kdc/kerberos5.c

   1 /*
   2  * Copyright (c) 1997-2007 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 "kdc_locl.h"
  35
  36 RCSID("$Id$");
  37
  38 #define MAX_TIME ((time_t)((1U << 31) - 1))
  39
  40 void
  41 _kdc_fix_time(time_t **t)
  42 {
  43     if(*t == NULL){
  44         ALLOC(*t);
  45         **t = MAX_TIME;
  46     }
  47     if(**t == 0) **t = MAX_TIME; /* fix for old clients */
  48 }
  49
  50 static int
  51 realloc_method_data(METHOD_DATA *md)
  52 {
  53     PA_DATA *pa;
  54     pa = realloc(md->val, (md->len + 1) * sizeof(*md->val));
  55     if(pa == NULL)
  56         return ENOMEM;
  57     md->val = pa;
  58     md->len++;
  59     return 0;
  60 }
  61
  62 static void
  63 set_salt_padata (METHOD_DATA *md, Salt *salt)
  64 {
  65     if (salt) {
  66         realloc_method_data(md);
  67         md->val[md->len - 1].padata_type = salt->type;
  68         der_copy_octet_string(&salt->salt,
  69                               &md->val[md->len - 1].padata_value);
  70     }
  71 }
  72
  73 const PA_DATA*
  74 _kdc_find_padata(const KDC_REQ *req, int *start, int type)
  75 {
  76     if (req->padata == NULL)
  77         return NULL;
  78
  79     while(*start < req->padata->len){
  80         (*start)++;
  81         if(req->padata->val[*start - 1].padata_type == type)
  82             return &req->padata->val[*start - 1];
  83     }
  84     return NULL;
  85 }
  86
  87 /*
  88  * This is a hack to allow predefined weak services, like afs to
  89  * still use weak types
  90  */
  91
  92 krb5_boolean
  93 _kdc_is_weak_exception(krb5_principal principal, krb5_enctype etype)
  94 {
  95     if (principal->name.name_string.len > 0 &&
  96         strcmp(principal->name.name_string.val[0], "afs") == 0 &&
  97         (etype == ETYPE_DES_CBC_CRC
  98          || etype == ETYPE_DES_CBC_MD4
  99          || etype == ETYPE_DES_CBC_MD5))
 100         return TRUE;
 101     return FALSE;
 102 }
 103
 104
 105 /*
 106  * Detect if `key' is the using the the precomputed `default_salt'.
 107  */
 108
 109 static krb5_boolean
 110 is_default_salt_p(const krb5_salt *default_salt, const Key *key)
 111 {
 112     if (key->salt == NULL)
 113         return TRUE;
 114     if (default_salt->salttype != key->salt->type)
 115         return FALSE;
 116     if (krb5_data_cmp(&default_salt->saltvalue, &key->salt->salt))
 117         return FALSE;
 118     return TRUE;
 119 }
 120
 121 /*
 122  * return the first appropriate key of `princ' in `ret_key'.  Look for
 123  * all the etypes in (`etypes', `len'), stopping as soon as we find
 124  * one, but preferring one that has default salt
 125  */
 126
 127 krb5_error_code
 128 _kdc_find_etype(krb5_context context, const hdb_entry_ex *princ,
 129                 krb5_enctype *etypes, unsigned len,
 130                 Key **ret_key, krb5_enctype *ret_etype)
 131 {
 132     int i;
 133     krb5_error_code ret = KRB5KDC_ERR_ETYPE_NOSUPP;
 134     krb5_salt def_salt;
 135
 136     krb5_get_pw_salt (context, princ->entry.principal, &def_salt);
 137
 138     for(i = 0; ret != 0 && i < len ; i++) {
 139         Key *key = NULL;
 140
 141         if (krb5_enctype_valid(context, etypes[i]) != 0 &&
 142             !_kdc_is_weak_exception(princ->entry.principal, etypes[i]))
 143             continue;
 144
 145         while (hdb_next_enctype2key(context, &princ->entry, etypes[i], &key) == 0) {
 146             if (key->key.keyvalue.length == 0) {
 147                 ret = KRB5KDC_ERR_NULL_KEY;
 148                 continue;
 149             }
 150             *ret_key   = key;
 151             *ret_etype = etypes[i];
 152             ret = 0;
 153             if (is_default_salt_p(&def_salt, key)) {
 154                 krb5_free_salt (context, def_salt);
 155                 return ret;
 156             }
 157         }
 158     }
 159     krb5_free_salt (context, def_salt);
 160     return ret;
 161 }
 162
 163 krb5_error_code
 164 _kdc_make_anonymous_principalname (PrincipalName *pn)
 165 {
 166     pn->name_type = KRB5_NT_PRINCIPAL;
 167     pn->name_string.len = 1;
 168     pn->name_string.val = malloc(sizeof(*pn->name_string.val));
 169     if (pn->name_string.val == NULL)
 170         return ENOMEM;
 171     pn->name_string.val[0] = strdup("anonymous");
 172     if (pn->name_string.val[0] == NULL) {
 173         free(pn->name_string.val);
 174         pn->name_string.val = NULL;
 175         return ENOMEM;
 176     }
 177     return 0;
 178 }
 179
 180 void
 181 _kdc_log_timestamp(krb5_context context,
 182                    krb5_kdc_configuration *config,
 183                    const char *type,
 184                    KerberosTime authtime, KerberosTime *starttime,
 185                    KerberosTime endtime, KerberosTime *renew_till)
 186 {
 187     char authtime_str[100], starttime_str[100],
 188         endtime_str[100], renewtime_str[100];
 189
 190     krb5_format_time(context, authtime,
 191                      authtime_str, sizeof(authtime_str), TRUE);
 192     if (starttime)
 193         krb5_format_time(context, *starttime,
 194                          starttime_str, sizeof(starttime_str), TRUE);
 195     else
 196         strlcpy(starttime_str, "unset", sizeof(starttime_str));
 197     krb5_format_time(context, endtime,
 198                      endtime_str, sizeof(endtime_str), TRUE);
 199     if (renew_till)
 200         krb5_format_time(context, *renew_till,
 201                          renewtime_str, sizeof(renewtime_str), TRUE);
 202     else
 203         strlcpy(renewtime_str, "unset", sizeof(renewtime_str));
 204
 205     kdc_log(context, config, 5,
 206             "%s authtime: %s starttime: %s endtime: %s renew till: %s",
 207             type, authtime_str, starttime_str, endtime_str, renewtime_str);
 208 }
 209
 210 static void
 211 log_patypes(krb5_context context,
 212             krb5_kdc_configuration *config,
 213             METHOD_DATA *padata)
 214 {
 215     struct rk_strpool *p = NULL;
 216     char *str;
 217     int i;
 218
 219     for (i = 0; i < padata->len; i++) {
 220         switch(padata->val[i].padata_type) {
 221         case KRB5_PADATA_PK_AS_REQ:
 222             p = rk_strpoolprintf(p, "PK-INIT(ietf)");
 223             break;
 224         case KRB5_PADATA_PK_AS_REQ_WIN:
 225             p = rk_strpoolprintf(p, "PK-INIT(win2k)");
 226             break;
 227         case KRB5_PADATA_PA_PK_OCSP_RESPONSE:
 228             p = rk_strpoolprintf(p, "OCSP");
 229             break;
 230         case KRB5_PADATA_ENC_TIMESTAMP:
 231             p = rk_strpoolprintf(p, "encrypted-timestamp");
 232             break;
 233         default:
 234             p = rk_strpoolprintf(p, "%d", padata->val[i].padata_type);
 235             break;
 236         }
 237         if (p && i + 1 < padata->len)
 238             p = rk_strpoolprintf(p, ", ");
 239         if (p == NULL) {
