usr/src/lib/smbsrv/libsmbns/common/smbns_krb.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
  25  */
  26 /*
  27  * Copyright 1990 by the Massachusetts Institute of Technology.
  28  * All Rights Reserved.
  29  *
  30  * Export of this software from the United States of America may
  31  *   require a specific license from the United States Government.
  32  *   It is the responsibility of any person or organization contemplating
  33  *   export to obtain such a license before exporting.
  34  *
  35  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
  36  * distribute this software and its documentation for any purpose and
  37  * without fee is hereby granted, provided that the above copyright
  38  * notice appear in all copies and that both that copyright notice and
  39  * this permission notice appear in supporting documentation, and that
  40  * the name of M.I.T. not be used in advertising or publicity pertaining
  41  * to distribution of the software without specific, written prior
  42  * permission.  Furthermore if you modify this software you must label
  43  * your software as modified software and not distribute it in such a
  44  * fashion that it might be confused with the original M.I.T. software.
  45  * M.I.T. makes no representations about the suitability of
  46  * this software for any purpose.  It is provided "as is" without express
  47  * or implied warranty.
  48  *
  49  *
  50  * Initialize a credentials cache.
  51  */
  52 #include <kerberosv5/krb5.h>
  53 #include <kerberosv5/com_err.h>
  54 #include <assert.h>
  55 #include <stdio.h>
  56 #include <syslog.h>
  57 #include <errno.h>
  58
  59 #include <smbsrv/libsmbns.h>
  60 #include <smbns_krb.h>
  61
  62 int
  63 smb_kinit(char *domain_name, char *principal_name, char *principal_passwd)
  64 {
  65         char default_realm[MAXHOSTNAMELEN];
  66         krb5_context ctx = NULL;
  67         krb5_ccache cc = NULL;
  68         krb5_principal me = NULL;
  69         krb5_creds my_creds;
  70         krb5_error_code code;
  71         const char *errmsg = NULL;
  72         const char *doing = NULL;
  73         smb_ads_status_t err;
  74
  75         assert(principal_name != NULL);
  76         assert(principal_passwd != NULL);
  77
  78         (void) memset(&my_creds, 0, sizeof (my_creds));
  79
  80         /*
  81          * From this point on, we can goto cleanup because the key variables
  82          * are initialized.
  83          */
  84
  85         code = krb5_init_context(&ctx);
  86         if (code) {
  87                 err = SMB_ADS_KRB5_INIT_CTX;
  88                 doing = "smbns_krb: initializing context";
  89                 goto cleanup;
  90         }
  91
  92         /*
  93          * In case krb5.conf is not configured, set the default realm.
  94          */
  95         (void) strlcpy(default_realm, domain_name, sizeof (default_realm));
  96         (void) smb_strupr(default_realm);
  97         (void) krb5_set_default_realm(ctx, default_realm);
  98
  99         code = krb5_cc_default(ctx, &cc);
 100         if (code != 0) {
 101                 err = SMB_ADS_KRB5_CC_DEFAULT;
 102                 doing = "smbns_krb: resolve default credentials cache";
 103                 goto cleanup;
 104         }
 105
 106         /* Use specified name */
 107         code = krb5_parse_name(ctx, principal_name, &me);
 108         if (code != 0) {
 109                 err = SMB_ADS_KRB5_PARSE_PRINCIPAL;
 110                 doing = "smbns_krb: parsing principal name";
 111                 goto cleanup;
 112         }
 113
 114         code = krb5_get_init_creds_password(ctx, &my_creds, me,
 115             principal_passwd, NULL, 0, (krb5_deltat)0,
 116             NULL, NULL);
 117         if (code != 0) {
 118                 err = SMB_ADS_KRB5_GET_INIT_CREDS_PW;
 119                 doing = "smbns_krb: getting initial credentials";
 120
 121                 if (code == KRB5KRB_AP_ERR_BAD_INTEGRITY) {
 122                         errmsg = "smbns_krb: Password incorrect";
 123                 }
 124
 125                 goto cleanup;
 126         }
 127
 128         code = krb5_cc_initialize(ctx, cc, me);
 129         if (code != 0) {
 130                 err = SMB_ADS_KRB5_CC_INITIALIZE;
 131                 doing = "smbns_krb: initializing cache";
 132                 goto cleanup;
 133         }
 134
 135         code = krb5_cc_store_cred(ctx, cc, &my_creds);
 136         if (code != 0) {
 137                 err = SMB_ADS_KRB5_CC_STORE_CRED;
 138                 doing = "smbns_krb: storing credentials";
 139                 goto cleanup;
 140         }
 141
 142         /* SUCCESS! */
 143         err = SMB_ADS_SUCCESS;
 144
 145 cleanup:
 146         if (code != 0) {
 147                 if (errmsg == NULL)
 148                         smb_krb5_log_errmsg(ctx, doing, code);
 149                 else
 150                         syslog(LOG_ERR, "%s (%s)", doing, errmsg);
 151         }
 152
 153         if (my_creds.client == me) {
 154                 my_creds.client = NULL;
 155         }
 156         krb5_free_cred_contents(ctx, &my_creds);
 157
 158         if (me)
 159                 krb5_free_principal(ctx, me);
 160         if (cc)
 161                 (void) krb5_cc_close(ctx, cc);
 162         if (ctx)
 163                 krb5_free_context(ctx);
 164
 165         return (err);
 166 }
 167
 168 /*
 169  * Invoke krb5_get_error_message() to generate a richer error message.
 170  */
 171 void
 172 smb_krb5_log_errmsg(krb5_context ctx, const char *prefix, krb5_error_code code)
 173 {
 174         const char *msg;
 175
 176         msg = krb5_get_error_message(ctx, code);
 177         syslog(LOG_ERR, "%s (%s)", prefix, msg);
 178         krb5_free_error_message(ctx, msg);
 179 }
 180
 181 /*
 182  * smb_ccache_init
 183  *
 184  * Creates the directory where the Kerberos ccache file is located
 185  * and set KRB5CCNAME in the environment.
 186  *
 187  * Returns 0 upon succcess.  Otherwise, returns
 188  * -1 if it fails to create the specified directory fails.
 189  * -2 if it fails to set the KRB5CCNAME environment variable.
 190  */
 191 int
 192 smb_ccache_init(char *dir, char *filename)
 193 {
 194         static char buf[MAXPATHLEN];
 195
 196         if ((mkdir(dir, 0700) < 0) && (errno != EEXIST))
 197                 return (-1);
 198
 199         (void) snprintf(buf, MAXPATHLEN, "KRB5CCNAME=%s/%s", dir, filename);
 200         if (putenv(buf) != 0)
 201                 return (-2);
 202         return (0);
 203 }
 204
 205 void
 206 smb_ccache_remove(char *path)
 207 {
 208         if ((remove(path) < 0) && (errno != ENOENT))
 209                 syslog(LOG_ERR, "smbns_krb: failed to remove ccache (%s)",
 210                     path);
 211 }