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  1. import java.util.*;
  2. import java.lang.*;
  3. import java.security.SecureRandom;
  4. import javax.crypto.spec.SecretKeySpec;
  5. import javax.crypto.Cipher;
  6. import javax.crypto.SecretKey;
  7.  
  8. class Main
  9. {
  10.  
  11.     static final int ENCRYPT = -1;
  12.     static final int DECRYPT = -2;
  13.  
  14.     static byte[] encodeData;
  15.     static String charSet = 
  16.   "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  17.  
  18.     static {
  19.     	encodeData = new byte[64];
  20. 	for (int i = 0; i<64; i++) {
  21. 	    byte c = (byte) charSet.charAt(i);
  22. 	    encodeData[i] = c;
  23. 	}
  24.     }
  25.  
  26. 	public static void main (String[] args) throws java.lang.Exception
  27. 	{
  28. 		String ct = aes128("123", "hello", ENCRYPT );
  29.                 System.out.println(ct);
  30.  
  31.                 // should produce a different result
  32. 		ct = aes128("123", "hello", ENCRYPT );
  33.                 System.out.println(ct);
  34.  
  35.                 // attempting to decrypt
  36.                 System.out.println(aes128("123", ct, DECRYPT));
  37.  
  38. 	}
  39.  
  40. public static String aes128(String key, String data, final int direction) {
  41.     SecureRandom rand = new SecureRandom(key.getBytes());
  42.     byte[] randBytes = new byte[16];
  43.     rand.nextBytes(randBytes);
  44.     SecretKey encKey = new SecretKeySpec(randBytes, "AES");
  45.  
  46.     Cipher cipher = null;
  47.     try {
  48.         cipher = Cipher.getInstance("AES");
  49.         cipher.init((direction == ENCRYPT ? Cipher.ENCRYPT_MODE : Cipher.DECRYPT_MODE), encKey);
  50.     } catch (Exception e) {
  51.         return null;
  52.     } 
  53.  
  54.     try {
  55.         if (direction == ENCRYPT) {
  56.             byte[] encVal = cipher.doFinal(data.getBytes());
  57.             return encode(encVal);
  58.         } else {
  59.             byte[] dataBytes = decode(data);
  60.             byte[] encVal = cipher.doFinal(dataBytes);
  61.             return new String(encVal);
  62.         }
  63.     } catch (Exception e) {
  64. e.printStackTrace();
  65.         return null;
  66.     } 
  67. }
  68.  
  69.  
  70.     public static String
  71.     encode(String s) {
  72.         return encode(s.getBytes());
  73.     }
  74.  
  75.     /**
  76.      * base-64 encode a byte array
  77.      * @param src	The byte array to encode
  78.      * @returns		The base64 encoded result
  79.      */
  80.  
  81.     public static String
  82.     encode(byte[] src) {
  83. 	return encode(src, 0, src.length);
  84.     }
  85.  
  86.     /**
  87.      * base-64 encode a byte array
  88.      * @param src	The byte array to encode
  89.      * @param start	The starting index
  90.      * @param len	The number of bytes
  91.      * @returns		The base64 encoded result
  92.      */
  93.  
  94.     public static String
  95.     encode(byte[] src, int start, int length) {
  96.         byte[] dst = new byte[(length+2)/3 * 4 + length/72];
  97.         int x = 0;
  98.         int dstIndex = 0;
  99.         int state = 0;	// which char in pattern
  100.         int old = 0;	// previous byte
  101.         int len = 0;	// length decoded so far
  102. 	int max = length + start;
  103.         for (int srcIndex = start; srcIndex<max; srcIndex++) {
  104. 	    x = src[srcIndex];
  105. 	    switch (++state) {
  106. 	    case 1:
  107. 	        dst[dstIndex++] = encodeData[(x>>2) & 0x3f];
  108. 		break;
  109. 	    case 2:
  110. 	        dst[dstIndex++] = encodeData[((old<<4)&0x30) 
  111. 	            | ((x>>4)&0xf)];
  112. 		break;
  113. 	    case 3:
  114. 	        dst[dstIndex++] = encodeData[((old<<2)&0x3C) 
  115. 	            | ((x>>6)&0x3)];
  116. 		dst[dstIndex++] = encodeData[x&0x3F];
  117. 		state = 0;
  118. 		break;
  119. 	    }
  120. 	    old = x;
  121. 	    if (++len >= 72) {
  122. 	    	dst[dstIndex++] = (byte) '\n';
  123. 	    	len = 0;
  124. 	    }
  125. 	}
  126.  
  127. 	/*
  128. 	 * now clean up the end bytes
  129. 	 */
  130.  
  131. 	switch (state) {
  132. 	case 1: dst[dstIndex++] = encodeData[(old<<4) & 0x30];
  133. 	   dst[dstIndex++] = (byte) '=';
  134. 	   dst[dstIndex++] = (byte) '=';
  135. 	   break;
  136. 	case 2: dst[dstIndex++] = encodeData[(old<<2) & 0x3c];
  137. 	   dst[dstIndex++] = (byte) '=';
  138. 	   break;
  139. 	}
  140. 	return new String(dst);
  141.     }
  142.  
  143.     /**
  144.      * A Base64 decoder.  This implementation is slow, and 
  145.      * doesn't handle wrapped lines.
  146.      * The output is undefined if there are errors in the input.
  147.      * @param s		a Base64 encoded string
  148.      * @returns		The byte array eith the decoded result
  149.      */
  150.  
  151.     public static byte[]
  152.     decode(String s) {
  153.       int end = 0;	// end state
  154.       if (s.endsWith("=")) {
  155. 	  end++;
  156.       }
  157.       if (s.endsWith("==")) {
  158. 	  end++;
  159.       }
  160.       int len = (s.length() + 3)/4 * 3 - end;
  161.       byte[] result = new byte[len];
  162.       int dst = 0;
  163.       try {
  164. 	  for(int src = 0; src< s.length(); src++) {
  165. 	      int code =  charSet.indexOf(s.charAt(src));
  166. 	      if (code == -1) {
  167. 	          break;
  168. 	      }
  169. 	      switch (src%4) {
  170. 	      case 0:
  171. 	          result[dst] = (byte) (code<<2);
  172. 	          break;
  173. 	      case 1: 
  174. 	          result[dst++] |= (byte) ((code>>4) & 0x3);
  175. 	          result[dst] = (byte) (code<<4);
  176. 	          break;
  177. 	      case 2:
  178. 	          result[dst++] |= (byte) ((code>>2) & 0xf);
  179. 	          result[dst] = (byte) (code<<6);
  180. 	          break;
  181. 	      case 3:
  182. 	          result[dst++] |= (byte) (code & 0x3f);
  183. 	          break;
  184. 	      }
  185. 	  }
  186.       } catch (ArrayIndexOutOfBoundsException e) {}
  187.       return result;
  188.     }
  189.  
  190. }
Success #stdin #stdout 0.33s 216960KB
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zeMpipdoIfpMdEGpo/smPQ==
a4MHuUP/gr3SYqcp0JRlwA==
null
https://ideone.com/jOyAQ
language:
Java (12.0.1)
created:
11 years ago
visibility:
public

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