=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/auth2-chall.c,v retrieving revision 1.2.2.7 retrieving revision 1.3 diff -u -r1.2.2.7 -r1.3 --- src/usr.bin/ssh/auth2-chall.c 2002/03/08 17:04:41 1.2.2.7 +++ src/usr.bin/ssh/auth2-chall.c 2001/03/02 18:54:31 1.3 @@ -1,6 +1,5 @@ /* * Copyright (c) 2001 Markus Friedl. All rights reserved. - * Copyright (c) 2001 Per Allansson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -23,290 +22,92 @@ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "includes.h" -RCSID("$OpenBSD: auth2-chall.c,v 1.2.2.7 2002/03/08 17:04:41 brad Exp $"); +RCSID("$OpenBSD: auth2-chall.c,v 1.3 2001/03/02 18:54:31 deraadt Exp $"); #include "ssh2.h" #include "auth.h" -#include "buffer.h" #include "packet.h" #include "xmalloc.h" #include "dispatch.h" -#include "auth.h" #include "log.h" -static int auth2_challenge_start(Authctxt *); -static int send_userauth_info_request(Authctxt *); -static void input_userauth_info_response(int, u_int32_t, void *); +void send_userauth_into_request(Authctxt *authctxt, char *challenge, int echo); +void input_userauth_info_response(int type, int plen, void *ctxt); -#ifdef BSD_AUTH -extern KbdintDevice bsdauth_device; -#else -#ifdef SKEY -extern KbdintDevice skey_device; -#endif -#endif - -KbdintDevice *devices[] = { -#ifdef BSD_AUTH - &bsdauth_device, -#else -#ifdef SKEY - &skey_device, -#endif -#endif - NULL -}; - -typedef struct KbdintAuthctxt KbdintAuthctxt; -struct KbdintAuthctxt -{ - char *devices; - void *ctxt; - KbdintDevice *device; -}; - -static KbdintAuthctxt * -kbdint_alloc(const char *devs) -{ - KbdintAuthctxt *kbdintctxt; - Buffer b; - int i; - - kbdintctxt = xmalloc(sizeof(KbdintAuthctxt)); - if (strcmp(devs, "") == 0) { - buffer_init(&b); - for (i = 0; devices[i]; i++) { - if (buffer_len(&b) > 0) - buffer_append(&b, ",", 1); - buffer_append(&b, devices[i]->name, - strlen(devices[i]->name)); - } - buffer_append(&b, "\0", 1); - kbdintctxt->devices = xstrdup(buffer_ptr(&b)); - buffer_free(&b); - } else { - kbdintctxt->devices = xstrdup(devs); - } - debug("kbdint_alloc: devices '%s'", kbdintctxt->devices); - kbdintctxt->ctxt = NULL; - kbdintctxt->device = NULL; - - return kbdintctxt; -} -static void -kbdint_reset_device(KbdintAuthctxt *kbdintctxt) -{ - if (kbdintctxt->ctxt) { - kbdintctxt->device->free_ctx(kbdintctxt->ctxt); - kbdintctxt->ctxt = NULL; - } - kbdintctxt->device = NULL; -} -static void -kbdint_free(KbdintAuthctxt *kbdintctxt) -{ - if (kbdintctxt->device) - kbdint_reset_device(kbdintctxt); - if (kbdintctxt->devices) { - xfree(kbdintctxt->devices); - kbdintctxt->devices = NULL; - } - xfree(kbdintctxt); -} -/* get next device */ -static int -kbdint_next_device(KbdintAuthctxt *kbdintctxt) -{ - size_t len; - char *t; - int i; - - if (kbdintctxt->device) - kbdint_reset_device(kbdintctxt); - do { - len = kbdintctxt->devices ? - strcspn(kbdintctxt->devices, ",") : 0; - - if (len == 0) - break; - for (i = 0; devices[i]; i++) - if (strncmp(kbdintctxt->devices, devices[i]->name, len) == 0) - kbdintctxt->device = devices[i]; - t = kbdintctxt->devices; - kbdintctxt->devices = t[len] ? xstrdup(t+len+1) : NULL; - xfree(t); - debug2("kbdint_next_device: devices %s", kbdintctxt->devices ? - kbdintctxt->devices : ""); - } while (kbdintctxt->devices && !kbdintctxt->device); - - return kbdintctxt->device ? 1 : 0; -} - /* - * try challenge-response, set authctxt->postponed if we have to + * try challenge-reponse, return -1 (= postponed) if we have to * wait for the response. */ int auth2_challenge(Authctxt *authctxt, char *devs) { - debug("auth2_challenge: user=%s devs=%s", - authctxt->user ? authctxt->user : "", - devs ? devs : ""); + char *challenge; - if (authctxt->user == NULL || !devs) + if (!authctxt->valid || authctxt->user == NULL) return 0; - if (authctxt->kbdintctxt == NULL) - authctxt->kbdintctxt = kbdint_alloc(devs); - return auth2_challenge_start(authctxt); -} - -/* unregister kbd-int callbacks and context */ -void -auth2_challenge_stop(Authctxt *authctxt) -{ - /* unregister callback */ - dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, NULL); - if (authctxt->kbdintctxt != NULL) { - kbdint_free(authctxt->kbdintctxt); - authctxt->kbdintctxt = NULL; - } -} - -/* side effect: sets authctxt->postponed if a reply was sent*/ -static int -auth2_challenge_start(Authctxt *authctxt) -{ - KbdintAuthctxt *kbdintctxt = authctxt->kbdintctxt; - - debug2("auth2_challenge_start: devices %s", - kbdintctxt->devices ? kbdintctxt->devices : ""); - - if (kbdint_next_device(kbdintctxt) == 0) { - auth2_challenge_stop(authctxt); + if ((challenge = get_challenge(authctxt, devs)) == NULL) return 0; - } - debug("auth2_challenge_start: trying authentication method '%s'", - kbdintctxt->device->name); - - if ((kbdintctxt->ctxt = kbdintctxt->device->init_ctx(authctxt)) == NULL) { - auth2_challenge_stop(authctxt); - return 0; - } - if (send_userauth_info_request(authctxt) == 0) { - auth2_challenge_stop(authctxt); - 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; } -static int -send_userauth_info_request(Authctxt *authctxt) +void +send_userauth_into_request(Authctxt *authctxt, char *challenge, int echo) { - KbdintAuthctxt *kbdintctxt; - char *name, *instr, **prompts; - int i; - u_int numprompts, *echo_on; + int nprompts = 1; - kbdintctxt = authctxt->kbdintctxt; - if (kbdintctxt->device->query(kbdintctxt->ctxt, - &name, &instr, &numprompts, &prompts, &echo_on)) - return 0; - packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST); - packet_put_cstring(name); - packet_put_cstring(instr); - packet_put_cstring(""); /* language not used */ - packet_put_int(numprompts); - for (i = 0; i < numprompts; i++) { - packet_put_cstring(prompts[i]); - packet_put_char(echo_on[i]); - } + /* 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(); - - for (i = 0; i < numprompts; i++) - xfree(prompts[i]); - xfree(prompts); - xfree(echo_on); - xfree(name); - xfree(instr); - return 1; } -static void -input_userauth_info_response(int type, u_int32_t seq, void *ctxt) +void +input_userauth_info_response(int type, int plen, void *ctxt) { Authctxt *authctxt = ctxt; - KbdintAuthctxt *kbdintctxt; - int i, authenticated = 0, res, len; - u_int nresp; - char **response = NULL, *method; + int authenticated = 0; + u_int nresp, rlen; + char *response, *method = "challenge-reponse"; if (authctxt == NULL) fatal("input_userauth_info_response: no authctxt"); - kbdintctxt = authctxt->kbdintctxt; - if (kbdintctxt == NULL || kbdintctxt->ctxt == NULL) - fatal("input_userauth_info_response: no kbdintctxt"); - if (kbdintctxt->device == NULL) - fatal("input_userauth_info_response: no device"); authctxt->postponed = 0; /* reset */ nresp = packet_get_int(); - if (nresp > 0) { - response = xmalloc(nresp * sizeof(char*)); - for (i = 0; i < nresp; i++) - response[i] = packet_get_string(NULL); - } - packet_check_eom(); - - if (authctxt->valid) { - res = kbdintctxt->device->respond(kbdintctxt->ctxt, - nresp, response); - } else { - res = -1; - } - - for (i = 0; i < nresp; i++) { - memset(response[i], 'r', strlen(response[i])); - xfree(response[i]); - } - if (response) + 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); - - switch (res) { - case 0: - /* Success! */ - authenticated = 1; - break; - case 1: - /* Authentication needs further interaction */ - if (send_userauth_info_request(authctxt) == 1) - authctxt->postponed = 1; - break; - default: - /* Failure! */ - break; } - - len = strlen("keyboard-interactive") + 2 + - strlen(kbdintctxt->device->name); - method = xmalloc(len); - snprintf(method, len, "keyboard-interactive/%s", - kbdintctxt->device->name); - + auth_log(authctxt, authenticated, method, " ssh2"); if (!authctxt->postponed) { - if (authenticated) { - auth2_challenge_stop(authctxt); - } else { - /* start next device */ - /* may set authctxt->postponed */ - auth2_challenge_start(authctxt); - } + /* unregister callback and send reply */ + dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, NULL); + userauth_reply(authctxt, authenticated); } - userauth_finish(authctxt, authenticated, method); - xfree(method); }