2 Unix SMB/CIFS implementation.
4 Copyright (C) Andrew Tridgell 2001
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #include "libcli/util/asn_1.h"
23 /* allocate an asn1 structure */
24 struct asn1_data *asn1_init(TALLOC_CTX *mem_ctx)
26 struct asn1_data *ret = talloc_zero(mem_ctx, struct asn1_data);
28 DEBUG(0,("asn1_init failed! out of memory\n"));
33 /* free an asn1 structure */
34 void asn1_free(struct asn1_data *data)
39 /* write to the ASN1 buffer, advancing the buffer pointer */
40 bool asn1_write(struct asn1_data *data, const void *p, int len)
42 if (data->has_error) return false;
43 if (data->length < data->ofs+len) {
45 newp = talloc_realloc(data, data->data, uint8_t, data->ofs+len);
48 data->has_error = true;
52 data->length = data->ofs+len;
54 memcpy(data->data + data->ofs, p, len);
59 /* useful fn for writing a uint8_t */
60 bool asn1_write_uint8(struct asn1_data *data, uint8_t v)
62 return asn1_write(data, &v, 1);
65 /* push a tag onto the asn1 data buffer. Used for nested structures */
66 bool asn1_push_tag(struct asn1_data *data, uint8_t tag)
68 struct nesting *nesting;
70 asn1_write_uint8(data, tag);
71 nesting = talloc(data, struct nesting);
73 data->has_error = true;
77 nesting->start = data->ofs;
78 nesting->next = data->nesting;
79 data->nesting = nesting;
80 return asn1_write_uint8(data, 0xff);
84 bool asn1_pop_tag(struct asn1_data *data)
86 struct nesting *nesting;
89 nesting = data->nesting;
92 data->has_error = true;
95 len = data->ofs - (nesting->start+1);
96 /* yes, this is ugly. We don't know in advance how many bytes the length
97 of a tag will take, so we assumed 1 byte. If we were wrong then we
98 need to correct our mistake */
100 data->data[nesting->start] = 0x84;
101 if (!asn1_write_uint8(data, 0)) return false;
102 if (!asn1_write_uint8(data, 0)) return false;
103 if (!asn1_write_uint8(data, 0)) return false;
104 if (!asn1_write_uint8(data, 0)) return false;
105 memmove(data->data+nesting->start+5, data->data+nesting->start+1, len);
106 data->data[nesting->start+1] = (len>>24) & 0xFF;
107 data->data[nesting->start+2] = (len>>16) & 0xFF;
108 data->data[nesting->start+3] = (len>>8) & 0xFF;
109 data->data[nesting->start+4] = len&0xff;
110 } else if (len > 0xFFFF) {
111 data->data[nesting->start] = 0x83;
112 if (!asn1_write_uint8(data, 0)) return false;
113 if (!asn1_write_uint8(data, 0)) return false;
114 if (!asn1_write_uint8(data, 0)) return false;
115 memmove(data->data+nesting->start+4, data->data+nesting->start+1, len);
116 data->data[nesting->start+1] = (len>>16) & 0xFF;
117 data->data[nesting->start+2] = (len>>8) & 0xFF;
118 data->data[nesting->start+3] = len&0xff;
119 } else if (len > 255) {
120 data->data[nesting->start] = 0x82;
121 if (!asn1_write_uint8(data, 0)) return false;
122 if (!asn1_write_uint8(data, 0)) return false;
123 memmove(data->data+nesting->start+3, data->data+nesting->start+1, len);
124 data->data[nesting->start+1] = len>>8;
125 data->data[nesting->start+2] = len&0xff;
126 } else if (len > 127) {
127 data->data[nesting->start] = 0x81;
128 if (!asn1_write_uint8(data, 0)) return false;
129 memmove(data->data+nesting->start+2, data->data+nesting->start+1, len);
130 data->data[nesting->start+1] = len;
132 data->data[nesting->start] = len;
135 data->nesting = nesting->next;
136 talloc_free(nesting);
140 /* "i" is the one's complement representation, as is the normal result of an
141 * implicit signed->unsigned conversion */
143 static bool push_int_bigendian(struct asn1_data *data, unsigned int i, bool negative)
145 uint8_t lowest = i & 0xFF;
149 if (!push_int_bigendian(data, i, negative))
152 if (data->nesting->start+1 == data->ofs) {
