diff options
Diffstat (limited to 'auth2-chall.c')
| -rw-r--r-- | auth2-chall.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/auth2-chall.c b/auth2-chall.c new file mode 100644 index 00000000..77294f4b --- /dev/null +++ b/auth2-chall.c @@ -0,0 +1,113 @@ +/* + * Copyright (c) 2001 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +#include "includes.h" +RCSID("$OpenBSD: auth2-chall.c,v 1.1 2001/01/18 17:12:43 markus Exp $"); + +#include "ssh.h" +#include "ssh2.h" +#include "auth.h" +#include "packet.h" +#include "xmalloc.h" +#include "dispatch.h" + +void send_userauth_into_request(Authctxt *authctxt, char *challenge, int echo); +void input_userauth_info_response(int type, int plen, void *ctxt); + +/* + * try challenge-reponse, return -1 (= postponed) if we have to + * wait for the response. + */ +int +auth2_challenge(Authctxt *authctxt, char *devs) +{ + char *challenge; + + if (!authctxt->valid || authctxt->user == NULL) + return 0; + if ((challenge = get_challenge(authctxt, devs)) == NULL) + return 0; + send_userauth_into_request(authctxt, challenge, 0); + dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, + &input_userauth_info_response); + authctxt->postponed = 1; + return 0; +} + +void +send_userauth_into_request(Authctxt *authctxt, char *challenge, int echo) +{ + int nprompts = 1; + + packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST); + /* name, instruction and language are unused */ + packet_put_cstring(""); + packet_put_cstring(""); + packet_put_cstring(""); + packet_put_int(nprompts); + packet_put_cstring(challenge); + packet_put_char(echo); + packet_send(); + packet_write_wait(); +} + +void +input_userauth_info_response(int type, int plen, void *ctxt) +{ + Authctxt *authctxt = ctxt; + int authenticated = 0; + u_int nresp, rlen; + char *response, *method = "challenge-reponse"; + + if (authctxt == NULL) + fatal("input_userauth_info_response: no authctxt"); + + authctxt->postponed = 0; /* reset */ + nresp = packet_get_int(); + if (nresp == 1) { + response = packet_get_string(&rlen); + packet_done(); + if (strlen(response) == 0) { + /* + * if we received an empty response, resend challenge + * with echo enabled + */ + char *challenge = get_challenge(authctxt, NULL); + if (challenge != NULL) { + send_userauth_into_request(authctxt, + challenge, 1); + authctxt->postponed = 1; + } + } else if (authctxt->valid) { + authenticated = verify_response(authctxt, response); + memset(response, 'r', rlen); + } + xfree(response); + } + auth_log(authctxt, authenticated, method, " ssh2"); + if (!authctxt->postponed) { + /* unregister callback and send reply */ + dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, NULL); + userauth_reply(authctxt, authenticated); + } +} |