 240             kdc_log(context, config, 0, "out of memory");
 241             return;
 242         }
 243     }
 244     if (p == NULL)
 245         p = rk_strpoolprintf(p, "none");
 246
 247     str = rk_strpoolcollect(p);
 248     kdc_log(context, config, 0, "Client sent patypes: %s", str);
 249     free(str);
 250 }
 251
 252 /*
 253  *
 254  */
 255
 256
 257 krb5_error_code
 258 _kdc_encode_reply(krb5_context context,
 259                   krb5_kdc_configuration *config,
 260                   KDC_REP *rep, const EncTicketPart *et, EncKDCRepPart *ek,
 261                   krb5_enctype etype,
 262                   int skvno, const EncryptionKey *skey,
 263                   int ckvno, const EncryptionKey *reply_key,
 264                   const char **e_text,
 265                   krb5_data *reply)
 266 {
 267     unsigned char *buf;
 268     size_t buf_size;
 269     size_t len;
 270     krb5_error_code ret;
 271     krb5_crypto crypto;
 272
 273     ASN1_MALLOC_ENCODE(EncTicketPart, buf, buf_size, et, &len, ret);
 274     if(ret) {
 275         kdc_log(context, config, 0, "Failed to encode ticket: %s",
 276                 krb5_get_err_text(context, ret));
 277         return ret;
 278     }
 279     if(buf_size != len) {
 280         free(buf);
 281         kdc_log(context, config, 0, "Internal error in ASN.1 encoder");
 282         *e_text = "KDC internal error";
 283         return KRB5KRB_ERR_GENERIC;
 284     }
 285
 286     ret = krb5_crypto_init(context, skey, etype, &crypto);
 287     if (ret) {
 288         free(buf);
 289         kdc_log(context, config, 0, "krb5_crypto_init failed: %s",
 290                 krb5_get_err_text(context, ret));
 291         return ret;
 292     }
 293
 294     ret = krb5_encrypt_EncryptedData(context,
 295                                      crypto,
 296                                      KRB5_KU_TICKET,
 297                                      buf,
 298                                      len,
 299                                      skvno,
 300                                      &rep->ticket.enc_part);
 301     free(buf);
 302     krb5_crypto_destroy(context, crypto);
 303     if(ret) {
 304         kdc_log(context, config, 0, "Failed to encrypt data: %s",
 305                 krb5_get_err_text(context, ret));
 306         return ret;
 307     }
 308
 309     if(rep->msg_type == krb_as_rep && !config->encode_as_rep_as_tgs_rep)
 310         ASN1_MALLOC_ENCODE(EncASRepPart, buf, buf_size, ek, &len, ret);
 311     else
 312         ASN1_MALLOC_ENCODE(EncTGSRepPart, buf, buf_size, ek, &len, ret);
 313     if(ret) {
 314         kdc_log(context, config, 0, "Failed to encode KDC-REP: %s",
 315                 krb5_get_err_text(context, ret));
 316         return ret;
 317     }
 318     if(buf_size != len) {
 319         free(buf);
 320         kdc_log(context, config, 0, "Internal error in ASN.1 encoder");
 321         *e_text = "KDC internal error";
 322         return KRB5KRB_ERR_GENERIC;
 323     }
 324     ret = krb5_crypto_init(context, reply_key, 0, &crypto);
 325     if (ret) {
 326         free(buf);
 327         kdc_log(context, config, 0, "krb5_crypto_init failed: %s",
 328                 krb5_get_err_text(context, ret));
 329         return ret;
 330     }
 331     if(rep->msg_type == krb_as_rep) {
 332         krb5_encrypt_EncryptedData(context,
 333                                    crypto,
 334                                    KRB5_KU_AS_REP_ENC_PART,
 335                                    buf,
 336                                    len,
 337                                    ckvno,
 338                                    &rep->enc_part);
 339         free(buf);
 340         ASN1_MALLOC_ENCODE(AS_REP, buf, buf_size, rep, &len, ret);
 341     } else {
 342         krb5_encrypt_EncryptedData(context,
 343                                    crypto,
 344                                    KRB5_KU_TGS_REP_ENC_PART_SESSION,
 345                                    buf,
 346                                    len,
 347                                    ckvno,
 348                                    &rep->enc_part);
 349         free(buf);
 350         ASN1_MALLOC_ENCODE(TGS_REP, buf, buf_size, rep, &len, ret);
 351     }
 352     krb5_crypto_destroy(context, crypto);
 353     if(ret) {
 354         kdc_log(context, config, 0, "Failed to encode KDC-REP: %s",
 355                 krb5_get_err_text(context, ret));
 356         return ret;
 357     }
 358     if(buf_size != len) {
 359         free(buf);
 360         kdc_log(context, config, 0, "Internal error in ASN.1 encoder");
 361         *e_text = "KDC internal error";
 362         return KRB5KRB_ERR_GENERIC;
 363     }
 364     reply->data = buf;
 365     reply->length = buf_size;
 366     return 0;
 367 }
 368
 369 /*
 370  * Return 1 if the client have only older enctypes, this is for
 371  * determining if the server should send ETYPE_INFO2 or not.
 372  */
 373
 374 static int
 375 older_enctype(krb5_enctype enctype)
 376 {
 377     switch (enctype) {
 378     case ETYPE_DES_CBC_CRC:
 379     case ETYPE_DES_CBC_MD4:
 380     case ETYPE_DES_CBC_MD5:
 381     case ETYPE_DES3_CBC_SHA1:
 382     case ETYPE_ARCFOUR_HMAC_MD5:
 383     case ETYPE_ARCFOUR_HMAC_MD5_56:
 384     /*
 385      * The following three is "old" windows enctypes and is needed for
 386      * windows 2000 hosts.
 387      */
 388     case ETYPE_ARCFOUR_MD4:
 389     case ETYPE_ARCFOUR_HMAC_OLD:
 390     case ETYPE_ARCFOUR_HMAC_OLD_EXP:
 391         return 1;
 392     default:
 393         return 0;
 394     }
 395 }
 396
 397 /*
 398  *
 399  */
 400
 401 static krb5_error_code
 402 make_etype_info_entry(krb5_context context, ETYPE_INFO_ENTRY *ent, Key *key)
 403 {
 404     ent->etype = key->key.keytype;
 405     if(key->salt){
 406 #if 0
 407         ALLOC(ent->salttype);
 408
 409         if(key->salt->type == hdb_pw_salt)
 410             *ent->salttype = 0; /* or 1? or NULL? */
 411         else if(key->salt->type == hdb_afs3_salt)
 412             *ent->salttype = 2;
 413         else {
 414             kdc_log(context, config, 0, "unknown salt-type: %d",
 415                     key->salt->type);
 416             return KRB5KRB_ERR_GENERIC;
 417         }
 418         /* according to `the specs', we can't send a salt if
 419            we have AFS3 salted key, but that requires that you
 420            *know* what cell you are using (e.g by assuming
 421            that the cell is the same as the realm in lower
 422            case) */
 423 #elif 0
 424         ALLOC(ent->salttype);
 425         *ent->salttype = key->salt->type;
 426 #else
 427         /*
 428          * We shouldn't sent salttype since it is incompatible with the
 429          * specification and it breaks windows clients.  The afs
 430          * salting problem is solved by using KRB5-PADATA-AFS3-SALT
 431          * implemented in Heimdal 0.7 and later.
