private static byte[] DecryptBytes(Compact.Iterator parts, object key, JweAlgorithm?jweAlg, JweEncryption?jweEnc, JwtSettings settings = null)
{
byte[] header = parts.Next();
byte[] encryptedCek = parts.Next();
byte[] iv = parts.Next();
byte[] cipherText = parts.Next();
byte[] authTag = parts.Next();
JwtSettings jwtSettings = GetSettings(settings);
IDictionary <string, object> jwtHeader = jwtSettings.JsonMapper.Parse <Dictionary <string, object> >(Encoding.UTF8.GetString(header));
JweAlgorithm headerAlg = jwtSettings.JwaAlgorithmFromHeader((string)jwtHeader["alg"]);
JweEncryption headerEnc = jwtSettings.JweAlgorithmFromHeader((string)jwtHeader["enc"]);
IKeyManagement keys = jwtSettings.Jwa(headerAlg);
IJweAlgorithm enc = jwtSettings.Jwe(headerEnc);
if (keys == null)
{
throw new JoseException(string.Format("Unsupported JWA algorithm requested: {0}", headerAlg));
}
if (enc == null)
{
throw new JoseException(string.Format("Unsupported JWE algorithm requested: {0}", headerEnc));
}
if (jweAlg != null && (JweAlgorithm)jweAlg != headerAlg)
{
throw new InvalidAlgorithmException("The algorithm type passed to the Decrypt method did not match the algorithm type in the header.");
}
if (jweEnc != null && (JweEncryption)jweEnc != headerEnc)
{
throw new InvalidAlgorithmException("The encryption type passed to the Decrypt method did not match the encryption type in the header.");
}
byte[] cek = keys.Unwrap(encryptedCek, key, enc.KeySize, jwtHeader);
byte[] aad = Encoding.UTF8.GetBytes(Compact.Serialize(header));
byte[] plainText = enc.Decrypt(aad, cek, iv, cipherText, authTag);
if (jwtHeader.ContainsKey("zip"))
{
ICompression compression = jwtSettings.Compression((string)jwtHeader["zip"]);
plainText = compression.Decompress(plainText);
}
return(plainText);
}
/// <summary>
/// Encodes given binary data to JWT token and applies requested encryption/compression algorithms.
/// </summary>
/// <param name="payload">Binary data to encode (not null)</param>
/// <param name="key">key for encryption, suitable for provided JWS algorithm, can be null.</param>
/// <param name="alg">JWT algorithm to be used.</param>
/// <param name="enc">encryption algorithm to be used.</param>
/// <param name="compression">optional compression type to use.</param>
/// <param name="extraHeaders">optional extra headers to pass along with the payload.</param>
/// <param name="settings">optional settings to override global DefaultSettings</param>
/// <returns>JWT in compact serialization form, encrypted and/or compressed.</returns>
public static string EncodeBytes(byte[] payload, object key, JweAlgorithm alg, JweEncryption enc, JweCompression?compression = null, IDictionary <string, object> extraHeaders = null, JwtSettings settings = null)
{
if (payload == null)
{
throw new ArgumentNullException(nameof(payload));
}
JwtSettings jwtSettings = GetSettings(settings);
IKeyManagement keys = jwtSettings.Jwa(alg);
IJweAlgorithm _enc = jwtSettings.Jwe(enc);
if (keys == null)
{
throw new JoseException(string.Format("Unsupported JWA algorithm requested: {0}", alg));
}
if (_enc == null)
{
throw new JoseException(string.Format("Unsupported JWE algorithm requested: {0}", enc));
}
IDictionary <string, object> jwtHeader = new Dictionary <string, object> {
{ "alg", jwtSettings.JwaHeaderValue(alg) }, { "enc", jwtSettings.JweHeaderValue(enc) }
};
Dictionaries.Append(jwtHeader, extraHeaders);
byte[][] contentKeys = keys.WrapNewKey(_enc.KeySize, key, jwtHeader);
byte[] cek = contentKeys[0];
byte[] encryptedCek = contentKeys[1];
if (compression.HasValue)
{
jwtHeader["zip"] = jwtSettings.CompressionHeader(compression.Value);
payload = jwtSettings.Compression(compression.Value).Compress(payload);
}
byte[] header = Encoding.UTF8.GetBytes(jwtSettings.JsonMapper.Serialize(jwtHeader));
byte[] aad = Encoding.UTF8.GetBytes(Compact.Serialize(header));
byte[][] encParts = _enc.Encrypt(aad, payload, cek);
return(Compact.Serialize(header, encryptedCek, encParts[0], encParts[1], encParts[2]));
}