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// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef NET_DER_TAG_H_
#define NET_DER_TAG_H_
#include <stdint.h>
#include "net/base/net_export.h"
#include "third_party/boringssl/src/include/openssl/bytestring.h"
namespace net {
namespace der {
// This Tag type represents the identifier for an ASN.1 tag as encoded with
// DER. It matches the BoringSSL CBS and CBB in-memory representation for a
// tag.
// Callers must not assume it matches the DER representation for small tag
// numbers. Instead, constants are provided for universal class types, and
// functions are provided for building context specific tags. Tags can also be
// built from the provided constants and bitmasks.
using Tag = unsigned;
// Universal class primitive types
const Tag kBool = CBS_ASN1_BOOLEAN;
const Tag kInteger = CBS_ASN1_INTEGER;
const Tag kBitString = CBS_ASN1_BITSTRING;
const Tag kOctetString = CBS_ASN1_OCTETSTRING;
const Tag kNull = CBS_ASN1_NULL;
const Tag kOid = CBS_ASN1_OBJECT;
const Tag kEnumerated = CBS_ASN1_ENUMERATED;
const Tag kUtf8String = CBS_ASN1_UTF8STRING;
const Tag kPrintableString = CBS_ASN1_PRINTABLESTRING;
const Tag kTeletexString = CBS_ASN1_T61STRING;
const Tag kIA5String = CBS_ASN1_IA5STRING;
const Tag kUtcTime = CBS_ASN1_UTCTIME;
const Tag kGeneralizedTime = CBS_ASN1_GENERALIZEDTIME;
const Tag kUniversalString = CBS_ASN1_UNIVERSALSTRING;
const Tag kBmpString = CBS_ASN1_BMPSTRING;
// Universal class constructed types
const Tag kSequence = CBS_ASN1_SEQUENCE;
const Tag kSet = CBS_ASN1_SET;
// Primitive/constructed bits
const unsigned kTagPrimitive = 0x00;
const unsigned kTagConstructed = CBS_ASN1_CONSTRUCTED;
// Tag classes
const unsigned kTagUniversal = 0x00;
const unsigned kTagApplication = CBS_ASN1_APPLICATION;
const unsigned kTagContextSpecific = CBS_ASN1_CONTEXT_SPECIFIC;
const unsigned kTagPrivate = CBS_ASN1_PRIVATE;
// Masks for the 3 components of a tag (class, primitive/constructed, number)
const unsigned kTagNumberMask = CBS_ASN1_TAG_NUMBER_MASK;
const unsigned kTagConstructionMask = CBS_ASN1_CONSTRUCTED;
const unsigned kTagClassMask = CBS_ASN1_CLASS_MASK;
// Creates the value for the outer tag of an explicitly tagged type.
// The ASN.1 keyword for this is:
// [tag_number] EXPLICIT
// (Note, the EXPLICIT may be omitted if the entire schema is in
// EXPLICIT mode, the default)
NET_EXPORT Tag ContextSpecificConstructed(uint8_t tag_number);
NET_EXPORT Tag ContextSpecificPrimitive(uint8_t base);
NET_EXPORT bool IsConstructed(Tag tag);
} // namespace der
} // namespace net
#endif // NET_DER_TAG_H_