The Device Specific Key (DSK) is a 16-byte identifier unique to each S2-capable device. It's represented as a string ("34028-23669-20938-46346-33746-07431-56821-14553" - 8 groups of 5 decimal digits each representing 2 bytes). The QR code encodes the DSK plus metadata in a TLV-based binary format.
Scope:
- DSK type in
ZWave.Protocol: a 16-byte value type with:
Parse(string) / ToString() - convert to/from the "XXXXX-XXXXX-..." formatPin property - first 5 digits (first 2 bytes), used for S2 authenticationNwiHomeId / AuthHomeId - derived HomeIDs for SmartStart Prime matchingTryParse, validation, equality/hashing
- QR code parser: Parse the Z-Wave QR code data string (starts with "90" prefix):
- Extract DSK (always present)
- Parse TLV blocks: Product Type (0x00), Product ID (0x01), Max Inclusion Request Interval (0x02), UUID16 (0x03), Supported Protocols (0x04)
- Extract requested security classes bitmask
- Checksum validation (CRC-16 per spec)
- Unit tests with known DSK/QR test vectors
Design notes: The DSK type should be a readonly record struct in ZWave.Protocol since it's used across layers. The QR parser can live in a new utility class. Make the DSK a proper value type - C# structs are ideal for this.
The Device Specific Key (DSK) is a 16-byte identifier unique to each S2-capable device. It's represented as a string ("34028-23669-20938-46346-33746-07431-56821-14553" - 8 groups of 5 decimal digits each representing 2 bytes). The QR code encodes the DSK plus metadata in a TLV-based binary format.
Scope:
ZWave.Protocol: a 16-byte value type with:Parse(string)/ToString()- convert to/from the "XXXXX-XXXXX-..." formatPinproperty - first 5 digits (first 2 bytes), used for S2 authenticationNwiHomeId/AuthHomeId- derived HomeIDs for SmartStart Prime matchingTryParse, validation, equality/hashingDesign notes: The DSK type should be a
readonly record structinZWave.Protocolsince it's used across layers. The QR parser can live in a new utility class. Make the DSK a proper value type - C# structs are ideal for this.