crypto/openssh-3.8.1p1/auth-krb5.c

   1 /*
   2  *    Kerberos v5 authentication and ticket-passing routines.
   3  *
   4  * $FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp $
   5  */
   6 /*
   7  * Copyright (c) 2002 Daniel Kouril.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #include "includes.h"
  31 RCSID("$OpenBSD: auth-krb5.c,v 1.15 2003/11/21 11:57:02 djm Exp $");
  32
  33 #include "ssh.h"
  34 #include "ssh1.h"
  35 #include "packet.h"
  36 #include "xmalloc.h"
  37 #include "log.h"
  38 #include "servconf.h"
  39 #include "uidswap.h"
  40 #include "auth.h"
  41
  42 #ifdef KRB5
  43 #include <krb5.h>
  44
  45 extern ServerOptions     options;
  46
  47 static int
  48 krb5_init(void *context)
  49 {
  50         Authctxt *authctxt = (Authctxt *)context;
  51         krb5_error_code problem;
  52
  53         if (authctxt->krb5_ctx == NULL) {
  54                 problem = krb5_init_context(&authctxt->krb5_ctx);
  55                 if (problem)
  56                         return (problem);
  57 #ifdef KRB5_INIT_ETS
  58                 krb5_init_ets(authctxt->krb5_ctx);
  59 #endif
  60         }
  61         return (0);
  62 }
  63
  64 int
  65 auth_krb5_password(Authctxt *authctxt, const char *password)
  66 {
  67 #ifndef HEIMDAL
  68         krb5_creds creds;
  69         krb5_principal server;
  70         char ccname[40];
  71         int tmpfd;
  72 #endif
  73         krb5_error_code problem;
  74         krb5_ccache ccache = NULL;
  75         int len;
  76
  77         if (!authctxt->valid)
  78                 return (0);
  79
  80         temporarily_use_uid(authctxt->pw);
  81
  82         problem = krb5_init(authctxt);
  83         if (problem)
  84                 goto out;
  85
  86         problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
  87                     &authctxt->krb5_user);
  88         if (problem)
  89                 goto out;
  90
  91 #ifdef HEIMDAL
  92         problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, &ccache);
  93         if (problem)
  94                 goto out;
  95
  96         problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
  97                 authctxt->krb5_user);
  98         if (problem)
  99                 goto out;
 100
 101         restore_uid();
 102
 103         problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
 104             ccache, password, 1, NULL);
 105
 106         temporarily_use_uid(authctxt->pw);
 107
 108         if (problem)
 109                 goto out;
 110
 111         problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops,
 112             &authctxt->krb5_fwd_ccache);
 113         if (problem)
 114                 goto out;
 115
 116         problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache,
 117             authctxt->krb5_fwd_ccache);
 118         krb5_cc_destroy(authctxt->krb5_ctx, ccache);
 119         ccache = NULL;
 120         if (problem)
 121                 goto out;
 122
 123 #else
 124         problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds,
 125             authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL);
 126         if (problem)
 127                 goto out;
 128
 129         problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL,
 130             KRB5_NT_SRV_HST, &server);
 131         if (problem)
 132                 goto out;
 133
 134         restore_uid();
 135         problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server,
 136             NULL, NULL, NULL);
 137         krb5_free_principal(authctxt->krb5_ctx, server);
 138         temporarily_use_uid(authctxt->pw);
 139         if (problem)
 140                 goto out;
 141
 142         if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
 143                           authctxt->pw->pw_name)) {
 144                 problem = -1;
 145                 goto out;
 146         }
 147
 148         snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid());
 149
 150         if ((tmpfd = mkstemp(ccname+strlen("FILE:")))==-1) {
 151                 logit("mkstemp(): %.100s", strerror(errno));
 152                 problem = errno;
 153                 goto out;
 154         }
 155
 156         if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
 157                 logit("fchmod(): %.100s", strerror(errno));
 158                 close(tmpfd);
 159                 problem = errno;
 160                 goto out;
 161         }
 162         close(tmpfd);
 163
 164         problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &authctxt->krb5_fwd_ccache);
 165         if (problem)
 166                 goto out;
 167
 168         problem = krb5_cc_initialize(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
 169                                      authctxt->krb5_user);
 170         if (problem)
 171                 goto out;
 172
 173         problem= krb5_cc_store_cred(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
 174                                  &creds);
 175         if (problem)
 176                 goto out;
 177 #endif
 178
 179         authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
 180
 181         len = strlen(authctxt->krb5_ticket_file) + 6;
 182         authctxt->krb5_ccname = xmalloc(len);
 183         snprintf(authctxt->krb5_ccname, len, "FILE:%s",
 184             authctxt->krb5_ticket_file);
 185
 186  out:
 187         restore_uid();
 188
 189         if (problem) {
 190                 if (ccache)
 191                         krb5_cc_destroy(authctxt->krb5_ctx, ccache);
 192
 193                 if (authctxt->krb5_ctx != NULL && problem!=-1)
 194                         debug("Kerberos password authentication failed: %s",
 195                             krb5_get_err_text(authctxt->krb5_ctx, problem));
 196                 else
 197                         debug("Kerberos password authentication failed: %d",
 198                             problem);
 199
 200                 krb5_cleanup_proc(authctxt);
 201
 202                 if (options.kerberos_or_local_passwd)
 203                         return (-1);
 204                 else
 205                         return (0);
 206         }
 207         return (1);
 208 }
 209
 210 void
 211 krb5_cleanup_proc(Authctxt *authctxt)
 212 {
 213         debug("krb5_cleanup_proc called");
 214         if (authctxt->krb5_fwd_ccache) {
 215                 krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
 216                 authctxt->krb5_fwd_ccache = NULL;
 217         }
 218         if (authctxt->krb5_user) {
 219                 krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
 220                 authctxt->krb5_user = NULL;
 221         }
 222         if (authctxt->krb5_ctx) {
 223                 krb5_free_context(authctxt->krb5_ctx);
 224                 authctxt->krb5_ctx = NULL;
 225         }
 226 }
 227
 228 #endif /* KRB5 */