/*
- *
- * auth-rsa.c
- *
* Author: Tatu Ylonen <ylo@cs.hut.fi>
- *
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
- *
- * Created: Mon Mar 27 01:46:52 1995 ylo
- *
* RSA-based authentication. This code determines whether to admit a login
* based on RSA authentication. This file also contains functions to check
* validity of the host key.
*
+ * 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"
-RCSID("$Id$");
+RCSID("$OpenBSD: auth-rsa.c,v 1.32 2000/10/14 12:19:45 markus Exp $");
#include "rsa.h"
#include "packet.h"
#include "uidswap.h"
#include "match.h"
#include "servconf.h"
+#include "auth-options.h"
#include <openssl/rsa.h>
#include <openssl/md5.h>
-/* Flags that may be set in authorized_keys options. */
-extern int no_port_forwarding_flag;
-extern int no_agent_forwarding_flag;
-extern int no_x11_forwarding_flag;
-extern int no_pty_flag;
-extern char *forced_command;
-extern struct envstring *custom_environment;
+
+/* import */
+extern ServerOptions options;
/*
* Session identifier that is used to bind key exchange and authentication
int
auth_rsa(struct passwd *pw, BIGNUM *client_n)
{
- extern ServerOptions options;
char line[8192], file[1024];
int authenticated;
unsigned int bits;
struct stat st;
RSA *pk;
+ /* no user given */
+ if (pw == NULL)
+ return 0;
+
/* Temporarily use the user's uid. */
temporarily_use_uid(pw->pw_uid);
}
if (fail) {
fclose(f);
- log(buf);
- packet_send_debug(buf);
+ log("%s",buf);
+ packet_send_debug("%s",buf);
restore_uid();
return 0;
}
}
} else
options = NULL;
+ /*
+ * If our options do not allow this key to be used,
+ * do not send challenge.
+ */
+ if (!auth_parse_options(pw, options, linenum))
+ continue;
/* Parse the key from the line. */
if (!auth_rsa_read_key(&cp, &bits, pk->e, pk->n)) {
/* We have found the desired key. */
-
/* Perform the challenge-response dialog for this key. */
if (!auth_rsa_challenge_dialog(pk)) {
/* Wrong response. */
* authenticated. Note that we have not yet processed the
* options; this will be reset if the options cause the
* authentication to be rejected.
- */
- authenticated = 1;
-
- /* RSA part of authentication was accepted. Now process the options. */
- if (options) {
- while (*options && *options != ' ' && *options != '\t') {
- cp = "no-port-forwarding";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- packet_send_debug("Port forwarding disabled.");
- no_port_forwarding_flag = 1;
- options += strlen(cp);
- goto next_option;
- }
- cp = "no-agent-forwarding";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- packet_send_debug("Agent forwarding disabled.");
- no_agent_forwarding_flag = 1;
- options += strlen(cp);
- goto next_option;
- }
- cp = "no-X11-forwarding";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- packet_send_debug("X11 forwarding disabled.");
- no_x11_forwarding_flag = 1;
- options += strlen(cp);
- goto next_option;
- }
- cp = "no-pty";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- packet_send_debug("Pty allocation disabled.");
- no_pty_flag = 1;
- options += strlen(cp);
- goto next_option;
- }
- cp = "command=\"";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- int i;
- options += strlen(cp);
- forced_command = xmalloc(strlen(options) + 1);
- i = 0;
- while (*options) {
- if (*options == '"')
- break;
- if (*options == '\\' && options[1] == '"') {
- options += 2;
- forced_command[i++] = '"';
- continue;
- }
- forced_command[i++] = *options++;
- }
- if (!*options) {
- debug("%.100s, line %lu: missing end quote",
- SSH_USER_PERMITTED_KEYS, linenum);
- packet_send_debug("%.100s, line %lu: missing end quote",
- SSH_USER_PERMITTED_KEYS, linenum);
- continue;
- }
- forced_command[i] = 0;
- packet_send_debug("Forced command: %.900s", forced_command);
- options++;
- goto next_option;
- }
- cp = "environment=\"";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- int i;
- char *s;
- struct envstring *new_envstring;
- options += strlen(cp);
- s = xmalloc(strlen(options) + 1);
- i = 0;
- while (*options) {
- if (*options == '"')
- break;
- if (*options == '\\' && options[1] == '"') {
- options += 2;
- s[i++] = '"';
- continue;
- }
- s[i++] = *options++;
- }
- if (!*options) {
- debug("%.100s, line %lu: missing end quote",
- SSH_USER_PERMITTED_KEYS, linenum);
- packet_send_debug("%.100s, line %lu: missing end quote",
- SSH_USER_PERMITTED_KEYS, linenum);
- continue;
- }
- s[i] = 0;
- packet_send_debug("Adding to environment: %.900s", s);
- debug("Adding to environment: %.900s", s);
- options++;
- 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 (strncmp(options, cp, strlen(cp)) == 0) {
- char *patterns = xmalloc(strlen(options) + 1);
- int i;
- options += strlen(cp);
- i = 0;
- while (*options) {
- if (*options == '"')
- break;
- if (*options == '\\' && options[1] == '"') {
- options += 2;
- patterns[i++] = '"';
- continue;
- }
- patterns[i++] = *options++;
- }
- if (!*options) {
- debug("%.100s, line %lu: missing end quote",
- SSH_USER_PERMITTED_KEYS, linenum);
- packet_send_debug("%.100s, line %lu: missing end quote",
- SSH_USER_PERMITTED_KEYS, linenum);
- continue;
- }
- patterns[i] = 0;
- options++;
- if (!match_hostname(get_canonical_hostname(), patterns,
- strlen(patterns)) &&
- !match_hostname(get_remote_ipaddr(), patterns,
- strlen(patterns))) {
- log("RSA authentication tried for %.100s with correct key but not from a permitted host (host=%.200s, ip=%.200s).",
- pw->pw_name, get_canonical_hostname(),
- get_remote_ipaddr());
- packet_send_debug("Your host '%.200s' is not permitted to use this key for login.",
- get_canonical_hostname());
- xfree(patterns);
- /* key invalid for this host, reset flags */
- authenticated = 0;
- no_agent_forwarding_flag = 0;
- no_port_forwarding_flag = 0;
- no_pty_flag = 0;
- no_x11_forwarding_flag = 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;
- }
- break;
- }
- xfree(patterns);
- /* Host name matches. */
- goto next_option;
- }
- bad_option:
- log("Bad options in %.100s file, line %lu: %.50s",
- SSH_USER_PERMITTED_KEYS, linenum, options);
- packet_send_debug("Bad options in %.100s file, line %lu: %.50s",
- SSH_USER_PERMITTED_KEYS, linenum, options);
- authenticated = 0;
- break;
-
- next_option:
- /*
- * Skip the comma, and move to the next option
- * (or break out if there are no more).
- */
- if (!*options)
- fatal("Bugs in auth-rsa.c option processing.");
- if (*options == ' ' || *options == '\t')
- break; /* End of options. */
- if (*options != ',')
- goto bad_option;
- options++;
- /* Process the next option. */
- continue;
- }
- }
- /*
* Break out of the loop if authentication was successful;
* otherwise continue searching.
*/
- if (authenticated)
- break;
+ authenticated = 1;
+ break;
}
/* Restore the privileged uid. */
if (authenticated)
packet_send_debug("RSA authentication accepted.");
+ else
+ auth_clear_options();
/* Return authentication result. */
return authenticated;