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Android RSA加密解密

Android RSA加密解密

 

概述

RSA是目前最有影响力的公钥加密算法,该算法基于一个十分简单的数论事实:将两个大素数相乘十分容易,但那时想要对其乘积进行因式分解却极其困 难,因此可以将乘积公开作为加密密钥,即公钥,而两个大素数组合成私钥。公钥是可发布的供任何人使用,私钥则为自己所有,供解密之用。关于RSA其它需要了解的知识,参考维基百科:http://zh.wikipedia.org/zh-cn/RSA%E5%8A%A0%E5%AF%86%E6%BC%94%E7%AE%97%E6%B3%95

在项目开发中对于一些比较敏感的信息需要对其进行加密处理,我们就可以使用RSA这种非对称加密算法来对数据进行加密处理。

 

使用

秘钥对的生成

1、我们可以在代码里随机生成密钥对

 

	/**
	 * 随机生成RSA密钥对
	 * 
	 * @param keyLength
	 *            密钥长度,范围:512~2048

	 *            一般1024
	 * @return
	 */
	public static KeyPair generateRSAKeyPair(int keyLength)
	{
		try
		{
			KeyPairGenerator kpg = KeyPairGenerator.getInstance(RSA);
			kpg.initialize(keyLength);
			return kpg.genKeyPair();
		} catch (NoSuchAlgorithmException e)
		{
			e.printStackTrace();
			return null;
		}
	}

通过这方法我们得到KeyPair后就可以调用 keyPair.getPrivate() 和 pair.getPublic()得到 私钥 和 公钥了。不过实际我们一般是使用2的方法把生成的密钥对保存起来,密钥自己保存,比如服务端,把公钥给客户端(Android)用于加密需要发送的数据,最后服务端根据私钥吧客户端加密的信息解密再处理。

 

2、通过OpenSSl工具生成密钥对

OpenSSl工具下载:OpenSSl工具 (64位的也可使用)使用OpenSSl工具生成密钥对的过程如下:

首先双击打开bin文件夹下的openssl.exe,打开之后是一个命令行窗口:

然后通过如下命令生成私钥:

 

genrsa -out rsa_private_key.pem 1024

 

这条命令是让openssl随机生成了一份私钥,加密长度是1024位, 密钥长度,范围:512~2048。执行完命令后就可在bin文件夹下看到rsa_private_key.pem文件了。

 

用文本类工具打开可看到里面的内容:

 

-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----

这里面的内容是标准的ASCII字符,中间的一大串字符就是私钥数据了。

 

 

然后通过如下命令生成公钥:

 

rsa -in rsa_private_key.pem -out rsa_public_key.pem -pubout

 


打开文件看下里面的内容:

 

-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCfRTdcPIH10gT9f31rQuIInLwe
7fl2dtEJ93gTmjE9c2H+kLVENWgECiJVQ5sonQNfwToMKdO0b3Olf4pgBKeLThra
z/L3nYJYlbqjHC3jTjUnZc0luumpXGsox62+PuSGBlfb8zJO6hix4GV/vhyQVCpG
9aYqgE7zyTRZYX9byQIDAQAB
-----END PUBLIC KEY-----

可以看到是跟私钥的文件类似的。

 

 

这样密钥就基本生成了,不过这样密钥对的私钥是无法在代码中直接使用的,要想使用它需要借助RSAPrivateKeyStructure这个类,java是不自带的。所以为了方便使用,我们需要对私钥进行PKCS#8编码,命令如下:

 

pkcs8 -topk8 -in rsa_private_key.pem -out pkcs8_rsa_private_key.pem -nocrypt  

 


这条命令的结果依然是在bin文件夹生成了pkcs8_rsa_private_key.pem文件,打开内容如下:

 

-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----

可以看到中间的私钥内容有所变化了,这样的私钥我们在代码里就方便使用了。

 

 

以上的密钥文件使用时需要注意吧头和尾的字符串去掉,我们只取中间的内容。

 

代码中的使用

首先我们需要封装写个RSA的工具类,方便加密解密的操作。

 

package com.example.rsa;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.RSAPublicKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.Cipher;

/**
 * @author Mr.Zheng
 * @date 2014年8月22日 下午1:44:23
 */
public final class RSAUtils
{
	private static String RSA = RSA;

	/**
	 * 随机生成RSA密钥对(默认密钥长度为1024)
	 * 
	 * @return
	 */
	public static KeyPair generateRSAKeyPair()
	{
		return generateRSAKeyPair(1024);
	}

