47 lines
1.1 KiB
C
47 lines
1.1 KiB
C
// Copyright (c) 2015, Google Inc.
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// SPDX-License-Identifier: ISC
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#include <openssl/bn.h>
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#include <openssl/bytestring.h>
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#include <openssl/err.h>
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int BN_parse_asn1_unsigned(CBS *cbs, BIGNUM *ret) {
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CBS child;
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int is_negative;
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if (!CBS_get_asn1(cbs, &child, CBS_ASN1_INTEGER) ||
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!CBS_is_valid_asn1_integer(&child, &is_negative)) {
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OPENSSL_PUT_ERROR(BN, BN_R_BAD_ENCODING);
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return 0;
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}
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if (is_negative) {
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OPENSSL_PUT_ERROR(BN, BN_R_NEGATIVE_NUMBER);
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return 0;
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}
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return BN_bin2bn(CBS_data(&child), CBS_len(&child), ret) != NULL;
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}
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int BN_marshal_asn1(CBB *cbb, const BIGNUM *bn) {
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// Negative numbers are unsupported.
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if (BN_is_negative(bn)) {
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OPENSSL_PUT_ERROR(BN, BN_R_NEGATIVE_NUMBER);
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return 0;
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}
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CBB child;
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if (!CBB_add_asn1(cbb, &child, CBS_ASN1_INTEGER) ||
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// The number must be padded with a leading zero if the high bit would
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// otherwise be set or if |bn| is zero.
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(BN_num_bits(bn) % 8 == 0 && !CBB_add_u8(&child, 0x00)) ||
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!BN_bn2cbb_padded(&child, BN_num_bytes(bn), bn) ||
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!CBB_flush(cbb)) {
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OPENSSL_PUT_ERROR(BN, BN_R_ENCODE_ERROR);
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return 0;
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}
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return 1;
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}
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