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- /* Copyright (c) 2015, Google Inc.
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
- * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
- * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
-
- #include <openssl/bn.h>
-
- #include <openssl/bytestring.h>
- #include <openssl/err.h>
-
-
- int BN_parse_asn1_unsigned(CBS *cbs, BIGNUM *ret) {
- CBS child;
- if (!CBS_get_asn1(cbs, &child, CBS_ASN1_INTEGER) ||
- CBS_len(&child) == 0) {
- OPENSSL_PUT_ERROR(BN, BN_R_BAD_ENCODING);
- return 0;
- }
-
- if (CBS_data(&child)[0] & 0x80) {
- OPENSSL_PUT_ERROR(BN, BN_R_NEGATIVE_NUMBER);
- return 0;
- }
-
- // INTEGERs must be minimal.
- if (CBS_data(&child)[0] == 0x00 &&
- CBS_len(&child) > 1 &&
- !(CBS_data(&child)[1] & 0x80)) {
- OPENSSL_PUT_ERROR(BN, BN_R_BAD_ENCODING);
- return 0;
- }
-
- return BN_bin2bn(CBS_data(&child), CBS_len(&child), ret) != NULL;
- }
-
- int BN_marshal_asn1(CBB *cbb, const BIGNUM *bn) {
- // Negative numbers are unsupported.
- if (BN_is_negative(bn)) {
- OPENSSL_PUT_ERROR(BN, BN_R_NEGATIVE_NUMBER);
- return 0;
- }
-
- CBB child;
- if (!CBB_add_asn1(cbb, &child, CBS_ASN1_INTEGER) ||
- // The number must be padded with a leading zero if the high bit would
- // otherwise be set or if |bn| is zero.
- (BN_num_bits(bn) % 8 == 0 && !CBB_add_u8(&child, 0x00)) ||
- !BN_bn2cbb_padded(&child, BN_num_bytes(bn), bn) ||
- !CBB_flush(cbb)) {
- OPENSSL_PUT_ERROR(BN, BN_R_ENCODE_ERROR);
- return 0;
- }
-
- return 1;
- }
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