1 /* 2 * Author: Tatu Ylonen <ylo@cs.hut.fi> 3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 4 * All rights reserved 5 * Rhosts or /etc/hosts.equiv authentication combined with RSA host 6 * authentication. 7 * 8 * As far as I am concerned, the code I have written for this software 9 * can be used freely for any purpose. Any derived versions of this 10 * software must be clearly marked as such, and if the derived work is 11 * incompatible with the protocol description in the RFC file, it must be 12 * called by a name other than "ssh" or "Secure Shell". 13 */ 14 15 #include "includes.h" 16 RCSID("$OpenBSD: auth-rh-rsa.c,v 1.34 2002/03/25 09:25:06 markus Exp $"); 17 18 #pragma ident "%Z%%M% %I% %E% SMI" 19 20 #include "packet.h" 21 #include "uidswap.h" 22 #include "log.h" 23 #include "servconf.h" 24 #include "key.h" 25 #include "hostfile.h" 26 #include "pathnames.h" 27 #include "auth.h" 28 #include "canohost.h" 29 30 #include "monitor_wrap.h" 31 32 /* import */ 33 extern ServerOptions options; 34 35 int 36 auth_rhosts_rsa_key_allowed(struct passwd *pw, char *cuser, char *chost, 37 Key *client_host_key) 38 { 39 HostStatus host_status; 40 41 /* Check if we would accept it using rhosts authentication. */ 42 if (!auth_rhosts(pw, cuser)) 43 return 0; 44 45 host_status = check_key_in_hostfiles(pw, client_host_key, 46 chost, _PATH_SSH_SYSTEM_HOSTFILE, 47 options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE); 48 49 return (host_status == HOST_OK); 50 } 51 52 /* 53 * Tries to authenticate the user using the .rhosts file and the host using 54 * its host key. Returns true if authentication succeeds. 55 */ 56 int 57 auth_rhosts_rsa(struct passwd *pw, char *cuser, Key *client_host_key) 58 { 59 char *chost; 60 61 debug("Trying rhosts with RSA host authentication for client user %.100s", 62 cuser); 63 64 if (pw == NULL || client_host_key == NULL || 65 client_host_key->rsa == NULL) 66 return 0; 67 68 chost = (char *)get_canonical_hostname(options.verify_reverse_mapping); 69 debug("Rhosts RSA authentication: canonical host %.900s", chost); 70 71 if (!PRIVSEP(auth_rhosts_rsa_key_allowed(pw, cuser, chost, client_host_key))) { 72 debug("Rhosts with RSA host authentication denied: unknown or invalid host key"); 73 packet_send_debug("Your host key cannot be verified: unknown or invalid host key."); 74 return 0; 75 } 76 /* A matching host key was found and is known. */ 77 78 /* Perform the challenge-response dialog with the client for the host key. */ 79 if (!auth_rsa_challenge_dialog(client_host_key)) { 80 log("Client on %.800s failed to respond correctly to host authentication.", 81 chost); 82 return 0; 83 } 84 /* 85 * We have authenticated the user using .rhosts or /etc/hosts.equiv, 86 * and the host using RSA. We accept the authentication. 87 */ 88 89 verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.", 90 pw->pw_name, cuser, chost); 91 packet_send_debug("Rhosts with RSA host authentication accepted."); 92 return 1; 93 } 94