incomplete research for a way to delete private keys from the macOS Keychain

macos-keychain-research.m

//
//  main.m
//  macos-keychain-delete-private-key
//
//  Created by Ron Waldon on 2016-08-30.
//  Copyright © 2016 Ron Waldon. All rights reserved.
//

#import <Foundation/Foundation.h>
#import <Security/Security.h>

// https://stackoverflow.com/questions/27824829/delete-private-key-from-keychain-mac-programmatically

NSString * NSDataToHex (NSData *data) {
    // https://stackoverflow.com/a/12442672/488373
    NSUInteger dataLength = [data length];
    NSMutableString *string = [NSMutableString stringWithCapacity:dataLength * 2];
    const unsigned char *dataBytes = [data bytes];
    for (NSInteger idx = 0; idx < dataLength; ++idx) {
        [string appendFormat:@"%02x", dataBytes[idx]];
    }
    return string;
}

void NSLogSecKeychainCertificate (NSString *name) {
    OSStatus status;

    const NSMutableDictionary *query = [NSMutableDictionary new];

    [query setObject:(__bridge id)kSecClassCertificate forKey:(__bridge id)kSecClass];
    [query setObject:name forKey:(__bridge id)kSecAttrLabel];
    [query setObject:(__bridge id)kCFBooleanTrue forKey:(__bridge id)kSecReturnAttributes];
    [query setObject:(__bridge id)kSecMatchLimitOne forKey:(__bridge id)kSecMatchLimit];

    CFTypeRef result = NULL;

    status = SecItemCopyMatching((__bridge CFDictionaryRef )query, &result);
    NSLog(@"SecItemCopyMatching: %@", SecCopyErrorMessageString(status, NULL));

    NSDictionary *dict = (__bridge NSDictionary *)(CFDictionaryRef) result;
    NSLog(@"NSLogSecKeychainCertificate: %@", dict);

    NSData *pkhh = [dict valueForKey:(NSString *)kSecAttrPublicKeyHash];
    NSLog(@"NSLogSecKeychainCertificate: %@", NSDataToHex(pkhh));
}

void NSLogSecKeychainKey (NSString *name) {
    OSStatus status;

    const NSMutableDictionary *query = [NSMutableDictionary new];

    [query setObject:(__bridge id)kSecClassKey forKey:(__bridge id)kSecClass];
    [query setObject:name forKey:(__bridge id)kSecAttrLabel];
    [query setObject:(__bridge id)kCFBooleanTrue forKey:(__bridge id)kSecReturnAttributes];
    [query setObject:(__bridge id)kSecMatchLimitOne forKey:(__bridge id)kSecMatchLimit];

    CFTypeRef result = NULL;

    status = SecItemCopyMatching((__bridge CFDictionaryRef )query, &result);
    NSLog(@"SecItemCopyMatching: %@", SecCopyErrorMessageString(status, NULL));

    NSDictionary *dict = (__bridge NSDictionary *)(CFDictionaryRef) result;
    NSLog(@"NSLogSecKeychainKey: %@", dict);

    NSData *klbl = [dict valueForKey:(NSString *)kSecAttrApplicationLabel];
    NSLog(@"NSLogSecKeychainKey: %@", NSDataToHex(klbl));
}

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        NSLogSecKeychainCertificate(@"Internet Widgits Pty Ltd");
        NSLogSecKeychainKey(@"self-signed-2016-08-30T02:50:37Z");
    }

    return 0;
}