// key can be expended for HMAC - i.e. a small key, e.g. 32 bytes, is still accepted as valid
// the HMAC class already deals with keys larger than what it can use (digested to right size)
void SetValidationKey(string key)
{
if ((key == null) || key.StartsWith("AutoGenerate"))
{
validation_key = AutoGenerate(MachineKeyRegistryStorage.KeyType.Validation);
}
else
{
try {
validation_key = MachineKeySectionUtils.GetBytes(key, key.Length);
ValidationTemplate.Key = validation_key;
}
catch (CryptographicException) {
// second chance, use the key length that the HMAC really wants
try {
byte[] expanded_key = new byte [ValidationTemplate.Key.Length];
Array.Copy(validation_key, 0, expanded_key, 0, validation_key.Length);
ValidationTemplate.Key = expanded_key;
validation_key = expanded_key;
}
catch {
validation_key = null;
throw new ArgumentException("Invalid key length");
}
}
}
}
internal void SetDecryptionKey (string key)
{
if ((key == null) || key.StartsWith ("AutoGenerate")) {
decryption_key = AutoGenerate (MachineKeyRegistryStorage.KeyType.Encryption);
} else {
try {
decryption_key = MachineKeySectionUtils.GetBytes (key, key.Length);
DecryptionTemplate.Key = decryption_key;
}
catch {
decryption_key = null;
throw new ArgumentException ("Invalid key length");
}
}
}
