Encryption and decryption of XML file

Encryption and decryption of XML file - c#

I want to encrypt an XML file and decrypt the same in a different machine in c#. Please help......
I have already tried with RSA algorithm and RijndaelManaged key but not able to decrypt the file in different machine.

From the problem description, you're probably looking into symmetric encryption algorithm. This is something that should get you started:
public class Key {
public string Password { get; set; }
public byte[] Salt { get; set; }
public string Vector { get; set; }
public PaddingMode? Padding { get; set; }
}
public class AesCryptor {
private const int HASH_SIZE = 32;
private ICryptoTransform m_Decryptor;
private ICryptoTransform m_Encryptor;
private TimeSpan m_Validity;
// Methods
public AesCryptor(Key key, TimeSpan validity) {
if (key == null) {
throw new ArgumentNullException("key");
}
m_Validity = validity;
using (AesManaged aes = new AesManaged()) {
aes.Mode = CipherMode.CBC;
aes.Key = new Rfc2898DeriveBytes(key.Password, key.Salt).GetBytes(aes.KeySize / 8);
aes.IV = Encoding.ASCII.GetBytes(key.Vector);
if (key.Padding.HasValue) {
aes.Padding = key.Padding.Value;
}
m_Encryptor = aes.CreateEncryptor();
m_Decryptor = aes.CreateDecryptor();
}
}
private static bool CompareArray(byte[] first, byte[] second) {
if (first.Length != second.Length) {
return false;
}
for (int i = 0; i < first.Length; i++) {
if (first[i] != second[i]) {
return false;
}
}
return true;
}
public byte[] Decrypt(byte[] encryptedData) {
byte[] hash;
if (encryptedData == null) {
throw new ArgumentNullException("encryptedData");
}
byte[] buffer = m_Decryptor.TransformFinalBlock(encryptedData, 0, encryptedData.Length);
using (SHA256 sha = SHA256.Create()) {
hash = sha.ComputeHash(buffer, 0, buffer.Length - HASH_SIZE);
}
byte[] orginalHash = new byte[HASH_SIZE];
Buffer.BlockCopy(buffer, buffer.Length - HASH_SIZE, orginalHash, 0, HASH_SIZE);
if (!CompareArray(orginalHash, hash)) {
throw new Exception("Hash match failure.");
}
if (m_Validity != TimeSpan.Zero) {
DateTime timestamp = new DateTime(BitConverter.ToInt64(buffer, (buffer.Length - HASH_SIZE) - 8));
TimeSpan delta = (TimeSpan)(DateTime.Now - timestamp);
if (delta > m_Validity) {
throw new Exception("Timestamp too old.");
}
}
byte[] result = new byte[(buffer.Length - HASH_SIZE) - 8];
Buffer.BlockCopy(buffer, 0, result, 0, (buffer.Length - HASH_SIZE) - 8);
return result;
}
public byte[] Encrypt(byte[] data) {
byte[] hash;
if (data == null) {
throw new ArgumentNullException("data");
}
byte[] buffer = new byte[(data.Length + 8) + HASH_SIZE];
Buffer.BlockCopy(data, 0, buffer, 0, data.Length);
Buffer.BlockCopy(BitConverter.GetBytes(DateTime.Now.Ticks), 0, buffer, data.Length, 8);
using (SHA256 sha = SHA256.Create()) {
hash = sha.ComputeHash(buffer, 0, buffer.Length - HASH_SIZE);
}
Buffer.BlockCopy(hash, 0, buffer, buffer.Length - HASH_SIZE, HASH_SIZE);
return m_Encryptor.TransformFinalBlock(buffer, 0, buffer.Length);
}
}
Usage:
var myKey = new Key {
Password = "whatever,nevermind#$",
Vector = "Q^!#g1353hdhjs*-",
Salt = new byte[] { 0x33, 0x4d, 0x56, 0x4f, 1, 0x22, 15, 0x7f }
};
var cryptor = new AesCryptor(myKey, TimeSpan.Zero);
// this will encrypt c:\test.xml into byte array
byte[] encrypted = cryptor.Encrypt(File.ReadAllBytes(#"c:\test.xml"));
// this will persist encrypted byte array into file c:\test-encrypted.bin
File.WriteAllBytes(#"c:\test-encrypted.bin", encrypted);
// this will load & decrypt bytes from file c:\test-encrypted.bin
byte[] decrypted = cryptor.Decrypt(File.ReadAllBytes(#"c:\test-encrypted.bin"));
// this will write decrypted bytes into c:\test-decrypted.xml
File.WriteAllBytes(#"c:\test-decrypted.xml", decrypted);

Related

Decrypt RijndaelManaged in C++ (CNG)

