internal static RSA DecodeRSA(byte[] rawPublicKey)
{
RSAParameters parameters = default(RSAParameters);
try
{
ASN1 asn = new ASN1(rawPublicKey);
if (asn.Count == 0)
{
throw new CryptographicException(Locale.GetText("Missing RSA modulus and exponent."));
}
ASN1 asn2 = asn[0];
if (asn2 == null || asn2.Tag != 2)
{
throw new CryptographicException(Locale.GetText("Missing RSA modulus."));
}
ASN1 asn3 = asn[1];
if (asn3.Tag != 2)
{
throw new CryptographicException(Locale.GetText("Missing RSA public exponent."));
}
parameters.Modulus = PublicKey.GetUnsignedBigInteger(asn2.Value);
parameters.Exponent = asn3.Value;
}
catch (Exception inner)
{
string text = Locale.GetText("Error decoding the ASN.1 structure.");
throw new CryptographicException(text, inner);
}
int dwKeySize = parameters.Modulus.Length << 3;
RSA rsa = new RSACryptoServiceProvider(dwKeySize);
rsa.ImportParameters(parameters);
return(rsa);
}
internal static DSA DecodeDSA(byte[] rawPublicKey, byte[] rawParameters)
{
DSAParameters parameters = default(DSAParameters);
try
{
ASN1 asn = new ASN1(rawPublicKey);
if (asn.Tag != 2)
{
throw new CryptographicException(Locale.GetText("Missing DSA Y integer."));
}
parameters.Y = PublicKey.GetUnsignedBigInteger(asn.Value);
ASN1 asn2 = new ASN1(rawParameters);
if (asn2 == null || asn2.Tag != 48 || asn2.Count < 3)
{
throw new CryptographicException(Locale.GetText("Missing DSA parameters."));
}
if (asn2[0].Tag != 2 || asn2[1].Tag != 2 || asn2[2].Tag != 2)
{
throw new CryptographicException(Locale.GetText("Invalid DSA parameters."));
}
parameters.P = PublicKey.GetUnsignedBigInteger(asn2[0].Value);
parameters.Q = PublicKey.GetUnsignedBigInteger(asn2[1].Value);
parameters.G = PublicKey.GetUnsignedBigInteger(asn2[2].Value);
}
catch (Exception inner)
{
string text = Locale.GetText("Error decoding the ASN.1 structure.");
throw new CryptographicException(text, inner);
}
DSA dsa = new DSACryptoServiceProvider(parameters.Y.Length << 3);
dsa.ImportParameters(parameters);
return(dsa);
}