Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame^] | 1 | /* $OpenBSD: auth-rh-rsa.c,v 1.41 2006/07/06 16:03:53 stevesk Exp $ */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 5 | * All rights reserved |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 6 | * Rhosts or /etc/hosts.equiv authentication combined with RSA host |
| 7 | * authentication. |
| 8 | * |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 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". |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 14 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 15 | |
| 16 | #include "includes.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 17 | |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame^] | 18 | #include <sys/types.h> |
| 19 | |
| 20 | #include <pwd.h> |
| 21 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 22 | #include "packet.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 23 | #include "uidswap.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 24 | #include "log.h" |
Damien Miller | 3226509 | 1999-11-12 11:33:04 +1100 | [diff] [blame] | 25 | #include "servconf.h" |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 26 | #include "key.h" |
| 27 | #include "hostfile.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 28 | #include "pathnames.h" |
| 29 | #include "auth.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 30 | #include "canohost.h" |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 31 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 32 | #include "monitor_wrap.h" |
| 33 | |
Ben Lindstrom | 186b7da | 2002-03-22 01:20:32 +0000 | [diff] [blame] | 34 | /* import */ |
| 35 | extern ServerOptions options; |
| 36 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 37 | int |
Ben Lindstrom | 186b7da | 2002-03-22 01:20:32 +0000 | [diff] [blame] | 38 | auth_rhosts_rsa_key_allowed(struct passwd *pw, char *cuser, char *chost, |
| 39 | Key *client_host_key) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 40 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 41 | HostStatus host_status; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 42 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 43 | /* Check if we would accept it using rhosts authentication. */ |
Ben Lindstrom | 186b7da | 2002-03-22 01:20:32 +0000 | [diff] [blame] | 44 | if (!auth_rhosts(pw, cuser)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 45 | return 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 46 | |
Damien Miller | d221ca6 | 2002-01-22 23:11:00 +1100 | [diff] [blame] | 47 | host_status = check_key_in_hostfiles(pw, client_host_key, |
Ben Lindstrom | 186b7da | 2002-03-22 01:20:32 +0000 | [diff] [blame] | 48 | chost, _PATH_SSH_SYSTEM_HOSTFILE, |
Ben Lindstrom | a4789ef | 2001-06-25 04:40:49 +0000 | [diff] [blame] | 49 | options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE); |
Damien Miller | 33e511e | 1999-11-11 11:43:13 +1100 | [diff] [blame] | 50 | |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 51 | return (host_status == HOST_OK); |
Ben Lindstrom | 186b7da | 2002-03-22 01:20:32 +0000 | [diff] [blame] | 52 | } |
| 53 | |
| 54 | /* |
| 55 | * Tries to authenticate the user using the .rhosts file and the host using |
| 56 | * its host key. Returns true if authentication succeeds. |
| 57 | */ |
| 58 | int |
Damien Miller | 3e3b514 | 2003-11-17 21:13:40 +1100 | [diff] [blame] | 59 | auth_rhosts_rsa(Authctxt *authctxt, char *cuser, Key *client_host_key) |
Ben Lindstrom | 186b7da | 2002-03-22 01:20:32 +0000 | [diff] [blame] | 60 | { |
| 61 | char *chost; |
Damien Miller | 3e3b514 | 2003-11-17 21:13:40 +1100 | [diff] [blame] | 62 | struct passwd *pw = authctxt->pw; |
Ben Lindstrom | 186b7da | 2002-03-22 01:20:32 +0000 | [diff] [blame] | 63 | |
| 64 | debug("Trying rhosts with RSA host authentication for client user %.100s", |
| 65 | cuser); |
| 66 | |
Damien Miller | 3e3b514 | 2003-11-17 21:13:40 +1100 | [diff] [blame] | 67 | if (!authctxt->valid || client_host_key == NULL || |
Ben Lindstrom | 186b7da | 2002-03-22 01:20:32 +0000 | [diff] [blame] | 68 | client_host_key->rsa == NULL) |
| 69 | return 0; |
| 70 | |
Damien Miller | 3a961dc | 2003-06-03 10:25:48 +1000 | [diff] [blame] | 71 | chost = (char *)get_canonical_hostname(options.use_dns); |
Ben Lindstrom | 186b7da | 2002-03-22 01:20:32 +0000 | [diff] [blame] | 72 | debug("Rhosts RSA authentication: canonical host %.900s", chost); |
| 73 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 74 | if (!PRIVSEP(auth_rhosts_rsa_key_allowed(pw, cuser, chost, client_host_key))) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 75 | debug("Rhosts with RSA host authentication denied: unknown or invalid host key"); |
| 76 | packet_send_debug("Your host key cannot be verified: unknown or invalid host key."); |
| 77 | return 0; |
| 78 | } |
| 79 | /* A matching host key was found and is known. */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 80 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 81 | /* Perform the challenge-response dialog with the client for the host key. */ |
Ben Lindstrom | 9c8aefe | 2002-03-22 01:12:58 +0000 | [diff] [blame] | 82 | if (!auth_rsa_challenge_dialog(client_host_key)) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 83 | logit("Client on %.800s failed to respond correctly to host authentication.", |
Ben Lindstrom | 186b7da | 2002-03-22 01:20:32 +0000 | [diff] [blame] | 84 | chost); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 85 | return 0; |
| 86 | } |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 87 | /* |
| 88 | * We have authenticated the user using .rhosts or /etc/hosts.equiv, |
| 89 | * and the host using RSA. We accept the authentication. |
| 90 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 91 | |
| 92 | verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.", |
Damien Miller | 0dc1bef | 2005-07-17 17:22:45 +1000 | [diff] [blame] | 93 | pw->pw_name, cuser, chost); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 94 | packet_send_debug("Rhosts with RSA host authentication accepted."); |
| 95 | return 1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 96 | } |