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     /* check if des key */
  55     if (cred->session.keyvalue.length != 8)
  56         return EINVAL;
  57
  58     if (local524) {
  59         Ticket t;
  60         unsigned char *buf;
  61         size_t buf_len;
  62         size_t len;
  63
  64         kvno = KAFS_RXKAD_2B_KVNO;
  65
  66         ret = decode_Ticket(cred->ticket.data, cred->ticket.length, &t, &len);
  67         if (ret)
  68             return ret;
  69         if (t.tkt_vno != 5)
  70             return -1;
  71
  72         ASN1_MALLOC_ENCODE(EncryptedData, buf, buf_len, &t.enc_part,
  73                            &len, ret);
  74         free_Ticket(&t);
  75         if (ret)
  76             return ret;
  77         if(buf_len != len) {
  78             free(buf);
  79             return KRB5KRB_ERR_GENERIC;
  80         }
  81
  82         kt->ticket = buf;
  83         kt->ticket_len = buf_len;
  84
  85     } else {
  86         kvno = KAFS_RXKAD_K5_KVNO;
  87         kt->ticket = malloc(cred->ticket.length);
  88         if (kt->ticket == NULL)
  89             return ENOMEM;
  90         kt->ticket_len = cred->ticket.length;
  91         memcpy(kt->ticket, cred->ticket.data, kt->ticket_len);
  92
  93         ret = 0;
  94     }
  95
  96
  97     /*
  98      * Build a struct ClearToken
  99      */
 100
 101     kt->ct.AuthHandle = kvno;
 102     memcpy(kt->ct.HandShakeKey, cred->session.keyvalue.data, 8);
 103     kt->ct.ViceId = uid;
 104     kt->ct.BeginTimestamp = cred->times.starttime;
 105     kt->ct.EndTimestamp = cred->times.endtime;
 106
 107     _kafs_fixup_viceid(&kt->ct, uid);
 108
 109     return 0;
 110 }
 111
 112 static krb5_error_code
 113 v5_convert(krb5_context context, krb5_ccache id,
 114            krb5_creds *cred, uid_t uid,
 115            const char *cell,
 116            struct kafs_token *kt)
 117 {
 118     krb5_error_code ret;
 119     char *c, *val;
 120
 121     c = strdup(cell);
 122     if (c == NULL)
 123         return ENOMEM;
 124     _kafs_foldup(c, c);
 125     krb5_appdefault_string (context, "libkafs",
 126                             c,
 127                             "afs-use-524", "2b", &val);
 128     free(c);
 129
 130     if (strcasecmp(val, "local") == 0 ||
 131         strcasecmp(val, "2b") == 0)
 132         ret = v5_to_kt(cred, uid, kt, 1);
 133     else
 134         ret = v5_to_kt(cred, uid, kt, 0);
 135
 136     free(val);
 137     return ret;
 138 }
 139
 140
 141 /*
 142  *
 143  */
 144
 145 static int
 146 get_cred(struct kafs_data *data, const char *name, const char *inst,
 147          const char *realm, uid_t uid, struct kafs_token *kt)
 148 {
 149     krb5_error_code ret;
 150     krb5_creds in_creds, *out_creds;
 151     struct krb5_kafs_data *d = data->data;
 152     int invalid;
 153
 154     memset(&in_creds, 0, sizeof(in_creds));
 155
 156     ret = krb5_make_principal(d->context, &in_creds.server,
 157                               realm, name, inst, NULL);
 158     if(ret)
 159         return ret;
 160     ret = krb5_cc_get_principal(d->context, d->id, &in_creds.client);
 161     if(ret){
 162         krb5_free_principal(d->context, in_creds.server);
 163         return ret;
 164     }
 165
 166     in_creds.session.keytype = ETYPE_DES_CBC_CRC;
 167
 168     /* check if des is disable, and in that case enable it for afs */
 169     invalid = krb5_enctype_valid(d->context, in_creds.session.keytype);
 170     if (invalid)
 171         krb5_enctype_enable(d->context, in_creds.session.keytype);
 172
 173     ret = krb5_get_credentials(d->context, 0, d->id, &in_creds, &out_creds);
 174     if (ret) {
 175         in_creds.session.keytype = ETYPE_DES_CBC_MD5;
 176         ret = krb5_get_credentials(d->context, 0, d->id, &in_creds, &out_creds);
 177     }
 178
 179     if (invalid)
 180         krb5_enctype_disable(d->context, in_creds.session.keytype);
 181
 182     krb5_free_principal(d->context, in_creds.server);
 183     krb5_free_principal(d->context, in_creds.client);
 184     if(ret)
 185         return ret;
 186
 187     ret = v5_convert(d->context, d->id, out_creds, uid,
 188                      (inst != NULL && inst[0] != '\0') ? inst : realm, kt);
 189     krb5_free_creds(d->context, out_creds);
 190
 191     return ret;
 192 }
 193
 194 static const char *
 195 get_error(struct kafs_data *data, int error)
 196 {
 197     struct krb5_kafs_data *d = data->data;
 198     return krb5_get_error_message(d->context, error);
 199 }