The C# code below outputs 0123456789012345678901234567890123456789:
static void Main(string[] args)
{
byte[] salt = Encoding.ASCII.GetBytes("saltycrack");
Console.WriteLine(Decrypt("NpN45cs2+bVLtEgp6ZmBmmHLH89aFdHIbDjhstTK0Vb1VMr7jBsliKD9siQGGxGS", "pass", salt));
}
public static string Decrypt(string encryptedText, string encryptionPassword, byte[] salt)
{
var algorithm = GetAlgorithm(encryptionPassword, salt);
using (ICryptoTransform decryptor = algorithm.CreateDecryptor(algorithm.Key, algorithm.IV))
{
byte[] encryptedBytes = Convert.FromBase64String(encryptedText);
return Encoding.UTF8.GetString(InMemoryCrypt(encryptedBytes, decryptor));
}
}
private static byte[] InMemoryCrypt(byte[] data, ICryptoTransform transform)
{
MemoryStream memory = new MemoryStream();
using (Stream stream = new CryptoStream(memory, transform, CryptoStreamMode.Write))
{
stream.Write(data, 0, data.Length);
}
return memory.ToArray();
}
private static RijndaelManaged GetAlgorithm(string encryptionPassword, byte[] salt)
{
var key = new Rfc2898DeriveBytes(encryptionPassword, salt);
var algorithm = new RijndaelManaged();
algorithm.Key = key.GetBytes(algorithm.KeySize / 8);
algorithm.IV = key.GetBytes(algorithm.BlockSize / 8);
return algorithm;
}
I want to do the same decryption using Microsoft CNG in C++:
int main(int argc, char** argv)
{
auto salt = std::string("saltycrack");
auto pass = std::string("pass");
std::string cipher_text = base64_decode("NpN45cs2+bVLtEgp6ZmBmmHLH89aFdHIbDjhstTK0Vb1VMr7jBsliKD9siQGGxGS");
NTSTATUS bcryptResult = 0;
BCRYPT_ALG_HANDLE alg = 0;
assert(BCRYPT_SUCCESS(BCryptOpenAlgorithmProvider(&alg, BCRYPT_AES_ALGORITHM, 0, 0)));
BCRYPT_ALG_HANDLE prf = NULL;
assert(BCRYPT_SUCCESS(BCryptOpenAlgorithmProvider(&prf, BCRYPT_SHA1_ALGORITHM, nullptr, BCRYPT_ALG_HANDLE_HMAC_FLAG)));
auto key_len = 32;
ULONGLONG iter = 1000;
ULONG kbh_len = sizeof(BCRYPT_KEY_DATA_BLOB_HEADER) + key_len;
BCRYPT_KEY_DATA_BLOB_HEADER* kbh = (BCRYPT_KEY_DATA_BLOB_HEADER*)malloc(kbh_len);
assert(BCRYPT_SUCCESS(BCryptDeriveKeyPBKDF2(prf, (PUCHAR)pass.data(), pass.size(), (PUCHAR)salt.data(), salt.size(), iter, (uint8_t*)(kbh + 1), key_len, 0)));
kbh->dwMagic = BCRYPT_KEY_DATA_BLOB_MAGIC;
kbh->dwVersion = BCRYPT_KEY_DATA_BLOB_VERSION1;
kbh->cbKeyData = key_len;
DWORD key_obj_len;
ULONG got;
assert(BCRYPT_SUCCESS(BCryptGetProperty(alg, BCRYPT_OBJECT_LENGTH, (PBYTE)&key_obj_len, sizeof(DWORD), &got, 0)));
uint8_t* key_obj = new uint8_t[key_obj_len];
BCRYPT_KEY_HANDLE key = 0;
assert(BCRYPT_SUCCESS(BCryptImportKey(alg, NULL, BCRYPT_KEY_DATA_BLOB, &key, key_obj, key_obj_len, (PUCHAR)kbh, kbh_len, 0)));
{
std::wstring mode = BCRYPT_CHAIN_MODE_CBC;
BYTE* ptr = reinterpret_cast<BYTE*>(const_cast<wchar_t*>(mode.data()));
ULONG size = static_cast<ULONG>(sizeof(wchar_t) * (mode.size() + 1));
assert(BCRYPT_SUCCESS(BCryptSetProperty(alg, BCRYPT_CHAINING_MODE, ptr, size, 0)));
}
DWORD bytes_done = 0;
DWORD block_len = 0;
assert(BCRYPT_SUCCESS(BCryptGetProperty(alg, BCRYPT_BLOCK_LENGTH, (BYTE*)&block_len, sizeof(block_len), &bytes_done, 0)));
auto iv = std::vector<uint8_t>(block_len);
ULONG bufferlen = 0;
assert(BCRYPT_SUCCESS(BCryptDecrypt(key, (PUCHAR)cipher_text.data(), cipher_text.size(), 0, (PUCHAR)iv.data(), iv.size(), 0, 0, &bufferlen, BCRYPT_BLOCK_PADDING)));
auto plaintext = std::string(bufferlen, '\0');
assert(BCRYPT_SUCCESS(BCryptDecrypt(key, (PUCHAR)cipher_text.data(), cipher_text.size(), 0, (PUCHAR)iv.data(), iv.size(), (PUCHAR)plaintext.data(), plaintext.size(), &bufferlen, BCRYPT_BLOCK_PADDING)));
std::cout << plaintext << "\n";
return 0;
}
The C++ program outputs #♂b⌡Cεk╘┴╟AÑ#├0⌠678901234567890123456789.
It looks like decryption partially succeeded which doesn't make sense.
Do I need to decode the decrypted data or is there data corruption somewhere?

