public DSACryptoServiceProvider(int dwKeySize, CspParameters parameters)
{
byte[] key;
int result;
// The Microsoft documentation is a little fuzzy as to
// when this class retrieves a key, generates a new key,
// or simply waits for the program to supply parameters
// using "ImportParameters".
//
// If we are given a key container name, we ask the runtime
// engine for the corresponding key. The engine can either
// return the key, say that there is no key, reject access
// because the user doesn't want the program to use the key,
// or tell the code to generate a new key for the user.
//
// If we are not given a key container name, we assume that
// the program will be supplying the parameters later.
//
if (parameters != null && parameters.KeyContainerName != null)
{
// Attempt to get a DSA key from the user's keychain.
key = CryptoMethods.GetKey(CryptoMethods.DSASign,
parameters.KeyContainerName,
parameters.Flags,
out result);
if (key != null)
{
// The "ASN1ToPublic" method will determine if
// the key is X.509, bare public, or private.
dsaParams.ASN1ToPublic(key, 0, key.Length);
Array.Clear(key, 0, key.Length);
persistKey = true;
}
else if (result == CryptoMethods.UnknownKey)
{
throw new CryptographicException
(_("Crypto_UnknownKey"),
parameters.KeyContainerName);
}
else if (result == CryptoMethods.NotPermitted)
{
throw new CryptographicException
(_("Crypto_NoKeyAccess"),
parameters.KeyContainerName);
}
else if (result == CryptoMethods.GenerateKey)
{
// Generate a new key for the user.
// TODO
}
}
}
public RSACryptoServiceProvider(int dwKeySize, CspParameters parameters)
{
byte[] key;
int result;
// See "DSACryptoServiceProvider" for explainatory comments.
if (parameters != null && parameters.KeyContainerName != null)
{
// Attempt to get an RSA key from the user's keychain.
key = CryptoMethods.GetKey(CryptoMethods.RSAEncrypt,
parameters.KeyContainerName,
parameters.Flags,
out result);
if (key != null)
{
// The "ASN1ToPublic" method will determine if
// the key is X.509, bare public, or private.
rsaParams.ASN1ToPublic(key, 0, key.Length);
Array.Clear(key, 0, key.Length);
persistKey = true;
}
else if (result == CryptoMethods.UnknownKey)
{
throw new CryptographicException
(_("Crypto_UnknownKey"),
parameters.KeyContainerName);
}
else if (result == CryptoMethods.NotPermitted)
{
throw new CryptographicException
(_("Crypto_NoKeyAccess"),
parameters.KeyContainerName);
}
else if (result == CryptoMethods.GenerateKey)
{
// Generate a new key for the user.
// TODO
}
}
}
