目前常用的加密算法有DES（Data Encryption Standard）和IDEA（International Data Encryption Algorithm）国际数据加密算法等，请用工厂方法实现加密算法系统。
类图
源码结构：
MethodFactory
package rjsj.no3; public interface MethodFactory { public MethodFactory produceMethod(); }
IDEAFactory
package rjsj.no3; public class IDEAFactory implements MethodFactory{ @Override public MethodFactory produceMethod() { System.out.println("使用IDEA算法"); return new IDEAFactory(); } }
DESFactory
package rjsj.no3; public class DESFactory implements MethodFactory{ @Override public MethodFactory produceMethod(){ System.out.println("使用DES加密算法"); return new DESFactory(); } }
Method
package rjsj.no3; public interface Method { public abstract void work(String str,String password); }
DESMethod
package rjsj.no3; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; public class DESMethod implements Method{ @Override public void work(String str, String password) { String codeStringBegin = "吃苹果"; // 要加密的明文 String codeStringEnd = null; // 加密后的密文 String decodeString = null; // 密文解密后得到的明文 System.out.println("要加密的明文:" + codeStringBegin); String cipherType = "DESede"; // 加密算法类型，可设置为DES、DESede、AES等字符串 try { // 获取密钥生成器 KeyGenerator keyGen = KeyGenerator.getInstance(cipherType); // 初始化密钥生成器，不同的加密算法其密钥长度可能不同 keyGen.init(112); // 生成密钥 SecretKey key = keyGen.generateKey(); // 得到密钥字节码 byte[] keyByte = key.getEncoded(); // 输出密钥的字节码 System.out.println("密钥是："); for (int i = 0; i < keyByte.length; i++) { System.out.print(keyByte[i] + ","); } System.out.println(""); // 创建密码器 Cipher cp = Cipher.getInstance(cipherType); // 初始化密码器 cp.init(Cipher.ENCRYPT_MODE, key); System.out.println("要加密的字符串是：" + codeStringBegin); byte[] codeStringByte = codeStringBegin.getBytes("UTF8"); System.out.println("要加密的字符串对应的字节码是："); for (int i = 0; i < codeStringByte.length; i++) { System.out.print(codeStringByte[i] + ","); } System.out.println(""); // 开始加密 byte[] codeStringByteEnd = cp.doFinal(codeStringByte); System.out.println("加密后的字符串对应的字节码是："); for (int i = 0; i < codeStringByteEnd.length; i++) { System.out.print(codeStringByteEnd[i] + ","); } System.out.println(""); codeStringEnd = new String(codeStringByteEnd); System.out.println("加密后的字符串是：" + codeStringEnd); System.out.println(""); // 重新初始化密码器 cp.init(Cipher.DECRYPT_MODE, key); // 开始解密 byte[] decodeStringByteEnd = cp.doFinal(codeStringByteEnd); System.out.println("解密后的字符串对应的字节码是："); for (int i = 0; i < decodeStringByteEnd.length; i++) { System.out.print(decodeStringByteEnd[i] + ","); } System.out.println(""); decodeString = new String(decodeStringByteEnd,"utf-8"); System.out.println("解密后的字符串是：" + decodeString); System.out.println(""); } catch (Exception e) { e.printStackTrace(); } } public static void main(String[] args) { // TODO Auto-generated method stub System.out.println("DES加密算法"); DESMethod desMethod = new DESMethod(); try { desMethod.work("123456789", "0E329232EA6D0D73"); } catch (Exception e) { System.out.println(e.getMessage()); } } }
IDEAMethod
package rjsj.no3; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import org.apache.commons.codec.binary.Base64; import org.bouncycastle.jce.provider.BouncyCastleProvider; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import javax.crypto.spec.SecretKeySpec; import java.security.Key; import java.security.Security; public class IDEAMethod implements Method{ public static final String KEY_ALGORITHM = "IDEA"; public static final String CIPHER_ALGORITHM = "IDEA/ECB/ISO10126Padding"; public static byte[] initkey() throws Exception { // 加入bouncyCastle支持 Security.addProvider(new BouncyCastleProvider()); // 实例化密钥生成器 KeyGenerator kg = KeyGenerator.getInstance(KEY_ALGORITHM); // 初始化密钥生成器，IDEA要求密钥长度为128位 kg.init(128); // 生成密钥 