Detailed Description
The byte offsets and lengths of the 51Did payload, for this package and its tests only.
The layout itself is published at https://github.com/51Degrees/specifications/blob/main/did-specification/identifier-layout.md which is the authority for what each byte holds, and https://github.com/51Degrees/specifications/blob/main/did-specification/package-surface.md lists what every 51Did package offers a caller.
A caller reads a 51Did through the named accessors on {
- See also
- FodId}, being {
- FodId::getType()}, {
- FodId::getUsage()}, {
- FodId::isUsageIndirect()}, {
- FodId::getLicenseId()} and {
- FodId::getMatchKey()}, because every bit now has a name and masking the bits by hand is how the usage gets read the wrong way round. See {
- Usage} for why.
Data Fields | |
| const | FLAGS_OFFSET = 0 |
| Byte offset of the Flags field within the payload. | |
| const | LICENSE_ID_OFFSET = 1 |
| Byte offset of the License Id field within the payload. | |
| const | LICENSE_ID_LENGTH = 4 |
| Byte length of the License Id field. | |
| const | MATCH_KEY_OFFSET = 5 |
| Byte offset of the match key field within the payload. | |
| const | MATCH_KEY_LENGTH = 32 |
| Byte length of the match key field (SHA-256). | |
| const | HEADER_LENGTH = self::MATCH_KEY_OFFSET |
| Byte length of the header (Flags + License Id) common to every type. | |
| const | GUID_LENGTH = 16 |
| Byte length of the GUID match key carried by Random identifiers. | |
| const | RANDOM_PAYLOAD_LENGTH = self::HEADER_LENGTH + self::GUID_LENGTH |
| Minimum byte length of a Random 51Did payload. | |
| const | PAYLOAD_LENGTH |
| Minimum byte length of a Probabilistic or HashedEmail 51Did payload (Flags + License Id + match key). | |
Field Documentation
◆ PAYLOAD_LENGTH
| const fiftyone\pipeline\did\FodIdLayout::PAYLOAD_LENGTH |
Initial value:
= self::MATCH_KEY_OFFSET
+ self::MATCH_KEY_LENGTH
Minimum byte length of a Probabilistic or HashedEmail 51Did payload (Flags + License Id + match key).
Random payloads are shorter, see {
- See also
- FodIdLayout::RANDOM_PAYLOAD_LENGTH}.