2 * Copyright (c) 2006 - 2007 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
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.
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.
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
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30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include "krb5_locl.h"
37 RCSID("$Id: pac.c 22562 2008-02-03 17:38:35Z lha $");
39 struct PAC_INFO_BUFFER {
49 struct PAC_INFO_BUFFER buffers[1];
52 struct krb5_pac_data {
55 struct PAC_INFO_BUFFER *server_checksum;
56 struct PAC_INFO_BUFFER *privsvr_checksum;
57 struct PAC_INFO_BUFFER *logon_name;
60 #define PAC_ALIGNMENT 8
62 #define PACTYPE_SIZE 8
63 #define PAC_INFO_BUFFER_SIZE 16
65 #define PAC_SERVER_CHECKSUM 6
66 #define PAC_PRIVSVR_CHECKSUM 7
67 #define PAC_LOGON_NAME 10
68 #define PAC_CONSTRAINED_DELEGATION 11
70 #define CHECK(r,f,l) \
72 if (((r) = f ) != 0) { \
73 krb5_clear_error_string(context); \
78 static const char zeros[PAC_ALIGNMENT] = { 0 };
85 krb5_pac_parse(krb5_context context, const void *ptr, size_t len,
90 krb5_storage *sp = NULL;
91 uint32_t i, tmp, tmp2, header_end;
93 p = calloc(1, sizeof(*p));
96 krb5_set_error_string(context, "out of memory");
100 sp = krb5_storage_from_readonly_mem(ptr, len);
103 krb5_set_error_string(context, "out of memory");
106 krb5_storage_set_flags(sp, KRB5_STORAGE_BYTEORDER_LE);
108 CHECK(ret, krb5_ret_uint32(sp, &tmp), out);
109 CHECK(ret, krb5_ret_uint32(sp, &tmp2), out);
111 krb5_set_error_string(context, "PAC have too few buffer");
112 ret = EINVAL; /* Too few buffers */
116 krb5_set_error_string(context, "PAC have wrong version");
117 ret = EINVAL; /* Wrong version */
122 sizeof(*p->pac) + (sizeof(p->pac->buffers[0]) * (tmp - 1)));
123 if (p->pac == NULL) {
124 krb5_set_error_string(context, "out of memory");
129 p->pac->numbuffers = tmp;
130 p->pac->version = tmp2;
132 header_end = PACTYPE_SIZE + (PAC_INFO_BUFFER_SIZE * p->pac->numbuffers);
133 if (header_end > len) {
138 for (i = 0; i < p->pac->numbuffers; i++) {
139 CHECK(ret, krb5_ret_uint32(sp, &p->pac->buffers[i].type), out);
140 CHECK(ret, krb5_ret_uint32(sp, &p->pac->buffers[i].buffersize), out);
141 CHECK(ret, krb5_ret_uint32(sp, &p->pac->buffers[i].offset_lo), out);
142 CHECK(ret, krb5_ret_uint32(sp, &p->pac->buffers[i].offset_hi), out);
144 /* consistency checks */
145 if (p->pac->buffers[i].offset_lo & (PAC_ALIGNMENT - 1)) {
146 krb5_set_error_string(context, "PAC out of allignment");
150 if (p->pac->buffers[i].offset_hi) {
151 krb5_set_error_string(context, "PAC high offset set");
155 if (p->pac->buffers[i].offset_lo > len) {
156 krb5_set_error_string(context, "PAC offset off end");
160 if (p->pac->buffers[i].offset_lo < header_end) {
161 krb5_set_error_string(context, "PAC offset inside header: %d %d",
162 p->pac->buffers[i].offset_lo, header_end);
166 if (p->pac->buffers[i].buffersize > len - p->pac->buffers[i].offset_lo){
167 krb5_set_error_string(context, "PAC length off end");
172 /* let save pointer to data we need later */
173 if (p->pac->buffers[i].type == PAC_SERVER_CHECKSUM) {
174 if (p->server_checksum) {
175 krb5_set_error_string(context, "PAC have two server checksums");
179 p->server_checksum = &p->pac->buffers[i];
180 } else if (p->pac->buffers[i].type == PAC_PRIVSVR_CHECKSUM) {
181 if (p->privsvr_checksum) {
182 krb5_set_error_string(context, "PAC have two KDC checksums");
186 p->privsvr_checksum = &p->pac->buffers[i];
187 } else if (p->pac->buffers[i].type == PAC_LOGON_NAME) {
189 krb5_set_error_string(context, "PAC have two logon names");
193 p->logon_name = &p->pac->buffers[i];
