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 /* import */ 31 extern ServerOptions options; 32 33 int 34 auth_rhosts_rsa_key_allowed(struct passwd *pw, char *cuser, char *chost, 35 Key *client_host_key) 36 { 37 HostStatus host_status; 38 39 /* Check if we would accept it using rhosts authentication. */ 40 if (!auth_rhosts(pw, cuser)) 41 return 0; 42 43 host_status = check_key_in_hostfiles(pw, client_host_key, 44 chost, _PATH_SSH_SYSTEM_HOSTFILE, 45 options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE); 46 47 return (host_status == HOST_OK); 48 } 49 50 /* 51 * Tries to authenticate the user using the .rhosts file and the host using 52 * its host key. Returns true if authentication succeeds. 53 */ 54 int 55 auth_rhosts_rsa(struct passwd *pw, char *cuser, Key *client_host_key) 56 { 57 char *chost; 58 59 debug("Trying rhosts with RSA host authentication for client user %.100s", 60 cuser); 61 62 if (pw == NULL || client_host_key == NULL || 63 client_host_key->rsa == NULL) 64 return 0; 65 66 chost = (char *)get_canonical_hostname(options.verify_reverse_mapping); 67 debug("Rhosts RSA authentication: canonical host %.900s", chost); 68 69 if (!auth_rhosts_rsa_key_allowed(pw, cuser, chost, client_host_key)) { 70 debug("Rhosts with RSA host authentication denied: unknown or invalid host key"); 71 packet_send_debug("Your host key cannot be verified: unknown or invalid host key."); 72 return 0; 73 } 74 /* A matching host key was found and is known. */ 75 76 /* Perform the challenge-response dialog with the client for the host key. */ 77 if (!auth_rsa_challenge_dialog(client_host_key)) { 78 log("Client on %.800s failed to respond correctly to host authentication.", 79 chost); 80 return 0; 81 } 82 /* 83 * We have authenticated the user using .rhosts or /etc/hosts.equiv, 84 * and the host using RSA. We accept the authentication. 85 */ 86 87 verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.", 88 pw->pw_name, cuser, chost); 89 packet_send_debug("Rhosts with RSA host authentication accepted."); 90 return 1; 91 } 92