A key whose value is a string to match against the beginning of a certificate or identity's subject.
The corresponding value is of type
CFStringRef. If provided, returned certificates or identities are limited to those whose subject starts with this string.
Item Search Matching Keys
A key whose value indicates a policy with which a matching certificate or identity must verify.
A key whose value is a string to match against a certificate or identity's issuers.
A key whose value is a Boolean indicating whether untrusted certificates should be returned.