1、需要实现对其他系统的单点登陆，我们实现的方法很简单，就是将当前系统的账号通过加密去获取 需要直接登陆上的系统的token，然后访问需直接登陆的系统就带着token，就相当于登陆了。
2、然后呢，我们系统是 C#的，对方系统是Java的，对方给我们提供了 SM4的 加密。然后我这边也尝试去实现了下，发现sm4需要的 nuget包是 .net framework4.5以上版本，直接拿来用不行，然后就用dnSpy进行反编译。截取部分代码，试着不行，加密解密好像对不上，所以协商后准备两方采用新的加密方式，3Des加密，也就是多Des加密。
Des加密模式也是多种的，这边也采用了ECB，CBC，百度给出的解释是
ECB：电子密码本（最常用的，每次加密均产生独立的密文分组，并且对其他的密文分组不会产生影响，也就是相同的明文加密后产生相同的密文）。
CBC：密文链接（常用的，明文加密前需要先和前面的密文进行异或运算，也就是相同的明文加密后产生不同的密文）。
然后我在使用中得出大概的是ECB是直接密钥 加密，CBC相当于有一种加盐操作，除了密钥，还有iv。相当于CBC先是将明文做了偏移的操作，然后进行正常的3Des加密。
然后这边整理了C#版本和Java版本的3Des的加密解密的代码：
C#版本：
/// <summary>
/// DES3加密解密
/// </summary>
public class Des3
{
#region CBC模式**
/// <summary>
/// DES3 CBC模式加密
/// </summary>
/// <param name="key">密钥</param>
/// <param name="iv">IV</param>
/// <param name="data">明文的byte数组</param>
/// <returns>密文的byte数组</returns>
public static byte[] Des3EncodeCBC(byte[] key, byte[] iv, byte[] data)
{
//复制于MSDN
try
{
// Create a MemoryStream.
MemoryStream mStream = new MemoryStream();
TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider();
tdsp.Mode = CipherMode.CBC; //默认值
tdsp.Padding = PaddingMode.PKCS7; //默认值
// Create a CryptoStream using the MemoryStream
// and the passed key and initialization vector (IV).
CryptoStream cStream = new CryptoStream(mStream,
tdsp.CreateEncryptor(key, iv),
CryptoStreamMode.Write);
// Write the byte array to the crypto stream and flush it.
cStream.Write(data, 0, data.Length);
cStream.FlushFinalBlock();
// Get an array of bytes from the
// MemoryStream that holds the
// encrypted data.
byte[] ret = mStream.ToArray();
// Close the streams.
cStream.Close();
mStream.Close();
// Return the encrypted buffer.
return ret;
}
catch (CryptographicException e)
{
Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
return null;
}
}
/// <summary>
/// DES3 CBC模式解密
/// </summary>
/// <param name="key">密钥</param>
/// <param name="iv">IV</param>
/// <param name="data">密文的byte数组</param>
/// <returns>明文的byte数组</returns>
public static byte[] Des3DecodeCBC(byte[] key, byte[] iv, byte[] data)
{
try
{
// Create a new MemoryStream using the passed
// array of encrypted data.
MemoryStream msDecrypt = new MemoryStream(data);
TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider();
tdsp.Mode = CipherMode.CBC;
tdsp.Padding = PaddingMode.PKCS7;
// Create a CryptoStream using the MemoryStream
// and the passed key and initialization vector (IV).
CryptoStream csDecrypt = new CryptoStream(msDecrypt,
tdsp.CreateDecryptor(key, iv),
CryptoStreamMode.Read);
// Create buffer to hold the decrypted data.
byte[] fromEncrypt = new byte[data.Length];
// Read the decrypted data out of the crypto stream
// and place it into the temporary buffer.
csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);
//Convert the buffer into a string and return it.
return fromEncrypt;
}
catch (CryptographicException e)
{
Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
return null;
}
}
#endregion
#region ECB模式
/// <summary>
/// DES3 ECB模式加密
/// </summary>
/// <param name="key">密钥</param>
/// <param name="iv">IV(当模式为ECB时，IV无用)</param>
/// <param name="str">明文的byte数组</param>
/// <returns>密文的byte数组</returns>
public static byte[] Des3EncodeECB(byte[] key, byte[] iv, byte[] data)
{
try
{
// Create a MemoryStream.
MemoryStream mStream = new MemoryStream();
TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider();
tdsp.Mode = CipherMode.ECB;
tdsp.Padding = PaddingMode.PKCS7;
// Create a CryptoStream using the MemoryStream
// and the passed key and initialization vector (IV).
CryptoStream cStream = new CryptoStream(mStream,
tdsp.CreateEncryptor(key, iv),
CryptoStreamMode.Write);
// Write the byte array to the crypto stream and flush it.
cStream.Write(data, 0, data.Length);
cStream.FlushFinalBlock();
// Get an array of bytes from the
// MemoryStream that holds the
// encrypted data.
byte[] ret = mStream.ToArray();
// Close the streams.
cStream.Close();
mStream.Close();
// Return the encrypted buffer.
return ret;
}
catch (CryptographicException e)
{
Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
return null;
}
}
/// <summary>
/// DES3 ECB模式解密
/// </summary>
/// <param name="key">密钥</param>
/// <param name="iv">IV(当模式为ECB时，IV无用)</param>
/// <param name="str">密文的byte数组</param>
/// <returns>明文的byte数组</returns>
public static byte[] Des3DecodeECB(byte[] key, byte[] iv, byte[] data)
{
try
{
// Create a new MemoryStream using the passed
// array of encrypted data.
