/// <summary>
/// 暗号化された文字列を復号化する
/// </summary>
public static string DecryptString(string str, string password)
{
var aes = new System.Security.Cryptography.AesCryptoServiceProvider();
var passwordBytes = System.Text.Encoding.UTF8.GetBytes(password);
aes.Key = ResizeBytesArray(passwordBytes, aes.Key.Length);
aes.IV = ResizeBytesArray(passwordBytes, aes.IV.Length);
var data = System.Convert.FromBase64String(str);
var stream = new System.IO.MemoryStream(data);
var decryptor = aes.CreateDecryptor();
var cryptStreem = new System.Security.Cryptography.CryptoStream(
stream,
decryptor,
System.Security.Cryptography.CryptoStreamMode.Read
);
var reader = new System.IO.StreamReader(
cryptStreem,
System.Text.Encoding.UTF8
);
try {
var result = reader.ReadToEnd();
return(result);
} finally {
reader.Close();
cryptStreem.Close();
stream.Close();
}
}
public string Decrypt(byte[] inputDataBytes, byte[] keyBytes, byte[] ivBytes)
{
if (inputDataBytes == null || inputDataBytes.Length <= 0)
{
throw new ArgumentNullException("plainText");
}
if (keyBytes == null || keyBytes.Length <= 0)
{
throw new ArgumentNullException("Key");
}
if (ivBytes == null || ivBytes.Length <= 0)
{
throw new ArgumentNullException("IV");
}
System.IO.MemoryStream memoryStream;
using (System.Security.Cryptography.AesCryptoServiceProvider csp = new System.Security.Cryptography.AesCryptoServiceProvider())
{
csp.Key = keyBytes;
csp.IV = ivBytes;
//csp.CreateEncryptor
// Create an encryptor to perform the stream transform.
System.Security.Cryptography.ICryptoTransform cryptoTransformer = csp.CreateDecryptor(csp.Key, csp.IV);
// Create the streams used for encryption.
using (memoryStream = new System.IO.MemoryStream(inputDataBytes))
using (System.Security.Cryptography.CryptoStream cryptoStream = new System.Security.Cryptography.CryptoStream(memoryStream, cryptoTransformer, System.Security.Cryptography.CryptoStreamMode.Read))
using (System.IO.StreamReader sr = new System.IO.StreamReader(cryptoStream))
{
return(sr.ReadToEnd());
}
}
}
public static string Decrypt_Aes(this object value, string aesKey, string aesIV)
{
byte[] cipherText = GetBytes(value as string);
byte[] Key = GetBytes(aesKey);
byte[] IV = GetBytes(aesIV);
// Check arguments.
if (cipherText == null || cipherText.Length <= 0)
throw new ArgumentNullException("cipherText");
if (Key == null || Key.Length <= 0)
throw new ArgumentNullException("Key");
if (IV == null || IV.Length <= 0)
throw new ArgumentNullException("IV");
// Declare the string used to hold
// the decrypted text.
string plaintext = null;
// Create an AesCryptoServiceProvider object
// with the specified key and IV.
using (System.Security.Cryptography.AesCryptoServiceProvider aesAlg = new System.Security.Cryptography.AesCryptoServiceProvider())
{
aesAlg.Key = Key;
aesAlg.IV = IV;
// Create a decrytor to perform the stream transform.
System.Security.Cryptography.ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for decryption.
using (MemoryStream msDecrypt = new MemoryStream(cipherText))
{
using (System.Security.Cryptography.CryptoStream csDecrypt = new System.Security.Cryptography.CryptoStream(msDecrypt, decryptor, System.Security.Cryptography.CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
{
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
}
}
}
}
return plaintext;
}
//-------------------------------------------------
public static string AesDecrypt(string password, string base64)
{
// Turn input string into a byte array.
var input = System.Convert.FromBase64String(base64);
// Create an instance of the Rijndael class.
var cipher = new System.Security.Cryptography.AesCryptoServiceProvider();
// Calculate salt to make it harder to guess key by using a dictionary attack.
var passwordBytes = System.Text.Encoding.UTF8.GetBytes(password);
var hmac = new System.Security.Cryptography.HMACSHA1(passwordBytes);
var salt = hmac.ComputeHash(passwordBytes);
// Generate Secret Key from the password and salt.
// Note: Set number of iterations to 10 in order for JavaScript example to work faster.
var secretKey = new System.Security.Cryptography.Rfc2898DeriveBytes(passwordBytes, salt, 10);
// Create a encryptor from the existing SecretKey bytes by using
// 32 bytes (256 bits) for the secret key and
// 16 bytes (128 bits) for the initialization vector (IV).
var key = secretKey.GetBytes(32);
var iv = secretKey.GetBytes(16);
// Get cryptor as System.Security.Cryptography.ICryptoTransform class.
var cryptor = cipher.CreateDecryptor(key, iv);
// Create new Input.
var inputBuffer = new System.Byte[input.Length];
// Copy data bytes to input buffer.
System.Buffer.BlockCopy(input, 0, inputBuffer, 0, inputBuffer.Length);
// Create a MemoryStream to hold the output bytes.
var stream = new System.IO.MemoryStream();
// Create a CryptoStream through which we are going to be processing our data.
var mode = System.Security.Cryptography.CryptoStreamMode.Write;
var cryptoStream = new System.Security.Cryptography.CryptoStream(stream, cryptor, mode);
// Start the decrypting process.
cryptoStream.Write(inputBuffer, 0, inputBuffer.Length);
// Finish decrypting.
cryptoStream.FlushFinalBlock();
// Convert data from a memoryStream into a byte array.
var outputBuffer = stream.ToArray();
// Close both streams.
stream.Close();
//cryptoStream.Close();
// Convert encrypted data into a base64-encoded string.
var s = System.Text.Encoding.UTF8.GetString(outputBuffer);
return(s);
}
public static byte[] AESDecrypt(byte[] input)
{
using (var aes = new System.Security.Cryptography.AesCryptoServiceProvider())
{
aes.Key = aeskey;
aes.IV = aesvector;
using (var ms = new System.IO.MemoryStream())
{
var cs = new System.Security.Cryptography.CryptoStream(ms, aes.CreateDecryptor(), System.Security.Cryptography.CryptoStreamMode.Write);
if (cs == null)
{
return(null);
}
cs.Write(input, 0, input.Length);
cs.FlushFinalBlock();
return(ms.ToArray());
}
}
}
public static string aesDecryptBase64(string SourceStr, ulong Key)
{
string decrypt = "";
try
{
var aes = new System.Security.Cryptography.AesCryptoServiceProvider();
var md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
var sha256 = new System.Security.Cryptography.SHA256CryptoServiceProvider();
byte[] key = sha256.ComputeHash(BitConverter.GetBytes(Key));
byte[] iv = md5.ComputeHash(BitConverter.GetBytes(Key));
aes.Key = key;
aes.IV = iv;
byte[] dataByteArray = Convert.FromBase64String(SourceStr);
using (var ms = new System.IO.MemoryStream())
{
using (var cs = new System.Security.Cryptography.CryptoStream(ms, aes.CreateDecryptor(), System.Security.Cryptography.CryptoStreamMode.Write))
{
cs.Write(dataByteArray, 0, dataByteArray.Length);
cs.FlushFinalBlock();
decrypt = Encoding.UTF8.GetString(ms.ToArray());
}
}
}
catch (Exception e)
{
}
return(decrypt);
}
