Package base32


Package base32 implements base32 encoding as specified by RFC 4648.


Package files



const (
    StdPadding rune = '=' // Standard padding character
    NoPadding  rune = -1  // No padding


HexEncoding is the “Extended Hex Alphabet” defined in RFC 4648. It is typically used in DNS.

var HexEncoding = NewEncoding(encodeHex)

StdEncoding is the standard base32 encoding, as defined in RFC 4648.

var StdEncoding = NewEncoding(encodeStd)

func NewDecoderSource

func NewDecoder(enc *Encoding, r io.Reader) io.Reader

NewDecoder constructs a new base32 stream decoder.

func NewEncoderSource

func NewEncoder(enc *Encoding, w io.Writer) io.WriteCloser

NewEncoder returns a new base32 stream encoder. Data written to the returned writer will be encoded using enc and then written to w. Base32 encodings operate in 5-byte blocks; when finished writing, the caller must Close the returned encoder to flush any partially written blocks.


package main

import (

func main() {
	input := []byte("foo\x00bar")
	encoder := base32.NewEncoder(base32.StdEncoding, os.Stdout)
	// Must close the encoder when finished to flush any partial blocks.
	// If you comment out the following line, the last partial block "r"
	// won't be encoded.

type CorruptInputErrorSource

type CorruptInputError int64

func (CorruptInputError) ErrorSource

func (e CorruptInputError) Error() string

type EncodingSource

An Encoding is a radix 32 encoding/decoding scheme, defined by a 32-character alphabet. The most common is the "base32" encoding introduced for SASL GSSAPI and standardized in RFC 4648. The alternate "base32hex" encoding is used in DNSSEC.

type Encoding struct {
    // contains filtered or unexported fields

func NewEncodingSource

func NewEncoding(encoder string) *Encoding

NewEncoding returns a new Encoding defined by the given alphabet, which must be a 32-byte string.

func (*Encoding) DecodeSource

func (enc *Encoding) Decode(dst, src []byte) (n int, err error)

Decode decodes src using the encoding enc. It writes at most DecodedLen(len(src)) bytes to dst and returns the number of bytes written. If src contains invalid base32 data, it will return the number of bytes successfully written and CorruptInputError. New line characters (\r and \n) are ignored.

func (*Encoding) DecodeStringSource

func (enc *Encoding) DecodeString(s string) ([]byte, error)

DecodeString returns the bytes represented by the base32 string s.


package main

import (

func main() {
	data, err := base32.StdEncoding.DecodeString(str)
	if err != nil {
		fmt.Println("error:", err)
	fmt.Printf("%q\n", data)

func (*Encoding) DecodedLenSource

func (enc *Encoding) DecodedLen(n int) int

DecodedLen returns the maximum length in bytes of the decoded data corresponding to n bytes of base32-encoded data.

func (*Encoding) EncodeSource

func (enc *Encoding) Encode(dst, src []byte)

Encode encodes src using the encoding enc, writing EncodedLen(len(src)) bytes to dst.

The encoding pads the output to a multiple of 8 bytes, so Encode is not appropriate for use on individual blocks of a large data stream. Use NewEncoder() instead.

func (*Encoding) EncodeToStringSource

func (enc *Encoding) EncodeToString(src []byte) string

EncodeToString returns the base32 encoding of src.


package main

import (

func main() {
	data := []byte("any + old & data")
	str := base32.StdEncoding.EncodeToString(data)

func (*Encoding) EncodedLenSource

func (enc *Encoding) EncodedLen(n int) int

EncodedLen returns the length in bytes of the base32 encoding of an input buffer of length n.

func (Encoding) WithPaddingSource 1.9

func (enc Encoding) WithPadding(padding rune) *Encoding

WithPadding creates a new encoding identical to enc except with a specified padding character, or NoPadding to disable padding. The padding character must not be '\r' or '\n', must not be contained in the encoding's alphabet and must be a rune equal or below '\xff'.

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Licensed under the Creative Commons Attribution License 3.0.