Objective-c Class for managing OSX keychains and keychain items.

This is project is a derivative of SSKeychain https://github.com/soffes/sskeychain/

There are four enhancements of this project

1. It lets the user specify which keychain work with, such as the system keychain or a keychain on an external drive/SD card.

2. The other added feature is the ability to specify an Array of trusted apps granted access to the keychain item.

3. This also gives you the ability to change the keychain's password .

4. The other minor improvement is that it actually updates the keychain item using SecItemUpdate(). SSKeychain actually deletes and re-adds the keychain item which can cause peculiar behavior when an app is not code signed and has proper entitlements.

Working with a specific keychain.

To specify the default login keychain

AHKeychain *keychain = [AHKeychain loginKeychain];

To specify the system keychain

to write to this keychain you application must run as root

AHKeychain *keychain = [AHKeychain systemKeychain];

To specify a keychain at a particular path (external drive)

AHKeychain *keychain = [AHKeychain keychainAtPath:@"/Volumes/MyExternalHD/Library/Keychains/myextkc.keychain"];

To create a new user keychain

AHKeychain *keychain = [AHKeychain alloc]initCreatingNewKeychain:@"Test Keychain"
                                                    password:@"realfakepsswd"];

To remove the keychain file. It's Destructive!

*calling this method on either the login keychain or the system keychain will fail

[keychain deleteKeychain];

Modifying a keychain item.

To add/update an item

AHKeychainItem *item = [AHkeychainItem alloc] init];
item.service = @"com.eeaapps.test";
item.account = @"myusername";
item.label = @"AHKeychain Test Keychain Item";
item.password = @"mysecretpass";

// also if you want to allow other app to access the keychain item
NSArray *trustedApps = [NSArray arrayWithObjects:@"/Applications/Mail.app",
                                                 @"/Applications/Preview.app",
                                                 nil];
item.trustedApplications = trustedApps;

[keychain saveItem:item error:&error];

To get an item's password

AHKeychainItem *item = [AHkeychainItem alloc] init];
item.service = @"com.eeaapps.test";
item.account = @"myusername";

[keychain getItem:item error:&error];

NSLog(@"The Password is %@",item.password);

To remove a keychain item

AHKeychainItem *item = [AHkeychainItem alloc] init];
item.service = @"com.eeaapps.test";
item.account = @"myusername";
[keychain deleteItem:item error:&error];

Class Methods for convenience

there are two keychain constants that refer to standard keychains

kAHKeychainLoginKeychain
kAHKeychainSystemKeychain

You can use either of these, or specify a full path to the keychain file in the following methods

Setting a password

[AHKeychain setPassword:@"mysecretpass" 
                service:@"com.eeaapps.testkc" 
                account:@"myusername" 
               keychain:kAHKeychainLoginKeychain 
                  error:&error];

Getting a password

NSError *error;    
NSString *password = [AHKeychain getPasswordForService:item.service
                                               account:item.account
                                              keychain:kAHKeychainLoginKeychain
                                                 error:&error];

NSLog(@"The Password is %@",item.password);

See AHKeychain.h and AHKeychainItem.h for more info.