 200
 201 static void
 202 free_error(struct kafs_data *data, const char *str)
 203 {
 204     struct krb5_kafs_data *d = data->data;
 205     krb5_free_error_message(d->context, str);
 206 }
 207
 208 static krb5_error_code
 209 afslog_uid_int(struct kafs_data *data, const char *cell, const char *rh,
 210                uid_t uid, const char *homedir)
 211 {
 212     krb5_error_code ret;
 213     struct kafs_token kt;
 214     krb5_principal princ;
 215     const char *trealm; /* ticket realm */
 216     struct krb5_kafs_data *d = data->data;
 217
 218     if (cell == 0 || cell[0] == 0)
 219         return _kafs_afslog_all_local_cells (data, uid, homedir);
 220
 221     ret = krb5_cc_get_principal (d->context, d->id, &princ);
 222     if (ret)
 223         return ret;
 224
 225     trealm = krb5_principal_get_realm (d->context, princ);
 226
 227     kt.ticket = NULL;
 228     ret = _kafs_get_cred(data, cell, d->realm, trealm, uid, &kt);
 229     krb5_free_principal (d->context, princ);
 230
 231     if(ret == 0) {
 232         ret = kafs_settoken_rxkad(cell, &kt.ct, kt.ticket, kt.ticket_len);
 233         free(kt.ticket);
 234     }
 235     return ret;
 236 }
 237
 238 static char *
 239 get_realm(struct kafs_data *data, const char *host)
 240 {
 241     struct krb5_kafs_data *d = data->data;
 242     krb5_realm *realms;
 243     char *r;
 244     if(krb5_get_host_realm(d->context, host, &realms))
 245         return NULL;
 246     r = strdup(realms[0]);
 247     krb5_free_host_realm(d->context, realms);
 248     return r;
 249 }
 250
 251 krb5_error_code
 252 krb5_afslog_uid_home(krb5_context context,
 253                      krb5_ccache id,
 254                      const char *cell,
 255                      krb5_const_realm realm,
 256                      uid_t uid,
 257                      const char *homedir)
 258 {
 259     struct kafs_data kd;
 260     struct krb5_kafs_data d;
 261     krb5_error_code ret;
 262
 263     kd.name = "krb5";
 264     kd.afslog_uid = afslog_uid_int;
 265     kd.get_cred = get_cred;
 266     kd.get_realm = get_realm;
 267     kd.get_error = get_error;
 268     kd.free_error = free_error;
 269     kd.data = &d;
 270     if (context == NULL) {
 271         ret = krb5_init_context(&d.context);
 272         if (ret)
 273             return ret;
 274     } else
 275         d.context = context;
 276     if (id == NULL) {
 277         ret = krb5_cc_default(d.context, &d.id);
 278         if (ret)
 279             goto out;
 280     } else
 281         d.id = id;
 282     d.realm = realm;
 283     ret = afslog_uid_int(&kd, cell, 0, uid, homedir);
 284     if (id == NULL)
 285         krb5_cc_close(context, d.id);
 286  out:
 287     if (context == NULL)
 288         krb5_free_context(d.context);
 289     return ret;
 290 }
 291
 292 krb5_error_code
 293 krb5_afslog_uid(krb5_context context,
 294                 krb5_ccache id,
 295                 const char *cell,
 296                 krb5_const_realm realm,
 297                 uid_t uid)
 298 {
 299     return krb5_afslog_uid_home (context, id, cell, realm, uid, NULL);
 300 }
 301
 302 krb5_error_code
 303 krb5_afslog(krb5_context context,
 304             krb5_ccache id,
 305             const char *cell,
 306             krb5_const_realm realm)
 307 {
 308     return krb5_afslog_uid (context, id, cell, realm, getuid());
 309 }
 310
 311 krb5_error_code
 312 krb5_afslog_home(krb5_context context,
 313                  krb5_ccache id,
 314                  const char *cell,
 315                  krb5_const_realm realm,
 316                  const char *homedir)
 317 {
 318     return krb5_afslog_uid_home (context, id, cell, realm, getuid(), homedir);
 319 }
 320
 321 /*
 322  *
 323  */
 324
 325 krb5_error_code
 326 krb5_realm_of_cell(const char *cell, char **realm)
 327 {
 328     struct kafs_data kd;
 329
 330     kd.name = "krb5";
 331     kd.get_realm = get_realm;
 332     kd.get_error = get_error;
 333     kd.free_error = free_error;
 334     return _kafs_realm_of_cell(&kd, cell, realm);
 335 }
 336
 337 /*
 338  *
 339  */
 340
 341 int
 342 kafs_settoken5(krb5_context context, const char *cell, uid_t uid,
 343                krb5_creds *cred)
 344 {
 345     struct kafs_token kt;
 346     int ret;
 347
 348     ret = v5_convert(context, NULL, cred, uid, cell, &kt);
 349     if (ret)
 350         return ret;
 351
 352     ret = kafs_settoken_rxkad(cell, &kt.ct, kt.ticket, kt.ticket_len);
 353
 354     free(kt.ticket);
 355
 356     return ret;
 357 }