添加 github.com/pion/dtls 代码

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

@@ -0,0 +1,29 @@
+package handshake
+
+import "encoding/binary"
+
+func decodeCipherSuiteIDs(buf []byte) ([]uint16, error) {
+	if len(buf) < 2 {
+		return nil, errBufferTooSmall
+	}
+	cipherSuitesCount := int(binary.BigEndian.Uint16(buf[0:])) / 2
+	rtrn := make([]uint16, cipherSuitesCount)
+	for i := 0; i < cipherSuitesCount; i++ {
+		if len(buf) < (i*2 + 4) {
+			return nil, errBufferTooSmall
+		}
+
+		rtrn[i] = binary.BigEndian.Uint16(buf[(i*2)+2:])
+	}
+	return rtrn, nil
+}
+
+func encodeCipherSuiteIDs(cipherSuiteIDs []uint16) []byte {
+	out := []byte{0x00, 0x00}
+	binary.BigEndian.PutUint16(out[len(out)-2:], uint16(len(cipherSuiteIDs)*2))
+	for _, id := range cipherSuiteIDs {
+		out = append(out, []byte{0x00, 0x00}...)
+		binary.BigEndian.PutUint16(out[len(out)-2:], id)
+	}
+	return out
+}