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Android-rsa解密服务端给的加密过的内容,利用rsa公钥

Android-rsa解密服务端给的加密过的内容,利用rsa公钥

作者: MonkeyLei | 来源:发表于2020-01-16 13:06 被阅读0次

    内容后台加密方式:Base64 encode加密 -> Rsa私钥加密, 给我公钥用来解密, 实现方式参考:PHP实现RSA加解密

    前端界面方式:Base64 *decode解密->Rsa公钥解密, 参考 *Android数据加密之Rsa加密 - 总李写代码 - 博客园 CSDN-专业IT技术社区-登录 Android加密算法-我参考这个修改完善了了之前其他资料的公钥分块解密。。

    最后从调用方式提供工具类:- 如果你的遇到一些问题,比较后台加密方式不同,你需要查阅资料修改一些获取公钥的一些参数,有时候也会有错误提示。我没具体研究加密,就没有怎么深入。。。。喵...

    RsaDataUtil.java - 注意这个方法CryptorNatvie.getPubliscKey(MyApplication.getInstance())/GlobalAppInfo.public_key/)是我获取本地so里面的一个rsa公钥的方式。你可以直接替换为自己的公钥字符串。

        /**
    *@Author: hl
    *@Date: created at 2019/12/25 11:43
    *@Description: 获取RAS加密内容工具
    */
    public class RsaDataUtil {
    
        /**
         * 解密RAS字符串
         * @param originStr
         * @return
         */
        public static String getContentByRSA(String originStr) {
            try {
                byte[] bytes = RSAUtil.decryptWithPublicKeyBlock(
                        Base64Util.decodeToBytes(originStr),
                        CryptorNatvie.getPubliscKey(MyApplication.getInstance())/*GlobalAppInfo.public_key*/);
                return new String(bytes, "UTF-8");
            } catch (Exception e) {
                e.printStackTrace();
            }
            return "";
        }
    }
    

    RSAUtil.java - 具体的Rsa加密解密方式,我这里重点关注decryptWithPublicKeyBlock

    import java.io.BufferedReader;
    import java.io.ByteArrayOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.math.BigInteger;
    import java.security.Key;
    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: hl
     * @Date: created at 2019/12/25 11:02
     * @Description: RSA加密解密工具
     */
    public class RSAUtil {
        /**
         * 某些时候,后台(目前php后台)给的公钥并不支持RSA/ECB/PKCS1Padding算法,所以我们只需要RSA算法来通过公钥获取解密的key
         * 因此:分开两个变量使用
         */
        private static String ECB_PADDING = "RSA/ECB/PKCS1Padding";
        private static String RSA = "RSA";
    
        /**
         * RSA算法规定:待加密的字节数不能超过密钥的长度值除以8再减去11。
         * 而加密后得到密文的字节数,正好是密钥的长度值除以 8。
         */
        private static int KEYSIZE = 2048;// 密钥位数
        private static int RESERVE_BYTES = 11;
        private static int DECRYPT_BLOCK = KEYSIZE / 8;
        private static int ENCRYPT_BLOCK = DECRYPT_BLOCK - RESERVE_BYTES;
    
        /**
         * 随机生成RSA密钥对范围:512~2048
         * (默认密钥长度为1024)
         */
        public static KeyPair generateRSAKeyPair() {
            return generateRSAKeyPair(1024);
        }
    
        /**
         * 随机生成RSA密钥对
         */
        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
         */
        public static byte[] encryptDataPublic(byte[] data, PublicKey publicKey) {
    
            try {
                // 对数据加密
                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;
            }
        }
    
        /**
         * 用公钥解密 - 传PublicKey的方式
         */
        public static byte[] decryptDataPublic(byte[] data, PublicKey publicKey) {
    
            try {
                // 对数据解密
                Cipher cipher = Cipher.getInstance(RSA);
                cipher.init(Cipher.DECRYPT_MODE, publicKey);
                return cipher.doFinal(data);
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    
        /**
         * 分块公钥加密
         *
         * @param data
         * @param key
         */
        public static byte[] encryptWithPublicKeyBlock(byte[] data, byte[] key) throws Exception {
            int blockCount = (data.length / ENCRYPT_BLOCK);
    
            if ((data.length % ENCRYPT_BLOCK) != 0) {
                blockCount += 1;
            }
    
