| /* |
| * Copyright (c) 2000 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" |
| |
| #include <sys/types.h> |
| #include <sys/wait.h> |
| #include <sys/stat.h> |
| |
| #include "openbsd-compat/sys-queue.h" |
| |
| #include "ssh.h" |
| #include "ssh2.h" |
| #include "xmalloc.h" |
| #include "buffer.h" |
| #include "packet.h" |
| #include "compat.h" |
| #include "bufaux.h" |
| #include "cipher.h" |
| #include "kex.h" |
| #include "myproposal.h" |
| #include "sshconnect.h" |
| #include "authfile.h" |
| #include "dh.h" |
| #include "authfd.h" |
| #include "log.h" |
| #include "readconf.h" |
| #include "misc.h" |
| #include "match.h" |
| #include "dispatch.h" |
| #include "canohost.h" |
| #include "msg.h" |
| #include "pathnames.h" |
| |
| #ifdef GSSAPI |
| #include "ssh-gss.h" |
| #endif |
| |
| /* import */ |
| extern char *client_version_string; |
| extern char *server_version_string; |
| extern Options options; |
| |
| /* |
| * SSH2 key exchange |
| */ |
| |
| u_char *session_id2 = NULL; |
| u_int session_id2_len = 0; |
| |
| char *xxx_host; |
| struct sockaddr *xxx_hostaddr; |
| |
| Kex *xxx_kex = NULL; |
| |
| static int |
| verify_host_key_callback(Key *hostkey) |
| { |
| if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) |
| fatal("Host key verification failed."); |
| return 0; |
| } |
| |
| void |
| ssh_kex2(char *host, struct sockaddr *hostaddr) |
| { |
| Kex *kex; |
| |
| xxx_host = host; |
| xxx_hostaddr = hostaddr; |
| |
| if (options.ciphers == (char *)-1) { |
| logit("No valid ciphers for protocol version 2 given, using defaults."); |
| options.ciphers = NULL; |
| } |
| if (options.ciphers != NULL) { |
| myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
| myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; |
| } |
| myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
| compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); |
| myproposal[PROPOSAL_ENC_ALGS_STOC] = |
| compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); |
| if (options.compression) { |
| myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
| myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none"; |
| } else { |
| myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
| myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib"; |
| } |
| if (options.macs != NULL) { |
| myproposal[PROPOSAL_MAC_ALGS_CTOS] = |
| myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; |
| } |
| if (options.hostkeyalgorithms != NULL) |
| myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
| options.hostkeyalgorithms; |
| |
| if (options.rekey_limit) |
| packet_set_rekey_limit(options.rekey_limit); |
| |
| /* start key exchange */ |
| kex = kex_setup(myproposal); |
| kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; |
| kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client; |
| kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; |
| kex->kex[KEX_DH_GEX_SHA256] = kexgex_client; |
| kex->client_version_string=client_version_string; |
| kex->server_version_string=server_version_string; |
| kex->verify_host_key=&verify_host_key_callback; |
| |
| xxx_kex = kex; |
| |
| dispatch_run(DISPATCH_BLOCK, &kex->done, kex); |
| |
| session_id2 = kex->session_id; |
| session_id2_len = kex->session_id_len; |
| |
| #ifdef DEBUG_KEXDH |
| /* send 1st encrypted/maced/compressed message */ |
| packet_start(SSH2_MSG_IGNORE); |
| packet_put_cstring("markus"); |
| packet_send(); |
| packet_write_wait(); |
| #endif |
| } |
| |
| /* |
| * Authenticate user |
| */ |
| |
| typedef struct Authctxt Authctxt; |
| typedef struct Authmethod Authmethod; |
| typedef struct identity Identity; |
| typedef struct idlist Idlist; |
| |
| struct identity { |
| TAILQ_ENTRY(identity) next; |
| AuthenticationConnection *ac; /* set if agent supports key */ |
| Key *key; /* public/private key */ |
| char *filename; /* comment for agent-only keys */ |
| int tried; |
| int isprivate; /* key points to the private key */ |
| }; |
| TAILQ_HEAD(idlist, identity); |
| |
| struct Authctxt { |
| const char *server_user; |
| const char *local_user; |
| const char *host; |
| const char *service; |
| Authmethod *method; |
| int success; |
| char *authlist; |
| /* pubkey */ |
| Idlist keys; |
| AuthenticationConnection *agent; |
| /* hostbased */ |
| Sensitive *sensitive; |
| /* kbd-interactive */ |
| int info_req_seen; |
| /* generic */ |
| void *methoddata; |
| }; |
| struct Authmethod { |
| char *name; /* string to compare against server's list */ |
| int (*userauth)(Authctxt *authctxt); |
| int *enabled; /* flag in option struct that enables method */ |
| int *batch_flag; /* flag in option struct that disables method */ |
| }; |
| |
| void input_userauth_success(int, u_int32_t, void *); |
| void input_userauth_failure(int, u_int32_t, void *); |
| void input_userauth_banner(int, u_int32_t, void *); |
| void input_userauth_error(int, u_int32_t, void *); |
| void input_userauth_info_req(int, u_int32_t, void *); |
| void input_userauth_pk_ok(int, u_int32_t, void *); |
| void input_userauth_passwd_changereq(int, u_int32_t, void *); |
| |
| int userauth_none(Authctxt *); |
| int userauth_pubkey(Authctxt *); |
| int userauth_passwd(Authctxt *); |
