private static ICipherParameters GetPrivateParameters(IKey privateKey, AsymmetricRsaKey.Usage rsaUsage)
{
if (privateKey is KeyWithRandom)
{
KeyWithRandom k = (KeyWithRandom)privateKey;
return(new ParametersWithRandom(GetPrivateKeyParameters((AsymmetricRsaPrivateKey)k.Key, rsaUsage), k.Random));
}
else
{
return(new ParametersWithRandom(GetPrivateKeyParameters((AsymmetricRsaPrivateKey)privateKey, rsaUsage), CryptoServicesRegistrar.GetSecureRandom()));
}
}
private static void CheckKeyUsage(AsymmetricRsaKey key, AsymmetricRsaKey.Usage usage)
{
// FSM_STATE:5.12,"RSA KEY USAGE CHECK", "The module verifies recent usage of an RSA key is consistent with requested usage"
// FSM_TRANS:5.RSAK.0,"CONDITIONAL TEST", "RSA KEY USAGE CHECK", "Invoke RSA key usage check"
if (!key.CanBeUsed(usage))
{
// FSM_TRANS:5.RSAK.2,"RSA KEY USAGE CHECK", "USER COMMAND REJECTED", "RSA key usage check failed"
if (usage == AsymmetricRsaKey.Usage.SignOrVerify)
{
throw new IllegalKeyException("attempt to sign/verify with RSA modulus already used for encrypt/decrypt");
}
else
{
throw new IllegalKeyException("attempt to encrypt/decrypt with RSA modulus already used for sign/verify");
}
}
// FSM_TRANS:5.RSAK.1,"RSA KEY USAGE CHECK", "CONDITIONAL TEST", "RSA key usage check successful"
}
internal static RsaKeyParameters GetPrivateKeyParameters(AsymmetricRsaPrivateKey k, AsymmetricRsaKey.Usage usage)
{
CheckKeyUsage(k, usage);
if (k.PublicExponent.Equals(BigInteger.Zero))
{
return(new RsaKeyParameters(true, k.Modulus, k.PrivateExponent));
}
else
{
return(new RsaPrivateCrtKeyParameters(k.Modulus, k.PublicExponent, k.PrivateExponent, k.P, k.Q, k.DP, k.DQ, k.QInv));
}
}
internal static RsaKeyParameters GetPublicKeyParameters(AsymmetricRsaPublicKey k, AsymmetricRsaKey.Usage usage)
{
CheckKeyUsage(k, usage);
return(new RsaKeyParameters(false, k.Modulus, k.PublicExponent));
}
