1323136Sdes/* $OpenBSD: sshconnect2.c,v 1.255 2017/03/11 23:40:26 djm Exp $ */ 260573Skris/* 360573Skris * Copyright (c) 2000 Markus Friedl. All rights reserved. 4192595Sdes * Copyright (c) 2008 Damien Miller. All rights reserved. 560573Skris * 660573Skris * Redistribution and use in source and binary forms, with or without 760573Skris * modification, are permitted provided that the following conditions 860573Skris * are met: 960573Skris * 1. Redistributions of source code must retain the above copyright 1060573Skris * notice, this list of conditions and the following disclaimer. 1160573Skris * 2. Redistributions in binary form must reproduce the above copyright 1260573Skris * notice, this list of conditions and the following disclaimer in the 1360573Skris * documentation and/or other materials provided with the distribution. 1460573Skris * 1560573Skris * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1660573Skris * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1760573Skris * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1860573Skris * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 1960573Skris * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 2060573Skris * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2160573Skris * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2260573Skris * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2360573Skris * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2460573Skris * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2560573Skris */ 2660573Skris 2760573Skris#include "includes.h" 2860573Skris 29162856Sdes#include <sys/types.h> 30162856Sdes#include <sys/socket.h> 31162856Sdes#include <sys/wait.h> 32162856Sdes#include <sys/stat.h> 33162856Sdes 34162856Sdes#include <errno.h> 35204917Sdes#include <fcntl.h> 36181111Sdes#include <netdb.h> 37162856Sdes#include <pwd.h> 38162856Sdes#include <signal.h> 39162856Sdes#include <stdarg.h> 40162856Sdes#include <stdio.h> 41162856Sdes#include <string.h> 42162856Sdes#include <unistd.h> 43248619Sdes#if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS) 44181111Sdes#include <vis.h> 45181111Sdes#endif 46162856Sdes 47124211Sdes#include "openbsd-compat/sys-queue.h" 48124211Sdes 49162856Sdes#include "xmalloc.h" 5060573Skris#include "ssh.h" 5176262Sgreen#include "ssh2.h" 5260573Skris#include "buffer.h" 5360573Skris#include "packet.h" 5460573Skris#include "compat.h" 5576262Sgreen#include "cipher.h" 56162856Sdes#include "key.h" 5760573Skris#include "kex.h" 5860573Skris#include "myproposal.h" 5960573Skris#include "sshconnect.h" 6060573Skris#include "authfile.h" 6176262Sgreen#include "dh.h" 6276262Sgreen#include "authfd.h" 6376262Sgreen#include "log.h" 64294328Sdes#include "misc.h" 6576262Sgreen#include "readconf.h" 6676262Sgreen#include "match.h" 6769587Sgreen#include "dispatch.h" 6876262Sgreen#include "canohost.h" 6998684Sdes#include "msg.h" 7098684Sdes#include "pathnames.h" 71162856Sdes#include "uidswap.h" 72221420Sdes#include "hostfile.h" 73294332Sdes#include "ssherr.h" 74323129Sdes#include "utf8.h" 7560573Skris 76124211Sdes#ifdef GSSAPI 77124211Sdes#include "ssh-gss.h" 78124211Sdes#endif 79124211Sdes 8060573Skris/* import */ 8160573Skrisextern char *client_version_string; 8260573Skrisextern char *server_version_string; 8360573Skrisextern Options options; 8460573Skris 8560573Skris/* 8660573Skris * SSH2 key exchange 8760573Skris */ 8860573Skris 8976262Sgreenu_char *session_id2 = NULL; 90124211Sdesu_int session_id2_len = 0; 9160573Skris 9276262Sgreenchar *xxx_host; 9376262Sgreenstruct sockaddr *xxx_hostaddr; 9476262Sgreen 9592559Sdesstatic int 96294332Sdesverify_host_key_callback(Key *hostkey, struct ssh *ssh) 9776262Sgreen{ 9892559Sdes if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) 9992559Sdes fatal("Host key verification failed."); 10076262Sgreen return 0; 10176262Sgreen} 10276262Sgreen 103221420Sdesstatic char * 104221420Sdesorder_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port) 105221420Sdes{ 106221420Sdes char *oavail, *avail, *first, *last, *alg, *hostname, *ret; 107221420Sdes size_t maxlen; 108221420Sdes struct hostkeys *hostkeys; 109221420Sdes int ktype; 110226046Sdes u_int i; 111221420Sdes 112221420Sdes /* Find all hostkeys for this hostname */ 113221420Sdes get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL); 114221420Sdes hostkeys = init_hostkeys(); 115226046Sdes for (i = 0; i < options.num_user_hostfiles; i++) 116226046Sdes load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]); 117226046Sdes for (i = 0; i < options.num_system_hostfiles; i++) 118226046Sdes load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]); 119221420Sdes 120221420Sdes oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG); 121221420Sdes maxlen = strlen(avail) + 1; 122221420Sdes first = xmalloc(maxlen); 123221420Sdes last = xmalloc(maxlen); 124221420Sdes *first = *last = '\0'; 125221420Sdes 126221420Sdes#define ALG_APPEND(to, from) \ 127221420Sdes do { \ 128221420Sdes if (*to != '\0') \ 129221420Sdes strlcat(to, ",", maxlen); \ 130221420Sdes strlcat(to, from, maxlen); \ 131221420Sdes } while (0) 132221420Sdes 133221420Sdes while ((alg = strsep(&avail, ",")) && *alg != '\0') { 134294332Sdes if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC) 135221420Sdes fatal("%s: unknown alg %s", __func__, alg); 136221420Sdes if (lookup_key_in_hostkeys_by_type(hostkeys, 137294332Sdes sshkey_type_plain(ktype), NULL)) 138221420Sdes ALG_APPEND(first, alg); 139221420Sdes else 140221420Sdes ALG_APPEND(last, alg); 141221420Sdes } 142221420Sdes#undef ALG_APPEND 143294332Sdes xasprintf(&ret, "%s%s%s", first, 144294332Sdes (*first == '\0' || *last == '\0') ? "" : ",", last); 145221420Sdes if (*first != '\0') 146221420Sdes debug3("%s: prefer hostkeyalgs: %s", __func__, first); 147221420Sdes 148255767Sdes free(first); 149255767Sdes free(last); 150255767Sdes free(hostname); 151255767Sdes free(oavail); 152221420Sdes free_hostkeys(hostkeys); 153221420Sdes 154221420Sdes return ret; 155221420Sdes} 156221420Sdes 15760573Skrisvoid 158221420Sdesssh_kex2(char *host, struct sockaddr *hostaddr, u_short port) 15960573Skris{ 160294328Sdes char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT }; 161296633Sdes char *s; 162294332Sdes struct kex *kex; 163294332Sdes int r; 16469587Sgreen 16576262Sgreen xxx_host = host; 16676262Sgreen xxx_hostaddr = hostaddr; 16776262Sgreen 168296633Sdes if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL) 169296633Sdes fatal("%s: kex_names_cat", __func__); 170296633Sdes myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(s); 17176262Sgreen myproposal[PROPOSAL_ENC_ALGS_CTOS] = 172294464Sdes compat_cipher_proposal(options.ciphers); 17376262Sgreen myproposal[PROPOSAL_ENC_ALGS_STOC] = 174294464Sdes compat_cipher_proposal(options.ciphers); 175323129Sdes myproposal[PROPOSAL_COMP_ALGS_CTOS] = 176323129Sdes myproposal[PROPOSAL_COMP_ALGS_STOC] = options.compression ? 177323129Sdes "zlib@openssh.com,zlib,none" : "none,zlib@openssh.com,zlib"; 178294464Sdes myproposal[PROPOSAL_MAC_ALGS_CTOS] = 179294464Sdes myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; 180294464Sdes if (options.hostkeyalgorithms != NULL) { 181294464Sdes if (kex_assemble_names(KEX_DEFAULT_PK_ALG, 182294464Sdes &options.hostkeyalgorithms) != 0) 183294464Sdes fatal("%s: kex_assemble_namelist", __func__); 18492559Sdes myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = 185261320Sdes compat_pkalg_proposal(options.hostkeyalgorithms); 186294464Sdes } else { 187294464Sdes /* Enforce default */ 188294464Sdes options.hostkeyalgorithms = xstrdup(KEX_DEFAULT_PK_ALG); 189221420Sdes /* Prefer algorithms that we already have keys for */ 190221420Sdes myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = 191261320Sdes compat_pkalg_proposal( 192261320Sdes order_hostkeyalgs(host, hostaddr, port)); 193221420Sdes } 19469587Sgreen 195255767Sdes if (options.rekey_limit || options.rekey_interval) 196323136Sdes packet_set_rekey_limits(options.rekey_limit, 197323136Sdes options.rekey_interval); 198124211Sdes 19976262Sgreen /* start key exchange */ 200294332Sdes if ((r = kex_setup(active_state, myproposal)) != 0) 201294332Sdes fatal("kex_setup: %s", ssh_err(r)); 202294332Sdes kex = active_state->kex; 203294328Sdes#ifdef WITH_OPENSSL 204113911Sdes kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; 205137019Sdes kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client; 206323129Sdes kex->kex[KEX_DH_GRP14_SHA256] = kexdh_client; 207323129Sdes kex->kex[KEX_DH_GRP16_SHA512] = kexdh_client; 208323129Sdes kex->kex[KEX_DH_GRP18_SHA512] = kexdh_client; 209113911Sdes kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; 210162856Sdes kex->kex[KEX_DH_GEX_SHA256] = kexgex_client; 211294332Sdes# ifdef OPENSSL_HAS_ECC 212221420Sdes kex->kex[KEX_ECDH_SHA2] = kexecdh_client; 213294332Sdes# endif 214294328Sdes#endif 215261320Sdes kex->kex[KEX_C25519_SHA256] = kexc25519_client; 21676262Sgreen kex->client_version_string=client_version_string; 21776262Sgreen kex->server_version_string=server_version_string; 21892559Sdes kex->verify_host_key=&verify_host_key_callback; 21969587Sgreen 220294332Sdes dispatch_run(DISPATCH_BLOCK, &kex->done, active_state); 22169587Sgreen 222296633Sdes /* remove ext-info from the KEX proposals for rekeying */ 223296633Sdes myproposal[PROPOSAL_KEX_ALGS] = 224296633Sdes compat_kex_proposal(options.kex_algorithms); 225296633Sdes if ((r = kex_prop2buf(kex->my, myproposal)) != 0) 226296633Sdes fatal("kex_prop2buf: %s", ssh_err(r)); 227204917Sdes 22876262Sgreen session_id2 = kex->session_id; 22976262Sgreen session_id2_len = kex->session_id_len; 23069587Sgreen 23169587Sgreen#ifdef DEBUG_KEXDH 23269587Sgreen /* send 1st encrypted/maced/compressed message */ 23369587Sgreen packet_start(SSH2_MSG_IGNORE); 