public string Encrypt(string data)
{
SecureRandom random = new SecureRandom();
// Generate 256-bits AES key
byte[] aesKey = new byte[32];
random.NextBytes(aesKey);
// Generate Initialization Vector
byte[] IV = new byte[12];
random.NextBytes(IV);
// Apply RSA/None/PKCS1Padding encryption to the AES key
byte[] encyptedAESKey = rsaCipher.DoFinal(aesKey);
// Apply AES/CCM/NoPadding encryption to the data
byte[] cipherText = System.Text.Encoding.UTF8.GetBytes(data);
var ccmParameters = new CcmParameters(new KeyParameter(aesKey), 64, IV, new byte[] { });
aesCipher = new CcmBlockCipher(new AesFastEngine());
aesCipher.Init(true, ccmParameters);
var encrypted = new byte[aesCipher.GetOutputSize(cipherText.Length)];
var res = aesCipher.ProcessBytes(cipherText, 0, cipherText.Length, encrypted, 0);
aesCipher.DoFinal(encrypted, res);
// Merge 'IV' and 'encrypted' to 'result'
byte[] result = new byte[IV.Length + encrypted.Length];
System.Buffer.BlockCopy(IV, 0, result, 0, IV.Length);
System.Buffer.BlockCopy(encrypted, 0, result, IV.Length, encrypted.Length);
// Return encrypted data
return Prefix + Version + Separator + System.Convert.ToBase64String(encyptedAESKey) + Separator + System.Convert.ToBase64String(result);
}
public static Stream Encrypt(Stream stream, out string seed_encoded, out string ident_encoded, string fileName)
{
RNGCryptoServiceProvider rngCsp = new RNGCryptoServiceProvider();
byte[] seed = new byte[16];
rngCsp.GetBytes(seed);
seed_encoded = UrlBase64Encode(seed);
SHA512CryptoServiceProvider sha512csp = new SHA512CryptoServiceProvider();
byte[] seed_result = sha512csp.ComputeHash(seed);
byte[] key = new byte[32];
Buffer.BlockCopy(seed_result, 0, key, 0, 32);
byte[] iv = new byte[16];
Buffer.BlockCopy(seed_result, 32, iv, 0, 16);
byte[] ident = new byte[16];
Buffer.BlockCopy(seed_result, 48, ident, 0, 16);
ident_encoded = UrlBase64Encode(ident);
var fi = new FileInfo(fileName);
Dictionary<string, string> args = new Dictionary<string, string>();
// text files aren't detected well by the "ClouDeveloper" mime type library, use ShareX's builtin list first.
if (Helpers.IsTextFile(fileName))
{
args["mime"] = "text/plain";
}
else
{
var mimeOpts = ClouDeveloper.Mime.MediaTypeNames.GetMediaTypeNames(fi.Extension).ToList();
args["mime"] = mimeOpts.Count > 0 ? mimeOpts[0] : "image/png";
}
args["name"] = fileName;
byte[] d = Encoding.BigEndianUnicode.GetBytes(JsonConvert.SerializeObject(args));
byte[] rawdata = d.Concat(new byte[] { 0, 0 }).Concat(stream.GetBytes()).ToArray();
int l = FindIVLen(rawdata.Length);
byte[] civ = new byte[l];
Array.Copy(iv, civ, l);
KeyParameter key_param = new KeyParameter(key);
var ccmparams = new CcmParameters(key_param, MacSize, civ, new byte[0]);
var ccmMode = new CcmBlockCipher(new AesFastEngine());
ccmMode.Init(true, ccmparams);
var encBytes = new byte[ccmMode.GetOutputSize(rawdata.Length)];
var res = ccmMode.ProcessBytes(rawdata, 0, rawdata.Length, encBytes, 0);
ccmMode.DoFinal(encBytes, res);
return new MemoryStream(encBytes);
}
private static MemoryStream Encrypt(Stream source, string fileName, out string seed_encoded, out string ident)
{
// Randomly generate a new seed for upload
byte[] seed = new byte[16];
using (RNGCryptoServiceProvider rngCsp = new RNGCryptoServiceProvider())
{
rngCsp.GetBytes(seed);
}
seed_encoded = UrlBase64Encode(seed);
// Derive the parameters (key, IV, ident) from the seed
byte[] key, iv;
DeriveParams(seed, out key, out iv, out ident);
// Create a new String->String map for JSON blob, and define filename and metadata
Dictionary<string, string> metadataMap = new Dictionary<string, string>();
metadataMap["mime"] = Helpers.IsTextFile(fileName) ? "text/plain" : Helpers.GetMimeType(fileName);
metadataMap["name"] = fileName;
// Encode the metadata with UTF-16 and a double-null-byte terminator, and append data
// Unfortunately, the CCM cipher mode can't stream the encryption, and so we have to GetBytes() on the source.
