golang asn1 代码
文件路径：/src/vendor/golang.org/x/crypto/cryptobyte/asn1/asn1.go
/ 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)
)