Android 获取签名公钥 和 公钥私钥加解密

public class GetPublicKey {         /**     * 获取签名公钥     * @param mContext     * @return     */    protected static String getSignInfo(Context mContext) {        String signcode = "";        try {            PackageInfo packageInfo = mContext.getPackageManager().getPackageInfo(                    GetAppInfo.getPackageName(mContext), PackageManager.GET_SIGNATURES);            Signature[] signs = packageInfo.signatures;            Signature sign = signs[0];             signcode = parseSignature(sign.toByteArray());            signcode = signcode.toLowerCase();        } catch (Exception e) {            Log.e(Constants.TAG, e.getMessage(), e);        }        return signcode;    }     protected static String parseSignature(byte[] signature) {        String sign = "";        try {            CertificateFactory certFactory = CertificateFactory                    .getInstance("X.509");            X509Certificate cert = (X509Certificate) certFactory                    .generateCertificate(new ByteArrayInputStream(signature));            String pubKey = cert.getPublicKey().toString();            String ss = subString(pubKey);            ss = ss.replace(",", "");            ss = ss.toLowerCase();            int aa = ss.indexOf("modulus");            int bb = ss.indexOf("publicexponent");            sign = ss.substring(aa + 8, bb);        } catch (CertificateException e) {            Log.e(Constants.TAG, e.getMessage(), e);        }        return sign;    }     public static String subString(String sub) {        Pattern pp = Pattern.compile("\\s*|\t|\r|\n");        Matcher mm = pp.matcher(sub);        return mm.replaceAll("");    }}

package com.example.xscamera; 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; /** * <p> * RSA公钥/私钥/签名工具包 * <p> * 字符串格式的密钥在未在特殊说明情况下都为BASE64编码格式<br/> * 由于非对称加密速度极其缓慢，一般文件不使用它来加密而是使用对称加密，<br/> * 非对称加密算法可以用来对对称加密的密钥加密，这样保证密钥的安全也就保证了数据的安全 * </p> *  */public class RSAUtils{     /**     * 加密算法RSA     */    public static final String KEY_ALGORITHM = "RSA";         /**     * 签名算法     */    public static final String SIGNATURE_ALGORITHM = "MD5withRSA";     /**     * 获取公钥的key     */    private static final String PUBLIC_KEY = "LocatorPublicKey";         /**     * 获取私钥的key     */    private static final String PRIVATE_KEY = "LocatorPrivateKey";         /**     * 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;     /**     * <p>     * 生成密钥对(公钥和私钥)     * </p>     *      * @return     * @throws Exception     */    public static Map<String, Object> genKeyPair() 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;    }         /**     * <p>     * 用私钥对信息生成数字签名     * </p>     *      * @param data 已加密数据     * @param privateKey 私钥(BASE64编码)     *      * @return     * @throws Exception     */    public static String sign(byte[] data, String privateKey) throws Exception {        byte[] keyBytes = Base64Utils.decode(privateKey);        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);        PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);        signature.initSign(privateK);        signature.update(data);        return Base64Utils.encode(signature.sign());    }     /**     * <p>     * 校验数字签名     * </p>     *      * @param data 已加密数据     * @param publicKey 公钥(BASE64编码)     * @param sign 数字签名     *      * @return     * @throws Exception     *      */    public static boolean verify(byte[] data, String publicKey, String sign)            throws Exception {        byte[] keyBytes = Base64Utils.decode(publicKey);        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);        PublicKey publicK = keyFactory.generatePublic(keySpec);        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);        signature.initVerify(publicK);        signature.update(data);        return signature.verify(Base64Utils.decode(sign));    }     /**     * <P>     * 私钥解密     * </p>     *      * @param encryptedData 已加密数据     * @param privateKey 私钥(BASE64编码)     * @return     * @throws Exception     */    public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey)            throws Exception {        byte[] keyBytes = Base64Utils.decode(privateKey);        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());        cipher.init(Cipher.DECRYPT_MODE, privateK);        int inputLen = encryptedData.length;        ByteArrayOutputStream out = new ByteArrayOutputStream();        int offSet = 0;        byte[] cache;        int i = 0;        // 对数据分段解密        while (inputLen - offSet > 0) {            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);            } else {                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);            }            out.write(cache, 0, cache.length);            i++;            offSet = i * MAX_DECRYPT_BLOCK;        }        byte[] decryptedData = out.toByteArray();        out.close();        return decryptedData;    }     /**     * <p>     * 公钥解密     * </p>     *      * @param encryptedData 已加密数据     * @param publicKey 公钥(BASE64编码)     * @return     * @throws Exception     */    public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey)            throws Exception {        byte[] keyBytes = Base64Utils.decode(publicKey);        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);        Key publicK = keyFactory.generatePublic(x509KeySpec);        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());        cipher.init(Cipher.DECRYPT_MODE, publicK);        int inputLen = encryptedData.length;        ByteArrayOutputStream out = new ByteArrayOutputStream();        int offSet = 0;        byte[] cache;        int i = 0;        // 对数据分段解密        while (inputLen - offSet > 0) {            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);            } else {                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);            }            out.write(cache, 0, cache.length);            i++;            offSet = i * MAX_DECRYPT_BLOCK;        }        byte[] decryptedData = out.toByteArray();        out.close();        return decryptedData;    }     /**     * <p>     * 公钥加密     * </p>     *      * @param data 源数据     * @param publicKey 公钥(BASE64编码)     * @return     * @throws Exception     */    public static byte[] encryptByPublicKey(byte[] data, String publicKey)            throws Exception {        byte[] keyBytes = Base64Utils.decode(publicKey);        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);        Key publicK = keyFactory.generatePublic(x509KeySpec);        // 对数据加密        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());        cipher.init(Cipher.ENCRYPT_MODE, publicK);        int inputLen = data.length;        ByteArrayOutputStream out = new ByteArrayOutputStream();        int offSet = 0;        byte[] cache;        int i = 0;        // 对数据分段加密        while (inputLen - offSet > 0) {            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);            } else {                cache = cipher.doFinal(data, offSet, inputLen - offSet);            }            out.write(cache, 0, cache.length);            i++;            offSet = i * MAX_ENCRYPT_BLOCK;        }        byte[] encryptedData = out.toByteArray();        out.close();        return encryptedData;    }     /**     * <p>     * 私钥加密     * </p>     *      * @param data 源数据     * @param privateKey 私钥(BASE64编码)     * @return     * @throws Exception     */    public static byte[] encryptByPrivateKey(byte[] data, String privateKey)            throws Exception {        byte[] keyBytes = Base64Utils.decode(privateKey);        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());        cipher.init(Cipher.ENCRYPT_MODE, privateK);        int inputLen = data.length;        ByteArrayOutputStream out = new ByteArrayOutputStream();        int offSet = 0;        byte[] cache;        int i = 0;        // 对数据分段加密        while (inputLen - offSet > 0) {            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);            } else {                cache = cipher.doFinal(data, offSet, inputLen - offSet);            }            out.write(cache, 0, cache.length);            i++;            offSet = i * MAX_ENCRYPT_BLOCK;        }        byte[] encryptedData = out.toByteArray();        out.close();        return encryptedData;    }     /**     * <p>     * 获取私钥     * </p>     *      * @param keyMap 密钥对     * @return     * @throws Exception     */    public static String getPrivateKey(Map<String, Object> keyMap)            throws Exception {        Key key = (Key) keyMap.get(PRIVATE_KEY);        return Base64Utils.encode(key.getEncoded());    }     /**     * <p>     * 获取公钥     * </p>     *      * @param keyMap 密钥对     * @return     * @throws Exception     */    public static String getPublicKey(Map<String, Object> keyMap)            throws Exception {        Key key = (Key) keyMap.get(PUBLIC_KEY);        return Base64Utils.encode(key.getEncoded());    } }