RSA and PublicKey interop with dotnet

Hi I am using code from this link, Can you let me know why signature is verify is not working?
Java signer is using BouncyCastleProvider with SHA1withRSA, here is dotnet verify code....
using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.OpenSsl;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Utilities.Encoders;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
string pubkey = #"MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAMf54mcK3EYJn9tT9BhRoTX+8AkqojIyeSfog9ncYEye0VXyBULGg2lAQsDRt8lZsvPioORZW7eB6IKawshoWUsCAwEAAQ==";
String signature = "770bb2610bf6b2602ce2b3ad8489054f4ed59c9b0c9299327f76ecbc60a8bb9a725cfae901fc189d4bafcf73a2f4aed8dffe9842f7b6196ddfcd040c7271c7ca";
String signData = "C2:AE:D6:2B:DF:A4";
byte[] expectedSig = System.Convert.FromBase64String(signature);
byte[] baKey = System.Convert.FromBase64String(pubkey);
byte[] data = Encoding.UTF8.GetBytes(signData);
//Console.WriteLine(p.VerifyData(data, new SHA1CryptoServiceProvider(), expectedSig));
/* Init alg */
ISigner signer = SignerUtilities.GetSigner("SHA1withRSA");
/* Populate key */
signer.Init(false, DecodeX509PublicKey2(baKey));
/* Calculate the signature and see if it matches */
signer.BlockUpdate(data, 0, data.Length);
Console.WriteLine(signer.VerifySignature(expectedSig));
Console.In.ReadLine();
}
public static RsaKeyParameters DecodeX509PublicKey2(byte[] x509key)
{
byte[] SeqOID = { 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x01, 0x01 };
MemoryStream ms = new MemoryStream(x509key);
BinaryReader reader = new BinaryReader(ms);
if (reader.ReadByte() == 0x30)
ReadASNLength(reader); //skip the size
else
return null;
int identifierSize = 0; //total length of Object Identifier section
if (reader.ReadByte() == 0x30)
identifierSize = ReadASNLength(reader);
else
return null;
if (reader.ReadByte() == 0x06) //is the next element an object identifier?
{
int oidLength = ReadASNLength(reader);
byte[] oidBytes = new byte[oidLength];
reader.Read(oidBytes, 0, oidBytes.Length);
if (oidBytes.SequenceEqual(SeqOID) == false) //is the object identifier rsaEncryption PKCS#1?
return null;
int remainingBytes = identifierSize - 2 - oidBytes.Length;
reader.ReadBytes(remainingBytes);
}
if (reader.ReadByte() == 0x03) //is the next element a bit string?
{
ReadASNLength(reader); //skip the size
reader.ReadByte(); //skip unused bits indicator
if (reader.ReadByte() == 0x30)
{
ReadASNLength(reader); //skip the size
if (reader.ReadByte() == 0x02) //is it an integer?
{
int modulusSize = ReadASNLength(reader);
byte[] modulus = new byte[modulusSize];
reader.Read(modulus, 0, modulus.Length);
if (modulus[0] == 0x00) //strip off the first byte if it's 0
{
byte[] tempModulus = new byte[modulus.Length - 1];
Array.Copy(modulus, 1, tempModulus, 0, modulus.Length - 1);
modulus = tempModulus;
}
Array.Reverse(modulus); //convert to big-endian
if (reader.ReadByte() == 0x02) //is it an integer?
{
int exponentSize = ReadASNLength(reader);
byte[] exponent = new byte[exponentSize];
reader.Read(exponent, 0, exponent.Length);
Array.Reverse(exponent); //convert to big-endian
//RSAParameters RSAKeyInfo = new RSAParameters();
//RSAKeyInfo.Modulus = modulus;
//RSAKeyInfo.Exponent = exponent;
return MakeKey(BitConverter.ToString(modulus).Replace("-", string.Empty), BitConverter.ToString(exponent).Replace("-", string.Empty), false);
}
}
}
}
return null;
}
public static RsaKeyParameters MakeKey(String modulusHexString, String exponentHexString, bool isPrivateKey)
{
var modulus = new Org.BouncyCastle.Math.BigInteger(modulusHexString, 16);
var exponent = new Org.BouncyCastle.Math.BigInteger(exponentHexString, 16);
return new RsaKeyParameters(isPrivateKey, modulus, exponent);
}
public static RSACryptoServiceProvider DecodeX509PublicKey(byte[] x509key)
{
byte[] SeqOID = { 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x01, 0x01 };
MemoryStream ms = new MemoryStream(x509key);
BinaryReader reader = new BinaryReader(ms);
if (reader.ReadByte() == 0x30)
ReadASNLength(reader); //skip the size
else
return null;
int identifierSize = 0; //total length of Object Identifier section
if (reader.ReadByte() == 0x30)
identifierSize = ReadASNLength(reader);
else
return null;
if (reader.ReadByte() == 0x06) //is the next element an object identifier?
{
int oidLength = ReadASNLength(reader);
byte[] oidBytes = new byte[oidLength];
reader.Read(oidBytes, 0, oidBytes.Length);
if (oidBytes.SequenceEqual(SeqOID) == false) //is the object identifier rsaEncryption PKCS#1?
return null;
int remainingBytes = identifierSize - 2 - oidBytes.Length;
reader.ReadBytes(remainingBytes);
}
if (reader.ReadByte() == 0x03) //is the next element a bit string?
{
ReadASNLength(reader); //skip the size
reader.ReadByte(); //skip unused bits indicator
if (reader.ReadByte() == 0x30)
{
ReadASNLength(reader); //skip the size
if (reader.ReadByte() == 0x02) //is it an integer?
{
int modulusSize = ReadASNLength(reader);
byte[] modulus = new byte[modulusSize];
reader.Read(modulus, 0, modulus.Length);
if (modulus[0] == 0x00) //strip off the first byte if it's 0
{
byte[] tempModulus = new byte[modulus.Length - 1];
Array.Copy(modulus, 1, tempModulus, 0, modulus.Length - 1);
modulus = tempModulus;
}
Array.Reverse(modulus); //convert to big-endian
if (reader.ReadByte() == 0x02) //is it an integer?
{
int exponentSize = ReadASNLength(reader);
byte[] exponent = new byte[exponentSize];
reader.Read(exponent, 0, exponent.Length);
Array.Reverse(exponent); //convert to big-endian
RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
RSAParameters RSAKeyInfo = new RSAParameters();
RSAKeyInfo.Modulus = modulus;
RSAKeyInfo.Exponent = exponent;
RSA.ImportParameters(RSAKeyInfo);
return RSA;
}
}
}
}
return null;
}
public static int ReadASNLength(BinaryReader reader)
{
//Note: this method only reads lengths up to 4 bytes long as
//this is satisfactory for the majority of situations.
int length = reader.ReadByte();
if ((length & 0x00000080) == 0x00000080) //is the length greater than 1 byte
{
int count = length & 0x0000000f;
byte[] lengthBytes = new byte[4];
reader.Read(lengthBytes, 4 - count, count);
Array.Reverse(lengthBytes); //
length = BitConverter.ToInt32(lengthBytes, 0);
}
return length;
}
}
}
Java code used to sign signature data:
private static final java.security.Signature signer;
static final String transformation = "RSA/ECB/PKCS1Padding";
static {
try {
signer = java.security.Signature.getInstance("SHA1withRSA");
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
}
static String sign(String clearText) {
String signed = null;
try {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
byte[] data = clearText.getBytes("UTF-8");
signer.initSign(getPrivateKey());
signer.update(data);
byte[] digitalSignature = signer.sign();
//--toHex
signed = org.apache.commons.codec.binary.Hex.encodeHexString(digitalSignature);
} catch (Exception e) {
e.printStackTrace();
}
return signed;
}
KeyPair generateKeyPair() {
KeyPair kp = null;
// Generate a key-pair
KeyPairGenerator kpg;
SecureRandom secureRandom;
try {
kpg = KeyPairGenerator.getInstance("RSA");
secureRandom = SecureRandom.getInstance("SHA1PRNG", "SUN");
secureRandom.setSeed(secureRandomSeed);
kpg.initialize(512, secureRandom);
kp = kpg.generateKeyPair();
} catch (Exception e) {
e.printStackTrace();
}
return kp;
}
Here is code in C# that signs and verifies:
static void test3()
{
AsymmetricCipherKeyPair keys = generateNewKeys();
/* Init alg */
ISigner sig = SignerUtilities.GetSigner("SHA1withRSA");
/* Populate key */
sig.Init(true, keys.Private);
/* Get the bytes to be signed from the string */
var bytes = Encoding.UTF8.GetBytes(signData);
/* Calc the signature */
sig.BlockUpdate(bytes, 0, bytes.Length);
byte[] signature = sig.GenerateSignature();
/* Base 64 encode the sig so its 8-bit clean */
var signedString = Convert.ToBase64String(signature);
Console.WriteLine(signedString);
string expectedSignature = signedString;
/* Init alg */
ISigner signer = SignerUtilities.GetSigner("SHA1withRSA");
/* Populate key */
signer.Init(false, keys.Public);
/* Get the signature into bytes */
var expectedSig = Convert.FromBase64String(expectedSignature);
/* Get the bytes to be signed from the string */
var msgBytes = Encoding.UTF8.GetBytes(signData);
/* Calculate the signature and see if it matches */
signer.BlockUpdate(msgBytes, 0, msgBytes.Length);
/*Verify*/
bool result= signer.VerifySignature(expectedSig);
Console.WriteLine(result);
}

