public AES(AesKeySize keySize, string key, string iv)
{
algorithm = new AesCryptoServiceProvider();
algorithm.KeySize = (int)keySize;
Initialize(key, iv, CipherMode.CBC);
}
public AesKey GenerateAesKey(AesKeySize keySizeInBits)
{
return(new AesKey()
{
Key = GetRandomStr((int)keySizeInBits / 8), //xx bytes = xx * 8 bit
IV = GetRandomStr(16) //16 bytes = 128bit
});
}
public void GenerateAesKeyTest(AesKeySize keySize)
{
AesKeyInfo encryptionKeyInfo = AesProvider.GenerateKey(keySize);
Assert.NotNull(encryptionKeyInfo.Key);
Assert.NotNull(encryptionKeyInfo.IV);
Assert.Equal((int)keySize / 8, encryptionKeyInfo.Key.Length);
}
/// <summary>
/// Decrypts the given encrypted text (cipher text) using the given key and key size.
/// </summary>
/// <param name="cipherText">The encrypted text to decrypt</param>
/// <param name="key">The (HEXADECIMAL) key used to encrypt the text and that will be used to decrypt it</param>
/// <param name="keySize">The size of the key for the creation of the cipher</param>
public CommandResult <string> Decrypt(string cipherText, string key, AesKeySize keySize)
{
if (String.IsNullOrWhiteSpace(cipherText))
{
return(CommandResultFactory.Fail("There was no text given to decrypt", (string)null));
}
if (String.IsNullOrWhiteSpace(key))
{
return(CommandResultFactory.Fail("Could not decrypt the text. The given key was null or empty.", (string)null));
}
try
{
CommandResult <string> result;
using (var aesCipher = Aes.Create())
{
result = SetupCipher(aesCipher, key, keySize)
.Then(aes =>
{
var splitCipher = cipherText.Split('_');
if (splitCipher.Length != 2)
{
return(CommandResultFactory.Fail("The given cipher text was not in the correct encrypted format for decryption",
(string)null));
}
var initVector = splitCipher[0];
var encryptedString = splitCipher[1];
if (initVector.Length % 2 != 0 || encryptedString.Length % 2 != 0)
{
return(CommandResultFactory.Fail("The given cipher text was not in the correct encrypted format for decryption",
(string)null));
}
aes.IV = initVector.ToHexBytes();
var cryptoTransform = aes.CreateDecryptor();
var cipherBytes = encryptedString.ToHexBytes();
if (cipherBytes == null)
{
return(CommandResultFactory.Fail(
"The encrypted string could not be converted into a Hexadecimal Byte Array and therefore could not be decrypted.",
(string)null));
}
var resultTextBytes = cryptoTransform.TransformFinalBlock(cipherBytes, 0, cipherBytes.Length);
var resultText = resultTextBytes.ToUTF8String();
return(resultText == null
? CommandResultFactory.Fail("Could not convert the decrypted bytes into a string.", (string)null)
: CommandResultFactory.Ok <string>(resultText));
});
}
return(result);
}
catch (Exception e)
{
var message = $"An exception was thrown while trying to decrypt the text. It is as follows:\n{e.Message}";
return(CommandResultFactory.Fail(message, (string)null));
}
}
private ICryptoTransform CreateDecryptor(byte[] key, AesKeySize keySize = AesKeySize.Aes128, PaddingMode paddingMode = PaddingMode.PKCS7)
{
Aes aes = new Aes(key.Copy(), keySize);
aes.PaddingMode = paddingMode;
aes.RemovePaddingFunction = PaddingFactory.GetRemovePaddingFunction(paddingMode);
aes.InitializeRoundKey();
return(new AesDecryptor(aes));
}
private void ExecuteAesEncryptionTest <TContext>(AesKeySize aesKeyType) where TContext : DatabaseContext
{
AesKeyInfo encryptionKeyInfo = AesProvider.GenerateKey(aesKeyType);
var provider = new AesProvider(encryptionKeyInfo.Key, encryptionKeyInfo.IV, CipherMode.CBC, PaddingMode.Zeros);
var author = new AuthorEntity("John", "Doe", 42)
{
Books = new List <BookEntity>()
{
new BookEntity("Lorem Ipsum", 300),
new BookEntity("Dolor sit amet", 390)
}
};
string authorEncryptedFirstName = provider.Encrypt(author.FirstName);
string authorEncryptedLastName = provider.Encrypt(author.LastName);
string firstBookEncryptedName = provider.Encrypt(author.Books.First().Name);
string lastBookEncryptedName = provider.Encrypt(author.Books.Last().Name);
using (var contextFactory = new DatabaseContextFactory())
{
// Save data to an encrypted database context
using (var dbContext = contextFactory.CreateContext <TContext>(provider))
{
dbContext.Authors.Add(author);
dbContext.SaveChanges();
}
// Read encrypted data from normal context and compare with encrypted data.
