diff options
Diffstat (limited to 'vendor/github.com/pion/dtls/v2/pkg/protocol/handshake/header.go')
-rw-r--r-- | vendor/github.com/pion/dtls/v2/pkg/protocol/handshake/header.go | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/vendor/github.com/pion/dtls/v2/pkg/protocol/handshake/header.go b/vendor/github.com/pion/dtls/v2/pkg/protocol/handshake/header.go new file mode 100644 index 0000000..cb6a224 --- /dev/null +++ b/vendor/github.com/pion/dtls/v2/pkg/protocol/handshake/header.go @@ -0,0 +1,50 @@ +package handshake + +import ( + "encoding/binary" + + "github.com/pion/dtls/v2/internal/util" +) + +// HeaderLength msg_len for Handshake messages assumes an extra +// 12 bytes for sequence, fragment and version information vs TLS +const HeaderLength = 12 + +// Header is the static first 12 bytes of each RecordLayer +// of type Handshake. These fields allow us to support message loss, reordering, and +// message fragmentation, +// +// https://tools.ietf.org/html/rfc6347#section-4.2.2 +type Header struct { + Type Type + Length uint32 // uint24 in spec + MessageSequence uint16 + FragmentOffset uint32 // uint24 in spec + FragmentLength uint32 // uint24 in spec +} + +// Marshal encodes the Header +func (h *Header) Marshal() ([]byte, error) { + out := make([]byte, HeaderLength) + + out[0] = byte(h.Type) + util.PutBigEndianUint24(out[1:], h.Length) + binary.BigEndian.PutUint16(out[4:], h.MessageSequence) + util.PutBigEndianUint24(out[6:], h.FragmentOffset) + util.PutBigEndianUint24(out[9:], h.FragmentLength) + return out, nil +} + +// Unmarshal populates the header from encoded data +func (h *Header) Unmarshal(data []byte) error { + if len(data) < HeaderLength { + return errBufferTooSmall + } + + h.Type = Type(data[0]) + h.Length = util.BigEndianUint24(data[1:]) + h.MessageSequence = binary.BigEndian.Uint16(data[4:]) + h.FragmentOffset = util.BigEndianUint24(data[6:]) + h.FragmentLength = util.BigEndianUint24(data[9:]) + return nil +} |