            ByteArrayOutputStream bos = new ByteArrayOutputStream(blockCount * ENCRYPT_BLOCK);
            Cipher cipher = Cipher.getInstance(ECB_PADDING);
            cipher.init(Cipher.ENCRYPT_MODE, getPublicKey(key));
    
            for (int offset = 0; offset < data.length; offset += ENCRYPT_BLOCK) {
                int inputLen = (data.length - offset);
                if (inputLen > ENCRYPT_BLOCK) {
                    inputLen = ENCRYPT_BLOCK;
                }
                byte[] encryptedBlock = cipher.doFinal(data, offset, inputLen);
                bos.write(encryptedBlock);
            }
    
            bos.close();
            return bos.toByteArray();
        }
    
        /**
         * 用公钥解密 - 传字符串的方式
         * ECB_PADDING--当前我的php后台数据加密方式
         */
        public static byte[] decryptDataPublic(byte[] data, String _publicKey) {
    
            try {
                PublicKey publicKey = loadPublicKey(_publicKey);
                // 对数据解密
                Cipher cipher = Cipher.getInstance(ECB_PADDING);
                cipher.init(Cipher.DECRYPT_MODE, publicKey);
                byte[] resultBytes = cipher.doFinal(data);
                return resultBytes;
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }
    
        /**
         * 分块公钥解密
         *
         * @param data
         * @param key
         */
        public static byte[] decryptWithPublicKeyBlock(byte[] data, byte[] key) throws Exception {
            int blockCount = (data.length / DECRYPT_BLOCK);
            if ((data.length % DECRYPT_BLOCK) != 0) {
                blockCount += 1;
            }
            ByteArrayOutputStream bos = new ByteArrayOutputStream(blockCount * DECRYPT_BLOCK);
            Cipher cipher = Cipher.getInstance(ECB_PADDING);
            cipher.init(Cipher.DECRYPT_MODE, getPublicKey(key));
            for (int offset = 0; offset < data.length; offset += DECRYPT_BLOCK) {
                int inputLen = (data.length - offset);
                if (inputLen > DECRYPT_BLOCK) {
                    inputLen = DECRYPT_BLOCK;
                }
                byte[] decryptedBlock = cipher.doFinal(data, offset, inputLen);
                bos.write(decryptedBlock);
            }
    
            bos.close();
            return bos.toByteArray();
        }
    
        /**
         * 分块公钥解密
         *
         * @param data
         * @param _publicKey
         */
        public static byte[] decryptWithPublicKeyBlock(byte[] data, String _publicKey) throws Exception {
            int blockCount = (data.length / DECRYPT_BLOCK);
            if ((data.length % DECRYPT_BLOCK) != 0) {
                blockCount += 1;
            }
            ByteArrayOutputStream bos = new ByteArrayOutputStream(blockCount * DECRYPT_BLOCK);
            Cipher cipher = Cipher.getInstance(ECB_PADDING);
            cipher.init(Cipher.DECRYPT_MODE, loadPublicKey(_publicKey));
            for (int offset = 0; offset < data.length; offset += DECRYPT_BLOCK) {
                int inputLen = (data.length - offset);
                if (inputLen > DECRYPT_BLOCK) {
                    inputLen = DECRYPT_BLOCK;
                }
                byte[] decryptedBlock = cipher.doFinal(data, offset, inputLen);
                bos.write(decryptedBlock);
            }
    
            bos.close();
            return bos.toByteArray();
        }
    
        /**
         * 用私钥加密
         */
        public static byte[] encryptDataPrivate(byte[] data, PrivateKey privateKey) {
            try {
                // 对数据加密
                Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
                cipher.init(Cipher.ENCRYPT_MODE, privateKey);
    
                return cipher.doFinal(data);
            } catch (Exception e) {
                return null;
            }
        }
    
