Encode/Decode base64

Issue

here is my code and i don’t understand why the decode function doesn’t work.

Little insight would be great please.

func EncodeB64(message string) (retour string) {
    base64Text := make([]byte, base64.StdEncoding.EncodedLen(len(message)))
    base64.StdEncoding.Encode(base64Text, []byte(message))
    return string(base64Text)
}

func DecodeB64(message string) (retour string) {
    base64Text := make([]byte, base64.StdEncoding.DecodedLen(len(message)))
    base64.StdEncoding.Decode(base64Text, []byte(message))
    fmt.Printf("base64: %s\n", base64Text)
    return string(base64Text)
}

It gaves me :
[Decode error – output not utf-8][Decode error – output not utf-8]

Solution

DecodedLen returns the maximal length.

This length is useful for sizing your buffer but part of the buffer won’t be written and thus won’t be valid UTF-8.

You have to use only the real written length returned by the Decode function.

l, _ := base64.StdEncoding.Decode(base64Text, []byte(message))
log.Printf("base64: %s\n", base64Text[:l])

Answered By – Denys Séguret

Answer Checked By – Willingham (GoLangFix Volunteer)