	/**
	 * 随机生成RSA密钥对
	 * 
	 * @param keyLength
	 *            密钥长度,范围:512~2048

	 *            一般1024
	 * @return
	 */
	public static KeyPair generateRSAKeyPair(int keyLength)
	{
		try
		{
			KeyPairGenerator kpg = KeyPairGenerator.getInstance(RSA);
			kpg.initialize(keyLength);
			return kpg.genKeyPair();
		} catch (NoSuchAlgorithmException e)
		{
			e.printStackTrace();
			return null;
		}
	}

	/**
	 * 用公钥加密 

	 * 每次加密的字节数,不能超过密钥的长度值减去11
	 * 
	 * @param data
	 *            需加密数据的byte数据
	 * @param pubKey
	 *            公钥
	 * @return 加密后的byte型数据
	 */
	public static byte[] encryptData(byte[] data, PublicKey publicKey)
	{
		try
		{
			Cipher cipher = Cipher.getInstance(RSA);
			// 编码前设定编码方式及密钥
			cipher.init(Cipher.ENCRYPT_MODE, publicKey);
			// 传入编码数据并返回编码结果
			return cipher.doFinal(data);
		} catch (Exception e)
		{
			e.printStackTrace();
			return null;
		}
	}

	/**
	 * 用私钥解密
	 * 
	 * @param encryptedData
	 *            经过encryptedData()加密返回的byte数据
	 * @param privateKey
	 *            私钥
	 * @return
	 */
	public static byte[] decryptData(byte[] encryptedData, PrivateKey privateKey)
	{
		try
		{
			Cipher cipher = Cipher.getInstance(RSA);
			cipher.init(Cipher.DECRYPT_MODE, privateKey);
			return cipher.doFinal(encryptedData);
		} catch (Exception e)
		{
			return null;
		}
	}

	/**
	 * 通过公钥byte[](publicKey.getEncoded())将公钥还原,适用于RSA算法
	 * 
	 * @param keyBytes
	 * @return
	 * @throws NoSuchAlgorithmException
	 * @throws InvalidKeySpecException
	 */
	public static PublicKey getPublicKey(byte[] keyBytes) throws NoSuchAlgorithmException,
			InvalidKeySpecException
	{
		X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(RSA);
		PublicKey publicKey = keyFactory.generatePublic(keySpec);
		return publicKey;
	}

	/**
	 * 通过私钥byte[]将公钥还原,适用于RSA算法
	 * 
	 * @param keyBytes
	 * @return
	 * @throws NoSuchAlgorithmException
	 * @throws InvalidKeySpecException
	 */
	public static PrivateKey getPrivateKey(byte[] keyBytes) throws NoSuchAlgorithmException,
			InvalidKeySpecException
	{
		PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(RSA);
		PrivateKey privateKey = keyFactory.generatePrivate(keySpec);
		return privateKey;
	}

	/**
	 * 使用N、e值还原公钥
	 * 
	 * @param modulus
	 * @param publicExponent
	 * @return
	 * @throws NoSuchAlgorithmException
	 * @throws InvalidKeySpecException
	 */
	public static PublicKey getPublicKey(String modulus, String publicExponent)
			throws NoSuchAlgorithmException, InvalidKeySpecException
	{
		BigInteger bigIntModulus = new BigInteger(modulus);
		BigInteger bigIntPrivateExponent = new BigInteger(publicExponent);
		RSAPublicKeySpec keySpec = new RSAPublicKeySpec(bigIntModulus, bigIntPrivateExponent);
		KeyFactory keyFactory = KeyFactory.getInstance(RSA);
		PublicKey publicKey = keyFactory.generatePublic(keySpec);
		return publicKey;
	}

	/**
	 * 使用N、d值还原私钥
	 * 
	 * @param modulus
	 * @param privateExponent
	 * @return
	 * @throws NoSuchAlgorithmException
	 * @throws InvalidKeySpecException
	 */
	public static PrivateKey getPrivateKey(String modulus, String privateExponent)
			throws NoSuchAlgorithmException, InvalidKeySpecException
	{
		BigInteger bigIntModulus = new BigInteger(modulus);
		BigInteger bigIntPrivateExponent = new BigInteger(privateExponent);
		RSAPublicKeySpec keySpec = new RSAPublicKeySpec(bigIntModulus, bigIntPrivateExponent);
		KeyFactory keyFactory = KeyFactory.getInstance(RSA);
		PrivateKey privateKey = keyFactory.generatePrivate(keySpec);
		return privateKey;
	}