        /**
         * 分块私钥加密
         *
         * @param data
         * @param key
         */
        public static byte[] encryptWithPrivateKeyBlock(byte[] data, byte[] key) throws Exception {
            int blockCount = (data.length / ENCRYPT_BLOCK);
    
            if ((data.length % ENCRYPT_BLOCK) != 0) {
                blockCount += 1;
            }
            ByteArrayOutputStream bos = new ByteArrayOutputStream(blockCount * ENCRYPT_BLOCK);
            Cipher cipher = Cipher.getInstance(ECB_PADDING);
            cipher.init(Cipher.ENCRYPT_MODE, getPrivateKey(key));
    
            for (int offset = 0; offset < data.length; offset += ENCRYPT_BLOCK) {
                int inputLen = (data.length - offset);
                if (inputLen > ENCRYPT_BLOCK) {
                    inputLen = ENCRYPT_BLOCK;
                }
                byte[] encryptedBlock = cipher.doFinal(data, offset, inputLen);
                bos.write(encryptedBlock);
            }
    
            bos.close();
            return bos.toByteArray();
        }
    
        /**
         * 用私钥解密
         */
        public static byte[] decryptDataPrivate(byte[] data, PrivateKey privateKey) {
            try {
                // 对数据解密
                Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
                cipher.init(Cipher.DECRYPT_MODE, privateKey);
                return cipher.doFinal(data);
            } catch (Exception e) {
                return null;
            }
        }
    
        /**
         * 分块私钥解密
         *
         * @param data
         * @param key
         */
        public static byte[] decryptWithPrivateKeyBlock(byte[] data, byte[] key) throws Exception {
            int blockCount = (data.length / DECRYPT_BLOCK);
            if ((data.length % DECRYPT_BLOCK) != 0) {
                blockCount += 1;
            }
            ByteArrayOutputStream bos = new ByteArrayOutputStream(blockCount * DECRYPT_BLOCK);
            Cipher cipher = Cipher.getInstance(ECB_PADDING);
            cipher.init(Cipher.DECRYPT_MODE, getPrivateKey(key));
            for (int offset = 0; offset < data.length; offset += DECRYPT_BLOCK) {
                int inputLen = (data.length - offset);
    
                if (inputLen > DECRYPT_BLOCK) {
                    inputLen = DECRYPT_BLOCK;
                }
    
                byte[] decryptedBlock = cipher.doFinal(data, offset, inputLen);
                bos.write(decryptedBlock);
            }
    
            bos.close();
            return bos.toByteArray();
        }
    
        /**
         * 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
         *                   RSA - 当前我的后台给的公钥的生成算法是RSA
         */
        public static PublicKey loadPublicKey(String publicKeyStr) throws Exception {
            try {
                byte[] buffer = Base64Util.decode(publicKeyStr);
                KeyFactory keyFactory = KeyFactory.getInstance(RSA);
                X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);
                return 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<br>
         * 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 = Base64Util.decode(privateKeyStr);
                PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
                KeyFactory keyFactory = KeyFactory.getInstance(RSA);
                return 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 in 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('\r');
                }
            }
    
            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());
        }
    
        /**
         * 打印公钥信息
         *
         * @param privateKey
         */
        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());
    
        }
    
        /**
         * 得到密钥字符串(经过base64编码)
         */
        public static String getKeyString(Key key) throws Exception {
            byte[] keyBytes = key.getEncoded();
            String s = Base64Util.encode(keyBytes);
            return s;
        }
    
        /**
         * 16进制字符串转字节数组
         *
         * @param src 16进制字符串
         * @return 字节数组
         * @throws
         */
        public static byte[] hexString2Bytes(String src) {
            int l = src.length() / 2;
            byte[] ret = new byte[l];
            for (int i = 0; i < l; i++) {
                ret[i] = (byte) Integer
                        .valueOf(src.substring(i * 2, i * 2 + 2), 16).byteValue();
            }
            return ret;
        }
    
