113 lines
3.5 KiB
C
113 lines
3.5 KiB
C
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/*
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* Copyright (c) 2001 Markus Friedl. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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RCSID("$OpenBSD: auth2-chall.c,v 1.4 2001/03/28 22:43:31 markus Exp $");
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#include "ssh2.h"
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#include "auth.h"
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#include "packet.h"
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#include "xmalloc.h"
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#include "dispatch.h"
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#include "log.h"
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void send_userauth_into_request(Authctxt *authctxt, char *challenge, int echo);
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void input_userauth_info_response(int type, int plen, void *ctxt);
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/*
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* try challenge-reponse, return -1 (= postponed) if we have to
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* wait for the response.
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*/
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int
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auth2_challenge(Authctxt *authctxt, char *devs)
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{
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char *challenge;
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if (!authctxt->valid || authctxt->user == NULL)
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return 0;
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if ((challenge = get_challenge(authctxt, devs)) == NULL)
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return 0;
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send_userauth_into_request(authctxt, challenge, 0);
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dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE,
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&input_userauth_info_response);
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authctxt->postponed = 1;
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return 0;
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}
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void
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send_userauth_into_request(Authctxt *authctxt, char *challenge, int echo)
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{
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int nprompts = 1;
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packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
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/* name, instruction and language are unused */
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packet_put_cstring("");
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packet_put_cstring("");
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packet_put_cstring("");
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packet_put_int(nprompts);
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packet_put_cstring(challenge);
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packet_put_char(echo);
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packet_send();
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packet_write_wait();
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}
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void
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input_userauth_info_response(int type, int plen, void *ctxt)
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{
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Authctxt *authctxt = ctxt;
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int authenticated = 0;
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u_int nresp, rlen;
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char *response, *method = "challenge-reponse";
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if (authctxt == NULL)
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fatal("input_userauth_info_response: no authctxt");
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authctxt->postponed = 0; /* reset */
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nresp = packet_get_int();
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if (nresp == 1) {
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response = packet_get_string(&rlen);
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packet_done();
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if (strlen(response) == 0) {
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/*
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* if we received an empty response, resend challenge
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* with echo enabled
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*/
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char *challenge = get_challenge(authctxt, NULL);
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if (challenge != NULL) {
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send_userauth_into_request(authctxt,
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challenge, 1);
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authctxt->postponed = 1;
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}
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} else if (authctxt->valid) {
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authenticated = verify_response(authctxt, response);
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memset(response, 'r', rlen);
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}
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xfree(response);
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}
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/* unregister callback */
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if (!authctxt->postponed)
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dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, NULL);
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userauth_finish(authctxt, authenticated, method);
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}
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