/// <summary>
        /// Encrypt the specified data using the specified salt.
        ///Encrypt uses provided salt, uses master key
        ///& salt to generate per-data key & nonce with the help of HKDF
        ///Salt is concatenated to the ciphertext
        /// </summary>
        /// <returns>The encrypted data bytes.</returns>
        /// <param name="data">Data to be encrypted.</param>
        public byte[] EncryptWithSalt(byte[] data, byte[] salt)
        {
            Validation.NotNull(data);
            Validation.NotNullOrEmptyByteArray(salt);

            var hkdf = new HkdfBytesGenerator(new Sha512Digest());

            hkdf.Init(new HkdfParameters(this.key, salt, this.domain));

            var keyNonce = new byte[SymKeyLen + SymNonceLen];

            hkdf.GenerateBytes(keyNonce, 0, keyNonce.Length);

            var cipher         = new GcmBlockCipher(new AesEngine());
            var keyNonceSlice1 = ((Span <byte>)keyNonce).Slice(0, SymKeyLen);
            var keyNonceSlice2 = ((Span <byte>)keyNonce).Slice(SymKeyLen);

            var parameters = new AeadParameters(
                new KeyParameter(keyNonceSlice1.ToArray()),
                SymTagLen * 8,
                keyNonceSlice2.ToArray());

            cipher.Init(true, parameters);

            var cipherText = new byte[cipher.GetOutputSize(data.Length)];
            var len        = cipher.ProcessBytes(data, 0, data.Length, cipherText, 0);

            cipher.DoFinal(cipherText, len);

            return(Bytes.Combine(salt, cipherText));
        }
Exemplo n.º 2
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        private byte[] ComputeHkdf(byte[] ikm)
        {
            var generator  = new HkdfBytesGenerator(new Sha256Digest());
            var parameters = new HkdfParameters(ikm, null, HkdfInfo);

            generator.Init(parameters);
            byte[] output = new byte[_hkdfSize];
            generator.GenerateBytes(output, 0, _hkdfSize);
            return(output);
        }
Exemplo n.º 3
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        private HkdfBytesGenerator InitHkdf(byte[] key, byte[] salt, byte[] info)
        {
            Validation.NotNullOrEmptyByteArray(key);
            Validation.NotNullOrEmptyByteArray(info);

            var hkdf = new HkdfBytesGenerator(new Sha512Digest());

            hkdf.Init(new HkdfParameters(key, salt, info));
            return(hkdf);
        }
Exemplo n.º 4
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        void ICryptoLibrary.DeriveKeysRFC5869_32bytes(byte[] input, byte[] salt, out byte[] key1, out byte[] key2)
        {
            var hkdf = new HkdfBytesGenerator(new Sha256Digest());

            hkdf.Init(new HkdfParameters(input, salt, null));

            key1 = new byte[32];
            hkdf.GenerateBytes(key1, 0, key1.Length);
            key2 = new byte[32];
            hkdf.GenerateBytes(key2, 0, key2.Length);
        }
        public static byte[] HKDF(int keylen, byte[] master, byte[] salt, byte[] info)
        {
            byte[]             ret        = new byte[keylen];
            IDigest            degist     = new Sha1Digest();
            HkdfParameters     parameters = new HkdfParameters(master, salt, info);
            HkdfBytesGenerator hkdf       = new HkdfBytesGenerator(degist);

            hkdf.Init(parameters);
            hkdf.GenerateBytes(ret, 0, keylen);
            return(ret);
        }
        // currently useless, just keep api same, again
        public static Span <byte> HKDF(int keylen, Span <byte> master, Span <byte> salt, Span <byte> info)
        {
            byte[]             ret        = new byte[keylen];
            IDigest            degist     = new Sha1Digest();
            HkdfParameters     parameters = new HkdfParameters(master.ToArray(), salt.ToArray(), info.ToArray());
            HkdfBytesGenerator hkdf       = new HkdfBytesGenerator(degist);

            hkdf.Init(parameters);
            hkdf.GenerateBytes(ret, 0, keylen);
            return(ret.AsSpan());
        }
Exemplo n.º 7
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        /// <summary>
        /// Performs HKDF-SHA-256 on the given data and derives <paramref name="numberOfBytes"/> of data.
        /// </summary>
        /// <param name="data">The data HKDF-SHA-256 should be performed on.</param>
        /// <param name="numberOfBytes">How many bytes should be derived.</param>
        public static byte[] HkdfSha256(byte[] data, byte[] salt, string info, int numberOfBytes)
        {
            HkdfBytesGenerator generator = new HkdfBytesGenerator(new Sha256Digest());

