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/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ASN1_DECODER_H_
#define ASN1_DECODER_H_
#include <stddef.h>
#include <stdint.h>
class asn1_context {
public:
asn1_context(const uint8_t* buffer, size_t length) : p_(buffer), length_(length), app_type_(0) {}
int asn1_constructed_type() const;
asn1_context* asn1_constructed_get();
bool asn1_constructed_skip_all();
asn1_context* asn1_sequence_get();
asn1_context* asn1_set_get();
bool asn1_sequence_next();
bool asn1_oid_get(const uint8_t** oid, size_t* length);
bool asn1_octet_string_get(const uint8_t** octet_string, size_t* length);
private:
static constexpr int kMaskConstructed = 0xE0;
static constexpr int kMaskTag = 0x7F;
static constexpr int kMaskAppType = 0x1F;
static constexpr int kTagOctetString = 0x04;
static constexpr int kTagOid = 0x06;
static constexpr int kTagSequence = 0x30;
static constexpr int kTagSet = 0x31;
static constexpr int kTagConstructed = 0xA0;
int peek_byte() const;
int get_byte();
bool skip_bytes(size_t num_skip);
bool decode_length(size_t* out_len);
const uint8_t* p_;
size_t length_;
int app_type_;
};
#endif /* ASN1_DECODER_H_ */