| int userauth_kbdint(Authctxt *); |
| int userauth_hostbased(Authctxt *); |
| int userauth_kerberos(Authctxt *); |
| |
| #ifdef GSSAPI |
| int userauth_gssapi(Authctxt *authctxt); |
| void input_gssapi_response(int type, u_int32_t, void *); |
| void input_gssapi_token(int type, u_int32_t, void *); |
| void input_gssapi_hash(int type, u_int32_t, void *); |
| void input_gssapi_error(int, u_int32_t, void *); |
| void input_gssapi_errtok(int, u_int32_t, void *); |
| #endif |
| |
| void userauth(Authctxt *, char *); |
| |
| static int sign_and_send_pubkey(Authctxt *, Identity *); |
| static void pubkey_prepare(Authctxt *); |
| static void pubkey_cleanup(Authctxt *); |
| static Key *load_identity_file(char *); |
| |
| static Authmethod *authmethod_get(char *authlist); |
| static Authmethod *authmethod_lookup(const char *name); |
| static char *authmethods_get(void); |
| |
| Authmethod authmethods[] = { |
| #ifdef GSSAPI |
| {"gssapi-with-mic", |
| userauth_gssapi, |
| &options.gss_authentication, |
| NULL}, |
| #endif |
| {"hostbased", |
| userauth_hostbased, |
| &options.hostbased_authentication, |
| NULL}, |
| {"publickey", |
| userauth_pubkey, |
| &options.pubkey_authentication, |
| NULL}, |
| {"keyboard-interactive", |
| userauth_kbdint, |
| &options.kbd_interactive_authentication, |
| &options.batch_mode}, |
| {"password", |
| userauth_passwd, |
| &options.password_authentication, |
| &options.batch_mode}, |
| {"none", |
| userauth_none, |
| NULL, |
| NULL}, |
| {NULL, NULL, NULL, NULL} |
| }; |
| |
| void |
| ssh_userauth2(const char *local_user, const char *server_user, char *host, |
| Sensitive *sensitive) |
| { |
| Authctxt authctxt; |
| int type; |
| |
| if (options.challenge_response_authentication) |
| options.kbd_interactive_authentication = 1; |
| |
| packet_start(SSH2_MSG_SERVICE_REQUEST); |
| packet_put_cstring("ssh-userauth"); |
| packet_send(); |
| debug("SSH2_MSG_SERVICE_REQUEST sent"); |
| packet_write_wait(); |
| type = packet_read(); |
| if (type != SSH2_MSG_SERVICE_ACCEPT) |
| fatal("Server denied authentication request: %d", type); |
| if (packet_remaining() > 0) { |
| char *reply = packet_get_string(NULL); |
| debug2("service_accept: %s", reply); |
| xfree(reply); |
| } else { |
| debug2("buggy server: service_accept w/o service"); |
| } |
| packet_check_eom(); |
| debug("SSH2_MSG_SERVICE_ACCEPT received"); |
| |
| if (options.preferred_authentications == NULL) |
| options.preferred_authentications = authmethods_get(); |
| |
| /* setup authentication context */ |
| memset(&authctxt, 0, sizeof(authctxt)); |
| pubkey_prepare(&authctxt); |
| authctxt.server_user = server_user; |
| authctxt.local_user = local_user; |
| authctxt.host = host; |
| authctxt.service = "ssh-connection"; /* service name */ |
| authctxt.success = 0; |
| authctxt.method = authmethod_lookup("none"); |
| authctxt.authlist = NULL; |
| authctxt.methoddata = NULL; |
| authctxt.sensitive = sensitive; |
| authctxt.info_req_seen = 0; |
| if (authctxt.method == NULL) |
| fatal("ssh_userauth2: internal error: cannot send userauth none request"); |
| |
| /* initial userauth request */ |
| userauth_none(&authctxt); |
| |
| dispatch_init(&input_userauth_error); |
| dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); |
| dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); |
| dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); |
| dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ |
| |
| pubkey_cleanup(&authctxt); |
| dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); |
| |
| debug("Authentication succeeded (%s).", authctxt.method->name); |
| } |
| |
| void |
| userauth(Authctxt *authctxt, char *authlist) |
| { |
| if (authctxt->methoddata) { |
| xfree(authctxt->methoddata); |
| authctxt->methoddata = NULL; |
| } |
| if (authlist == NULL) { |
| authlist = authctxt->authlist; |
| } else { |
| if (authctxt->authlist) |
| xfree(authctxt->authlist); |
| authctxt->authlist = authlist; |
| } |
| for (;;) { |
| Authmethod *method = authmethod_get(authlist); |
| if (method == NULL) |
| fatal("Permission denied (%s).", authlist); |
| authctxt->method = method; |
| |
| /* reset the per method handler */ |
| dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, |
| SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); |
| |
| /* and try new method */ |
| if (method->userauth(authctxt) != 0) { |
| debug2("we sent a %s packet, wait for reply", method->name); |
| break; |
| } else { |
| debug2("we did not send a packet, disable method"); |
| method->enabled = NULL; |
| } |
| } |
| } |
| |
| void |
| input_userauth_error(int type, u_int32_t seq, void *ctxt) |
| { |
| fatal("input_userauth_error: bad message during authentication: " |
| "type %d", type); |
| } |
| |
| void |
| input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
| { |
| char *msg, *lang; |
| |
| debug3("input_userauth_banner"); |
| msg = packet_get_string(NULL); |
| lang = packet_get_string(NULL); |
| if (options.log_level > SYSLOG_LEVEL_QUIET) |
| fprintf(stderr, "%s", msg); |
| xfree(msg); |
| xfree(lang); |
| } |
| |
| void |
| input_userauth_success(int type, u_int32_t seq, void *ctxt) |
| { |
| Authctxt *authctxt = ctxt; |
| if (authctxt == NULL) |