 432          */
 433         ent->salttype = NULL;
 434 #endif
 435         krb5_copy_data(context, &key->salt->salt,
 436                        &ent->salt);
 437     } else {
 438         /* we return no salt type at all, as that should indicate
 439          * the default salt type and make everybody happy.  some
 440          * systems (like w2k) dislike being told the salt type
 441          * here. */
 442
 443         ent->salttype = NULL;
 444         ent->salt = NULL;
 445     }
 446     return 0;
 447 }
 448
 449 static krb5_error_code
 450 get_pa_etype_info(krb5_context context,
 451                   krb5_kdc_configuration *config,
 452                   METHOD_DATA *md, Key *ckey)
 453 {
 454     krb5_error_code ret = 0;
 455     ETYPE_INFO pa;
 456     unsigned char *buf;
 457     size_t len;
 458
 459
 460     pa.len = 1;
 461     pa.val = calloc(1, sizeof(pa.val[0]));
 462     if(pa.val == NULL)
 463         return ENOMEM;
 464
 465     ret = make_etype_info_entry(context, &pa.val[0], ckey);
 466     if (ret) {
 467         free_ETYPE_INFO(&pa);
 468         return ret;
 469     }
 470
 471     ASN1_MALLOC_ENCODE(ETYPE_INFO, buf, len, &pa, &len, ret);
 472     free_ETYPE_INFO(&pa);
 473     if(ret)
 474         return ret;
 475     ret = realloc_method_data(md);
 476     if(ret) {
 477         free(buf);
 478         return ret;
 479     }
 480     md->val[md->len - 1].padata_type = KRB5_PADATA_ETYPE_INFO;
 481     md->val[md->len - 1].padata_value.length = len;
 482     md->val[md->len - 1].padata_value.data = buf;
 483     return 0;
 484 }
 485
 486 /*
 487  *
 488  */
 489
 490 extern int _krb5_AES_string_to_default_iterator;
 491
 492 static krb5_error_code
 493 make_etype_info2_entry(ETYPE_INFO2_ENTRY *ent, Key *key)
 494 {
 495     ent->etype = key->key.keytype;
 496     if(key->salt) {
 497         ALLOC(ent->salt);
 498         if (ent->salt == NULL)
 499             return ENOMEM;
 500         *ent->salt = malloc(key->salt->salt.length + 1);
 501         if (*ent->salt == NULL) {
 502             free(ent->salt);
 503             ent->salt = NULL;
 504             return ENOMEM;
 505         }
 506         memcpy(*ent->salt, key->salt->salt.data, key->salt->salt.length);
 507         (*ent->salt)[key->salt->salt.length] = '\0';
 508     } else
 509         ent->salt = NULL;
 510
 511     ent->s2kparams = NULL;
 512
 513     switch (key->key.keytype) {
 514     case ETYPE_AES128_CTS_HMAC_SHA1_96:
 515     case ETYPE_AES256_CTS_HMAC_SHA1_96:
 516         ALLOC(ent->s2kparams);
 517         if (ent->s2kparams == NULL)
 518             return ENOMEM;
 519         ent->s2kparams->length = 4;
 520         ent->s2kparams->data = malloc(ent->s2kparams->length);
 521         if (ent->s2kparams->data == NULL) {
 522             free(ent->s2kparams);
 523             ent->s2kparams = NULL;
 524             return ENOMEM;
 525         }
 526         _krb5_put_int(ent->s2kparams->data,
 527                       _krb5_AES_string_to_default_iterator,
 528                       ent->s2kparams->length);
 529         break;
 530     case ETYPE_DES_CBC_CRC:
 531     case ETYPE_DES_CBC_MD4:
 532     case ETYPE_DES_CBC_MD5:
 533         /* Check if this was a AFS3 salted key */
 534         if(key->salt && key->salt->type == hdb_afs3_salt){
 535             ALLOC(ent->s2kparams);
 536             if (ent->s2kparams == NULL)
 537                 return ENOMEM;
 538             ent->s2kparams->length = 1;
 539             ent->s2kparams->data = malloc(ent->s2kparams->length);
 540             if (ent->s2kparams->data == NULL) {
 541                 free(ent->s2kparams);
 542                 ent->s2kparams = NULL;
 543                 return ENOMEM;
 544             }
 545             _krb5_put_int(ent->s2kparams->data,
 546                           1,
 547                           ent->s2kparams->length);
 548         }
 549         break;
 550     default:
 551         break;
 552     }
 553     return 0;
 554 }
 555
 556 /*
 557  * Return an ETYPE-INFO2. Enctypes are storted the same way as in the
 558  * database (client supported enctypes first, then the unsupported
 559  * enctypes).
 560  */
 561
 562 static krb5_error_code
 563 get_pa_etype_info2(krb5_context context,
 564                    krb5_kdc_configuration *config,
 565                    METHOD_DATA *md, Key *ckey)
 566 {
 567     krb5_error_code ret = 0;
 568     ETYPE_INFO2 pa;
 569     unsigned char *buf;
 570     size_t len;
 571
 572     pa.len = 1;
 573     pa.val = calloc(1, sizeof(pa.val[0]));
 574     if(pa.val == NULL)
 575         return ENOMEM;
 576
 577     ret = make_etype_info2_entry(&pa.val[0], ckey);
 578     if (ret) {
 579         free_ETYPE_INFO2(&pa);
 580         return ret;
 581     }
 582
 583     ASN1_MALLOC_ENCODE(ETYPE_INFO2, buf, len, &pa, &len, ret);
 584     free_ETYPE_INFO2(&pa);
 585     if(ret)
 586         return ret;
 587     ret = realloc_method_data(md);
 588     if(ret) {
 589         free(buf);
 590         return ret;
 591     }
 592     md->val[md->len - 1].padata_type = KRB5_PADATA_ETYPE_INFO2;
 593     md->val[md->len - 1].padata_value.length = len;
 594     md->val[md->len - 1].padata_value.data = buf;
 595     return 0;
 596 }
 597
 598 /*
 599  *
 600  */
 601
 602 static void
 603 log_as_req(krb5_context context,
 604            krb5_kdc_configuration *config,
 605            krb5_enctype cetype,
 606            krb5_enctype setype,
 607            const KDC_REQ_BODY *b)
 608 {
 609     krb5_error_code ret;
 610     struct rk_strpool *p;
 611     char *str;
 612     int i;
 613
 614     p = rk_strpoolprintf(NULL, "%s", "Client supported enctypes: ");
 615
 616     for (i = 0; i < b->etype.len; i++) {
 617         ret = krb5_enctype_to_string(context, b->etype.val[i], &str);
 618         if (ret == 0) {
 619             p = rk_strpoolprintf(p, "%s", str);
 620             free(str);
 621         } else
 622             p = rk_strpoolprintf(p, "%d", b->etype.val[i]);
 623         if (p && i + 1 < b->etype.len)
 624             p = rk_strpoolprintf(p, ", ");
 625         if (p == NULL) {
 626             kdc_log(context, config, 0, "out of memory");
 627             return;
 628         }
 629     }
 630     if (p == NULL)
 631         p = rk_strpoolprintf(p, "no encryption types");
 632
 633     {
 634         char *cet;
 635         char *set;
 636
 637         ret = krb5_enctype_to_string(context, cetype, &cet);
 638         if(ret == 0) {
 639             ret = krb5_enctype_to_string(context, setype, &set);
 640             if (ret == 0) {
 641                 p = rk_strpoolprintf(p, ", using %s/%s", cet, set);
 642                 free(set);
 643             }
 644             free(cet);
 645         }
 646         if (ret != 0)
 647             p = rk_strpoolprintf(p, ", using enctypes %d/%d",
 648                                  cetype, setype);
 649     }
 650
 651     str = rk_strpoolcollect(p);
 652     kdc_log(context, config, 0, "%s", str);
 653     free(str);
 654
 655     {
 656         char fixedstr[128];
 657         unparse_flags(KDCOptions2int(b->kdc_options), asn1_KDCOptions_units(),
 658                       fixedstr, sizeof(fixedstr));
 659         if(*fixedstr)
 660             kdc_log(context, config, 0, "Requested flags: %s", fixedstr);
 661     }
 662 }
 663
 664 /*
 665  * verify the flags on `client' and `server', returning 0
 666  * if they are OK and generating an error messages and returning
 667  * and error code otherwise.
