b7aa600c41
I have worked hard to reduce diffs against the vendor branch. One notable change in that respect is that we no longer prefer DSA over RSA - the reasons for doing so went away years ago. This may cause some surprises, as ssh will warn about unknown host keys even for hosts whose keys haven't changed. MFC after: 6 weeks
377 lines
9.1 KiB
C
377 lines
9.1 KiB
C
/* $OpenBSD: auth-options.c,v 1.43 2008/06/10 23:06:19 djm Exp $ */
|
|
/*
|
|
* Author: Tatu Ylonen <ylo@cs.hut.fi>
|
|
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
|
|
* All rights reserved
|
|
* As far as I am concerned, the code I have written for this software
|
|
* can be used freely for any purpose. Any derived versions of this
|
|
* software must be clearly marked as such, and if the derived work is
|
|
* incompatible with the protocol description in the RFC file, it must be
|
|
* called by a name other than "ssh" or "Secure Shell".
|
|
*/
|
|
|
|
#include "includes.h"
|
|
|
|
#include <sys/types.h>
|
|
|
|
#include <netdb.h>
|
|
#include <pwd.h>
|
|
#include <string.h>
|
|
#include <stdio.h>
|
|
#include <stdarg.h>
|
|
|
|
#include "openbsd-compat/sys-queue.h"
|
|
#include "xmalloc.h"
|
|
#include "match.h"
|
|
#include "log.h"
|
|
#include "canohost.h"
|
|
#include "buffer.h"
|
|
#include "channels.h"
|
|
#include "auth-options.h"
|
|
#include "servconf.h"
|
|
#include "misc.h"
|
|
#include "key.h"
|
|
#include "hostfile.h"
|
|
#include "auth.h"
|
|
#ifdef GSSAPI
|
|
#include "ssh-gss.h"
|
|
#endif
|
|
#include "monitor_wrap.h"
|
|
|
|
/* Flags set authorized_keys flags */
|
|
int no_port_forwarding_flag = 0;
|
|
int no_agent_forwarding_flag = 0;
|
|
int no_x11_forwarding_flag = 0;
|
|
int no_pty_flag = 0;
|
|
int no_user_rc = 0;
|
|
|
|
/* "command=" option. */
|
|
char *forced_command = NULL;
|
|
|
|
/* "environment=" options. */
|
|
struct envstring *custom_environment = NULL;
|
|
|
|
/* "tunnel=" option. */
|
|
int forced_tun_device = -1;
|
|
|
|
extern ServerOptions options;
|
|
|
|
void
|
|
auth_clear_options(void)
|
|
{
|
|
no_agent_forwarding_flag = 0;
|
|
no_port_forwarding_flag = 0;
|
|
no_pty_flag = 0;
|
|
no_x11_forwarding_flag = 0;
|
|
no_user_rc = 0;
|
|
while (custom_environment) {
|
|
struct envstring *ce = custom_environment;
|
|
custom_environment = ce->next;
|
|
xfree(ce->s);
|
|
xfree(ce);
|
|
}
|
|
if (forced_command) {
|
|
xfree(forced_command);
|
|
forced_command = NULL;
|
|
}
|
|
forced_tun_device = -1;
|
|
channel_clear_permitted_opens();
|
|
auth_debug_reset();
|
|
}
|
|
|
|
/*
|
|
* return 1 if access is granted, 0 if not.