197 ret = krb5_data_copy(&p->data, ptr, len);
201 krb5_storage_free(sp);
208 krb5_storage_free(sp);
220 krb5_pac_init(krb5_context context, krb5_pac *pac)
225 p = calloc(1, sizeof(*p));
227 krb5_set_error_string(context, "out of memory");
231 p->pac = calloc(1, sizeof(*p->pac));
232 if (p->pac == NULL) {
234 krb5_set_error_string(context, "out of memory");
238 ret = krb5_data_alloc(&p->data, PACTYPE_SIZE);
242 krb5_set_error_string(context, "out of memory");
252 krb5_pac_add_buffer(krb5_context context, krb5_pac p,
253 uint32_t type, const krb5_data *data)
257 size_t len, offset, header_end, old_end;
260 len = p->pac->numbuffers;
262 ptr = realloc(p->pac,
263 sizeof(*p->pac) + (sizeof(p->pac->buffers[0]) * len));
265 krb5_set_error_string(context, "out of memory");
270 for (i = 0; i < len; i++)
271 p->pac->buffers[i].offset_lo += PAC_INFO_BUFFER_SIZE;
273 offset = p->data.length + PAC_INFO_BUFFER_SIZE;
275 p->pac->buffers[len].type = type;
276 p->pac->buffers[len].buffersize = data->length;
277 p->pac->buffers[len].offset_lo = offset;
278 p->pac->buffers[len].offset_hi = 0;
280 old_end = p->data.length;
281 len = p->data.length + data->length + PAC_INFO_BUFFER_SIZE;
282 if (len < p->data.length) {
283 krb5_set_error_string(context, "integer overrun");
287 /* align to PAC_ALIGNMENT */
288 len = ((len + PAC_ALIGNMENT - 1) / PAC_ALIGNMENT) * PAC_ALIGNMENT;
290 ret = krb5_data_realloc(&p->data, len);
292 krb5_set_error_string(context, "out of memory");
297 * make place for new PAC INFO BUFFER header
299 header_end = PACTYPE_SIZE + (PAC_INFO_BUFFER_SIZE * p->pac->numbuffers);
300 memmove((unsigned char *)p->data.data + header_end + PAC_INFO_BUFFER_SIZE,
301 (unsigned char *)p->data.data + header_end ,
302 old_end - header_end);
303 memset((unsigned char *)p->data.data + header_end, 0, PAC_INFO_BUFFER_SIZE);
306 * copy in new data part
309 memcpy((unsigned char *)p->data.data + offset,
310 data->data, data->length);
311 memset((unsigned char *)p->data.data + offset + data->length,
312 0, p->data.length - offset - data->length);
314 p->pac->numbuffers += 1;
320 krb5_pac_get_buffer(krb5_context context, krb5_pac p,
321 uint32_t type, krb5_data *data)
327 * Hide the checksums from external consumers
330 if (type == PAC_PRIVSVR_CHECKSUM || type == PAC_SERVER_CHECKSUM) {
331 ret = krb5_data_alloc(data, 16);
333 krb5_set_error_string(context, "out of memory");
336 memset(data->data, 0, data->length);
340 for (i = 0; i < p->pac->numbuffers; i++) {
341 size_t len = p->pac->buffers[i].buffersize;
342 size_t offset = p->pac->buffers[i].offset_lo;
344 if (p->pac->buffers[i].type != type)
347 ret = krb5_data_copy(data, (unsigned char *)p->data.data + offset, len);
349 krb5_set_error_string(context, "Out of memory");
354 krb5_set_error_string(context, "No PAC buffer of type %lu was found",
355 (unsigned long)type);
364 krb5_pac_get_types(krb5_context context,
371 *types = calloc(p->pac->numbuffers, sizeof(*types));
372 if (*types == NULL) {
374 krb5_set_error_string(context, "out of memory");
377 for (i = 0; i < p->pac->numbuffers; i++)
378 (*types)[i] = p->pac->buffers[i].type;
379 *len = p->pac->numbuffers;
389 krb5_pac_free(krb5_context context, krb5_pac pac)
391 krb5_data_free(&pac->data);
400 static krb5_error_code
401 verify_checksum(krb5_context context,
402 const struct PAC_INFO_BUFFER *sig,
403 const krb5_data *data,
404 void *ptr, size_t len,
405 const krb5_keyblock *key)
407 krb5_crypto crypto = NULL;
408 krb5_storage *sp = NULL;
413 memset(&cksum, 0, sizeof(cksum));
415 sp = krb5_storage_from_mem((char *)data->data + sig->offset_lo,
