Annotation of src/usr.bin/ssh/auth-rh-rsa.c, Revision 1.11
1.1 provos 1: /*
1.9 deraadt 2: *
3: * auth-rh-rsa.c
4: *
5: * Author: Tatu Ylonen <ylo@cs.hut.fi>
6: *
7: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
8: * All rights reserved
9: *
10: * Created: Sun May 7 03:08:06 1995 ylo
11: *
12: * Rhosts or /etc/hosts.equiv authentication combined with RSA host
13: * authentication.
14: *
15: */
1.1 provos 16:
17: #include "includes.h"
1.11 ! markus 18: RCSID("$Id: auth-rh-rsa.c,v 1.5 2000/02/17 17:24:08 markus Exp $");
1.1 provos 19:
20: #include "packet.h"
21: #include "ssh.h"
22: #include "xmalloc.h"
23: #include "uidswap.h"
1.4 markus 24: #include "servconf.h"
1.1 provos 25:
1.11 ! markus 26: #include <ssl/rsa.h>
! 27: #include <ssl/dsa.h>
! 28: #include "key.h"
! 29: #include "hostfile.h"
! 30:
1.10 markus 31: /*
32: * Tries to authenticate the user using the .rhosts file and the host using
33: * its host key. Returns true if authentication succeeds.
34: */
1.1 provos 35:
1.8 markus 36: int
1.11 ! markus 37: auth_rhosts_rsa(struct passwd *pw, const char *client_user, RSA *client_host_key)
1.1 provos 38: {
1.8 markus 39: extern ServerOptions options;
40: const char *canonical_hostname;
41: HostStatus host_status;
1.11 ! markus 42: Key *client_key, *found;
1.8 markus 43:
44: debug("Trying rhosts with RSA host authentication for %.100s", client_user);
45:
1.11 ! markus 46: if (client_host_key == NULL)
! 47: return 0;
! 48:
1.8 markus 49: /* Check if we would accept it using rhosts authentication. */
50: if (!auth_rhosts(pw, client_user))
51: return 0;
52:
53: canonical_hostname = get_canonical_hostname();
54:
1.11 ! markus 55: debug("Rhosts RSA authentication: canonical host %.900s", canonical_hostname);
! 56:
! 57: /* wrap the RSA key into a 'generic' key */
! 58: client_key = key_new(KEY_RSA);
! 59: BN_copy(client_key->rsa->e, client_host_key->e);
! 60: BN_copy(client_key->rsa->n, client_host_key->n);
! 61: found = key_new(KEY_RSA);
1.8 markus 62:
63: /* Check if we know the host and its host key. */
64: host_status = check_host_in_hostfile(SSH_SYSTEM_HOSTFILE, canonical_hostname,
1.11 ! markus 65: client_key, found);
1.8 markus 66:
67: /* Check user host file unless ignored. */
68: if (host_status != HOST_OK && !options.ignore_user_known_hosts) {
69: struct stat st;
70: char *user_hostfile = tilde_expand_filename(SSH_USER_HOSTFILE, pw->pw_uid);
1.10 markus 71: /*
72: * Check file permissions of SSH_USER_HOSTFILE, auth_rsa()
73: * did already check pw->pw_dir, but there is a race XXX
74: */
1.8 markus 75: if (options.strict_modes &&
76: (stat(user_hostfile, &st) == 0) &&
77: ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
78: (st.st_mode & 022) != 0)) {
79: log("Rhosts RSA authentication refused for %.100s: bad owner or modes for %.200s",
80: pw->pw_name, user_hostfile);
81: } else {
82: /* XXX race between stat and the following open() */
83: temporarily_use_uid(pw->pw_uid);
84: host_status = check_host_in_hostfile(user_hostfile, canonical_hostname,
1.11 ! markus 85: client_key, found);
1.8 markus 86: restore_uid();
87: }
88: xfree(user_hostfile);
89: }
1.11 ! markus 90: key_free(client_key);
! 91: key_free(found);
1.8 markus 92:
93: if (host_status != HOST_OK) {
94: debug("Rhosts with RSA host authentication denied: unknown or invalid host key");
95: packet_send_debug("Your host key cannot be verified: unknown or invalid host key.");
96: return 0;
97: }
98: /* A matching host key was found and is known. */
99:
100: /* Perform the challenge-response dialog with the client for the host key. */
1.11 ! markus 101: if (!auth_rsa_challenge_dialog(client_host_key)) {
1.8 markus 102: log("Client on %.800s failed to respond correctly to host authentication.",
103: canonical_hostname);
104: return 0;
105: }
1.10 markus 106: /*
107: * We have authenticated the user using .rhosts or /etc/hosts.equiv,
108: * and the host using RSA. We accept the authentication.
109: */
1.8 markus 110:
111: verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.",
1.11 ! markus 112: pw->pw_name, client_user, canonical_hostname);
1.8 markus 113: packet_send_debug("Rhosts with RSA host authentication accepted.");
114: return 1;
1.1 provos 115: }