 668  */
 669
 670 krb5_error_code
 671 _kdc_check_flags(krb5_context context,
 672                  krb5_kdc_configuration *config,
 673                  hdb_entry_ex *client_ex, const char *client_name,
 674                  hdb_entry_ex *server_ex, const char *server_name,
 675                  krb5_boolean is_as_req)
 676 {
 677     if(client_ex != NULL) {
 678         hdb_entry *client = &client_ex->entry;
 679
 680         /* check client */
 681         if (client->flags.invalid) {
 682             kdc_log(context, config, 0,
 683                     "Client (%s) has invalid bit set", client_name);
 684             return KRB5KDC_ERR_POLICY;
 685         }
 686
 687         if(!client->flags.client){
 688             kdc_log(context, config, 0,
 689                     "Principal may not act as client -- %s", client_name);
 690             return KRB5KDC_ERR_POLICY;
 691         }
 692
 693         if (client->valid_start && *client->valid_start > kdc_time) {
 694             char starttime_str[100];
 695             krb5_format_time(context, *client->valid_start,
 696                              starttime_str, sizeof(starttime_str), TRUE);
 697             kdc_log(context, config, 0,
 698                     "Client not yet valid until %s -- %s",
 699                     starttime_str, client_name);
 700             return KRB5KDC_ERR_CLIENT_NOTYET;
 701         }
 702
 703         if (client->valid_end && *client->valid_end < kdc_time) {
 704             char endtime_str[100];
 705             krb5_format_time(context, *client->valid_end,
 706                              endtime_str, sizeof(endtime_str), TRUE);
 707             kdc_log(context, config, 0,
 708                     "Client expired at %s -- %s",
 709                     endtime_str, client_name);
 710             return KRB5KDC_ERR_NAME_EXP;
 711         }
 712
 713         if (client->pw_end && *client->pw_end < kdc_time
 714             && (server_ex == NULL || !server_ex->entry.flags.change_pw)) {
 715             char pwend_str[100];
 716             krb5_format_time(context, *client->pw_end,
 717                              pwend_str, sizeof(pwend_str), TRUE);
 718             kdc_log(context, config, 0,
 719                     "Client's key has expired at %s -- %s",
 720                     pwend_str, client_name);
 721             return KRB5KDC_ERR_KEY_EXPIRED;
 722         }
 723     }
 724
 725     /* check server */
 726
 727     if (server_ex != NULL) {
 728         hdb_entry *server = &server_ex->entry;
 729
 730         if (server->flags.invalid) {
 731             kdc_log(context, config, 0,
 732                     "Server has invalid flag set -- %s", server_name);
 733             return KRB5KDC_ERR_POLICY;
 734         }
 735
 736         if(!server->flags.server){
 737             kdc_log(context, config, 0,
 738                     "Principal may not act as server -- %s", server_name);
 739             return KRB5KDC_ERR_POLICY;
 740         }
 741
 742         if(!is_as_req && server->flags.initial) {
 743             kdc_log(context, config, 0,
 744                     "AS-REQ is required for server -- %s", server_name);
 745             return KRB5KDC_ERR_POLICY;
 746         }
 747
 748         if (server->valid_start && *server->valid_start > kdc_time) {
 749             char starttime_str[100];
 750             krb5_format_time(context, *server->valid_start,
 751                              starttime_str, sizeof(starttime_str), TRUE);
 752             kdc_log(context, config, 0,
 753                     "Server not yet valid until %s -- %s",
 754                     starttime_str, server_name);
 755             return KRB5KDC_ERR_SERVICE_NOTYET;
 756         }
 757
 758         if (server->valid_end && *server->valid_end < kdc_time) {
 759             char endtime_str[100];
 760             krb5_format_time(context, *server->valid_end,
 761                              endtime_str, sizeof(endtime_str), TRUE);
 762             kdc_log(context, config, 0,
 763                     "Server expired at %s -- %s",
 764                     endtime_str, server_name);
 765             return KRB5KDC_ERR_SERVICE_EXP;
 766         }
 767
 768         if (server->pw_end && *server->pw_end < kdc_time) {
 769             char pwend_str[100];
 770             krb5_format_time(context, *server->pw_end,
 771                              pwend_str, sizeof(pwend_str), TRUE);
 772             kdc_log(context, config, 0,
 773                     "Server's key has expired at -- %s",
 774                     pwend_str, server_name);
 775             return KRB5KDC_ERR_KEY_EXPIRED;
 776         }
 777     }
 778     return 0;
 779 }
 780
 781 /*
 782  * Return TRUE if `from' is part of `addresses' taking into consideration
 783  * the configuration variables that tells us how strict we should be about
 784  * these checks
 785  */
 786
 787 krb5_boolean
 788 _kdc_check_addresses(krb5_context context,
 789                      krb5_kdc_configuration *config,
 790                      HostAddresses *addresses, const struct sockaddr *from)
 791 {
 792     krb5_error_code ret;
 793     krb5_address addr;
 794     krb5_boolean result;
 795     krb5_boolean only_netbios = TRUE;
 796     int i;
 797
 798     if(config->check_ticket_addresses == 0)
 799         return TRUE;
 800
 801     if(addresses == NULL)
 802         return config->allow_null_ticket_addresses;
 803
 804     for (i = 0; i < addresses->len; ++i) {
 805         if (addresses->val[i].addr_type != KRB5_ADDRESS_NETBIOS) {
 806             only_netbios = FALSE;
 807         }
 808     }
 809
 810     /* Windows sends it's netbios name, which I can only assume is
 811      * used for the 'allowed workstations' check.  This is painful,
 812      * but we still want to check IP addresses if they happen to be
 813      * present.
 814      */
 815
 816     if(only_netbios)
 817         return config->allow_null_ticket_addresses;
 818
 819     ret = krb5_sockaddr2address (context, from, &addr);
 820     if(ret)
 821         return FALSE;
 822
 823     result = krb5_address_search(context, &addr, addresses);
 824     krb5_free_address (context, &addr);
 825     return result;
 826 }
 827
 828 /*
 829  *
 830  */
 831
 832 static krb5_boolean
 833 send_pac_p(krb5_context context, KDC_REQ *req)
 834 {
 835     krb5_error_code ret;
 836     PA_PAC_REQUEST pacreq;
 837     const PA_DATA *pa;
 838     int i = 0;
 839
 840     pa = _kdc_find_padata(req, &i, KRB5_PADATA_PA_PAC_REQUEST);
 841     if (pa == NULL)
 842         return TRUE;
 843
 844     ret = decode_PA_PAC_REQUEST(pa->padata_value.data,
 845                                 pa->padata_value.length,
 846                                 &pacreq,
 847                                 NULL);
 848     if (ret)
 849         return TRUE;
 850     i = pacreq.include_pac;
 851     free_PA_PAC_REQUEST(&pacreq);
 852     if (i == 0)
 853         return FALSE;
 854     return TRUE;
 855 }
 856
 857 krb5_boolean
 858 _kdc_is_anonymous(krb5_context context, krb5_principal principal)
 859 {
 860     if (principal->name.name_type != KRB5_NT_WELLKNOWN ||
 861         principal->name.name_string.len != 2 ||
 862         strcmp(principal->name.name_string.val[0], KRB5_WELLKNOWN_NAME) != 0 ||
 863         strcmp(principal->name.name_string.val[1], KRB5_ANON_NAME) != 0)
 864         return 0;
 865     return 1;
 866 }
 867
 868 /*
 869  *
 870  */
 871
 872 krb5_error_code
 873 _kdc_as_rep(krb5_context context,
 874             krb5_kdc_configuration *config,
 875             KDC_REQ *req,
 876             const krb5_data *req_buffer,
 877             krb5_data *reply,
 878             const char *from,
 879             struct sockaddr *from_addr,
 880             int datagram_reply)
 881 {
 882     KDC_REQ_BODY *b = &req->req_body;
 883     AS_REP rep;
 884     KDCOptions f = b->kdc_options;
 885     hdb_entry_ex *client = NULL, *server = NULL;
 886     krb5_enctype cetype, setype, sessionetype;
 887     krb5_data e_data;
 888     EncTicketPart et;
 889     EncKDCRepPart ek;
 890     krb5_principal client_princ = NULL, server_princ = NULL;
 891     char *client_name = NULL, *server_name = NULL;
 892     krb5_error_code ret = 0;
 893     const char *e_text = NULL;
 894     krb5_crypto crypto;
 895     Key *ckey, *skey;
 896     EncryptionKey *reply_key;
 897     int flags = 0;
 898 #ifdef PKINIT
 899     pk_client_params *pkp = NULL;
 900 #endif
 901
 902     memset(&rep, 0, sizeof(rep));
 903     krb5_data_zero(&e_data);
 904
 905     if (f.canonicalize)
 906         flags |= HDB_F_CANON;
 907
 908     if(b->sname == NULL){
 909         ret = KRB5KRB_ERR_GENERIC;
 910         e_text = "No server in request";
 911     } else{
 912         ret = _krb5_principalname2krb5_principal (context,
 913                                                   &server_princ,
 914                                                   *(b->sname),
 915                                                   b->realm);
 916         if (ret == 0)
 917             ret = krb5_unparse_name(context, server_princ, &server_name);
 918     }
 919     if (ret) {
 920         kdc_log(context, config, 0,
 921                 "AS-REQ malformed server name from %s", from);
 922         goto out;
 923     }
 924
 925     if(b->cname == NULL){
 926         ret = KRB5KRB_ERR_GENERIC;
 927         e_text = "No client in request";
 928     } else {
 929         ret = _krb5_principalname2krb5_principal (context,
 930                                                   &client_princ,
 931                                                   *(b->cname),
 932                                                   b->realm);
 933         if (ret)
 934             goto out;
 935
 936         ret = krb5_unparse_name(context, client_princ, &client_name);
 937     }
 938     if (ret) {
 939         kdc_log(context, config, 0,
 940                 "AS-REQ malformed client name from %s", from);
 941         goto out;
 942     }
 943
 944     kdc_log(context, config, 0, "AS-REQ %s from %s for %s",
 945             client_name, from, server_name);
 946
 947     /*
 948      *
 949      */
 950
 951     if (_kdc_is_anonymous(context, client_princ)) {
 952         if (!b->kdc_options.request_anonymous) {
 953             kdc_log(context, config, 0, "Anonymous ticket w/o anonymous flag");
 954             ret = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
 955             goto out;
 956         }
 957     } else if (b->kdc_options.request_anonymous) {
 958         kdc_log(context, config, 0,
 959                 "Request for a anonymous ticket with non "
 960                 "anonymous client name: %s", client_name);
 961         ret = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
 962         goto out;
 963     }
 964
 965     /*
 966      *
 967      */
 968
 969     ret = _kdc_db_fetch(context, config, client_princ,
 970                         HDB_F_GET_CLIENT | flags, NULL, &client);
 971     if(ret){
 972         kdc_log(context, config, 0, "UNKNOWN -- %s: %s", client_name,
 973                 krb5_get_err_text(context, ret));
 974         ret = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
 975         goto out;
 976     }
 977
 978     ret = _kdc_db_fetch(context, config, server_princ,
 979                         HDB_F_GET_SERVER|HDB_F_GET_KRBTGT,
 980                         NULL, &server);
 981     if(ret){
 982         kdc_log(context, config, 0, "UNKNOWN -- %s: %s", server_name,
 983                 krb5_get_err_text(context, ret));
 984         ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
 985         goto out;
 986     }
 987
 988     memset(&et, 0, sizeof(et));
 989     memset(&ek, 0, sizeof(ek));
 990
 991     /*
 992      * Find the client key for reply encryption and pa-type salt, Pick
 993      * the client key upfront before the other keys because that is
 994      * going to affect what enctypes we are going to use in
 995      * ETYPE-INFO{,2}.
