Java使用RSA加密解密签名及校验

由于项目要用到非对称加密解密签名校验什么的，于是参考《Java加密解密的艺术》写一个RSA进行加密解密签名及校验的Demo，代码很简单，特此分享！

RSA加密解密类：

package com.ihep;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;

import com.fcplay.Base64;

public class RSAEncrypt {
	/**
	 * 字节数据转字符串专用集合
	 */
	private static final char[] HEX_CHAR = { ‘0‘, ‘1‘, ‘2‘, ‘3‘, ‘4‘, ‘5‘, ‘6‘,
			‘7‘, ‘8‘, ‘9‘, ‘a‘, ‘b‘, ‘c‘, ‘d‘, ‘e‘, ‘f‘ };

	/**
	 * 随机生成密钥对
	 */
	public static void genKeyPair(String filePath) {
		// KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
		KeyPairGenerator keyPairGen = null;
		try {
			keyPairGen = KeyPairGenerator.getInstance("RSA");
		} catch (NoSuchAlgorithmException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		// 初始化密钥对生成器，密钥大小为96-1024位
		keyPairGen.initialize(1024,new SecureRandom());
		// 生成一个密钥对，保存在keyPair中
		KeyPair keyPair = keyPairGen.generateKeyPair();
		// 得到私钥
		RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
		// 得到公钥
		RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
		try {
			// 得到公钥字符串
			String publicKeyString = Base64.encode(publicKey.getEncoded());
			// 得到私钥字符串
			String privateKeyString = Base64.encode(privateKey.getEncoded());
			// 将密钥对写入到文件
			FileWriter pubfw = new FileWriter(filePath + "/publicKey.keystore");
			FileWriter prifw = new FileWriter(filePath + "/privateKey.keystore");
			BufferedWriter pubbw = new BufferedWriter(pubfw);
			BufferedWriter pribw = new BufferedWriter(prifw);
			pubbw.write(publicKeyString);
			pribw.write(privateKeyString);
			pubbw.flush();
			pubbw.close();
			pubfw.close();
			pribw.flush();
			pribw.close();
			prifw.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * 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 String loadPublicKeyByFile(String path) throws Exception {
		try {
			BufferedReader br = new BufferedReader(new FileReader(path
					+ "/publicKey.keystore"));
			String readLine = null;
			StringBuilder sb = new StringBuilder();
			while ((readLine = br.readLine()) != null) {
				sb.append(readLine);
			}
			br.close();
			return sb.toString();
		} 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 RSAPublicKey loadPublicKeyByStr(String publicKeyStr)
			throws Exception {
		try {
			byte[] buffer = Base64.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");
		}
	}

	/**
	 * 从文件中加载私钥
	 *
	 * @param keyFileName
	 *            私钥文件名
	 * @return 是否成功
	 * @throws Exception
	 */
	public static String loadPrivateKeyByFile(String path) throws Exception {
		try {
			BufferedReader br = new BufferedReader(new FileReader(path
					+ "/privateKey.keystore"));
			String readLine = null;
			StringBuilder sb = new StringBuilder();
			while ((readLine = br.readLine()) != null) {
				sb.append(readLine);
			}
			br.close();
			return sb.toString();
		} 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");
		}
	}

	public static RSAPrivateKey loadPrivateKeyByStr(String privateKeyStr)
			throws Exception {
		try {
			byte[] buffer = Base64.decode(privateKeyStr);
			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");
		}
	}

	/**
	 * 公钥加密过程
	 *
	 * @param publicKey
	 *            公钥
	 * @param plainTextData
	 *            明文数据
	 * @return
	 * @throws Exception
	 *             加密过程中的异常信息
	 */
	public static byte[] encrypt(RSAPublicKey publicKey, byte[] plainTextData)
			throws Exception {
		if (publicKey == null) {
			throw new Exception("加密公钥为空, 请设置");
		}
		Cipher cipher = null;
		try {
			// 使用默认RSA
			cipher = Cipher.getInstance("RSA");
			// cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
			cipher.init(Cipher.ENCRYPT_MODE, publicKey);
			byte[] output = cipher.doFinal(plainTextData);
			return output;
		} catch (NoSuchAlgorithmException e) {
			throw new Exception("无此加密算法");
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
			return null;
		} catch (InvalidKeyException e) {
			throw new Exception("加密公钥非法,请检查");
		} catch (IllegalBlockSizeException e) {
			throw new Exception("明文长度非法");
		} catch (BadPaddingException e) {
			throw new Exception("明文数据已损坏");
		}
	}