There's a couple problems problems here.
String signature = "770bb ... 1c7ca";
...
byte[] expectedSig = System.Convert.FromBase64String(signature);
You're Base64 decoding the signature, but it's not Base64 encoded, it's Hex encoded.
The second problem is in the DecodeX509PublicKey methods (which admittedly is my mistake because I provided this code in another answer.) The specific problem lines are
Array.Reverse(modulus); //convert to big-endian
and
Array.Reverse(exponent); //convert to big-endian
I repeatedly read that the ASN.1 and the .Net API use opposite endieness for their keys, and so I was under the impression that the endieness needed to be reversed to account for this. (I really should have done a test like your signature verification to be sure, rather than just looking at the key values in memory >.<) Regardless, remove these lines, fix the encoding problem, and your signature will verify properly (successfully tested using your sample data as well as my own).
Also, this line in your sign method isn't quite right:
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
By the time you get to that point in the code, the signer object has already been instantiated using the default provider. Also, you don't need to be adding the Bouncy Castle provider each time you want to sign some data, it will only actually add the provider the first time you make this call and will ignore it for all subsequent calls.
Further, the signer object is declaired static, but your usage of it is not thread safe.
What you more likely want to do is add the provider in the static block and then instantiate the signer explicitly using the Bouncy Castle provider. If you don't explicitly specify Bouncy Castle as the provider (or add Bouncy Castle as the highest priority using insertProviderAt), the default provider will be used instead.
static {
try {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
} catch (Exception e) {
e.printStackTrace();
}
}
...
String signed = null;
try {
java.security.Signature signer = java.security.Signature.getInstance("SHA1withRSA", "BC");
byte[] data = clearText.getBytes("UTF-8");
signer.initSign(getPrivateKey());
...

Encryption in ASP.NET that can be decrypted in MySQL with AES_DECRYPT()

I would like to be able to perform application-level encryption in ASP.NET, producing an array of bytes that would then be saved to a MySQL blob column. I would then like it to be an option that, if you have the encryption key, you would be able to decrypt it using MySQL's AES_DECRYPT() function. This seems like it should be possible, since AES_DECRYPT is an implementation of AES/Rijndael.
The MySQL AES_ENCRYPT/DECRYPT functions simply take a key and the string to encrypt/decrypt as parameters. The examples i've seen for encryption in ASP.NET/C#, however, involve also specifying values for Key and IV (initialization vector). How do these affect the final, encrypted byte array, and how can they be taken into account when decrypting with AES_DECRYPT)_?

You can do that by setting RijndaelManaged to use ECB mode.
However, ECB mode is not secure and should be avoided.
In general, a database is a very bad place to perform encryption.
If you are able to encrypt your data in the database, that implies that you have both the ciphertext and the key in the same place; this defeats the purpose of encryption.
You should keep the key as far away from ciphertext storage as possible; using any sort of SQL encryption function is usually indicative of a fundamental design flaw in your encryption strategy which can have disastrous consequences.