23469587Sgreen packet_put_cstring("markus"); 23569587Sgreen packet_send(); 23669587Sgreen packet_write_wait(); 23769587Sgreen#endif 23869587Sgreen} 23969587Sgreen 24069587Sgreen/* 24160573Skris * Authenticate user 24260573Skris */ 24369587Sgreen 244294332Sdestypedef struct cauthctxt Authctxt; 245294332Sdestypedef struct cauthmethod Authmethod; 246124211Sdestypedef struct identity Identity; 247124211Sdestypedef struct idlist Idlist; 24869587Sgreen 249124211Sdesstruct identity { 250124211Sdes TAILQ_ENTRY(identity) next; 251294332Sdes int agent_fd; /* >=0 if agent supports key */ 252294332Sdes struct sshkey *key; /* public/private key */ 253124211Sdes char *filename; /* comment for agent-only keys */ 254124211Sdes int tried; 255124211Sdes int isprivate; /* key points to the private key */ 256248619Sdes int userprovided; 257124211Sdes}; 258124211SdesTAILQ_HEAD(idlist, identity); 25969587Sgreen 260294332Sdesstruct cauthctxt { 26169587Sgreen const char *server_user; 26276262Sgreen const char *local_user; 26369587Sgreen const char *host; 26469587Sgreen const char *service; 265294332Sdes struct cauthmethod *method; 266215116Sdes sig_atomic_t success; 26776262Sgreen char *authlist; 268294332Sdes int attempt; 26976262Sgreen /* pubkey */ 270294332Sdes struct idlist keys; 271294332Sdes int agent_fd; 27276262Sgreen /* hostbased */ 27398684Sdes Sensitive *sensitive; 274294332Sdes char *oktypes, *ktypes; 275294332Sdes const char *active_ktype; 27692559Sdes /* kbd-interactive */ 27792559Sdes int info_req_seen; 278124211Sdes /* generic */ 279124211Sdes void *methoddata; 28069587Sgreen}; 281294332Sdes 282294332Sdesstruct cauthmethod { 28369587Sgreen char *name; /* string to compare against server's list */ 28469587Sgreen int (*userauth)(Authctxt *authctxt); 285192595Sdes void (*cleanup)(Authctxt *authctxt); 28669587Sgreen int *enabled; /* flag in option struct that enables method */ 28769587Sgreen int *batch_flag; /* flag in option struct that disables method */ 28869587Sgreen}; 28969587Sgreen 290296633Sdesint input_userauth_service_accept(int, u_int32_t, void *); 291296633Sdesint input_userauth_ext_info(int, u_int32_t, void *); 292294332Sdesint input_userauth_success(int, u_int32_t, void *); 293294332Sdesint input_userauth_success_unexpected(int, u_int32_t, void *); 294294332Sdesint input_userauth_failure(int, u_int32_t, void *); 295294332Sdesint input_userauth_banner(int, u_int32_t, void *); 296294332Sdesint input_userauth_error(int, u_int32_t, void *); 297294332Sdesint input_userauth_info_req(int, u_int32_t, void *); 298294332Sdesint input_userauth_pk_ok(int, u_int32_t, void *); 299294332Sdesint input_userauth_passwd_changereq(int, u_int32_t, void *); 30069587Sgreen 30192559Sdesint userauth_none(Authctxt *); 30292559Sdesint userauth_pubkey(Authctxt *); 30392559Sdesint userauth_passwd(Authctxt *); 30492559Sdesint userauth_kbdint(Authctxt *); 30592559Sdesint userauth_hostbased(Authctxt *); 30669587Sgreen 307124211Sdes#ifdef GSSAPI 308124211Sdesint userauth_gssapi(Authctxt *authctxt); 309294332Sdesint input_gssapi_response(int type, u_int32_t, void *); 310294332Sdesint input_gssapi_token(int type, u_int32_t, void *); 311294332Sdesint input_gssapi_hash(int type, u_int32_t, void *); 312294332Sdesint input_gssapi_error(int, u_int32_t, void *); 313294332Sdesint input_gssapi_errtok(int, u_int32_t, void *); 314124211Sdes#endif 315124211Sdes 31692559Sdesvoid userauth(Authctxt *, char *); 31776262Sgreen 318124211Sdesstatic int sign_and_send_pubkey(Authctxt *, Identity *); 319124211Sdesstatic void pubkey_prepare(Authctxt *); 320124211Sdesstatic void pubkey_cleanup(Authctxt *); 321323134Sdesstatic void pubkey_reset(Authctxt *); 322296633Sdesstatic Key *load_identity_file(Identity *); 32376262Sgreen 32492559Sdesstatic Authmethod *authmethod_get(char *authlist); 32592559Sdesstatic Authmethod *authmethod_lookup(const char *name); 32692559Sdesstatic char *authmethods_get(void); 32769587Sgreen 32869587SgreenAuthmethod authmethods[] = { 329124211Sdes#ifdef GSSAPI 330126277Sdes {"gssapi-with-mic", 331124211Sdes userauth_gssapi, 332192595Sdes NULL, 333124211Sdes &options.gss_authentication, 334124211Sdes NULL}, 335124211Sdes#endif 33692559Sdes {"hostbased", 33792559Sdes userauth_hostbased, 338192595Sdes NULL, 33992559Sdes &options.hostbased_authentication, 34092559Sdes NULL}, 34169587Sgreen {"publickey", 34269587Sgreen userauth_pubkey, 343192595Sdes NULL, 34476262Sgreen &options.pubkey_authentication, 34569587Sgreen NULL}, 34692559Sdes {"keyboard-interactive", 34792559Sdes userauth_kbdint, 348192595Sdes NULL, 34992559Sdes &options.kbd_interactive_authentication, 35092559Sdes &options.batch_mode}, 35169587Sgreen {"password", 35269587Sgreen userauth_passwd, 353192595Sdes NULL, 35469587Sgreen &options.password_authentication, 35569587Sgreen &options.batch_mode}, 35669587Sgreen {"none", 35769587Sgreen userauth_none, 35869587Sgreen NULL, 359192595Sdes NULL, 36069587Sgreen NULL}, 361192595Sdes {NULL, NULL, NULL, NULL, NULL} 36269587Sgreen}; 36369587Sgreen 36469587Sgreenvoid 36576262Sgreenssh_userauth2(const char *local_user, const char *server_user, char *host, 36698684Sdes Sensitive *sensitive) 36769587Sgreen{ 368296633Sdes struct ssh *ssh = active_state; 36969587Sgreen Authctxt authctxt; 370296633Sdes int r; 37169587Sgreen 37292559Sdes if (options.challenge_response_authentication) 37376262Sgreen options.kbd_interactive_authentication = 1; 37476262Sgreen if (options.preferred_authentications == NULL) 37576262Sgreen options.preferred_authentications = authmethods_get(); 37676262Sgreen 37769587Sgreen /* setup authentication context */ 37892559Sdes memset(&authctxt, 0, sizeof(authctxt)); 379124211Sdes pubkey_prepare(&authctxt); 38069587Sgreen authctxt.server_user = server_user; 38176262Sgreen authctxt.local_user = local_user; 38269587Sgreen authctxt.host = host; 38369587Sgreen authctxt.service = "ssh-connection"; /* service name */ 38469587Sgreen authctxt.success = 0; 38569587Sgreen authctxt.method = authmethod_lookup("none"); 38676262Sgreen authctxt.authlist = NULL; 387124211Sdes authctxt.methoddata = NULL; 38898684Sdes authctxt.sensitive = sensitive; 389294332Sdes authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL; 39092559Sdes authctxt.info_req_seen = 0; 391294332Sdes authctxt.agent_fd = -1; 39269587Sgreen if (authctxt.method == NULL) 39369587Sgreen fatal("ssh_userauth2: internal error: cannot send userauth none request"); 39469587Sgreen 395296633Sdes if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 || 396296633Sdes (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 || 397296633Sdes (r = sshpkt_send(ssh)) != 0) 398296633Sdes fatal("%s: %s", __func__, ssh_err(r)); 39969587Sgreen 400296633Sdes ssh_dispatch_init(ssh, &input_userauth_error); 401296633Sdes ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info); 402296633Sdes ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept); 403296633Sdes ssh_dispatch_run(ssh, DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ 40469587Sgreen 405124211Sdes pubkey_cleanup(&authctxt); 406296633Sdes ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); 40769587Sgreen 408323134Sdes if (!authctxt.success) 409323134Sdes fatal("Authentication failed."); 410113911Sdes debug("Authentication succeeded (%s).", authctxt.method->name); 41169587Sgreen} 412124211Sdes 413296633Sdes/* ARGSUSED */ 414296633Sdesint 415296633Sdesinput_userauth_service_accept(int type, u_int32_t seqnr, void *ctxt) 416296633Sdes{ 417296633Sdes Authctxt *authctxt = ctxt; 418296633Sdes struct ssh *ssh = active_state; 419296633Sdes int r; 420296633Sdes 421296633Sdes if (ssh_packet_remaining(ssh) > 0) { 422296633Sdes char *reply; 423296633Sdes 424296633Sdes if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0) 425296633Sdes goto out; 426296633Sdes debug2("service_accept: %s", reply); 427296633Sdes free(reply); 428296633Sdes } else { 429296633Sdes debug2("buggy server: service_accept w/o service"); 430296633Sdes } 431296633Sdes if ((r = sshpkt_get_end(ssh)) != 0) 432296633Sdes goto out; 433296633Sdes debug("SSH2_MSG_SERVICE_ACCEPT received"); 434296633Sdes 435296633Sdes /* initial userauth request */ 436296633Sdes userauth_none(authctxt); 437296633Sdes 438296633Sdes ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error); 439296633Sdes ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); 440296633Sdes ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); 441296633Sdes ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); 442296633Sdes r = 0; 443296633Sdes out: 444296633Sdes return r; 445296633Sdes} 446296633Sdes 447296633Sdes/* ARGSUSED */ 448296633Sdesint 449296633Sdesinput_userauth_ext_info(int type, u_int32_t seqnr, void *ctxt) 450296633Sdes{ 451296633Sdes return kex_input_ext_info(type, seqnr, active_state); 452296633Sdes} 453296633Sdes 45469587Sgreenvoid 45576262Sgreenuserauth(Authctxt *authctxt, char *authlist) 45676262Sgreen{ 457192595Sdes if (authctxt->method != NULL && authctxt->method->cleanup != NULL) 458192595Sdes authctxt->method->cleanup(authctxt); 459192595Sdes 460255767Sdes free(authctxt->methoddata); 461255767Sdes authctxt->methoddata = NULL; 46276262Sgreen if (authlist == NULL) { 46376262Sgreen authlist = authctxt->authlist; 46476262Sgreen } else { 465255767Sdes free(authctxt->authlist); 46676262Sgreen authctxt->authlist = authlist; 46776262Sgreen } 46876262Sgreen for (;;) { 46976262Sgreen Authmethod *method = authmethod_get(authlist); 47076262Sgreen if (method == NULL) 47176262Sgreen fatal("Permission denied (%s).", authlist); 47276262Sgreen authctxt->method = method; 473124211Sdes 474124211Sdes /* reset the per method handler */ 475124211Sdes dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, 476124211Sdes SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); 477124211Sdes 