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 RCSID("$Id$");
  37
  38 struct krb5_kafs_data {
  39     krb5_context context;
  40     krb5_ccache id;
  41     krb5_const_realm realm;
  42 };
  43
  44 enum {
  45     KAFS_RXKAD_2B_KVNO = 213,
  46     KAFS_RXKAD_K5_KVNO = 256
  47 };
  48
  49 static int
  50 v5_to_kt(krb5_creds *cred, uid_t uid, struct kafs_token *kt, int local524)
  51 {
  52     int kvno, ret;
  53
  54     kt->ticket = NULL;
  55
  56     /* check if des key */
  57     if (cred->session.keyvalue.length != 8)
  58         return EINVAL;
  59
  60     if (local524) {
  61         Ticket t;
  62         unsigned char *buf;
  63         size_t buf_len;
  64         size_t len;
  65
  66         kvno = KAFS_RXKAD_2B_KVNO;
  67
  68         ret = decode_Ticket(cred->ticket.data, cred->ticket.length, &t, &len);
  69         if (ret)
  70             return ret;
  71         if (t.tkt_vno != 5)
  72             return -1;
  73
  74         ASN1_MALLOC_ENCODE(EncryptedData, buf, buf_len, &t.enc_part,
  75                            &len, ret);
  76         free_Ticket(&t);
  77         if (ret)
  78             return ret;
  79         if(buf_len != len) {
  80             free(buf);
  81             return KRB5KRB_ERR_GENERIC;
  82         }
  83
  84         kt->ticket = buf;
  85         kt->ticket_len = buf_len;
  86
  87     } else {
  88         kvno = KAFS_RXKAD_K5_KVNO;
  89         kt->ticket = malloc(cred->ticket.length);
  90         if (kt->ticket == NULL)
  91             return ENOMEM;
  92         kt->ticket_len = cred->ticket.length;
  93         memcpy(kt->ticket, cred->ticket.data, kt->ticket_len);
  94
  95         ret = 0;
  96     }
  97
  98
  99     /*
 100      * Build a struct ClearToken
 101      */
 102
 103     kt->ct.AuthHandle = kvno;
 104     memcpy(kt->ct.HandShakeKey, cred->session.keyvalue.data, 8);
 105     kt->ct.ViceId = uid;
 106     kt->ct.BeginTimestamp = cred->times.starttime;
 107     kt->ct.EndTimestamp = cred->times.endtime;
 108
 109     _kafs_fixup_viceid(&kt->ct, uid);
 110
 111     return 0;
 112 }
 113
 114 static krb5_error_code
 115 v5_convert(krb5_context context, krb5_ccache id,
 116            krb5_creds *cred, uid_t uid,
 117            const char *cell,
 118            struct kafs_token *kt)
 119 {
 120     krb5_error_code ret;
 121     char *c, *val;
 122
 123     c = strdup(cell);
 124     if (c == NULL)
 125         return ENOMEM;
 126     _kafs_foldup(c, c);
 127     krb5_appdefault_string (context, "libkafs",
 128                             c,
 129                             "afs-use-524", "2b", &val);
 130     free(c);
 131
 132     if (strcasecmp(val, "local") == 0 ||
 133         strcasecmp(val, "2b") == 0)
 134         ret = v5_to_kt(cred, uid, kt, 1);
 135     else if(strcasecmp(val, "yes") == 0 ||
 136             strcasecmp(val, "true") == 0 ||
 137             atoi(val)) {
 138         struct credentials cred4;
 139
 140         if (id == NULL)
 141             ret = krb524_convert_creds_kdc(context, cred, &cred4);
 142         else
 143             ret = krb524_convert_creds_kdc_ccache(context, id, cred, &cred4);
 144         if (ret)
 145             goto out;
 146
 147         ret = _kafs_v4_to_kt(&cred4, uid, kt);
 148     } else
 149         ret = v5_to_kt(cred, uid, kt, 0);
 150
 151  out:
 152     free(val);
 153     return ret;
 154 }
 155
 156
 157 /*
 158  *
 159  */
 160
 161 static int
 162 get_cred(struct kafs_data *data, const char *name, const char *inst,
 163          const char *realm, uid_t uid, struct kafs_token *kt)
 164 {
 165     krb5_error_code ret;
 166     krb5_creds in_creds, *out_creds;
 167     struct krb5_kafs_data *d = data->data;
 168
 169     memset(&in_creds, 0, sizeof(in_creds));
 170
 171     ret = krb5_make_principal(d->context, &in_creds.server,
 172                               realm, name, inst, NULL);
 173     if(ret)
 174         return ret;
 175     ret = krb5_cc_get_principal(d->context, d->id, &in_creds.client);
 176     if(ret){
 177         krb5_free_principal(d->context, in_creds.server);
 178         return ret;
 179     }
 180     in_creds.session.keytype = ETYPE_DES_CBC_CRC;
 181     ret = krb5_get_credentials(d->context, 0, d->id, &in_creds, &out_creds);
