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Scope: Core (OPC-10000-*) All specs

14 result(s) for MessageChunk

OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

6.7.1 Overview

Message . A Stack that implements UASC is responsible for verifying the security on each MessageChunk received and reconstructing the original OPC UA Message . All MessageChunks will have a 4-byte
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

6.7.2.1 Overview

Overview The structure of the MessageChunk s exchanged after a SecureChannel is negotiated depends on whether the SecurityPolicy requires a symmetric encryption algorithm that combines encryption and authentication (e.g. AuthenticatedEncryption ... requires separate symmetric algorithms for each operation. Figure 11 shows the structure of a MessageChunk and how security is applied to the Message when not using AuthenticatedEncryption algorithms. For these
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

6.7.2.2 Message Header

Message Header Every MessageChunk has a Message header with the fields defined in Table 57 . Table 57 - OPC UA Secure Conversation Message Header Name Data Type Description MessageType Byte ... CloseSecureChannel Message . IsFinal Byte A one byte ASCII code that indicates whether the MessageChunk is the final chunk in a Message . The following values are defined at this time
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

6.7.2.3 Security Header

defined in X.690 This indicates what Private Key was used to sign the MessageChunk . The Stack shall close the channel and report an error to the application if the SenderCertificate ... When using RSA PublicKeys, it indicates which Public Key was used to encrypt the MessageChunk . When using ECC or RSA-DH Public Keys it indicates the intended recipient
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

6.7.2.4 Sequence Header

Description SequenceNumber UInt32 A monotonically increasing sequence number assigned by the sender to each MessageChunk sent over the SecureChannel . RequestId UInt32 An identifier assigned by the Client ... TokenId is issued and it shall be incremented by exactly one for each MessageChunk sent. SecurityPolicies with LegacySequenceNumbers set to TRUE, the SequenceNumber shall monotonically increase for all Messages
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

6.7.2.5.1 Encryption other than Authenticated Symmetric Encryption (AEAD)

than Authenticated Symmetric Encryption (AEAD) When using encryption with algorithms other than AEAD, each MessageChunk has a footer with the fields defined in Table 61 . Table 61 - Message Footer with ... less than or equal to 2048 bits. Signature OctetString The signature for the MessageChunk . The signature includes the headers, all Message data, the PaddingSize and the Padding . The signature
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

6.7.2.5.2 Authenticated Encryption Algorithms (AEAD)

Authenticated Encryption Algorithms (AEAD) When not using encryption or when using AEAD algorithms, each MessageChunk has a footer with the fields defined in Table 62 . Table 62 - Message Footer ... Mode and AEAD Encryption Name Data Type Description Signature OctetString The signature for the MessageChunk . The signature includes the headers and all Message data. The signature is encoded as sequence
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

6.7.3 MessageChunks and error handling

same Message shall be sent sequentially. If an error occurs creating a MessageChunk then the sender shall send a final MessageChunk to the receiver that tells the receiver that ... occurred and that it should discard the previous chunks. The sender indicates that the MessageChunk contains an error by setting the IsFinal flag to 'A' (for Abort). Table 63 specifies
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

6.7.7 Verifying Message Security

Verifying Message Security The contents of the MessageChunk shall not be interpreted until the Message is decrypted and the signature and sequence number verified. If an error occurs during Message
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

6.8.1 Secure Channel Handshake

discussed in 6.7.1 . When using AuthenticatedEncryption, a unique InitializationVector is required for each MessageChunk . This value is constructed from the ClientInitializationVector or ServerInitializationVector where the first 8 bytes are XORed ... Initialization Vector Name Bytes Length TokenId 4 The TokenId specified in the SecurityHeader of MessageChunk being processed. It is encoded as a UInt32 as described in 5.2.2.2. LastSequenceNumber
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

7.1.2.3 Hello Message

ProtocolVersion for this version of the standard is 0. ReceiveBufferSize UInt32 The largest MessageChunk that the sender can receive. Shall be at least 1024 bytes if the sender intends ... SecurityPolicy . Shall be at least 8192 bytes otherwise. SendBufferSize UInt32 The largest MessageChunk that the sender will send. Shall be at least 1024 bytes if the sender intends
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

7.1.2.4 Acknowledge Message

ProtocolVersion for this version of the standard is 0. ReceiveBufferSize UInt32 The largest MessageChunk that the sender can receive. This value shall not be larger than the SendBufferSize requested ... bytes. Shall be at least 1024 bytes otherwise. SendBufferSize UInt32 The largest MessageChunk that the sender will send. This value shall not be larger than the ReceiveBufferSize requested
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

7.1.5 Error handling

This error is reported by the SecureChannel layer. Bad_TcpMessageTooLarge The size of the MessageChunk specified in the header is too large. The Server returns this error if the MessageChunk
OPC-10000-6 – OPC Unified Architecture - Part 6: Mappings

7.5.2 Sub-Protocols

WebSocket Sub-Protocols Sub-Protocol Description opcua+uacp Each WebSocket frame is a MessageChunk as defined in 6.7.2 . After the WebSocket is created, the handshake described in 7.1.3 is used ... negotiate the maximum size of the MessageChunk . The maximum size for a buffer used to receive a WebSocket frame is the maximum length of a MessageChunk plus the maximum size