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
25 /* Tries to authenticate the user using the .rhosts file and the host using
26 its host key. Returns true if authentication succeeds.
27 .rhosts and .shosts will be ignored if ignore_rhosts is non-zero. */
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,
32 int ignore_rhosts, int strict_modes)
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, ignore_rhosts, strict_modes))
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);
56 /* Check user host file. */
57 if (host_status != HOST_OK) {
59 char *user_hostfile = tilde_expand_filename(SSH_USER_HOSTFILE, pw->pw_uid);
60 /* Check file permissions of SSH_USER_HOSTFILE,
61 auth_rsa() did already check pw->pw_dir, but there is a race XXX */
63 (stat(user_hostfile, &st) == 0) &&
64 ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
65 (st.st_mode & 022) != 0)) {
66 log("Rhosts RSA authentication refused for %.100s: bad owner or modes for %.200s",
67 pw->pw_name, user_hostfile);
69 /* XXX race between stat and the following open() */
70 temporarily_use_uid(pw->pw_uid);
71 host_status = check_host_in_hostfile(user_hostfile, canonical_hostname,
72 client_host_key_bits, client_host_key_e,
73 client_host_key_n, ke, kn);
81 if (host_status != HOST_OK) {
82 /* The host key was not found. */
83 debug("Rhosts with RSA host authentication denied: unknown or invalid host key");
84 packet_send_debug("Your host key cannot be verified: unknown or invalid host key.");
88 /* A matching host key was found and is known. */
90 /* Perform the challenge-response dialog with the client for the host key. */
91 if (!auth_rsa_challenge_dialog(client_host_key_bits,
92 client_host_key_e, client_host_key_n))
94 log("Client on %.800s failed to respond correctly to host authentication.",
99 /* We have authenticated the user using .rhosts or /etc/hosts.equiv, and
100 the host using RSA. We accept the authentication. */
102 log("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.",
103 pw->pw_name, client_user, canonical_hostname);
104 packet_send_debug("Rhosts with RSA host authentication accepted.");