| fatal("input_userauth_success: no authentication context"); |
| if (authctxt->authlist) { |
| xfree(authctxt->authlist); |
| authctxt->authlist = NULL; |
| } |
| if (authctxt->methoddata) { |
| xfree(authctxt->methoddata); |
| authctxt->methoddata = NULL; |
| } |
| authctxt->success = 1; /* break out */ |
| } |
| |
| void |
| input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
| { |
| Authctxt *authctxt = ctxt; |
| char *authlist = NULL; |
| int partial; |
| |
| if (authctxt == NULL) |
| fatal("input_userauth_failure: no authentication context"); |
| |
| authlist = packet_get_string(NULL); |
| partial = packet_get_char(); |
| packet_check_eom(); |
| |
| if (partial != 0) |
| logit("Authenticated with partial success."); |
| debug("Authentications that can continue: %s", authlist); |
| |
| userauth(authctxt, authlist); |
| } |
| void |
| input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
| { |
| Authctxt *authctxt = ctxt; |
| Key *key = NULL; |
| Identity *id = NULL; |
| Buffer b; |
| int pktype, sent = 0; |
| u_int alen, blen; |
| char *pkalg, *fp; |
| u_char *pkblob; |
| |
| if (authctxt == NULL) |
| fatal("input_userauth_pk_ok: no authentication context"); |
| if (datafellows & SSH_BUG_PKOK) { |
| /* this is similar to SSH_BUG_PKAUTH */ |
| debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); |
| pkblob = packet_get_string(&blen); |
| buffer_init(&b); |
| buffer_append(&b, pkblob, blen); |
| pkalg = buffer_get_string(&b, &alen); |
| buffer_free(&b); |
| } else { |
| pkalg = packet_get_string(&alen); |
| pkblob = packet_get_string(&blen); |
| } |
| packet_check_eom(); |
| |
| debug("Server accepts key: pkalg %s blen %u", pkalg, blen); |
| |
| if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
| debug("unknown pkalg %s", pkalg); |
| goto done; |
| } |
| if ((key = key_from_blob(pkblob, blen)) == NULL) { |
| debug("no key from blob. pkalg %s", pkalg); |
| goto done; |
| } |
| if (key->type != pktype) { |
| error("input_userauth_pk_ok: type mismatch " |
| "for decoded key (received %d, expected %d)", |
| key->type, pktype); |
| goto done; |
| } |
| fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); |
| debug2("input_userauth_pk_ok: fp %s", fp); |
| xfree(fp); |
| |
| /* |
| * search keys in the reverse order, because last candidate has been |
| * moved to the end of the queue. this also avoids confusion by |
| * duplicate keys |
| */ |
| TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) { |
| if (key_equal(key, id->key)) { |
| sent = sign_and_send_pubkey(authctxt, id); |
| break; |
| } |
| } |
| done: |
| if (key != NULL) |
| key_free(key); |
| xfree(pkalg); |
| xfree(pkblob); |
| |
| /* try another method if we did not send a packet */ |
| if (sent == 0) |
| userauth(authctxt, NULL); |
| } |
| |
| #ifdef GSSAPI |
| int |
| userauth_gssapi(Authctxt *authctxt) |
| { |
| Gssctxt *gssctxt = NULL; |
| static gss_OID_set gss_supported = NULL; |
| static u_int mech = 0; |
| OM_uint32 min; |
| int ok = 0; |
| |
| /* Try one GSSAPI method at a time, rather than sending them all at |
| * once. */ |
| |
| if (gss_supported == NULL) |
| gss_indicate_mechs(&min, &gss_supported); |
| |
| /* Check to see if the mechanism is usable before we offer it */ |
| while (mech < gss_supported->count && !ok) { |
| if (gssctxt) |
| ssh_gssapi_delete_ctx(&gssctxt); |
| ssh_gssapi_build_ctx(&gssctxt); |
| ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]); |
| |
| /* My DER encoding requires length<128 */ |
| if (gss_supported->elements[mech].length < 128 && |
| !GSS_ERROR(ssh_gssapi_import_name(gssctxt, |
| authctxt->host))) { |
| ok = 1; /* Mechanism works */ |
| } else { |
| mech++; |
| } |
| } |
| |
| if (!ok) |
| return 0; |
| |
| authctxt->methoddata=(void *)gssctxt; |
| |
| packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| packet_put_cstring(authctxt->server_user); |
| packet_put_cstring(authctxt->service); |
| packet_put_cstring(authctxt->method->name); |
| |
| packet_put_int(1); |
| |
| packet_put_int((gss_supported->elements[mech].length) + 2); |
| packet_put_char(SSH_GSS_OIDTYPE); |
| packet_put_char(gss_supported->elements[mech].length); |
| packet_put_raw(gss_supported->elements[mech].elements, |
| gss_supported->elements[mech].length); |
| |
| packet_send(); |
| |
| dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); |
| dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); |
| dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); |
| dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); |
| |
| mech++; /* Move along to next candidate */ |
| |
| return 1; |
| } |
| |
| static OM_uint32 |
| process_gssapi_token(void *ctxt, gss_buffer_t recv_tok) |
| { |
| Authctxt *authctxt = ctxt; |
| Gssctxt *gssctxt = authctxt->methoddata; |
| gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; |
| gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; |
| gss_buffer_desc gssbuf; |
| OM_uint32 status, ms, flags; |
| Buffer b; |
| |
| status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, |
| recv_tok, &send_tok, &flags); |
| |
| if (send_tok.length > 0) { |
| if (GSS_ERROR(status)) |
| packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); |
| else |
| packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); |
| |
| packet_put_string(send_tok.value, send_tok.length); |
| packet_send(); |
| gss_release_buffer(&ms, &send_tok); |
| } |
| |
| if (status == GSS_S_COMPLETE) { |
| /* send either complete or MIC, depending on mechanism */ |
| if (!(flags & GSS_C_INTEG_FLAG)) { |
| packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); |
| packet_send(); |
| } else { |
| ssh_gssapi_buildmic(&b, authctxt->server_user, |
| authctxt->service, "gssapi-with-mic"); |
| |
| gssbuf.value = buffer_ptr(&b); |
| gssbuf.length = buffer_len(&b); |
| |
| status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic); |
| |
| if (!GSS_ERROR(status)) { |
| packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC); |
| packet_put_string(mic.value, mic.length); |
| |
| packet_send(); |
| } |
| |
| buffer_free(&b); |
| gss_release_buffer(&ms, &mic); |
| } |
| } |
| |
| return status; |
| } |
| |
| void |
| input_gssapi_response(int type, u_int32_t plen, void *ctxt) |
| { |
| Authctxt *authctxt = ctxt; |
| Gssctxt *gssctxt; |
| int oidlen; |
| char *oidv; |
| |
| if (authctxt == NULL) |
| fatal("input_gssapi_response: no authentication context"); |
| gssctxt = authctxt->methoddata; |
| |
| /* Setup our OID */ |
| oidv = packet_get_string(&oidlen); |
| |
| if (oidlen <= 2 || |
| oidv[0] != SSH_GSS_OIDTYPE || |
| oidv[1] != oidlen - 2) { |
| xfree(oidv); |
| debug("Badly encoded mechanism OID received"); |
| userauth(authctxt, NULL); |
| return; |
| } |
| |
| if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) |
| fatal("Server returned different OID than expected"); |
| |
| packet_check_eom(); |
| |
| xfree(oidv); |
| |
| if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) { |
| /* Start again with next method on list */ |
| debug("Trying to start again"); |
| userauth(authctxt, NULL); |
| return; |
| } |
| } |
| |
| void |
| input_gssapi_token(int type, u_int32_t plen, void *ctxt) |
| { |
| Authctxt *authctxt = ctxt; |
| gss_buffer_desc recv_tok; |
| OM_uint32 status; |
| u_int slen; |
| |
| if (authctxt == NULL) |
| fatal("input_gssapi_response: no authentication context"); |
| |
| recv_tok.value = packet_get_string(&slen); |
| recv_tok.length = slen; /* safe typecast */ |
| |
| packet_check_eom(); |
| |
| status = process_gssapi_token(ctxt, &recv_tok); |
| |
| xfree(recv_tok.value); |
| |
| if (GSS_ERROR(status)) { |
| /* Start again with the next method in the list */ |
| userauth(authctxt, NULL); |
| return; |
| } |
| } |
| |
| void |
| input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) |
| { |
| Authctxt *authctxt = ctxt; |
| Gssctxt *gssctxt; |
| gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; |
| gss_buffer_desc recv_tok; |
| OM_uint32 status, ms; |
| u_int len; |
| |
| if (authctxt == NULL) |
| fatal("input_gssapi_response: no authentication context"); |
| gssctxt = authctxt->methoddata; |
| |
| recv_tok.value = packet_get_string(&len); |
| recv_tok.length = len; |
| |
| packet_check_eom(); |
| |
| /* Stick it into GSSAPI and see what it says */ |
| status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, |
| &recv_tok, &send_tok, NULL); |
| |
| xfree(recv_tok.value); |
| gss_release_buffer(&ms, &send_tok); |
| |
| /* Server will be returning a failed packet after this one */ |
| } |
| |
| void |
| input_gssapi_error(int type, u_int32_t plen, void *ctxt) |
| { |
| OM_uint32 maj, min; |
| char *msg; |
| char *lang; |
| |
| maj=packet_get_int(); |
| min=packet_get_int(); |
| msg=packet_get_string(NULL); |
| lang=packet_get_string(NULL); |
| |
| packet_check_eom(); |
| |
| debug("Server GSSAPI Error:\n%s", msg); |
| xfree(msg); |
| xfree(lang); |
| } |
| #endif /* GSSAPI */ |
| |
| int |
| userauth_none(Authctxt *authctxt) |
| { |
| /* initial userauth request */ |
| packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| packet_put_cstring(authctxt->server_user); |
| packet_put_cstring(authctxt->service); |
| packet_put_cstring(authctxt->method->name); |
| packet_send(); |
| return 1; |
| } |
| |
| int |
| userauth_passwd(Authctxt *authctxt) |
| { |
| static int attempt = 0; |
| char prompt[150]; |
| char *password; |
| |
| if (attempt++ >= options.number_of_password_prompts) |
| return 0; |
| |
| if (attempt != 1) |
| error("Permission denied, please try again."); |
| |
| snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", |
| authctxt->server_user, authctxt->host); |
| password = read_passphrase(prompt, 0); |
| packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| packet_put_cstring(authctxt->server_user); |
| packet_put_cstring(authctxt->service); |
| packet_put_cstring(authctxt->method->name); |
| packet_put_char(0); |
| packet_put_cstring(password); |
| memset(password, 0, strlen(password)); |
| xfree(password); |
| packet_add_padding(64); |
| packet_send(); |
| |
| dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
| &input_userauth_passwd_changereq); |
| |
| return 1; |
| } |
| /* |
| * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST |
| */ |
| void |
| input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) |
| { |
| Authctxt *authctxt = ctxt; |
| char *info, *lang, *password = NULL, *retype = NULL; |
