Cryptopp iOS 使用 RSA加密解密和簽名驗證簽名

Cryptopp 是一個c++寫的功能完善的密碼學工具，類似於openssl

官網：https://www.cryptopp.com

以下主要演示Cryptopp 在iOS上的RSA加密解密簽名與驗證簽名

1. 編譯cryptopp為iOS上使用的靜態庫

   我整理好了一份 cryptopp5.6.2版本的打包腳本隨后在下面DEMO中一起發布，需要可自行下載

   編譯其他版本的，簡單修改腳本就行

   終端運行腳本

   sh build-cryptopp.sh 

   就會生成如下目錄結構，

   

  生成的靜態庫是通用版的，真機模擬器合並的，比較大200多M，實測打包之后幾百K，

  打包之后libcryptopp.a 和 include 的頭文件，在ios上使用

2. 將上述打包的靜態庫以及 頭文件導入DEMO工程CryptoppDemo

    將測試用的viewController.m 修改為 ViewController.mm

   主要為了實現 oc ,c++的混編

3. 使用 md5

    當然還支持其他hash算法   

-(NSData*)getMD5Value:(NSData*)data {
    CryptoPP::MD5 md5;
    byte digest[ CryptoPP::MD5::DIGESTSIZE ];
    
    md5.CalculateDigest(digest, (const byte*)[data bytes], [data length]);
    
    NSData * hashVale = [NSData dataWithBytes:digest length:sizeof digest];
    return hashVale;
}



    //MD5
    NSString *testStr = @"hello world md5";
    NSData *testDAT = [testStr dataUsingEncoding:NSUTF8StringEncoding];
    NSData *md5Dat = [self getMD5Value:testDAT];
    NSLog(@"%lu",md5Dat.length);
    NSMutableString *s = [NSMutableString string];
    unsigned char * hashValue = (byte *)[md5Dat bytes];
    
    int i;
    for (i = 0; i < [md5Dat length]; i++) {
        [s appendFormat:@"%02x", hashValue[i]];
    }
    NSLog(@"%@",s);

4. RSA 密鑰對生成

    //RSA 生成密鑰對
    char seed[1024]={1};
    unsigned int keyLength = 1024;
    char *privFilename = "/Users/cocoajin/Desktop/priKey.txt";
    char *pubFilename = "/Users/cocoajin/Desktop/pubKey.txt";
    
    CryptoPP::RandomPool randPool;
    randPool.IncorporateEntropy((byte *)seed, strlen(seed));
    
    CryptoPP::RSAES_OAEP_SHA_Decryptor priv(randPool, keyLength);
    CryptoPP::HexEncoder privFile(new CryptoPP::FileSink(privFilename));
    priv.DEREncode(privFile);
    privFile.MessageEnd();
    
    CryptoPP::RSAES_OAEP_SHA_Encryptor pub(priv);
    CryptoPP::HexEncoder pubFile(new CryptoPP::FileSink(pubFilename));
    pub.DEREncode(pubFile);
    pubFile.MessageEnd();

5. RSA 加密與解密

    //RSA 加密
    char seed[1024]={2};
    char *pubFilename = "/Users/cocoajin/Desktop/pubKey.txt";
    char *message = "hello ios cryptopp";
    printf("%s\n",message);
    CryptoPP::FileSource pubFile(pubFilename, true, new CryptoPP::HexDecoder);
    CryptoPP::RSAES_OAEP_SHA_Encryptor pub(pubFile);
    
    CryptoPP::RandomPool randPool;
    randPool.IncorporateEntropy((byte *)seed, strlen(seed));
    
    std::string encresult;
    CryptoPP::StringSource(message, true, new CryptoPP::PK_EncryptorFilter(randPool, pub, new CryptoPP::HexEncoder(new CryptoPP::StringSink(encresult))));
    std::cout << encresult << std::endl;
    
    
    //RSA 解密
    char *privFilename = "/Users/cocoajin/Desktop/priKey.txt";

    CryptoPP::FileSource privFile(privFilename, true, new CryptoPP::HexDecoder);
    CryptoPP::RSAES_OAEP_SHA_Decryptor priv(privFile);
    
    CryptoPP::AutoSeededRandomPool _rng;
    CryptoPP::RSAES_OAEP_SHA_Decryptor tpriv(_rng, 1024);

    std::string decresult;
    CryptoPP::StringSource(encresult.c_str(), true, new CryptoPP::HexDecoder(new CryptoPP::PK_DecryptorFilter(_rng, priv, new CryptoPP::StringSink(decresult))));
    std::cout << decresult << std::endl;

6. 簽名與驗證簽名  

    //RSA 簽名與較驗簽名
    char *privFilename = "/Users/cocoajin/Desktop/priKey.txt";
    char *pubFilename = "/Users/cocoajin/Desktop/pubKey.txt";

    char *signatureFilename = "/Users/cocoajin/Desktop/sin.txt";
    char *messageFileName = "/Users/cocoajin/Desktop/NOTES.txt";
    CryptoPP::FileSource privFile(privFilename, true, new CryptoPP::HexDecoder);

    
    //GlobalRNG
    CryptoPP::AutoSeededRandomPool _rng;
    CryptoPP::RSAES_OAEP_SHA_Decryptor tpriv(_rng, 1024);

    
    CryptoPP::RSASSA_PKCS1v15_SHA_Signer priv(privFile);
    CryptoPP::FileSource f(messageFileName, true, new CryptoPP::SignerFilter(_rng, priv, new CryptoPP::HexEncoder(new CryptoPP::FileSink(signatureFilename))));

     
    
    //驗證簽名
    CryptoPP::FileSource pubFile(pubFilename, true, new CryptoPP::HexDecoder);
    CryptoPP::RSASSA_PKCS1v15_SHA_Verifier pub(pubFile);
    
    CryptoPP::FileSource signatureFile(signatureFilename, true, new CryptoPP::HexDecoder);
    if (signatureFile.MaxRetrievable() != pub.SignatureLength())
    {
        printf("\nNO\n");
        return;
    }
    CryptoPP::SecByteBlock signature(pub.SignatureLength());
    signatureFile.Get(signature, signature.size());
    
    CryptoPP::VerifierFilter *verifierFilter = new CryptoPP::VerifierFilter(pub);
    verifierFilter->Put(signature, pub.SignatureLength());
    CryptoPP::FileSource ff(messageFileName, true, verifierFilter);
    printf("\n%d\n",verifierFilter->GetLastResult());

 

7. 其他相關cryptopp的用法可以參考：源碼test.cpp 

8. CryptoppDemo下載

     https://github.com/cocoajin/TDDDemo/tree/master/CryptoppDemo 

參考：

https://github.com/3ign0n/CryptoPP-for-iOS

https://my.oschina.net/u/566591/blog/168520