            byte[] infoBytes = Encoding.ASCII.GetBytes(info);
            generator.Init(new HkdfParameters(data, salt, infoBytes));

            byte[] result = new byte[numberOfBytes];
            generator.GenerateBytes(result, 0, result.Length);
            return(result);
        }
Exemplo n.º 8
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        private byte[] DeriveKey(string serviceAccountId)
        {
            var generator = new HkdfBytesGenerator(new Sha256Digest());

            generator.Init(HkdfParameters.SkipExtractParameters(mKey, Encoding.UTF8.GetBytes(serviceAccountId)));

            var derivedKey = new byte[derivedKeySize];

            generator.GenerateBytes(derivedKey, 0, derivedKeySize);

            return(derivedKey);
        }
Exemplo n.º 9
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        public static IEnumerable <byte> GenerateAesKey(string sharedKey, IEnumerable <byte> salt)
        {
            var hkdfBytesGenerator = new HkdfBytesGenerator(new Sha256Digest());
            var hkdfParameters     = new HkdfParameters(GetByteFromBase64(sharedKey).ToArray(),
                                                        salt.ToArray(),
                                                        null);

            hkdfBytesGenerator.Init(hkdfParameters);
            var aesKey = new byte[32];

            hkdfBytesGenerator.GenerateBytes(aesKey, 0, 32);
            return(aesKey);
        }
Exemplo n.º 10
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        private static byte[] GeneratePrivateKeyBytes(int numBytes, byte[] masterKeyBytes, long keyIntervalNumber, int counter)
        {
            var keyIntervalBytes = BitConverter.GetBytes(keyIntervalNumber);
            var counterBytes     = BitConverter.GetBytes(counter);
            var ikm     = masterKeyBytes;
            var salt    = keyIntervalBytes.Concat(counterBytes).ToArray();
            var hkdf    = new HkdfBytesGenerator(new Sha256Digest());
            var hParams = new HkdfParameters(ikm, salt, null);

            hkdf.Init(hParams);
            byte[] keyBytes = new byte[numBytes];
            hkdf.GenerateBytes(keyBytes, 0, numBytes);
            return(keyBytes);
        }
Exemplo n.º 11
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        public RemoteAttestationKeys(Curve25519KeyPair keyPair, byte[] serverPublicEphemeral, byte[] serverPublicStatic)
        {
            byte[] ephemeralToEphemeral = Curve25519.getInstance(Curve25519.BEST).calculateAgreement(serverPublicEphemeral, keyPair.getPrivateKey());
            byte[] ephemeralToStatic    = Curve25519.getInstance(Curve25519.BEST).calculateAgreement(serverPublicStatic, keyPair.getPrivateKey());

            byte[] masterSecret = ByteUtil.combine(ephemeralToEphemeral, ephemeralToStatic);
            byte[] publicKeys   = ByteUtil.combine(keyPair.getPublicKey(), serverPublicEphemeral, serverPublicStatic);

            HkdfBytesGenerator generator = new HkdfBytesGenerator(new Sha256Digest());

            generator.Init(new HkdfParameters(masterSecret, publicKeys, null));
            generator.GenerateBytes(ClientKey, 0, ClientKey.Length);
            generator.GenerateBytes(ServerKey, 0, ServerKey.Length);
        }
        public static byte[] X3DhKdf(byte[] input, byte[] info)
        {
            byte[] ikm = ThirtyTwoFFs.Concat(input).ToArray();

            HkdfParameters     parameters = new HkdfParameters(ikm, ThirtyTwoZeros, info);
            HkdfBytesGenerator generator  = new HkdfBytesGenerator(new Sha256Digest());

            generator.Init(parameters);

            byte[] output = new byte[256 / 8];
            generator.GenerateBytes(output, 0, output.Length);

            return(output);
        }
Exemplo n.º 13
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        public ShadowosocksAeadCipher(string password, ValueTuple <int, int> key_salt_size, ILogger logger = null)
            : base(password)
        {
            _keySize_SaltSize = key_salt_size;
            _logger           = logger;

            _hkdf           = new HkdfBytesGenerator(new Sha1Digest());
            _masterKeyBytes = MasterKeyGenerator.PasswordToKey(password, _keySize_SaltSize.Item1);