| char prompt[150]; |
| |
| debug2("input_userauth_passwd_changereq"); |
| |
| if (authctxt == NULL) |
| fatal("input_userauth_passwd_changereq: " |
| "no authentication context"); |
| |
| info = packet_get_string(NULL); |
| lang = packet_get_string(NULL); |
| if (strlen(info) > 0) |
| logit("%s", info); |
| xfree(info); |
| xfree(lang); |
| packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| packet_put_cstring(authctxt->server_user); |
| packet_put_cstring(authctxt->service); |
| packet_put_cstring(authctxt->method->name); |
| packet_put_char(1); /* additional info */ |
| snprintf(prompt, sizeof(prompt), |
| "Enter %.30s@%.128s's old password: ", |
| authctxt->server_user, authctxt->host); |
| password = read_passphrase(prompt, 0); |
| packet_put_cstring(password); |
| memset(password, 0, strlen(password)); |
| xfree(password); |
| password = NULL; |
| while (password == NULL) { |
| snprintf(prompt, sizeof(prompt), |
| "Enter %.30s@%.128s's new password: ", |
| authctxt->server_user, authctxt->host); |
| password = read_passphrase(prompt, RP_ALLOW_EOF); |
| if (password == NULL) { |
| /* bail out */ |
| return; |
| } |
| snprintf(prompt, sizeof(prompt), |
| "Retype %.30s@%.128s's new password: ", |
| authctxt->server_user, authctxt->host); |
| retype = read_passphrase(prompt, 0); |
| if (strcmp(password, retype) != 0) { |
| memset(password, 0, strlen(password)); |
| xfree(password); |
| logit("Mismatch; try again, EOF to quit."); |
| password = NULL; |
| } |
| memset(retype, 0, strlen(retype)); |
| xfree(retype); |
| } |
| packet_put_cstring(password); |
| memset(password, 0, strlen(password)); |
| xfree(password); |
| packet_add_padding(64); |
| packet_send(); |
| |
| dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
| &input_userauth_passwd_changereq); |
| } |
| |
| static int |
| identity_sign(Identity *id, u_char **sigp, u_int *lenp, |
| u_char *data, u_int datalen) |
| { |
| Key *prv; |
| int ret; |
| |
| /* the agent supports this key */ |
| if (id->ac) |
| return (ssh_agent_sign(id->ac, id->key, sigp, lenp, |
| data, datalen)); |
| /* |
| * we have already loaded the private key or |
| * the private key is stored in external hardware |
| */ |
| if (id->isprivate || (id->key->flags & KEY_FLAG_EXT)) |
| return (key_sign(id->key, sigp, lenp, data, datalen)); |
| /* load the private key from the file */ |
| if ((prv = load_identity_file(id->filename)) == NULL) |
| return (-1); |
| ret = key_sign(prv, sigp, lenp, data, datalen); |
| key_free(prv); |
| return (ret); |
| } |
| |
| static int |
| sign_and_send_pubkey(Authctxt *authctxt, Identity *id) |
| { |
| Buffer b; |
| u_char *blob, *signature; |
| u_int bloblen, slen; |
| u_int skip = 0; |
| int ret = -1; |
| int have_sig = 1; |
| |
| debug3("sign_and_send_pubkey"); |
| |
| if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
| /* we cannot handle this key */ |
| debug3("sign_and_send_pubkey: cannot handle key"); |
| return 0; |
| } |
| /* data to be signed */ |
| buffer_init(&b); |
| if (datafellows & SSH_OLD_SESSIONID) { |
| buffer_append(&b, session_id2, session_id2_len); |
| skip = session_id2_len; |
| } else { |
| buffer_put_string(&b, session_id2, session_id2_len); |
| skip = buffer_len(&b); |
| } |
| buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
| buffer_put_cstring(&b, authctxt->server_user); |
| buffer_put_cstring(&b, |
| datafellows & SSH_BUG_PKSERVICE ? |
| "ssh-userauth" : |
| authctxt->service); |
| if (datafellows & SSH_BUG_PKAUTH) { |
| buffer_put_char(&b, have_sig); |
| } else { |
| buffer_put_cstring(&b, authctxt->method->name); |
| buffer_put_char(&b, have_sig); |
| buffer_put_cstring(&b, key_ssh_name(id->key)); |
| } |
| buffer_put_string(&b, blob, bloblen); |
| |
| /* generate signature */ |
| ret = identity_sign(id, &signature, &slen, |
| buffer_ptr(&b), buffer_len(&b)); |
| if (ret == -1) { |
| xfree(blob); |
| buffer_free(&b); |
| return 0; |
| } |
| #ifdef DEBUG_PK |
| buffer_dump(&b); |
| #endif |
| if (datafellows & SSH_BUG_PKSERVICE) { |
| buffer_clear(&b); |
| buffer_append(&b, session_id2, session_id2_len); |
| skip = session_id2_len; |
| buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
| buffer_put_cstring(&b, authctxt->server_user); |
| buffer_put_cstring(&b, authctxt->service); |
| buffer_put_cstring(&b, authctxt->method->name); |
| buffer_put_char(&b, have_sig); |
| if (!(datafellows & SSH_BUG_PKAUTH)) |
| buffer_put_cstring(&b, key_ssh_name(id->key)); |
| buffer_put_string(&b, blob, bloblen); |
| } |
| xfree(blob); |
| |
| /* append signature */ |
| buffer_put_string(&b, signature, slen); |
| xfree(signature); |
| |
| /* skip session id and packet type */ |
| if (buffer_len(&b) < skip + 1) |
| fatal("userauth_pubkey: internal error"); |
| buffer_consume(&b, skip + 1); |
| |
| /* put remaining data from buffer into packet */ |
| packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| packet_put_raw(buffer_ptr(&b), buffer_len(&b)); |
| buffer_free(&b); |
| packet_send(); |
| |
| return 1; |
| } |
| |
| static int |
| send_pubkey_test(Authctxt *authctxt, Identity *id) |
| { |
| u_char *blob; |
| u_int bloblen, have_sig = 0; |
| |
| debug3("send_pubkey_test"); |
| |
| if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