using (var dbContext = contextFactory.CreateContext <DatabaseContext>())
{
var authorFromDb = dbContext.Authors.Include(x => x.Books).FirstOrDefault();
Assert.NotNull(authorFromDb);
Assert.Equal(authorEncryptedFirstName, authorFromDb.FirstName);
Assert.Equal(authorEncryptedLastName, authorFromDb.LastName);
Assert.NotNull(authorFromDb.Books);
Assert.NotEmpty(authorFromDb.Books);
Assert.Equal(2, authorFromDb.Books.Count);
Assert.Equal(firstBookEncryptedName, authorFromDb.Books.First().Name);
Assert.Equal(lastBookEncryptedName, authorFromDb.Books.Last().Name);
}
// Read decrypted data and compare with original data
using (var dbContext = contextFactory.CreateContext <TContext>(provider))
{
var authorFromDb = dbContext.Authors.Include(x => x.Books).FirstOrDefault();
Assert.NotNull(authorFromDb);
Assert.Equal(author.FirstName, authorFromDb.FirstName);
Assert.Equal(author.LastName, authorFromDb.LastName);
Assert.NotNull(authorFromDb.Books);
Assert.NotEmpty(authorFromDb.Books);
Assert.Equal(2, authorFromDb.Books.Count);
Assert.Equal(author.Books.First().Name, authorFromDb.Books.First().Name);
Assert.Equal(author.Books.Last().Name, authorFromDb.Books.Last().Name);
}
}
}
public static ICryptoTransform CreateEncryptor(byte[] key, byte[] IV, AesKeySize keySize = AesKeySize.Aes128, PaddingMode paddingMode = PaddingMode.PKCS7)
{
Aes aes = new Aes(key.Copy(), IV.Copy(), keySize);
aes.PaddingMode = paddingMode;
aes.PaddingFunction = PaddingFactory.GetPaddingFunction(paddingMode);
aes.EncryptMode = EncryptModeEnum.CBC;
aes.InitializeRoundKey();
return(new AesCBCEncryptor(aes));
}
public Aes(byte[] byteKey, AesKeySize keySize = AesKeySize.Aes128)
{
this.KeySize = keySize;
int kSz = GetKeySize();
if (kSz != byteKey.Length)
{
throw new ArgumentException($"Key length not equal {kSz}");
}
ByteKey = byteKey;
}
private static Aes CreateAesGcm(byte[] key, byte[] IV, AesKeySize keySize)
{
byte[] newIV = new byte[IV.Length];
Array.Copy(IV, 0, newIV, 0, IV.Length);
Aes aes = new Aes(key.Copy(), newIV, keySize);
aes.PaddingMode = PaddingMode.None;
aes.EncryptMode = EncryptModeEnum.GCM;
aes.InitializeRoundKey();
return(aes);
}
/// <summary>
/// Decrypts the cipher text by using the given key material, key size, and block size.
/// </summary>
/// <param name="cipherText">Encrypted text for decryption</param>
/// <param name="key">The (HEXADECIMAL) key used for decryption</param>
/// <param name="keySize">size of key used in the cipher creation</param>
/// <param name="blockSize">block size used in the creation of the cipher</param>
/// <returns></returns>
public CommandResult <string> CustomDecrypt(string cipherText, string key, AesKeySize keySize, BlockSize blockSize)
{
if (String.IsNullOrWhiteSpace(cipherText))
{
return(CommandResultFactory.Fail("There was nothing to encrypt", (string)null));
}
if (String.IsNullOrWhiteSpace(key))
{
return(CommandResultFactory.Fail("The given encryption key was null or empty", cipherText));
}
try
{
var result = CreateCustomCipher(key, blockSize, keySize)
.Then(cipher =>
{
var splitCipher = cipherText.Split('_');
if (splitCipher.Length != 2)
{
return(CommandResultFactory.Fail("The given cipher text was not in the correct encrypted format for decryption",
(string)null));
}
var initVector = splitCipher[0];
var encryptedString = splitCipher[1];
if (initVector.Length % 2 != 0 || encryptedString.Length % 2 != 0)
{
return(CommandResultFactory.Fail("The given cipher text was not in the correct encrypted format for decryption",
(string)null));
}
cipher.IV = initVector.ToHexBytes();
var cryptoTransform = cipher.CreateDecryptor();
var cipherBytes = encryptedString.ToHexBytes();
if (cipherBytes == null)
{
return(CommandResultFactory.Fail(
"The encrypted string could not be converted into a Hexadecimal Byte Array and therefore could not be decrypted.",
(string)null));
}
var resultTextBytes = cryptoTransform.TransformFinalBlock(cipherBytes, 0, cipherBytes.Length);
var resultText = resultTextBytes.ToUTF8String();
return(resultText == null
? CommandResultFactory.Fail("Could not convert the decrypted bytes into a string.", (string)null)
: CommandResultFactory.Ok <string>(resultText));
});
return(result);
}
catch (Exception e)
{
Trace.WriteLine(e);
return(CommandResultFactory.Fail($"An exception was thrown while attempting to decrypt the given text. It is as follows:\n\t{e.Message}", (string)null));
}
}
/// <summary>
/// Generates an AES key.