            _logger?.LogInformation($"ShadowosocksAeadCipher ctor " +
                                    $"_keySize_SaltSize={_keySize_SaltSize.Item1},{_keySize_SaltSize.Item2}");
            _tcpCtx加密 = new TcpCipherContext(_keySize_SaltSize.Item1, _keySize_SaltSize.Item2);
            _tcpCtx解密 = new TcpCipherContext(_keySize_SaltSize.Item1, _keySize_SaltSize.Item2);

            _tcp_decrypt_crumb = SmartBuffer.Rent(LEN_TCP_OVERHEAD_PER_CHUNK * 2);
        }
        // Returns null on HMAC mismatch
        public static byte[] DecryptWithMessageKey(byte[] messageKey, byte[] cipherTextWithHmac, byte[] associatedData = null)
        {
            HkdfParameters     parameters = new HkdfParameters(messageKey, ThirtyTwoZeros, MessageProtocolInfo);
            HkdfBytesGenerator generator  = new HkdfBytesGenerator(new Sha256Digest());

            generator.Init(parameters);

            byte[] encryptionKey     = new byte[32];
            byte[] authenticationKey = new byte[32];
            byte[] iv = new byte[16];

            generator.GenerateBytes(encryptionKey, 0, encryptionKey.Length);
            generator.GenerateBytes(authenticationKey, 0, authenticationKey.Length);
            generator.GenerateBytes(iv, 0, iv.Length);

            return(DecryptWithHmac(new AES256Key(encryptionKey), iv, new AES256Key(authenticationKey), cipherTextWithHmac,
                                   associatedData));
        }
Exemplo n.º 15
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        /// <summary>
        /// Maps arrays of bytes to an integer less than curve's N parameter
        /// </summary>
        private BigInteger HashZ(byte[] domain, params byte[][] datas)
        {
            var hash = this.tupleHash.Sum(domain, datas);

            var hkdf = new HkdfBytesGenerator(new Sha512tDigest(256));

            hkdf.Init(new HkdfParameters(hash, domain, Encoding.UTF8.GetBytes("TupleKDF")));
            var result = new byte[32];

            BigInteger z;

            do
            {
                hkdf.GenerateBytes(result, 0, result.Length);
                z = new BigInteger(1, result);
            }while (z.CompareTo(this.curveParams.N) >= 0);

            return(z);
        }
Exemplo n.º 16
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        /// <summary>
        /// Decrypts the M value for specified password.
        /// </summary>
        public byte[] DecryptM(SecretKey skC, byte[] pwd, byte[] nC, byte[] t1, byte[] c1)
        {
            var t1Point  = this.curve.DecodePoint(t1);
            var c1Point  = this.curve.DecodePoint(c1);
            var hc1Point = this.HashToPoint(dhc1, nC, pwd);
            var minusY   = this.curveParams.N.Neg(skC.Value);

            var mPoint = t1Point.Add(c1Point.Negate()).Add(hc1Point.Multiply(minusY)).Multiply(skC.Value.ModInverse(this.curveParams.N));


            var hkdf = new HkdfBytesGenerator(new Sha512tDigest(256));

            hkdf.Init(new HkdfParameters(mPoint.GetEncoded(), null, Encoding.UTF8.GetBytes("Secret")));
            var key = new byte[32];

            hkdf.GenerateBytes(key, 0, key.Length);

            return(key);
        }
        // Returns a tuple of (new root key, new chain key)
        public static (byte[], byte[]) RatchetRootKey(byte[] rootKey, byte[] dhOutput)
        {
            HkdfParameters     parameters = new HkdfParameters(dhOutput, rootKey, RkRatchetProtocolInfo);
            HkdfBytesGenerator generator  = new HkdfBytesGenerator(new Sha256Digest());

            generator.Init(parameters);

            byte[] newRootKey = new byte[rootKey.Length];
            generator.GenerateBytes(newRootKey, 0, newRootKey.Length);

            HkdfParameters parameters2 = new HkdfParameters(dhOutput, rootKey, CkRatchetProtocolInfo);

            generator.Init(parameters2);

            byte[] newChainKey = new byte[rootKey.Length];
            generator.GenerateBytes(newChainKey, 0, newChainKey.Length);

            return(newRootKey, newChainKey);
        }
        public void HkdfGenerateBytes_Should_GenerateExpectedValue()
        {
            var expectedValue =
                "0F097707AAB66A4CD5FCC79CEB96FB4B99DE2E73DF09295E" +
                "CFF6F6CC7C1DCF169D51B62999BC206487800E8DD451518FA6C50F5C053B8B780208BE7164D3A7F2";
            var arr1 = new byte[] { 0x00, 0x01, 0x02 };
            var arr2 = new byte[] { 0x10, 0x11, 0x12, 0x13, 0x14, 0x15 };
            var arr3 = new byte[] { 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28 };

