添加 github.com/pion/dtls 代码

dtls-2.0.9/pkg/protocol/alert/alert.go

@@ -0,0 +1,160 @@
+// Package alert implements TLS alert protocol https://tools.ietf.org/html/rfc5246#section-7.2
+package alert
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/pion/dtls/v2/pkg/protocol"
+)
+
+var errBufferTooSmall = &protocol.TemporaryError{Err: errors.New("buffer is too small")} //nolint:goerr113
+
+// Level is the level of the TLS Alert
+type Level byte
+
+// Level enums
+const (
+	Warning Level = 1
+	Fatal   Level = 2
+)
+
+func (l Level) String() string {
+	switch l {
+	case Warning:
+		return "Warning"
+	case Fatal:
+		return "Fatal"
+	default:
+		return "Invalid alert level"
+	}
+}
+
+// Description is the extended info of the TLS Alert
+type Description byte
+
+// Description enums
+const (
+	CloseNotify            Description = 0
+	UnexpectedMessage      Description = 10
+	BadRecordMac           Description = 20
+	DecryptionFailed       Description = 21
+	RecordOverflow         Description = 22
+	DecompressionFailure   Description = 30
+	HandshakeFailure       Description = 40
+	NoCertificate          Description = 41
+	BadCertificate         Description = 42
+	UnsupportedCertificate Description = 43
+	CertificateRevoked     Description = 44
+	CertificateExpired     Description = 45
+	CertificateUnknown     Description = 46
+	IllegalParameter       Description = 47
+	UnknownCA              Description = 48
+	AccessDenied           Description = 49
+	DecodeError            Description = 50
+	DecryptError           Description = 51
+	ExportRestriction      Description = 60
+	ProtocolVersion        Description = 70
+	InsufficientSecurity   Description = 71
+	InternalError          Description = 80
+	UserCanceled           Description = 90
+	NoRenegotiation        Description = 100
+	UnsupportedExtension   Description = 110
+)
+
+func (d Description) String() string {
+	switch d {
+	case CloseNotify:
+		return "CloseNotify"
+	case UnexpectedMessage:
+		return "UnexpectedMessage"
+	case BadRecordMac:
+		return "BadRecordMac"
+	case DecryptionFailed:
+		return "DecryptionFailed"
+	case RecordOverflow:
+		return "RecordOverflow"
+	case DecompressionFailure:
+		return "DecompressionFailure"
+	case HandshakeFailure:
+		return "HandshakeFailure"
+	case NoCertificate:
+		return "NoCertificate"
+	case BadCertificate:
+		return "BadCertificate"
+	case UnsupportedCertificate:
+		return "UnsupportedCertificate"
+	case CertificateRevoked:
+		return "CertificateRevoked"
+	case CertificateExpired:
+		return "CertificateExpired"
+	case CertificateUnknown:
+		return "CertificateUnknown"
+	case IllegalParameter:
+		return "IllegalParameter"
+	case UnknownCA:
+		return "UnknownCA"
+	case AccessDenied:
+		return "AccessDenied"
+	case DecodeError:
+		return "DecodeError"
+	case DecryptError:
+		return "DecryptError"
+	case ExportRestriction:
+		return "ExportRestriction"
+	case ProtocolVersion:
+		return "ProtocolVersion"
+	case InsufficientSecurity:
+		return "InsufficientSecurity"
+	case InternalError:
+		return "InternalError"
+	case UserCanceled:
+		return "UserCanceled"
+	case NoRenegotiation:
+		return "NoRenegotiation"
+	case UnsupportedExtension:
+		return "UnsupportedExtension"
+	default:
+		return "Invalid alert description"
+	}
+}
+
+// Alert is one of the content types supported by the TLS record layer.
+// Alert messages convey the severity of the message
+// (warning or fatal) and a description of the alert.  Alert messages
+// with a level of fatal result in the immediate termination of the
+// connection.  In this case, other connections corresponding to the
+// session may continue, but the session identifier MUST be invalidated,
+// preventing the failed session from being used to establish new
+// connections.  Like other messages, alert messages are encrypted and
+// compressed, as specified by the current connection state.
+// https://tools.ietf.org/html/rfc5246#section-7.2
+type Alert struct {
+	Level       Level
+	Description Description
+}
+
+// ContentType returns the ContentType of this Content
+func (a Alert) ContentType() protocol.ContentType {
+	return protocol.ContentTypeAlert
+}
+
+// Marshal returns the encoded alert
+func (a *Alert) Marshal() ([]byte, error) {
+	return []byte{byte(a.Level), byte(a.Description)}, nil
+}
+
+// Unmarshal populates the alert from binary data
+func (a *Alert) Unmarshal(data []byte) error {
+	if len(data) != 2 {
+		return errBufferTooSmall
+	}
+
+	a.Level = Level(data[0])
+	a.Description = Description(data[1])
+	return nil
+}
+
+func (a *Alert) String() string {
+	return fmt.Sprintf("Alert %s: %s", a.Level, a.Description)
+}

dtls-2.0.9/pkg/protocol/alert/alert_test.go

@@ -0,0 +1,49 @@
+package alert
+
+import (
+	"errors"
+	"reflect"
+	"testing"
+)
+
+func TestAlert(t *testing.T) {
+	for _, test := range []struct {
+		Name               string
+		Data               []byte
+		Want               *Alert
+		WantUnmarshalError error
+	}{
+		{
+			Name: "Valid Alert",
+			Data: []byte{0x02, 0x0A},
+			Want: &Alert{
+				Level:       Fatal,
+				Description: UnexpectedMessage,
+			},
+		},
+		{
+			Name:               "Invalid alert length",
+			Data:               []byte{0x00},
+			Want:               &Alert{},
+			WantUnmarshalError: errBufferTooSmall,
+		},
+	} {
+		a := &Alert{}
+		if err := a.Unmarshal(test.Data); !errors.Is(err, test.WantUnmarshalError) {
+			t.Errorf("Unexpected Error %v: exp: %v got: %v", test.Name, test.WantUnmarshalError, err)
+		} else if !reflect.DeepEqual(test.Want, a) {
+			t.Errorf("%q alert.unmarshal: got %v, want %v", test.Name, a, test.Want)
+		}
+
+		if test.WantUnmarshalError != nil {
+			return
+		}
+
+		data, marshalErr := a.Marshal()
+		if marshalErr != nil {
+			t.Errorf("Unexpected Error %v: got: %v", test.Name, marshalErr)
+		} else if !reflect.DeepEqual(test.Data, data) {
+			t.Errorf("%q alert.marshal: got % 02x, want % 02x", test.Name, data, test.Data)
+		}
+	}
+}