	/**
	 * 私钥加密过程
	 *
	 * @param privateKey
	 *            私钥
	 * @param plainTextData
	 *            明文数据
	 * @return
	 * @throws Exception
	 *             加密过程中的异常信息
	 */
	public static byte[] encrypt(RSAPrivateKey privateKey, byte[] plainTextData)
			throws Exception {
		if (privateKey == null) {
			throw new Exception("加密私钥为空, 请设置");
		}
		Cipher cipher = null;
		try {
			// 使用默认RSA
			cipher = Cipher.getInstance("RSA");
			cipher.init(Cipher.ENCRYPT_MODE, privateKey);
			byte[] output = cipher.doFinal(plainTextData);
			return output;
		} catch (NoSuchAlgorithmException e) {
			throw new Exception("无此加密算法");
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
			return null;
		} catch (InvalidKeyException e) {
			throw new Exception("加密私钥非法,请检查");
		} catch (IllegalBlockSizeException e) {
			throw new Exception("明文长度非法");
		} catch (BadPaddingException e) {
			throw new Exception("明文数据已损坏");
		}
	}

	/**
	 * 私钥解密过程
	 *
	 * @param privateKey
	 *            私钥
	 * @param cipherData
	 *            密文数据
	 * @return 明文
	 * @throws Exception
	 *             解密过程中的异常信息
	 */
	public static byte[] decrypt(RSAPrivateKey privateKey, byte[] cipherData)
			throws Exception {
		if (privateKey == null) {
			throw new Exception("解密私钥为空, 请设置");
		}
		Cipher cipher = null;
		try {
			// 使用默认RSA
			cipher = Cipher.getInstance("RSA");
			// cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
			cipher.init(Cipher.DECRYPT_MODE, privateKey);
			byte[] output = cipher.doFinal(cipherData);
			return output;
		} catch (NoSuchAlgorithmException e) {
			throw new Exception("无此解密算法");
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
			return null;
		} catch (InvalidKeyException e) {
			throw new Exception("解密私钥非法,请检查");
		} catch (IllegalBlockSizeException e) {
			throw new Exception("密文长度非法");
		} catch (BadPaddingException e) {
			throw new Exception("密文数据已损坏");
		}
	}

	/**
	 * 公钥解密过程
	 *
	 * @param publicKey
	 *            公钥
	 * @param cipherData
	 *            密文数据
	 * @return 明文
	 * @throws Exception
	 *             解密过程中的异常信息
	 */
	public static byte[] decrypt(RSAPublicKey publicKey, byte[] cipherData)
			throws Exception {
		if (publicKey == null) {
			throw new Exception("解密公钥为空, 请设置");
		}
		Cipher cipher = null;
		try {
			// 使用默认RSA
			cipher = Cipher.getInstance("RSA");
			// cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
			cipher.init(Cipher.DECRYPT_MODE, publicKey);
			byte[] output = cipher.doFinal(cipherData);
			return output;
		} catch (NoSuchAlgorithmException e) {
			throw new Exception("无此解密算法");
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
			return null;
		} catch (InvalidKeyException e) {
			throw new Exception("解密公钥非法,请检查");
		} catch (IllegalBlockSizeException e) {
			throw new Exception("密文长度非法");
		} catch (BadPaddingException e) {
			throw new Exception("密文数据已损坏");
		}
	}

	/**
	 * 字节数据转十六进制字符串
	 *
	 * @param data
	 *            输入数据
	 * @return 十六进制内容
	 */
	public static String byteArrayToString(byte[] data) {
		StringBuilder stringBuilder = new StringBuilder();
		for (int i = 0; i < data.length; i++) {
			// 取出字节的高四位 作为索引得到相应的十六进制标识符 注意无符号右移
			stringBuilder.append(HEX_CHAR[(data[i] & 0xf0) >>> 4]);
			// 取出字节的低四位 作为索引得到相应的十六进制标识符
			stringBuilder.append(HEX_CHAR[(data[i] & 0x0f)]);
			if (i < data.length - 1) {
				stringBuilder.append(‘ ‘);
			}
		}
		return stringBuilder.toString();
	}
}

签名及校验类：

package com.ihep;

import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

/**
 * RSA签名验签类
 */
public class RSASignature{

	/**
	 * 签名算法
	 */
	public static final String SIGN_ALGORITHMS = "SHA1WithRSA";

	/**
	* RSA签名
	* @param content 待签名数据
	* @param privateKey 商户私钥
	* @param encode 字符集编码
	* @return 签名值
	*/
	public static String sign(String content, String privateKey, String encode)
	{
        try
        {
        	PKCS8EncodedKeySpec priPKCS8 	= new PKCS8EncodedKeySpec( Base64.decode(privateKey) ); 

