forked from go-webauthn/webauthn
/
base64.go
53 lines (41 loc) · 1.36 KB
/
base64.go
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package protocol
import (
"bytes"
"encoding/base64"
"reflect"
)
// URLEncodedBase64 represents a byte slice holding URL-encoded base64 data.
// When fields of this type are unmarshalled from JSON, the data is base64
// decoded into a byte slice.
type URLEncodedBase64 []byte
func (e URLEncodedBase64) String() string {
return base64.RawURLEncoding.EncodeToString(e)
}
// UnmarshalJSON base64 decodes a URL-encoded value, storing the result in the
// provided byte slice.
func (e *URLEncodedBase64) UnmarshalJSON(data []byte) error {
if bytes.Equal(data, []byte("null")) {
return nil
}
// TODO: Investigate this line. It is commented as trimming the leading spaces but appears to trim the leading and trailing double quotes instead.
// Trim the leading spaces.
data = bytes.Trim(data, "\"")
// Trim the trailing equal characters.
data = bytes.TrimRight(data, "=")
out := make([]byte, base64.RawURLEncoding.DecodedLen(len(data)))
n, err := base64.RawURLEncoding.Decode(out, data)
if err != nil {
return err
}
v := reflect.ValueOf(e).Elem()
v.SetBytes(out[:n])
return nil
}
// MarshalJSON base64 encodes a non URL-encoded value, storing the result in the
// provided byte slice.
func (e URLEncodedBase64) MarshalJSON() ([]byte, error) {
if e == nil {
return []byte("null"), nil
}
return []byte(`"` + base64.RawURLEncoding.EncodeToString(e) + `"`), nil
}