/// <summary>
/// Verify signature.
/// </summary>
/// <param name="content">content to be signed.</param>
/// <param name="sign">the signature to verified.</param>
/// <param name="publicKey">public key.</param>
/// <returns>if verifying signature succeed.</returns>
public static bool DoCheck(sbyte[] content, string sign, string publicKey)
{
try
{
KeyFactory keyFactory = KeyFactory.GetInstance("RSA");
sbyte[] encodedKey = (sbyte[])(Array)Base64.Decode(publicKey, Base64Flags.Default);
IPublicKey pubKey = keyFactory.GeneratePublic(new X509EncodedKeySpec((byte[])(Array)encodedKey));
Java.Security.Signature signature = Java.Security.Signature.GetInstance(SignAlgorithms256);
signature.InitVerify(pubKey);
signature.Update((byte[])(Array)content);
return(signature.Verify(Base64.Decode(sign, Base64Flags.Default)));
}
catch (Exception ex)
{
Log.Info("RSA", "DoCheck fail: " + ex.Message);
throw;
}
}
/// <summary>
/// Sign content.
/// </summary>
/// <param name="content">data to be signed.</param>
/// <param name="privateKey">merchant's private key.</param>
/// <returns> Signed value.</returns>
public static string SignContent(string content, string privateKey)
{
try
{
PKCS8EncodedKeySpec privatePKCS8 = new PKCS8EncodedKeySpec(Base64.Decode(privateKey, Base64Flags.Default));
KeyFactory keyf = KeyFactory.GetInstance("RSA");
IPrivateKey priKey = keyf.GeneratePrivate(privatePKCS8);
Java.Security.Signature signatureObj = Java.Security.Signature.GetInstance(SignAlgorithms256);
signatureObj.InitSign(priKey);
signatureObj.Update(Encoding.UTF8.GetBytes(content));
sbyte[] signed = (sbyte[])(Array)signatureObj.Sign();
return(Base64.EncodeToString((byte[])(Array)signed, Base64Flags.Default));
}
catch (Exception ex)
{
Log.Info("RSA", "Sign fail: " + ex.Message);
throw;
}
}
private void ShowBiometricPrompt(Java.Security.Signature signature)
{
// Create biometric prompt
var activity = MainActivity.FormsContext;
var negativeButtonListener = new DialogInterfaceOnClickListener(() => {
// Do something here.
});
biometricPrompt = new BiometricPrompt.Builder(activity)
.SetDescription("Never Been Easier")
.SetTitle("Biometric Prompt Authentication")
.SetSubtitle("Please allow Xamarin Life to authenticate")
.SetNegativeButton("Cancel", activity.MainExecutor, negativeButtonListener)
.Build();
// Show biometric prompt
var cancellationSignal = new CancellationSignal();
var authenticationCallback = GetAuthenticationCallback();
biometricPrompt.Authenticate(new BiometricPrompt.CryptoObject(signature), cancellationSignal, activity.MainExecutor, authenticationCallback);
}