Module schema 

Relations and attributes — the schema a keychain carries about itself.

A keychain is a CSSM database: four schema tables describe every other table’s attributes, so a reader does not have to hard-code the layout of password or key records. Only the four schema relations themselves need built-in definitions, to bootstrap.

Two things matter and are not obvious:

• A record’s attribute-offset array follows the order attributes are defined in the schema table, not attribute-id order. Sorting by id silently misreads every password record.
• Password relations name most attributes by four-char code in the AttributeID (acct, svce, srvr), leaving AttributeName empty; PrintName and Alias are the exceptions, named by string.

Structs

AttributeDef

One attribute of a relation.

RecordType

A CSSM relation identifier (CSSM_DB_RECORDTYPE).

Relation

Schema

The schema of one keychain.

Enums

AttributeFormat

CSSM_DB_ATTRIBUTE_FORMAT: how an attribute value is encoded.

Functions

four_char_code

Four-char code as a big-endian integer, for building attribute ids.