public string Decrypt(ProtectedMemory key, string message)
{
Blake2bProtectedCryptoProvider blake2b = new Blake2bProtectedCryptoProvider();
using ProtectedMemory paddedKey = blake2b.ComputeHashProtected(key, 64);
ExtractHeader(message, paddedKey, out byte[] iv, out byte[] buffer);
using (ProtectedMemory aesKey = DeriveAesKey(paddedKey))
{
AesState aesState = new AesState(aesKey, iv);
aesState.AesCbcDecryptBuffer(ref buffer);
}
int contentLength = Pkcs7Padding.GetContentLength(buffer, 16);
return(Encoding.UTF8.GetString(buffer, 0, contentLength));
}
public ProtectedMemory DecryptProtected(ProtectedMemory key, string message)
{
Blake2bProtectedCryptoProvider blake2b = new Blake2bProtectedCryptoProvider();
using ProtectedMemory paddedKey = blake2b.ComputeHashProtected(key, 64);
ExtractHeader(message, paddedKey, out byte[] iv, out byte[] messageBytes);
using ProtectedMemory protectedBuffer = ProtectedMemory.Allocate(messageBytes.Length);
protectedBuffer.Write(messageBytes, 0, messageBytes.Length);
using (ProtectedMemory aesKey = DeriveAesKey(paddedKey))
{
AesState aesState = new AesState(aesKey, iv);
aesState.AesCbcDecryptBuffer(protectedBuffer);
}
int contentLength = Pkcs7Padding.GetContentLength(protectedBuffer, 16);
ProtectedMemory result = ProtectedMemory.Allocate(contentLength);
protectedBuffer.CopyTo(0, result, 0, contentLength);
return(result);
}