/// </summary>
/// <remarks>
/// The key size of the Aes encryption must be 128, 192 or 256 bits.
/// Please check https://blogs.msdn.microsoft.com/shawnfa/2006/10/09/the-differences-between-rijndael-and-aes/ for more informations.
/// </remarks>
/// <param name="keySize">AES Key size</param>
/// <returns></returns>
public static AesKeyInfo GenerateKey(AesKeySize keySize)
{
var crypto = new AesCryptoServiceProvider
{
KeySize = (int)keySize,
BlockSize = AesBlockSize
};
crypto.GenerateKey();
crypto.GenerateIV();
return(new AesKeyInfo(crypto.Key, crypto.IV));
}
public void EncryptDecryptByteArrayTest(AesKeySize keySize)
{
byte[] input = DataHelper.RandomBytes(20);
AesKeyInfo encryptionKeyInfo = AesProvider.GenerateKey(keySize);
var provider = new AesProvider(encryptionKeyInfo.Key);
byte[] encryptedData = provider.Encrypt(input, b => b, StandardConverters.StreamToBytes);
Assert.NotNull(encryptedData);
byte[] decryptedData = provider.Decrypt(encryptedData, b => b, StandardConverters.StreamToBytes);
Assert.NotNull(decryptedData);
Assert.Equal(input, decryptedData);
}
public void EncryptDecryptStringTest(AesKeySize keySize)
{
string input = DataHelper.RandomString(20);
AesKeyInfo encryptionKeyInfo = AesProvider.GenerateKey(keySize);
var provider = new AesProvider(encryptionKeyInfo.Key);
string encryptedData = provider.Encrypt(input, Encoding.UTF8.GetBytes, StandardConverters.StreamToBase64String);
Assert.NotNull(encryptedData);
string decryptedData = provider.Decrypt(encryptedData, Convert.FromBase64String, StandardConverters.StreamToString);
Assert.NotNull(decryptedData);
Assert.Equal(input, decryptedData);
}
public void CompareTwoAesKeysInstancesTest(AesKeySize keySize)
{
AesKeyInfo encryptionKeyInfo1 = AesProvider.GenerateKey(keySize);
AesKeyInfo encryptionKeyInfo2 = AesProvider.GenerateKey(keySize);
AesKeyInfo encryptionKeyInfoCopy = encryptionKeyInfo1;
Assert.NotNull(encryptionKeyInfo1.Key);
Assert.NotNull(encryptionKeyInfo1.IV);
Assert.NotNull(encryptionKeyInfo2.Key);
Assert.NotNull(encryptionKeyInfo2.IV);
Assert.True(encryptionKeyInfo1 == encryptionKeyInfoCopy);
Assert.True(encryptionKeyInfo1.Equals(encryptionKeyInfoCopy));
Assert.True(encryptionKeyInfo1 != encryptionKeyInfo2);
Assert.True(encryptionKeyInfo1.GetHashCode() != encryptionKeyInfo2.GetHashCode());
Assert.False(encryptionKeyInfo1.Equals(0));
}
public void EncryptDecryptStringTest(AesKeySize keySize)
{
string input = StringHelper.RandomString(20);
AesKeyInfo encryptionKeyInfo = AesProvider.GenerateKey(keySize);
var provider = new AesProvider(encryptionKeyInfo.Key);
string encryptedData = provider.Encrypt(input);
Assert.NotNull(encryptedData);
string decryptedData = provider.Decrypt(encryptedData);
Assert.NotNull(decryptedData);
Assert.Equal(input, decryptedData);
}
public static ICryptoTransform CreateEncryptor(byte[] key, byte[] IV, AesKeySize keySize = AesKeySize.Aes128)
{
if (IV.Length != 12)
{
throw new ArgumentException($"IV length not equal {12}");
}
byte[] newIV = new byte[16];
Array.Copy(IV, 0, newIV, 0, IV.Length);
Aes aes = new Aes(key.Copy(), newIV, keySize);
aes.PaddingMode = PaddingMode.None;
aes.EncryptMode = EncryptModeEnum.CTR;
aes.InitializeRoundKey();
return(new AesCTREncryptor(aes));
}
/// <summary>
/// Sets up all the parameters and properties for the AES cipher used in the encryption.
