bertlv

README

BER-TLV

Go implementation of the BER TLV encoding that is widely used in APDU requests and responses.

Documentation

Index

• Variables
• func EncodeInt(in int) []byte
• func ReadLen(r io.Reader) (length int, n int, err error)
• func ReadTag(r io.Reader) (tag int, n int, err error)
• type TagValue
  • func Decode(p []byte) ([]TagValue, error)
  • func Find(tag int, p []byte) (*TagValue, error)
  • func (tv TagValue) Bytes() []byte
  • func (tv TagValue) IsConstructed() bool
  • func (tv TagValue) Len() []byte
  • func (tv TagValue) MarshalJSON() ([]byte, error)
  • func (tv *TagValue) ReadFrom(r io.Reader) (n int64, err error)
  • func (tv TagValue) String() string
  • func (tv TagValue) Tag() []byte
  • func (tv TagValue) WriteTo(w io.Writer) (n int64, err error)

Variables

var ErrNotFound = errors.New("not found")

ErrNotFound is returned when requested tag is not present in TLV structure

Functions

func EncodeInt

func EncodeInt(in int) []byte

EncodeInt encodes an integer to BER format.

func ReadLen

func ReadLen(r io.Reader) (length int, n int, err error)

ReadLen reads length of a tag and return it along with length of a length in bytes and/or an error

func ReadTag

func ReadTag(r io.Reader) (tag int, n int, err error)

ReadTag reads length of a tag and return it along with length of a length in bytes or an error

Types

type TagValue

type TagValue struct {
	T int
	V []byte
}

TagValue pair

func Decode

func Decode(p []byte) ([]TagValue, error)

Decode decodes TLV encoded byte slice into slice of TagValue structs

func Find

func Find(tag int, p []byte) (*TagValue, error)

Find finds first tag (DFS) in the TLV structure represented by p

func (TagValue) Bytes

func (tv TagValue) Bytes() []byte

Bytes encodes TagValue into a byte slice

func (TagValue) IsConstructed

func (tv TagValue) IsConstructed() bool

IsConstructed returns true if the value is constructed type(contains other TLV records)

func (TagValue) Len

func (tv TagValue) Len() []byte

Len returns encoded length of the value

func (TagValue) MarshalJSON

func (tv TagValue) MarshalJSON() ([]byte, error)

MarshalJSON implements json.Marshaller

func (*TagValue) ReadFrom

func (tv *TagValue) ReadFrom(r io.Reader) (n int64, err error)

ReadFrom implements io.ReaderFrom

func (TagValue) String

func (tv TagValue) String() string

func (TagValue) Tag

func (tv TagValue) Tag() []byte

Tag returns encoded tag value (two bytes tags are supported)

func (TagValue) WriteTo

func (tv TagValue) WriteTo(w io.Writer) (n int64, err error)

WriteTo implements io.WriterTo