478124211Sdes /* and try new method */ 47976262Sgreen if (method->userauth(authctxt) != 0) { 48076262Sgreen debug2("we sent a %s packet, wait for reply", method->name); 48176262Sgreen break; 48276262Sgreen } else { 48376262Sgreen debug2("we did not send a packet, disable method"); 48476262Sgreen method->enabled = NULL; 48576262Sgreen } 48676262Sgreen } 48776262Sgreen} 48899063Sdes 489192595Sdes/* ARGSUSED */ 490294332Sdesint 49192559Sdesinput_userauth_error(int type, u_int32_t seq, void *ctxt) 49269587Sgreen{ 49376262Sgreen fatal("input_userauth_error: bad message during authentication: " 494149753Sdes "type %d", type); 495294332Sdes return 0; 49669587Sgreen} 49799063Sdes 498192595Sdes/* ARGSUSED */ 499294332Sdesint 50092559Sdesinput_userauth_banner(int type, u_int32_t seq, void *ctxt) 50176262Sgreen{ 502323129Sdes char *msg, *lang; 503181111Sdes u_int len; 504126277Sdes 505323129Sdes debug3("%s", __func__); 506323129Sdes msg = packet_get_string(&len); 50776262Sgreen lang = packet_get_string(NULL); 508323129Sdes if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) 509323129Sdes fmprintf(stderr, "%s", msg); 510323129Sdes free(msg); 511255767Sdes free(lang); 512294332Sdes return 0; 51376262Sgreen} 51499063Sdes 515192595Sdes/* ARGSUSED */ 516294332Sdesint 51792559Sdesinput_userauth_success(int type, u_int32_t seq, void *ctxt) 51869587Sgreen{ 51969587Sgreen Authctxt *authctxt = ctxt; 520204917Sdes 52169587Sgreen if (authctxt == NULL) 52269587Sgreen fatal("input_userauth_success: no authentication context"); 523255767Sdes free(authctxt->authlist); 524255767Sdes authctxt->authlist = NULL; 525204917Sdes if (authctxt->method != NULL && authctxt->method->cleanup != NULL) 526204917Sdes authctxt->method->cleanup(authctxt); 527255767Sdes free(authctxt->methoddata); 528255767Sdes authctxt->methoddata = NULL; 52969587Sgreen authctxt->success = 1; /* break out */ 530294332Sdes return 0; 53169587Sgreen} 53299063Sdes 533294332Sdesint 534204917Sdesinput_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt) 535204917Sdes{ 536204917Sdes Authctxt *authctxt = ctxt; 537204917Sdes 538204917Sdes if (authctxt == NULL) 539204917Sdes fatal("%s: no authentication context", __func__); 540204917Sdes 541204917Sdes fatal("Unexpected authentication success during %s.", 542204917Sdes authctxt->method->name); 543294332Sdes return 0; 544204917Sdes} 545204917Sdes 546192595Sdes/* ARGSUSED */ 547294332Sdesint 54892559Sdesinput_userauth_failure(int type, u_int32_t seq, void *ctxt) 54969587Sgreen{ 55069587Sgreen Authctxt *authctxt = ctxt; 55169587Sgreen char *authlist = NULL; 55269587Sgreen int partial; 55369587Sgreen 55469587Sgreen if (authctxt == NULL) 55569587Sgreen fatal("input_userauth_failure: no authentication context"); 55669587Sgreen 55769587Sgreen authlist = packet_get_string(NULL); 55869587Sgreen partial = packet_get_char(); 55992559Sdes packet_check_eom(); 56069587Sgreen 561255767Sdes if (partial != 0) { 562323129Sdes verbose("Authenticated with partial success."); 563255767Sdes /* reset state */ 564323134Sdes pubkey_reset(authctxt); 565255767Sdes } 566113911Sdes debug("Authentications that can continue: %s", authlist); 56769587Sgreen 56876262Sgreen userauth(authctxt, authlist); 569294332Sdes return 0; 57076262Sgreen} 571192595Sdes 572192595Sdes/* ARGSUSED */ 573294332Sdesint 57492559Sdesinput_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) 57576262Sgreen{ 57676262Sgreen Authctxt *authctxt = ctxt; 57776262Sgreen Key *key = NULL; 578124211Sdes Identity *id = NULL; 57976262Sgreen Buffer b; 58092559Sdes int pktype, sent = 0; 58192559Sdes u_int alen, blen; 58292559Sdes char *pkalg, *fp; 58392559Sdes u_char *pkblob; 58476262Sgreen 58576262Sgreen if (authctxt == NULL) 58676262Sgreen fatal("input_userauth_pk_ok: no authentication context"); 58776262Sgreen if (datafellows & SSH_BUG_PKOK) { 58876262Sgreen /* this is similar to SSH_BUG_PKAUTH */ 58976262Sgreen debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); 59076262Sgreen pkblob = packet_get_string(&blen); 59176262Sgreen buffer_init(&b); 59276262Sgreen buffer_append(&b, pkblob, blen); 59376262Sgreen pkalg = buffer_get_string(&b, &alen); 59476262Sgreen buffer_free(&b); 59576262Sgreen } else { 59676262Sgreen pkalg = packet_get_string(&alen); 59776262Sgreen pkblob = packet_get_string(&blen); 59876262Sgreen } 59992559Sdes packet_check_eom(); 60076262Sgreen 601124211Sdes debug("Server accepts key: pkalg %s blen %u", pkalg, blen); 60276262Sgreen 603124211Sdes if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { 604124211Sdes debug("unknown pkalg %s", pkalg); 605124211Sdes goto done; 606124211Sdes } 607124211Sdes if ((key = key_from_blob(pkblob, blen)) == NULL) { 608124211Sdes debug("no key from blob. pkalg %s", pkalg); 609124211Sdes goto done; 610124211Sdes } 611124211Sdes if (key->type != pktype) { 612124211Sdes error("input_userauth_pk_ok: type mismatch " 613124211Sdes "for decoded key (received %d, expected %d)", 614124211Sdes key->type, pktype); 615124211Sdes goto done; 616124211Sdes } 617294332Sdes if ((fp = sshkey_fingerprint(key, options.fingerprint_hash, 618294332Sdes SSH_FP_DEFAULT)) == NULL) 619294332Sdes goto done; 620124211Sdes debug2("input_userauth_pk_ok: fp %s", fp); 621255767Sdes free(fp); 622124211Sdes 623126277Sdes /* 624126277Sdes * search keys in the reverse order, because last candidate has been 625126277Sdes * moved to the end of the queue. this also avoids confusion by 626126277Sdes * duplicate keys 627126277Sdes */ 628137019Sdes TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) { 629124211Sdes if (key_equal(key, id->key)) { 630124211Sdes sent = sign_and_send_pubkey(authctxt, id); 63169587Sgreen break; 63269587Sgreen } 633124211Sdes } 634124211Sdesdone: 63576262Sgreen if (key != NULL) 63676262Sgreen key_free(key); 637255767Sdes free(pkalg); 638255767Sdes free(pkblob); 63976262Sgreen 640106130Sdes /* try another method if we did not send a packet */ 64176262Sgreen if (sent == 0) 64276262Sgreen userauth(authctxt, NULL); 643294332Sdes return 0; 644124211Sdes} 64576262Sgreen 646124211Sdes#ifdef GSSAPI 647126277Sdesint 648124211Sdesuserauth_gssapi(Authctxt *authctxt) 649124211Sdes{ 650124211Sdes Gssctxt *gssctxt = NULL; 651126277Sdes static gss_OID_set gss_supported = NULL; 652149753Sdes static u_int mech = 0; 653124211Sdes OM_uint32 min; 654124211Sdes int ok = 0; 655124211Sdes 656124211Sdes /* Try one GSSAPI method at a time, rather than sending them all at 657124211Sdes * once. */ 658124211Sdes 659126277Sdes if (gss_supported == NULL) 660126277Sdes gss_indicate_mechs(&min, &gss_supported); 661124211Sdes 662124211Sdes /* Check to see if the mechanism is usable before we offer it */ 663126277Sdes while (mech < gss_supported->count && !ok) { 664124211Sdes /* My DER encoding requires length<128 */ 665126277Sdes if (gss_supported->elements[mech].length < 128 && 666162856Sdes ssh_gssapi_check_mechanism(&gssctxt, 667162856Sdes &gss_supported->elements[mech], authctxt->host)) { 668124211Sdes ok = 1; /* Mechanism works */ 669124211Sdes } else { 670124211Sdes mech++; 671124211Sdes } 672124211Sdes } 673124211Sdes 674149753Sdes if (!ok) 675149753Sdes return 0; 676124211Sdes 677124211Sdes authctxt->methoddata=(void *)gssctxt; 678124211Sdes 679124211Sdes packet_start(SSH2_MSG_USERAUTH_REQUEST); 680124211Sdes packet_put_cstring(authctxt->server_user); 681124211Sdes packet_put_cstring(authctxt->service); 682124211Sdes packet_put_cstring(authctxt->method->name); 683124211Sdes 684124211Sdes packet_put_int(1); 685124211Sdes 686126277Sdes packet_put_int((gss_supported->elements[mech].length) + 2); 687126277Sdes packet_put_char(SSH_GSS_OIDTYPE); 688126277Sdes packet_put_char(gss_supported->elements[mech].length); 689126277Sdes packet_put_raw(gss_supported->elements[mech].elements, 690126277Sdes gss_supported->elements[mech].length); 691124211Sdes 692124211Sdes packet_send(); 693124211Sdes 694124211Sdes dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); 695124211Sdes dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); 696124211Sdes dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); 697124211Sdes dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); 698124211Sdes 699124211Sdes mech++; /* Move along to next candidate */ 700124211Sdes 701124211Sdes return 1; 70269587Sgreen} 70369587Sgreen 704126277Sdesstatic OM_uint32 705126277Sdesprocess_gssapi_token(void *ctxt, gss_buffer_t recv_tok) 706126277Sdes{ 707126277Sdes Authctxt *authctxt = ctxt; 708126277Sdes Gssctxt *gssctxt = authctxt->methoddata; 709126277Sdes gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; 710149753Sdes gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; 711149753Sdes gss_buffer_desc gssbuf; 712126277Sdes OM_uint32 status, ms, flags; 713126277Sdes Buffer b; 714126277Sdes 715126277Sdes status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, 716126277Sdes recv_tok, &send_tok, &flags); 717126277Sdes 718126277Sdes if (send_tok.length > 0) { 719126277Sdes if (GSS_ERROR(status)) 720126277Sdes packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); 721126277Sdes else 722126277Sdes packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); 723126277Sdes 724126277Sdes packet_put_string(send_tok.value, send_tok.length); 725126277Sdes packet_send(); 726126277Sdes gss_release_buffer(&ms, &send_tok); 727126277Sdes } 728126277Sdes 729126277Sdes if (status == GSS_S_COMPLETE) { 730126277Sdes /* send either complete or MIC, depending on mechanism */ 731126277Sdes if (!