418 krb5_set_error_string(context, "out of memory");
421 krb5_storage_set_flags(sp, KRB5_STORAGE_BYTEORDER_LE);
423 CHECK(ret, krb5_ret_uint32(sp, &type), out);
424 cksum.cksumtype = type;
425 cksum.checksum.length =
426 sig->buffersize - krb5_storage_seek(sp, 0, SEEK_CUR);
427 cksum.checksum.data = malloc(cksum.checksum.length);
428 if (cksum.checksum.data == NULL) {
429 krb5_set_error_string(context, "out of memory");
433 ret = krb5_storage_read(sp, cksum.checksum.data, cksum.checksum.length);
434 if (ret != cksum.checksum.length) {
435 krb5_set_error_string(context, "PAC checksum missing checksum");
440 if (!krb5_checksum_is_keyed(context, cksum.cksumtype)) {
441 krb5_set_error_string (context, "Checksum type %d not keyed",
447 ret = krb5_crypto_init(context, key, 0, &crypto);
451 ret = krb5_verify_checksum(context, crypto, KRB5_KU_OTHER_CKSUM,
453 free(cksum.checksum.data);
454 krb5_crypto_destroy(context, crypto);
455 krb5_storage_free(sp);
460 if (cksum.checksum.data)
461 free(cksum.checksum.data);
463 krb5_storage_free(sp);
465 krb5_crypto_destroy(context, crypto);
469 static krb5_error_code
470 create_checksum(krb5_context context,
471 const krb5_keyblock *key,
472 void *data, size_t datalen,
473 void *sig, size_t siglen)
475 krb5_crypto crypto = NULL;
479 ret = krb5_crypto_init(context, key, 0, &crypto);
483 ret = krb5_create_checksum(context, crypto, KRB5_KU_OTHER_CKSUM, 0,
484 data, datalen, &cksum);
485 krb5_crypto_destroy(context, crypto);
489 if (cksum.checksum.length != siglen) {
490 krb5_set_error_string(context, "pac checksum wrong length");
491 free_Checksum(&cksum);
495 memcpy(sig, cksum.checksum.data, siglen);
496 free_Checksum(&cksum);
506 #define NTTIME_EPOCH 0x019DB1DED53E8000LL
509 unix2nttime(time_t unix_time)
512 wt = unix_time * (uint64_t)10000000 + (uint64_t)NTTIME_EPOCH;
516 static krb5_error_code
517 verify_logonname(krb5_context context,
518 const struct PAC_INFO_BUFFER *logon_name,
519 const krb5_data *data,
521 krb5_const_principal principal)
525 uint32_t time1, time2;
530 sp = krb5_storage_from_readonly_mem((const char *)data->data + logon_name->offset_lo,
531 logon_name->buffersize);
533 krb5_set_error_string(context, "Out of memory");
537 krb5_storage_set_flags(sp, KRB5_STORAGE_BYTEORDER_LE);
539 CHECK(ret, krb5_ret_uint32(sp, &time1), out);
540 CHECK(ret, krb5_ret_uint32(sp, &time2), out);
544 t1 = unix2nttime(authtime);
545 t2 = ((uint64_t)time2 << 32) | time1;
547 krb5_storage_free(sp);
548 krb5_set_error_string(context, "PAC timestamp mismatch");
552 CHECK(ret, krb5_ret_uint16(sp, &len), out);
554 krb5_storage_free(sp);
555 krb5_set_error_string(context, "PAC logon name length missing");
561 krb5_storage_free(sp);
562 krb5_set_error_string(context, "Out of memory");
565 ret = krb5_storage_read(sp, s, len);
567 krb5_storage_free(sp);
568 krb5_set_error_string(context, "Failed to read PAC logon name");
571 krb5_storage_free(sp);
573 size_t ucs2len = len / 2;
576 unsigned int flags = WIND_RW_LE;
578 ucs2 = malloc(sizeof(ucs2[0]) * ucs2len);
580 krb5_set_error_string(context, "malloc: out of memory");
583 ret = wind_ucs2read(s, len, &flags, ucs2, &ucs2len);
587 krb5_set_error_string(context, "Failed to convert string to UCS-2");
590 ret = wind_ucs2utf8_length(ucs2, ucs2len, &u8len);
593 krb5_set_error_string(context, "Failed to count length of UCS-2 string");
596 u8len += 1; /* Add space for NUL */
600 krb5_set_error_string(context, "malloc: out of memory");
603 ret = wind_ucs2utf8(ucs2, ucs2len, s, &u8len);
606 krb5_set_error_string(context, "Failed to convert to UTF-8");
610 ret = krb5_parse_name_flags(context, s, KRB5_PRINCIPAL_PARSE_NO_REALM, &p2);