	/**
	 * 从字符串中加载公钥
	 * 
	 * @param publicKeyStr
	 *            公钥数据字符串
	 * @throws Exception
	 *             加载公钥时产生的异常
	 */
	public static PublicKey loadPublicKey(String publicKeyStr) throws Exception
	{
		try
		{
			byte[] buffer = Base64Utils.decode(publicKeyStr);
			KeyFactory keyFactory = KeyFactory.getInstance(RSA);
			X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);
			return (RSAPublicKey) keyFactory.generatePublic(keySpec);
		} catch (NoSuchAlgorithmException e)
		{
			throw new Exception(无此算法);
		} catch (InvalidKeySpecException e)
		{
			throw new Exception(公钥非法);
		} catch (NullPointerException e)
		{
			throw new Exception(公钥数据为空);
		}
	}

	/**
	 * 从字符串中加载私钥

	 * 加载时使用的是PKCS8EncodedKeySpec(PKCS#8编码的Key指令)。
	 * 
	 * @param privateKeyStr
	 * @return
	 * @throws Exception
	 */
	public static PrivateKey loadPrivateKey(String privateKeyStr) throws Exception
	{
		try
		{
			byte[] buffer = Base64Utils.decode(privateKeyStr);
			// X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);
			PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
			KeyFactory keyFactory = KeyFactory.getInstance(RSA);
			return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
		} catch (NoSuchAlgorithmException e)
		{
			throw new Exception(无此算法);
		} catch (InvalidKeySpecException e)
		{
			throw new Exception(私钥非法);
		} catch (NullPointerException e)
		{
			throw new Exception(私钥数据为空);
		}
	}

	/**
	 * 从文件中输入流中加载公钥
	 * 
	 * @param in
	 *            公钥输入流
	 * @throws Exception
	 *             加载公钥时产生的异常
	 */
	public static PublicKey loadPublicKey(InputStream in) throws Exception
	{
		try
		{
			return loadPublicKey(readKey(in));
		} catch (IOException e)
		{
			throw new Exception(公钥数据流读取错误);
		} catch (NullPointerException e)
		{
			throw new Exception(公钥输入流为空);
		}
	}

	/**
	 * 从文件中加载私钥
	 * 
	 * @param keyFileName
	 *            私钥文件名
	 * @return 是否成功
	 * @throws Exception
	 */
	public static PrivateKey loadPrivateKey(InputStream in) throws Exception
	{
		try
		{
			return loadPrivateKey(readKey(in));
		} catch (IOException e)
		{
			throw new Exception(私钥数据读取错误);
		} catch (NullPointerException e)
		{
			throw new Exception(私钥输入流为空);
		}
	}

	/**
	 * 读取密钥信息
	 * 
	 * @param in
	 * @return
	 * @throws IOException
	 */
	private static String readKey(InputStream in) throws IOException
	{
		BufferedReader br = new BufferedReader(new InputStreamReader(in));
		String readLine = null;
		StringBuilder sb = new StringBuilder();
		while ((readLine = br.readLine()) != null)
		{
			if (readLine.charAt(0) == '-')
			{
				continue;
			} else
			{
				sb.append(readLine);
				sb.append('
');
			}
		}

		return sb.toString();
	}

	/**
	 * 打印公钥信息
	 * 
	 * @param publicKey
	 */
	public static void printPublicKeyInfo(PublicKey publicKey)
	{
		RSAPublicKey rsaPublicKey = (RSAPublicKey) publicKey;
		System.out.println(----------RSAPublicKey----------);
		System.out.println(Modulus.length= + rsaPublicKey.getModulus().bitLength());
		System.out.println(Modulus= + rsaPublicKey.getModulus().toString());
		System.out.println(PublicExponent.length= + rsaPublicKey.getPublicExponent().bitLength());
		System.out.println(PublicExponent= + rsaPublicKey.getPublicExponent().toString());
	}

	public static void printPrivateKeyInfo(PrivateKey privateKey)
	{
		RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) privateKey;
		System.out.println(----------RSAPrivateKey ----------);
		System.out.println(Modulus.length= + rsaPrivateKey.getModulus().bitLength());
		System.out.println(Modulus= + rsaPrivateKey.getModulus().toString());
		System.out.println(PrivateExponent.length= + rsaPrivateKey.getPrivateExponent().bitLength());
		System.out.println(PrivatecExponent= + rsaPrivateKey.getPrivateExponent().toString());

	}

}

 

上面需要注意的就是加密是有长度限制的,过长的话会抛异常!!!