154 /* We did not write anything yet, looking at the highest
158 /* Don't write leading 0xff's */
162 if ((lowest & 0x80) == 0) {
163 /* The only exception for a leading 0xff is if
164 * the highest bit is 0, which would indicate
165 * a positive value */
166 if (!asn1_write_uint8(data, 0xff))
171 /* The highest bit of a positive integer is 1,
172 * this would indicate a negative number. Push
173 * a 0 to indicate a positive one */
174 if (!asn1_write_uint8(data, 0))
180 return asn1_write_uint8(data, lowest);
183 /* write an Integer without the tag framing. Needed for example for the LDAP
184 * Abandon Operation */
186 bool asn1_write_implicit_Integer(struct asn1_data *data, int i)
189 /* -1 is special as it consists of all-0xff bytes. In
190 push_int_bigendian this is the only case that is not
191 properly handled, as all 0xff bytes would be handled as
192 leading ones to be ignored. */
193 return asn1_write_uint8(data, 0xff);
195 return push_int_bigendian(data, i, i<0);
200 /* write an integer */
201 bool asn1_write_Integer(struct asn1_data *data, int i)
203 if (!asn1_push_tag(data, ASN1_INTEGER)) return false;
204 if (!asn1_write_implicit_Integer(data, i)) return false;
205 return asn1_pop_tag(data);
208 bool ber_write_OID_String(DATA_BLOB *blob, const char *OID)
211 const char *p = (const char *)OID;
215 v = strtoul(p, &newp, 10);
216 if (newp[0] != '.') return false;
219 v2 = strtoul(p, &newp, 10);
220 if (newp[0] != '.') return false;
223 /*the ber representation can't use more space then the string one */
224 *blob = data_blob(NULL, strlen(OID));
225 if (!blob->data) return false;
227 blob->data[0] = 40*v + v2;
231 v = strtoul(p, &newp, 10);
232 if (newp[0] == '.') {
234 } else if (newp[0] == '\0') {
237 data_blob_free(blob);
240 if (v >= (1<<28)) blob->data[i++] = (0x80 | ((v>>28)&0x7f));
241 if (v >= (1<<21)) blob->data[i++] = (0x80 | ((v>>21)&0x7f));
242 if (v >= (1<<14)) blob->data[i++] = (0x80 | ((v>>14)&0x7f));
243 if (v >= (1<<7)) blob->data[i++] = (0x80 | ((v>>7)&0x7f));
244 blob->data[i++] = (v&0x7f);
252 /* write an object ID to a ASN1 buffer */
253 bool asn1_write_OID(struct asn1_data *data, const char *OID)
257 if (!asn1_push_tag(data, ASN1_OID)) return false;
259 if (!ber_write_OID_String(&blob, OID)) {
260 data->has_error = true;
264 if (!asn1_write(data, blob.data, blob.length)) {
265 data->has_error = true;
268 data_blob_free(&blob);
269 return asn1_pop_tag(data);
272 /* write an octet string */
273 bool asn1_write_OctetString(struct asn1_data *data, const void *p, size_t length)
275 asn1_push_tag(data, ASN1_OCTET_STRING);
276 asn1_write(data, p, length);
278 return !data->has_error;
281 /* write a LDAP string */
282 bool asn1_write_LDAPString(struct asn1_data *data, const char *s)
284 asn1_write(data, s, strlen(s));
285 return !data->has_error;
288 /* write a general string */
289 bool asn1_write_GeneralString(struct asn1_data *data, const char *s)
291 asn1_push_tag(data, ASN1_GENERAL_STRING);
292 asn1_write_LDAPString(data, s);
294 return !data->has_error;
297 bool asn1_write_ContextSimple(struct asn1_data *data, uint8_t num, DATA_BLOB *blob)
299 asn1_push_tag(data, ASN1_CONTEXT_SIMPLE(num));
300 asn1_write(data, blob->data, blob->length);
302 return !data->has_error;
305 /* write a BOOLEAN */
306 bool asn1_write_BOOLEAN(struct asn1_data *data, bool v)
308 asn1_push_tag(data, ASN1_BOOLEAN);
309 asn1_write_uint8(data, v ? 0xFF : 0);
311 return !data->has_error;
314 bool asn1_read_BOOLEAN(struct asn1_data *data, bool *v)
317 asn1_start_tag(data, ASN1_BOOLEAN);
318 asn1_read_uint8(data, &tmp);
325 return !data->has_error;
328 /* check a BOOLEAN */
329 bool asn1_check_BOOLEAN(struct asn1_data *data, bool v)