Encryption
In Mysql use HEX(AES_ENCRYPT('unencryptedString', 'Password'))
Example
UPDATE `secrets` SET `value`=HEX(AES_ENCRYPT('unencryptedString', 'Password')) WHERE `Id` = 2;
you will see in the database there is a value similar to this D4B5E4CAD92FFB73FCAEB5ED3B31E9EDD8FA7440E9E3F582FE5A9237DB8EE013
Now the equivalent code in C# is (Original Source:link)
public static String AES_encrypt(String Input, string key)
{
RijndaelManaged aes = new RijndaelManaged();
aes.KeySize = 128;
aes.BlockSize = 128;
aes.Mode = CipherMode.ECB;
aes.Padding = PaddingMode.PKCS7;
aes.Key = mkey(key);
aes.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
var encrypt = aes.CreateEncryptor(aes.Key, aes.IV);
byte[] xBuff = null;
using (var ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, encrypt, CryptoStreamMode.Write))
{
byte[] xXml = Encoding.UTF8.GetBytes(Input);
cs.Write(xXml, 0, xXml.Length);
cs.FlushFinalBlock();
}
xBuff = ms.ToArray();
}
return xBuff.ToHexString();
}
Helper methods and extensions that used
Refernce Link
private static byte[] mkey(string skey)
{
byte[] key = Encoding.UTF8.GetBytes(skey);
byte[] k = new byte[16] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
for (int i = 0; i < key.Length; i++)
{
k[i % 16] = (byte)(k[i % 16] ^ key[i]);
}
return k;
}
Reference Link
public static class ByteArrayExtensions
{
public static string ToHexString(this byte[] ba)
{
return BitConverter.ToString(ba).Replace("-", "");
}
}
Decryption
in Mysql use CAST(AES_DECRYPT(UNHEX(c.value), 'Password') as char)
Example
SELECT c.*,CAST(AES_DECRYPT(UNHEX(c.`value`), 'Password') as char) FROM `secrets` as c where `Id` = 2;
Equivalent code in C# is
public static String AES_decrypt(String Input, string key)
{
RijndaelManaged aes = new RijndaelManaged();
aes.KeySize = 128;
aes.BlockSize = 128;
aes.Mode = CipherMode.ECB;
aes.Padding = PaddingMode.PKCS7;
aes.Key = mkey(key);
aes.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
var decrypt = aes.CreateDecryptor();
byte[] encryptedStr = Input.FromHex2ByteArray();
string Plain_Text;
using (var ms = new MemoryStream(encryptedStr))
{
using (var cs = new CryptoStream(ms, decrypt, CryptoStreamMode.Read))
{
using (StreamReader reader = new StreamReader(cs))
{
Plain_Text = reader.ReadToEnd();
}
}
}
return Plain_Text;
}
Helper methods and extensions that used
Reference Link
private static byte[] mkey(string skey)
{
byte[] key = Encoding.UTF8.GetBytes(skey);
byte[] k = new byte[16] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
for (int i = 0; i < key.Length; i++)
{
k[i % 16] = (byte)(k[i % 16] ^ key[i]);
}
return k;
}
Reference Link
public static byte[] FromHex2ByteArray(this string hex)
{
if (hex.Length % 2 == 1)
throw new Exception("The binary key cannot have an odd number of digits");
byte[] arr = new byte[hex.Length >> 1];
for (int i = 0; i < hex.Length >> 1; ++i)
{
arr[i] = (byte)((GetHexVal(hex[i << 1]) << 4) + (GetHexVal(hex[(i << 1) + 1])));
}
return arr;
}
private static int GetHexVal(char hex)
{
int val = (int)hex;
//For uppercase A-F letters:
//return val - (val < 58 ? 48 : 55);
//For lowercase a-f letters:
//return val - (val < 58 ? 48 : 87);
//Or the two combined, but a bit slower:
return val - (val < 58 ? 48 : (val < 97 ? 55 : 87));
}

how to encrypt AES/ECB/128 messages in .Net?

Took the vectors from this site http://www.inconteam.com/software-development/41-encryption/55-aes-test-vectors#aes-ecb-128
In javascript (sjcl) have the same result
var key = [0x2b7e1516,0x28aed2a6,0xabf71588,0x09cf4f3c];
var test = [0x6bc1bee2,0x2e409f96,0xe93d7e11,0x7393172a];
aes = new sjcl.cipher.aes(key);
r = aes.encrypt(test);
console.log(r);
But I can not reach it in the C#
[TestMethod]
public void EncryptIntsToInts()
{
Int32[] key = { unchecked((Int32)0x2b7e1516), 0x28aed2a6, unchecked((Int32)0xabf71588), 0x09cf4f3c };
Int32[] test = { 0x6bc1bee2,0x2e409f96,unchecked((Int32)0xe93d7e11),0x7393172a };
Int32[] answer = { 0x3ad77bb4, 0x0d7a3660, unchecked((Int32)0xa89ecaf3), 0x2466ef97 };
var r = AES.EncryptIntsToInts(test, key.ToByteArray());
Assert.IsTrue(r.SequenceEqual(answer));
}
static byte[] zeroIV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
public static Int32[] EncryptIntsToInts(Int32[] input, byte[] key)
{
// Check arguments.
if (input == null || input.Length <= 0)
throw new ArgumentNullException("input");
if (key == null || key.Length <= 0)
throw new ArgumentNullException("key");
// Declare the RijndaelManaged object
// used to encrypt the data.
RijndaelManaged aesAlg = null;
byte[] bResult;
try
{
aesAlg = new RijndaelManaged
{
Key = key,
Mode = CipherMode.ECB,
Padding = PaddingMode.None,
KeySize = 128,
BlockSize = 128,
IV = zeroIV
};
ICryptoTransform encryptor = aesAlg.CreateEncryptor();
byte[] bInput = new byte[input.Length * sizeof(int)];
Buffer.BlockCopy(input, 0, bInput, 0, bInput.Length);
bResult = encryptor.TransformFinalBlock(bInput, 0, input.Length);
}
finally
{
if (aesAlg != null)
aesAlg.Clear();
}
int[] iResult = new int[bResult.Length / sizeof(int)];
Buffer.BlockCopy(bResult, 0, iResult, 0, bResult.Length);
return iResult;
}
What is my error?
========================================================
Start edit
New code in which right order of the bytes, but it does not work
[TestMethod]
public void EncryptIntsToInts()
{
byte[] key = "2b7e151628aed2a6abf7158809cf4f3c".HEX2Bytes();
byte[] test = "6bc1bee22e409f96e93d7e117393172a".HEX2Bytes();
byte[] answer = "3ad77bb40d7a3660a89ecaf32466ef97".HEX2Bytes();
RijndaelManaged aesAlg = new RijndaelManaged
{
Key = key,
Mode = CipherMode.ECB,
Padding = PaddingMode.PKCS7,
KeySize = 128,
BlockSize = 128,
IV = zeroIV
};
ICryptoTransform encryptor = aesAlg.CreateEncryptor();
var r = encryptor.TransformFinalBlock(test, 0, test.Length);
Assert.IsTrue(r.SequenceEqual(answer));
}
public static byte[] HEX2Bytes(this string hex)
{
if (hex.Length%2 != 0)
{
throw new ArgumentException(String.Format(CultureInfo.InvariantCulture,
"The binary key cannot have an odd number of digits: {0}", hex));
}
byte[] HexAsBytes = new byte[hex.Length/2];
for (int index = 0; index < HexAsBytes.Length; index++)
{
string byteValue = hex.Substring(index*2, 2);
HexAsBytes[index] = byte.Parse(byteValue, NumberStyles.HexNumber, CultureInfo.InvariantCulture);
}
return HexAsBytes;
}
static byte[] zeroIV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