 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 krb5_error_code
 195 afslog_uid_int(struct kafs_data *data, const char *cell, const char *rh,
 196                uid_t uid, const char *homedir)
 197 {
 198     krb5_error_code ret;
 199     struct kafs_token kt;
 200     krb5_principal princ;
 201     const char *trealm; /* ticket realm */
 202     struct krb5_kafs_data *d = data->data;
 203
 204     if (cell == 0 || cell[0] == 0)
 205         return _kafs_afslog_all_local_cells (data, uid, homedir);
 206
 207     ret = krb5_cc_get_principal (d->context, d->id, &princ);
 208     if (ret)
 209         return ret;
 210
 211     trealm = krb5_principal_get_realm (d->context, princ);
 212
 213     kt.ticket = NULL;
 214     ret = _kafs_get_cred(data, cell, d->realm, trealm, uid, &kt);
 215     krb5_free_principal (d->context, princ);
 216
 217     if(ret == 0) {
 218         ret = kafs_settoken_rxkad(cell, &kt.ct, kt.ticket, kt.ticket_len);
 219         free(kt.ticket);
 220     }
 221     return ret;
 222 }
 223
 224 static char *
 225 get_realm(struct kafs_data *data, const char *host)
 226 {
 227     struct krb5_kafs_data *d = data->data;
 228     krb5_realm *realms;
 229     char *r;
 230     if(krb5_get_host_realm(d->context, host, &realms))
 231         return NULL;
 232     r = strdup(realms[0]);
 233     krb5_free_host_realm(d->context, realms);
 234     return r;
 235 }
 236
 237 krb5_error_code
 238 krb5_afslog_uid_home(krb5_context context,
 239                      krb5_ccache id,
 240                      const char *cell,
 241                      krb5_const_realm realm,
 242                      uid_t uid,
 243                      const char *homedir)
 244 {
 245     struct kafs_data kd;
 246     struct krb5_kafs_data d;
 247     krb5_error_code ret;
 248
 249     kd.name = "krb5";
 250     kd.afslog_uid = afslog_uid_int;
 251     kd.get_cred = get_cred;
 252     kd.get_realm = get_realm;
 253     kd.data = &d;
 254     if (context == NULL) {
 255         ret = krb5_init_context(&d.context);
 256         if (ret)
 257             return ret;
 258     } else
 259         d.context = context;
 260     if (id == NULL) {
 261         ret = krb5_cc_default(d.context, &d.id);
 262         if (ret)
 263             goto out;
 264     } else
 265         d.id = id;
 266     d.realm = realm;
 267     ret = afslog_uid_int(&kd, cell, 0, uid, homedir);
 268     if (id == NULL)
 269         krb5_cc_close(context, d.id);
 270  out:
 271     if (context == NULL)
 272         krb5_free_context(d.context);
 273     return ret;
 274 }
 275
 276 krb5_error_code
 277 krb5_afslog_uid(krb5_context context,
 278                 krb5_ccache id,
 279                 const char *cell,
 280                 krb5_const_realm realm,
 281                 uid_t uid)
 282 {
 283     return krb5_afslog_uid_home (context, id, cell, realm, uid, NULL);
 284 }
 285
 286 krb5_error_code
 287 krb5_afslog(krb5_context context,
 288             krb5_ccache id,
 289             const char *cell,
 290             krb5_const_realm realm)
 291 {
 292     return krb5_afslog_uid (context, id, cell, realm, getuid());
 293 }
 294
 295 krb5_error_code
 296 krb5_afslog_home(krb5_context context,
 297                  krb5_ccache id,
 298                  const char *cell,
 299                  krb5_const_realm realm,
 300                  const char *homedir)
 301 {
 302     return krb5_afslog_uid_home (context, id, cell, realm, getuid(), homedir);
 303 }
 304
 305 /*
 306  *
 307  */
 308
 309 krb5_error_code
 310 krb5_realm_of_cell(const char *cell, char **realm)
 311 {
 312     struct kafs_data kd;
 313
 314     kd.name = "krb5";
 315     kd.get_realm = get_realm;
 316     return _kafs_realm_of_cell(&kd, cell, realm);
 317 }
 318
 319 /*
 320  *
 321  */
 322
 323 int
 324 kafs_settoken5(krb5_context context, const char *cell, uid_t uid,
 325                krb5_creds *cred)
 326 {
 327     struct kafs_token kt;
 328     int ret;
 329
 330     ret = v5_convert(context, NULL, cred, uid, cell, &kt);
 331     if (ret)
 332         return ret;
 333
 334     ret = kafs_settoken_rxkad(cell, &kt.ct, kt.ticket, kt.ticket_len);
 335
 336     free(kt.ticket);
 337
 338     return ret;
 339 }