tlv

Documentation

Overview

Package tlv implements various version (ASN.1 BER, Simple, Compact) TLV encoding using in ISO 7816-4.

Index

• Variables
• func EncodeBER(tvs ...TagValue) (buf []byte, err error)
• func EncodeCompact(tvs ...TagValue) (buf []byte, err error)
• func EncodeLengthBER(l int) ([]byte, error)
• func EncodeSimple(tvs ...TagValue) (buf []byte, err error)
• type Class
• type Tag
  • func NewBERTag(number uint, class Class) Tag
  • func (t Tag) BERNumber() uint
  • func (t Tag) Class() Class
  • func (t Tag) IsConstructed() bool
  • func (t Tag) MarshalBER() (buf []byte, err error)
  • func (t *Tag) UnmarshalBER(buf []byte) (rBuf []byte, err error)
• type TagValue
  • func New(t Tag, values ...any) (tv TagValue)
  • func (tv *TagValue) Append(value any)
  • func (tv TagValue) Equal(w TagValue) bool
  • func (tv TagValue) MarshalBER() (buf []byte, err error)
  • func (tv *TagValue) UnmarshalBER(buf []byte) ([]byte, error)
• type TagValues
  • func DecodeBER(buf []byte) (tvs TagValues, err error)
  • func DecodeCompact(buf []byte) (tvs TagValues, err error)
  • func DecodeSimple(buf []byte) (tvs TagValues, err error)
  • func (tvs *TagValues) DeleteAll(tag Tag) (removed int)
  • func (tvs TagValues) Equal(w TagValues) bool
  • func (tvs TagValues) Get(tag Tag) ([]byte, TagValues, bool)
  • func (tvs *TagValues) GetAll(tag Tag) (s TagValues)
  • func (tvs TagValues) GetChild(tag Tag, subs ...Tag) ([]byte, TagValues, bool)
  • func (tvs *TagValues) Pop(tag Tag) (TagValue, bool)
  • func (tvs *TagValues) PopAll(tag Tag) (s TagValues)
  • func (tvs *TagValues) Put(tv TagValue)

Variables

var (
	ErrInvalidTag   = errors.New("invalid tag")
	ErrTagToBig     = errors.New("tag is too big for this encoding")
	ErrValueToLarge = errors.New("valye to large for this encoding")
)

var ErrNotConstructed = errors.New("tag is not constructed but contains children")

Functions

func EncodeBER

func EncodeBER(tvs ...TagValue) (buf []byte, err error)

func EncodeCompact

func EncodeCompact(tvs ...TagValue) (buf []byte, err error)

func EncodeLengthBER

func EncodeLengthBER(l int) ([]byte, error)

func EncodeSimple

func EncodeSimple(tvs ...TagValue) (buf []byte, err error)

Types

type Class

type Class byte

const (
	ClassUniversal   Class = 0b00
	ClassApplication Class = 0b01
	ClassContext     Class = 0b10
	ClassPrivate     Class = 0b11
)

type Tag

type Tag uint // In theory ISO 7816-4 also supports 3-byte tags

func NewBERTag

func NewBERTag(number uint, class Class) Tag

NewBERTag creates a new ASN.1 BER-TLV encoded tag field from a value and class. See: ISO 7816-4 Section 5.2.2.1 BER-TLV tag fields

func (Tag) BERNumber

func (t Tag) BERNumber() uint

BERNumber returns the BER-encoded number of the tag.

func (Tag) Class

func (t Tag) Class() Class

Class returns the class of the tag.

func (Tag) IsConstructed

func (t Tag) IsConstructed() bool

IsConstructed returns true if the tag is constructed.

func (Tag) MarshalBER

func (t Tag) MarshalBER() (buf []byte, err error)

MarshalBER returns a BER-encoded representation of the tag.

func (*Tag) UnmarshalBER

func (t *Tag) UnmarshalBER(buf []byte) (rBuf []byte, err error)

UnmarshalBER decodes an ASN.1 BER-TLV encoded tag field. See: ISO 7816-4 Section 5.2.2.1 BER-TLV tag fields

type TagValue

type TagValue struct {
	Tag        Tag
	Value      []byte
	Children   TagValues
	SkipLength bool
}

func New

func New(t Tag, values ...any) (tv TagValue)

func (*TagValue) Append

func (tv *TagValue) Append(value any)

func (TagValue) Equal

func (tv TagValue) Equal(w TagValue) bool

func (TagValue) MarshalBER

func (tv TagValue) MarshalBER() (buf []byte, err error)

MarshalBER encodes an ASN.1 BER-TLV encoded tag field. See: ISO 7816-4 Section 5.2.2.1 BER-TLV tag fields

func (*TagValue) UnmarshalBER

func (tv *TagValue) UnmarshalBER(buf []byte) ([]byte, error)

type TagValues

type TagValues []TagValue

func DecodeBER

func DecodeBER(buf []byte) (tvs TagValues, err error)

func DecodeCompact

func DecodeCompact(buf []byte) (tvs TagValues, err error)

func DecodeSimple

func DecodeSimple(buf []byte) (tvs TagValues, err error)

func (*TagValues) DeleteAll

func (tvs *TagValues) DeleteAll(tag Tag) (removed int)

func (TagValues) Equal

func (tvs TagValues) Equal(w TagValues) bool

func (TagValues) Get

func (tvs TagValues) Get(tag Tag) ([]byte, TagValues, bool)

func (*TagValues) GetAll

func (tvs *TagValues) GetAll(tag Tag) (s TagValues)

func (TagValues) GetChild

func (tvs TagValues) GetChild(tag Tag, subs ...Tag) ([]byte, TagValues, bool)

func (*TagValues) Pop

func (tvs *TagValues) Pop(tag Tag) (TagValue, bool)

func (*TagValues) PopAll

func (tvs *TagValues) PopAll(tag Tag) (s TagValues)

func (*TagValues) Put

func (tvs *TagValues) Put(tv TagValue)