Right code (just add a try / using):
[TestMethod]
public void EncryptIntsToInts()
{
byte[] key = "2b7e151628aed2a6abf7158809cf4f3c".HEX2Bytes();
byte[] test = "6bc1bee22e409f96e93d7e117393172a".HEX2Bytes();
byte[] answer = "3ad77bb40d7a3660a89ecaf32466ef97".HEX2Bytes();
var r = AES.Encrypt(test, key);
Assert.IsTrue(answer.SequenceEqual(r));
}
public static byte[] Encrypt(byte[] input, byte[] key)
{
var aesAlg = new AesManaged
{
KeySize = 128,
Key = key,
BlockSize = 128,
Mode = CipherMode.ECB,
Padding = PaddingMode.Zeros,
IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
};
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
return encryptor.TransformFinalBlock(input, 0, input.Length);
}

You use 32 bit integers to define the key. When you transform them to bytes, you use native endianness, which typically is little endian. So your key is 16157e2b a6... and not 2b7e1516 28....
I wouldn't use ints to represent a key in the first place. But if you really want to, write a big endian conversion function.
I also strongly recommend against ECB mode. You could use CBC together with HMAC (in an encrypt then mac construction), or use a third party lib to implement GCM.

PBKDF2 implementation in C# with Rfc2898DeriveBytes

Guys, I'm trying to implement a PBKDF2 function in C# that creates a WPA Shared key. I've found some here: http://msdn.microsoft.com/en-us/magazine/cc163913.aspx that seems to produce a valid result, but it's one byte too short... and the wrong PSK value.
To test the output, I am comparing it to this: http://www.xs4all.nl/~rjoris/wpapsk.html or http://anandam.name/pbkdf2/
I did find one way of getting this to work with a built in library to C# called Rfc2898DeriveBytes. Using this, I get a valid output using:
Rfc2898DeriveBytes k3 = new Rfc2898DeriveBytes(pwd1, salt1, 4096);
byte[] answers = k3.GetBytes(32);
Now, the one limitation I have using Rfc2898DeriveBytes is the "salt" must be 8 octets long. If it is shorter, the Rfc2898DeriveBytes throws an exception. I was thinking all I had to do was pad the salt (if it was shorter) to 8 bytes, and I'd be good. But NO! I've tried pretty much every combination of padding with a shorter salt, but I cannot duplicate the results I get from those two websites above.
So bottom line is, does this mean the Rfc2898DeriveBytes just simply won't work with a source salt shorter than 8 bytes? If so, does anyone know of any C# code I could use that implements PBKDF2 for WPA Preshared key?

Here is an implementation that does not require the 8 byte salt.
You can calculate a WPA key as follows:
Rfc2898DeriveBytes rfc2898 = new Rfc2898DeriveBytes(passphrase, Encoding.UTF8.GetBytes(name), 4096);
key = rfc2898.GetBytes(32);
public class Rfc2898DeriveBytes : DeriveBytes
{
const int BlockSize = 20;
uint block;
byte[] buffer;
int endIndex;
readonly HMACSHA1 hmacsha1;
uint iterations;
byte[] salt;
int startIndex;
public Rfc2898DeriveBytes(string password, int saltSize)
: this(password, saltSize, 1000)
{
}
public Rfc2898DeriveBytes(string password, byte[] salt)
: this(password, salt, 1000)
{
}
public Rfc2898DeriveBytes(string password, int saltSize, int iterations)
{
if (saltSize < 0)
{
throw new ArgumentOutOfRangeException("saltSize");
}
byte[] data = new byte[saltSize];
new RNGCryptoServiceProvider().GetBytes(data);
Salt = data;
IterationCount = iterations;
hmacsha1 = new HMACSHA1(new UTF8Encoding(false).GetBytes(password));
Initialize();
}
public Rfc2898DeriveBytes(string password, byte[] salt, int iterations) : this(new UTF8Encoding(false).GetBytes(password), salt, iterations)
{
}
public Rfc2898DeriveBytes(byte[] password, byte[] salt, int iterations)
{
Salt = salt;
IterationCount = iterations;
hmacsha1 = new HMACSHA1(password);
Initialize();
}
static byte[] Int(uint i)
{
byte[] bytes = BitConverter.GetBytes(i);
byte[] buffer2 = new byte[] {bytes[3], bytes[2], bytes[1], bytes[0]};
if (!BitConverter.IsLittleEndian)
{
return bytes;
}
return buffer2;
}
byte[] DeriveKey()
{
byte[] inputBuffer = Int(block);
hmacsha1.TransformBlock(salt, 0, salt.Length, salt, 0);
hmacsha1.TransformFinalBlock(inputBuffer, 0, inputBuffer.Length);
byte[] hash = hmacsha1.Hash;
hmacsha1.Initialize();
byte[] buffer3 = hash;
for (int i = 2; i <= iterations; i++)
{
hash = hmacsha1.ComputeHash(hash);
for (int j = 0; j < BlockSize; j++)
{
buffer3[j] = (byte) (buffer3[j] ^ hash[j]);
}
}
block++;
return buffer3;
}
public override byte[] GetBytes(int bytesToGet)
{
if (bytesToGet <= 0)
{
throw new ArgumentOutOfRangeException("bytesToGet");
}
byte[] dst = new byte[bytesToGet];
int dstOffset = 0;
int count = endIndex - startIndex;
if (count > 0)
{
if (bytesToGet < count)
{
Buffer.BlockCopy(buffer, startIndex, dst, 0, bytesToGet);
startIndex += bytesToGet;
return dst;
}
Buffer.BlockCopy(buffer, startIndex, dst, 0, count);
startIndex = endIndex = 0;
dstOffset += count;
}
while (dstOffset < bytesToGet)
{
byte[] src = DeriveKey();
int num3 = bytesToGet - dstOffset;
if (num3 > BlockSize)
{
Buffer.BlockCopy(src, 0, dst, dstOffset, BlockSize);
dstOffset += BlockSize;
}
else
{
Buffer.BlockCopy(src, 0, dst, dstOffset, num3);
dstOffset += num3;
Buffer.BlockCopy(src, num3, buffer, startIndex, BlockSize - num3);
endIndex += BlockSize - num3;
return dst;
}
}
return dst;
}
void Initialize()
{
if (buffer != null)
{
Array.Clear(buffer, 0, buffer.Length);
}
buffer = new byte[BlockSize];
block = 1;
startIndex = endIndex = 0;
}
public override void Reset()
{
Initialize();
}
public int IterationCount
{
get
{
return (int) iterations;
}
set
{
if (value <= 0)
{
throw new ArgumentOutOfRangeException("value");
}
iterations = (uint) value;
Initialize();
}
}
public byte[] Salt
{
get
{
return (byte[]) salt.Clone();
}
set
{
if (value == null)
{
throw new ArgumentNullException("value");
}
salt = (byte[]) value.Clone();
Initialize();
}
}
}

