[Unique Device ID] How to get an unique device id to use for some purpose in a mobile app. #xamarin #ios #android #wp #mobile

androidId.cs

// --------------------------------------
// ANDROID
// --------------------------------------
var id = Android.OS.Build.Serial;

iosId.cs

// --------------------------------------
// iOS
// --------------------------------------
/*
 * The value of CurrentDevice.IdentifierForVendor changes if the app is removed and reinstalled.
 * Therefore some ID (the value of IdentifierForVendor) is stored to the keychain and
 * reused every time (even after a reinstall). See http://stackoverflow.com/a/22937460
 */
 
String id;
 
String ServiceId = "KeyChainAccountStore";
 
//use the bundle identifier of the app to identifie the value in the keychain
String appId = NSBundle.MainBundle.InfoDictionary["CFBundleIdentifier"].ToString();
 
//Try to read the id from the keychain
var rec = new SecRecord(SecKind.GenericPassword)
{
    Service = ServiceId,
    Account = appId,
};
 
SecStatusCode res;
var match = SecKeyChain.QueryAsRecord(rec, out res);
 
//Store a new ID to the keychain
if (match?.Generic == null)
{
    //Get the vendor ID (does change after a reinstall of the app)
    var vendorId = UIKit.UIDevice.CurrentDevice.IdentifierForVendor.AsString().Replace("-", "");
 
    SecRecord record = new SecRecord(SecKind.GenericPassword)
    {
        Service = ServiceId,
        Account = appId,
        Generic = NSData.FromString(vendorId),
        Accessible = SecAccessible.Always
    };
 
    var statusCode = SecKeyChain.Add(record);
 
    if(statusCode != SecStatusCode.Success)
        Debug.WriteLine("Could not save key to KeyChain: " + statusCode);
 
    id = vendorId;
}
else
{   //Use ID from keychain
    id = match.Generic.ToString();
}
 
return id;

windowsId.cs

// --------------------------------------
// WUP & WINDOWS PHONE 8.1
// --------------------------------------
using Windows.Security.Cryptography;
using Windows.Security.Cryptography.Core;
 
String id = NoDevieIdFound;
try
{
    var token = HardwareIdentification.GetPackageSpecificToken(null);
    var hardwareId = token.Id;
 
    byte[] bytes = new byte[hardwareId.Length];
 
    using (var dataReader = DataReader.FromBuffer(hardwareId))
        dataReader.ReadBytes(bytes);
 
    //create the MD5 hash of the device id to create a shorter id
    var alg = HashAlgorithmProvider.OpenAlgorithm(HashAlgorithmNames.Md5);
    var hashed = alg.HashData(CryptographicBuffer.CreateFromByteArray(bytes));
    id = CryptographicBuffer.EncodeToHexString(hashed);
}
catch (Exception)
{
    //ignore
}