        	KeyFactory keyf 				= KeyFactory.getInstance("RSA");
        	PrivateKey priKey 				= keyf.generatePrivate(priPKCS8);

            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

            signature.initSign(priKey);
            signature.update( content.getBytes(encode));

            byte[] signed = signature.sign();

            return Base64.encode(signed);
        }
        catch (Exception e)
        {
        	e.printStackTrace();
        }

        return null;
    }

	public static String sign(String content, String privateKey)
	{
        try
        {
        	PKCS8EncodedKeySpec priPKCS8 	= new PKCS8EncodedKeySpec( Base64.decode(privateKey) );
        	KeyFactory keyf = KeyFactory.getInstance("RSA");
        	PrivateKey priKey = keyf.generatePrivate(priPKCS8);
            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);
            signature.initSign(priKey);
            signature.update( content.getBytes());
            byte[] signed = signature.sign();
            return Base64.encode(signed);
        }
        catch (Exception e)
        {
        	e.printStackTrace();
        }
        return null;
    }

	/**
	* RSA验签名检查
	* @param content 待签名数据
	* @param sign 签名值
	* @param publicKey 分配给开发商公钥
	* @param encode 字符集编码
	* @return 布尔值
	*/
	public static boolean doCheck(String content, String sign, String publicKey,String encode)
	{
		try
		{
			KeyFactory keyFactory = KeyFactory.getInstance("RSA");
	        byte[] encodedKey = Base64.decode(publicKey);
	        PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));

			java.security.Signature signature = java.security.Signature
			.getInstance(SIGN_ALGORITHMS);

			signature.initVerify(pubKey);
			signature.update( content.getBytes(encode) );

			boolean bverify = signature.verify( Base64.decode(sign) );
			return bverify;

		}
		catch (Exception e)
		{
			e.printStackTrace();
		}

		return false;
	}

	public static boolean doCheck(String content, String sign, String publicKey)
	{
		try
		{
			KeyFactory keyFactory = KeyFactory.getInstance("RSA");
	        byte[] encodedKey = Base64.decode(publicKey);
	        PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));

			java.security.Signature signature = java.security.Signature
			.getInstance(SIGN_ALGORITHMS);

			signature.initVerify(pubKey);
			signature.update( content.getBytes() );

			boolean bverify = signature.verify( Base64.decode(sign) );
			return bverify;

		}
		catch (Exception e)
		{
			e.printStackTrace();
		}

		return false;
	}

}

再来一个Base64的类，当然你也可以用commons-codec-1.9.jar

package com.ihep;

public final class Base64 {

    static private final int     BASELENGTH           = 128;
    static private final int     LOOKUPLENGTH         = 64;
    static private final int     TWENTYFOURBITGROUP   = 24;
    static private final int     EIGHTBIT             = 8;
    static private final int     SIXTEENBIT           = 16;
    static private final int     FOURBYTE             = 4;
    static private final int     SIGN                 = -128;
    static private final char    PAD                  = ‘=‘;
    static private final boolean fDebug               = false;
    static final private byte[]  base64Alphabet       = new byte[BASELENGTH];
    static final private char[]  lookUpBase64Alphabet = new char[LOOKUPLENGTH];

    static {
        for (int i = 0; i < BASELENGTH; ++i) {
            base64Alphabet[i] = -1;
        }
        for (int i = ‘Z‘; i >= ‘A‘; i--) {
            base64Alphabet[i] = (byte) (i - ‘A‘);
        }
        for (int i = ‘z‘; i >= ‘a‘; i--) {
            base64Alphabet[i] = (byte) (i - ‘a‘ + 26);
        }

        for (int i = ‘9‘; i >= ‘0‘; i--) {
            base64Alphabet[i] = (byte) (i - ‘0‘ + 52);
        }

        base64Alphabet[‘+‘] = 62;
        base64Alphabet[‘/‘] = 63;

        for (int i = 0; i <= 25; i++) {
            lookUpBase64Alphabet[i] = (char) (‘A‘ + i);
        }

        for (int i = 26, j = 0; i <= 51; i++, j++) {
            lookUpBase64Alphabet[i] = (char) (‘a‘ + j);
        }

        for (int i = 52, j = 0; i <= 61; i++, j++) {
            lookUpBase64Alphabet[i] = (char) (‘0‘ + j);
        }
        lookUpBase64Alphabet[62] = (char) ‘+‘;
        lookUpBase64Alphabet[63] = (char) ‘/‘;

