auth-rh-rsa.c revision 149753
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" 16RCSID("$OpenBSD: auth-rh-rsa.c,v 1.38 2005/07/17 07:17:54 djm Exp $"); 17 18#include "packet.h" 19#include "uidswap.h" 20#include "log.h" 21#include "servconf.h" 22#include "key.h" 23#include "hostfile.h" 24#include "pathnames.h" 25#include "auth.h" 26#include "canohost.h" 27 28#include "monitor_wrap.h" 29 30/* import */ 31extern ServerOptions options; 32 33int 34auth_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 */ 54int 55auth_rhosts_rsa(Authctxt *authctxt, char *cuser, Key *client_host_key) 56{ 57 char *chost; 58 struct passwd *pw = authctxt->pw; 59 60 debug("Trying rhosts with RSA host authentication for client user %.100s", 61 cuser); 62 63 if (!authctxt->valid || client_host_key == NULL || 64 client_host_key->rsa == NULL) 65 return 0; 66 67 chost = (char *)get_canonical_hostname(options.use_dns); 68 debug("Rhosts RSA authentication: canonical host %.900s", chost); 69 70 if (!PRIVSEP(auth_rhosts_rsa_key_allowed(pw, cuser, chost, client_host_key))) { 71 debug("Rhosts with RSA host authentication denied: unknown or invalid host key"); 72 packet_send_debug("Your host key cannot be verified: unknown or invalid host key."); 73 return 0; 74 } 75 /* A matching host key was found and is known. */ 76 77 /* Perform the challenge-response dialog with the client for the host key. */ 78 if (!auth_rsa_challenge_dialog(client_host_key)) { 79 logit("Client on %.800s failed to respond correctly to host authentication.", 80 chost); 81 return 0; 82 } 83 /* 84 * We have authenticated the user using .rhosts or /etc/hosts.equiv, 85 * and the host using RSA. We accept the authentication. 86 */ 87 88 verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.", 89 pw->pw_name, cuser, chost); 90 packet_send_debug("Rhosts with RSA host authentication accepted."); 91 return 1; 92} 93