auth-rh-rsa.c revision 323124
1/* $OpenBSD: auth-rh-rsa.c,v 1.45 2016/03/07 19:02:43 djm Exp $ */ 2/* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * Rhosts or /etc/hosts.equiv authentication combined with RSA host 7 * authentication. 8 * 9 * As far as I am concerned, the code I have written for this software 10 * can be used freely for any purpose. Any derived versions of this 11 * software must be clearly marked as such, and if the derived work is 12 * incompatible with the protocol description in the RFC file, it must be 13 * called by a name other than "ssh" or "Secure Shell". 14 */ 15 16#include "includes.h" 17 18#ifdef WITH_SSH1 19 20#include <sys/types.h> 21 22#include <pwd.h> 23#include <stdarg.h> 24 25#include "packet.h" 26#include "uidswap.h" 27#include "log.h" 28#include "buffer.h" 29#include "misc.h" 30#include "servconf.h" 31#include "key.h" 32#include "hostfile.h" 33#include "pathnames.h" 34#include "auth.h" 35#include "canohost.h" 36#ifdef GSSAPI 37#include "ssh-gss.h" 38#endif 39#include "monitor_wrap.h" 40 41/* import */ 42extern ServerOptions options; 43 44int 45auth_rhosts_rsa_key_allowed(struct passwd *pw, const char *cuser, 46 const char *chost, Key *client_host_key) 47{ 48 HostStatus host_status; 49 50 if (auth_key_is_revoked(client_host_key)) 51 return 0; 52 53 /* Check if we would accept it using rhosts authentication. */ 54 if (!auth_rhosts(pw, cuser)) 55 return 0; 56 57 host_status = check_key_in_hostfiles(pw, client_host_key, 58 chost, _PATH_SSH_SYSTEM_HOSTFILE, 59 options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE); 60 61 return (host_status == HOST_OK); 62} 63 64/* 65 * Tries to authenticate the user using the .rhosts file and the host using 66 * its host key. Returns true if authentication succeeds. 67 */ 68int 69auth_rhosts_rsa(Authctxt *authctxt, char *cuser, Key *client_host_key) 70{ 71 struct ssh *ssh = active_state; /* XXX */ 72 const char *chost; 73 struct passwd *pw = authctxt->pw; 74 75 debug("Trying rhosts with RSA host authentication for client user %.100s", 76 cuser); 77 78 if (!authctxt->valid || client_host_key == NULL || 79 client_host_key->rsa == NULL) 80 return 0; 81 82 chost = auth_get_canonical_hostname(ssh, options.use_dns); 83 debug("Rhosts RSA authentication: canonical host %.900s", chost); 84 85 if (!PRIVSEP(auth_rhosts_rsa_key_allowed(pw, cuser, chost, client_host_key))) { 86 debug("Rhosts with RSA host authentication denied: unknown or invalid host key"); 87 packet_send_debug("Your host key cannot be verified: unknown or invalid host key."); 88 return 0; 89 } 90 /* A matching host key was found and is known. */ 91 92 /* Perform the challenge-response dialog with the client for the host key. */ 93 if (!auth_rsa_challenge_dialog(client_host_key)) { 94 logit("Client on %.800s failed to respond correctly to host authentication.", 95 chost); 96 return 0; 97 } 98 /* 99 * We have authenticated the user using .rhosts or /etc/hosts.equiv, 100 * and the host using RSA. We accept the authentication. 101 */ 102 103 verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.", 104 pw->pw_name, cuser, chost); 105 packet_send_debug("Rhosts with RSA host authentication accepted."); 106 return 1; 107} 108 109#endif /* WITH_SSH1 */ 110