| /* we cannot handle this key */ |
| debug3("send_pubkey_test: cannot handle key"); |
| return 0; |
| } |
| /* register callback for USERAUTH_PK_OK message */ |
| dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
| |
| packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| packet_put_cstring(authctxt->server_user); |
| packet_put_cstring(authctxt->service); |
| packet_put_cstring(authctxt->method->name); |
| packet_put_char(have_sig); |
| if (!(datafellows & SSH_BUG_PKAUTH)) |
| packet_put_cstring(key_ssh_name(id->key)); |
| packet_put_string(blob, bloblen); |
| xfree(blob); |
| packet_send(); |
| return 1; |
| } |
| |
| static Key * |
| load_identity_file(char *filename) |
| { |
| Key *private; |
| char prompt[300], *passphrase; |
| int quit, i; |
| struct stat st; |
| |
| if (stat(filename, &st) < 0) { |
| debug3("no such identity: %s", filename); |
| return NULL; |
| } |
| private = key_load_private_type(KEY_UNSPEC, filename, "", NULL); |
| if (private == NULL) { |
| if (options.batch_mode) |
| return NULL; |
| snprintf(prompt, sizeof prompt, |
| "Enter passphrase for key '%.100s': ", filename); |
| for (i = 0; i < options.number_of_password_prompts; i++) { |
| passphrase = read_passphrase(prompt, 0); |
| if (strcmp(passphrase, "") != 0) { |
| private = key_load_private_type(KEY_UNSPEC, filename, |
| passphrase, NULL); |
| quit = 0; |
| } else { |
| debug2("no passphrase given, try next key"); |
| quit = 1; |
| } |
| memset(passphrase, 0, strlen(passphrase)); |
| xfree(passphrase); |
| if (private != NULL || quit) |
| break; |
| debug2("bad passphrase given, try again..."); |
| } |
| } |
| return private; |
| } |
| |
| /* |
| * try keys in the following order: |
| * 1. agent keys that are found in the config file |
| * 2. other agent keys |
| * 3. keys that are only listed in the config file |
| */ |
| static void |
| pubkey_prepare(Authctxt *authctxt) |
| { |
| Identity *id; |
| Idlist agent, files, *preferred; |
| Key *key; |
| AuthenticationConnection *ac; |
| char *comment; |
| int i, found; |
| |
| TAILQ_INIT(&agent); /* keys from the agent */ |
| TAILQ_INIT(&files); /* keys from the config file */ |
| preferred = &authctxt->keys; |
| TAILQ_INIT(preferred); /* preferred order of keys */ |
| |
| /* list of keys stored in the filesystem */ |
| for (i = 0; i < options.num_identity_files; i++) { |
| key = options.identity_keys[i]; |
| if (key && key->type == KEY_RSA1) |
| continue; |
| options.identity_keys[i] = NULL; |
| id = xmalloc(sizeof(*id)); |
| memset(id, 0, sizeof(*id)); |
| id->key = key; |
| id->filename = xstrdup(options.identity_files[i]); |
| TAILQ_INSERT_TAIL(&files, id, next); |
| } |
| /* list of keys supported by the agent */ |
| if ((ac = ssh_get_authentication_connection())) { |
| for (key = ssh_get_first_identity(ac, &comment, 2); |
| key != NULL; |
| key = ssh_get_next_identity(ac, &comment, 2)) { |
| found = 0; |
| TAILQ_FOREACH(id, &files, next) { |
| /* agent keys from the config file are preferred */ |
| if (key_equal(key, id->key)) { |
| key_free(key); |
| xfree(comment); |
| TAILQ_REMOVE(&files, id, next); |
| TAILQ_INSERT_TAIL(preferred, id, next); |
| id->ac = ac; |
| found = 1; |
| break; |
| } |
| } |
| if (!found && !options.identities_only) { |
| id = xmalloc(sizeof(*id)); |
| memset(id, 0, sizeof(*id)); |
| id->key = key; |
| id->filename = comment; |
| id->ac = ac; |
| TAILQ_INSERT_TAIL(&agent, id, next); |
| } |
| } |
| /* append remaining agent keys */ |
| for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { |
| TAILQ_REMOVE(&agent, id, next); |
| TAILQ_INSERT_TAIL(preferred, id, next); |
| } |
| authctxt->agent = ac; |
| } |
| /* append remaining keys from the config file */ |
| for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { |
| TAILQ_REMOVE(&files, id, next); |
| TAILQ_INSERT_TAIL(preferred, id, next); |
| } |
| TAILQ_FOREACH(id, preferred, next) { |
| debug2("key: %s (%p)", id->filename, id->key); |
| } |
| } |
| |
| static void |
| pubkey_cleanup(Authctxt *authctxt) |
| { |
| Identity *id; |
| |
| if (authctxt->agent != NULL) |
| ssh_close_authentication_connection(authctxt->agent); |
| for (id = TAILQ_FIRST(&authctxt->keys); id; |
| id = TAILQ_FIRST(&authctxt->keys)) { |
| TAILQ_REMOVE(&authctxt->keys, id, next); |
| if (id->key) |
| key_free(id->key); |
| if (id->filename) |
| xfree(id->filename); |
| xfree(id); |
| } |
| } |
| |
| int |
| userauth_pubkey(Authctxt *authctxt) |
| { |
| Identity *id; |
| int sent = 0; |
| |
| while ((id = TAILQ_FIRST(&authctxt->keys))) { |
| if (id->tried++) |
| return (0); |
| /* move key to the end of the queue */ |
| TAILQ_REMOVE(&authctxt->keys, id, next); |
| TAILQ_INSERT_TAIL(&authctxt->keys, id, next); |
| /* |
| * send a test message if we have the public key. for |
| * encrypted keys we cannot do this and have to load the |
| * private key instead |
| */ |
| if (id->key && id->key->type != KEY_RSA1) { |
| debug("Offering public key: %s", id->filename); |
| sent = send_pubkey_test(authctxt, id); |
| } else if (id->key == NULL) { |
| debug("Trying private key: %s", id->filename); |
| id->key = load_identity_file(id->filename); |
| if (id->key != NULL) { |
| id->isprivate = 1; |
