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 unsigned int client_host_key_bits,
31 BIGNUM *client_host_key_e, BIGNUM *client_host_key_n)
33 extern ServerOptions options;
34 const char *canonical_hostname;
35 HostStatus host_status;
38 debug("Trying rhosts with RSA host authentication for %.100s", client_user);
40 /* Check if we would accept it using rhosts authentication. */
41 if (!auth_rhosts(pw, client_user))
44 canonical_hostname = get_canonical_hostname();
46 debug("Rhosts RSA authentication: canonical host %.900s",
49 /* Check if we know the host and its host key. */
50 /* Check system-wide host file. */
53 host_status = check_host_in_hostfile(SSH_SYSTEM_HOSTFILE, canonical_hostname,
54 client_host_key_bits, client_host_key_e,
55 client_host_key_n, ke, kn);
57 /* Check user host file unless ignored. */
58 if (host_status != HOST_OK && !options.ignore_user_known_hosts) {
60 char *user_hostfile = tilde_expand_filename(SSH_USER_HOSTFILE, pw->pw_uid);
61 /* Check file permissions of SSH_USER_HOSTFILE,
62 auth_rsa() did already check pw->pw_dir, but there is a race XXX */
63 if (options.strict_modes &&
64 (stat(user_hostfile, &st) == 0) &&
65 ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
66 (st.st_mode & 022) != 0)) {
67 log("Rhosts RSA authentication refused for %.100s: bad owner or modes for %.200s",
68 pw->pw_name, user_hostfile);
70 /* XXX race between stat and the following open() */
71 temporarily_use_uid(pw->pw_uid);
72 host_status = check_host_in_hostfile(user_hostfile, canonical_hostname,
73 client_host_key_bits, client_host_key_e,
74 client_host_key_n, ke, kn);
82 if (host_status != HOST_OK) {
83 /* The host key was not found. */
84 debug("Rhosts with RSA host authentication denied: unknown or invalid host key");
85 packet_send_debug("Your host key cannot be verified: unknown or invalid host key.");
89 /* A matching host key was found and is known. */
91 /* Perform the challenge-response dialog with the client for the host key. */
92 if (!auth_rsa_challenge_dialog(client_host_key_bits,
93 client_host_key_e, client_host_key_n))
95 log("Client on %.800s failed to respond correctly to host authentication.",
100 /* We have authenticated the user using .rhosts or /etc/hosts.equiv, and
101 the host using RSA. We accept the authentication. */
103 log("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.",
104 pw->pw_name, client_user, canonical_hostname);
105 packet_send_debug("Rhosts with RSA host authentication accepted.");