        /**
         * 16进制字符串转字符串
         *
         * @param src 16进制字符串
         * @return 字节数组
         * @throws
         */
        public static String hexString2String(String src) {
            String temp = "";
            for (int i = 0; i < src.length() / 2; i++) {
                temp = temp
                        + (char) Integer.valueOf(src.substring(i * 2, i * 2 + 2),
                        16).byteValue();
            }
            return temp;
        }
    
        /**
         * 字符串转16进制字符串
         *
         * @param strPart 字符串
         * @return 16进制字符串
         * @throws
         */
        public static String string2HexString(String strPart) {
            StringBuffer hexString = new StringBuffer();
            for (int i = 0; i < strPart.length(); i++) {
                int ch = (int) strPart.charAt(i);
                String strHex = Integer.toHexString(ch);
                hexString.append(strHex);
            }
            return hexString.toString();
        }
    
        /**
         * 字节数组转16进制字符串
         *
         * @param b 字节数组
         * @return 16进制字符串
         * @throws
         */
        public static String bytes2HexString(byte[] b) {
            StringBuffer result = new StringBuffer();
            String hex;
            for (int i = 0; i < b.length; i++) {
                hex = Integer.toHexString(b[i] & 0xFF);
                if (hex.length() == 1) {
                    hex = '0' + hex;
                }
                result.append(hex.toUpperCase());
            }
            return result.toString();
        }
    }
    
    

    Base64Util.java - Base64解压处理,采用了android本身提供的方式

    import android.util.Base64;
    
    import java.io.UnsupportedEncodingException;
    
    public class Base64Util {
    
        /******************************************非官方**************************************/
        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) {
            return decodePublic(data);
        }
    
        /**
         * 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 = 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");
        }
    
        private static String decodePublic(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();
        }
    
        /******************************************官方**************************************/
        /**
         * 【官】解密
         * @param str - 纯字母,就不搞utf-8编码了
         * @return
         */
        public static byte[] decodeToBytes(String str){
            //        try {
            //            return Base64.decode(str.getBytes("utf-8"), Base64.DEFAULT);
            //        } catch (UnsupportedEncodingException e) {
            //            e.printStackTrace();
            //        }
            //        return null;
            return Base64.decode(str.getBytes(), Base64.DEFAULT);
        }
    }
    

    基本没啥问题了

    [图片上传中...(image-d836fe-1579151205237-4)]

    问题:

    1. 如果不分块解密可能会报错: - 一下不能进行太多字节解密

      javax.crypto.IllegalBlockSizeException: input must be under 256 bytes
    

    2. 具体忘了,应该也是rsa获取公钥出的问题...

    java.lang.ArrayIndexOutOfBoundsException: too much data for RSA block
    

    3. 获取公钥方式key出问题,可能出现 ,具体是loadPublicKey(String publickey)方法,里面涉及到SSLX509Certificate等问题,这具体看后台加密的方式

     java.security.spec.InvalidKeySpecException: com.android.org.conscrypt.OpenSSLX509CertificateFactory$ParsingException: Error parsing public key
    
    java.security.spec.InvalidKeySpecException: encoded key spec not recognized: failed to construct sequence from byte[]: unknown tag 13 encountered
    

    4. 记得公钥去掉-----BEGIN PUBLIC KEY----- -----END PUBLIC KEY-----

    [图片上传中...(image-f2b976-1579151205236-3)]

    我的格式如下(\n没去掉试哈哈,保留了,你可以去掉试试。。嘻嘻) - 我定义在cpp文件了,打包成了so,让破解更难些。。。另外加了**签名校验 参考 **CSDN-专业IT技术社区-登录,防止so直接被调用...