| sent = sign_and_send_pubkey(authctxt, id); |
| key_free(id->key); |
| id->key = NULL; |
| } |
| } |
| if (sent) |
| return (sent); |
| } |
| return (0); |
| } |
| |
| /* |
| * Send userauth request message specifying keyboard-interactive method. |
| */ |
| int |
| userauth_kbdint(Authctxt *authctxt) |
| { |
| static int attempt = 0; |
| |
| if (attempt++ >= options.number_of_password_prompts) |
| return 0; |
| /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ |
| if (attempt > 1 && !authctxt->info_req_seen) { |
| debug3("userauth_kbdint: disable: no info_req_seen"); |
| dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); |
| return 0; |
| } |
| |
| debug2("userauth_kbdint"); |
| packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| packet_put_cstring(authctxt->server_user); |
| packet_put_cstring(authctxt->service); |
| packet_put_cstring(authctxt->method->name); |
| packet_put_cstring(""); /* lang */ |
| packet_put_cstring(options.kbd_interactive_devices ? |
| options.kbd_interactive_devices : ""); |
| packet_send(); |
| |
| dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); |
| return 1; |
| } |
| |
| /* |
| * parse INFO_REQUEST, prompt user and send INFO_RESPONSE |
| */ |
| void |
| input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
| { |
| Authctxt *authctxt = ctxt; |
| char *name, *inst, *lang, *prompt, *response; |
| u_int num_prompts, i; |
| int echo = 0; |
| |
| debug2("input_userauth_info_req"); |
| |
| if (authctxt == NULL) |
| fatal("input_userauth_info_req: no authentication context"); |
| |
| authctxt->info_req_seen = 1; |
| |
| name = packet_get_string(NULL); |
| inst = packet_get_string(NULL); |
| lang = packet_get_string(NULL); |
| if (strlen(name) > 0) |
| logit("%s", name); |
| if (strlen(inst) > 0) |
| logit("%s", inst); |
| xfree(name); |
| xfree(inst); |
| xfree(lang); |
| |
| num_prompts = packet_get_int(); |
| /* |
| * Begin to build info response packet based on prompts requested. |
| * We commit to providing the correct number of responses, so if |
| * further on we run into a problem that prevents this, we have to |
| * be sure and clean this up and send a correct error response. |
| */ |
| packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); |
| packet_put_int(num_prompts); |
| |
| debug2("input_userauth_info_req: num_prompts %d", num_prompts); |
| for (i = 0; i < num_prompts; i++) { |
| prompt = packet_get_string(NULL); |
| echo = packet_get_char(); |
| |
| response = read_passphrase(prompt, echo ? RP_ECHO : 0); |
| |
| packet_put_cstring(response); |
| memset(response, 0, strlen(response)); |
| xfree(response); |
| xfree(prompt); |
| } |
| packet_check_eom(); /* done with parsing incoming message. */ |
| |
| packet_add_padding(64); |
| packet_send(); |
| } |
| |
| static int |
| ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
| u_char *data, u_int datalen) |
| { |
| Buffer b; |
| struct stat st; |
| pid_t pid; |
| int to[2], from[2], status, version = 2; |
| |
| debug2("ssh_keysign called"); |
| |
| if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { |
| error("ssh_keysign: no installed: %s", strerror(errno)); |
| return -1; |
| } |
| if (fflush(stdout) != 0) |
| error("ssh_keysign: fflush: %s", strerror(errno)); |
| if (pipe(to) < 0) { |
| error("ssh_keysign: pipe: %s", strerror(errno)); |
| return -1; |
| } |
| if (pipe(from) < 0) { |
| error("ssh_keysign: pipe: %s", strerror(errno)); |
| return -1; |
| } |
| if ((pid = fork()) < 0) { |
| error("ssh_keysign: fork: %s", strerror(errno)); |
| return -1; |
| } |
| if (pid == 0) { |
| seteuid(getuid()); |
| setuid(getuid()); |
| close(from[0]); |
| if (dup2(from[1], STDOUT_FILENO) < 0) |
| fatal("ssh_keysign: dup2: %s", strerror(errno)); |
| close(to[1]); |
| if (dup2(to[0], STDIN_FILENO) < 0) |
| fatal("ssh_keysign: dup2: %s", strerror(errno)); |
| close(from[1]); |
| close(to[0]); |
| execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); |
| fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, |
| strerror(errno)); |
| } |
| close(from[1]); |
| close(to[0]); |
| |
| buffer_init(&b); |
| buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ |
| buffer_put_string(&b, data, datalen); |
| if (ssh_msg_send(to[1], version, &b) == -1) |
| fatal("ssh_keysign: couldn't send request"); |
| |
| if (ssh_msg_recv(from[0], &b) < 0) { |
| error("ssh_keysign: no reply"); |
| buffer_free(&b); |
| return -1; |
| } |
| close(from[0]); |
| close(to[1]); |
| |
| while (waitpid(pid, &status, 0) < 0) |
| if (errno != EINTR) |
| break; |
| |
| if (buffer_get_char(&b) != version) { |
| error("ssh_keysign: bad version"); |
| buffer_free(&b); |
| return -1; |
| } |
| *sigp = buffer_get_string(&b, lenp); |
| buffer_free(&b); |
| |
| return 0; |
| } |
| |
| int |
| userauth_hostbased(Authctxt *authctxt) |
| { |
| Key *private = NULL; |
| Sensitive *sensitive = authctxt->sensitive; |
| Buffer b; |
| u_char *signature, *blob; |
| char *chost, *pkalg, *p; |
| const char *service; |
| u_int blen, slen; |
| int ok, i, len, found = 0; |
| |
| /* check for a useful key */ |
| for (i = 0; i < sensitive->nkeys; i++) { |
| private = sensitive->keys[i]; |
| if (private && private->type != KEY_RSA1) { |
| found = 1; |
