Mike Lockwood | 1305e95 | 2011-12-07 08:17:59 -0800 | [diff] [blame] | 1 | /* $OpenBSD: auth-rh-rsa.c,v 1.43 2010/03/04 10:36:03 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 | #include <sys/types.h> |
| 19 | |
| 20 | #include <pwd.h> |
| 21 | #include <stdarg.h> |
| 22 | |
| 23 | #include "packet.h" |
| 24 | #include "uidswap.h" |
| 25 | #include "log.h" |
| 26 | #include "buffer.h" |
| 27 | #include "servconf.h" |
| 28 | #include "key.h" |
| 29 | #include "hostfile.h" |
| 30 | #include "pathnames.h" |
| 31 | #include "auth.h" |
| 32 | #include "canohost.h" |
| 33 | #ifdef GSSAPI |
| 34 | #include "ssh-gss.h" |
| 35 | #endif |
| 36 | #include "monitor_wrap.h" |
| 37 | |
| 38 | /* import */ |
| 39 | extern ServerOptions options; |
| 40 | |
| 41 | int |
| 42 | auth_rhosts_rsa_key_allowed(struct passwd *pw, char *cuser, char *chost, |
| 43 | Key *client_host_key) |
| 44 | { |
| 45 | HostStatus host_status; |
| 46 | |
| 47 | if (auth_key_is_revoked(client_host_key)) |
| 48 | return 0; |
| 49 | |
| 50 | /* Check if we would accept it using rhosts authentication. */ |
| 51 | if (!auth_rhosts(pw, cuser)) |
| 52 | return 0; |
| 53 | |
| 54 | host_status = check_key_in_hostfiles(pw, client_host_key, |
| 55 | chost, _PATH_SSH_SYSTEM_HOSTFILE, |
| 56 | options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE); |
| 57 | |
| 58 | return (host_status == HOST_OK); |
| 59 | } |
| 60 | |
| 61 | /* |
| 62 | * Tries to authenticate the user using the .rhosts file and the host using |
| 63 | * its host key. Returns true if authentication succeeds. |
| 64 | */ |
| 65 | int |
| 66 | auth_rhosts_rsa(Authctxt *authctxt, char *cuser, Key *client_host_key) |
| 67 | { |
| 68 | char *chost; |
| 69 | struct passwd *pw = authctxt->pw; |
| 70 | |
| 71 | debug("Trying rhosts with RSA host authentication for client user %.100s", |
| 72 | cuser); |
| 73 | |
| 74 | if (!authctxt->valid || client_host_key == NULL || |
| 75 | client_host_key->rsa == NULL) |
| 76 | return 0; |
| 77 | |
| 78 | chost = (char *)get_canonical_hostname(options.use_dns); |
| 79 | debug("Rhosts RSA authentication: canonical host %.900s", chost); |
| 80 | |
| 81 | if (!PRIVSEP(auth_rhosts_rsa_key_allowed(pw, cuser, chost, client_host_key))) { |
| 82 | debug("Rhosts with RSA host authentication denied: unknown or invalid host key"); |
| 83 | packet_send_debug("Your host key cannot be verified: unknown or invalid host key."); |
| 84 | return 0; |
| 85 | } |
| 86 | /* A matching host key was found and is known. */ |
| 87 | |
| 88 | /* Perform the challenge-response dialog with the client for the host key. */ |
| 89 | if (!auth_rsa_challenge_dialog(client_host_key)) { |
| 90 | logit("Client on %.800s failed to respond correctly to host authentication.", |
| 91 | chost); |
| 92 | return 0; |
| 93 | } |
| 94 | /* |
| 95 | * We have authenticated the user using .rhosts or /etc/hosts.equiv, |
| 96 | * and the host using RSA. We accept the authentication. |
| 97 | */ |
| 98 | |
| 99 | verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.", |
| 100 | pw->pw_name, cuser, chost); |
| 101 | packet_send_debug("Rhosts with RSA host authentication accepted."); |
| 102 | return 1; |
| 103 | } |