代码中有些需要使用Base64再转换的,而java中不自带,Android中自带,所以自己写出一个来,方便Java后台使用

 

package com.example.rsa;

import java.io.UnsupportedEncodingException;

/**
 * @author Mr.Zheng
 * @date 2014年8月22日 下午9:50:28
 */
public class Base64Utils
{
	private static char[] base64EncodeChars = new char[]
	{ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
			'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
			'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5',
			'6', '7', '8', '9', '+', '/' };
	private static byte[] base64DecodeChars = new byte[]
	{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
			-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53,
			54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
			12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29,
			30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1,
			-1, -1, -1 };

	/**
	 * 加密
	 * 
	 * @param data
	 * @return
	 */
	public static String encode(byte[] data)
	{
		StringBuffer sb = new StringBuffer();
		int len = data.length;
		int i = 0;
		int b1, b2, b3;
		while (i < len)
		{
			b1 = data[i++] & 0xff;
			if (i == len)
			{
				sb.append(base64EncodeChars[b1 >>> 2]);
				sb.append(base64EncodeChars[(b1 & 0x3) << 4]);
				sb.append(==);
				break;
			}
			b2 = data[i++] & 0xff;
			if (i == len)
			{
				sb.append(base64EncodeChars[b1 >>> 2]);
				sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
				sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);
				sb.append(=);
				break;
			}
			b3 = data[i++] & 0xff;
			sb.append(base64EncodeChars[b1 >>> 2]);
			sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
			sb.append(base64EncodeChars[((b2 & 0x0f) << 2) | ((b3 & 0xc0) >>> 6)]);
			sb.append(base64EncodeChars[b3 & 0x3f]);
		}
		return sb.toString();
	}

	/**
	 * 解密
	 * 
	 * @param str
	 * @return
	 */
	public static byte[] decode(String str)
	{
		try
		{
			return decodePrivate(str);
		} catch (UnsupportedEncodingException e)
		{
			e.printStackTrace();
		}
		return new byte[]
		{};
	}

	private static byte[] decodePrivate(String str) throws UnsupportedEncodingException
	{
		StringBuffer sb = new StringBuffer();
		byte[] data = null;
		data = str.getBytes(US-ASCII);
		int len = data.length;
		int i = 0;
		int b1, b2, b3, b4;
		while (i < len)
		{

			do
			{
				b1 = base64DecodeChars[data[i++]];
			} while (i < len && b1 == -1);
			if (b1 == -1)
				break;

			do
			{
				b2 = base64DecodeChars[data[i++]];
			} while (i < len && b2 == -1);
			if (b2 == -1)
				break;
			sb.append((char) ((b1 << 2) | ((b2 & 0x30) >>> 4)));

			do
			{
				b3 = data[i++];
				if (b3 == 61)
					return sb.toString().getBytes(iso8859-1);
				b3 = base64DecodeChars[b3];
			} while (i < len && b3 == -1);
			if (b3 == -1)
				break;
			sb.append((char) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));

			do
			{
				b4 = data[i++];
				if (b4 == 61)
					return sb.toString().getBytes(iso8859-1);
				b4 = base64DecodeChars[b4];
			} while (i < len && b4 == -1);
			if (b4 == -1)
				break;
			sb.append((char) (((b3 & 0x03) << 6) | b4));
		}
		return sb.toString().getBytes(iso8859-1);
	}

}

最后就是真正使用它们了:

 

 

package com.example.rsa;

import java.io.InputStream;
import java.security.PrivateKey;
import java.security.PublicKey;

import android.app.Activity;
import android.os.Bundle;
import android.util.Base64;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends Activity implements OnClickListener
{
	private Button btn1, btn2;// 加密,解密
	private EditText et1, et2, et3;// 需加密的内容,加密后的内容,解密后的内容

	/* 密钥内容 base64 code */
	private static String PUCLIC_KEY = MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCfRTdcPIH10gT9f31rQuIInLwe
			+ 
 + 7fl2dtEJ93gTmjE9c2H+kLVENWgECiJVQ5sonQNfwToMKdO0b3Olf4pgBKeLThra + 

			+ z/L3nYJYlbqjHC3jTjUnZc0luumpXGsox62+PuSGBlfb8zJO6hix4GV/vhyQVCpG + 

			+ 9aYqgE7zyTRZYX9byQIDAQAB + 
;
	private static String PRIVATE_KEY = MIICdwIBADANBgkqhkiG9w0BAQEFAASCAmEwggJdAgEAAoGBAJ9FN1w8gfXSBP1/
			+ 
 + fWtC4gicvB7t+XZ20Qn3eBOaMT1zYf6QtUQ1aAQKIlVDmyidA1/BOgwp07Rvc6V/ + 

