添加 github.com/pion/dtls 代码

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

@@ -0,0 +1,61 @@
+package handshake
+
+import (
+	"encoding/binary"
+
+	"github.com/pion/dtls/v2/pkg/crypto/hash"
+	"github.com/pion/dtls/v2/pkg/crypto/signature"
+)
+
+// MessageCertificateVerify provide explicit verification of a
+// client certificate.
+//
+// https://tools.ietf.org/html/rfc5246#section-7.4.8
+type MessageCertificateVerify struct {
+	HashAlgorithm      hash.Algorithm
+	SignatureAlgorithm signature.Algorithm
+	Signature          []byte
+}
+
+const handshakeMessageCertificateVerifyMinLength = 4
+
+// Type returns the Handshake Type
+func (m MessageCertificateVerify) Type() Type {
+	return TypeCertificateVerify
+}
+
+// Marshal encodes the Handshake
+func (m *MessageCertificateVerify) Marshal() ([]byte, error) {
+	out := make([]byte, 1+1+2+len(m.Signature))
+
+	out[0] = byte(m.HashAlgorithm)
+	out[1] = byte(m.SignatureAlgorithm)
+	binary.BigEndian.PutUint16(out[2:], uint16(len(m.Signature)))
+	copy(out[4:], m.Signature)
+	return out, nil
+}
+
+// Unmarshal populates the message from encoded data
+func (m *MessageCertificateVerify) Unmarshal(data []byte) error {
+	if len(data) < handshakeMessageCertificateVerifyMinLength {
+		return errBufferTooSmall
+	}
+
+	m.HashAlgorithm = hash.Algorithm(data[0])
+	if _, ok := hash.Algorithms()[m.HashAlgorithm]; !ok {
+		return errInvalidHashAlgorithm
+	}
+
+	m.SignatureAlgorithm = signature.Algorithm(data[1])
+	if _, ok := signature.Algorithms()[m.SignatureAlgorithm]; !ok {
+		return errInvalidSignatureAlgorithm
+	}
+
+	signatureLength := int(binary.BigEndian.Uint16(data[2:]))
+	if (signatureLength + 4) != len(data) {
+		return errBufferTooSmall
+	}
+
+	m.Signature = append([]byte{}, data[4:]...)
+	return nil
+}