(flags & GSS_C_INTEG_FLAG)) { 732126277Sdes packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); 733126277Sdes packet_send(); 734126277Sdes } else { 735126277Sdes ssh_gssapi_buildmic(&b, authctxt->server_user, 736126277Sdes authctxt->service, "gssapi-with-mic"); 737126277Sdes 738126277Sdes gssbuf.value = buffer_ptr(&b); 739126277Sdes gssbuf.length = buffer_len(&b); 740126277Sdes 741126277Sdes status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic); 742126277Sdes 743126277Sdes if (!GSS_ERROR(status)) { 744126277Sdes packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC); 745126277Sdes packet_put_string(mic.value, mic.length); 746126277Sdes 747126277Sdes packet_send(); 748126277Sdes } 749126277Sdes 750126277Sdes buffer_free(&b); 751126277Sdes gss_release_buffer(&ms, &mic); 752126277Sdes } 753126277Sdes } 754126277Sdes 755126277Sdes return status; 756126277Sdes} 757126277Sdes 758192595Sdes/* ARGSUSED */ 759294332Sdesint 760124211Sdesinput_gssapi_response(int type, u_int32_t plen, void *ctxt) 761124211Sdes{ 762124211Sdes Authctxt *authctxt = ctxt; 763124211Sdes Gssctxt *gssctxt; 764124211Sdes int oidlen; 765124211Sdes char *oidv; 766124211Sdes 767124211Sdes if (authctxt == NULL) 768124211Sdes fatal("input_gssapi_response: no authentication context"); 769124211Sdes gssctxt = authctxt->methoddata; 770124211Sdes 771124211Sdes /* Setup our OID */ 772124211Sdes oidv = packet_get_string(&oidlen); 773124211Sdes 774126277Sdes if (oidlen <= 2 || 775126277Sdes oidv[0] != SSH_GSS_OIDTYPE || 776126277Sdes oidv[1] != oidlen - 2) { 777255767Sdes free(oidv); 778126277Sdes debug("Badly encoded mechanism OID received"); 779126277Sdes userauth(authctxt, NULL); 780294332Sdes return 0; 781124211Sdes } 782124211Sdes 783126277Sdes if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) 784126277Sdes fatal("Server returned different OID than expected"); 785126277Sdes 786124211Sdes packet_check_eom(); 787124211Sdes 788255767Sdes free(oidv); 789124211Sdes 790126277Sdes if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) { 791124211Sdes /* Start again with next method on list */ 792124211Sdes debug("Trying to start again"); 793124211Sdes userauth(authctxt, NULL); 794294332Sdes return 0; 795124211Sdes } 796294332Sdes return 0; 797124211Sdes} 798124211Sdes 799192595Sdes/* ARGSUSED */ 800294332Sdesint 801124211Sdesinput_gssapi_token(int type, u_int32_t plen, void *ctxt) 802124211Sdes{ 803124211Sdes Authctxt *authctxt = ctxt; 804124211Sdes gss_buffer_desc recv_tok; 805126277Sdes OM_uint32 status; 806124211Sdes u_int slen; 807124211Sdes 808124211Sdes if (authctxt == NULL) 809124211Sdes fatal("input_gssapi_response: no authentication context"); 810124211Sdes 811124211Sdes recv_tok.value = packet_get_string(&slen); 812124211Sdes recv_tok.length = slen; /* safe typecast */ 813124211Sdes 814124211Sdes packet_check_eom(); 815124211Sdes 816126277Sdes status = process_gssapi_token(ctxt, &recv_tok); 817124211Sdes 818255767Sdes free(recv_tok.value); 819124211Sdes 820124211Sdes if (GSS_ERROR(status)) { 821124211Sdes /* Start again with the next method in the list */ 822124211Sdes userauth(authctxt, NULL); 823294332Sdes return 0; 824124211Sdes } 825294332Sdes return 0; 826124211Sdes} 827124211Sdes 828192595Sdes/* ARGSUSED */ 829294332Sdesint 830124211Sdesinput_gssapi_errtok(int type, u_int32_t plen, void *ctxt) 831124211Sdes{ 832124211Sdes Authctxt *authctxt = ctxt; 833124211Sdes Gssctxt *gssctxt; 834124211Sdes gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; 835124211Sdes gss_buffer_desc recv_tok; 836255767Sdes OM_uint32 ms; 837124211Sdes u_int len; 838124211Sdes 839124211Sdes if (authctxt == NULL) 840124211Sdes fatal("input_gssapi_response: no authentication context"); 841124211Sdes gssctxt = authctxt->methoddata; 842124211Sdes 843124211Sdes recv_tok.value = packet_get_string(&len); 844124211Sdes recv_tok.length = len; 845124211Sdes 846124211Sdes packet_check_eom(); 847124211Sdes 848124211Sdes /* Stick it into GSSAPI and see what it says */ 849255767Sdes (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, 850149753Sdes &recv_tok, &send_tok, NULL); 851124211Sdes 852255767Sdes free(recv_tok.value); 853124211Sdes gss_release_buffer(&ms, &send_tok); 854124211Sdes 855124211Sdes /* Server will be returning a failed packet after this one */ 856294332Sdes return 0; 857124211Sdes} 858124211Sdes 859192595Sdes/* ARGSUSED */ 860294332Sdesint 861124211Sdesinput_gssapi_error(int type, u_int32_t plen, void *ctxt) 862124211Sdes{ 863124211Sdes char *msg; 864124211Sdes char *lang; 865124211Sdes 866255767Sdes /* maj */(void)packet_get_int(); 867255767Sdes /* min */(void)packet_get_int(); 868124211Sdes msg=packet_get_string(NULL); 869124211Sdes lang=packet_get_string(NULL); 870124211Sdes 871124211Sdes packet_check_eom(); 872124211Sdes 873157019Sdes debug("Server GSSAPI Error:\n%s", msg); 874255767Sdes free(msg); 875255767Sdes free(lang); 876294332Sdes return 0; 877124211Sdes} 878124211Sdes#endif /* GSSAPI */ 879124211Sdes 88060573Skrisint 88169587Sgreenuserauth_none(Authctxt *authctxt) 88260573Skris{ 88369587Sgreen /* initial userauth request */ 88469587Sgreen packet_start(SSH2_MSG_USERAUTH_REQUEST); 88569587Sgreen packet_put_cstring(authctxt->server_user); 88669587Sgreen packet_put_cstring(authctxt->service); 88769587Sgreen packet_put_cstring(authctxt->method->name); 88869587Sgreen packet_send(); 88969587Sgreen return 1; 89069587Sgreen} 89169587Sgreen 89269587Sgreenint 89369587Sgreenuserauth_passwd(Authctxt *authctxt) 89469587Sgreen{ 89560573Skris static int attempt = 0; 89698684Sdes char prompt[150]; 89760573Skris char *password; 898204917Sdes const char *host = options.host_key_alias ? options.host_key_alias : 899204917Sdes authctxt->host; 90060573Skris 90165668Skris if (attempt++ >= options.number_of_password_prompts) 90260573Skris return 0; 90360573Skris 90492559Sdes if (attempt != 1) 90565668Skris error("Permission denied, please try again."); 90665668Skris 90776262Sgreen snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", 908204917Sdes authctxt->server_user, host); 90960573Skris password = read_passphrase(prompt, 0); 91060573Skris packet_start(SSH2_MSG_USERAUTH_REQUEST); 91169587Sgreen packet_put_cstring(authctxt->server_user); 91269587Sgreen packet_put_cstring(authctxt->service); 91369587Sgreen packet_put_cstring(authctxt->method->name); 91460573Skris packet_put_char(0); 91593704Sdes packet_put_cstring(password); 916263712Sdes explicit_bzero(password, strlen(password)); 917255767Sdes free(password); 91892559Sdes packet_add_padding(64); 91960573Skris packet_send(); 92098684Sdes 92198684Sdes dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, 92298684Sdes &input_userauth_passwd_changereq); 92398684Sdes 92460573Skris return 1; 92560573Skris} 926192595Sdes 92798684Sdes/* 92898684Sdes * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST 92998684Sdes */ 930192595Sdes/* ARGSUSED */ 931294332Sdesint 93298941Sdesinput_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) 93398684Sdes{ 93498684Sdes Authctxt *authctxt = ctxt; 93598684Sdes char *info, *lang, *password = NULL, *retype = NULL; 93698684Sdes char prompt[150]; 937323136Sdes const char *host; 93860573Skris 93998684Sdes debug2("input_userauth_passwd_changereq"); 94098684Sdes 94198684Sdes if (authctxt == NULL) 94298684Sdes fatal("input_userauth_passwd_changereq: " 94398684Sdes "no authentication context"); 944323136Sdes host = options.host_key_alias ? options.host_key_alias : authctxt->host; 94598684Sdes 94698684Sdes info = packet_get_string(NULL); 94798684Sdes lang = packet_get_string(NULL); 94898684Sdes if (strlen(info) > 0) 949124211Sdes logit("%s", info); 950255767Sdes free(info); 951255767Sdes free(lang); 95298684Sdes packet_start(SSH2_MSG_USERAUTH_REQUEST); 95398684Sdes packet_put_cstring(authctxt->server_user); 95498684Sdes packet_put_cstring(authctxt->service); 95598684Sdes packet_put_cstring(authctxt->method->name); 95698684Sdes packet_put_char(1); /* additional info */ 95798684Sdes snprintf(prompt, sizeof(prompt), 95898684Sdes "Enter %.30s@%.128s's old password: ", 959204917Sdes authctxt->server_user, host); 96098684Sdes password = read_passphrase(prompt, 0); 96198684Sdes packet_put_cstring(password); 962263712Sdes explicit_bzero(password, strlen(password)); 963255767Sdes free(password); 96498684Sdes password = NULL; 96598684Sdes while (password == NULL) { 96698684Sdes snprintf(prompt, sizeof(prompt), 96798684Sdes "Enter %.30s@%.128s's new password: ", 968204917Sdes authctxt->server_user, host); 96998684Sdes password = read_passphrase(prompt, RP_ALLOW_EOF); 97098684Sdes if (password == NULL) { 97198684Sdes /* bail out */ 972294332Sdes return 0; 97398684Sdes } 97498684Sdes snprintf(prompt, sizeof(prompt), 97598684Sdes "Retype %.30s@%.128s's new password: ", 976204917Sdes authctxt->server_user, host); 97798684Sdes retype = read_passphrase(prompt, 0); 97898684Sdes if (strcmp(password, retype) != 0) { 979263712Sdes explicit_bzero(password, strlen(password)); 980255767Sdes free(password); 981124211Sdes logit("Mismatch; try again, EOF to quit."); 98298684Sdes password = NULL; 98398684Sdes } 984263712Sdes explicit_bzero(retype, strlen(retype)); 985255767Sdes free(retype); 98698684Sdes } 98798684Sdes packet_put_cstring(password); 988263712Sdes explicit_bzero(password, strlen(password)); 989255767Sdes free(password); 99098684Sdes packet_add_padding(64); 99198684Sdes packet_send(); 99298684Sdes 99398684Sdes dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, 99498684Sdes &input_userauth_passwd_changereq); 995294332Sdes return 0; 99698684Sdes} 99798684Sdes 998296633Sdesstatic const char * 999323136Sdeskey_sign_encode(const struct sshkey *key) 1000296633Sdes{ 1001296633Sdes struct ssh *ssh = active_state; 1002296633Sdes 1003323136Sdes if (key->type == KEY_RSA) { 1004296633Sdes switch (ssh->kex->rsa_sha2) { 1005296633Sdes case 256: 1006296633Sdes return "rsa-sha2-256"; 1007296633Sdes case 512: 1008296633Sdes return "rsa-sha2-512"; 1009296633Sdes } 1010296633Sdes } 1011323136Sdes return key_ssh_name(key); 1012296633Sdes} 1013296633Sdes 1014124211Sdesstatic int 