return -1;
}
rep->length -= 4;
_krb5_get_int(p, &rep_len, 4);
if (rep_len != rep->length) {
free(s);
return -1;
}
memmove(rep->data, p + 4, rep->length);
}
return 0;
}
static int
init_port(const char *s, int fallback)
{
if (s) {
int tmp;
sscanf (s, "%d", &tmp);
return htons(tmp);
} else
return fallback;
}
/*
* Return 0 if succesful, otherwise 1
*/
static int
send_via_proxy (krb5_context context,
const char *hostname,
const krb5_data *send,
krb5_data *receive)
{
char *proxy = strdup(context->http_proxy);
char *prefix;
char *colon;
struct addrinfo hints;
struct addrinfo *ai, *a;
int ret;
int s;
char portstr[NI_MAXSERV];
colon = strchr(proxy, ':');
if(colon != NULL)
*colon++ = '\0';
memset (&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
snprintf (portstr, sizeof(portstr), "%d",
ntohs(init_port (colon, htons(80))));
ret = getaddrinfo (proxy, portstr, NULL, &ai);
free (proxy);
if (ret)
return ret;
for (a = ai; a != NULL; a = a->ai_next) {
s = socket (a->ai_family, a->ai_socktype, a->ai_protocol);
if (s < 0)
continue;
if (connect (s, a->ai_addr, a->ai_addrlen) < 0) {
close (s);
continue;
}
break;
}
if (a == NULL) {
freeaddrinfo (ai);
return 1;
}
freeaddrinfo (ai);
asprintf(&prefix, "http://%s/", hostname);
if(prefix == NULL) {
close(s);
return 1;
}
ret = send_and_recv_http(s, context->kdc_timeout,
prefix, send, receive);
close (s);
free(prefix);
if(ret == 0 && receive->length != 0)
return 0;
return 1;
}
/*
* Send the data `send' to one KDC in `realm' and get back the reply
* in `receive'.
*/
krb5_error_code
krb5_sendto_kdc (krb5_context context,
const krb5_data *send,
const krb5_realm *realm,
krb5_data *receive)
{
krb5_error_code ret;
char **hostlist, **hp, *p;
int fd;
int port;
int i;
port = krb5_getportbyname (context, "kerberos", "udp", 88);
if (context->use_admin_kdc)
ret = krb5_get_krb_admin_hst (context, realm, &hostlist);
else
ret = krb5_get_krbhst (context, realm, &hostlist);
if (ret)
return ret;
for (i = 0; i < context->max_retries; ++i)
for (hp = hostlist; (p = *hp); ++hp) {
char *colon;
int http_flag = 0;
int tcp_flag = 0;
struct addrinfo *ai, *a;
struct addrinfo hints;
char portstr[NI_MAXSERV];
if(strncmp(p, "http://", 7) == 0){
p += 7;
http_flag = 1;
port = htons(80);
} else if(strncmp(p, "http/", 5) == 0) {
p += 5;
http_flag = 1;
port = htons(80);
}else if(strncmp(p, "tcp/", 4) == 0){
p += 4;
tcp_flag = 1;
} else if(strncmp(p, "udp/", 4) == 0) {
p += 4;
}
if(http_flag && context->http_proxy) {
if (send_via_proxy (context, p, send, receive))
continue;
else
goto out;
}
colon = strchr (p, ':');
if (colon)
*colon++ = '\0';
memset (&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
if (tcp_flag || http_flag)
hints.ai_socktype = SOCK_STREAM;
else
hints.ai_socktype = SOCK_DGRAM;
snprintf (portstr, sizeof(portstr), "%d",
ntohs(init_port (colon, port)));
ret = getaddrinfo (p, portstr, &hints, &ai);
if (ret)
continue;
for (a = ai; a != NULL; a = a->ai_next) {
fd = socket (a->ai_family, a->ai_socktype, a->ai_protocol);
if (fd < 0)
continue;
if (connect (fd, a->ai_addr, a->ai_addrlen) < 0) {
close (fd);
continue;
}
break;
}
if (a == NULL) {
freeaddrinfo (ai);
continue;
}
freeaddrinfo (ai);
if(http_flag)
ret = send_and_recv_http(fd, context->kdc_timeout,
"", send, receive);
else if(tcp_flag)
ret = send_and_recv_tcp (fd, context->kdc_timeout,
send, receive);
else
ret = send_and_recv_udp (fd, context->kdc_timeout,
send, receive);
close (fd);
if(ret == 0 && receive->length != 0)
goto out;
}
ret = KRB5_KDC_UNREACH;
out:
krb5_free_krbhst (context, hostlist);
return ret;
}