    }

    private static boolean isWhiteSpace(char octect) {
        return (octect == 0x20 || octect == 0xd || octect == 0xa || octect == 0x9);
    }

    private static boolean isPad(char octect) {
        return (octect == PAD);
    }

    private static boolean isData(char octect) {
        return (octect < BASELENGTH && base64Alphabet[octect] != -1);
    }

    /**
     * Encodes hex octects into Base64
     *
     * @param binaryData Array containing binaryData
     * @return Encoded Base64 array
     */
    public static String encode(byte[] binaryData) {

        if (binaryData == null) {
            return null;
        }

        int lengthDataBits = binaryData.length * EIGHTBIT;
        if (lengthDataBits == 0) {
            return "";
        }

        int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;
        int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;
        int numberQuartet = fewerThan24bits != 0 ? numberTriplets + 1 : numberTriplets;
        char encodedData[] = null;

        encodedData = new char[numberQuartet * 4];

        byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;

        int encodedIndex = 0;
        int dataIndex = 0;
        if (fDebug) {
            System.out.println("number of triplets = " + numberTriplets);
        }

        for (int i = 0; i < numberTriplets; i++) {
            b1 = binaryData[dataIndex++];
            b2 = binaryData[dataIndex++];
            b3 = binaryData[dataIndex++];

            if (fDebug) {
                System.out.println("b1= " + b1 + ", b2= " + b2 + ", b3= " + b3);
            }

            l = (byte) (b2 & 0x0f);
            k = (byte) (b1 & 0x03);

            byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
            byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
            byte val3 = ((b3 & SIGN) == 0) ? (byte) (b3 >> 6) : (byte) ((b3) >> 6 ^ 0xfc);

            if (fDebug) {
                System.out.println("val2 = " + val2);
                System.out.println("k4   = " + (k << 4));
                System.out.println("vak  = " + (val2 | (k << 4)));
            }

            encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];
            encodedData[encodedIndex++] = lookUpBase64Alphabet[val2 | (k << 4)];
            encodedData[encodedIndex++] = lookUpBase64Alphabet[(l << 2) | val3];
            encodedData[encodedIndex++] = lookUpBase64Alphabet[b3 & 0x3f];
        }

        // form integral number of 6-bit groups
        if (fewerThan24bits == EIGHTBIT) {
            b1 = binaryData[dataIndex];
            k = (byte) (b1 & 0x03);
            if (fDebug) {
                System.out.println("b1=" + b1);
                System.out.println("b1<<2 = " + (b1 >> 2));
            }
            byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
            encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];
            encodedData[encodedIndex++] = lookUpBase64Alphabet[k << 4];
            encodedData[encodedIndex++] = PAD;
            encodedData[encodedIndex++] = PAD;
        } else if (fewerThan24bits == SIXTEENBIT) {
            b1 = binaryData[dataIndex];
            b2 = binaryData[dataIndex + 1];
            l = (byte) (b2 & 0x0f);
            k = (byte) (b1 & 0x03);

            byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
            byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);

            encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];
            encodedData[encodedIndex++] = lookUpBase64Alphabet[val2 | (k << 4)];
            encodedData[encodedIndex++] = lookUpBase64Alphabet[l << 2];
            encodedData[encodedIndex++] = PAD;
        }

        return new String(encodedData);
    }

    /**
     * Decodes Base64 data into octects
     *
     * @param encoded string containing Base64 data
     * @return Array containind decoded data.
     */
    public static byte[] decode(String encoded) {

        if (encoded == null) {
            return null;
        }

        char[] base64Data = encoded.toCharArray();
        // remove white spaces
        int len = removeWhiteSpace(base64Data);

        if (len % FOURBYTE != 0) {
            return null;//should be divisible by four
        }

        int numberQuadruple = (len / FOURBYTE);

        if (numberQuadruple == 0) {
            return new byte[0];
        }

        byte decodedData[] = null;
        byte b1 = 0, b2 = 0, b3 = 0, b4 = 0;
        char d1 = 0, d2 = 0, d3 = 0, d4 = 0;

        int i = 0;
        int encodedIndex = 0;
        int dataIndex = 0;
        decodedData = new byte[(numberQuadruple) * 3];

        for (; i < numberQuadruple - 1; i++) {

            if (!isData((d1 = base64Data[dataIndex++])) || !isData((d2 = base64Data[dataIndex++]))
                || !isData((d3 = base64Data[dataIndex++]))
                || !isData((d4 = base64Data[dataIndex++]))) {
                return null;
            }//if found "no data" just return null

            b1 = base64Alphabet[d1];
            b2 = base64Alphabet[d2];
            b3 = base64Alphabet[d3];
            b4 = base64Alphabet[d4];