SecretKey secretKey = kg.generateKey(); // 获取二进制密钥编码形式 return secretKey.getEncoded(); } /** * 转换密钥 * * @param key * 二进制密钥 * @return Key 密钥 */ private static Key toKey(byte[] key) throws Exception { // 实例化DES密钥 // 生成密钥 SecretKey secretKey = new SecretKeySpec(key, KEY_ALGORITHM); return secretKey; } /** * 加密数据 * * @param data * 待加密数据 * @param key * 密钥 * @return byte[] 加密后的数据 */ private static byte[] encrypt(byte[] data, byte[] key) throws Exception { // 加入bouncyCastle支持 Security.addProvider(new BouncyCastleProvider()); // 还原密钥 Key k = toKey(key); // 实例化 Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM); // 初始化，设置为加密模式 cipher.init(Cipher.ENCRYPT_MODE, k); // 执行操作 return cipher.doFinal(data); } /** * 解密数据 * * @param data * 待解密数据 * @param key * 密钥 * @return byte[] 解密后的数据 */ private static byte[] decrypt(byte[] data, byte[] key) throws Exception { // 加入bouncyCastle支持 Security.addProvider(new BouncyCastleProvider()); // 还原密钥 Key k = toKey(key); Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM); // 初始化，设置为解密模式 cipher.init(Cipher.DECRYPT_MODE, k); // 执行操作 return cipher.doFinal(data); } public static String getKey() { String result = null; try { result = Base64.encodeBase64String(initkey()); } catch (Exception e) { e.printStackTrace(); } return result; } public static String ideaEncrypt(String data, String key) { String result = null; try { byte[] data_en = encrypt(data.getBytes(), Base64.decodeBase64(key)); result = Base64.encodeBase64String(data_en); } catch (Exception e) { e.printStackTrace(); } return result; } public static String ideaDecrypt(String data, String key) { String result = null; try { byte[] data_de = decrypt(Base64.decodeBase64(data), Base64.decodeBase64(key)); ; result = new String(data_de); } catch (Exception e) { e.printStackTrace(); } return result; } @Override public void work(String str, String password) { String data = "吃一个葡萄"; String key = getKey(); System.out.println("要加密的原文：" + data); System.out.println("密钥：" + key); String data_en = ideaEncrypt(data, key); System.out.println("密文：" + data_en); String data_de = ideaDecrypt(data_en, key); System.out.println("原文：" + data_de); } public static void main(String[] args) { // TODO Auto-generated method stub System.out.println("IDEA加密算法"); IDEAMethod ideaMethod = new IDEAMethod(); try { ideaMethod.work("123456789", "0E329232EA6D0D73"); } catch (Exception e) { System.out.println(e.getMessage()); } } }
Main
package rjsj.no3; import java.util.Scanner; public class Main { public static void main(String[] args) { DESMethod desMethod = new DESMethod(); IDEAMethod ideaMethod = new IDEAMethod(); try{ int n = 0; Scanner in = new Scanner(System.in); while (n != 3) { System.out.println("请选择要使用的加密算法 1.DES加密算法 2.IDEA加密算法 3.退出"); System.out.println("请选择："); if (in.hasNextInt()) { n = in.nextInt(); } else { System.out.println("请重新输入整数！"); break; } switch (n) { case 1: { desMethod.work("123456789", "0E329232EA6D0D73"); break; } case 2: { ideaMethod.work("123456789", "0E329232EA6D0D73"); break; } default: System.out.println("请输入1或2！"); } } } catch (Exception e) { System.out.println(e.getMessage()); } } }
C++
#include <iostream> #include <fstream> #include <bitset> #include <string> using namespace std; bitset<64> key; // 64位密钥 bitset<48> subKey[16]; // 存放16轮子密钥 // 初始置换表 int IP[] = {58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8, 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7}; // 结尾置换表 int IP_1[] = {40, 8, 48, 16, 56, 24, 64, 32, 39, 7, 47, 15, 55, 23, 63, 31, 38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45, 13, 53, 21, 61, 29, 36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11, 51, 19, 59, 27, 34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41, 