/// <summary>
/// Decrypts the symmetric key
/// </summary>
/// <param name="pgpCrypt">PGP asymmetric crypting helper instance</param>
/// <param name="key">The private key to decrypt the symmetric key with</param>
/// <returns>The decrypted, wrapped, symmetric key contained in this packet</returns>
public KeyParameter GetKey(AbstractPgpCrypt pgpCrypt, PgpPrivateKey key)
{
byte[] decrypted = pgpCrypt.ProcessWithLength(false, Get(0), key.Key, out int length);
Array.Resize(ref decrypted, SYM_CRYPT.KeyLengthByte);
if (length > SYM_CRYPT.KeyLengthByte)
{
throw new PgpKeyValidationException("Decryption yielded a result too large for an AES key");
}
else if (length < SYM_CRYPT.KeyLengthByte)
{
//an error happened with leading zeros where they were put at the last place and the processed length was 15
Array.Copy(decrypted, 0, decrypted, 1, length);
decrypted[0] = 0;
}
return(new KeyParameter(decrypted));
}
/// <summary>
/// Constructs a new symmetric key packet
/// </summary>
public SymKeyPacket(byte specifier, KeyParameter key, AbstractPgpCrypt pgpCrypt, PgpPublicKey pgpPublicKey) :
base(specifier, pgpCrypt.Encrypt(key.GetKey(), pgpPublicKey.GetKey()))
{
}
