5 Author: Tatu Ylonen <ylo@cs.hut.fi>
7 Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
10 Created: Sun May 7 03:08:06 1995 ylo
12 Rhosts or /etc/hosts.equiv authentication combined with RSA host
26 /* Tries to authenticate the user using the .rhosts file and the host using
27 its host key. Returns true if authentication succeeds. */
29 int auth_rhosts_rsa(struct passwd *pw, const char *client_user,
30 BIGNUM *client_host_key_e, BIGNUM *client_host_key_n)
32 extern ServerOptions options;
33 const char *canonical_hostname;
34 HostStatus host_status;
37 debug("Trying rhosts with RSA host authentication for %.100s", client_user);
39 /* Check if we would accept it using rhosts authentication. */
40 if (!auth_rhosts(pw, client_user))
43 canonical_hostname = get_canonical_hostname();
45 debug("Rhosts RSA authentication: canonical host %.900s",
48 /* Check if we know the host and its host key. */
49 /* Check system-wide host file. */
52 host_status = check_host_in_hostfile(SSH_SYSTEM_HOSTFILE, canonical_hostname,
53 client_host_key_e, client_host_key_n, ke, kn);
55 /* Check user host file unless ignored. */
56 if (host_status != HOST_OK && !options.ignore_user_known_hosts) {
58 char *user_hostfile = tilde_expand_filename(SSH_USER_HOSTFILE, pw->pw_uid);
59 /* Check file permissions of SSH_USER_HOSTFILE,
60 auth_rsa() did already check pw->pw_dir, but there is a race XXX */
61 if (options.strict_modes &&
62 (stat(user_hostfile, &st) == 0) &&
63 ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
64 (st.st_mode & 022) != 0)) {
65 log("Rhosts RSA authentication refused for %.100s: bad owner or modes for %.200s",
66 pw->pw_name, user_hostfile);
68 /* XXX race between stat and the following open() */
69 temporarily_use_uid(pw->pw_uid);
70 host_status = check_host_in_hostfile(user_hostfile, canonical_hostname,
71 client_host_key_e, client_host_key_n, ke, kn);
79 if (host_status != HOST_OK) {
80 /* The host key was not found. */
81 debug("Rhosts with RSA host authentication denied: unknown or invalid host key");
82 packet_send_debug("Your host key cannot be verified: unknown or invalid host key.");
86 /* A matching host key was found and is known. */
88 /* Perform the challenge-response dialog with the client for the host key. */
89 if (!auth_rsa_challenge_dialog(client_host_key_e, client_host_key_n))
91 log("Client on %.800s failed to respond correctly to host authentication.",
96 /* We have authenticated the user using .rhosts or /etc/hosts.equiv, and
97 the host using RSA. We accept the authentication. */
99 log("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.",
100 pw->pw_name, client_user, canonical_hostname);
101 packet_send_debug("Rhosts with RSA host authentication accepted.");