            var domain = Bytes.FromString("My Tuple App");
            var sha512 = new SHA512Helper();
            var key    = sha512.ComputeHash(null, arr1, arr2, arr3);

            var hkdf = new HkdfBytesGenerator(new Sha512Digest());
            var phe  = new PheCrypto();

            hkdf.Init(new HkdfParameters(key, domain, Domains.KdfInfoZ));
            var resultValue = new byte[64];

            hkdf.GenerateBytes(resultValue, 0, resultValue.Length);

            Assert.Equal(expectedValue, Bytes.ToString(resultValue, StringEncoding.HEX).ToUpper());
        }
        /// <summary>
        /// Decrypt the specified cipherText.
        ///Decrypt extracts 32 byte salt, derives key & nonce and
        ///decrypts ciphertext with the help of HKDF
        /// </summary>
        /// <returns>The decrypted data bytes.</returns>
        /// <param name="cipherText">Encrypted data to be decrypted.</param>
        public byte[] Decrypt(byte[] cipherText)
        {
            Validation.NotNullOrEmptyByteArray(cipherText);

            if (cipherText.Length < (SymSaltLen + SymTagLen))
            {
                throw new ArgumentException("Invalid ciphertext length.");
            }

            var salt = ((Span <byte>)cipherText).Slice(0, SymSaltLen).ToArray();

            var hkdf = new HkdfBytesGenerator(new Sha512Digest());

            hkdf.Init(new HkdfParameters(this.key, salt, this.domain));

            var keyNonce = new byte[SymKeyLen + SymNonceLen];

            hkdf.GenerateBytes(keyNonce, 0, keyNonce.Length);

            var cipher         = new GcmBlockCipher(new AesEngine());
            var keyNonceSlice1 = ((Span <byte>)keyNonce).Slice(0, SymKeyLen);
            var keyNonceSlice2 = ((Span <byte>)keyNonce).Slice(SymKeyLen);

            var parameters = new AeadParameters(new KeyParameter(keyNonceSlice1.ToArray()), SymTagLen * 8, keyNonceSlice2.ToArray());

            cipher.Init(false, parameters);

            var cipherTextExceptSalt = ((Span <byte>)cipherText).Slice(SymSaltLen).ToArray();
            var plainText            = new byte[cipher.GetOutputSize(cipherTextExceptSalt.Length)];

            var len = cipher.ProcessBytes(cipherTextExceptSalt, 0, cipherTextExceptSalt.Length, plainText, 0);

            cipher.DoFinal(plainText, len);

            return(plainText);
        }
Exemplo n.º 20
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        public override void PerformTest()
        {
            {
                // === A.1. Test Case 1 - Basic test case with SHA-256 ===

                IDigest hash = new Sha256Digest();
                byte[]  ikm  = Hex.Decode("0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b");
                byte[]  salt = Hex.Decode("000102030405060708090a0b0c");
                byte[]  info = Hex.Decode("f0f1f2f3f4f5f6f7f8f9");
                int     l    = 42;
                byte[]  okm  = new byte[l];

                HkdfParameters parameters = new HkdfParameters(ikm, salt, info);

                HkdfBytesGenerator hkdf = new HkdfBytesGenerator(hash);
                hkdf.Init(parameters);
                hkdf.GenerateBytes(okm, 0, l);

                CompareOkm(1, okm, Hex.Decode(
                               "3cb25f25faacd57a90434f64d0362f2a" +
                               "2d2d0a90cf1a5a4c5db02d56ecc4c5bf" +
                               "34007208d5b887185865"));
            }

            // === A.2. Test Case 2 - Test with SHA-256 and longer inputs/outputs
            // ===
            {
                IDigest hash = new Sha256Digest();
                byte[]  ikm  = Hex.Decode("000102030405060708090a0b0c0d0e0f"
                                          + "101112131415161718191a1b1c1d1e1f"
                                          + "202122232425262728292a2b2c2d2e2f"
                                          + "303132333435363738393a3b3c3d3e3f"
                                          + "404142434445464748494a4b4c4d4e4f");
                byte[] salt = Hex.Decode("606162636465666768696a6b6c6d6e6f"
                                         + "707172737475767778797a7b7c7d7e7f"
                                         + "808182838485868788898a8b8c8d8e8f"
                                         + "909192939495969798999a9b9c9d9e9f"
                                         + "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf");
                byte[] info = Hex.Decode("b0b1b2b3b4b5b6b7b8b9babbbcbdbebf"
                                         + "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"
                                         + "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf"
                                         + "e0e1e2e3e4e5e6e7e8e9eaebecedeeef"
                                         + "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff");
                int    l   = 82;
                byte[] okm = new byte[l];

