mirror of https://github.com/bjdgyc/anylink.git
63 lines
1.6 KiB
Go
63 lines
1.6 KiB
Go
package extension
|
|
|
|
import (
|
|
"encoding/binary"
|
|
|
|
"github.com/pion/dtls/v2/pkg/crypto/elliptic"
|
|
)
|
|
|
|
const (
|
|
supportedPointFormatsSize = 5
|
|
)
|
|
|
|
// SupportedPointFormats allows a Client/Server to negotiate
|
|
// the EllipticCurvePointFormats
|
|
//
|
|
// https://tools.ietf.org/html/rfc4492#section-5.1.2
|
|
type SupportedPointFormats struct {
|
|
PointFormats []elliptic.CurvePointFormat
|
|
}
|
|
|
|
// TypeValue returns the extension TypeValue
|
|
func (s SupportedPointFormats) TypeValue() TypeValue {
|
|
return SupportedPointFormatsTypeValue
|
|
}
|
|
|
|
// Marshal encodes the extension
|
|
func (s *SupportedPointFormats) Marshal() ([]byte, error) {
|
|
out := make([]byte, supportedPointFormatsSize)
|
|
|
|
binary.BigEndian.PutUint16(out, uint16(s.TypeValue()))
|
|
binary.BigEndian.PutUint16(out[2:], uint16(1+(len(s.PointFormats))))
|
|
out[4] = byte(len(s.PointFormats))
|
|
|
|
for _, v := range s.PointFormats {
|
|
out = append(out, byte(v))
|
|
}
|
|
return out, nil
|
|
}
|
|
|
|
// Unmarshal populates the extension from encoded data
|
|
func (s *SupportedPointFormats) Unmarshal(data []byte) error {
|
|
if len(data) <= supportedPointFormatsSize {
|
|
return errBufferTooSmall
|
|
} else if TypeValue(binary.BigEndian.Uint16(data)) != s.TypeValue() {
|
|
return errInvalidExtensionType
|
|
}
|
|
|
|
pointFormatCount := int(binary.BigEndian.Uint16(data[4:]))
|
|
if supportedGroupsHeaderSize+(pointFormatCount) > len(data) {
|
|
return errLengthMismatch
|
|
}
|
|
|
|
for i := 0; i < pointFormatCount; i++ {
|
|
p := elliptic.CurvePointFormat(data[supportedPointFormatsSize+i])
|
|
switch p {
|
|
case elliptic.CurvePointFormatUncompressed:
|
|
s.PointFormats = append(s.PointFormats, p)
|
|
default:
|
|
}
|
|
}
|
|
return nil
|
|
}
|