1015294332Sdesidentity_sign(struct identity *id, u_char **sigp, size_t *lenp, 1016294332Sdes const u_char *data, size_t datalen, u_int compat) 101776262Sgreen{ 1018124211Sdes Key *prv; 1019124211Sdes int ret; 102098684Sdes 1021124211Sdes /* the agent supports this key */ 1022323136Sdes if (id->key != NULL && id->agent_fd != -1) 1023294332Sdes return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp, 1024323136Sdes data, datalen, key_sign_encode(id->key), compat); 1025294332Sdes 1026124211Sdes /* 1027124211Sdes * we have already loaded the private key or 1028124211Sdes * the private key is stored in external hardware 1029124211Sdes */ 1030323136Sdes if (id->key != NULL && 1031323136Sdes (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) 1032323136Sdes return (sshkey_sign(id->key, sigp, lenp, data, datalen, 1033323136Sdes key_sign_encode(id->key), compat)); 1034323136Sdes 1035124211Sdes /* load the private key from the file */ 1036296633Sdes if ((prv = load_identity_file(id)) == NULL) 1037296633Sdes return SSH_ERR_KEY_NOT_FOUND; 1038323136Sdes ret = sshkey_sign(prv, sigp, lenp, data, datalen, 1039323136Sdes key_sign_encode(prv), compat); 1040294332Sdes sshkey_free(prv); 1041124211Sdes return (ret); 104276262Sgreen} 104376262Sgreen 104492559Sdesstatic int 1045323136Sdesid_filename_matches(Identity *id, Identity *private_id) 1046323136Sdes{ 1047323136Sdes const char *suffixes[] = { ".pub", "-cert.pub", NULL }; 1048323136Sdes size_t len = strlen(id->filename), plen = strlen(private_id->filename); 1049323136Sdes size_t i, slen; 1050323136Sdes 1051323136Sdes if (strcmp(id->filename, private_id->filename) == 0) 1052323136Sdes return 1; 1053323136Sdes for (i = 0; suffixes[i]; i++) { 1054323136Sdes slen = strlen(suffixes[i]); 1055323136Sdes if (len > slen && plen == len - slen && 1056323136Sdes strcmp(id->filename + (len - slen), suffixes[i]) == 0 && 1057323136Sdes memcmp(id->filename, private_id->filename, plen) == 0) 1058323136Sdes return 1; 1059323136Sdes } 1060323136Sdes return 0; 1061323136Sdes} 1062323136Sdes 1063323136Sdesstatic int 1064124211Sdessign_and_send_pubkey(Authctxt *authctxt, Identity *id) 106560573Skris{ 106660573Skris Buffer b; 1067296633Sdes Identity *private_id; 106876262Sgreen u_char *blob, *signature; 1069294332Sdes size_t slen; 1070296633Sdes u_int bloblen, skip = 0; 1071296633Sdes int matched, ret = -1, have_sig = 1; 1072215116Sdes char *fp; 107360573Skris 1074294332Sdes if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash, 1075294332Sdes SSH_FP_DEFAULT)) == NULL) 1076294332Sdes return 0; 1077296633Sdes debug3("%s: %s %s", __func__, key_type(id->key), fp); 1078255767Sdes free(fp); 107960573Skris 1080124211Sdes if (key_to_blob(id->key, &blob, &bloblen) == 0) { 108176262Sgreen /* we cannot handle this key */ 108276262Sgreen debug3("sign_and_send_pubkey: cannot handle key"); 108376262Sgreen return 0; 108476262Sgreen } 108560573Skris /* data to be signed */ 108660573Skris buffer_init(&b); 108769587Sgreen if (datafellows & SSH_OLD_SESSIONID) { 108869587Sgreen buffer_append(&b, session_id2, session_id2_len); 108976262Sgreen skip = session_id2_len; 109069587Sgreen } else { 109165668Skris buffer_put_string(&b, session_id2, session_id2_len); 109265668Skris skip = buffer_len(&b); 109365668Skris } 109460573Skris buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); 109569587Sgreen buffer_put_cstring(&b, authctxt->server_user); 109660573Skris buffer_put_cstring(&b, 109776262Sgreen datafellows & SSH_BUG_PKSERVICE ? 109860573Skris "ssh-userauth" : 109969587Sgreen authctxt->service); 110076262Sgreen if (datafellows & SSH_BUG_PKAUTH) { 110176262Sgreen buffer_put_char(&b, have_sig); 110276262Sgreen } else { 110376262Sgreen buffer_put_cstring(&b, authctxt->method->name); 110476262Sgreen buffer_put_char(&b, have_sig); 1105323136Sdes buffer_put_cstring(&b, key_sign_encode(id->key)); 110676262Sgreen } 110760573Skris buffer_put_string(&b, blob, bloblen); 110860573Skris 1109296633Sdes /* 1110296633Sdes * If the key is an certificate, try to find a matching private key 1111296633Sdes * and use it to complete the signature. 1112323129Sdes * If no such private key exists, fall back to trying the certificate 1113323129Sdes * key itself in case it has a private half already loaded. 1114296633Sdes */ 1115296633Sdes if (key_is_cert(id->key)) { 1116296633Sdes matched = 0; 1117296633Sdes TAILQ_FOREACH(private_id, &authctxt->keys, next) { 1118296633Sdes if (sshkey_equal_public(id->key, private_id->key) && 1119296633Sdes id->key->type != private_id->key->type) { 1120296633Sdes id = private_id; 1121296633Sdes matched = 1; 1122296633Sdes break; 1123296633Sdes } 1124296633Sdes } 1125323136Sdes /* 1126323136Sdes * Exact key matches are preferred, but also allow 1127323136Sdes * filename matches for non-PKCS#11/agent keys that 1128323136Sdes * didn't load public keys. This supports the case 1129323136Sdes * of keeping just a private key file and public 1130323136Sdes * certificate on disk. 1131323136Sdes */ 1132323136Sdes if (!matched && !id->isprivate && id->agent_fd == -1 && 1133323136Sdes (id->key->flags & SSHKEY_FLAG_EXT) == 0) { 1134323136Sdes TAILQ_FOREACH(private_id, &authctxt->keys, next) { 1135323136Sdes if (private_id->key == NULL && 1136323136Sdes id_filename_matches(id, private_id)) { 1137323136Sdes id = private_id; 1138323136Sdes matched = 1; 1139323136Sdes break; 1140323136Sdes } 1141323136Sdes } 1142323136Sdes } 1143296633Sdes if (matched) { 1144296633Sdes debug2("%s: using private key \"%s\"%s for " 1145296633Sdes "certificate", __func__, id->filename, 1146296633Sdes id->agent_fd != -1 ? " from agent" : ""); 1147296633Sdes } else { 1148323129Sdes debug("%s: no separate private key for certificate " 1149296633Sdes "\"%s\"", __func__, id->filename); 1150296633Sdes } 1151296633Sdes } 1152296633Sdes 115360573Skris /* generate signature */ 1154124211Sdes ret = identity_sign(id, &signature, &slen, 1155294332Sdes buffer_ptr(&b), buffer_len(&b), datafellows); 1156294332Sdes if (ret != 0) { 1157296633Sdes if (ret != SSH_ERR_KEY_NOT_FOUND) 1158296633Sdes error("%s: signing failed: %s", __func__, ssh_err(ret)); 1159255767Sdes free(blob); 116065668Skris buffer_free(&b); 116165668Skris return 0; 116265668Skris } 116376262Sgreen#ifdef DEBUG_PK 116460573Skris buffer_dump(&b); 116560573Skris#endif 116676262Sgreen if (datafellows & SSH_BUG_PKSERVICE) { 116760573Skris buffer_clear(&b); 116860573Skris buffer_append(&b, session_id2, session_id2_len); 116976262Sgreen skip = session_id2_len; 117060573Skris buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); 117169587Sgreen buffer_put_cstring(&b, authctxt->server_user); 117269587Sgreen buffer_put_cstring(&b, authctxt->service); 117369587Sgreen buffer_put_cstring(&b, authctxt->method->name); 117469587Sgreen buffer_put_char(&b, have_sig); 117576262Sgreen if (!(datafellows & SSH_BUG_PKAUTH)) 1176124211Sdes buffer_put_cstring(&b, key_ssh_name(id->key)); 117760573Skris buffer_put_string(&b, blob, bloblen); 117860573Skris } 1179255767Sdes free(blob); 118076262Sgreen 118160573Skris /* append signature */ 118260573Skris buffer_put_string(&b, signature, slen); 1183255767Sdes free(signature); 118460573Skris 118560573Skris /* skip session id and packet type */ 118665668Skris if (buffer_len(&b) < skip + 1) 118769587Sgreen fatal("userauth_pubkey: internal error"); 118865668Skris buffer_consume(&b, skip + 1); 118960573Skris 119060573Skris /* put remaining data from buffer into packet */ 119160573Skris packet_start(SSH2_MSG_USERAUTH_REQUEST); 119260573Skris packet_put_raw(buffer_ptr(&b), buffer_len(&b)); 119360573Skris buffer_free(&b); 119460573Skris packet_send(); 119565668Skris 119660573Skris return 1; 119760573Skris} 119860573Skris 119992559Sdesstatic int 1200124211Sdessend_pubkey_test(Authctxt *authctxt, Identity *id) 120169587Sgreen{ 120276262Sgreen u_char *blob; 120392559Sdes u_int bloblen, have_sig = 0; 120476262Sgreen 120576262Sgreen debug3("send_pubkey_test"); 120676262Sgreen 1207124211Sdes if (key_to_blob(id->key, &blob, &bloblen) == 0) { 120876262Sgreen /* we cannot handle this key */ 120976262Sgreen debug3("send_pubkey_test: cannot handle key"); 121076262Sgreen return 0; 121176262Sgreen } 121276262Sgreen /* register callback for USERAUTH_PK_OK message */ 121376262Sgreen dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); 121476262Sgreen 121576262Sgreen packet_start(SSH2_MSG_USERAUTH_REQUEST); 121676262Sgreen packet_put_cstring(authctxt->server_user); 121776262Sgreen packet_put_cstring(authctxt->service); 121876262Sgreen packet_put_cstring(authctxt->method->name); 121976262Sgreen packet_put_char(have_sig); 122076262Sgreen if (!(datafellows & SSH_BUG_PKAUTH)) 1221323136Sdes packet_put_cstring(key_sign_encode(id->key)); 122276262Sgreen packet_put_string(blob, bloblen); 1223255767Sdes free(blob); 122476262Sgreen packet_send(); 122576262Sgreen return 1; 122669587Sgreen} 122769587Sgreen 122892559Sdesstatic Key * 1229296633Sdesload_identity_file(Identity *id) 123065668Skris{ 1231296633Sdes Key *private = NULL; 1232296633Sdes char prompt[300], *passphrase, *comment; 1233294332Sdes int r, perm_ok = 0, quit = 0, i; 123465668Skris struct stat st; 123565668Skris 1236296633Sdes if (stat(id->filename, &st) < 0) { 1237296633Sdes (id->userprovided ? logit : debug3)("no such identity: %s: %s", 1238296633Sdes id->filename, strerror(errno)); 123976262Sgreen return NULL; 124065668Skris } 1241294332Sdes snprintf(prompt, sizeof prompt, 1242296633Sdes "Enter passphrase for key '%.100s': ", id->filename); 1243294332Sdes for (i = 0; i <= options.number_of_password_prompts; i++) { 1244294332Sdes if (i == 0) 1245294332Sdes passphrase = ""; 1246294332Sdes else { 124769587Sgreen passphrase = read_passphrase(prompt, 0); 1248294332Sdes if (*passphrase == '\0') { 124969587Sgreen debug2("no passphrase given, try next key"); 1250294332Sdes free(passphrase); 1251294332Sdes break; 1252294332Sdes } 1253294332Sdes } 1254296633Sdes switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename, 1255296633Sdes passphrase, &private, &comment, &perm_ok))) { 1256294332Sdes case 0: 1257294332Sdes break; 1258294332Sdes case SSH_ERR_KEY_WRONG_PASSPHRASE: 1259294332Sdes if (options.batch_mode) { 126076262Sgreen quit = 1; 1261294332Sdes break; 126269587Sgreen } 1263294332Sdes if (i != 0) 1264294332Sdes debug2("bad passphrase given, try again..."); 1265294332Sdes break; 1266294332Sdes case SSH_ERR_SYSTEM_ERROR: 1267294332Sdes if (errno == ENOENT) { 1268294332Sdes debug2("Load key \"%s\": %s", 1269296633Sdes id->filename, ssh_err(r)); 1270294332Sdes quit = 1; 1271294332Sdes break; 1272294332Sdes } 1273294332Sdes /* FALLTHROUGH */ 1274294332Sdes default: 1275296633Sdes error("Load key \"%s\": %s", id->filename, ssh_err(r)); 1276294332Sdes quit = 1; 1277294332Sdes break; 1278294332Sdes } 1279296633Sdes if (!quit && private != NULL && id->agent_fd == -1 && 1280296633Sdes !