333 asn1_read_uint8(data, &b);
334 if (b != ASN1_BOOLEAN) {
335 data->has_error = true;
338 asn1_read_uint8(data, &b);
340 data->has_error = true;
343 return !data->has_error;
347 /* load a struct asn1_data structure with a lump of data, ready to be parsed */
348 bool asn1_load(struct asn1_data *data, DATA_BLOB blob)
351 data->data = talloc_memdup(data, blob.data, blob.length);
353 data->has_error = true;
356 data->length = blob.length;
360 /* Peek into an ASN1 buffer, not advancing the pointer */
361 bool asn1_peek(struct asn1_data *data, void *p, int len)
366 if (len < 0 || data->ofs + len < data->ofs || data->ofs + len < len)
369 if (data->ofs + len > data->length) {
370 /* we need to mark the buffer as consumed, so the caller knows
371 this was an out of data error, and not a decode error */
372 data->ofs = data->length;
376 memcpy(p, data->data + data->ofs, len);
380 /* read from a ASN1 buffer, advancing the buffer pointer */
381 bool asn1_read(struct asn1_data *data, void *p, int len)
383 if (!asn1_peek(data, p, len)) {
384 data->has_error = true;
392 /* read a uint8_t from a ASN1 buffer */
393 bool asn1_read_uint8(struct asn1_data *data, uint8_t *v)
395 return asn1_read(data, v, 1);
398 bool asn1_peek_uint8(struct asn1_data *data, uint8_t *v)
400 return asn1_peek(data, v, 1);
403 bool asn1_peek_tag(struct asn1_data *data, uint8_t tag)
407 if (asn1_tag_remaining(data) <= 0) {
411 if (!asn1_peek_uint8(data, &b))
417 /* start reading a nested asn1 structure */
418 bool asn1_start_tag(struct asn1_data *data, uint8_t tag)
421 struct nesting *nesting;
423 if (!asn1_read_uint8(data, &b))
427 data->has_error = true;
430 nesting = talloc(data, struct nesting);
432 data->has_error = true;
436 if (!asn1_read_uint8(data, &b)) {
442 if (!asn1_read_uint8(data, &b))
446 if (!asn1_read_uint8(data, &b))
448 nesting->taglen = (nesting->taglen << 8) | b;
454 nesting->start = data->ofs;
455 nesting->next = data->nesting;
456 data->nesting = nesting;
457 if (asn1_tag_remaining(data) == -1) {
460 return !data->has_error;
463 /* stop reading a tag */
464 bool asn1_end_tag(struct asn1_data *data)
466 struct nesting *nesting;
468 /* make sure we read it all */
469 if (asn1_tag_remaining(data) != 0) {
470 data->has_error = true;
474 nesting = data->nesting;
477 data->has_error = true;
481 data->nesting = nesting->next;
482 talloc_free(nesting);
486 /* work out how many bytes are left in this nested tag */
487 int asn1_tag_remaining(struct asn1_data *data)
490 if (data->has_error) {
494 if (!data->nesting) {
495 data->has_error = true;
498 remaining = data->nesting->taglen - (data->ofs - data->nesting->start);
499 if (remaining > (data->length - data->ofs)) {
500 data->has_error = true;
506 /* read an object ID from a data blob */
507 bool ber_read_OID_String(TALLOC_CTX *mem_ctx, DATA_BLOB blob, const char **OID)
512 char *tmp_oid = NULL;
514 if (blob.length < 2) return false;
518 tmp_oid = talloc_asprintf(mem_ctx, "%u", b[0]/40);
519 if (!tmp_oid) goto nomem;
520 tmp_oid = talloc_asprintf_append_buffer(tmp_oid, ".%u", b[0]%40);
521 if (!tmp_oid) goto nomem;
523 for(i = 1, v = 0; i < blob.length; i++) {
524 v = (v<<7) | (b[i]&0x7f);
525 if ( ! (b[i] & 0x80)) {
526 tmp_oid = talloc_asprintf_append_buffer(tmp_oid, ".%u", v);
529 if (!tmp_oid) goto nomem;
533 talloc_free(tmp_oid);
544 /* read an object ID from a ASN1 buffer */
545 bool asn1_read_OID(struct asn1_data *data, TALLOC_CTX *mem_ctx, const char **OID)
550 if (!asn1_start_tag(data, ASN1_OID)) return false;
552 len = asn1_tag_remaining(data);
554 data->has_error = true;
558 blob = data_blob(NULL, len);
560 data->has_error = true;
564 asn1_read(data, blob.data, len);
