Keychain sharing between two apps - ios

Question

Apple has provided Generic Keychain sample which is written in Swift, I want to go ahead with Objective-C.
I have enabled keychain sharing in both the apps and on canOpenUrl I am able to invoke application B from A, now I want to share username and password from app A to app B. App ID is same for both the applications.
I have looked at various tutorials also don't want to use any third party project.
Could not came to know how to pass the parameter from app A to app B.

Answer 1

Enable Keychain sharing:
Turn on the Keychain Sharing capability.
Select developer team
Specify Keychain group name to something meaningful (for example testKeychainG1)
Open .entitlements file and replace $(AppIdentifierPrefix) with your APP ID (for example AB123CDE45.testKeychainG1)
Accessing Keychain (Retrieve shared items):
let itemKey = "Item Key"
let keychainAccessGroupName = "AB123CDE45.testKeychainG1"
let query:[String:Any] = [
kSecClass as String: kSecClassGenericPassword,
kSecAttrAccount as String: itemKey,
kSecReturnData as String: kCFBooleanTrue,
kSecMatchLimit as String: kSecMatchLimitOne,
kSecAttrAccessGroup as String: keychainAccessGroupName
]
var result: AnyObject?
let resultCodeLoad = withUnsafeMutablePointer(to: &result) {
SecItemCopyMatching(query as CFDictionary, UnsafeMutablePointer($0))
}
if resultCodeLoad == noErr {
if let result = result as? Data,
let keyValue = NSString(data: result,
encoding: String.Encoding.utf8.rawValue) as? String {
// Found successfully
print(keyValue)
}
} else {
print("Error: \(resultCodeLoad)")
}

Answer 2

step 1:
Set URL Schemes and add the AppA's URL Scheme to the AppB's info.plist like this:<key>LSApplicationQueriesSchemes</key>
<array>
<string>Aapp_Scheme</string>
</array>
step 2:
In app A:
let url = URL.init(string: "B_Scheme://name=Obama&password=Trump");
if UIApplication.shared.canOpenURL(url) {
UIApplication.shared.open(url, options: ["":""], completionHandler: nil);
}
step 3:
In app B's AppDelegate.swift add the code:
func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {
var name = "", password = "";
let param = url.absoluteString.replacingOccurrences(of: "B_Scheme://", with: "");
let paramArray = param.components(separatedBy: "&");
for temp in paramArray {
if (temp.range(of: "name=") != nil){
name = temp.replacingOccurrences(of: "name=", with: "");
}
else if (temp.range(of: "password=") != nil){
password = temp.replacingOccurrences(of: "password=", with: "");
}
}
if name == "Obama" && password == "Trump" {
print("get param success!");
}
return true;
}