 996      */
 997
 998     ret = _kdc_find_etype(context, client, b->etype.val, b->etype.len,
 999                           &ckey, &cetype);
1000     if (ret) {
1001         kdc_log(context, config, 0,
1002                 "Client (%s) has no support for etypes", client_name);
1003         goto out;
1004     }
1005
1006     /*
1007      * Pre-auth processing
1008      */
1009
1010     if(req->padata){
1011         int i;
1012         const PA_DATA *pa;
1013         int found_pa = 0;
1014
1015         log_patypes(context, config, req->padata);
1016
1017 #ifdef PKINIT
1018         kdc_log(context, config, 5,
1019                 "Looking for PKINIT pa-data -- %s", client_name);
1020
1021         e_text = "No PKINIT PA found";
1022
1023         i = 0;
1024         pa = _kdc_find_padata(req, &i, KRB5_PADATA_PK_AS_REQ);
1025         if (pa == NULL) {
1026             i = 0;
1027             pa = _kdc_find_padata(req, &i, KRB5_PADATA_PK_AS_REQ_WIN);
1028         }
1029         if (pa) {
1030             char *client_cert = NULL;
1031
1032             ret = _kdc_pk_rd_padata(context, config, req, pa, client, &pkp);
1033             if (ret) {
1034                 ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
1035                 kdc_log(context, config, 5,
1036                         "Failed to decode PKINIT PA-DATA -- %s",
1037                         client_name);
1038                 goto ts_enc;
1039             }
1040             if (ret == 0 && pkp == NULL)
1041                 goto ts_enc;
1042
1043             ret = _kdc_pk_check_client(context,
1044                                        config,
1045                                        client,
1046                                        pkp,
1047                                        &client_cert);
1048             if (ret) {
1049                 e_text = "PKINIT certificate not allowed to "
1050                     "impersonate principal";
1051                 _kdc_pk_free_client_param(context, pkp);
1052
1053                 kdc_log(context, config, 0, "%s", e_text);
1054                 pkp = NULL;
1055                 goto out;
1056             }
1057
1058             found_pa = 1;
1059             et.flags.pre_authent = 1;
1060             kdc_log(context, config, 0,
1061                     "PKINIT pre-authentication succeeded -- %s using %s",
1062                     client_name, client_cert);
1063             free(client_cert);
1064             if (pkp)
1065                 goto preauth_done;
1066         }
1067     ts_enc:
1068 #endif
1069         kdc_log(context, config, 5, "Looking for ENC-TS pa-data -- %s",
1070                 client_name);
1071
1072         i = 0;
1073         e_text = "No ENC-TS found";
1074         while((pa = _kdc_find_padata(req, &i, KRB5_PADATA_ENC_TIMESTAMP))){
1075             krb5_data ts_data;
1076             PA_ENC_TS_ENC p;
1077             size_t len;
1078             EncryptedData enc_data;
1079             Key *pa_key;
1080             char *str;
1081
1082             found_pa = 1;
1083
1084             if (b->kdc_options.request_anonymous) {
1085                 ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
1086                 kdc_log(context, config, 0, "ENC-TS doesn't support anon");
1087                 goto out;
1088             }
1089
1090             ret = decode_EncryptedData(pa->padata_value.data,
1091                                        pa->padata_value.length,
1092                                        &enc_data,
1093                                        &len);
1094             if (ret) {
1095                 ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
1096                 kdc_log(context, config, 5, "Failed to decode PA-DATA -- %s",
1097                         client_name);
1098                 goto out;
1099             }
1100
1101             ret = hdb_enctype2key(context, &client->entry,
1102                                   enc_data.etype, &pa_key);
1103             if(ret){
1104                 char *estr;
1105                 e_text = "No key matches pa-data";
1106                 ret = KRB5KDC_ERR_ETYPE_NOSUPP;
1107                 if(krb5_enctype_to_string(context, enc_data.etype, &estr))
1108                     estr = NULL;
1109                 if(estr == NULL)
1110                     kdc_log(context, config, 5,
1111                             "No client key matching pa-data (%d) -- %s",
1112                             enc_data.etype, client_name);
1113                 else
1114                     kdc_log(context, config, 5,
1115                             "No client key matching pa-data (%s) -- %s",
1116                             estr, client_name);
1117                 free(estr);
1118
1119                 free_EncryptedData(&enc_data);
1120                 continue;
1121             }
1122
1123         try_next_key:
1124             ret = krb5_crypto_init(context, &pa_key->key, 0, &crypto);
1125             if (ret) {
1126                 kdc_log(context, config, 0, "krb5_crypto_init failed: %s",
1127                         krb5_get_err_text(context, ret));
1128                 free_EncryptedData(&enc_data);
1129                 continue;
1130             }
1131
1132             ret = krb5_decrypt_EncryptedData (context,
1133                                               crypto,
1134                                               KRB5_KU_PA_ENC_TIMESTAMP,
1135                                               &enc_data,
1136                                               &ts_data);
1137             krb5_crypto_destroy(context, crypto);
1138             /*
1139              * Since the user might have several keys with the same
1140              * enctype but with diffrent salting, we need to try all
1141              * the keys with the same enctype.
1142              */
1143             if(ret){
1144                 krb5_error_code ret2;
1145                 ret2 = krb5_enctype_to_string(context,
1146                                               pa_key->key.keytype, &str);
1147                 if (ret2)
1148                     str = NULL;
1149                 kdc_log(context, config, 5,
1150                         "Failed to decrypt PA-DATA -- %s "
1151                         "(enctype %s) error %s",
1152                         client_name,
1153                         str ? str : "unknown enctype",
1154                         krb5_get_err_text(context, ret));
1155                 free(str);
1156
1157                 if(hdb_next_enctype2key(context, &client->entry,
1158                                         enc_data.etype, &pa_key) == 0)
1159                     goto try_next_key;
1160                 e_text = "Failed to decrypt PA-DATA";
1161
1162                 free_EncryptedData(&enc_data);
1163                 ret = KRB5KDC_ERR_PREAUTH_FAILED;
1164                 continue;
1165             }
1166             free_EncryptedData(&enc_data);
1167             ret = decode_PA_ENC_TS_ENC(ts_data.data,
1168                                        ts_data.length,
1169                                        &p,
1170                                        &len);
1171             krb5_data_free(&ts_data);
1172             if(ret){
1173                 e_text = "Failed to decode PA-ENC-TS-ENC";
1174                 ret = KRB5KDC_ERR_PREAUTH_FAILED;
1175                 kdc_log(context, config,
1176                         5, "Failed to decode PA-ENC-TS_ENC -- %s",
1177                         client_name);
1178                 continue;
1179             }
1180             free_PA_ENC_TS_ENC(&p);
1181             if (abs(kdc_time - p.patimestamp) > context->max_skew) {
1182                 char client_time[100];
1183
1184                 krb5_format_time(context, p.patimestamp,
1185                                  client_time, sizeof(client_time), TRUE);
1186
1187                 ret = KRB5KRB_AP_ERR_SKEW;
1188                 kdc_log(context, config, 0,
1189                         "Too large time skew, "
1190                         "client time %s is out by %u > %u seconds -- %s",
1191                         client_time,
1192                         (unsigned)abs(kdc_time - p.patimestamp),
1193                         context->max_skew,
1194                         client_name);
1195 #if 0
1196                 /* This code is from samba, needs testing */
1197                 /*
1198                  * the following is needed to make windows clients
1199                  * to retry using the timestamp in the error message
1200                  *
1201                  * this is maybe a bug in windows to not trying when e_text
1202                  * is present...