            decodedData[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);
            decodedData[encodedIndex++] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
            decodedData[encodedIndex++] = (byte) (b3 << 6 | b4);
        }

        if (!isData((d1 = base64Data[dataIndex++])) || !isData((d2 = base64Data[dataIndex++]))) {
            return null;//if found "no data" just return null
        }

        b1 = base64Alphabet[d1];
        b2 = base64Alphabet[d2];

        d3 = base64Data[dataIndex++];
        d4 = base64Data[dataIndex++];
        if (!isData((d3)) || !isData((d4))) {//Check if they are PAD characters
            if (isPad(d3) && isPad(d4)) {
                if ((b2 & 0xf) != 0)//last 4 bits should be zero
                {
                    return null;
                }
                byte[] tmp = new byte[i * 3 + 1];
                System.arraycopy(decodedData, 0, tmp, 0, i * 3);
                tmp[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
                return tmp;
            } else if (!isPad(d3) && isPad(d4)) {
                b3 = base64Alphabet[d3];
                if ((b3 & 0x3) != 0)//last 2 bits should be zero
                {
                    return null;
                }
                byte[] tmp = new byte[i * 3 + 2];
                System.arraycopy(decodedData, 0, tmp, 0, i * 3);
                tmp[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);
                tmp[encodedIndex] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
                return tmp;
            } else {
                return null;
            }
        } else { //No PAD e.g 3cQl
            b3 = base64Alphabet[d3];
            b4 = base64Alphabet[d4];
            decodedData[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);
            decodedData[encodedIndex++] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
            decodedData[encodedIndex++] = (byte) (b3 << 6 | b4);

        }

        return decodedData;
    }

    /**
     * remove WhiteSpace from MIME containing encoded Base64 data.
     *
     * @param data  the byte array of base64 data (with WS)
     * @return      the new length
     */
    private static int removeWhiteSpace(char[] data) {
        if (data == null) {
            return 0;
        }

        // count characters that‘s not whitespace
        int newSize = 0;
        int len = data.length;
        for (int i = 0; i < len; i++) {
            if (!isWhiteSpace(data[i])) {
                data[newSize++] = data[i];
            }
        }
        return newSize;
    }
}

最后是一个MainTest：

package com.ihep;

public class MainTest {

	public static void main(String[] args) throws Exception {
		String filepath="G:/tmp/";

		//RSAEncrypt.genKeyPair(filepath);

		System.out.println("--------------公钥加密私钥解密过程-------------------");
		String plainText="ihep_公钥加密私钥解密";
		//公钥加密过程
		byte[] cipherData=RSAEncrypt.encrypt(RSAEncrypt.loadPublicKeyByStr(RSAEncrypt.loadPublicKeyByFile(filepath)),plainText.getBytes());
		String cipher=Base64.encode(cipherData);
		//私钥解密过程
		byte[] res=RSAEncrypt.decrypt(RSAEncrypt.loadPrivateKeyByStr(RSAEncrypt.loadPrivateKeyByFile(filepath)), Base64.decode(cipher));
		String restr=new String(res);
		System.out.println("原文："+plainText);
		System.out.println("加密："+cipher);
		System.out.println("解密："+restr);
		System.out.println();

		System.out.println("--------------私钥加密公钥解密过程-------------------");
		plainText="ihep_私钥加密公钥解密";
		//私钥加密过程
		cipherData=RSAEncrypt.encrypt(RSAEncrypt.loadPrivateKeyByStr(RSAEncrypt.loadPrivateKeyByFile(filepath)),plainText.getBytes());
		cipher=Base64.encode(cipherData);
		//公钥解密过程
		res=RSAEncrypt.decrypt(RSAEncrypt.loadPublicKeyByStr(RSAEncrypt.loadPublicKeyByFile(filepath)), Base64.decode(cipher));
		restr=new String(res);
		System.out.println("原文："+plainText);
		System.out.println("加密："+cipher);
		System.out.println("解密："+restr);
		System.out.println();

		System.out.println("---------------私钥签名过程------------------");
		String content="ihep_这是用于签名的原始数据";
		String signstr=RSASignature.sign(content,RSAEncrypt.loadPrivateKeyByFile(filepath));
		System.out.println("签名原串："+content);
		System.out.println("签名串："+signstr);
		System.out.println();

		System.out.println("---------------公钥校验签名------------------");
		System.out.println("签名原串："+content);
		System.out.println("签名串："+signstr);

		System.out.println("验签结果："+RSASignature.doCheck(content, signstr, RSAEncrypt.loadPublicKeyByFile(filepath)));
		System.out.println();

	}
}

看看运行截图：

转载请注明：http://blog.csdn.net/wangqiuyun/article/details/42143957