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Kenny Root7a4adb52013-10-09 10:14:35 -07001/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
Kenny Root7a4adb52013-10-09 10:14:35 -070017#ifndef ASN1_DECODER_H_
18#define ASN1_DECODER_H_
19
20#include <stdint.h>
21
Tao Bao861c53c2017-03-20 17:09:13 -070022class asn1_context {
23 public:
24 asn1_context(const uint8_t* buffer, size_t length) : p_(buffer), length_(length), app_type_(0) {}
25 int asn1_constructed_type() const;
26 asn1_context* asn1_constructed_get();
27 bool asn1_constructed_skip_all();
28 asn1_context* asn1_sequence_get();
29 asn1_context* asn1_set_get();
30 bool asn1_sequence_next();
31 bool asn1_oid_get(const uint8_t** oid, size_t* length);
32 bool asn1_octet_string_get(const uint8_t** octet_string, size_t* length);
Kenny Root7a4adb52013-10-09 10:14:35 -070033
Tao Bao861c53c2017-03-20 17:09:13 -070034 private:
35 static constexpr int kMaskConstructed = 0xE0;
36 static constexpr int kMaskTag = 0x7F;
37 static constexpr int kMaskAppType = 0x1F;
38
39 static constexpr int kTagOctetString = 0x04;
40 static constexpr int kTagOid = 0x06;
41 static constexpr int kTagSequence = 0x30;
42 static constexpr int kTagSet = 0x31;
43 static constexpr int kTagConstructed = 0xA0;
44
45 int peek_byte() const;
46 int get_byte();
47 bool skip_bytes(size_t num_skip);
48 bool decode_length(size_t* out_len);
49
50 const uint8_t* p_;
51 size_t length_;
52 int app_type_;
53};
Kenny Root7a4adb52013-10-09 10:14:35 -070054
55#endif /* ASN1_DECODER_H_ */