// Copyright 2017 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // Package asn1 contains supporting types for parsing and building ASN.1 // messages with the cryptobyte package. package asn1 // import "golang.org/x/crypto/cryptobyte/asn1" // Tag represents an ASN.1 identifier octet, consisting of a tag number // (indicating a type) and class (such as context-specific or constructed). // // Methods in the cryptobyte package only support the low-tag-number form, i.e. // a single identifier octet with bits 7-8 encoding the class and bits 1-6 // encoding the tag number. type Tag uint8 const ( classConstructed = 0x20 classContextSpecific = 0x80 ) // Constructed returns t with the constructed class bit set. func (t Tag) Constructed() Tag { return t | classConstructed } // ContextSpecific returns t with the context-specific class bit set. func (t Tag) ContextSpecific() Tag { return t | classContextSpecific } // The following is a list of standard tag and class combinations. const ( BOOLEAN = Tag(1) INTEGER = Tag(2) BIT_STRING = Tag(3) OCTET_STRING = Tag(4) NULL = Tag(5) OBJECT_IDENTIFIER = Tag(6) ENUM = Tag(10) UTF8String = Tag(12) SEQUENCE = Tag(16 | classConstructed) SET = Tag(17 | classConstructed) PrintableString = Tag(19) T61String = Tag(20) IA5String = Tag(22) UTCTime = Tag(23) GeneralizedTime = Tag(24) GeneralString = Tag(27) )