104 lines
3.0 KiB
C
104 lines
3.0 KiB
C
/* $OpenBSD: auth-rh-rsa.c,v 1.43 2010/03/04 10:36:03 djm Exp $ */
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/*
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* Author: Tatu Ylonen <ylo@cs.hut.fi>
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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* All rights reserved
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* Rhosts or /etc/hosts.equiv authentication combined with RSA host
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* authentication.
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*
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* As far as I am concerned, the code I have written for this software
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* can be used freely for any purpose. Any derived versions of this
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* software must be clearly marked as such, and if the derived work is
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* incompatible with the protocol description in the RFC file, it must be
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* called by a name other than "ssh" or "Secure Shell".
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*/
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#include "includes.h"
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#include <sys/types.h>
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#include <pwd.h>
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#include <stdarg.h>
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#include "packet.h"
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#include "uidswap.h"
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#include "log.h"
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#include "buffer.h"
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#include "servconf.h"
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#include "key.h"
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#include "hostfile.h"
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#include "pathnames.h"
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#include "auth.h"
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#include "canohost.h"
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#ifdef GSSAPI
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#include "ssh-gss.h"
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#endif
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#include "monitor_wrap.h"
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/* import */
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extern ServerOptions options;
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int
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auth_rhosts_rsa_key_allowed(struct passwd *pw, char *cuser, char *chost,
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Key *client_host_key)
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{
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HostStatus host_status;
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if (auth_key_is_revoked(client_host_key))
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return 0;
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/* Check if we would accept it using rhosts authentication. */
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if (!auth_rhosts(pw, cuser))
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return 0;
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host_status = check_key_in_hostfiles(pw, client_host_key,
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chost, _PATH_SSH_SYSTEM_HOSTFILE,
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options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE);
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return (host_status == HOST_OK);
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}
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/*
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* Tries to authenticate the user using the .rhosts file and the host using
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* its host key. Returns true if authentication succeeds.
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*/
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int
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auth_rhosts_rsa(Authctxt *authctxt, char *cuser, Key *client_host_key)
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{
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char *chost;
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struct passwd *pw = authctxt->pw;
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debug("Trying rhosts with RSA host authentication for client user %.100s",
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cuser);
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if (!authctxt->valid || client_host_key == NULL ||
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client_host_key->rsa == NULL)
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return 0;
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chost = (char *)get_canonical_hostname(options.use_dns);
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debug("Rhosts RSA authentication: canonical host %.900s", chost);
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if (!PRIVSEP(auth_rhosts_rsa_key_allowed(pw, cuser, chost, client_host_key))) {
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debug("Rhosts with RSA host authentication denied: unknown or invalid host key");
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packet_send_debug("Your host key cannot be verified: unknown or invalid host key.");
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return 0;
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}
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/* A matching host key was found and is known. */
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/* Perform the challenge-response dialog with the client for the host key. */
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if (!auth_rsa_challenge_dialog(client_host_key)) {
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logit("Client on %.800s failed to respond correctly to host authentication.",
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chost);
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return 0;
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}
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/*
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* We have authenticated the user using .rhosts or /etc/hosts.equiv,
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* and the host using RSA. We accept the authentication.
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*/
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verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.",
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pw->pw_name, cuser, chost);
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packet_send_debug("Rhosts with RSA host authentication accepted.");
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return 1;
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}
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