/// </summary>
/// <param name="cipher">
/// The already created AES cipher. This should be created within a using statement and then handed
/// off to this method.
/// </param>
/// <param name="key">The (HEXADECIMAL) key used for encryption inside the cipher</param>
/// <param name="keySize">Key size used for setting up the cipher</param>
public CommandResult <Aes> SetupCipher(Aes cipher, string key, AesKeySize keySize)
{
if (cipher == null)
{
return(CommandResultFactory.Fail("The given AES cipher object was null", (Aes)null));
}
if (String.IsNullOrWhiteSpace(key))
{
return(CommandResultFactory.Fail("The cipher creation key for the encryption was null or empty", (Aes)null));
}
byte[] keyBytes;
try
{
keyBytes = key.ToHexBytes();
if (keyBytes == null || keyBytes.Length != (int)keySize / 8)
{
return(CommandResultFactory.Fail($"The cipher creation key for the encryption did not match the specified key size of {keySize}",
(Aes)null));
}
}
catch (FormatException)
{
return(CommandResultFactory.Fail("The key was malformed and therefore threw a Format Exception when converting to a byte array.", (Aes)null));
}
catch (Exception e)
{
return(CommandResultFactory.Fail($"There was an exception thrown while trying to create the cipher. It is as follows:\n\t{e.Message}", (Aes)null));
}
cipher.KeySize = (int)keySize;
cipher.BlockSize = 128; // This is the default block size for AES encryption and apparently should not be changed according to what I'm reading
cipher.Padding = PaddingMode.PKCS7;
cipher.Mode = CipherMode.CBC;
cipher.Key = keyBytes;
cipher.GenerateIV();
return(CommandResultFactory.Ok(cipher));
}
private static void ExecuteAesEncryptionTest <TContext>(AesKeySize aesKeyType) where TContext : DatabaseContext
{
AesKeyInfo encryptionKeyInfo = AesProvider.GenerateKey(aesKeyType);
var provider = new AesProvider(encryptionKeyInfo.Key, CipherMode.CBC, PaddingMode.Zeros);
var author = new AuthorEntity("John", "Doe", 42)
{
Password = DataHelper.RandomSecureString(10),
Books = new List <BookEntity>
{
new("Lorem Ipsum", 300),
new("Dolor sit amet", 390)
}
};
using var contextFactory = new DatabaseContextFactory();
// Save data to an encrypted database context
using (var dbContext = contextFactory.CreateContext <TContext>(provider))
{
dbContext.Authors.Add(author);
dbContext.SaveChanges();
}
// Read decrypted data and compare with original data
using (var dbContext = contextFactory.CreateContext <TContext>(provider))
{
var authorFromDb = dbContext.Authors.Include(x => x.Books).FirstOrDefault();
Assert.NotNull(authorFromDb);
Assert.Equal(author.FirstName, authorFromDb.FirstName);
Assert.Equal(author.LastName, authorFromDb.LastName);
Assert.NotNull(authorFromDb.Books);
Assert.NotEmpty(authorFromDb.Books);
Assert.Equal(2, authorFromDb.Books.Count);
Assert.Equal(author.Books.First().Name, authorFromDb.Books.First().Name);
Assert.Equal(author.Books.Last().Name, authorFromDb.Books.Last().Name);
}
}
/// <summary>
/// Encrypts the given text using the given key and key size for cipher creation.
