這裏的base64的依賴不一樣，一個是apache,一個是sun的 ,由於base64的依賴不同，導致在IOS中解析不了！

package com.handsight.platform.cipher;

import java.io.ByteArrayOutputStream;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
 
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;

 
import javax.crypto.Cipher;

import sun.misc.BASE64Decoder;                 //據說是sun公司未發布jar
import sun.misc.BASE64Encoder;

public class CreateSecretKey {

    public static final String KEY_ALGORITHM = "RSA";
    private static final String PUBLIC_KEY = "RSAPublicKey";
    private static final
 
 String PRIVATE_KEY = "RSAPrivateKey";
    public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
    /**
     * * RSA最大加密明文大小
     */

    private static final int MAX_ENCRYPT_BLOCK = 117;
    /**
     * * RSA最大解密密文大小
     */

    private static final int MAX_DECRYPT_BLOCK = 128; // 獲得公鑰字符串

    public static String getPublicKeyStr(Map<String, Object> keyMap) throws Exception {
        // 獲得map中的公鑰對象 轉為key對象
        Key key = (Key) keyMap.get(PUBLIC_KEY);
        // 編碼返回字符串
        return encryptBASE64(key.getEncoded());
    }

    // 獲得私鑰字符串

    public static String getPrivateKeyStr(Map<String, Object> keyMap) throws Exception {
        // 獲得map中的私鑰對象 轉為key對象
        Key key = (Key) keyMap.get(PRIVATE_KEY);
        // 編碼返回字符串
        return encryptBASE64(key.getEncoded());
    } // 獲取公鑰

    public static PublicKey getPublicKey(String key) throws Exception {
        byte[] keyBytes;
        keyBytes = (new BASE64Decoder()).decodeBuffer(key);
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        PublicKey publicKey = keyFactory.generatePublic(keySpec);
        return publicKey;
    } // 獲取私鑰

    public static PrivateKey getPrivateKey(String key) throws Exception {
        byte[] keyBytes;
        keyBytes = (new BASE64Decoder()).decodeBuffer(key);
        PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        PrivateKey privateKey = keyFactory.generatePrivate(keySpec);
        return privateKey;
    } // 解碼返回byte

    public static byte[] decryptBASE64(String key) throws Exception {
        return (new BASE64Decoder()).decodeBuffer(key);
    }

    // 編碼返回字符串

    public static String encryptBASE64(byte[] key) throws Exception {
        return (new BASE64Encoder()).encodeBuffer(key);
    } // ***************************簽名和驗證*******************************

    public static byte[] sign(byte[] data, String privateKeyStr) throws Exception {
        PrivateKey priK = getPrivateKey(privateKeyStr);
        Signature sig = Signature.getInstance(SIGNATURE_ALGORITHM);
        sig.initSign(priK);
        sig.update(data);
        return sig.sign();
    }

    public static boolean verify(byte[] data, byte[] sign, String publicKeyStr) throws Exception {
        PublicKey pubK = getPublicKey(publicKeyStr);
        Signature sig = Signature.getInstance(SIGNATURE_ALGORITHM);
        sig.initVerify(pubK);
        sig.update(data);
        return sig.verify(sign);
    } // ************************加密解密**************************

    public static byte[] encrypt(byte[] plainText, String publicKeyStr) throws Exception {
        PublicKey publicKey = getPublicKey(publicKeyStr);
        Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        int inputLen = plainText.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        int i = 0;
        byte[] cache;
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(plainText, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(plainText, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptText = out.toByteArray();
        out.close();
        return encryptText;
    }

    public static byte[] decrypt(byte[] encryptText, String privateKeyStr) throws Exception {
        PrivateKey privateKey = getPrivateKey(privateKeyStr);
        Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        int inputLen = encryptText.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 對數據分段解密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                cache = cipher.doFinal(encryptText, offSet, MAX_DECRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(encryptText, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_DECRYPT_BLOCK;
        }
        byte[] plainText = out.toByteArray();
        out.close();
        return plainText;
    }

    public static void main(String[] args) {
        Map<String, Object> keyMap;
        byte[] cipherText;
        String input = "Hello World!";
        try {
            keyMap = initKey();
            String publicKey = getPublicKeyStr(keyMap);
            System.out.println("公鑰------------------");
            System.out.println(publicKey);
            String privateKey = getPrivateKeyStr(keyMap);
            System.out.println("私鑰------------------");
            System.out.println(privateKey);