| /* we take and free the key */ |
| sensitive->keys[i] = NULL; |
| break; |
| } |
| } |
| if (!found) { |
| debug("No more client hostkeys for hostbased authentication."); |
| return 0; |
| } |
| if (key_to_blob(private, &blob, &blen) == 0) { |
| key_free(private); |
| return 0; |
| } |
| /* figure out a name for the client host */ |
| p = get_local_name(packet_get_connection_in()); |
| if (p == NULL) { |
| error("userauth_hostbased: cannot get local ipaddr/name"); |
| key_free(private); |
| return 0; |
| } |
| len = strlen(p) + 2; |
| chost = xmalloc(len); |
| strlcpy(chost, p, len); |
| strlcat(chost, ".", len); |
| debug2("userauth_hostbased: chost %s", chost); |
| xfree(p); |
| |
| service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : |
| authctxt->service; |
| pkalg = xstrdup(key_ssh_name(private)); |
| buffer_init(&b); |
| /* construct data */ |
| buffer_put_string(&b, session_id2, session_id2_len); |
| buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
| buffer_put_cstring(&b, authctxt->server_user); |
| buffer_put_cstring(&b, service); |
| buffer_put_cstring(&b, authctxt->method->name); |
| buffer_put_cstring(&b, pkalg); |
| buffer_put_string(&b, blob, blen); |
| buffer_put_cstring(&b, chost); |
| buffer_put_cstring(&b, authctxt->local_user); |
| #ifdef DEBUG_PK |
| buffer_dump(&b); |
| #endif |
| if (sensitive->external_keysign) |
| ok = ssh_keysign(private, &signature, &slen, |
| buffer_ptr(&b), buffer_len(&b)); |
| else |
| ok = key_sign(private, &signature, &slen, |
| buffer_ptr(&b), buffer_len(&b)); |
| key_free(private); |
| buffer_free(&b); |
| if (ok != 0) { |
| error("key_sign failed"); |
| xfree(chost); |
| xfree(pkalg); |
| return 0; |
| } |
| packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| packet_put_cstring(authctxt->server_user); |
| packet_put_cstring(authctxt->service); |
| packet_put_cstring(authctxt->method->name); |
| packet_put_cstring(pkalg); |
| packet_put_string(blob, blen); |
| packet_put_cstring(chost); |
| packet_put_cstring(authctxt->local_user); |
| packet_put_string(signature, slen); |
| memset(signature, 's', slen); |
| xfree(signature); |
| xfree(chost); |
| xfree(pkalg); |
| |
| packet_send(); |
| return 1; |
| } |
| |
| /* find auth method */ |
| |
| /* |
| * given auth method name, if configurable options permit this method fill |
| * in auth_ident field and return true, otherwise return false. |
| */ |
| static int |
| authmethod_is_enabled(Authmethod *method) |
| { |
| if (method == NULL) |
| return 0; |
| /* return false if options indicate this method is disabled */ |
| if (method->enabled == NULL || *method->enabled == 0) |
| return 0; |
| /* return false if batch mode is enabled but method needs interactive mode */ |
| if (method->batch_flag != NULL && *method->batch_flag != 0) |
| return 0; |
| return 1; |
| } |
| |
| static Authmethod * |
| authmethod_lookup(const char *name) |
| { |
| Authmethod *method = NULL; |
| if (name != NULL) |
| for (method = authmethods; method->name != NULL; method++) |
| if (strcmp(name, method->name) == 0) |
| return method; |
| debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); |
| return NULL; |
| } |
| |
| /* XXX internal state */ |
| static Authmethod *current = NULL; |
| static char *supported = NULL; |
| static char *preferred = NULL; |
| |
| /* |
| * Given the authentication method list sent by the server, return the |
| * next method we should try. If the server initially sends a nil list, |
| * use a built-in default list. |
| */ |
| static Authmethod * |
| authmethod_get(char *authlist) |
| { |
| char *name = NULL; |
| u_int next; |
| |
| /* Use a suitable default if we're passed a nil list. */ |
| if (authlist == NULL || strlen(authlist) == 0) |
| authlist = options.preferred_authentications; |
| |
| if (supported == NULL || strcmp(authlist, supported) != 0) { |
| debug3("start over, passed a different list %s", authlist); |
| if (supported != NULL) |
| xfree(supported); |
| supported = xstrdup(authlist); |
| preferred = options.preferred_authentications; |
| debug3("preferred %s", preferred); |
| current = NULL; |
| } else if (current != NULL && authmethod_is_enabled(current)) |
| return current; |
| |
| for (;;) { |
| if ((name = match_list(preferred, supported, &next)) == NULL) { |
| debug("No more authentication methods to try."); |
| current = NULL; |
| return NULL; |
| } |
| preferred += next; |
| debug3("authmethod_lookup %s", name); |
| debug3("remaining preferred: %s", preferred); |
| if ((current = authmethod_lookup(name)) != NULL && |
| authmethod_is_enabled(current)) { |
| debug3("authmethod_is_enabled %s", name); |
| debug("Next authentication method: %s", name); |
| return current; |
| } |
| } |
| } |
| |
| static char * |
| authmethods_get(void) |
| { |
| Authmethod *method = NULL; |
| Buffer b; |
| char *list; |
| |
| buffer_init(&b); |
| for (method = authmethods; method->name != NULL; method++) { |
| if (authmethod_is_enabled(method)) { |
| if (buffer_len(&b) > 0) |
| buffer_append(&b, ",", 1); |
| buffer_append(&b, method->name, strlen(method->name)); |
| } |
| } |
| buffer_append(&b, "\0", 1); |
| list = xstrdup(buffer_ptr(&b)); |
| buffer_free(&b); |
| return list; |
| } |