lib/kafs/afskrb5.c

   1 /*
   2  * Copyright (c) 1995-2003 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "kafs_locl.h"
  35
  36 struct krb5_kafs_data {
  37     krb5_context context;
  38     krb5_ccache id;
  39     krb5_const_realm realm;
  40 };
  41
  42 enum {
  43     KAFS_RXKAD_2B_KVNO = 213,
  44     KAFS_RXKAD_K5_KVNO = 256
  45 };
  46
  47 static int
  48 v5_to_kt(krb5_creds *cred, uid_t uid, struct kafs_token *kt, int local524)
  49 {
  50     int kvno, ret;
  51
  52     kt->ticket = NULL;
  53
  54     if (local524) {
  55         Ticket t;
  56         unsigned char *buf;
  57         size_t buf_len;
  58         size_t len;
  59
  60         kvno = KAFS_RXKAD_2B_KVNO;
  61
  62         ret = decode_Ticket(cred->ticket.data, cred->ticket.length, &t, &len);
  63         if (ret)
  64             return ret;
  65         if (t.tkt_vno != 5)
  66             return -1;
  67
  68         ASN1_MALLOC_ENCODE(EncryptedData, buf, buf_len, &t.enc_part,
  69                            &len, ret);
  70         free_Ticket(&t);
  71         if (ret)
  72             return ret;
  73         if(buf_len != len) {
  74             free(buf);
  75             return KRB5KRB_ERR_GENERIC;
  76         }
  77
  78         kt->ticket = buf;
  79         kt->ticket_len = buf_len;
  80
  81     } else {
  82         kvno = KAFS_RXKAD_K5_KVNO;
  83         kt->ticket = malloc(cred->ticket.length);
  84         if (kt->ticket == NULL)
  85             return ENOMEM;
  86         kt->ticket_len = cred->ticket.length;
  87         memcpy(kt->ticket, cred->ticket.data, kt->ticket_len);
  88
  89         ret = 0;
  90     }
  91
  92
  93     /*
  94      * Build a struct ClearToken
  95      */
  96
  97     ret = _kafs_derive_des_key(cred->session.keytype,
  98                                cred->session.keyvalue.data,
  99                                cred->session.keyvalue.length,
 100                                kt->ct.HandShakeKey);
 101     if (ret) {
 102         free(kt->ticket);
 103         kt->ticket = NULL;
 104         return ret;
 105     }
 106     kt->ct.AuthHandle = kvno;
 107     kt->ct.ViceId = uid;
 108     kt->ct.BeginTimestamp = cred->times.starttime;
 109     kt->ct.EndTimestamp = cred->times.endtime;
 110
 111     _kafs_fixup_viceid(&kt->ct, uid);
 112
 113     return 0;
 114 }
 115
 116 static krb5_error_code
 117 v5_convert(krb5_context context, krb5_ccache id,
 118            krb5_creds *cred, uid_t uid,
 119            const char *cell,
 120            struct kafs_token *kt)
 121 {
 122     krb5_error_code ret;
 123     char *c, *val;
 124
 125     c = strdup(cell);
 126     if (c == NULL)
 127         return ENOMEM;
 128     _kafs_foldup(c, c);
 129     krb5_appdefault_string (context, "libkafs",
 130                             c,
 131                             "afs-use-524", "2b", &val);
 132     free(c);
 133
 134     if (strcasecmp(val, "local") == 0 ||
 135         strcasecmp(val, "2b") == 0)
 136         ret = v5_to_kt(cred, uid, kt, 1);
 137     else
 138         ret = v5_to_kt(cred, uid, kt, 0);
 139
 140     free(val);
 141     return ret;
 142 }
 143
 144
 145 /*
 146  *
 147  */
 148
 149 static int
 150 get_cred(struct kafs_data *data, const char *name, const char *inst,
 151          const char *realm, uid_t uid, struct kafs_token *kt)
 152 {
 153     krb5_error_code ret;
 154     krb5_creds in_creds, *out_creds;
 155     struct krb5_kafs_data *d = data->data;
 156     int invalid;
 157
 158     memset(&in_creds, 0, sizeof(in_creds));
 159
 160     ret = krb5_make_principal(d->context, &in_creds.server,
 161                               realm, name, inst, NULL);
 162     if(ret)
 163         return ret;
 164     ret = krb5_cc_get_principal(d->context, d->id, &in_creds.client);
 165     if(ret){
 166         krb5_free_principal(d->context, in_creds.server);
 167         return ret;
 168     }
 169
 170     /* check if des is disable, and in that case enable it for afs */
 171     invalid = krb5_enctype_valid(d->context, ETYPE_DES_CBC_CRC);
 172     if (invalid)
 173         krb5_enctype_enable(d->context, ETYPE_DES_CBC_CRC);
 174
 175     ret = krb5_get_credentials(d->context, 0, d->id, &in_creds, &out_creds);
 176
 177     if (invalid)
 178         krb5_enctype_disable(d->context, ETYPE_DES_CBC_CRC);
 179
 180     krb5_free_principal(d->context, in_creds.server);
 181     krb5_free_principal(d->context, in_creds.client);
 182     if(ret)
 183         return ret;
 184
 185     ret = v5_convert(d->context, d->id, out_creds, uid,
 186                      (inst != NULL && inst[0] != '\0') ? inst : realm, kt);
 187     krb5_free_creds(d->context, out_creds);
 188
 189     return ret;
 190 }
 191