            System.out.println("測試可行性-------------------");
            System.out.println("明文=======" + input);

            cipherText = encrypt(input.getBytes(), publicKey);
            // 加密後的東西 
            System.out.println("密文=======" + new String(cipherText));
            // 開始解密 
            byte[] plainText = decrypt(cipherText, privateKey);
            System.out.println("解密後明文===== " + new String(plainText));
            System.out.println("驗證簽名-----------");
            String str = "被簽名的內容";
            System.out.println("\n原文:" + str);
            byte[] signature = sign(str.getBytes(), privateKey);
            boolean status = verify(str.getBytes(), signature, publicKey);
            System.out.println("驗證情況：" + status);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static Map<String, Object> initKey() throws Exception {
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
        keyPairGen.initialize(1024);
        KeyPair keyPair = keyPairGen.generateKeyPair();
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
        Map<String, Object> keyMap = new HashMap<String, Object>(2);
        keyMap.put(PUBLIC_KEY, publicKey);
        keyMap.put(PRIVATE_KEY, privateKey);
        return keyMap;
    }
}

測試：

package com.handsight.platform.cipher;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.math.BigInteger;
import java.security.GeneralSecurityException;
import java.security.Key;
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.RSAPrivateKeySpec;
import java.security.spec.RSAPublicKeySpec;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class TestRSA {
    // RSA算法對文件加密
    public void encryptByRSA(String fileName, String saveFileName, String keyFileName) throws Exception {
        long start = System.currentTimeMillis();
        try {
            KeyGenerator keygen = KeyGenerator.getInstance("AES");
            SecureRandom random = new SecureRandom();
            keygen.init(random);
            SecretKey key = keygen.generateKey();
            String[] result = readKeyUtil(new File(keyFileName));
            RSAPublicKey key2 = getPublicKey(result[0], result[1]);
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.WRAP_MODE, key2);
            byte[] wrappedKey = cipher.wrap(key);
            DataOutputStream out = new DataOutputStream(new FileOutputStream(saveFileName));
            out.writeInt(wrappedKey.length);
            out.write(wrappedKey);
            InputStream in = new FileInputStream(fileName);
            cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.ENCRYPT_MODE, key);
            crypt(in, out, cipher);
            in.close();
            out.close();
        } catch (GeneralSecurityException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        long end = System.currentTimeMillis();
        System.out.println("總共耗時：" + (end - start));
    }

    // RSA算法對文件解密
    public void decryptByRSA(String fileName, String saveFileName, String keyFileName) throws Exception {
        try {
            DataInputStream in = new DataInputStream(new FileInputStream(fileName));
            int length = in.readInt();
            byte[] wrappedKey = new byte[length];
            in.read(wrappedKey, 0, length);
            String[] result = readKeyUtil(new File(keyFileName));
            RSAPrivateKey key2 = getPrivateKey(result[0], result[1]);

            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.UNWRAP_MODE, key2);
            Key key = cipher.unwrap(wrappedKey, "AES", Cipher.SECRET_KEY);

            OutputStream out = new FileOutputStream(saveFileName);
            cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.DECRYPT_MODE, key);

            crypt(in, out, cipher);
            in.close();
            out.close();
        } catch (GeneralSecurityException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    //對數據塊加密
    public void crypt(InputStream in, OutputStream out, Cipher cipher) throws IOException, GeneralSecurityException {
        int blockSize = cipher.getBlockSize();
        int outputSize = cipher.getOutputSize(blockSize);
        byte[] inBytes = new byte[blockSize];
        byte[] outBytes = new byte[outputSize];

        int inLength = 0;
        boolean next = true;
        while (next) {
            inLength = in.read(inBytes);
            System.out.println(inLength);
            if (inLength == blockSize) {
                int outLength = cipher.update(inBytes, 0, blockSize, outBytes);
                out.write(outBytes, 0, outLength);
            } else {
                next = false;
            }
        }
        if (inLength > 0) {
            outBytes = cipher.doFinal(inBytes, 0, inLength);
        } else {
            outBytes = cipher.doFinal();
        }
        out.write(outBytes);
    }

