private static byte[] DecryptBytes(byte[][] parts, object key, JweAlgorithm?jweAlg, JweEncryption?jweEnc, JwtSettings settings = null) { byte[] header = parts[0]; byte[] encryptedCek = parts[1]; byte[] iv = parts[2]; byte[] cipherText = parts[3]; byte[] authTag = parts[4]; 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")) { var alg = (string)jwtHeader["zip"]; var compression = jwtSettings.Compression(GetJweCompression(alg)); if (compression == null) { throw new JoseException(string.Format("Unsupported compressions algorithm requested: {0}", alg)); } 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) { // https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/nameof // nameof is not defined prior to c# 6.0 spec // throw new ArgumentNullException(nameof(payload)); throw new ArgumentNullException("payload is null"); } 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])); }
/// <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="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"] = JweCompressionMethods[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])); }
/// <summary> /// Encrypts given binary plaintext using JWE and applies requested encryption/compression algorithms. /// </summary> /// <param name="plaintext">Binary data to encrypt (not null)</param> /// <param name="recipients">The details of who to encrypt the plaintext (or rather the CEK) to.</param> /// <param name="enc">encryption algorithm to be used to encrypt the plaintext.</param> /// <param name="aad">additional authentication data (SerializationMode.Json only)</param> /// <param name="mode">serialization mode to use. Note only one recipient can be specified for compact and flattened json serialization.</param> /// <param name="compression">optional compression type to use.</param> /// <param name="extraProtectedHeaders">optional extra headers to put in the protected header.</param> /// <param name="unprotectedHeaders">optional unprotected headers</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 EncryptBytes(byte[] plaintext, IEnumerable <JweRecipient> recipients, JweEncryption enc, byte[] aad = null, SerializationMode mode = SerializationMode.Json, JweCompression?compression = null, IDictionary <string, object> extraProtectedHeaders = null, IDictionary <string, object> unprotectedHeaders = null, JwtSettings settings = null) { if (plaintext == null) { throw new ArgumentNullException(nameof(plaintext)); } settings = GetSettings(settings); IJweAlgorithm _enc = settings.Jwe(enc); if (_enc == null) { throw new JoseException(string.Format("Unsupported JWE enc requested: {0}", enc)); } IDictionary <string, object> joseProtectedHeader = Dictionaries.MergeHeaders( new Dictionary <string, object> { { "enc", settings.JweHeaderValue(enc) } }, extraProtectedHeaders); byte[] cek = null; var recipientsOut = new List <JweRecipient>(); foreach (var recipient in recipients) { IKeyManagement keys = settings.Jwa(recipient.Alg); if (keys == null) { throw new JoseException(string.Format("Unsupported JWE alg requested: {0}", recipient.Alg)); } // joseHeader - is merge of headers // - key management will read from (e.g. enc,apv,apu - ECDH-ES) // - key management will write to (e.g. iv, tag - AesGcmKW) IDictionary <string, object> joseHeader = Dictionaries.MergeHeaders( joseProtectedHeader, new Dictionary <string, object> { { "alg", settings.JwaHeaderValue(recipient.Alg) } }, recipient.Header, unprotectedHeaders ); byte[] encryptedCek; if (cek == null) { byte[][] contentKeys = keys.WrapNewKey(_enc.KeySize, recipient.Key, joseHeader); cek = contentKeys[0]; encryptedCek = contentKeys[1]; } else { encryptedCek = keys.WrapKey(cek, recipient.Key, joseHeader); } // For the per-receipient header we want the headers from the result of IKeyManagements key wrapping but without the // shared headers IDictionary <string, object> recipientHeader = joseHeader .Where( kvp => !joseProtectedHeader.ContainsKey(kvp.Key) && (unprotectedHeaders == null || !unprotectedHeaders.ContainsKey(kvp.Key)) ) .ToDictionary(kvp => kvp.Key, kvp => kvp.Value); recipientsOut.Add(new JweRecipient(encryptedCek, recipientHeader)); } if (compression.HasValue) { joseProtectedHeader["zip"] = settings.CompressionHeader(compression.Value); plaintext = settings.Compression(compression.Value).Compress(plaintext); } switch (mode) { case SerializationMode.Compact: { if (recipientsOut.Count != 1) { throw new JoseException("Only one recipient is supported by the JWE