| /* |
| * Kerberos v5 authentication and ticket-passing routines. |
| * |
| * $FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp $ |
| */ |
| /* |
| * Copyright (c) 2002 Daniel Kouril. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "includes.h" |
| RCSID("$OpenBSD: auth-krb5.c,v 1.11 2003/07/16 15:02:06 markus Exp $"); |
| |
| #include "ssh.h" |
| #include "ssh1.h" |
| #include "packet.h" |
| #include "xmalloc.h" |
| #include "log.h" |
| #include "servconf.h" |
| #include "uidswap.h" |
| #include "auth.h" |
| |
| #ifdef KRB5 |
| |
| #include <krb5.h> |
| #ifndef HEIMDAL |
| #define krb5_get_err_text(context,code) error_message(code) |
| #endif /* !HEIMDAL */ |
| |
| extern ServerOptions options; |
| |
| static int |
| krb5_init(void *context) |
| { |
| Authctxt *authctxt = (Authctxt *)context; |
| krb5_error_code problem; |
| static int cleanup_registered = 0; |
| |
| if (authctxt->krb5_ctx == NULL) { |
| problem = krb5_init_context(&authctxt->krb5_ctx); |
| if (problem) |
| return (problem); |
| krb5_init_ets(authctxt->krb5_ctx); |
| } |
| if (!cleanup_registered) { |
| fatal_add_cleanup(krb5_cleanup_proc, authctxt); |
| cleanup_registered = 1; |
| } |
| return (0); |
| } |
| |
| /* |
| * Try krb5 authentication. server_user is passed for logging purposes |
| * only, in auth is received ticket, in client is returned principal |
| * from the ticket |
| */ |
| int |
| auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *reply) |
| { |
| krb5_error_code problem; |
| krb5_principal server; |
| krb5_ticket *ticket; |
| int fd, ret; |
| |
| ret = 0; |
| server = NULL; |
| ticket = NULL; |
| reply->length = 0; |
| |
| problem = krb5_init(authctxt); |
| if (problem) |
| goto err; |
| |
| problem = krb5_auth_con_init(authctxt->krb5_ctx, |
| &authctxt->krb5_auth_ctx); |
| if (problem) |
| goto err; |
| |
| fd = packet_get_connection_in(); |
| #ifdef HEIMDAL |
| problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx, |
| authctxt->krb5_auth_ctx, &fd); |
| #else |
| problem = krb5_auth_con_genaddrs(authctxt->krb5_ctx, |
| authctxt->krb5_auth_ctx,fd, |
| KRB5_AUTH_CONTEXT_GENERATE_REMOTE_FULL_ADDR | |
| KRB5_AUTH_CONTEXT_GENERATE_LOCAL_FULL_ADDR); |
| #endif |
| if (problem) |
| goto err; |
| |
| problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL, |
| KRB5_NT_SRV_HST, &server); |
| if (problem) |
| goto err; |
| |
| problem = krb5_rd_req(authctxt->krb5_ctx, &authctxt->krb5_auth_ctx, |
| auth, server, NULL, NULL, &ticket); |
| if (problem) |
| goto err; |
| |
| #ifdef HEIMDAL |
| problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client, |
| &authctxt->krb5_user); |
| #else |
| problem = krb5_copy_principal(authctxt->krb5_ctx, |
| ticket->enc_part2->client, |
| &authctxt->krb5_user); |
| #endif |
| if (problem) |
| goto err; |
| |
| /* if client wants mutual auth */ |
| problem = krb5_mk_rep(authctxt->krb5_ctx, authctxt->krb5_auth_ctx, |
| reply); |
| if (problem) |
| goto err; |
| |
| /* Check .k5login authorization now. */ |
| if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, |
| authctxt->pw->pw_name)) |
| goto err; |
| |
| if (client) |
| krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user, |
| client); |
| |
| ret = 1; |
| err: |
| if (server) |
| krb5_free_principal(authctxt->krb5_ctx, server); |
| if (ticket) |
| krb5_free_ticket(authctxt->krb5_ctx, ticket); |
| if (!ret && reply->length) { |
| xfree(reply->data); |
| memset(reply, 0, sizeof(*reply)); |
| } |
| |
| if (problem) { |
| if (authctxt->krb5_ctx != NULL) |
| debug("Kerberos v5 authentication failed: %s", |
| krb5_get_err_text(authctxt->krb5_ctx, problem)); |
| else |
| debug("Kerberos v5 authentication failed: %d", |
| problem); |
| } |
| |
| return (ret); |
| } |
| |
| int |
| auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt) |
| { |
| krb5_error_code problem; |
| krb5_ccache ccache = NULL; |
| char *pname; |
| krb5_creds **creds; |
| |
| if (authctxt->pw == NULL || authctxt->krb5_user == NULL) |
| return (0); |
| |
| temporarily_use_uid(authctxt->pw); |
| |
| #ifdef HEIMDAL |
| problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache); |
| #else |
| { |
| char ccname[40]; |
| int tmpfd; |
| |
| snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid()); |
| |
| if ((tmpfd = mkstemp(ccname+strlen("FILE:")))==-1) { |
| logit("mkstemp(): %.100s", strerror(errno)); |
| problem = errno; |
| goto fail; |
| } |
| if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) { |
| logit("fchmod(): %.100s", strerror(errno)); |
| close(tmpfd); |
| problem = errno; |
| goto fail; |
| } |
| close(tmpfd); |
| problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &ccache); |
| } |
| #endif |
| if (problem) |
| goto fail; |
| |
| problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache, |
| authctxt->krb5_user); |
| if (problem) |
| goto fail; |
| |
| #ifdef HEIMDAL |
| problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx, |
| ccache, tgt); |
| if (problem) |
| goto fail; |
| #else |