    //生成RSA密鑰對
    public void generateRSAKey(String savePath) throws Exception {
        try {
            KeyPairGenerator keygen = KeyPairGenerator.getInstance("RSA");
            SecureRandom random = new SecureRandom();
            keygen.initialize(RSA_KEYSIZE, random);
            KeyPair keyPair = keygen.generateKeyPair();
            RSAPublicKey puk = (RSAPublicKey) keyPair.getPublic();
            createXmlFile(puk.getModulus().toString(), puk.getPublicExponent().toString(), savePath + "\\public.xml");
            RSAPrivateKey prk = (RSAPrivateKey) keyPair.getPrivate();
            createXmlFile(prk.getModulus().toString(), prk.getPrivateExponent().toString(), savePath + "\\private.xml");
            /*
             * OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream(savePath
             * + "\\public.xml")); // 得到公鑰字符串 System.out.println(puk.getModulus());
             * System.out.println(puk.getPublicExponent());
             * System.out.println(prk.getModulus());
             * System.out.println(prk.getPrivateExponent()); // 得到私鑰字符串
             * osw.write(createXmlFile(puk.getModulus().toString(),
             * puk.getPublicExponent().toString())); osw.close(); osw = new
             * OutputStreamWriter(new FileOutputStream(savePath + "\\private.xml"));
             * osw.write(createXmlFile(prk.getModulus().toString(),
             * prk.getPrivateExponent().toString())); osw.close();
             */
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
    }

    /**
     * 使用模和指數生成RSA公鑰
     * 註意：【此代碼用了默認補位方式，為RSA/None/PKCS1Padding，不同JDK默認的補位方式可能不同，如Android默認是RSA
     * /None/NoPadding】
     *
     * @param modulus  模
     * @param exponent 指數
     * @return
     */
    public static RSAPublicKey getPublicKey(String modulus, String exponent) {
        try {
            BigInteger b1 = new BigInteger(modulus);
            BigInteger b2 = new BigInteger(exponent);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            RSAPublicKeySpec keySpec = new RSAPublicKeySpec(b1, b2);
            return (RSAPublicKey) keyFactory.generatePublic(keySpec);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 使用模和指數生成RSA私鑰
     * 註意：【此代碼用了默認補位方式，為RSA/None/PKCS1Padding，不同JDK默認的補位方式可能不同，如Android默認是RSA
     * /None/NoPadding】
     *
     * @param modulus  模
     * @param exponent 指數
     * @return
     */
    public static RSAPrivateKey getPrivateKey(String modulus, String exponent) {
        try {
            BigInteger b1 = new BigInteger(modulus);
            BigInteger b2 = new BigInteger(exponent);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            RSAPrivateKeySpec keySpec = new RSAPrivateKeySpec(b1, b2);
            return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 生成xml字符串
     *
     * @return
     * @throws Exception
     */
    public static void createXmlFile(String Modulus, String Exponent, String filepath) throws Exception {
        Document document = DocumentHelper.createDocument();
        Element root = document.addElement("root");
        Element supercarElement = root.addElement("Modulus");

        supercarElement.addText(Modulus);
        Element supercarElement2 = root.addElement("Exponent");

        supercarElement2.addText(Exponent);
        // 寫入到一個新的文件中
        writer(document, filepath);
    }

    /**
     * 把document對象寫入新的文件
     *
     * @param document
     * @throws Exception
     */
    public static void writer(Document document, String path) throws Exception {
        // 緊湊的格式
        // 排版縮進的格式
        OutputFormat format = OutputFormat.createPrettyPrint();
        // 設置編碼
        format.setEncoding("UTF-8");
        // 創建XMLWriter對象,指定了寫出文件及編碼格式
        XMLWriter writer = new XMLWriter(new OutputStreamWriter(new FileOutputStream(new File(path)), "UTF-8"), format);
        // 寫入
        writer.write(document);
        // 立即寫入
        writer.flush();
        // 關閉操作
        writer.close();
    }

    public String[] readKeyUtil(File file) throws DocumentException {
        // 創建saxReader對象
        SAXReader reader = new SAXReader();
        // 通過read方法讀取一個文件 轉換成Document對象
        Document document = reader.read(file);
        // 獲取根節點元素對象
        Element node = document.getRootElement();
        Element ele = node.element("Modulus");
        String Modulus = ele.getTextTrim();
        Element ele1 = node.element("Exponent");
        String Exponent = ele1.getTextTrim();
        return new String[] { Modulus, Exponent };
    }

    private static final int RSA_KEYSIZE = 1024;

    public static void main(String[] args) throws Exception {
        String path ="E:/home/handsight/aic/";
        // 生成xml格式的公鑰和私鑰
        new TestRSA().generateRSAKey(path);
        // 對文件進行加密
        new TestRSA().encryptByRSA(path + "/12345.txt", path + "/456.txt", path + "/public.xml");
        // 對文件進行解密
        new TestRSA().decryptByRSA(path + "/456.txt", path + "/12345_new.txt", path + "/private.xml");
    }
}

RSA加密的java實現2(交互IOS)