void ComputeIccContext()
{
var issuerModulusLength = new BigInteger(issuerPrivateKey.Modulus, 16).BitLength / 8;
var iccPublicKey = certificateData.IccPrivateKey.GetPublicKey();
var iccModulusLength = new BigInteger(iccPublicKey.Modulus, 16).BitLength / 8;
var iccPublicKeyCertificate = new IccPublicKeyCertificate
{
HashAlgorithmIndicator = certificateData.HashAlgorithmIndicator.FromHexa().First(),
ApplicationPan = certificateData.ApplicationPan.FromHexa(),
CertificateExpirationDate = certificateData.ExpirationDate.FromHexa(),
CertificateSerialNumber = certificateData.SerialNumber.FromHexa(),
PublicKeyAlgorithmIndicator = certificateData.PublicKeyAlgorithmIndicator.FromHexa().First(),
IccPublicKey = iccPublicKey
};
IccContext = new EmvIccContext()
{
ApplicationPan = certificateData.ApplicationPan,
IccPrivateKey = certificateData.IccPrivateKey
};
// 9F46 ICC Public Key Certificate (Nca)
IccContext.IccPublicKeyCertificate = iccPublicKeyCertificate.GenerateCertificate(issuerPrivateKey.GetPrivateKey()).ToHexa();
// 9F48 ICC Public Key Remainder (Ni-Nca+42)
if (iccModulusLength > issuerModulusLength - 42)
{
IccContext.IccPublicKeyRemainder = iccPublicKey.Modulus.FromHexa().Skip(issuerModulusLength - 42).ToArray().ToHexa();
}
// 9F47 ICC Public Key Exponent (1 or 3)
IccContext.IccPrivateKey.PublicExponent = iccPublicKey.Exponent.FromHexa().ToHexa();
}
public static byte[] BuildPinVerifyData(KernelDatabaseBase database, CAPublicKeyCertificate caPublicKey, byte[] pinBlock, byte[] challenge)
{
IssuerPublicKeyCertificate ipk = IssuerPublicKeyCertificate.BuildAndValidatePublicKey(database, caPublicKey.Modulus, caPublicKey.Exponent);
if (ipk == null)
{
return(null);
}
int keyLength = 0;
PublicKeyCertificate iccKey = IccPinKeyCertificate.BuildAndValidatePublicKey(database, ipk.Modulus, ipk.Exponent);
if (iccKey == null)
{
iccKey = IccPublicKeyCertificate.BuildAndValidatePublicKey(database, database.StaticDataToBeAuthenticated, ipk.Modulus, ipk.Exponent);
if (iccKey == null)
{
return(null);
}
keyLength = ((IccPublicKeyCertificate)iccKey).ICCPublicKeyLength;
}
else
{
keyLength = ((IccPinKeyCertificate)iccKey).ICCPinKeyLength;
}
int paddingLength = keyLength - 17;
byte[] padding = new byte[paddingLength];
byte[] pinData = Formatting.ConcatArrays(new byte[] { 0x7F }, pinBlock, challenge, padding);
//apply recovery function
byte[] encryptedPin = PublicKeyCertificate.DecryptRSA(pinData, iccKey.Modulus, iccKey.Exponent);
return(encryptedPin);
}