I get matching results when comparing key-derivation from .NET's Rfc2898DeriveBytes and Anandam's PBKDF2 Javascript implementation.
I put together an example of packaging SlowAES and Anandam's PBKDF2 into Windows Script Components. Using this implementation shows good interop with the .NET RijndaelManaged class and the Rfc2898DeriveBytes class.
See also:
AES in Javascript
Getting SlowAES and RijndaelManaged to play together
All of these go further than what you are asking for. They all show interop of the AES encryption. But to get interop on encryption, it is a necessary pre-requisite to have interop (or matching outputs) on the password-based key derivation.

Looking at the Microsoft link, I made some changes in order to make the PMK the same as those discovered in the links you put forward.
Change the SHA algorithm from SHA256Managed to SHA1Managed for the inner and outer hash.
Change HASH_SIZE_IN_BYTES to equal 20 rather than 34.
This produces the correct WPA key.
I know it's a bit late coming, but I've only just started looking for this sort of informatin and thought I could help others out. If anyone does read this post, any ideas on the PRF function and how to do it within C#?

This expands on Dodgyrabbit's answer and his code helped to fix mine as I developed this. This generic class can use any HMAC-derived class in C#. This is .NET 4 because of the parameters with default values, but if those were changed then this should work down to .NET 2, but I haven't tested that. USE AT YOUR OWN RISK.
I have also posted this on my blog, The Albequerque Left Turn, today.
using System;
using System.Text;
using System.Security.Cryptography;
namespace System.Security.Cryptography
{
//Generic PBKDF2 Class that can use any HMAC algorithm derived from the
// System.Security.Cryptography.HMAC abstract class
// PER SPEC RFC2898 with help from user Dodgyrabbit on StackExchange
// http://stackoverflow.com/questions/1046599/pbkdf2-implementation-in-c-sharp-with-rfc2898derivebytes
// the use of default values for parameters in the functions puts this at .NET 4
// if you remove those defaults and create the required constructors, you should be able to drop to .NET 2
// USE AT YOUR OWN RISK! I HAVE TESTED THIS AGAINST PUBLIC TEST VECTORS, BUT YOU SHOULD
// HAVE YOUR CODE PEER-REVIEWED AND SHOULD FOLLOW BEST PRACTICES WHEN USING CRYPTO-ANYTHING!
// NO WARRANTY IMPLIED OR EXPRESSED, YOU ARE ON YOUR OWN!
// PUBLIC DOMAIN! NO COPYRIGHT INTENDED OR RESERVED!
//constrain T to be any class that derives from HMAC, and that exposes a new() constructor
public class PBKDF2<T>: DeriveBytes where T : HMAC, new()
{
//Internal variables and public properties
private int _blockSize = -1; // the byte width of the output of the HMAC algorithm
byte[] _P = null;
int _C = 0;
private T _hmac;
byte[] _S = null;
// if you called the initializer/constructor specifying a salt size,
// you will need this property to GET the salt after it was created from the crypto rng!
// GET THIS BEFORE CALLING GETBYTES()! OBJECT WILL BE RESET AFTER GETBYTES() AND
// SALT WILL BE LOST!!
public byte[] Salt { get { return (byte[])_S.Clone(); } }
// Constructors
public PBKDF2(string Password, byte[] Salt, int IterationCount = 1000)
{ Initialize(Password, Salt, IterationCount); }
public PBKDF2(byte[] Password, byte[] Salt, int IterationCount = 1000)
{ Initialize(Password, Salt, IterationCount); }
public PBKDF2(string Password, int SizeOfSaltInBytes, int IterationCount = 1000)
{ Initialize(Password, SizeOfSaltInBytes, IterationCount);}
public PBKDF2(byte[] Password, int SizeOfSaltInBytes, int IterationCount = 1000)
{ Initialize(Password, SizeOfSaltInBytes, IterationCount);}
//All Construtors call the corresponding Initialize methods
public void Initialize(string Password, byte[] Salt, int IterationCount = 1000)
{
if (string.IsNullOrWhiteSpace(Password))
throw new ArgumentException("Password must contain meaningful characters and not be null.", "Password");
if (IterationCount < 1)
throw new ArgumentOutOfRangeException("IterationCount");
Initialize(new UTF8Encoding(false).GetBytes(Password), Salt, IterationCount);
}
public void Initialize(byte[] Password, byte[] Salt, int IterationCount = 1000)
{
//all Constructors/Initializers eventually lead to this one which does all the "important" work
if (Password == null || Password.Length == 0)
throw new ArgumentException("Password cannot be null or empty.", "Password");
if (Salt == null)
Salt = new byte[0];
if (IterationCount < 1)
throw new ArgumentOutOfRangeException("IterationCount");
_P = (byte[])Password.Clone();
_S = (byte[])Salt.Clone();
_C = IterationCount;
//determine _blockSize
_hmac = new T();
_hmac.Key = new byte[] { 0 };
