安卓与PHP间的RSA(openssl)交互加密的坑

这几天在写一个安卓的RSA公钥加密算法，用于跟PHP后台接口进行交互。在实践过程中发现了几个坑。其中我的公钥和私钥都是通过openssl生成的pem格式。

遇到的坑：

1.通过java的RSA公钥加密后获得的密文，在PHP中无法解密

2.通过java提取私钥时报错私钥格式不对

以下是相关关键代码[不完善的示例代码]

（该代码可直接百度，一大堆）

1.公钥私钥

 static String PUCLIC_KEY = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCfRTdcPIH10gT9f31rQuIInLwe" + "\r"
 + "7fl2dtEJ93gTmjE9c2H+kLVENWgECiJVQ5sonQNfwToMKdO0b3Olf4pgBKeLThra" + "\r"
 + "z/L3nYJYlbqjHC3jTjUnZc0luumpXGsox62+PuSGBlfb8zJO6hix4GV/vhyQVCpG" + "\r"
 + "9aYqgE7zyTRZYX9byQIDAQAB" + "\r";
 static String PRIVATE_KEY = "MIICdwIBADANBgkqhkiG9w0BAQEFAASCAmEwggJdAgEAAoGBAJ9FN1w8gfXSBP1/" + "\r"
 + "fWtC4gicvB7t+XZ20Qn3eBOaMT1zYf6QtUQ1aAQKIlVDmyidA1/BOgwp07Rvc6V/" + "\r"
 + "imAEp4tOGtrP8vedgliVuqMcLeNONSdlzSW66alcayjHrb4+5IYGV9vzMk7qGLHg" + "\r"
 + "ZX++HJBUKkb1piqATvPJNFlhf1vJAgMBAAECgYA736xhG0oL3EkN9yhx8zG/5RP/" + "\r"
 + "WJzoQOByq7pTPCr4m/Ch30qVerJAmoKvpPumN+h1zdEBk5PHiAJkm96sG/PTndEf" + "\r"
 + "kZrAJ2hwSBqptcABYk6ED70gRTQ1S53tyQXIOSjRBcugY/21qeswS3nMyq3xDEPK" + "\r"
 + "XpdyKPeaTyuK86AEkQJBAM1M7p1lfzEKjNw17SDMLnca/8pBcA0EEcyvtaQpRvaL" + "\r"
 + "n61eQQnnPdpvHamkRBcOvgCAkfwa1uboru0QdXii/gUCQQDGmkP+KJPX9JVCrbRt" + "\r"
 + "7wKyIemyNM+J6y1ZBZ2bVCf9jacCQaSkIWnIR1S9UM+1CFE30So2CA0CfCDmQy+y" + "\r"
 + "7A31AkB8cGFB7j+GTkrLP7SX6KtRboAU7E0q1oijdO24r3xf/Imw4Cy0AAIx4KAu" + "\r"
 + "L29GOp1YWJYkJXCVTfyZnRxXHxSxAkEAvO0zkSv4uI8rDmtAIPQllF8+eRBT/deD" + "\r"
 + "JBR7ga/k+wctwK/Bd4Fxp9xzeETP0l8/I+IOTagK+Dos8d8oGQUFoQJBAI4Nwpfo" + "\r"
 + "MFaLJXGY9ok45wXrcqkJgM+SN6i8hQeujXESVHYatAIL/1DgLi+u46EFD69fw0w+" + "\r" + "c7o0HLlMsYPAzJw="
 + "\r";
 

2.获取公钥并加密（PHP解密密文失败）

 String source = "hello world";
 PublicKey publicKey = RSAUtils.loadPublicKey(PUCLIC_KEY);
 byte[] encryptByte = RSAUtils.encryptData(source.getBytes(), publicKey);
 String afterencrypt = Base64Utils.encode(encryptByte);
 

3.获取私钥并解密（私钥获取失败）

 PrivateKey privateKey = RSAUtils.loadPrivateKey(PRIVATE_KEY);
 byte[] b1 = afterencrypt.getBytes();
 String text = new String(RSAUtils.decryptData(encryptByte, privateKey));
 