566 if (data->has_error) {
567 data_blob_free(&blob);
571 if (!ber_read_OID_String(mem_ctx, blob, OID)) {
572 data->has_error = true;
573 data_blob_free(&blob);
577 data_blob_free(&blob);
581 /* check that the next object ID is correct */
582 bool asn1_check_OID(struct asn1_data *data, const char *OID)
586 if (!asn1_read_OID(data, data, &id)) return false;
588 if (strcmp(id, OID) != 0) {
589 talloc_free(discard_const(id));
590 data->has_error = true;
593 talloc_free(discard_const(id));
597 /* read a LDAPString from a ASN1 buffer */
598 bool asn1_read_LDAPString(struct asn1_data *data, TALLOC_CTX *mem_ctx, char **s)
601 len = asn1_tag_remaining(data);
603 data->has_error = true;
606 *s = talloc_array(mem_ctx, char, len+1);
608 data->has_error = true;
611 asn1_read(data, *s, len);
613 return !data->has_error;
617 /* read a GeneralString from a ASN1 buffer */
618 bool asn1_read_GeneralString(struct asn1_data *data, TALLOC_CTX *mem_ctx, char **s)
620 if (!asn1_start_tag(data, ASN1_GENERAL_STRING)) return false;
621 if (!asn1_read_LDAPString(data, mem_ctx, s)) return false;
622 return asn1_end_tag(data);
626 /* read a octet string blob */
627 bool asn1_read_OctetString(struct asn1_data *data, TALLOC_CTX *mem_ctx, DATA_BLOB *blob)
631 if (!asn1_start_tag(data, ASN1_OCTET_STRING)) return false;
632 len = asn1_tag_remaining(data);
634 data->has_error = true;
637 *blob = data_blob_talloc(mem_ctx, NULL, len+1);
639 data->has_error = true;
642 asn1_read(data, blob->data, len);
647 if (data->has_error) {
648 data_blob_free(blob);
649 *blob = data_blob(NULL, 0);
655 bool asn1_read_ContextSimple(struct asn1_data *data, uint8_t num, DATA_BLOB *blob)
659 if (!asn1_start_tag(data, ASN1_CONTEXT_SIMPLE(num))) return false;
660 len = asn1_tag_remaining(data);
662 data->has_error = true;
665 *blob = data_blob(NULL, len);
666 if ((len != 0) && (!blob->data)) {
667 data->has_error = true;
670 asn1_read(data, blob->data, len);
672 return !data->has_error;
675 /* read an interger without tag*/
676 bool asn1_read_implicit_Integer(struct asn1_data *data, int *i)
681 while (!data->has_error && asn1_tag_remaining(data)>0) {
682 if (!asn1_read_uint8(data, &b)) return false;
685 return !data->has_error;
689 /* read an interger */
690 bool asn1_read_Integer(struct asn1_data *data, int *i)
694 if (!asn1_start_tag(data, ASN1_INTEGER)) return false;
695 if (!asn1_read_implicit_Integer(data, i)) return false;
696 return asn1_end_tag(data);
699 /* read an interger */
700 bool asn1_read_enumerated(struct asn1_data *data, int *v)
704 if (!asn1_start_tag(data, ASN1_ENUMERATED)) return false;
705 while (!data->has_error && asn1_tag_remaining(data)>0) {
707 asn1_read_uint8(data, &b);
710 return asn1_end_tag(data);
713 /* check a enumarted value is correct */
714 bool asn1_check_enumerated(struct asn1_data *data, int v)
717 if (!asn1_start_tag(data, ASN1_ENUMERATED)) return false;
718 asn1_read_uint8(data, &b);
722 data->has_error = false;
724 return !data->has_error;
727 /* write an enumarted value to the stream */
728 bool asn1_write_enumerated(struct asn1_data *data, uint8_t v)
730 if (!asn1_push_tag(data, ASN1_ENUMERATED)) return false;
731 asn1_write_uint8(data, v);
733 return !data->has_error;
737 check if a ASN.1 blob is a full tag
739 NTSTATUS asn1_full_tag(DATA_BLOB blob, uint8_t tag, size_t *packet_size)
741 struct asn1_data *asn1 = asn1_init(NULL);
744 NT_STATUS_HAVE_NO_MEMORY(asn1);
746 asn1->data = blob.data;
747 asn1->length = blob.length;
748 asn1_start_tag(asn1, tag);
749 if (asn1->has_error) {
751 return STATUS_MORE_ENTRIES;
753 size = asn1_tag_remaining(asn1) + asn1->ofs;
757 if (size > blob.length) {
758 return STATUS_MORE_ENTRIES;