Return to auth2-chall.c CVS log

Up to [local] / src / usr.bin / ssh

Annotation of src/usr.bin/ssh/auth2-chall.c, Revision 1.3

1.1       markus      1: /*
1.3     ! deraadt     2:  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
1.1       markus      3:  *
                      4:  * Redistribution and use in source and binary forms, with or without
                      5:  * modification, are permitted provided that the following conditions
                      6:  * are met:
                      7:  * 1. Redistributions of source code must retain the above copyright
                      8:  *    notice, this list of conditions and the following disclaimer.
                      9:  * 2. Redistributions in binary form must reproduce the above copyright
                     10:  *    notice, this list of conditions and the following disclaimer in the
                     11:  *    documentation and/or other materials provided with the distribution.
                     12:  *
                     13:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
                     14:  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
                     15:  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
                     16:  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
                     17:  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
                     18:  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
                     19:  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
                     20:  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
                     21:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
                     22:  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
                     23:  */
                     24: #include "includes.h"
1.3     ! deraadt    25: RCSID("$OpenBSD: auth2-chall.c,v 1.2 2001/01/21 19:05:43 markus Exp $");
1.1       markus     26:
                     27: #include "ssh2.h"
                     28: #include "auth.h"
                     29: #include "packet.h"
                     30: #include "xmalloc.h"
                     31: #include "dispatch.h"
1.2       markus     32: #include "log.h"
1.1       markus     33:
                     34: void send_userauth_into_request(Authctxt *authctxt, char *challenge, int echo);
                     35: void input_userauth_info_response(int type, int plen, void *ctxt);
                     36:
                     37: /*
                     38:  * try challenge-reponse, return -1 (= postponed) if we have to
                     39:  * wait for the response.
                     40:  */
                     41: int
                     42: auth2_challenge(Authctxt *authctxt, char *devs)
                     43: {
                     44:        char *challenge;
                     45:
                     46:        if (!authctxt->valid || authctxt->user == NULL)
                     47:                return 0;
                     48:        if ((challenge = get_challenge(authctxt, devs)) == NULL)
                     49:                return 0;
                     50:        send_userauth_into_request(authctxt, challenge, 0);
                     51:        dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE,
                     52:            &input_userauth_info_response);
                     53:        authctxt->postponed = 1;
                     54:        return 0;
                     55: }
                     56:
                     57: void
                     58: send_userauth_into_request(Authctxt *authctxt, char *challenge, int echo)
                     59: {
                     60:        int nprompts = 1;
                     61:
                     62:        packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
                     63:        /* name, instruction and language are unused */
                     64:        packet_put_cstring("");
                     65:        packet_put_cstring("");
                     66:        packet_put_cstring("");
                     67:        packet_put_int(nprompts);
                     68:        packet_put_cstring(challenge);
                     69:        packet_put_char(echo);
                     70:        packet_send();
                     71:        packet_write_wait();
                     72: }
                     73:
                     74: void
                     75: input_userauth_info_response(int type, int plen, void *ctxt)
                     76: {
                     77:        Authctxt *authctxt = ctxt;
                     78:        int authenticated = 0;
                     79:        u_int nresp, rlen;
                     80:        char *response, *method = "challenge-reponse";
                     81:
                     82:        if (authctxt == NULL)
                     83:                fatal("input_userauth_info_response: no authctxt");
                     84:
                     85:        authctxt->postponed = 0;        /* reset */
                     86:        nresp = packet_get_int();
                     87:        if (nresp == 1) {
                     88:                response = packet_get_string(&rlen);
                     89:                packet_done();
                     90:                if (strlen(response) == 0) {
                     91:                        /*
                     92:                         * if we received an empty response, resend challenge
                     93:                         * with echo enabled
                     94:                         */
                     95:                        char *challenge = get_challenge(authctxt, NULL);
                     96:                        if (challenge != NULL) {
                     97:                                send_userauth_into_request(authctxt,
                     98:                                    challenge, 1);
                     99:                                authctxt->postponed = 1;
                    100:                        }
                    101:                } else if (authctxt->valid) {
                    102:                        authenticated = verify_response(authctxt, response);
                    103:                        memset(response, 'r', rlen);
                    104:                }
                    105:                xfree(response);
                    106:        }
                    107:        auth_log(authctxt, authenticated, method, " ssh2");
                    108:        if (!authctxt->postponed) {
                    109:                /* unregister callback and send reply */
                    110:                dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, NULL);
                    111:                userauth_reply(authctxt, authenticated);
                    112:        }
                    113: }