    [图片上传中...(image-796b50-1579151205236-2)]

    cryptor.cpp - 直接给出来吧。需要可以参考

    #include <jni.h>
    #include <string>
    
    const char *app_signature_sha1="E561477307CDxxxxxxxx815EC4A014DF";
    const char HexCode[]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
    
    extern "C" JNIEXPORT jstring JNICALL
    Java_com_lieyun_rsa_CryptorNatvie_getPubliscKey(
            JNIEnv* env,
            jclass type,
            jobject context_object) {
        jclass context_class = env->GetObjectClass(context_object);
    
        //context.getPackageManager()
        jmethodID methodId = env->GetMethodID(context_class, "getPackageManager", "()Landroid/content/pm/PackageManager;");
        jobject package_manager_object = env->CallObjectMethod(context_object, methodId);
        if (package_manager_object == NULL) {
            std::string rsa_keysbhello = "hello";
            return env->NewStringUTF(rsa_keysbhello.c_str());
        }
    
        //context.getPackageName()
        methodId = env->GetMethodID(context_class, "getPackageName", "()Ljava/lang/String;");
        jstring package_name_string = (jstring)env->CallObjectMethod(context_object, methodId);
        if (package_name_string == NULL) {
            std::string rsa_keysbheys = "heys";
            return env->NewStringUTF(rsa_keysbheys.c_str());
        }
        env->DeleteLocalRef(context_class);
    
        //PackageManager.getPackageInfo(Sting, int)
        //public static final int GET_SIGNATURES= 0x00000040;
        jclass pack_manager_class = env->GetObjectClass(package_manager_object);
        methodId = env->GetMethodID(pack_manager_class, "getPackageInfo", "(Ljava/lang/String;I)Landroid/content/pm/PackageInfo;");
        env->DeleteLocalRef(pack_manager_class);
        jobject package_info_object = env->CallObjectMethod(package_manager_object, methodId, package_name_string, 0x40);
        if (package_info_object == NULL) {
            std::string rsa_keysbhey = "hey";
            return env->NewStringUTF(rsa_keysbhey.c_str());
        }
        env->DeleteLocalRef(package_manager_object);
    
        //PackageInfo.signatures[0]
        jclass package_info_class = env->GetObjectClass(package_info_object);
        jfieldID fieldId = env->GetFieldID(package_info_class, "signatures", "[Landroid/content/pm/Signature;");
        env->DeleteLocalRef(package_info_class);
        jobjectArray signature_object_array = (jobjectArray)env->GetObjectField(package_info_object, fieldId);
        if (signature_object_array == NULL) {
            std::string rsa_keysbfuck = "fuck";
            return env->NewStringUTF(rsa_keysbfuck.c_str());
        }
        jobject signature_object = env->GetObjectArrayElement(signature_object_array, 0);
        env->DeleteLocalRef(package_info_object);
    
        //Signature.toByteArray()
        jclass signature_class = env->GetObjectClass(signature_object);
        methodId = env->GetMethodID(signature_class, "toByteArray", "()[B");
        env->DeleteLocalRef(signature_class);
        jbyteArray signature_byte = (jbyteArray) env->CallObjectMethod(signature_object, methodId);
    
        //new ByteArrayInputStream - 这里报错了,但是不影响打包和运行
        jclass byte_array_input_class=env->FindClass("java/io/ByteArrayInputStream");
        methodId=env->GetMethodID(byte_array_input_class,"<init>","([B)V");
        jobject byte_array_input=env->NewObject(byte_array_input_class,methodId,signature_byte);
    
        //CertificateFactory.getInstance("X.509")
        jclass certificate_factory_class=env->FindClass("java/security/cert/CertificateFactory");
        methodId=env->GetStaticMethodID(certificate_factory_class,"getInstance","(Ljava/lang/String;)Ljava/security/cert/CertificateFactory;");
        jstring x_509_jstring=env->NewStringUTF("X.509");
        jobject cert_factory=env->CallStaticObjectMethod(certificate_factory_class,methodId,x_509_jstring);
    
