How to fetch certificates from the user's keychain using Swift

gistfile1.txt

import Foundation
import Security

var dataTypeRef: CFTypeRef?
let rv = SecItemCopyMatching(
    [
        kSecClass: kSecClassCertificate,
        kSecReturnAttributes: true,
        kSecReturnRef: true,
        kSecReturnData: true,
        kSecMatchLimit: kSecMatchLimitAll
    ] as CFDictionary,
    &dataTypeRef
)

var data : NSArray?
data = dataTypeRef as? NSArray
for element in data! {
	let dict : NSDictionary = element as! NSDictionary
	let cert : SecCertificate = dict.object(forKey: kSecValueRef) as! SecCertificate
	let summary = SecCertificateCopySubjectSummary(cert);
	
	print(summary ?? "")
}

You may want to update that code. First part with Swift 5 would be:

import Foundation
import Security

var dataTypeRef: CFTypeRef?
let rv = SecItemCopyMatching(
    [
        kSecClass: kSecClassCertificate,
        kSecReturnAttributes: true,
        kSecReturnRef: true,
        kSecReturnData: true,
        kSecMatchLimit: kSecMatchLimitAll
    ] as CFDictionary,
    &dataTypeRef
)

Yes I put this together back in the days of Swift 1 and 2, it is amazing how much the language has advanced. I've updated it in case someone finds it again, thanks.