/// </summary>
/// <param name="textForEncryption">Text to encrypt</param>
/// <param name="key">The (HEXADECIMAL) encryption key to use for creating the cipher</param>
/// <param name="keySize">Size of the key used for creating the cipher</param>
public CommandResult <string> Encrypt(string textForEncryption, string key, AesKeySize keySize)
{
if (String.IsNullOrWhiteSpace(textForEncryption))
{
return(CommandResultFactory.Fail("There was nothing to encrypt", (string)null));
}
if (String.IsNullOrWhiteSpace(key))
{
return(CommandResultFactory.Fail("The given encryption key was null or empty", textForEncryption));
}
try
{
CommandResult <string> result;
using (var aesCipher = Aes.Create())
{
result = SetupCipher(aesCipher, key, keySize)
.Then(aes =>
{
var initVector = aes.IV.ToHexString();
var textForEncryptBytes = textForEncryption.ToUtf8Bytes();
var cryptoTransform = aes.CreateEncryptor();
var cipherTextBytes = cryptoTransform.TransformFinalBlock(textForEncryptBytes, 0, textForEncryption.Length);
var cipherText = cipherTextBytes.ToHexString();
var textResult = $"{initVector}_{cipherText}";
return(CommandResultFactory.Ok <string>(textResult));
});
}
return(result);
}
catch (Exception e)
{
var message = $"An exception was thrown while trying to encrypt the text. It is as follows:\n{e.Message}";
return(CommandResultFactory.Fail(message, (string)null));
}
}
public ICryptoTransform CreateEcbDecryptor(string key, AesKeySize keySize = AesKeySize.Aes128, PaddingMode paddingMode = PaddingMode.PKCS7) => CreateEcbDecryptor(key.GetKey(keySize), keySize, paddingMode);
private ICryptoTransform CreateEncryptor(byte[] key, byte[] IV, EncryptModeEnum encryptMode, AesKeySize keySize = AesKeySize.Aes128, PaddingMode paddingMode = PaddingMode.PKCS7)
{
if (EncryptModeEnum.CBC.Equals(encryptMode))
{
return(AesCBCEncryptor.CreateEncryptor(key, IV, keySize, paddingMode));
}
if (EncryptModeEnum.CTR.Equals(encryptMode))
{
return(AesCTREncryptor.CreateEncryptor(key, IV, keySize));
}
throw new Exception($"Encryption Mode {encryptMode} not valid");
}
public ICryptoTransform CreateCtrEncryptor(byte[] key, byte[] IV, AesKeySize keySize = AesKeySize.Aes128, PaddingMode paddingMode = PaddingMode.PKCS7) => CreateEncryptor(key, IV, EncryptModeEnum.CTR, keySize, paddingMode);
public ICryptoTransform CreateCtrEncryptor(string key, byte[] IV, AesKeySize keySize = AesKeySize.Aes128, PaddingMode paddingMode = PaddingMode.PKCS7) => CreateCtrEncryptor(key.GetKey(keySize), IV, keySize, paddingMode);
/// <summary>
/// 生成AES KEY（Generate AES KEY）
/// </summary>
/// <param name="keySize">AES KEY 长度（128-bit、192-bit、256-bit）</param>
/// <returns></returns>
public static string AESGenerateKey(AesKeySize keySize)
{
return(AESGenerateKey(keySize.ToInt()));
}
private IAuthenticatedCryptoTransform CreateDecryptor(byte[] key, byte[] IV, byte[] additionalData, string tag, AesKeySize keySize = AesKeySize.Aes128)
{
Aes aes = CreateAesGcm(key, IV, keySize);
return(new AesGCMEncryptor(aes, additionalData, tag));
}
public IAuthenticatedCryptoTransform CreateGcmDecryptor(byte[] key, byte[] IV, byte[] additionalData, string tag, AesKeySize keySize = AesKeySize.Aes128) => CreateDecryptor(key, IV, additionalData, tag, keySize);
public IAuthenticatedCryptoTransform CreateGcmEncryptor(byte[] key, byte[] IV, byte[] additionalData, AesKeySize keySize = AesKeySize.Aes128) => CreateEncryptor(key, IV, additionalData, keySize);
public ICryptoTransform CreateEcbDecryptor(byte[] key, AesKeySize keySize = AesKeySize.Aes128, PaddingMode paddingMode = PaddingMode.PKCS7) => CreateDecryptor(key, keySize, paddingMode);
public AesManagerContext(byte[] byteKey, AesKeySize keySize = AesKeySize.Aes128)
{
aes = new Aes(byteKey, keySize);
}
public static byte[] GetKey(this string key, AesKeySize keySize) => key.GetKey((int)keySize / 8);