(id->key && id->isprivate)) 1281296633Sdes maybe_add_key_to_agent(id->filename, private, comment, 1282296633Sdes passphrase); 1283294332Sdes if (i > 0) { 1284263712Sdes explicit_bzero(passphrase, strlen(passphrase)); 1285255767Sdes free(passphrase); 128669587Sgreen } 1287296633Sdes free(comment); 1288294332Sdes if (private != NULL || quit) 1289294332Sdes break; 129065668Skris } 129176262Sgreen return private; 129276262Sgreen} 129376262Sgreen 1294124211Sdes/* 1295124211Sdes * try keys in the following order: 1296296633Sdes * 1. certificates listed in the config file 1297296633Sdes * 2. other input certificates 1298296633Sdes * 3. agent keys that are found in the config file 1299296633Sdes * 4. other agent keys 1300296633Sdes * 5. keys that are only listed in the config file 1301124211Sdes */ 1302124211Sdesstatic void 1303124211Sdespubkey_prepare(Authctxt *authctxt) 130476262Sgreen{ 1305294332Sdes struct identity *id, *id2, *tmp; 1306294332Sdes struct idlist agent, files, *preferred; 1307294332Sdes struct sshkey *key; 1308296633Sdes int agent_fd = -1, i, r, found; 1309294332Sdes size_t j; 1310294332Sdes struct ssh_identitylist *idlist; 131176262Sgreen 1312124211Sdes TAILQ_INIT(&agent); /* keys from the agent */ 1313124211Sdes TAILQ_INIT(&files); /* keys from the config file */ 1314124211Sdes preferred = &authctxt->keys; 1315124211Sdes TAILQ_INIT(preferred); /* preferred order of keys */ 131692559Sdes 1317248619Sdes /* list of keys stored in the filesystem and PKCS#11 */ 1318124211Sdes for (i = 0; i < options.num_identity_files; i++) { 1319124211Sdes key = options.identity_keys[i]; 1320124211Sdes if (key && key->type == KEY_RSA1) 1321124211Sdes continue; 1322204917Sdes if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER) 1323204917Sdes continue; 1324124211Sdes options.identity_keys[i] = NULL; 1325162856Sdes id = xcalloc(1, sizeof(*id)); 1326296633Sdes id->agent_fd = -1; 1327124211Sdes id->key = key; 1328124211Sdes id->filename = xstrdup(options.identity_files[i]); 1329249016Sdes id->userprovided = options.identity_file_userprovided[i]; 1330124211Sdes TAILQ_INSERT_TAIL(&files, id, next); 1331124211Sdes } 1332296633Sdes /* list of certificates specified by user */ 1333296633Sdes for (i = 0; i < options.num_certificate_files; i++) { 1334296633Sdes key = options.certificates[i]; 1335296633Sdes if (!key_is_cert(key) || key->cert == NULL || 1336296633Sdes key->cert->type != SSH2_CERT_TYPE_USER) 1337296633Sdes continue; 1338296633Sdes id = xcalloc(1, sizeof(*id)); 1339296633Sdes id->agent_fd = -1; 1340296633Sdes id->key = key; 1341296633Sdes id->filename = xstrdup(options.certificate_files[i]); 1342296633Sdes id->userprovided = options.certificate_file_userprovided[i]; 1343296633Sdes TAILQ_INSERT_TAIL(preferred, id, next); 1344296633Sdes } 1345124211Sdes /* list of keys supported by the agent */ 1346294332Sdes if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) { 1347294332Sdes if (r != SSH_ERR_AGENT_NOT_PRESENT) 1348294332Sdes debug("%s: ssh_get_authentication_socket: %s", 1349294332Sdes __func__, ssh_err(r)); 1350294332Sdes } else if ((r = ssh_fetch_identitylist(agent_fd, 2, &idlist)) != 0) { 1351294332Sdes if (r != SSH_ERR_AGENT_NO_IDENTITIES) 1352294332Sdes debug("%s: ssh_fetch_identitylist: %s", 1353294332Sdes __func__, ssh_err(r)); 1354296633Sdes close(agent_fd); 1355294332Sdes } else { 1356294332Sdes for (j = 0; j < idlist->nkeys; j++) { 1357124211Sdes found = 0; 1358124211Sdes TAILQ_FOREACH(id, &files, next) { 1359294332Sdes /* 1360294332Sdes * agent keys from the config file are 1361294332Sdes * preferred 1362294332Sdes */ 1363294332Sdes if (sshkey_equal(idlist->keys[j], id->key)) { 1364124211Sdes TAILQ_REMOVE(&files, id, next); 1365124211Sdes TAILQ_INSERT_TAIL(preferred, id, next); 1366294332Sdes id->agent_fd = agent_fd; 1367124211Sdes found = 1; 1368124211Sdes break; 1369124211Sdes } 1370124211Sdes } 1371128460Sdes if (!found && !options.identities_only) { 1372162856Sdes id = xcalloc(1, sizeof(*id)); 1373294332Sdes /* XXX "steals" key/comment from idlist */ 1374294332Sdes id->key = idlist->keys[j]; 1375294332Sdes id->filename = idlist->comments[j]; 1376294332Sdes idlist->keys[j] = NULL; 1377294332Sdes idlist->comments[j] = NULL; 1378294332Sdes id->agent_fd = agent_fd; 1379124211Sdes TAILQ_INSERT_TAIL(&agent, id, next); 1380124211Sdes } 1381124211Sdes } 1382294332Sdes ssh_free_identitylist(idlist); 1383124211Sdes /* append remaining agent keys */ 1384124211Sdes for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { 1385124211Sdes TAILQ_REMOVE(&agent, id, next); 1386124211Sdes TAILQ_INSERT_TAIL(preferred, id, next); 1387124211Sdes } 1388294332Sdes authctxt->agent_fd = agent_fd; 1389124211Sdes } 1390323129Sdes /* Prefer PKCS11 keys that are explicitly listed */ 1391323129Sdes TAILQ_FOREACH_SAFE(id, &files, next, tmp) { 1392323129Sdes if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0) 1393323129Sdes continue; 1394323129Sdes found = 0; 1395323129Sdes TAILQ_FOREACH(id2, &files, next) { 1396323129Sdes if (id2->key == NULL || 1397323129Sdes (id2->key->flags & SSHKEY_FLAG_EXT) == 0) 1398323129Sdes continue; 1399323129Sdes if (sshkey_equal(id->key, id2->key)) { 1400323129Sdes TAILQ_REMOVE(&files, id, next); 1401323129Sdes TAILQ_INSERT_TAIL(preferred, id, next); 1402323129Sdes found = 1; 1403323129Sdes break; 1404323129Sdes } 1405323129Sdes } 1406323129Sdes /* If IdentitiesOnly set and key not found then don't use it */ 1407323129Sdes if (!found && options.identities_only) { 1408323129Sdes TAILQ_REMOVE(&files, id, next); 1409323129Sdes explicit_bzero(id, sizeof(*id)); 1410323129Sdes free(id); 1411323129Sdes } 1412323129Sdes } 1413124211Sdes /* append remaining keys from the config file */ 1414124211Sdes for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { 1415124211Sdes TAILQ_REMOVE(&files, id, next); 1416124211Sdes TAILQ_INSERT_TAIL(preferred, id, next); 1417124211Sdes } 1418296633Sdes /* finally, filter by PubkeyAcceptedKeyTypes */ 1419296633Sdes TAILQ_FOREACH_SAFE(id, preferred, next, id2) { 1420296633Sdes if (id->key != NULL && 1421296633Sdes match_pattern_list(sshkey_ssh_name(id->key), 1422296633Sdes options.pubkey_key_types, 0) != 1) { 1423296633Sdes debug("Skipping %s key %s - " 1424296633Sdes "not in PubkeyAcceptedKeyTypes", 1425296633Sdes sshkey_ssh_name(id->key), id->filename); 1426296633Sdes TAILQ_REMOVE(preferred, id, next); 1427296633Sdes sshkey_free(id->key); 1428296633Sdes free(id->filename); 1429296633Sdes memset(id, 0, sizeof(*id)); 1430296633Sdes continue; 1431296633Sdes } 1432296633Sdes debug2("key: %s (%p)%s%s", id->filename, id->key, 1433296633Sdes id->userprovided ? ", explicit" : "", 1434296633Sdes id->agent_fd != -1 ? ", agent" : ""); 1435124211Sdes } 143665668Skris} 143765668Skris 1438124211Sdesstatic void 1439124211Sdespubkey_cleanup(Authctxt *authctxt) 144065668Skris{ 1441124211Sdes Identity *id; 144265668Skris 1443294332Sdes if (authctxt->agent_fd != -1) 1444294332Sdes ssh_close_authentication_socket(authctxt->agent_fd); 1445124211Sdes for (id = TAILQ_FIRST(&authctxt->keys); id; 1446124211Sdes id = TAILQ_FIRST(&authctxt->keys)) { 1447124211Sdes TAILQ_REMOVE(&authctxt->keys, id, next); 1448296633Sdes sshkey_free(id->key); 1449255767Sdes free(id->filename); 1450255767Sdes free(id); 145165668Skris } 145265668Skris} 145365668Skris 1454323134Sdesstatic void 1455323134Sdespubkey_reset(Authctxt *authctxt) 1456323134Sdes{ 1457323134Sdes Identity *id; 1458323134Sdes 1459323134Sdes TAILQ_FOREACH(id, &authctxt->keys, next) 1460323134Sdes id->tried = 0; 1461323134Sdes} 1462323134Sdes 1463294464Sdesstatic int 1464294464Sdestry_identity(Identity *id) 1465294464Sdes{ 1466294464Sdes if (!id->key) 1467294464Sdes return (0); 1468294464Sdes if (key_type_plain(id->key->type) == KEY_RSA && 1469294464Sdes (datafellows & SSH_BUG_RSASIGMD5) != 0) { 1470294464Sdes debug("Skipped %s key %s for RSA/MD5 server", 1471294464Sdes key_type(id->key), id->filename); 1472294464Sdes return (0); 1473294464Sdes } 1474294464Sdes return (id->key->type != KEY_RSA1); 1475294464Sdes} 1476294464Sdes 147769587Sgreenint 147869587Sgreenuserauth_pubkey(Authctxt *authctxt) 147969587Sgreen{ 1480124211Sdes Identity *id; 148169587Sgreen int sent = 0; 148269587Sgreen 1483124211Sdes while ((id = TAILQ_FIRST(&authctxt->keys))) { 1484124211Sdes if (id->tried++) 1485124211Sdes return (0); 1486126277Sdes /* move key to the end of the queue */ 1487124211Sdes TAILQ_REMOVE(&authctxt->keys, id, next); 1488124211Sdes TAILQ_INSERT_TAIL(&authctxt->keys, id, next); 1489124211Sdes /* 1490124211Sdes * send a test message if we have the public key. for 1491124211Sdes * encrypted keys we cannot do this and have to load the 1492124211Sdes * private key instead 1493124211Sdes */ 1494261320Sdes if (id->key != NULL) { 1495294464Sdes if (try_identity(id)) { 1496261320Sdes debug("Offering %s public key: %s", 1497261320Sdes key_type(id->key), id->filename); 1498261320Sdes sent = send_pubkey_test(authctxt, id); 1499261320Sdes } 1500261320Sdes } else { 1501124211Sdes debug("Trying private key: %s", id->filename); 1502296633Sdes id->key = load_identity_file(id); 1503124211Sdes if (id->key != NULL) { 1504294464Sdes if (try_identity(id)) { 1505294464Sdes id->isprivate = 1; 1506261320Sdes sent = sign_and_send_pubkey( 1507261320Sdes authctxt, id); 1508261320Sdes } 1509124211Sdes key_free(id->key); 1510124211Sdes id->key = NULL; 1511323134Sdes id->isprivate = 0; 151276262Sgreen } 151376262Sgreen } 1514124211Sdes if (sent) 1515124211Sdes return (sent); 151676262Sgreen } 1517124211Sdes return (0); 151869587Sgreen} 151969587Sgreen 152069587Sgreen/* 152169587Sgreen * Send userauth request message specifying keyboard-interactive method. 