| problem = krb5_rd_cred(authctxt->krb5_ctx, authctxt->krb5_auth_ctx, |
| tgt, &creds, NULL); |
| if (problem) |
| goto fail; |
| problem = krb5_cc_store_cred(authctxt->krb5_ctx, ccache, *creds); |
| if (problem) |
| goto fail; |
| #endif |
| |
| authctxt->krb5_fwd_ccache = ccache; |
| ccache = NULL; |
| |
| authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); |
| |
| problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user, |
| &pname); |
| if (problem) |
| goto fail; |
| |
| debug("Kerberos v5 TGT accepted (%s)", pname); |
| |
| restore_uid(); |
| |
| return (1); |
| |
| fail: |
| if (problem) |
| debug("Kerberos v5 TGT passing failed: %s", |
| krb5_get_err_text(authctxt->krb5_ctx, problem)); |
| if (ccache) |
| krb5_cc_destroy(authctxt->krb5_ctx, ccache); |
| |
| restore_uid(); |
| |
| return (0); |
| } |
| |
| int |
| auth_krb5_password(Authctxt *authctxt, const char *password) |
| { |
| #ifndef HEIMDAL |
| krb5_creds creds; |
| krb5_principal server; |
| char ccname[40]; |
| int tmpfd; |
| #endif |
| krb5_error_code problem; |
| krb5_ccache ccache = NULL; |
| |
| if (authctxt->pw == NULL) |
| return (0); |
| |
| temporarily_use_uid(authctxt->pw); |
| |
| problem = krb5_init(authctxt); |
| if (problem) |
| goto out; |
| |
| problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name, |
| &authctxt->krb5_user); |
| if (problem) |
| goto out; |
| |
| #ifdef HEIMDAL |
| problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, &ccache); |
| if (problem) |
| goto out; |
| |
| problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache, |
| authctxt->krb5_user); |
| if (problem) |
| goto out; |
| |
| restore_uid(); |
| |
| problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user, |
| ccache, password, 1, NULL); |
| |
| temporarily_use_uid(authctxt->pw); |
| |
| if (problem) |
| goto out; |
| problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, |
| &authctxt->krb5_fwd_ccache); |
| if (problem) |
| goto out; |
| |
| problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache, |
| authctxt->krb5_fwd_ccache); |
| krb5_cc_destroy(authctxt->krb5_ctx, ccache); |
| ccache = NULL; |
| if (problem) |
| goto out; |
| |
| #else |
| problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds, |
| authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL); |
| if (problem) |
| goto out; |
| |
| problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL, |
| KRB5_NT_SRV_HST, &server); |
| if (problem) |
| goto out; |
| |
| restore_uid(); |
| problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server, |
| NULL, NULL, NULL); |
| krb5_free_principal(authctxt->krb5_ctx, server); |
| temporarily_use_uid(authctxt->pw); |
| if (problem) |
| goto out; |
| |
| if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, |
| authctxt->pw->pw_name)) { |
| problem = -1; |
| goto out; |
| } |
| |
| snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid()); |
| |
| if ((tmpfd = mkstemp(ccname+strlen("FILE:")))==-1) { |
| logit("mkstemp(): %.100s", strerror(errno)); |
| problem = errno; |
| goto out; |
| } |
| |
| if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) { |
| logit("fchmod(): %.100s", strerror(errno)); |
| close(tmpfd); |
| problem = errno; |
| goto out; |
| } |
| close(tmpfd); |
| |
| problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &authctxt->krb5_fwd_ccache); |
| if (problem) |
| goto out; |
| |
| problem = krb5_cc_initialize(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache, |
| authctxt->krb5_user); |
| if (problem) |
| goto out; |
| |
| problem= krb5_cc_store_cred(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache, |
| &creds); |
| if (problem) |
| goto out; |
| #endif |
| |
| authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); |
| |
| out: |
| restore_uid(); |
| |
| if (problem) { |
| if (ccache) |
| krb5_cc_destroy(authctxt->krb5_ctx, ccache); |
| |
| if (authctxt->krb5_ctx != NULL && problem!=-1) |
| debug("Kerberos password authentication failed: %s", |
| krb5_get_err_text(authctxt->krb5_ctx, problem)); |
| else |
| debug("Kerberos password authentication failed: %d", |
| problem); |
| |
| krb5_cleanup_proc(authctxt); |
| |
| if (options.kerberos_or_local_passwd) |
| return (-1); |
| else |
| return (0); |
| } |
| return (1); |
| } |
| |
| void |
| krb5_cleanup_proc(void *context) |
| { |
| Authctxt *authctxt = (Authctxt *)context; |
| |
| debug("krb5_cleanup_proc called"); |
| if (authctxt->krb5_fwd_ccache) { |
| krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); |
| authctxt->krb5_fwd_ccache = NULL; |
| } |
| if (authctxt->krb5_user) { |
| krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user); |
| authctxt->krb5_user = NULL; |
| } |
| if (authctxt->krb5_auth_ctx) { |
| krb5_auth_con_free(authctxt->krb5_ctx, |
| authctxt->krb5_auth_ctx); |
| authctxt->krb5_auth_ctx = NULL; |
| } |
| if (authctxt->krb5_ctx) { |
| krb5_free_context(authctxt->krb5_ctx); |
| authctxt->krb5_ctx = NULL; |
| } |
| } |
| |
| #endif /* KRB5 */ |