4.RSA算法工具类RSAUtils.class[不完善的示例代码]

 public final class RSAUtils
 {
 static String RSA = "RSA";
 public static byte[] encryptData(byte[] data, PublicKey publicKey) throws Exception
 {
 try
 {
 Cipher cipher = Cipher.getInstance(RSA);
 cipher.init(Cipher.ENCRYPT_MODE, publicKey);
 return cipher.doFinal(data);
 } 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");
 }
 }
 
 
public static byte[] decryptData(byte[] encryptedData, PrivateKey privateKey) throws Exception
{
    try
    {
        Cipher cipher = Cipher.getInstance(RSA);
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        return cipher.doFinal(encryptedData);
    } 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");  
    }         
}

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;
}

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;
}

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("not this suanfa");
    } catch (InvalidKeySpecException e)
    {
        throw new Exception("invalid public key");
    } catch (NullPointerException e)
    {
        throw new Exception("public key is null");
    }
}

public static PrivateKey loadPrivateKey(String privateKeyStr) throws Exception
{
    try
    {
        byte[] buffer = Base64Utils.decode(privateKeyStr);
        PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
        KeyFactory keyFactory = KeyFactory.getInstance(RSA);
        return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
    } catch (NoSuchAlgorithmException e)
    {
        throw new Exception("not this suanfa");
    } catch (InvalidKeySpecException e)
    {
        throw new Exception("invalid private key");
    } catch (NullPointerException e)
    {
        throw new Exception("private key is null");
    }
}
 
 
}
 

问题解决（填坑）

1.通过java的RSA公钥加密后获得的密文，在PHP中无法解密是因为JAVA和PHP加密模式和填充方式没有统一
2.通过java提取私钥时报错私钥格式不对，这个时候需要引入第三方算法提供商BouncyCastleProvider

于是乎

针对问题一，将加密过程RSAUtils.class中的公钥加密函数encryptData()中的算法实例获取

 Cipher cipher = Cipher.getInstance(RSA);
 

改成

 Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
 

即指定了ECB加密模式以及PKCS1Padding填充方式

---

针对问题二，在RSAUtils.class中的私钥加载函数loadPublicKey()中加入第三方算法提供商，以统一格式

 KeyFactory keyFactory = KeyFactory.getInstance(RSA);
 

改成

 KeyFactory keyFactory = KeyFactory.getInstance(RSA, new BouncyCastleProvider());
 

RSA算法工具类RSAUtils.class（完善版）

 public final class RSAUtils
 {
 static String RSA = "RSA";
 public static byte[] encryptData(byte[] data, PublicKey publicKey) throws Exception
 {
 try
 {
 Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
 cipher.init(Cipher.ENCRYPT_MODE, publicKey);
 return cipher.doFinal(data);
 } 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");
 }
 }
 
 
public static byte[] decryptData(byte[] encryptedData, PrivateKey privateKey) throws Exception
{
    try
    {
        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        return cipher.doFinal(encryptedData);
    } 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");  
    }         
}

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;
}

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;
}

public static PublicKey loadPublicKey(String publicKeyStr) throws Exception
{
    try
    {
        byte[] buffer = Base64Utils.decode(publicKeyStr);
        KeyFactory keyFactory = KeyFactory.getInstance(RSA, new BouncyCastleProvider());
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);
        return (RSAPublicKey) keyFactory.generatePublic(keySpec);
    } catch (NoSuchAlgorithmException e)
    {
        throw new Exception("not this suanfa");
    } catch (InvalidKeySpecException e)
    {
        throw new Exception("invalid public key");
    } catch (NullPointerException e)
    {
        throw new Exception("public key is null");
    }
}

public static PrivateKey loadPrivateKey(String privateKeyStr) throws Exception
{
    try
    {
        byte[] buffer = Base64Utils.decode(privateKeyStr);
        PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
        KeyFactory keyFactory = KeyFactory.getInstance(RSA, new BouncyCastleProvider());
        return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
    } catch (NoSuchAlgorithmException e)
    {
        throw new Exception("not this suanfa");
    } catch (InvalidKeySpecException e)
    {
        throw new Exception("invalid private key");
    } catch (NullPointerException e)
    {
        throw new Exception("private key is null");
    }
}
 
 
}
 

---

在此感谢网友的分享

1. JAVA与PHP之间的openssl交互加密
2. Java中使用OpenSSL生成的RSA公私钥进行数据加解密