152269587Sgreen */ 152369587Sgreenint 152469587Sgreenuserauth_kbdint(Authctxt *authctxt) 152569587Sgreen{ 152669587Sgreen static int attempt = 0; 152769587Sgreen 152869587Sgreen if (attempt++ >= options.number_of_password_prompts) 152969587Sgreen return 0; 153092559Sdes /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ 153192559Sdes if (attempt > 1 && !authctxt->info_req_seen) { 153292559Sdes debug3("userauth_kbdint: disable: no info_req_seen"); 153392559Sdes dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); 153492559Sdes return 0; 153592559Sdes } 153669587Sgreen 153769587Sgreen debug2("userauth_kbdint"); 153869587Sgreen packet_start(SSH2_MSG_USERAUTH_REQUEST); 153969587Sgreen packet_put_cstring(authctxt->server_user); 154069587Sgreen packet_put_cstring(authctxt->service); 154169587Sgreen packet_put_cstring(authctxt->method->name); 154269587Sgreen packet_put_cstring(""); /* lang */ 154369587Sgreen packet_put_cstring(options.kbd_interactive_devices ? 154469587Sgreen options.kbd_interactive_devices : ""); 154569587Sgreen packet_send(); 154669587Sgreen 154769587Sgreen dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); 154869587Sgreen return 1; 154969587Sgreen} 155069587Sgreen 155169587Sgreen/* 155276262Sgreen * parse INFO_REQUEST, prompt user and send INFO_RESPONSE 155369587Sgreen */ 1554294332Sdesint 155592559Sdesinput_userauth_info_req(int type, u_int32_t seq, void *ctxt) 155660573Skris{ 155769587Sgreen Authctxt *authctxt = ctxt; 155876262Sgreen char *name, *inst, *lang, *prompt, *response; 155976262Sgreen u_int num_prompts, i; 156069587Sgreen int echo = 0; 156160573Skris 156269587Sgreen debug2("input_userauth_info_req"); 156369587Sgreen 156469587Sgreen if (authctxt == NULL) 156569587Sgreen fatal("input_userauth_info_req: no authentication context"); 156669587Sgreen 156792559Sdes authctxt->info_req_seen = 1; 156892559Sdes 156969587Sgreen name = packet_get_string(NULL); 157069587Sgreen inst = packet_get_string(NULL); 157169587Sgreen lang = packet_get_string(NULL); 157269587Sgreen if (strlen(name) > 0) 1573124211Sdes logit("%s", name); 157469587Sgreen if (strlen(inst) > 0) 1575124211Sdes logit("%s", inst); 1576255767Sdes free(name); 1577255767Sdes free(inst); 1578255767Sdes free(lang); 157969587Sgreen 158069587Sgreen num_prompts = packet_get_int(); 158169587Sgreen /* 158269587Sgreen * Begin to build info response packet based on prompts requested. 158369587Sgreen * We commit to providing the correct number of responses, so if 158469587Sgreen * further on we run into a problem that prevents this, we have to 158569587Sgreen * be sure and clean this up and send a correct error response. 158669587Sgreen */ 158769587Sgreen packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); 158869587Sgreen packet_put_int(num_prompts); 158969587Sgreen 159092559Sdes debug2("input_userauth_info_req: num_prompts %d", num_prompts); 159169587Sgreen for (i = 0; i < num_prompts; i++) { 159269587Sgreen prompt = packet_get_string(NULL); 159369587Sgreen echo = packet_get_char(); 159469587Sgreen 159592559Sdes response = read_passphrase(prompt, echo ? RP_ECHO : 0); 159669587Sgreen 159793704Sdes packet_put_cstring(response); 1598263712Sdes explicit_bzero(response, strlen(response)); 1599255767Sdes free(response); 1600255767Sdes free(prompt); 160169587Sgreen } 160292559Sdes packet_check_eom(); /* done with parsing incoming message. */ 160369587Sgreen 160492559Sdes packet_add_padding(64); 160560573Skris packet_send(); 1606294332Sdes return 0; 160769587Sgreen} 160860573Skris 160998684Sdesstatic int 1610294332Sdesssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp, 1611294332Sdes const u_char *data, size_t datalen) 161298684Sdes{ 1613294332Sdes struct sshbuf *b; 161498684Sdes struct stat st; 161598684Sdes pid_t pid; 1616294332Sdes int i, r, to[2], from[2], status, sock = packet_get_connection_in(); 1617294332Sdes u_char rversion = 0, version = 2; 1618294332Sdes void (*osigchld)(int); 161998684Sdes 1620294332Sdes *sigp = NULL; 1621294332Sdes *lenp = 0; 162298684Sdes 162398684Sdes if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { 1624294332Sdes error("%s: not installed: %s", __func__, strerror(errno)); 162598684Sdes return -1; 162698684Sdes } 1627294332Sdes if (fflush(stdout) != 0) { 1628294332Sdes error("%s: fflush: %s", __func__, strerror(errno)); 1629294332Sdes return -1; 1630294332Sdes } 163198684Sdes if (pipe(to) < 0) { 1632294332Sdes error("%s: pipe: %s", __func__, strerror(errno)); 163398684Sdes return -1; 163498684Sdes } 163598684Sdes if (pipe(from) < 0) { 1636294332Sdes error("%s: pipe: %s", __func__, strerror(errno)); 163798684Sdes return -1; 163898684Sdes } 163998684Sdes if ((pid = fork()) < 0) { 1640294332Sdes error("%s: fork: %s", __func__, strerror(errno)); 164198684Sdes return -1; 164298684Sdes } 1643294332Sdes osigchld = signal(SIGCHLD, SIG_DFL); 164498684Sdes if (pid == 0) { 1645204917Sdes /* keep the socket on exec */ 1646294332Sdes fcntl(sock, F_SETFD, 0); 1647162856Sdes permanently_drop_suid(getuid()); 164898684Sdes close(from[0]); 164998684Sdes if (dup2(from[1], STDOUT_FILENO) < 0) 1650294332Sdes fatal("%s: dup2: %s", __func__, strerror(errno)); 165198684Sdes close(to[1]); 165298684Sdes if (dup2(to[0], STDIN_FILENO) < 0) 1653294332Sdes fatal("%s: dup2: %s", __func__, strerror(errno)); 165498684Sdes close(from[1]); 165598684Sdes close(to[0]); 1656294332Sdes /* Close everything but stdio and the socket */ 1657294332Sdes for (i = STDERR_FILENO + 1; i < sock; i++) 1658294332Sdes close(i); 1659294332Sdes closefrom(sock + 1); 1660294332Sdes debug3("%s: [child] pid=%ld, exec %s", 1661294332Sdes __func__, (long)getpid(), _PATH_SSH_KEY_SIGN); 1662296633Sdes execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL); 1663294332Sdes fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN, 166498684Sdes strerror(errno)); 166598684Sdes } 166698684Sdes close(from[1]); 166798684Sdes close(to[0]); 166898684Sdes 1669294332Sdes if ((b = sshbuf_new()) == NULL) 1670294332Sdes fatal("%s: sshbuf_new failed", __func__); 1671294332Sdes /* send # of sock, data to be signed */ 1672323136Sdes if ((r = sshbuf_put_u32(b, sock)) != 0 || 1673294332Sdes (r = sshbuf_put_string(b, data, datalen)) != 0) 1674294332Sdes fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1675294332Sdes if (ssh_msg_send(to[1], version, b) == -1) 1676294332Sdes fatal("%s: couldn't send request", __func__); 1677294332Sdes sshbuf_reset(b); 1678294332Sdes r = ssh_msg_recv(from[0], b); 167998684Sdes close(from[0]); 168098684Sdes close(to[1]); 1681294332Sdes if (r < 0) { 1682294332Sdes error("%s: no reply", __func__); 1683294332Sdes goto fail; 1684294332Sdes } 168598684Sdes 1686294332Sdes errno = 0; 1687294332Sdes while (waitpid(pid, &status, 0) < 0) { 1688294332Sdes if (errno != EINTR) { 1689294332Sdes error("%s: waitpid %ld: %s", 1690294332Sdes __func__, (long)pid, strerror(errno)); 1691294332Sdes goto fail; 1692294332Sdes } 1693294332Sdes } 1694294332Sdes if (!WIFEXITED(status)) { 1695294332Sdes error("%s: exited abnormally", __func__); 1696294332Sdes goto fail; 1697294332Sdes } 1698294332Sdes if (WEXITSTATUS(status) != 0) { 1699294332Sdes error("%s: exited with status %d", 1700294332Sdes __func__, WEXITSTATUS(status)); 1701294332Sdes goto fail; 1702294332Sdes } 1703294332Sdes if ((r = sshbuf_get_u8(b, &rversion)) != 0) { 1704294332Sdes error("%s: buffer error: %s", __func__, ssh_err(r)); 1705294332Sdes goto fail; 1706294332Sdes } 1707294332Sdes if (rversion != version) { 1708294332Sdes error("%s: bad version", __func__); 1709294332Sdes goto fail; 1710294332Sdes } 1711294332Sdes if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) { 1712294332Sdes error("%s: buffer error: %s", __func__, ssh_err(r)); 1713294332Sdes fail: 1714294332Sdes signal(SIGCHLD, osigchld); 1715294332Sdes sshbuf_free(b); 171698684Sdes return -1; 171798684Sdes } 1718294332Sdes signal(SIGCHLD, osigchld); 1719294332Sdes sshbuf_free(b); 172098684Sdes 172198684Sdes return 0; 172298684Sdes} 172398684Sdes 172476262Sgreenint 172576262Sgreenuserauth_hostbased(Authctxt *authctxt) 172669587Sgreen{ 1727294332Sdes struct ssh *ssh = active_state; 1728294332Sdes struct sshkey *private = NULL; 1729294332Sdes struct sshbuf *b = NULL; 173076262Sgreen const char *service; 1731294332Sdes u_char *sig = NULL, *keyblob = NULL; 1732294332Sdes char *fp = NULL, *chost = NULL, *lname = NULL; 1733294332Sdes size_t siglen = 0, keylen = 0; 1734294332Sdes int i, r, success = 0; 173576262Sgreen 1736294332Sdes if (authctxt->ktypes == NULL) { 1737294332Sdes authctxt->oktypes = xstrdup(options.hostbased_key_types); 1738294332Sdes authctxt->ktypes = authctxt->oktypes; 1739294332Sdes } 1740294332Sdes 1741294332Sdes /* 1742294332Sdes * Work through each listed type pattern in HostbasedKeyTypes, 1743294332Sdes * trying each hostkey that