                HkdfParameters parameters = new HkdfParameters(ikm, salt, info);

                HkdfBytesGenerator hkdf = new HkdfBytesGenerator(hash);
                hkdf.Init(parameters);
                hkdf.GenerateBytes(okm, 0, l);

                CompareOkm(2, okm, Hex.Decode(
                               "b11e398dc80327a1c8e7f78c596a4934" +
                               "4f012eda2d4efad8a050cc4c19afa97c" +
                               "59045a99cac7827271cb41c65e590e09" +
                               "da3275600c2f09b8367793a9aca3db71" +
                               "cc30c58179ec3e87c14c01d5c1f3434f" +
                               "1d87"));
            }

            {
                // === A.3. Test Case 3 - Test with SHA-256 and zero-length
                // salt/info ===

                // setting salt to an empty byte array means that the salt is set to
                // HashLen zero valued bytes
                // setting info to null generates an empty byte array as info
                // structure

                IDigest hash = new Sha256Digest();
                byte[]  ikm  = Hex.Decode("0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b");
                byte[]  salt = new byte[0];
                byte[]  info = null;
                int     l    = 42;
                byte[]  okm  = new byte[l];

                HkdfParameters parameters = new HkdfParameters(ikm, salt, info);

                HkdfBytesGenerator hkdf = new HkdfBytesGenerator(hash);
                hkdf.Init(parameters);
                hkdf.GenerateBytes(okm, 0, l);

                CompareOkm(3, okm, Hex.Decode(
                               "8da4e775a563c18f715f802a063c5a31" +
                               "b8a11f5c5ee1879ec3454e5f3c738d2d" +
                               "9d201395faa4b61a96c8"));
            }

            {
                // === A.4. Test Case 4 - Basic test case with SHA-1 ===

                IDigest hash = new Sha1Digest();
                byte[]  ikm  = Hex.Decode("0b0b0b0b0b0b0b0b0b0b0b");
                byte[]  salt = Hex.Decode("000102030405060708090a0b0c");
                byte[]  info = Hex.Decode("f0f1f2f3f4f5f6f7f8f9");
                int     l    = 42;
                byte[]  okm  = new byte[l];

                HkdfParameters parameters = new HkdfParameters(ikm, salt, info);

                HkdfBytesGenerator hkdf = new HkdfBytesGenerator(hash);
                hkdf.Init(parameters);
                hkdf.GenerateBytes(okm, 0, l);

                CompareOkm(4, okm, Hex.Decode(
                               "085a01ea1b10f36933068b56efa5ad81" +
                               "a4f14b822f5b091568a9cdd4f155fda2" +
                               "c22e422478d305f3f896"));
            }

            // === A.5. Test Case 5 - Test with SHA-1 and longer inputs/outputs ===
            {
                IDigest hash = new Sha1Digest();
                byte[]  ikm  = Hex.Decode("000102030405060708090a0b0c0d0e0f"
                                          + "101112131415161718191a1b1c1d1e1f"
                                          + "202122232425262728292a2b2c2d2e2f"
                                          + "303132333435363738393a3b3c3d3e3f"
                                          + "404142434445464748494a4b4c4d4e4f");
                byte[] salt = Hex.Decode("606162636465666768696a6b6c6d6e6f"
                                         + "707172737475767778797a7b7c7d7e7f"
                                         + "808182838485868788898a8b8c8d8e8f"
                                         + "909192939495969798999a9b9c9d9e9f"
                                         + "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf");
                byte[] info = Hex.Decode("b0b1b2b3b4b5b6b7b8b9babbbcbdbebf"
                                         + "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"
                                         + "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf"
                                         + "e0e1e2e3e4e5e6e7e8e9eaebecedeeef"
                                         + "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff");
                int    l   = 82;
                byte[] okm = new byte[l];

                HkdfParameters parameters = new HkdfParameters(ikm, salt, info);

                HkdfBytesGenerator hkdf = new HkdfBytesGenerator(hash);
                hkdf.Init(parameters);
                hkdf.GenerateBytes(okm, 0, l);

