| /* $OpenBSD: gss-serv-krb5.c,v 1.2 2003/11/21 11:57:03 djm Exp $ */ |
| |
| /* |
| * Copyright (c) 2001-2003 Simon Wilkinson. 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" |
| |
| #ifdef GSSAPI |
| #ifdef KRB5 |
| |
| #include "auth.h" |
| #include "xmalloc.h" |
| #include "log.h" |
| #include "servconf.h" |
| |
| #include "ssh-gss.h" |
| |
| extern ServerOptions options; |
| |
| #ifdef HEIMDAL |
| # include <krb5.h> |
| #else |
| # ifdef HAVE_GSSAPI_KRB5 |
| # include <gssapi_krb5.h> |
| # elif HAVE_GSSAPI_GSSAPI_KRB5 |
| # include <gssapi/gssapi_krb5.h> |
| # endif |
| #endif |
| |
| static krb5_context krb_context = NULL; |
| |
| /* Initialise the krb5 library, for the stuff that GSSAPI won't do */ |
| |
| static int |
| ssh_gssapi_krb5_init() |
| { |
| krb5_error_code problem; |
| |
| if (krb_context != NULL) |
| return 1; |
| |
| problem = krb5_init_context(&krb_context); |
| if (problem) { |
| logit("Cannot initialize krb5 context"); |
| return 0; |
| } |
| krb5_init_ets(krb_context); |
| |
| return 1; |
| } |
| |
| /* Check if this user is OK to login. This only works with krb5 - other |
| * GSSAPI mechanisms will need their own. |
| * Returns true if the user is OK to log in, otherwise returns 0 |
| */ |
| |
| static int |
| ssh_gssapi_krb5_userok(ssh_gssapi_client *client, char *name) |
| { |
| krb5_principal princ; |
| int retval; |
| |
| if (ssh_gssapi_krb5_init() == 0) |
| return 0; |
| |
| if ((retval = krb5_parse_name(krb_context, client->exportedname.value, |
| &princ))) { |
| logit("krb5_parse_name(): %.100s", |
| krb5_get_err_text(krb_context, retval)); |
| return 0; |
| } |
| if (krb5_kuserok(krb_context, princ, name)) { |
| retval = 1; |
| logit("Authorized to %s, krb5 principal %s (krb5_kuserok)", |
| name, (char *)client->displayname.value); |
| } else |
| retval = 0; |
| |
| krb5_free_principal(krb_context, princ); |
| return retval; |
| } |
| |
| |
| /* This writes out any forwarded credentials from the structure populated |
| * during userauth. Called after we have setuid to the user */ |
| |
| static void |
| ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client) |
| { |
| krb5_ccache ccache; |
| krb5_error_code problem; |
| krb5_principal princ; |
| OM_uint32 maj_status, min_status; |
| int len; |
| |
| if (client->creds == NULL) { |
| debug("No credentials stored"); |
| return; |
| } |
| |
| if (ssh_gssapi_krb5_init() == 0) |
| return; |
| |
| #ifdef HEIMDAL |
| if ((problem = krb5_cc_gen_new(krb_context, &krb5_fcc_ops, &ccache))) { |
| logit("krb5_cc_gen_new(): %.100s", |
| krb5_get_err_text(krb_context, problem)); |
| return; |
| } |
| #else |
| { |
| int tmpfd; |
| char ccname[40]; |
| |
| snprintf(ccname, sizeof(ccname), |
| "FILE:/tmp/krb5cc_%d_XXXXXX", geteuid()); |
| |
| if ((tmpfd = mkstemp(ccname + strlen("FILE:"))) == -1) { |
| logit("mkstemp(): %.100s", strerror(errno)); |
| problem = errno; |
| return; |
| } |
| if (fchmod(tmpfd, S_IRUSR | S_IWUSR) == -1) { |
| logit("fchmod(): %.100s", strerror(errno)); |
| close(tmpfd); |
| problem = errno; |
| return; |
| } |
| close(tmpfd); |
| if ((problem = krb5_cc_resolve(krb_context, ccname, &ccache))) { |
| logit("krb5_cc_resolve(): %.100s", |
| krb5_get_err_text(krb_context, problem)); |
| return; |
| } |
| } |
| #endif /* #ifdef HEIMDAL */ |
| |
| if ((problem = krb5_parse_name(krb_context, |
| client->exportedname.value, &princ))) { |
| logit("krb5_parse_name(): %.100s", |
| krb5_get_err_text(krb_context, problem)); |
| krb5_cc_destroy(krb_context, ccache); |
| return; |
| } |
| |
| if ((problem = krb5_cc_initialize(krb_context, ccache, princ))) { |
| logit("krb5_cc_initialize(): %.100s", |
| krb5_get_err_text(krb_context, problem)); |
| krb5_free_principal(krb_context, princ); |
| krb5_cc_destroy(krb_context, ccache); |
| return; |
| } |
| |
| krb5_free_principal(krb_context, princ); |
| |
| if ((maj_status = gss_krb5_copy_ccache(&min_status, |
| client->creds, ccache))) { |
| logit("gss_krb5_copy_ccache() failed"); |
| krb5_cc_destroy(krb_context, ccache); |
| return; |
| } |
| |
| client->store.filename = xstrdup(krb5_cc_get_name(krb_context, ccache)); |
| client->store.envvar = "KRB5CCNAME"; |
| len = strlen(client->store.filename) + 6; |
| client->store.envval = xmalloc(len); |
| snprintf(client->store.envval, len, "FILE:%s", client->store.filename); |
| |
| #ifdef USE_PAM |
| if (options.use_pam) |
| do_pam_putenv(client->store.envvar, client->store.envval); |
| #endif |
| |
| krb5_cc_close(krb_context, ccache); |
| |
| return; |
| } |
| |
| ssh_gssapi_mech gssapi_kerberos_mech = { |
| "toWM5Slw5Ew8Mqkay+al2g==", |
| "Kerberos", |
| {9, "\x2A\x86\x48\x86\xF7\x12\x01\x02\x02"}, |
| NULL, |
| &ssh_gssapi_krb5_userok, |
| NULL, |
| &ssh_gssapi_krb5_storecreds |
| }; |
| |
| #endif /* KRB5 */ |
| |
| #endif /* GSSAPI */ |