MemoryStream msDecrypt = new MemoryStream(data);
TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider();
tdsp.Mode = CipherMode.ECB;
tdsp.Padding = PaddingMode.PKCS7;
// Create a CryptoStream using the MemoryStream
// and the passed key and initialization vector (IV).
CryptoStream csDecrypt = new CryptoStream(msDecrypt,
tdsp.CreateDecryptor(key, iv),
CryptoStreamMode.Read);
// Create buffer to hold the decrypted data.
byte[] fromEncrypt = new byte[data.Length];
// Read the decrypted data out of the crypto stream
// and place it into the temporary buffer.
csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);
//Convert the buffer into a string and return it.
return fromEncrypt;
}
catch (CryptographicException e)
{
Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
return null;
}
}
#endregion
/// <summary>
/// 类测试
/// </summary>
public static void Test()
{
System.Text.Encoding utf8 = System.Text.Encoding.UTF8;
//key为abcdefghijklmnopqrstuvwx的Base64编码
byte[] key = Convert.FromBase64String("YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4");
byte[] iv = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 }; //当模式为ECB时，IV无用
byte[] data = utf8.GetBytes("中国ABCabc123");
System.Console.WriteLine("ECB模式:");
byte[] str1 = Des3.Des3EncodeECB(key, iv, data);
byte[] str2 = Des3.Des3DecodeECB(key, iv, str1);
System.Console.WriteLine(Convert.ToBase64String(str1));
System.Console.WriteLine(System.Text.Encoding.UTF8.GetString(str2));
System.Console.WriteLine();
System.Console.WriteLine("CBC模式:");
byte[] str3 = Des3.Des3EncodeCBC(key, iv, data);
byte[] str4 = Des3.Des3DecodeCBC(key, iv, str3);
System.Console.WriteLine(Convert.ToBase64String(str3));
System.Console.WriteLine(utf8.GetString(str4));
System.Console.WriteLine();
}
}
Java版本：
/**
* @Description: TODO
* @author: 王兵
* @date: 2022年02月07日 9:26
*/
import java.security.Key;
import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;
import javax.crypto.spec.IvParameterSpec;
import java.util.Base64; class Des3 {
public static void main(String[] args) throws Exception {
byte[] key= Base64.getDecoder().decode("YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4");
byte[] keyiv = { 1, 2, 3, 4, 5, 6, 7, 8 };
byte[] data="中国ABCabc123".getBytes("UTF-8"); System.out.println("ECB加密解密");
byte[] str3 = des3EncodeECB(key,data );
byte[] str4 = ees3DecodeECB(key, str3);
System.out.println(Base64.getEncoder().encodeToString(str3));
System.out.println(new String(str4, "UTF-8"));
System.out.println();
System.out.println("CBC加密解密");
byte[] str5 = des3EncodeCBC(key, keyiv, data);
byte[] str6 = des3DecodeCBC(key, keyiv, str5);
System.out.println(Base64.getEncoder().encodeToString(str5));
System.out.println(new String(str6, "UTF-8"));
}
/**
* ECB加密,不要IV
* @param key 密钥
* @param data 明文
* @return Base64编码的密文
* @throws Exception
*/
public static byte[] des3EncodeECB(byte[] key, byte[] data)
throws Exception {
Key deskey = null;
DESedeKeySpec spec = new DESedeKeySpec(key);
SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
deskey = keyfactory.generateSecret(spec);
Cipher cipher = Cipher.getInstance("desede" + "/ECB/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, deskey);
byte[] bOut = cipher.doFinal(data);
return bOut;
}
/**
* ECB解密,不要IV
* @param key 密钥
* @param data Base64编码的密文
* @return 明文
* @throws Exception
*/
public static byte[] ees3DecodeECB(byte[] key, byte[] data)
throws Exception {
Key deskey = null;
DESedeKeySpec spec = new DESedeKeySpec(key);
SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
deskey = keyfactory.generateSecret(spec);
Cipher cipher = Cipher.getInstance("desede" + "/ECB/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, deskey);
byte[] bOut = cipher.doFinal(data);
return bOut;
}
/**
* CBC加密
* @param key 密钥
* @param keyiv IV
* @param data 明文
* @return Base64编码的密文
* @throws Exception
*/
public static byte[] des3EncodeCBC(byte[] key, byte[] keyiv, byte[] data)
throws Exception {
Key deskey = null;
DESedeKeySpec spec = new DESedeKeySpec(key);
SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
deskey = keyfactory.generateSecret(spec);
Cipher cipher = Cipher.getInstance("desede" + "/CBC/PKCS5Padding");
IvParameterSpec ips = new IvParameterSpec(keyiv);
cipher.init(Cipher.ENCRYPT_MODE, deskey, ips);
byte[] bOut = cipher.doFinal(data);
return bOut;
}
/**
* CBC解密
* @param key 密钥
* @param keyiv IV
* @param data Base64编码的密文
* @return 明文
* @throws Exception
*/
public static byte[] des3DecodeCBC(byte[] key, byte[] keyiv, byte[] data)
throws Exception {
Key deskey = null;
DESedeKeySpec spec = new DESedeKeySpec(key);
SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
deskey = keyfactory.generateSecret(spec);
Cipher cipher = Cipher.getInstance("desede" + "/CBC/PKCS5Padding");
IvParameterSpec ips = new IvParameterSpec(keyiv);
cipher.init(Cipher.DECRYPT_MODE, deskey, ips);
byte[] bOut = cipher.doFinal(data);
return bOut;
}
}