			+ imAEp4tOGtrP8vedgliVuqMcLeNONSdlzSW66alcayjHrb4+5IYGV9vzMk7qGLHg + 

			+ ZX++HJBUKkb1piqATvPJNFlhf1vJAgMBAAECgYA736xhG0oL3EkN9yhx8zG/5RP/ + 

			+ WJzoQOByq7pTPCr4m/Ch30qVerJAmoKvpPumN+h1zdEBk5PHiAJkm96sG/PTndEf + 

			+ kZrAJ2hwSBqptcABYk6ED70gRTQ1S53tyQXIOSjRBcugY/21qeswS3nMyq3xDEPK + 

			+ XpdyKPeaTyuK86AEkQJBAM1M7p1lfzEKjNw17SDMLnca/8pBcA0EEcyvtaQpRvaL + 

			+ n61eQQnnPdpvHamkRBcOvgCAkfwa1uboru0QdXii/gUCQQDGmkP+KJPX9JVCrbRt + 

			+ 7wKyIemyNM+J6y1ZBZ2bVCf9jacCQaSkIWnIR1S9UM+1CFE30So2CA0CfCDmQy+y + 

			+ 7A31AkB8cGFB7j+GTkrLP7SX6KtRboAU7E0q1oijdO24r3xf/Imw4Cy0AAIx4KAu + 

			+ L29GOp1YWJYkJXCVTfyZnRxXHxSxAkEAvO0zkSv4uI8rDmtAIPQllF8+eRBT/deD + 

			+ JBR7ga/k+wctwK/Bd4Fxp9xzeETP0l8/I+IOTagK+Dos8d8oGQUFoQJBAI4Nwpfo + 

			+ MFaLJXGY9ok45wXrcqkJgM+SN6i8hQeujXESVHYatAIL/1DgLi+u46EFD69fw0w+ + 
 + c7o0HLlMsYPAzJw=
			+ 
;

	@Override
	protected void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		initView();
	}

	private void initView()
	{
		btn1 = (Button) findViewById(R.id.btn1);
		btn2 = (Button) findViewById(R.id.btn2);
		btn1.setOnClickListener(this);
		btn2.setOnClickListener(this);

		et1 = (EditText) findViewById(R.id.et1);
		et2 = (EditText) findViewById(R.id.et2);
		et3 = (EditText) findViewById(R.id.et3);
	}

	@Override
	public void onClick(View v)
	{
		switch (v.getId())
		{
		// 加密
		case R.id.btn1:
			String source = et1.getText().toString().trim();
			try
			{
				// 从字符串中得到公钥
				// PublicKey publicKey = RSAUtils.loadPublicKey(PUCLIC_KEY);
				// 从文件中得到公钥
				InputStream inPublic = getResources().getAssets().open(rsa_public_key.pem);
				PublicKey publicKey = RSAUtils.loadPublicKey(inPublic);
				// 加密
				byte[] encryptByte = RSAUtils.encryptData(source.getBytes(), publicKey);
				// 为了方便观察吧加密后的数据用base64加密转一下,要不然看起来是乱码,所以解密是也是要用Base64先转换
				String afterencrypt = Base64Utils.encode(encryptByte);
				et2.setText(afterencrypt);
			} catch (Exception e)
			{
				e.printStackTrace();
			}
			break;
		// 解密
		case R.id.btn2:
			String encryptContent = et2.getText().toString().trim();
			try
			{
				// 从字符串中得到私钥
				// PrivateKey privateKey = RSAUtils.loadPrivateKey(PRIVATE_KEY);
				// 从文件中得到私钥
				InputStream inPrivate = getResources().getAssets().open(pkcs8_rsa_private_key.pem);
				PrivateKey privateKey = RSAUtils.loadPrivateKey(inPrivate);
				// 因为RSA加密后的内容经Base64再加密转换了一下,所以先Base64解密回来再给RSA解密
				byte[] decryptByte = RSAUtils.decryptData(Base64Utils.decode(encryptContent), privateKey);
				String decryptStr = new String(decryptByte);
				et3.setText(decryptStr);
			} catch (Exception e)
			{
				e.printStackTrace();
			}
			break;
		default:
			break;
		}
	}

}

我把密钥放到assest资源文件夹里了,也可以直接使用字符串得到,上面注释掉了。

 

最后我们来看下效果吧:

 

源码下载地址:http://download.csdn.net/detail/bbld_/7806673

 

http://www.bkjia.com/Androidjc/868958.htmlwww.bkjia.comtruehttp://www.bkjia.com/Androidjc/868958.htmlTechArticleAndroid RSA加密解密 概述 RSA是目前最有影响力的公钥加密算法,该算法基于一个十分简单的数论事实:将两个大素数相乘十分容易,但那时想...

本文源自: AG88环亚

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