        //certFactory.generateCertificate(byteIn);
        methodId=env->GetMethodID(certificate_factory_class,"generateCertificate",("(Ljava/io/InputStream;)Ljava/security/cert/Certificate;"));
        jobject x509_cert=env->CallObjectMethod(cert_factory,methodId,byte_array_input);
        env->DeleteLocalRef(certificate_factory_class);
    
        //cert.getEncoded()
        jclass x509_cert_class=env->GetObjectClass(x509_cert);
        methodId=env->GetMethodID(x509_cert_class,"getEncoded","()[B");
        jbyteArray cert_byte=(jbyteArray)env->CallObjectMethod(x509_cert,methodId);
        env->DeleteLocalRef(x509_cert_class);
    
        //MessageDigest.getInstance("SHA1")
        jclass message_digest_class=env->FindClass("java/security/MessageDigest");
        methodId=env->GetStaticMethodID(message_digest_class,"getInstance","(Ljava/lang/String;)Ljava/security/MessageDigest;");
        jstring sha1_jstring=env->NewStringUTF("SHA1");
        jobject sha1_digest=env->CallStaticObjectMethod(message_digest_class,methodId,sha1_jstring);
    
        //sha1.digest (certByte)
        methodId=env->GetMethodID(message_digest_class,"digest","([B)[B");
        jbyteArray sha1_byte=(jbyteArray)env->CallObjectMethod(sha1_digest,methodId,cert_byte);
        env->DeleteLocalRef(message_digest_class);
    
        //toHexString
        jsize array_size=env->GetArrayLength(sha1_byte);
        jbyte* sha1 =env->GetByteArrayElements(sha1_byte,NULL);
        char *hex_sha=new char[array_size*2+1];
        for (int i = 0; i <array_size ; ++i) {
            hex_sha[2*i]=HexCode[((unsigned char)sha1[i])/16];
            hex_sha[2*i+1]=HexCode[((unsigned char)sha1[i])%16];
        }
        hex_sha[array_size*2]='\0';
        //比较签名
        if (strcmp(hex_sha,app_signature_sha1)==0)
        {
            std::string rsa_key = "MIIBIjxxxxxxxB\n";
            return env->NewStringUTF(rsa_key.c_str());
        } else{
            std::string rsa_keysb = "sb";
            return env->NewStringUTF(rsa_keysb.c_str());
        }
    }
    
    //jobject getApplication(JNIEnv *env) {
    //    jclass localClass = (*env)->FindClass(env,"android/app/ActivityThread");
    //    if (localClass!=NULL)
    //    {
    //        // LOGI("class have find");
    //        jmethodID getapplication = (*env)->GetStaticMethodID(env,localClass, "currentApplication", "()Landroid/app/Application;");
    //        if (getapplication!=NULL)
    //        {
    //            jobject application = (*env)->CallStaticObjectMethod(env,localClass, getapplication);
    //            return application;
    //        }
    //        return NULL;
    //    }
    //    return NULL;
    //}
    
    //void exitApplication(JNIEnv *env, jint flag){
    //    jclass temp_clazz = NULL;
    //    jmethodID mid_static_method;
    //    // 1、从classpath路径下搜索ClassMethod这个类,并返回该类的Class对象
    //    temp_clazz =(*env)->FindClass(env,"java/lang/System");
    //    mid_static_method = (*env)->GetStaticMethodID(env,temp_clazz,"exit","(I)V");
    //    (*env)->CallStaticVoidMethod(env,temp_clazz,mid_static_method,flag);
    //    (*env)->DeleteLocalRef(env,temp_clazz);
    //}
    

    [图片上传中...(image-8a477c-1579151205236-1)]

    上面这是签名文件的sha1值,替换自己的

    [图片上传中...(image-cb7921-1579151205236-0)]

    上面这是rsa公钥字符串(处理了begin和end。。\n保留了。如果有问题可以再多调试)

    到此基本就搞定了rsa界面,然后做了基本的so加密处理。。。顺便复习了下native编程。。哇咔咔。。。加油。。

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        本文标题:Android-rsa解密服务端给的加密过的内容,利用rsa公钥

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