 192 static const char *
 193 get_error(struct kafs_data *data, int error)
 194 {
 195     struct krb5_kafs_data *d = data->data;
 196     return krb5_get_error_message(d->context, error);
 197 }
 198
 199 static void
 200 free_error(struct kafs_data *data, const char *str)
 201 {
 202     struct krb5_kafs_data *d = data->data;
 203     krb5_free_error_message(d->context, str);
 204 }
 205
 206 static krb5_error_code
 207 afslog_uid_int(struct kafs_data *data, const char *cell, const char *rh,
 208                uid_t uid, const char *homedir)
 209 {
 210     krb5_error_code ret;
 211     struct kafs_token kt;
 212     krb5_principal princ;
 213     const char *trealm; /* ticket realm */
 214     struct krb5_kafs_data *d = data->data;
 215
 216     if (cell == 0 || cell[0] == 0)
 217         return _kafs_afslog_all_local_cells (data, uid, homedir);
 218
 219     ret = krb5_cc_get_principal (d->context, d->id, &princ);
 220     if (ret)
 221         return ret;
 222
 223     trealm = krb5_principal_get_realm (d->context, princ);
 224
 225     kt.ticket = NULL;
 226     ret = _kafs_get_cred(data, cell, d->realm, trealm, uid, &kt);
 227     krb5_free_principal (d->context, princ);
 228
 229     if(ret == 0) {
 230         ret = kafs_settoken_rxkad(cell, &kt.ct, kt.ticket, kt.ticket_len);
 231         free(kt.ticket);
 232     }
 233     return ret;
 234 }
 235
 236 static char *
 237 get_realm(struct kafs_data *data, const char *host)
 238 {
 239     struct krb5_kafs_data *d = data->data;
 240     krb5_realm *realms;
 241     char *r;
 242     if(krb5_get_host_realm(d->context, host, &realms))
 243         return NULL;
 244     r = strdup(realms[0]);
 245     krb5_free_host_realm(d->context, realms);
 246     return r;
 247 }
 248
 249 krb5_error_code
 250 krb5_afslog_uid_home(krb5_context context,
 251                      krb5_ccache id,
 252                      const char *cell,
 253                      krb5_const_realm realm,
 254                      uid_t uid,
 255                      const char *homedir)
 256 {
 257     struct kafs_data kd;
 258     struct krb5_kafs_data d;
 259     krb5_error_code ret;
 260
 261     kd.name = "krb5";
 262     kd.afslog_uid = afslog_uid_int;
 263     kd.get_cred = get_cred;
 264     kd.get_realm = get_realm;
 265     kd.get_error = get_error;
 266     kd.free_error = free_error;
 267     kd.data = &d;
 268     if (context == NULL) {
 269         ret = krb5_init_context(&d.context);
 270         if (ret)
 271             return ret;
 272     } else
 273         d.context = context;
 274     if (id == NULL) {
 275         ret = krb5_cc_default(d.context, &d.id);
 276         if (ret)
 277             goto out;
 278     } else
 279         d.id = id;
 280     d.realm = realm;
 281     ret = afslog_uid_int(&kd, cell, 0, uid, homedir);
 282     if (id == NULL)
 283         krb5_cc_close(context, d.id);
 284  out:
 285     if (context == NULL)
 286         krb5_free_context(d.context);
 287     return ret;
 288 }
 289
 290 krb5_error_code
 291 krb5_afslog_uid(krb5_context context,
 292                 krb5_ccache id,
 293                 const char *cell,
 294                 krb5_const_realm realm,
 295                 uid_t uid)
 296 {
 297     return krb5_afslog_uid_home (context, id, cell, realm, uid, NULL);
 298 }
 299
 300 krb5_error_code
 301 krb5_afslog(krb5_context context,
 302             krb5_ccache id,
 303             const char *cell,
 304             krb5_const_realm realm)
 305 {
 306     return krb5_afslog_uid (context, id, cell, realm, getuid());
 307 }
 308
 309 krb5_error_code
 310 krb5_afslog_home(krb5_context context,
 311                  krb5_ccache id,
 312                  const char *cell,
 313                  krb5_const_realm realm,
 314                  const char *homedir)
 315 {
 316     return krb5_afslog_uid_home (context, id, cell, realm, getuid(), homedir);
 317 }
 318
 319 /*
 320  *
 321  */
 322
 323 krb5_error_code
 324 krb5_realm_of_cell(const char *cell, char **realm)
 325 {
 326     struct kafs_data kd;
 327
 328     kd.name = "krb5";
 329     kd.get_realm = get_realm;
 330     kd.get_error = get_error;
 331     kd.free_error = free_error;
 332     return _kafs_realm_of_cell(&kd, cell, realm);
 333 }
 334
 335 /*
 336  *
 337  */
 338
 339 int
 340 kafs_settoken5(krb5_context context, const char *cell, uid_t uid,
 341                krb5_creds *cred)
 342 {
 343     struct kafs_token kt;
 344     int ret;
 345
 346     ret = v5_convert(context, NULL, cred, uid, cell, &kt);
 347     if (ret)
 348         return ret;
 349
 350     ret = kafs_settoken_rxkad(cell, &kt.ct, kt.ticket, kt.ticket_len);
 351
 352     free(kt.ticket);
 353
 354     return ret;
 355 }