AES加解密算法(使用Base64做转码以及辅助加密)

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

/**
 * AES加解密算法(使用Base64做转码以及辅助加密)
 * 
 */
public class AES {
	private static byte[] iv = { 0, 1, 0, 2, 0, 3, 0, 4, 0, 5, 0, 6, 0, 7, 0, 8 };

	/**
	 * 加密
	 * 
	 * @param encryptString
	 * @param encryptKey 密钥
	 * @return
	 * @throws Exception
	 */
	public static String encryptAES(String encryptString, String encryptKey) throws Exception {
		IvParameterSpec zeroIv = new IvParameterSpec(iv);
		SecretKeySpec key = new SecretKeySpec(encryptKey.getBytes(), "AES");
		// 算法/模式/补码方式
		Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
		cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);
		byte[] encryptedData = cipher.doFinal(encryptString.getBytes());

		return Base64.encode(encryptedData);
	}

	/**
	 * 解密
	 * 
	 * @param decryptString
	 * @param decryptKey 密钥
	 * @return
	 * @throws Exception
	 */
	public static String decryptAES(String decryptString, String decryptKey) throws Exception {
		byte[] byteMi = Base64.decode(decryptString);
		IvParameterSpec zeroIv = new IvParameterSpec(iv);
		SecretKeySpec key = new SecretKeySpec(decryptKey.getBytes(), "AES");
		Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
		cipher.init(Cipher.DECRYPT_MODE, key, zeroIv);
		byte decryptedData[] = cipher.doFinal(byteMi);

		return new String(decryptedData);
	}
}

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public class Base64 {
	private static final char[] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();

	/**
	 * data[]进行编码
	 * 
	 * @param data
	 * @return
	 */
	public static String encode(byte[] data) {
		int start = 0;
		int len = data.length;
		StringBuffer buf = new StringBuffer(data.length * 3 / 2);

		int end = len - 3;
		int i = start;
		int n = 0;

		while (i <= end) {
			int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 0x0ff) << 8) | (((int) data[i + 2]) & 0x0ff);

			buf.append(legalChars[(d >> 18) & 63]);
			buf.append(legalChars[(d >> 12) & 63]);
			buf.append(legalChars[(d >> 6) & 63]);
			buf.append(legalChars[d & 63]);

			i += 3;

			if (n++ >= 14) {
				n = 0;
				buf.append(" ");
			}
		}

		if (i == start + len - 2) {
			int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 255) << 8);

			buf.append(legalChars[(d >> 18) & 63]);
			buf.append(legalChars[(d >> 12) & 63]);
			buf.append(legalChars[(d >> 6) & 63]);
			buf.append("=");
		} else if (i == start + len - 1) {
			int d = (((int) data[i]) & 0x0ff) << 16;

			buf.append(legalChars[(d >> 18) & 63]);
			buf.append(legalChars[(d >> 12) & 63]);
			buf.append("==");
		}

		return buf.toString();
	}

	private static int decode(char c) {
		if (c >= 'A' && c <= 'Z')
			return ((int) c) - 65;
		else if (c >= 'a' && c <= 'z')
			return ((int) c) - 97 + 26;
		else if (c >= '0' && c <= '9')
			return ((int) c) - 48 + 26 + 26;
		else
			switch (c) {
				case '+':
					return 62;
				case '/':
					return 63;
				case '=':
					return 0;
				default:
					throw new RuntimeException("unexpected code: " + c);
			}
	}

	/**
	 * Decodes the given Base64 encoded String to a new byte array. The byte array holding the decoded data is returned.
	 */
	public static byte[] decode(String s) {

		ByteArrayOutputStream bos = new ByteArrayOutputStream();
		try {
			decode(s, bos);
		} catch (IOException e) {
			throw new RuntimeException();
		}
		byte[] decodedBytes = bos.toByteArray();
		try {
			bos.close();
			bos = null;
		} catch (IOException ex) {
			System.err.println("Error while decoding BASE64: " + ex.toString());
		}
		return decodedBytes;
	}

	private static void decode(String s, OutputStream os) throws IOException {
		int i = 0;
		int len = s.length();

		while (true) {
			while (i < len && s.charAt(i) <= ' ')
				i++;

			if (i == len)
				break;

			int tri = (decode(s.charAt(i)) << 18) + (decode(s.charAt(i + 1)) << 12) + (decode(s.charAt(i + 2)) << 6) + (decode(s.charAt(i + 3)));

			os.write((tri >> 16) & 255);
			if (s.charAt(i + 2) == '=')
				break;
			os.write((tri >> 8) & 255);
			if (s.charAt(i + 3) == '=')
				break;
			os.write(tri & 255);

			i += 4;
		}
	}
}

public class Test {
	public static void main(String[] args) {
		// 密钥
		String key = "liuyq@lexinag100";
		// 文本
		String text = "{records:2,person:[{name:'Mr.Z',age:25},{name:'张三',age:29}]}";
		try {
			// 对文本进行加密
			String result1 = AES.encryptAES(text, key);
			// 对加密文本进行解密
			String result2 = AES.decryptAES(result1, key);

			System.out.println("加密前：" + text);
			System.out.println("加密后：" + result1);
			System.out.println("解密后：" + result2);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

评论

2 楼 feisuzhu 2012-10-17  

Don't roll your own.
这个是铁律。楼主要是学习目的的话，写写就好，
真正用到的话，请一定用库。

1 楼 osacar 2012-10-17  

这里DES还是AES???