/*
-
-auth-rh-rsa.c
-
-Author: Tatu Ylonen <ylo@cs.hut.fi>
-
-Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
- All rights reserved
-
-Created: Sun May 7 03:08:06 1995 ylo
-
-Rhosts or /etc/hosts.equiv authentication combined with RSA host
-authentication.
-
-*/
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ * All rights reserved
+ * Rhosts or /etc/hosts.equiv authentication combined with RSA host
+ * authentication.
+ *
+ * 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-rh-rsa.c,v 1.17 2000/10/03 18:03:03 markus Exp $");
#include "packet.h"
#include "ssh.h"
#include "xmalloc.h"
#include "uidswap.h"
+#include "servconf.h"
-/* Tries to authenticate the user using the .rhosts file and the host using
- its host key. Returns true if authentication succeeds.
- .rhosts and .shosts will be ignored if ignore_rhosts is non-zero. */
+#include <openssl/rsa.h>
+#include <openssl/dsa.h>
+#include "key.h"
+#include "hostfile.h"
+
+/*
+ * Tries to authenticate the user using the .rhosts file and the host using
+ * its host key. Returns true if authentication succeeds.
+ */
-int auth_rhosts_rsa(struct passwd *pw, const char *client_user,
- unsigned int client_host_key_bits,
- BIGNUM *client_host_key_e, BIGNUM *client_host_key_n,
- int ignore_rhosts, int strict_modes)
+int
+auth_rhosts_rsa(struct passwd *pw, const char *client_user, RSA *client_host_key)
{
- const char *canonical_hostname;
- HostStatus host_status;
- BIGNUM *ke, *kn;
-
- debug("Trying rhosts with RSA host authentication for %.100s", client_user);
-
- /* Check if we would accept it using rhosts authentication. */
- if (!auth_rhosts(pw, client_user, ignore_rhosts, strict_modes))
- return 0;
-
- canonical_hostname = get_canonical_hostname();
-
- debug("Rhosts RSA authentication: canonical host %.900s",
- canonical_hostname);
-
- /* Check if we know the host and its host key. */
- /* Check system-wide host file. */
- ke = BN_new();
- kn = BN_new();
- host_status = check_host_in_hostfile(SSH_SYSTEM_HOSTFILE, canonical_hostname,
- client_host_key_bits, client_host_key_e,
- client_host_key_n, ke, kn);
- BN_free(ke);
- BN_free(kn);
- if (host_status != HOST_OK) {
- /* The host key was not found. */
- debug("Rhosts with RSA host authentication denied: unknown or invalid host key");
- packet_send_debug("Your host key cannot be verified: unknown or invalid host key.");
- return 0;
- }
-
- /* A matching host key was found and is known. */
-
- /* Perform the challenge-response dialog with the client for the host key. */
- if (!auth_rsa_challenge_dialog(client_host_key_bits,
- client_host_key_e, client_host_key_n))
- {
- log("Client on %.800s failed to respond correctly to host authentication.",
- canonical_hostname);
- return 0;
- }
-
- /* We have authenticated the user using .rhosts or /etc/hosts.equiv, and
- the host using RSA. We accept the authentication. */
-
- log("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.",
- pw->pw_name, client_user, canonical_hostname);
- packet_send_debug("Rhosts with RSA host authentication accepted.");
- return 1;
+ extern ServerOptions options;
+ const char *canonical_hostname;
+ HostStatus host_status;
+ Key *client_key, *found;
+
+ debug("Trying rhosts with RSA host authentication for client user %.100s", client_user);
+
+ if (pw == NULL || client_host_key == NULL)
+ return 0;
+
+ /* Check if we would accept it using rhosts authentication. */
+ if (!auth_rhosts(pw, client_user))
+ return 0;
+
+ canonical_hostname = get_canonical_hostname();
+
+ debug("Rhosts RSA authentication: canonical host %.900s", canonical_hostname);
+
+ /* wrap the RSA key into a 'generic' key */
+ client_key = key_new(KEY_RSA);
+ BN_copy(client_key->rsa->e, client_host_key->e);
+ BN_copy(client_key->rsa->n, client_host_key->n);
+ found = key_new(KEY_RSA);
+
+ /* Check if we know the host and its host key. */
+ host_status = check_host_in_hostfile(SSH_SYSTEM_HOSTFILE, canonical_hostname,
+ client_key, found);
+
+ /* Check user host file unless ignored. */
+ if (host_status != HOST_OK && !options.ignore_user_known_hosts) {
+ struct stat st;
+ char *user_hostfile = tilde_expand_filename(SSH_USER_HOSTFILE, pw->pw_uid);
+ /*
+ * Check file permissions of SSH_USER_HOSTFILE, auth_rsa()
+ * did already check pw->pw_dir, but there is a race XXX
+ */
+ if (options.strict_modes &&
+ (stat(user_hostfile, &st) == 0) &&
+ ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
+ (st.st_mode & 022) != 0)) {
+ log("Rhosts RSA authentication refused for %.100s: bad owner or modes for %.200s",
+ pw->pw_name, user_hostfile);
+ } else {
+ /* XXX race between stat and the following open() */
+ temporarily_use_uid(pw->pw_uid);
+ host_status = check_host_in_hostfile(user_hostfile, canonical_hostname,
+ client_key, found);
+ restore_uid();
+ }
+ xfree(user_hostfile);
+ }
+ key_free(client_key);
+ key_free(found);
+
+ if (host_status != HOST_OK) {
+ debug("Rhosts with RSA host authentication denied: unknown or invalid host key");
+ packet_send_debug("Your host key cannot be verified: unknown or invalid host key.");
+ return 0;
+ }
+ /* A matching host key was found and is known. */
+
+ /* Perform the challenge-response dialog with the client for the host key. */
+ if (!auth_rsa_challenge_dialog(client_host_key)) {
+ log("Client on %.800s failed to respond correctly to host authentication.",
+ canonical_hostname);
+ return 0;
+ }
+ /*
+ * We have authenticated the user using .rhosts or /etc/hosts.equiv,
+ * and the host using RSA. We accept the authentication.
+ */
+
+ verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.",
+ pw->pw_name, client_user, canonical_hostname);
+ packet_send_debug("Rhosts with RSA host authentication accepted.");
+ return 1;
}
andersk / openssh.git / blobdiff