|
|
* side effect: sets key option flags
|
|
*/
|
|
int
|
|
auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
|
|
{
|
|
const char *cp;
|
|
int i;
|
|
|
|
/* reset options */
|
|
auth_clear_options();
|
|
|
|
if (!opts)
|
|
return 1;
|
|
|
|
while (*opts && *opts != ' ' && *opts != '\t') {
|
|
cp = "no-port-forwarding";
|
|
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
|
|
auth_debug_add("Port forwarding disabled.");
|
|
no_port_forwarding_flag = 1;
|
|
opts += strlen(cp);
|
|
goto next_option;
|
|
}
|
|
cp = "no-agent-forwarding";
|
|
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
|
|
auth_debug_add("Agent forwarding disabled.");
|
|
no_agent_forwarding_flag = 1;
|
|
opts += strlen(cp);
|
|
goto next_option;
|
|
}
|
|
cp = "no-X11-forwarding";
|
|
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
|
|
auth_debug_add("X11 forwarding disabled.");
|
|
no_x11_forwarding_flag = 1;
|
|
opts += strlen(cp);
|
|
goto next_option;
|
|
}
|
|
cp = "no-pty";
|
|
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
|
|
auth_debug_add("Pty allocation disabled.");
|
|
no_pty_flag = 1;
|
|
opts += strlen(cp);
|
|
goto next_option;
|
|
}
|
|
cp = "no-user-rc";
|
|
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
|
|
auth_debug_add("User rc file execution disabled.");
|
|
no_user_rc = 1;
|
|
opts += strlen(cp);
|
|
goto next_option;
|
|
}
|
|
cp = "command=\"";
|
|
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
|
|
opts += strlen(cp);
|
|
forced_command = xmalloc(strlen(opts) + 1);
|
|
i = 0;
|
|
while (*opts) {
|
|
if (*opts == '"')
|
|
break;
|
|
if (*opts == '\\' && opts[1] == '"') {
|
|
opts += 2;
|
|
forced_command[i++] = '"';
|
|
continue;
|
|
}
|
|
forced_command[i++] = *opts++;
|
|
}
|
|
if (!*opts) {
|
|
debug("%.100s, line %lu: missing end quote",
|
|
file, linenum);
|
|
auth_debug_add("%.100s, line %lu: missing end quote",
|
|
file, linenum);
|
|
xfree(forced_command);
|
|
forced_command = NULL;
|
|
goto bad_option;
|
|
}
|
|
forced_command[i] = '\0';
|
|
auth_debug_add("Forced command: %.900s", forced_command);
|
|
opts++;
|
|
goto next_option;
|
|
}
|
|
cp = "environment=\"";
|
|
if (options.permit_user_env &&
|
|
strncasecmp(opts, cp, strlen(cp)) == 0) {
|
|
char *s;
|
|
struct envstring *new_envstring;
|
|
|
|
opts += strlen(cp);
|
|
s = xmalloc(strlen(opts) + 1);
|
|
i = 0;
|
|
while (*opts) {
|
|
if (*opts == '"')
|
|
break;
|
|
if (*opts == '\\' && opts[1] == '"') {
|
|
opts += 2;
|
|
s[i++] = '"';
|
|
continue;
|
|
}
|
|
s[i++] = *opts++;
|
|
}
|
|
if (!*opts) {
|
|
debug("%.100s, line %lu: missing end quote",
|
|
file, linenum);
|
|
auth_debug_add("%.100s, line %lu: missing end quote",
|
|
file, linenum);
|
|
xfree(s);
|
|
goto bad_option;
|
|
}
|
|
s[i] = '\0';
|
|
auth_debug_add("Adding to environment: %.900s", s);
|
|
debug("Adding to environment: %.900s", s);
|
|
opts++;
|
|
new_envstring = xmalloc(sizeof(struct envstring));
|
|
new_envstring->s = s;
|
|
new_envstring->next = custom_environment;
|
|
custom_environment = new_envstring;
|
|
goto next_option;
|
|
}
|
|
cp = "from=\"";
|
|
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
|
|
const char *remote_ip = get_remote_ipaddr();
|
|
const char *remote_host = get_canonical_hostname(
|
|
options.use_dns);
|
|
char *patterns = xmalloc(strlen(opts) + 1);
|
|
|
|
opts += strlen(cp);
|
|
i = 0;
|
|
while (*opts) {
|
|
if (*opts == '"')
|
|
break;
|
|
if (*opts == '\\' && opts[1] == '"') {
|
|
opts += 2;
|
|
patterns[i++] = '"';
|
|
continue;
|
|
}
|
|
patterns[i++] = *opts++;
|
|
}
|
|
if (!*opts) {
|
|
debug("%.100s, line %lu: missing end quote",
|
|
file, linenum);
|
|
auth_debug_add("%.100s, line %lu: missing end quote",
|
|
file, linenum);
|
|
xfree(patterns);
|
|
goto bad_option;
|
|
}
|
|
patterns[i] = '\0';
|
|
opts++;
|
|