byte[] test = _hmac.ComputeHash(new byte[] { 0 });
_blockSize = test.Length;
}
public void Initialize(string Password, int SizeOfSaltInBytes, int IterationCount = 1000)
{
if (string.IsNullOrWhiteSpace(Password))
throw new ArgumentException("Password must contain meaningful characters and not be null.", "Password");
if (IterationCount < 1)
throw new ArgumentOutOfRangeException("IterationCount");
Initialize(new UTF8Encoding(false).GetBytes(Password), SizeOfSaltInBytes, IterationCount);
}
public void Initialize(byte[] Password, int SizeOfSaltInBytes, int IterationCount = 1000)
{
if (Password == null || Password.Length == 0)
throw new ArgumentException("Password cannot be null or empty.", "Password");
if (SizeOfSaltInBytes < 0)
throw new ArgumentOutOfRangeException("SizeOfSaltInBytes");
if (IterationCount < 1)
throw new ArgumentOutOfRangeException("IterationCount");
// You didn't specify a salt, so I'm going to create one for you of the specific byte length
byte[] data = new byte[SizeOfSaltInBytes];
RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
rng.GetBytes(data);
// and then finish initializing...
// Get the salt from the Salt parameter BEFORE calling GetBytes()!!!!!!!!!!!
Initialize(Password, data, IterationCount);
}
~PBKDF2()
{
//*DOOT* clean up in aisle 5! *KEKERKCRACKLE*
this.Reset();
}
// required by the Derive Bytes class/interface
// this is where you request your output bytes after Initialize
// state of class Reset after use!
public override byte[] GetBytes(int ByteCount)
{
if (_S == null || _P == null)
throw new InvalidOperationException("Object not Initialized!");
if (ByteCount < 1)// || ByteCount > uint.MaxValue * blockSize)
throw new ArgumentOutOfRangeException("ByteCount");
int totalBlocks = (int)Math.Ceiling((decimal)ByteCount / _blockSize);
int partialBlock = (int)(ByteCount % _blockSize);
byte[] result = new byte[ByteCount];
byte[] buffer = null;
// I'm using TT here instead of T from the spec because I don't want to confuse it with
// the generic object T
for (int TT = 1; TT <= totalBlocks; TT++)
{
// run the F function with the _C number of iterations for block number TT
buffer = _F((uint)TT);
//IF we're not at the last block requested
//OR the last block requested is whole (not partial)
// then take everything from the result of F for this block number TT
//ELSE only take the needed bytes from F
if (TT != totalBlocks || (TT == totalBlocks && partialBlock == 0))
Buffer.BlockCopy(buffer, 0, result, _blockSize * (TT - 1), _blockSize);
else
Buffer.BlockCopy(buffer, 0, result, _blockSize * (TT - 1), partialBlock);
}
this.Reset(); // force cleanup after every use! Cannot be reused!
return result;
}
// required by the Derive Bytes class/interface
public override void Reset()
{
_C = 0;
_P.Initialize(); // the compiler might optimize this line out! :(
_P = null;
_S.Initialize(); // the compiler might optimize this line out! :(
_S = null;
if (_hmac != null)
_hmac.Clear();
_blockSize = -1;
}
// the core function of the PBKDF which does all the iterations
// per the spec section 5.2 step 3
private byte[] _F(uint I)
{
//NOTE: SPEC IS MISLEADING!!!
//THE HMAC FUNCTIONS ARE KEYED BY THE PASSWORD! NEVER THE SALT!
byte[] bufferU = null;
byte[] bufferOut = null;
byte[] _int = PBKDF2<T>.IntToBytes(I);
_hmac = new T();
_hmac.Key = (_P); // KEY BY THE PASSWORD!
_hmac.TransformBlock(_S, 0, _S.Length, _S, 0);
_hmac.TransformFinalBlock(_int, 0, _int.Length);
bufferU = _hmac.Hash;
bufferOut = (byte[])bufferU.Clone();
for (int c = 1; c < _C; c++)
{
_hmac.Initialize();
_hmac.Key = _P; // KEY BY THE PASSWORD!
bufferU = _hmac.ComputeHash(bufferU);
_Xor(ref bufferOut, bufferU);
}
return bufferOut;
}
// XOR one array of bytes into another (which is passed by reference)
// this is the equiv of data ^= newData;
private void _Xor(ref byte[] data, byte[] newData)
{
for (int i = data.GetLowerBound(0); i <= data.GetUpperBound(0); i++)
data[i] ^= newData[i];
}
// convert an unsigned int into an array of bytes BIG ENDIEN
// per the spec section 5.2 step 3
static internal byte[] IntToBytes(uint i)
{
byte[] bytes = BitConverter.GetBytes(i);
if (!BitConverter.IsLittleEndian)
{
return bytes;
}
else
{
Array.Reverse(bytes);
return bytes;
}
}
}
}

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C# (C-Sharp) is a programming language developed by Microsoft that runs on the .NET Framework.

Encryption and decryption of XML file - c#

I want to encrypt an XML file and decrypt the same in a different machine in c#. Please help...... I have already tried with RSA algorithm and RijndaelManaged key but not able to decrypt the file in different machine.

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