1203                  */
1204                 e_text = NULL;
1205 #else
1206                 e_text = "Too large time skew";
1207 #endif
1208                 goto out;
1209             }
1210             et.flags.pre_authent = 1;
1211
1212             ret = krb5_enctype_to_string(context,pa_key->key.keytype, &str);
1213             if (ret)
1214                 str = NULL;
1215
1216             kdc_log(context, config, 2,
1217                     "ENC-TS Pre-authentication succeeded -- %s using %s",
1218                     client_name, str ? str : "unknown enctype");
1219             free(str);
1220             break;
1221         }
1222 #ifdef PKINIT
1223     preauth_done:
1224 #endif
1225         if(found_pa == 0 && config->require_preauth)
1226             goto use_pa;
1227         /* We come here if we found a pa-enc-timestamp, but if there
1228            was some problem with it, other than too large skew */
1229         if(found_pa && et.flags.pre_authent == 0){
1230             kdc_log(context, config, 0, "%s -- %s", e_text, client_name);
1231             e_text = NULL;
1232             goto out;
1233         }
1234     }else if (config->require_preauth
1235               || b->kdc_options.request_anonymous /* hack to force anon */
1236               || client->entry.flags.require_preauth
1237               || server->entry.flags.require_preauth) {
1238         METHOD_DATA method_data;
1239         PA_DATA *pa;
1240         unsigned char *buf;
1241         size_t len;
1242
1243     use_pa:
1244         method_data.len = 0;
1245         method_data.val = NULL;
1246
1247         ret = realloc_method_data(&method_data);
1248         if (ret) {
1249             free_METHOD_DATA(&method_data);
1250             goto out;
1251         }
1252         pa = &method_data.val[method_data.len-1];
1253         pa->padata_type         = KRB5_PADATA_ENC_TIMESTAMP;
1254         pa->padata_value.length = 0;
1255         pa->padata_value.data   = NULL;
1256
1257 #ifdef PKINIT
1258         ret = realloc_method_data(&method_data);
1259         if (ret) {
1260             free_METHOD_DATA(&method_data);
1261             goto out;
1262         }
1263         pa = &method_data.val[method_data.len-1];
1264         pa->padata_type         = KRB5_PADATA_PK_AS_REQ;
1265         pa->padata_value.length = 0;
1266         pa->padata_value.data   = NULL;
1267
1268         ret = realloc_method_data(&method_data);
1269         if (ret) {
1270             free_METHOD_DATA(&method_data);
1271             goto out;
1272         }
1273         pa = &method_data.val[method_data.len-1];
1274         pa->padata_type         = KRB5_PADATA_PK_AS_REQ_WIN;
1275         pa->padata_value.length = 0;
1276         pa->padata_value.data   = NULL;
1277 #endif
1278
1279         /*
1280          * If there is a client key, send ETYPE_INFO{,2}
1281          */
1282         if (ckey) {
1283
1284             /*
1285              * RFC4120 requires:
1286              * - If the client only knows about old enctypes, then send
1287              *   both info replies (we send 'info' first in the list).
1288              * - If the client is 'modern', because it knows about 'new'
1289              *   enctype types, then only send the 'info2' reply.
1290              *
1291              * Before we send the full list of etype-info data, we pick
1292              * the client key we would have used anyway below, just pick
1293              * that instead.
1294              */
1295
1296             if (older_enctype(ckey->key.keytype)) {
1297                 ret = get_pa_etype_info(context, config,
1298                                         &method_data, ckey);
1299                 if (ret) {
1300                     free_METHOD_DATA(&method_data);
1301                     goto out;
1302                 }
1303             }
1304             ret = get_pa_etype_info2(context, config,
1305                                      &method_data, ckey);
1306             if (ret) {
1307                 free_METHOD_DATA(&method_data);
1308                 goto out;
1309             }
1310         }
1311
1312         ASN1_MALLOC_ENCODE(METHOD_DATA, buf, len, &method_data, &len, ret);
1313         free_METHOD_DATA(&method_data);
1314
1315         e_data.data   = buf;
1316         e_data.length = len;
1317         e_text ="Need to use PA-ENC-TIMESTAMP/PA-PK-AS-REQ",
1318
1319         ret = KRB5KDC_ERR_PREAUTH_REQUIRED;
1320
1321         kdc_log(context, config, 0,
1322                 "No preauth found, returning PREAUTH-REQUIRED -- %s",
1323                 client_name);
1324         goto out;
1325     }
1326
1327     /*
1328      * Verify flags after the user been required to prove its identity
1329      * with in a preauth mech.
1330      */
1331
1332     ret = _kdc_check_flags(context, config,
1333                            client, client_name,
1334                            server, server_name,
1335                            TRUE);
1336     if(ret)
1337         goto out;
1338
1339     ret = _kdc_windc_client_access(context, client, req, &e_data);
1340     if(ret)
1341         goto out;
1342
1343     /*
1344      * Selelct the best encryption type for the KDC with out regard to
1345      * the client since the client never needs to read that data.
1346      */
1347
1348     ret = _kdc_get_preferred_key(context, config,
1349                                  server, server_name,
1350                                  &setype, &skey);
1351     if(ret)
1352         goto out;
1353
1354     /*
1355      * Select a session enctype from the list of the crypto systems
1356      * supported enctype, is supported by the client and is one of the
1357      * enctype of the enctype of the krbtgt.
1358      *
1359      * The later is used as a hint what enctype all KDC are supporting
1360      * to make sure a newer version of KDC wont generate a session
1361      * enctype that and older version of a KDC in the same realm can't
1362      * decrypt.
1363      *
1364      * But if the KDC admin is paranoid and doesn't want to have "no
1365      * the best" enctypes on the krbtgt, lets save the best pick from
1366      * the client list and hope that that will work for any other
1367      * KDCs.
