添加 github.com/pion/dtls 代码

dtls-2.0.9/pkg/protocol/handshake/random.go

@@ -0,0 +1,49 @@
+package handshake
+
+import (
+	"crypto/rand"
+	"encoding/binary"
+	"time"
+)
+
+// Consts for Random in Handshake
+const (
+	RandomBytesLength = 28
+	RandomLength      = RandomBytesLength + 4
+)
+
+// Random value that is used in ClientHello and ServerHello
+//
+// https://tools.ietf.org/html/rfc4346#section-7.4.1.2
+type Random struct {
+	GMTUnixTime time.Time
+	RandomBytes [RandomBytesLength]byte
+}
+
+// MarshalFixed encodes the Handshake
+func (r *Random) MarshalFixed() [RandomLength]byte {
+	var out [RandomLength]byte
+
+	binary.BigEndian.PutUint32(out[0:], uint32(r.GMTUnixTime.Unix()))
+	copy(out[4:], r.RandomBytes[:])
+
+	return out
+}
+
+// UnmarshalFixed populates the message from encoded data
+func (r *Random) UnmarshalFixed(data [RandomLength]byte) {
+	r.GMTUnixTime = time.Unix(int64(binary.BigEndian.Uint32(data[0:])), 0)
+	copy(r.RandomBytes[:], data[4:])
+}
+
+// Populate fills the handshakeRandom with random values
+// may be called multiple times
+func (r *Random) Populate() error {
+	r.GMTUnixTime = time.Now()
+
+	tmp := make([]byte, RandomBytesLength)
+	_, err := rand.Read(tmp)
+	copy(r.RandomBytes[:], tmp)
+
+	return err
+}