615 if (krb5_principal_compare_any_realm(context, principal, p2) != TRUE) {
616 krb5_set_error_string(context, "PAC logon name mismatch");
619 krb5_free_principal(context, p2);
629 static krb5_error_code
630 build_logon_name(krb5_context context,
632 krb5_const_principal principal,
641 t = unix2nttime(authtime);
643 krb5_data_zero(logon);
645 sp = krb5_storage_emem();
647 krb5_set_error_string(context, "out of memory");
650 krb5_storage_set_flags(sp, KRB5_STORAGE_BYTEORDER_LE);
652 CHECK(ret, krb5_store_uint32(sp, t & 0xffffffff), out);
653 CHECK(ret, krb5_store_uint32(sp, t >> 32), out);
655 ret = krb5_unparse_name_flags(context, principal,
656 KRB5_PRINCIPAL_UNPARSE_NO_REALM, &s);
662 CHECK(ret, krb5_store_uint16(sp, len * 2), out);
664 #if 1 /* cheat for now */
665 s2 = malloc(len * 2);
671 for (i = 0; i < len; i++) {
677 /* write libwind code here */
680 ret = krb5_storage_write(sp, s2, len * 2);
682 if (ret != len * 2) {
686 ret = krb5_storage_to_data(sp, logon);
689 krb5_storage_free(sp);
693 krb5_storage_free(sp);
703 krb5_pac_verify(krb5_context context,
706 krb5_const_principal principal,
707 const krb5_keyblock *server,
708 const krb5_keyblock *privsvr)
712 if (pac->server_checksum == NULL) {
713 krb5_set_error_string(context, "PAC missing server checksum");
716 if (pac->privsvr_checksum == NULL) {
717 krb5_set_error_string(context, "PAC missing kdc checksum");
720 if (pac->logon_name == NULL) {
721 krb5_set_error_string(context, "PAC missing logon name");
725 ret = verify_logonname(context,
734 * in the service case, clean out data option of the privsvr and
735 * server checksum before checking the checksum.
740 ret = krb5_copy_data(context, &pac->data, ©);
744 if (pac->server_checksum->buffersize < 4)
746 if (pac->privsvr_checksum->buffersize < 4)
749 memset((char *)copy->data + pac->server_checksum->offset_lo + 4,
751 pac->server_checksum->buffersize - 4);
753 memset((char *)copy->data + pac->privsvr_checksum->offset_lo + 4,
755 pac->privsvr_checksum->buffersize - 4);
757 ret = verify_checksum(context,
758 pac->server_checksum,
763 krb5_free_data(context, copy);
768 ret = verify_checksum(context,
769 pac->privsvr_checksum,
771 (char *)pac->data.data
772 + pac->server_checksum->offset_lo + 4,
773 pac->server_checksum->buffersize - 4,
786 static krb5_error_code
787 fill_zeros(krb5_context context, krb5_storage *sp, size_t len)
794 if (l > sizeof(zeros))
796 sret = krb5_storage_write(sp, zeros, l);
798 krb5_set_error_string(context, "out of memory");
806 static krb5_error_code
807 pac_checksum(krb5_context context,
808 const krb5_keyblock *key,
812 krb5_cksumtype cktype;
814 krb5_crypto crypto = NULL;
816 ret = krb5_crypto_init(context, key, 0, &crypto);
820 ret = krb5_crypto_get_checksum_type(context, crypto, &cktype);
821 ret = krb5_crypto_destroy(context, crypto);
825 if (krb5_checksum_is_keyed(context, cktype) == FALSE) {
826 krb5_set_error_string(context, "PAC checksum type is not keyed");
830 ret = krb5_checksumsize(context, cktype, cksumsize);
834 *cksumtype = (uint32_t)cktype;
840 _krb5_pac_sign(krb5_context context,
843 krb5_principal principal,
844 const krb5_keyblock *server_key,
845 const krb5_keyblock *priv_key,
849 krb5_storage *sp = NULL, *spdata = NULL;
851 size_t server_size, priv_size;
852 uint32_t server_offset = 0, priv_offset = 0;
853 uint32_t server_cksumtype = 0, priv_cksumtype = 0;
857 krb5_data_zero(&logon);
859 if (p->logon_name == NULL)
861 if (p->server_checksum == NULL)
863 if (p->privsvr_checksum == NULL)
869 ptr = realloc(p->pac, sizeof(*p->pac) + (sizeof(p->pac->buffers[0]) * (p->pac->numbuffers + num - 1)));