9, 49, 17, 57, 25}; /*------------------下面是生成密钥所用表-----------------*/ // 密钥置换表，将64位密钥变成56位 int PC_1[] = {57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36, 63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4}; // 压缩置换，将56位密钥压缩成48位子密钥 int PC_2[] = {14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10, 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2, 41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48, 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32}; // 每轮左移的位数 int shiftBits[] = {1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1}; /*------------------下面是密码函数 f 所用表-----------------*/ // 扩展置换表，将 32位 扩展至 48位 int E[] = {32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9, 8, 9, 10, 11, 12, 13, 12, 13, 14, 15, 16, 17, 16, 17, 18, 19, 20, 21, 20, 21, 22, 23, 24, 25, 24, 25, 26, 27, 28, 29, 28, 29, 30, 31, 32, 1}; // S盒，每个S盒是4x16的置换表，6位 -> 4位 int S_BOX[8][4][16] = { { {14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7}, {0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8}, {4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0}, {15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13} }, { {15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10}, {3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5}, {0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15}, {13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9} }, { {10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8}, {13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1}, {13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7}, {1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12} }, { {7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15}, {13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9}, {10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4}, {3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14} }, { {2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9}, {14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6}, {4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14}, {11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3} }, { {12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11}, {10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8}, {9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6}, {4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13} }, { {4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1}, {13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6}, {1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2}, {6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12} }, { {13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7}, {1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2}, {7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8}, {2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11} } }; // P置换，32位 -> 32位 int P[] = {16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10, 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25 }; /**********************************************************************/ /* */ /* 下面是DES算法实现 */ /* */ /**********************************************************************/ /** * 密码函数f，接收32位数据和48位子密钥，产生一个32位的输出 */ bitset<32> f(bitset<32> R, bitset<48> k) { bitset<48> expandR; // 第一步：扩展置换，32 -> 48 for(int i=0; i<48; ++i) expandR[47-i] = R[32-E[i]]; // 第二步：异或 expandR = expandR ^ k; // 第三步：查找S_BOX置换表 bitset<32> output; int x = 0; for(int i=0; i<48; i=i+6) { int row = expandR[47-i]*2 + expandR[47-i-5]; int col = expandR[47-i-1]*8 + expandR[47-i-2]*4 + expandR[47-i-3]*2 + expandR[47-i-4]; int num = S_BOX[i/6][row][col]; bitset<4> binary(num); output[31-x] = binary[3]; output[31-x-1] = binary[2]; output[31-x-2] = binary[1]; output[31-x-3] = binary[0]; x += 4; } // 第四步：P-置换，32 -> 32 bitset<32> tmp = output; for(int i=0; i<32; ++i) output[31-i] = tmp[32-P[i]]; return output; } /** * 对56位密钥的前后部分进行左移 */ bitset<28> leftShift(bitset<28> k, int shift) { bitset<28> tmp = k; for(int i=27; i>=0; --i) { if(i-shift<0) k[i] = tmp[i-shift+28]; else k[i] = tmp[i-shift]; } return k; } /** * 生成16个48位的子密钥 */ void generateKeys() { bitset<56> realKey; bitset<28> left; bitset<28> right; bitset<48> compressKey; // 去掉奇偶标记位，将64位密钥变成56位 for (int i=0; i<56; ++i) realKey[55-i] = key[64 - PC_1[i]]; // 生成子密钥，保存在 subKeys[16] 中 for(int round=0; round<16; ++round) { // 前28位与后28位 for(int i=28; i<56; ++i) left[i-28] = realKey[i]; for(int i=0; i<28; ++i) right[i] = realKey[i]; // 左移 left = leftShift(left, shiftBits[round]); right = leftShift(right, shiftBits[round]); // 压缩置换，由56位得到48位子密钥 for(int i=28; i<56; ++i) realKey[i] = left[i-28]; for(int i=0; i<28; ++i) realKey[i] = right[i]; for(int i=0; i<48; ++i) compressKey[47-i] = realKey[56 - PC_2[i]]; subKey[round] = compressKey; } } /** * 工具函数：将char字符数组转为二进制 */ bitset<64> charToBitset(const char s[8]) { bitset<64> bits; for(int i=0; i<8; ++i) for(int j=0; j<8; ++j) bits[i*8+j] = ((s[i]>>j) & 1); return bits; } /** * DES加密 */ bitset<64> encrypt(bitset<64>& plain) { bitset<64> cipher; bitset<64> currentBits; bitset<32> left; bitset<32> right; bitset<32> newLeft; // 第一步：初始置换IP for(int i=0; i<64; ++i) currentBits[63-i] = plain[64-IP[i]]; // 第二步：获取 Li 和 Ri for(int i=32; i<64; ++i) left[i-32] = currentBits[i]; for(int i=0; i<32; ++i) right[i] = currentBits[i]; // 第三步：共16轮迭代 for(int round=0; round<16; ++round) { newLeft = right; right = left ^ f(right,subKey[round]); left = newLeft; } // 第四步：合并L16和R16，注意合并为 R16L16 for(int i=0; i<32; ++i) cipher[i] = left[i]; for(int i=32; i<64; ++i) cipher[i] = right[i-32]; // 第五步：结尾置换IP-1 currentBits = cipher; for(int i=0; i<64; ++i) cipher[63-i] = currentBits[64-IP_1[i]]; // 返回密文 return cipher; } /** * DES解密 */ bitset<64> decrypt(bitset<64>& cipher) { bitset<64> plain; bitset<64> currentBits; bitset<32> left; bitset<32> right; bitset<32> newLeft; // 第一步：初始置换IP for(int i=0; i<64; ++i) currentBits[63-i] = cipher[64-IP[i]]; // 第二步：获取 Li 和 Ri for(int i=32; i<64; ++i) left[i-32] = currentBits[i]; for(int i=0; i<32; ++i) right[i] = currentBits[i]; // 第三步：共16轮迭代（子密钥逆序应用） for(int round=0; round<16; ++round) { newLeft = right; right = left ^ f(right,subKey[15-round]); left = newLeft; } // 第四步：合并L16和R16，注意合并为 R16L16 for(int i=0; i<32; ++i) plain[i] = left[i]; for(int i=32; i<64; ++i) plain[i] = right[i-32]; // 第五步：结尾置换IP-1 currentBits = plain; for(int i=0; i<64; ++i) plain[63-i] = currentBits[64-IP_1[i]]; // 返回明文 return plain; } class Method{ public: void work(){} }; class DES:public Method{ public: DES(){ cout<<"DES加密算法"<<endl; work(); } void work(){ string s = "常金悦"; string k = "12345678"; bitset<64> temp; fstream file1; bitset<64> plain = charToBitset(s.c_str()); key = charToBitset(k.c_str()); // 生成16个子密钥 generateKeys(); // 密文写入 a.txt bitset<64> cipher = encrypt(plain); file1.open(".//a.txt", ios::binary | ios::out); file1.write((char*)&cipher,sizeof(cipher)); file1.close(); // 读文件 a.txt file1.open(".//a.txt", ios::binary | ios::in); file1.read((char*)&temp, sizeof(temp)); cout<<"密文 "<<(char*)&temp<<endl; file1.close(); // 解密，并写入文件 b.txt bitset<64> temp_plain = decrypt(cipher); cout<<"解密 "<<(char*)&temp_plain<<endl; } }; class MethodFactory{ Method getMethod(){}; }; class DESFactory:public MethodFactory{ public: DES getMethod(){ cout<<"DES加密算法"<<endl; DES des; return des; } }; int main() { DES des; return 0; }