1368      */
1369     {
1370         const krb5_enctype *p;
1371         krb5_enctype clientbest = ETYPE_NULL;
1372         int i, j;
1373
1374         p = krb5_kerberos_enctypes(context);
1375
1376         sessionetype = ETYPE_NULL;
1377
1378         for (i = 0; p[i] != ETYPE_NULL && sessionetype == ETYPE_NULL; i++) {
1379             if (krb5_enctype_valid(context, p[i]) != 0)
1380                 continue;
1381
1382             for (j = 0; j < b->etype.len && sessionetype == ETYPE_NULL; j++) {
1383                 Key *dummy;
1384                 /* check with client */
1385                 if (p[i] != b->etype.val[j])
1386                     continue;
1387                 /* save best of union of { client, crypto system } */
1388                 if (clientbest == ETYPE_NULL)
1389                     clientbest = p[i];
1390                 /* check with krbtgt */
1391                 ret = hdb_enctype2key(context, &server->entry, p[i], &dummy);
1392                 if (ret)
1393                     continue;
1394                 sessionetype = p[i];
1395             }
1396         }
1397         /* if krbtgt had no shared keys with client, pick clients best */
1398         if (clientbest != ETYPE_NULL && sessionetype == ETYPE_NULL) {
1399             sessionetype = clientbest;
1400         } else if (sessionetype == ETYPE_NULL) {
1401             kdc_log(context, config, 0,
1402                     "Client (%s) from %s has no common enctypes with KDC"
1403                     "to use for the session key",
1404                     client_name, from);
1405             goto out;
1406         }
1407     }
1408
1409     log_as_req(context, config, cetype, setype, b);
1410
1411     if(f.renew || f.validate || f.proxy || f.forwarded || f.enc_tkt_in_skey
1412        || (f.request_anonymous && !config->allow_anonymous)) {
1413         ret = KRB5KDC_ERR_BADOPTION;
1414         kdc_log(context, config, 0, "Bad KDC options -- %s", client_name);
1415         goto out;
1416     }
1417
1418     rep.pvno = 5;
1419     rep.msg_type = krb_as_rep;
1420
1421     ret = copy_Realm(&client->entry.principal->realm, &rep.crealm);
1422     if (ret)
1423         goto out;
1424     ret = _krb5_principal2principalname(&rep.cname, client->entry.principal);
1425     if (ret)
1426         goto out;
1427
1428     rep.ticket.tkt_vno = 5;
1429     copy_Realm(&server->entry.principal->realm, &rep.ticket.realm);
1430     _krb5_principal2principalname(&rep.ticket.sname,
1431                                   server->entry.principal);
1432     /* java 1.6 expects the name to be the same type, lets allow that
1433      * uncomplicated name-types. */
1434 #define CNT(sp,t) (((sp)->sname->name_type) == KRB5_NT_##t)
1435     if (CNT(b, UNKNOWN) || CNT(b, PRINCIPAL) || CNT(b, SRV_INST) || CNT(b, SRV_HST) || CNT(b, SRV_XHST))
1436         rep.ticket.sname.name_type = b->sname->name_type;
1437 #undef CNT
1438
1439     et.flags.initial = 1;
1440     if(client->entry.flags.forwardable && server->entry.flags.forwardable)
1441         et.flags.forwardable = f.forwardable;
1442     else if (f.forwardable) {
1443         ret = KRB5KDC_ERR_POLICY;
1444         kdc_log(context, config, 0,
1445                 "Ticket may not be forwardable -- %s", client_name);
1446         goto out;
1447     }
1448     if(client->entry.flags.proxiable && server->entry.flags.proxiable)
1449         et.flags.proxiable = f.proxiable;
1450     else if (f.proxiable) {
1451         ret = KRB5KDC_ERR_POLICY;
1452         kdc_log(context, config, 0,
1453                 "Ticket may not be proxiable -- %s", client_name);
1454         goto out;
1455     }
1456     if(client->entry.flags.postdate && server->entry.flags.postdate)
1457         et.flags.may_postdate = f.allow_postdate;
1458     else if (f.allow_postdate){
1459         ret = KRB5KDC_ERR_POLICY;
1460         kdc_log(context, config, 0,
1461                 "Ticket may not be postdatable -- %s", client_name);
1462         goto out;
1463     }
1464
1465     /* check for valid set of addresses */
1466     if(!_kdc_check_addresses(context, config, b->addresses, from_addr)) {
1467         ret = KRB5KRB_AP_ERR_BADADDR;
1468         kdc_log(context, config, 0,
1469                 "Bad address list requested -- %s", client_name);
1470         goto out;
1471     }
1472
1473     ret = copy_PrincipalName(&rep.cname, &et.cname);
1474     if (ret)
1475         goto out;
1476     ret = copy_Realm(&rep.crealm, &et.crealm);
1477     if (ret)
1478         goto out;
1479
1480     {
1481         time_t start;
1482         time_t t;
1483
1484         start = et.authtime = kdc_time;
1485
1486         if(f.postdated && req->req_body.from){
1487             ALLOC(et.starttime);
1488             start = *et.starttime = *req->req_body.from;
1489             et.flags.invalid = 1;
1490             et.flags.postdated = 1; /* XXX ??? */
1491         }
1492         _kdc_fix_time(&b->till);
1493         t = *b->till;
1494
1495         /* be careful not overflowing */
1496
1497         if(client->entry.max_life)
1498             t = start + min(t - start, *client->entry.max_life);
1499         if(server->entry.max_life)
1500             t = start + min(t - start, *server->entry.max_life);
1501 #if 0
1502         t = min(t, start + realm->max_life);
1503 #endif
1504         et.endtime = t;
1505         if(f.renewable_ok && et.endtime < *b->till){
1506             f.renewable = 1;
1507             if(b->rtime == NULL){
1508                 ALLOC(b->rtime);
1509                 *b->rtime = 0;
1510             }
1511             if(*b->rtime < *b->till)
1512                 *b->rtime = *b->till;
1513         }
1514         if(f.renewable && b->rtime){
1515             t = *b->rtime;
1516             if(t == 0)
1517                 t = MAX_TIME;
1518             if(client->entry.max_renew)
1519                 t = start + min(t - start, *client->entry.max_renew);
1520             if(server->entry.max_renew)
1521                 t = start + min(t - start, *server->entry.max_renew);
1522 #if 0
1523             t = min(t, start + realm->max_renew);
1524 #endif
1525             ALLOC(et.renew_till);
1526             *et.renew_till = t;
1527             et.flags.renewable = 1;
1528         }
1529     }
1530
1531     if (f.request_anonymous)
1532         et.flags.anonymous = 1;
1533
1534     if(b->addresses){
1535         ALLOC(et.caddr);
1536         copy_HostAddresses(b->addresses, et.caddr);
1537     }
1538
1539     et.transited.tr_type = DOMAIN_X500_COMPRESS;
1540     krb5_data_zero(&et.transited.contents);
1541
1542     /* The MIT ASN.1 library (obviously) doesn't tell lengths encoded
1543      * as 0 and as 0x80 (meaning indefinite length) apart, and is thus
1544      * incapable of correctly decoding SEQUENCE OF's of zero length.
1545      *
1546      * To fix this, always send at least one no-op last_req
1547      *
1548      * If there's a pw_end or valid_end we will use that,
1549      * otherwise just a dummy lr.
1550      */
1551     ek.last_req.val = malloc(2 * sizeof(*ek.last_req.val));
1552     if (ek.last_req.val == NULL) {
1553         ret = ENOMEM;
1554         goto out;
1555     }
1556     ek.last_req.len = 0;
1557     if (client->entry.pw_end
1558         && (config->kdc_warn_pwexpire == 0
1559             || kdc_time + config->kdc_warn_pwexpire >= *client->entry.pw_end)) {
1560         ek.last_req.val[ek.last_req.len].lr_type  = LR_PW_EXPTIME;
1561         ek.last_req.val[ek.last_req.len].lr_value = *client->entry.pw_end;
1562         ++ek.last_req.len;
1563     }
1564     if (client->entry.valid_end) {
1565         ek.last_req.val[ek.last_req.len].lr_type  = LR_ACCT_EXPTIME;
1566         ek.last_req.val[ek.last_req.len].lr_value = *client->entry.valid_end;
1567         ++ek.last_req.len;
1568     }
1569     if (ek.last_req.len == 0) {
1570         ek.last_req.val[ek.last_req.len].lr_type  = LR_NONE;
1571         ek.last_req.val[ek.last_req.len].lr_value = 0;
1572         ++ek.last_req.len;
1573     }
1574     ek.nonce = b->nonce;
1575     if (client->entry.valid_end || client->entry.pw_end) {
1576         ALLOC(ek.key_expiration);
1577         if (client->entry.valid_end) {
1578             if (client->entry.pw_end)
1579                 *ek.key_expiration = min(*client->entry.valid_end,
1580                                          *client->entry.pw_end);
1581             else
1582                 *ek.key_expiration = *client->entry.valid_end;
1583         } else
1584             *ek.key_expiration = *client->entry.pw_end;
1585     } else
1586         ek.key_expiration = NULL;
1587     ek.flags = et.flags;
1588     ek.authtime = et.authtime;
1589     if (et.starttime) {
1590         ALLOC(ek.starttime);
1591         *ek.starttime = *et.starttime;
1592     }
1593     ek.endtime = et.endtime;
1594     if (et.renew_till) {
1595         ALLOC(ek.renew_till);
1596         *ek.renew_till = *et.renew_till;
1597     }
1598     copy_Realm(&rep.ticket.realm, &ek.srealm);
1599     copy_PrincipalName(&rep.ticket.sname, &ek.sname);
