/
message.go
135 lines (113 loc) · 3.03 KB
/
message.go
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// Copyright 2018-2020 opcua authors. All rights reserved.
// Use of this source code is governed by a MIT-style license that can be
// found in the LICENSE file.
package uasc
import (
"github.com/355911097/opcua/errors"
"github.com/355911097/opcua/ua"
)
type MessageHeader struct {
*Header
*AsymmetricSecurityHeader
*SymmetricSecurityHeader
*SequenceHeader
}
func (m *MessageHeader) Decode(b []byte) (int, error) {
buf := ua.NewBuffer(b)
m.Header = new(Header)
buf.ReadStruct(m.Header)
switch m.Header.MessageType {
case "OPN":
m.AsymmetricSecurityHeader = new(AsymmetricSecurityHeader)
buf.ReadStruct(m.AsymmetricSecurityHeader)
case "MSG", "CLO":
m.SymmetricSecurityHeader = new(SymmetricSecurityHeader)
buf.ReadStruct(m.SymmetricSecurityHeader)
default:
return buf.Pos(), errors.Errorf("invalid message type %q", m.Header.MessageType)
}
// Sequence header could be encrypted, defer decoding until after decryption
m.SequenceHeader = new(SequenceHeader)
//buf.ReadStruct(m.SequenceHeader)
return buf.Pos(), buf.Error()
}
type MessageChunk struct {
*MessageHeader
Data []byte
}
func (m *MessageChunk) Decode(b []byte) (int, error) {
m.MessageHeader = new(MessageHeader)
n, err := m.MessageHeader.Decode(b)
if err != nil {
return n, err
}
m.Data = b[n:]
return len(b), nil
}
// MessageAbort represents a non-terminal OPC UA Secure Channel error.
//
// Specification: Part6, 7.3
type MessageAbort struct {
ErrorCode uint32
Reason string
}
func (m *MessageAbort) Decode(b []byte) (int, error) {
buf := ua.NewBuffer(b)
m.ErrorCode = buf.ReadUint32()
m.Reason = buf.ReadString()
return buf.Pos(), buf.Error()
}
func (m *MessageAbort) Encode() ([]byte, error) {
buf := ua.NewBuffer(nil)
buf.WriteUint32(m.ErrorCode)
buf.WriteString(m.Reason)
return buf.Bytes(), buf.Error()
}
func (m *MessageAbort) MessageAbort() string {
return ua.StatusCode(m.ErrorCode).Error()
}
// Message represents a OPC UA Secure Conversation message.
type Message struct {
*MessageHeader
TypeID *ua.ExpandedNodeID
Service interface{}
}
func (m *Message) Decode(b []byte) (int, error) {
m.MessageHeader = new(MessageHeader)
var pos int
n, err := m.MessageHeader.Decode(b)
if err != nil {
return n, err
}
pos += n
m.SequenceHeader = new(SequenceHeader)
n, err = m.SequenceHeader.Decode(b[pos:])
if err != nil {
return n, err
}
pos += n
m.TypeID, m.Service, err = ua.DecodeService(b[pos:])
return len(b), err
}
func (m *Message) Encode() ([]byte, error) {
body := ua.NewBuffer(nil)
switch m.Header.MessageType {
case "OPN":
body.WriteStruct(m.AsymmetricSecurityHeader)
case "CLO", "MSG":
body.WriteStruct(m.SymmetricSecurityHeader)
default:
return nil, errors.Errorf("invalid message type %q", m.Header.MessageType)
}
body.WriteStruct(m.SequenceHeader)
body.WriteStruct(m.TypeID)
body.WriteStruct(m.Service)
if body.Error() != nil {
return nil, body.Error()
}
m.Header.MessageSize = uint32(12 + body.Len())
buf := ua.NewBuffer(nil)
buf.WriteStruct(m.Header)
buf.Write(body.Bytes())
return buf.Bytes(), buf.Error()
}