871 krb5_set_error_string(context, "out of memory");
876 if (p->logon_name == NULL) {
877 p->logon_name = &p->pac->buffers[p->pac->numbuffers++];
878 memset(p->logon_name, 0, sizeof(*p->logon_name));
879 p->logon_name->type = PAC_LOGON_NAME;
881 if (p->server_checksum == NULL) {
882 p->server_checksum = &p->pac->buffers[p->pac->numbuffers++];
883 memset(p->server_checksum, 0, sizeof(*p->server_checksum));
884 p->server_checksum->type = PAC_SERVER_CHECKSUM;
886 if (p->privsvr_checksum == NULL) {
887 p->privsvr_checksum = &p->pac->buffers[p->pac->numbuffers++];
888 memset(p->privsvr_checksum, 0, sizeof(*p->privsvr_checksum));
889 p->privsvr_checksum->type = PAC_PRIVSVR_CHECKSUM;
893 /* Calculate LOGON NAME */
894 ret = build_logon_name(context, authtime, principal, &logon);
898 /* Set lengths for checksum */
899 ret = pac_checksum(context, server_key, &server_cksumtype, &server_size);
902 ret = pac_checksum(context, priv_key, &priv_cksumtype, &priv_size);
907 sp = krb5_storage_emem();
909 krb5_set_error_string(context, "out of memory");
912 krb5_storage_set_flags(sp, KRB5_STORAGE_BYTEORDER_LE);
914 spdata = krb5_storage_emem();
915 if (spdata == NULL) {
916 krb5_storage_free(sp);
917 krb5_set_error_string(context, "out of memory");
920 krb5_storage_set_flags(spdata, KRB5_STORAGE_BYTEORDER_LE);
922 CHECK(ret, krb5_store_uint32(sp, p->pac->numbuffers), out);
923 CHECK(ret, krb5_store_uint32(sp, p->pac->version), out);
925 end = PACTYPE_SIZE + (PAC_INFO_BUFFER_SIZE * p->pac->numbuffers);
927 for (i = 0; i < p->pac->numbuffers; i++) {
934 if (p->pac->buffers[i].type == PAC_SERVER_CHECKSUM) {
935 len = server_size + 4;
936 server_offset = end + 4;
937 CHECK(ret, krb5_store_uint32(spdata, server_cksumtype), out);
938 CHECK(ret, fill_zeros(context, spdata, server_size), out);
939 } else if (p->pac->buffers[i].type == PAC_PRIVSVR_CHECKSUM) {
941 priv_offset = end + 4;
942 CHECK(ret, krb5_store_uint32(spdata, priv_cksumtype), out);
943 CHECK(ret, fill_zeros(context, spdata, priv_size), out);
944 } else if (p->pac->buffers[i].type == PAC_LOGON_NAME) {
945 len = krb5_storage_write(spdata, logon.data, logon.length);
946 if (logon.length != len) {
951 len = p->pac->buffers[i].buffersize;
952 ptr = (char *)p->data.data + p->pac->buffers[i].offset_lo;
954 sret = krb5_storage_write(spdata, ptr, len);
956 krb5_set_error_string(context, "out of memory");
960 /* XXX if not aligned, fill_zeros */
964 CHECK(ret, krb5_store_uint32(sp, p->pac->buffers[i].type), out);
965 CHECK(ret, krb5_store_uint32(sp, len), out);
966 CHECK(ret, krb5_store_uint32(sp, end), out);
967 CHECK(ret, krb5_store_uint32(sp, 0), out);
969 /* advance data endpointer and align */
974 e = ((end + PAC_ALIGNMENT - 1) / PAC_ALIGNMENT) * PAC_ALIGNMENT;
976 CHECK(ret, fill_zeros(context, spdata, e - end), out);
983 /* assert (server_offset != 0 && priv_offset != 0); */
986 ret = krb5_storage_to_data(spdata, &d);
988 krb5_set_error_string(context, "out of memory");
991 ret = krb5_storage_write(sp, d.data, d.length);
992 if (ret != d.length) {
994 krb5_set_error_string(context, "out of memory");
1000 ret = krb5_storage_to_data(sp, &d);
1002 krb5_set_error_string(context, "out of memory");
1008 ret = create_checksum(context, server_key,
1010 (char *)d.data + server_offset, server_size);
1016 ret = create_checksum(context, priv_key,
1017 (char *)d.data + server_offset, server_size,
1018 (char *)d.data + priv_offset, priv_size);
1027 krb5_data_free(&logon);
1028 krb5_storage_free(sp);
1029 krb5_storage_free(spdata);
1033 krb5_data_free(&logon);
1035 krb5_storage_free(sp);
1037 krb5_storage_free(spdata);