1600     if(et.caddr){
1601         ALLOC(ek.caddr);
1602         copy_HostAddresses(et.caddr, ek.caddr);
1603     }
1604
1605     ALLOC(rep.padata);
1606     rep.padata->len = 0;
1607     rep.padata->val = NULL;
1608
1609 #if PKINIT
1610     if (pkp) {
1611         e_text = "Failed to build PK-INIT reply";
1612         ret = _kdc_pk_mk_pa_reply(context, config, pkp, client,
1613                                   sessionetype, req, req_buffer,
1614                                   &reply_key, &et.key, rep.padata);
1615         if (ret)
1616             goto out;
1617         ret = _kdc_add_inital_verified_cas(context,
1618                                            config,
1619                                            pkp,
1620                                            &et);
1621         if (ret)
1622             goto out;
1623     } else
1624 #endif
1625     if (ckey) {
1626         reply_key = &ckey->key;
1627         ret = krb5_generate_random_keyblock(context, sessionetype, &et.key);
1628         if (ret)
1629             goto out;
1630     } else {
1631         e_text = "Client have no reply key";
1632         ret = KRB5KDC_ERR_CLIENT_NOTYET;
1633         goto out;
1634     }
1635
1636     ret = copy_EncryptionKey(&et.key, &ek.key);
1637     if (ret)
1638         goto out;
1639
1640     if (ckey)
1641         set_salt_padata (rep.padata, ckey->salt);
1642
1643     /* Add signing of alias referral */
1644     if (f.canonicalize) {
1645         PA_ClientCanonicalized canon;
1646         krb5_data data;
1647         PA_DATA pa;
1648         krb5_crypto crypto;
1649         size_t len;
1650
1651         memset(&canon, 0, sizeof(canon));
1652
1653         canon.names.requested_name = *b->cname;
1654         canon.names.mapped_name = client->entry.principal->name;
1655
1656         ASN1_MALLOC_ENCODE(PA_ClientCanonicalizedNames, data.data, data.length,
1657                            &canon.names, &len, ret);
1658         if (ret)
1659             goto out;
1660         if (data.length != len)
1661             krb5_abortx(context, "internal asn.1 error");
1662
1663         /* sign using "returned session key" */
1664         ret = krb5_crypto_init(context, &et.key, 0, &crypto);
1665         if (ret) {
1666             free(data.data);
1667             goto out;
1668         }
1669
1670         ret = krb5_create_checksum(context, crypto,
1671                                    KRB5_KU_CANONICALIZED_NAMES, 0,
1672                                    data.data, data.length,
1673                                    &canon.canon_checksum);
1674         free(data.data);
1675         krb5_crypto_destroy(context, crypto);
1676         if (ret)
1677             goto out;
1678
1679         ASN1_MALLOC_ENCODE(PA_ClientCanonicalized, data.data, data.length,
1680                            &canon, &len, ret);
1681         free_Checksum(&canon.canon_checksum);
1682         if (ret)
1683             goto out;
1684         if (data.length != len)
1685             krb5_abortx(context, "internal asn.1 error");
1686
1687         pa.padata_type = KRB5_PADATA_CLIENT_CANONICALIZED;
1688         pa.padata_value = data;
1689         ret = add_METHOD_DATA(rep.padata, &pa);
1690         free(data.data);
1691         if (ret)
1692             goto out;
1693     }
1694
1695     if (rep.padata->len == 0) {
1696         free(rep.padata);
1697         rep.padata = NULL;
1698     }
1699
1700     /* Add the PAC */
1701     if (send_pac_p(context, req)) {
1702         krb5_pac p = NULL;
1703         krb5_data data;
1704
1705         ret = _kdc_pac_generate(context, client, &p);
1706         if (ret) {
1707             kdc_log(context, config, 0, "PAC generation failed for -- %s",
1708                     client_name);
1709             goto out;
1710         }
1711         if (p != NULL) {
1712             ret = _krb5_pac_sign(context, p, et.authtime,
1713                                  client->entry.principal,
1714                                  &skey->key, /* Server key */
1715                                  &skey->key, /* FIXME: should be krbtgt key */
1716                                  &data);
1717             krb5_pac_free(context, p);
1718             if (ret) {
1719                 kdc_log(context, config, 0, "PAC signing failed for -- %s",
1720                         client_name);
1721                 goto out;
1722             }
1723
1724             ret = _kdc_tkt_add_if_relevant_ad(context, &et,
1725                                               KRB5_AUTHDATA_WIN2K_PAC,
1726                                               &data);
1727             krb5_data_free(&data);
1728             if (ret)
1729                 goto out;
1730         }
1731     }
1732
1733     _kdc_log_timestamp(context, config, "AS-REQ", et.authtime, et.starttime,
1734                        et.endtime, et.renew_till);
1735
1736     /* do this as the last thing since this signs the EncTicketPart */
1737     ret = _kdc_add_KRB5SignedPath(context,
1738                                   config,
1739                                   server,
1740                                   setype,
1741                                   NULL,
1742                                   NULL,
1743                                   &et);
1744     if (ret)
1745         goto out;
1746
1747     ret = _kdc_encode_reply(context, config,
1748                             &rep, &et, &ek, setype, server->entry.kvno,
1749                             &skey->key, client->entry.kvno,
1750                             reply_key, &e_text, reply);
1751     free_EncTicketPart(&et);
1752     free_EncKDCRepPart(&ek);
1753     if (ret)
1754         goto out;
1755
1756     /* */
1757     if (datagram_reply && reply->length > config->max_datagram_reply_length) {
1758         krb5_data_free(reply);
1759         ret = KRB5KRB_ERR_RESPONSE_TOO_BIG;
1760         e_text = "Reply packet too large";
1761     }
1762
1763 out:
1764     free_AS_REP(&rep);
1765     if(ret){
1766         krb5_mk_error(context,
1767                       ret,
1768                       e_text,
1769                       (e_data.data ? &e_data : NULL),
1770                       client_princ,
1771                       server_princ,
1772                       NULL,
1773                       NULL,
1774                       reply);
1775         ret = 0;
1776     }
1777 #ifdef PKINIT
1778     if (pkp)
1779         _kdc_pk_free_client_param(context, pkp);
1780 #endif
1781     if (e_data.data)
1782         free(e_data.data);
1783     if (client_princ)
1784         krb5_free_principal(context, client_princ);
1785     free(client_name);
1786     if (server_princ)
1787         krb5_free_principal(context, server_princ);
1788     free(server_name);
1789     if(client)
1790         _kdc_free_ent(context, client);
1791     if(server)
1792         _kdc_free_ent(context, server);
1793     return ret;
1794 }
1795
1796 /*
1797  * Add the AuthorizationData `data´ of `type´ to the last element in
1798  * the sequence of authorization_data in `tkt´ wrapped in an IF_RELEVANT
1799  */
1800
1801 krb5_error_code
1802 _kdc_tkt_add_if_relevant_ad(krb5_context context,
1803                             EncTicketPart *tkt,
1804                             int type,
1805                             const krb5_data *data)
1806 {
1807     krb5_error_code ret;
1808     size_t size;
1809
1810     if (tkt->authorization_data == NULL) {
1811         tkt->authorization_data = calloc(1, sizeof(*tkt->authorization_data));
1812         if (tkt->authorization_data == NULL) {
1813             krb5_set_error_message(context, ENOMEM, "out of memory");
1814             return ENOMEM;
1815         }
1816     }
1817
1818     /* add the entry to the last element */
1819     {
1820         AuthorizationData ad = { 0, NULL };
1821         AuthorizationDataElement ade;
1822
1823         ade.ad_type = type;
1824         ade.ad_data = *data;
1825
1826         ret = add_AuthorizationData(&ad, &ade);
1827         if (ret) {
1828             krb5_set_error_message(context, ret, "add AuthorizationData failed");
1829             return ret;
1830         }
1831
1832         ade.ad_type = KRB5_AUTHDATA_IF_RELEVANT;
1833
1834         ASN1_MALLOC_ENCODE(AuthorizationData,
1835                            ade.ad_data.data, ade.ad_data.length,
1836                            &ad, &size, ret);
1837         free_AuthorizationData(&ad);
1838         if (ret) {
1839             krb5_set_error_message(context, ret, "ASN.1 encode of "
1840                                    "AuthorizationData failed");
1841             return ret;
1842         }
1843         if (ade.ad_data.length != size)
1844             krb5_abortx(context, "internal asn.1 encoder error");
1845
1846         ret = add_AuthorizationData(tkt->authorization_data, &ade);
1847         der_free_octet_string(&ade.ad_data);
1848         if (ret) {
1849             krb5_set_error_message(context, ret, "add AuthorizationData failed");
1850             return ret;
1851         }
1852     }
1853
1854     return 0;
1855 }