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public static GetBytes ( Byte bytes, |
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| bytes | Byte | |
| count | ||
| offset | ||
| Результат | Byte[] | |
private Byte[] Decrypt(Type symmetricAlgorithm, Byte[] symmetricKey, Byte[] cipherText)
{
Contract.Requires(symmetricAlgorithm != null);
Contract.Requires(symmetricKey != null && symmetricKey.Length > 0);
Contract.Requires(cipherText != null && cipherText.Length > 0);
var algorithm = (SymmetricAlgorithm)Activator.CreateInstance(symmetricAlgorithm);
var ivSize = algorithm.BlockSize / 8;
if (cipherText.Length < ivSize)
{
throw new ArgumentException("The cipherText specified is invalid and does not contain the initialization vector.");
}
algorithm.Key = symmetricKey;
algorithm.IV = CryptographyUtility.GetBytes(cipherText, ivSize);
var cipher = CryptographyUtility.GetBytes(cipherText, cipherText.Length - ivSize, ivSize);
using (var encryptedStream = new MemoryStream(cipher))
using (var plainTextStream = new MemoryStream())
using (var decryptionStream = new CryptoStream(encryptedStream, algorithm.CreateDecryptor(algorithm.Key, algorithm.IV), CryptoStreamMode.Read))
{
decryptionStream.CopyTo(plainTextStream);
return(plainTextStream.ToArray());
}
}
private async Task DecryptAsync(Type symmetricAlgorithm, Byte[] symmetricKey, Stream cipherText, Stream plainText)
{
Contract.Requires(symmetricAlgorithm != null);
Contract.Requires(symmetricKey != null && symmetricKey.Length > 0);
Contract.Requires(cipherText != null);
Contract.Requires(plainText != null);
var algorithm = (SymmetricAlgorithm)Activator.CreateInstance(symmetricAlgorithm);
var ivSize = algorithm.BlockSize / 8;
if (cipherText.Length < ivSize)
{
throw new ArgumentException("The cipherText specified is invalid and does not contain the initialization vector.");
}
cipherText.Position = 0;
plainText.Position = 0;
algorithm.Key = symmetricKey;
algorithm.IV = CryptographyUtility.GetBytes(cipherText, ivSize);
cipherText.Position = ivSize;
var decryptionStream = new CryptoStream(cipherText, algorithm.CreateDecryptor(algorithm.Key, algorithm.IV), CryptoStreamMode.Read);
await decryptionStream.CopyToAsync(plainText);
cipherText.Position = 0;
plainText.Position = 0;
}
private Boolean CompareHash(Type hashAlgorithmType, Byte[] plainText, Byte[] hashedBytes, Int32 saltLength = 16)
{
var hashAlgorithm = Activator.CreateInstance(hashAlgorithmType, true) as HashAlgorithm;
if (hashAlgorithm == null)
{
throw new InvalidOperationException(String.Format("Could not create instance of type {0}.", hashAlgorithmType));
}
var salt = CryptographyUtility.GetBytes(hashedBytes, saltLength);
var targetHash = CryptographyUtility.CombineBytes(salt, hashAlgorithm.ComputeHash(CryptographyUtility.CombineBytes(salt, plainText)));
return(CryptographyUtility.CompareBytes(hashedBytes, targetHash));
}