// We do limit the source to 50MB however
byte[] data = Encoding.BigEndianUnicode.GetBytes(JsonConvert.SerializeObject(metadataMap)).Concat(new byte[] { 0, 0 }).Concat(source.GetBytes()).ToArray();
// Calculate the length of the CCM IV and copy it over
long ccmIVLen = FindIVLen(data.Length);
byte[] ccmIV = new byte[ccmIVLen];
Array.Copy(iv, ccmIV, ccmIVLen);
// Set up the encryption parameters
KeyParameter keyParam = new KeyParameter(key);
CcmParameters ccmParams = new CcmParameters(keyParam, MacSize, ccmIV, new byte[0]);
CcmBlockCipher ccmMode = new CcmBlockCipher(new AesFastEngine());
ccmMode.Init(true, ccmParams);
// Perform the encryption
byte[] encBytes = new byte[ccmMode.GetOutputSize(data.Length)];
int res = ccmMode.ProcessBytes(data, 0, data.Length, encBytes, 0);
ccmMode.DoFinal(encBytes, res);
return new MemoryStream(encBytes);
}
public void Init(bool forEncryption, ICipherParameters parameters)
{
if (!(parameters is CcmParameters))
{
throw new ArgumentException("parameters need to be CCMParameters");
}
this.forEncryption = forEncryption;
this.parameters = (CcmParameters)parameters;
}
/// <summary>
/// Encrypt the message using the passed key and pre-calculated nonce.
/// </summary>
/// <param name="messageBytes"></param>
/// <param name="encryptionKeyHex"></param>
/// <param name="nonceBytes"></param>
/// <returns></returns>
private static byte[] EncryptMessage(byte[] messageBytes, string encryptionKeyHex, byte[] nonceBytes)
{
if (string.IsNullOrEmpty(encryptionKeyHex))
return messageBytes;
var key = StringToByteArray(encryptionKeyHex);
var cipher = new CcmBlockCipher(new AesFastEngine());
var parameters = new CcmParameters(new KeyParameter(key), 64, nonceBytes, new byte[] {});
//var parameters = new CcmParameters(new KeyParameter(key), 64, nonceBytes, System.Text.Encoding.UTF8.GetBytes("testing much data"));
cipher.Init(true, parameters);
var encryptedBytes = new byte[cipher.GetOutputSize(messageBytes.Length)];
var res = cipher.ProcessBytes(messageBytes, 0, messageBytes.Length, encryptedBytes, 0);
cipher.DoFinal(encryptedBytes, res);
return encryptedBytes;
}
private static byte[] DecryptMessage(byte[] encryptedBytes, string encryptionKeyHex)
{
if (string.IsNullOrEmpty(encryptionKeyHex))
return encryptedBytes;
var headerBytes = encryptedBytes.Take(1).ToArray(); // 0xFF
var nonceBytes = encryptedBytes.Skip(1).Take(7).ToArray();
encryptedBytes = encryptedBytes.Skip(8).ToArray();
var key = StringToByteArray(encryptionKeyHex);
var cipher = new CcmBlockCipher(new AesFastEngine());
var parameters = new CcmParameters(new KeyParameter(key), 64, nonceBytes, new byte[] { });
cipher.Init(false, parameters);
var plainBytes = new byte[cipher.GetOutputSize(encryptedBytes.Length)];
var res = cipher.ProcessBytes(encryptedBytes, 0, encryptedBytes.Length, plainBytes, 0);
cipher.DoFinal(plainBytes, res);
return plainBytes;
}
public static string Decrypt(string password, string data)
{
SJCLBlob ctdata = JsonConvert.DeserializeObject<SJCLBlob>(data);
if (ctdata.Cipher != "aes" || ctdata.Mode != "ccm")
throw new InvalidOperationException("Unsupported cipher or mode.");
byte[] cipherText = DecodeBase64(ctdata.CipherText);
var derivedMacParameters = DeriveKey(password, ctdata);
var l = FindIVLen(cipherText.Length);
byte[] iv = new byte[l];
Array.Copy((Array) DecodeBase64(ctdata.IV), (Array) iv, (int) l);
var ccmparams = new CcmParameters(derivedMacParameters, ctdata.TagSize, iv, DecodeBase64(ctdata.AuthData));
var ccmMode = new CcmBlockCipher(new AesFastEngine());
ccmMode.Init(false, ccmparams);
var plainBytes = new byte[ccmMode.GetOutputSize(cipherText.Length)];
var res = ccmMode.ProcessBytes(cipherText, 0, cipherText.Length, plainBytes, 0);
ccmMode.DoFinal(plainBytes, res);
return Encoding.UTF8.GetString(plainBytes);
}
public static string Encrypt(string password, string data)
{
RNGCryptoServiceProvider rngCsp = new RNGCryptoServiceProvider();
byte[] salt = new byte[8];
rngCsp.GetBytes(salt);
byte[] iv = new byte[16];
rngCsp.GetBytes(iv);
SJCLBlob ctdata = new SJCLBlob()
{
Mode = "ccm",
Cipher = "aes",
AuthData = "",
Iterations = 2000,
KeySize = 256,
TagSize = 64,
Salt = Convert.ToBase64String(salt),
IV = Convert.ToBase64String(iv),
V = 1
};
var key = DeriveKey(password, ctdata);
byte[] rawdata = Encoding.UTF8.GetBytes(data);
var l = FindIVLen(rawdata.Length);
byte[] civ = new byte[l];
Array.Copy((Array) iv, (Array) civ, (int) l);
var ccmparams = new CcmParameters(key, ctdata.TagSize, civ, DecodeBase64(ctdata.AuthData));
var ccmMode = new CcmBlockCipher(new AesFastEngine());
ccmMode.Init(true, ccmparams);
var encBytes = new byte[ccmMode.GetOutputSize(rawdata.Length)];
var res = ccmMode.ProcessBytes(rawdata, 0, rawdata.Length, encBytes, 0);
ccmMode.DoFinal(encBytes, res);
ctdata.CipherText = Convert.ToBase64String(encBytes);
return JsonConvert.SerializeObject(ctdata);
}
