1 /* $OpenBSD: auth-rh-rsa.c,v 1.44 2014/07/15 15:54:14 millert Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo (at) cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo (at) 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 */ 42 extern ServerOptions options; 43 44 int 45 auth_rhosts_rsa_key_allowed(struct passwd *pw, char *cuser, char *chost, 46 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 */ 68 int 69 auth_rhosts_rsa(Authctxt *authctxt, char *cuser, Key *client_host_key) 70 { 71 char *chost; 72 struct passwd *pw = authctxt->pw; 73 74 debug("Trying rhosts with RSA host authentication for client user %.100s", 75 cuser); 76 77 if (!authctxt->valid || client_host_key == NULL || 78 client_host_key->rsa == NULL) 79 return 0; 80 81 chost = (char *)get_canonical_hostname(options.use_dns); 82 debug("Rhosts RSA authentication: canonical host %.900s", chost); 83 84 if (!PRIVSEP(auth_rhosts_rsa_key_allowed(pw, cuser, chost, client_host_key))) { 85 debug("Rhosts with RSA host authentication denied: unknown or invalid host key"); 86 packet_send_debug("Your host key cannot be verified: unknown or invalid host key."); 87 return 0; 88 } 89 /* A matching host key was found and is known. */ 90 91 /* Perform the challenge-response dialog with the client for the host key. */ 92 if (!auth_rsa_challenge_dialog(client_host_key)) { 93 logit("Client on %.800s failed to respond correctly to host authentication.", 94 chost); 95 return 0; 96 } 97 /* 98 * We have authenticated the user using .rhosts or /etc/hosts.equiv, 99 * and the host using RSA. We accept the authentication. 100 */ 101 102 verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.", 103 pw->pw_name, cuser, chost); 104 packet_send_debug("Rhosts with RSA host authentication accepted."); 105 return 1; 106 } 107 108 #endif /* WITH_SSH1 */ 109