matches the type in turn. 1744294332Sdes */ 1745294332Sdes for (;;) { 1746294332Sdes if (authctxt->active_ktype == NULL) 1747294332Sdes authctxt->active_ktype = strsep(&authctxt->ktypes, ","); 1748294332Sdes if (authctxt->active_ktype == NULL || 1749294332Sdes *authctxt->active_ktype == '\0') 1750294332Sdes break; 1751294332Sdes debug3("%s: trying key type %s", __func__, 1752294332Sdes authctxt->active_ktype); 1753294332Sdes 1754294332Sdes /* check for a useful key */ 1755294332Sdes private = NULL; 1756294332Sdes for (i = 0; i < authctxt->sensitive->nkeys; i++) { 1757294332Sdes if (authctxt->sensitive->keys[i] == NULL || 1758294332Sdes authctxt->sensitive->keys[i]->type == KEY_RSA1 || 1759294332Sdes authctxt->sensitive->keys[i]->type == KEY_UNSPEC) 1760294332Sdes continue; 1761294332Sdes if (match_pattern_list( 1762294332Sdes sshkey_ssh_name(authctxt->sensitive->keys[i]), 1763294336Sdes authctxt->active_ktype, 0) != 1) 1764294332Sdes continue; 176576262Sgreen /* we take and free the key */ 1766294332Sdes private = authctxt->sensitive->keys[i]; 1767294332Sdes authctxt->sensitive->keys[i] = NULL; 176876262Sgreen break; 176976262Sgreen } 1770294332Sdes /* Found one */ 1771294332Sdes if (private != NULL) 1772294332Sdes break; 1773294332Sdes /* No more keys of this type; advance */ 1774294332Sdes authctxt->active_ktype = NULL; 177569587Sgreen } 1776294332Sdes if (private == NULL) { 1777294332Sdes free(authctxt->oktypes); 1778294332Sdes authctxt->oktypes = authctxt->ktypes = NULL; 1779294332Sdes authctxt->active_ktype = NULL; 1780113911Sdes debug("No more client hostkeys for hostbased authentication."); 1781294332Sdes goto out; 178269587Sgreen } 1783294332Sdes 1784294332Sdes if ((fp = sshkey_fingerprint(private, options.fingerprint_hash, 1785294332Sdes SSH_FP_DEFAULT)) == NULL) { 1786294332Sdes error("%s: sshkey_fingerprint failed", __func__); 1787294332Sdes goto out; 178876262Sgreen } 1789294332Sdes debug("%s: trying hostkey %s %s", 1790294332Sdes __func__, sshkey_ssh_name(private), fp); 1791294332Sdes 179292559Sdes /* figure out a name for the client host */ 1793294332Sdes if ((lname = get_local_name(packet_get_connection_in())) == NULL) { 1794294332Sdes error("%s: cannot get local ipaddr/name", __func__); 1795294332Sdes goto out; 179692559Sdes } 179792559Sdes 1798294332Sdes /* XXX sshbuf_put_stringf? */ 1799294332Sdes xasprintf(&chost, "%s.", lname); 1800294332Sdes debug2("%s: chost %s", __func__, chost); 1801294332Sdes 180276262Sgreen service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : 180376262Sgreen authctxt->service; 1804294332Sdes 180576262Sgreen /* construct data */ 1806294332Sdes if ((b = sshbuf_new()) == NULL) { 1807294332Sdes error("%s: sshbuf_new failed", __func__); 1808294332Sdes goto out; 1809294332Sdes } 1810294332Sdes if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) { 1811294332Sdes error("%s: sshkey_to_blob: %s", __func__, ssh_err(r)); 1812294332Sdes goto out; 1813294332Sdes } 1814294332Sdes if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 || 1815294332Sdes (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 || 1816294332Sdes (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 || 1817294332Sdes (r = sshbuf_put_cstring(b, service)) != 0 || 1818294332Sdes (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 || 1819294332Sdes (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 || 1820294332Sdes (r = sshbuf_put_string(b, keyblob, keylen)) != 0 || 1821294332Sdes (r = sshbuf_put_cstring(b, chost)) != 0 || 1822294332Sdes (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) { 1823294332Sdes error("%s: buffer error: %s", __func__, ssh_err(r)); 1824294332Sdes goto out; 1825294332Sdes } 1826294332Sdes 182776262Sgreen#ifdef DEBUG_PK 1828294332Sdes sshbuf_dump(b, stderr); 182976262Sgreen#endif 1830294332Sdes if (authctxt->sensitive->external_keysign) 1831294332Sdes r = ssh_keysign(private, &sig, &siglen, 1832294332Sdes sshbuf_ptr(b), sshbuf_len(b)); 1833294332Sdes else if ((r = sshkey_sign(private, &sig, &siglen, 1834296633Sdes sshbuf_ptr(b), sshbuf_len(b), NULL, datafellows)) != 0) 1835294332Sdes debug("%s: sshkey_sign: %s", __func__, ssh_err(r)); 1836294332Sdes if (r != 0) { 1837294332Sdes error("sign using hostkey %s %s failed", 1838294332Sdes sshkey_ssh_name(private), fp); 1839294332Sdes goto out; 184076262Sgreen } 1841294332Sdes if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 || 1842294332Sdes (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 || 1843294332Sdes (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 || 1844294332Sdes (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 || 1845294332Sdes (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 || 1846294332Sdes (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 || 1847294332Sdes (r = sshpkt_put_cstring(ssh, chost)) != 0 || 1848294332Sdes (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 || 1849294332Sdes (r = sshpkt_put_string(ssh, sig, siglen)) != 0 || 1850294332Sdes (r = sshpkt_send(ssh)) != 0) { 1851294332Sdes error("%s: packet error: %s", __func__, ssh_err(r)); 1852294332Sdes goto out; 1853294332Sdes } 1854294332Sdes success = 1; 1855294332Sdes 1856294332Sdes out: 1857294332Sdes if (sig != NULL) { 1858294332Sdes explicit_bzero(sig, siglen); 1859294332Sdes free(sig); 1860294332Sdes } 1861294332Sdes free(keyblob); 1862294332Sdes free(lname); 1863294332Sdes free(fp); 1864255767Sdes free(chost); 1865294332Sdes sshkey_free(private); 1866294332Sdes sshbuf_free(b); 186776262Sgreen 1868294332Sdes return success; 186969587Sgreen} 187069587Sgreen 187176262Sgreen/* find auth method */ 187276262Sgreen 187369587Sgreen/* 187469587Sgreen * given auth method name, if configurable options permit this method fill 187569587Sgreen * in auth_ident field and return true, otherwise return false. 187669587Sgreen */ 187792559Sdesstatic int 187869587Sgreenauthmethod_is_enabled(Authmethod *method) 187969587Sgreen{ 188069587Sgreen if (method == NULL) 188169587Sgreen return 0; 188269587Sgreen /* return false if options indicate this method is disabled */ 188369587Sgreen if (method->enabled == NULL || *method->enabled == 0) 188469587Sgreen return 0; 188569587Sgreen /* return false if batch mode is enabled but method needs interactive mode */ 188669587Sgreen if (method->batch_flag != NULL && *method->batch_flag != 0) 188769587Sgreen return 0; 188869587Sgreen return 1; 188969587Sgreen} 189069587Sgreen 189192559Sdesstatic Authmethod * 189269587Sgreenauthmethod_lookup(const char *name) 189369587Sgreen{ 189469587Sgreen Authmethod *method = NULL; 189569587Sgreen if (name != NULL) 189669587Sgreen for (method = authmethods; method->name != NULL; method++) 189769587Sgreen if (strcmp(name, method->name) == 0) 189869587Sgreen return method; 189969587Sgreen debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); 190069587Sgreen return NULL; 190169587Sgreen} 190269587Sgreen 190376262Sgreen/* XXX internal state */ 190476262Sgreenstatic Authmethod *current = NULL; 190576262Sgreenstatic char *supported = NULL; 190676262Sgreenstatic char *preferred = NULL; 190799063Sdes 190869587Sgreen/* 190969587Sgreen * Given the authentication method list sent by the server, return the 191069587Sgreen * next method we should try. If the server initially sends a nil list, 191176262Sgreen * use a built-in default list. 191276262Sgreen */ 191392559Sdesstatic Authmethod * 191469587Sgreenauthmethod_get(char *authlist) 191569587Sgreen{ 191676262Sgreen char *name = NULL; 191792559Sdes u_int next; 191876262Sgreen 191969587Sgreen /* Use a suitable default if we're passed a nil list. */ 192069587Sgreen if (authlist == NULL || strlen(authlist) == 0) 192176262Sgreen authlist = options.preferred_authentications; 192269587Sgreen 192376262Sgreen if (supported == NULL || strcmp(authlist, supported) != 0) { 192476262Sgreen debug3("start over, passed a different list %s", authlist); 1925255767Sdes free(supported); 192676262Sgreen supported = xstrdup(authlist); 192776262Sgreen preferred = options.preferred_authentications; 192876262Sgreen debug3("preferred %s", preferred); 192976262Sgreen current = NULL; 193076262Sgreen } else if (current != NULL && authmethod_is_enabled(current)) 193176262Sgreen return current; 193260573Skris 193376262Sgreen for (;;) { 193476262Sgreen if ((name = match_list(preferred, supported, &next)) == NULL) { 1935113911Sdes debug("No more authentication methods to try."); 193676262Sgreen current = NULL; 193776262Sgreen return NULL; 193876262Sgreen } 193976262Sgreen preferred += next; 194069587Sgreen debug3("authmethod_lookup %s", name); 194176262Sgreen debug3("remaining preferred: %s", preferred); 194276262Sgreen if ((current = authmethod_lookup(name)) != NULL && 194376262Sgreen authmethod_is_enabled(current)) { 194469587Sgreen debug3("authmethod_is_enabled %s", name); 1945113911Sdes debug("Next authentication method: %s", name); 1946255767Sdes free(name); 194776262Sgreen return current; 194860573Skris } 1949255767Sdes free(name); 195060573Skris } 195176262Sgreen} 195269587Sgreen 195392559Sdesstatic char * 195476262Sgreenauthmethods_get(void) 195576262Sgreen{ 195676262Sgreen Authmethod *method = NULL; 195792559Sdes Buffer b; 195892559Sdes char *list; 195969587Sgreen 196092559Sdes buffer_init(&b); 196176262Sgreen for (method = authmethods; method->name != NULL; method++) { 196276262Sgreen if (authmethod_is_enabled(method)) { 196392559Sdes if (buffer_len(&b) > 0) 196492559Sdes buffer_append(&b, ",", 1); 196592559Sdes buffer_append(&b, method->name, strlen(method->name)); 196676262Sgreen } 196776262Sgreen } 1968323129Sdes if ((list = sshbuf_dup_string(&b)) == NULL) 1969323129Sdes fatal("%s: sshbuf_dup_string failed", __func__); 197092559Sdes buffer_free(&b); 197192559Sdes return list; 197260573Skris} 1973192595Sdes 1974