Compact Serialization."); } if (aad != null) { throw new JoseException("JWE AAD value is not valid for JWE Compact Serialization."); } joseProtectedHeader = Dictionaries.MergeHeaders(recipientsOut[0].Header, joseProtectedHeader); byte[] header = Encoding.UTF8.GetBytes(settings.JsonMapper.Serialize(joseProtectedHeader)); aad = Encoding.UTF8.GetBytes(Compact.Serialize(header)); byte[][] encParts = _enc.Encrypt(aad, plaintext, cek); return(new JweToken( header, null, recipientsOut, null, encParts[0], encParts[1], encParts[2], mode) .AsString()); } case SerializationMode.Json: { var protectedHeaderBytes = Encoding.UTF8.GetBytes(settings.JsonMapper.Serialize(joseProtectedHeader)); byte[] asciiEncodedProtectedHeader = Encoding.ASCII.GetBytes(Base64Url.Encode(protectedHeaderBytes)); byte[][] encParts = _enc.Encrypt(Aad(protectedHeaderBytes, aad), plaintext, cek); return(new JweToken( protectedHeaderBytes, unprotectedHeaders, recipientsOut, aad, encParts[0], encParts[1], encParts[2], mode) .AsString(settings.JsonMapper)); } default: throw new JoseException($"Unsupported serializtion mode: {mode}."); } }
/// <summary> /// Decypts a JWE by performing necessary decompression/decryption and authenticated decryption as defined in RFC7516. /// </summary> /// <param name="jwe">JWE to decrypt.</param> /// <param name="key">key for decoding suitable for JWE algorithm used to encrypt the CEK.</param> /// <param name="expectedJweAlg">The algorithm type that we expect to receive in the header.</param> /// <param name="expectedJweEnc">The encryption type that we expect to receive in the header.</param> /// <param name="settings">optional settings to override global DefaultSettings</param> /// <returns>Decrypted JweToken object</returns> /// <exception cref="IntegrityException">if AEAD operation validation failed</exception> /// <exception cref="EncryptionException">if JWE can't be decrypted</exception> /// <exception cref="InvalidAlgorithmException">if encryption or compression algorithm is not supported</exception> public static JweToken Decrypt(string jwe, object key, JweAlgorithm?expectedJweAlg = null, JweEncryption?expectedJweEnc = null, JwtSettings settings = null) { Ensure.IsNotEmpty(jwe, "Incoming jwe expected to be in a valid serialization form, not empty, whitespace or null."); settings = GetSettings(settings); JweToken token = Headers(jwe); if (token.ProtectedHeaderBytes == null && token.Encoding == SerializationMode.Compact) { throw new JoseException(string.Format("Protected header was missing but required with compact encoding.")); } var exceptions = new List <Exception>(); foreach (var recipient in token.Recipients) { var headerAlg = settings.JwaAlgorithmFromHeader((string)recipient.JoseHeader["alg"]); var encryptedCek = recipient.EncryptedCek; // skip recipient if asked to do strict validation if (expectedJweAlg != null && expectedJweAlg != headerAlg) { continue; } IKeyManagement keys = settings.Jwa(headerAlg); if (keys == null) { throw new JoseException(string.Format("Unsupported JWA algorithm requested: {0}", headerAlg)); } try { JweEncryption headerEnc = settings.JweAlgorithmFromHeader((string)recipient.JoseHeader["enc"]); IJweAlgorithm enc = settings.Jwe(headerEnc); if (enc == null) { throw new JoseException(string.Format("Unsupported JWE algorithm requested: {0}", headerEnc)); } if (expectedJweEnc != null && expectedJweEnc != 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(recipient.EncryptedCek, key, enc.KeySize, recipient.JoseHeader); byte[] plaintext = enc.Decrypt(Aad(token.ProtectedHeaderBytes, token.Aad), cek, token.Iv, token.Ciphertext, token.AuthTag); if (recipient.JoseHeader.TryGetValue("zip", out var compressionAlg)) { var compression = settings.Compression((string)compressionAlg); plaintext = compression.Decompress(plaintext); } token.PlaintextBytes = plaintext; token.Recipient = recipient; return(token); } catch (ArgumentException ex) { exceptions.Add(ex); } catch (JoseException ex) { exceptions.Add(ex); } } // nobody was eligable for decryption if (exceptions.Count == 0) { throw new InvalidAlgorithmException("The algorithm type passed to the Decrypt method did not match the algorithm type in the header."); } // decryption failed if (exceptions.Select(e => new KeyValuePair <Type, String>(e.GetType(), e.Message)).Distinct().Count() == 1) { // throw the first throw exceptions[0]; } else { throw new JoseException($"No recipients able to decrypt.", new AggregateException(exceptions)); } }