                CompareOkm(5, okm, Hex.Decode(
                               "0bd770a74d1160f7c9f12cd5912a06eb" +
                               "ff6adcae899d92191fe4305673ba2ffe" +
                               "8fa3f1a4e5ad79f3f334b3b202b2173c" +
                               "486ea37ce3d397ed034c7f9dfeb15c5e" +
                               "927336d0441f4c4300e2cff0d0900b52" +
                               "d3b4"));
            }

            {
                // === A.6. Test Case 6 - Test with SHA-1 and zero-length salt/info
                // ===

                // setting salt to null should generate a new salt of HashLen zero
                // valued bytes

                IDigest hash = new Sha1Digest();
                byte[]  ikm  = Hex.Decode("0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b");
                byte[]  salt = null;
                byte[]  info = new byte[0];
                int     l    = 42;
                byte[]  okm  = new byte[l];

                HkdfParameters parameters = new HkdfParameters(ikm, salt, info);

                HkdfBytesGenerator hkdf = new HkdfBytesGenerator(hash);
                hkdf.Init(parameters);
                hkdf.GenerateBytes(okm, 0, l);

                CompareOkm(6, okm, Hex.Decode(
                               "0ac1af7002b3d761d1e55298da9d0506" +
                               "b9ae52057220a306e07b6b87e8df21d0" +
                               "ea00033de03984d34918"));
            }

            {
                // === A.7. Test Case 7 - Test with SHA-1, salt not provided,
                // zero-length info ===
                // (salt defaults to HashLen zero octets)

                // this test is identical to test 6 in all ways bar the IKM value

                IDigest hash = new Sha1Digest();
                byte[]  ikm  = Hex.Decode("0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c");
                byte[]  salt = null;
                byte[]  info = new byte[0];
                int     l    = 42;
                byte[]  okm  = new byte[l];

                HkdfParameters parameters = new HkdfParameters(ikm, salt, info);

                HkdfBytesGenerator hkdf = new HkdfBytesGenerator(hash);
                hkdf.Init(parameters);
                hkdf.GenerateBytes(okm, 0, l);

                CompareOkm(7, okm, Hex.Decode(
                               "2c91117204d745f3500d636a62f64f0a" +
                               "b3bae548aa53d423b0d1f27ebba6f5e5" +
                               "673a081d70cce7acfc48"));
            }

            {
                // === A.101. Additional Test Case - Test with SHA-1, skipping extract
                // zero-length info ===
                // (salt defaults to HashLen zero octets)

                // this test is identical to test 7 in all ways bar the IKM value
                // which is set to the PRK value

                IDigest hash = new Sha1Digest();
                byte[]  ikm  = Hex.Decode("2adccada18779e7c2077ad2eb19d3f3e731385dd");
                byte[]  info = new byte[0];
                int     l    = 42;
                byte[]  okm  = new byte[l];

                HkdfParameters parameters = HkdfParameters.SkipExtractParameters(ikm, info);

                HkdfBytesGenerator hkdf = new HkdfBytesGenerator(hash);
                hkdf.Init(parameters);
                hkdf.GenerateBytes(okm, 0, l);

                CompareOkm(101, okm, Hex.Decode(
                               "2c91117204d745f3500d636a62f64f0a" +
                               "b3bae548aa53d423b0d1f27ebba6f5e5" +
                               "673a081d70cce7acfc48"));
            }

            {
                // === A.102. Additional Test Case - Test with SHA-1, maximum output ===
                // (salt defaults to HashLen zero octets)

                // this test is identical to test 7 in all ways bar the IKM value

                IDigest hash = new Sha1Digest();
                byte[]  ikm  = Hex.Decode("2adccada18779e7c2077ad2eb19d3f3e731385dd");
                byte[]  info = new byte[0];
                int     l    = 255 * hash.GetDigestSize();
                byte[]  okm  = new byte[l];

                HkdfParameters parameters = HkdfParameters.SkipExtractParameters(ikm, info);

                HkdfBytesGenerator hkdf = new HkdfBytesGenerator(hash);
                hkdf.Init(parameters);
                hkdf.GenerateBytes(okm, 0, l);

                int zeros = 0;
                for (int i = 0; i < hash.GetDigestSize(); i++)
                {
                    if (okm[i] == 0)
                    {
                        zeros++;
                    }
                }

                if (zeros == hash.GetDigestSize())
                {
                    Fail("HKDF failed generator test " + 102);
                }
            }
        }