switch (match_host_and_ip(remote_host, remote_ip,
|
|
patterns)) {
|
|
case 1:
|
|
xfree(patterns);
|
|
/* Host name matches. */
|
|
goto next_option;
|
|
case -1:
|
|
debug("%.100s, line %lu: invalid criteria",
|
|
file, linenum);
|
|
auth_debug_add("%.100s, line %lu: "
|
|
"invalid criteria", file, linenum);
|
|
/* FALLTHROUGH */
|
|
case 0:
|
|
xfree(patterns);
|
|
logit("Authentication tried for %.100s with "
|
|
"correct key but not from a permitted "
|
|
"host (host=%.200s, ip=%.200s).",
|
|
pw->pw_name, remote_host, remote_ip);
|
|
auth_debug_add("Your host '%.200s' is not "
|
|
"permitted to use this key for login.",
|
|
remote_host);
|
|
break;
|
|
}
|
|
/* deny access */
|
|
return 0;
|
|
}
|
|
cp = "permitopen=\"";
|
|
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
|
|
char *host, *p;
|
|
u_short port;
|
|
char *patterns = xmalloc(strlen(opts) + 1);
|
|
|
|
opts += strlen(cp);
|
|
i = 0;
|
|
while (*opts) {
|
|
if (*opts == '"')
|
|
break;
|
|
if (*opts == '\\' && opts[1] == '"') {
|
|
opts += 2;
|
|
patterns[i++] = '"';
|
|
continue;
|
|
}
|
|
patterns[i++] = *opts++;
|
|
}
|
|
if (!*opts) {
|
|
debug("%.100s, line %lu: missing end quote",
|
|
file, linenum);
|
|
auth_debug_add("%.100s, line %lu: missing "
|
|
"end quote", file, linenum);
|
|
xfree(patterns);
|
|
goto bad_option;
|
|
}
|
|
patterns[i] = '\0';
|
|
opts++;
|
|
p = patterns;
|
|
host = hpdelim(&p);
|
|
if (host == NULL || strlen(host) >= NI_MAXHOST) {
|
|
debug("%.100s, line %lu: Bad permitopen "
|
|
"specification <%.100s>", file, linenum,
|
|
patterns);
|
|
auth_debug_add("%.100s, line %lu: "
|
|
"Bad permitopen specification", file,
|
|
linenum);
|
|
xfree(patterns);
|
|
goto bad_option;
|
|
}
|
|
host = cleanhostname(host);
|
|
if (p == NULL || (port = a2port(p)) == 0) {
|
|
debug("%.100s, line %lu: Bad permitopen port "
|
|
"<%.100s>", file, linenum, p ? p : "");
|
|
auth_debug_add("%.100s, line %lu: "
|
|
"Bad permitopen port", file, linenum);
|
|
xfree(patterns);
|
|
goto bad_option;
|
|
}
|
|
if (options.allow_tcp_forwarding)
|
|
channel_add_permitted_opens(host, port);
|
|
xfree(patterns);
|
|
goto next_option;
|
|
}
|
|
cp = "tunnel=\"";
|
|
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
|
|
char *tun = NULL;
|
|
opts += strlen(cp);
|
|
tun = xmalloc(strlen(opts) + 1);
|
|
i = 0;
|
|
while (*opts) {
|
|
if (*opts == '"')
|
|
break;
|
|
tun[i++] = *opts++;
|
|
}
|
|
if (!*opts) {
|
|
debug("%.100s, line %lu: missing end quote",
|
|
file, linenum);
|
|
auth_debug_add("%.100s, line %lu: missing end quote",
|
|
file, linenum);
|
|
xfree(tun);
|
|
forced_tun_device = -1;
|
|
goto bad_option;
|
|
}
|
|
tun[i] = '\0';
|
|
forced_tun_device = a2tun(tun, NULL);
|
|
xfree(tun);
|
|
if (forced_tun_device == SSH_TUNID_ERR) {
|
|
debug("%.100s, line %lu: invalid tun device",
|
|
file, linenum);
|
|
auth_debug_add("%.100s, line %lu: invalid tun device",
|
|
file, linenum);
|
|
forced_tun_device = -1;
|
|
goto bad_option;
|
|
}
|
|
auth_debug_add("Forced tun device: %d", forced_tun_device);
|
|
opts++;
|
|
goto next_option;
|
|
}
|
|
next_option:
|
|
/*
|
|
* Skip the comma, and move to the next option
|
|
* (or break out if there are no more).
|
|
*/
|
|
if (!*opts)
|
|
fatal("Bugs in auth-options.c option processing.");
|
|
if (*opts == ' ' || *opts == '\t')
|
|
break; /* End of options. */
|
|
if (*opts != ',')
|
|
goto bad_option;
|
|
opts++;
|
|
/* Process the next option. */
|
|
}
|
|
|
|
if (!use_privsep)
|
|
auth_debug_send();
|
|
|
|
/* grant access */
|
|
return 1;
|
|
|
|
bad_option:
|
|
logit("Bad options in %.100s file, line %lu: %.50s",
|
|
file, linenum, opts);
|
|
auth_debug_add("Bad options in %.100s file, line %lu: %.50s",
|
|
file, linenum, opts);
|
|
|
|
if (!use_privsep)
|
|
auth_debug_send();
|
|
|
|
/* deny access */
|
|
return 0;
|
|
}
|