c语言实现rsa nopadding非对称加密算法（openssl api方式），匹配java后端 bouncycastle

公私钥：
—–BEGIN PUBLIC KEY—–
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC32V2IAfotG8bZhPF8/Bx8y65g
EDycAMyTWmvpPCfagEKORO/WvdkTYim7yhG/+pMs58wu86edP3LOK73VVlG1eeOg
shGVLsKRMYkFRFJ2a81VL2eOaZ8EyZazJ9bkGbNz+JRecx4LkPHdEZTRiSr7zQxN
f0UWR9Dxna1T7/C3twIDAQAB
—–END PUBLIC KEY—–

—–BEGIN RSA PRIVATE KEY—–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—–END RSA PRIVATE KEY—–

java中的公私钥 (只是去掉了头尾和换行，这样才能在java中使用):
static String prikey1024 = “MIICXQIBAAKBgQC32V2IAfotG8bZhPF8/Bx8y65gEDycAMyTWmvpPCfagEKORO/WvdkTYim7yhG/+pMs58wu86edP3LOK73VVlG1eeOgshGVLsKRMYkFRFJ2a81VL2eOaZ8EyZazJ9bkGbNz+JRecx4LkPHdEZTRiSr7zQxNf0UWR9Dxna1T7/C3twIDAQABAoGBAIS0EDAhBTzUJOdTb6AAtmtZ9eb/MVCFvyTJisTSmA2+sMvSdLAzXuH/5BHZnJBPRTaPpjFpzF3Ts4GfzymTYev762lDaVNTId/md6mOcDHdkrBMpjLQcdJa8kv42gdxb9+1N+6X4wRh7DyIsow2gCKwrWE1rpf3M7xnqIBI3qSpAkEA3VzD/PAU9aDni3VJwEsML2eTJ52FdVAUtlvfaSnbUIgnTHNldCjVQUyT99bLs5FsRILnxM1+iFmHdVUvZgGN6wJBANSd6NdtTcijOqy9wb/cqTaInCLNObGmLOHSrJcngpWOXtrrk5ZV9JpKiNFycvM0j6+WS0aVERWjb3xo9msarmUCQAk1IJnWyqhk5vywBj9PX9Rg9IgDT1fP2uyy6ZoQOaUh5LCTZDbus+AhdU4ryxFPDTfUUhuniInXX4EL6ArQKb0CQCY9XGJag1Hhoazt2An02u429bYAqS69T3cyF957ua3CVGcVVY8FWJ/jZeYdqnT5cBpJcrJ4HwGASo3apu8udk0CQQCzJ28e0WVCIwxgYK81FZgTxusaSjtkv4Dbz0BXvZLHNX6zYO1fqM1Cm/FMqGtPvI8/O3AVJrcNeo4lgKvyDQVv”;
static String pubkey1024 = “MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC32V2IAfotG8bZhPF8/Bx8y65gEDycAMyTWmvpPCfagEKORO/WvdkTYim7yhG/+pMs58wu86edP3LOK73VVlG1eeOgshGVLsKRMYkFRFJ2a81VL2eOaZ8EyZazJ9bkGbNz+JRecx4LkPHdEZTRiSr7zQxNf0UWR9Dxna1T7/C3twIDAQAB”;

java后端 使用bouncycastle的代码(bouncycastle需要去其官网下载http://www.bouncycastle.org/download/bcprov-debug-jdk15on-158.jar,或者下载其他可用版本也行):

 Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider()); public static String encrypt(String publicKey, String plainTextData) throws Exception {//        if (TextUtils.isEmpty(publicKey)) {//            throw new Exception("加密公钥为空, 请设置");//        }        X509EncodedKeySpec bobPubKeySpec = new X509EncodedKeySpec(Base64.decode(publicKey,Base64.DEFAULT));        KeyFactory keyFactory = KeyFactory.getInstance("RSA");        PublicKey pubKey = keyFactory.generatePublic(bobPubKeySpec);        Cipher cipher;        try {            cipher = Cipher.getInstance("RSA/NONE/nopadding");            cipher.init(Cipher.ENCRYPT_MODE, pubKey);            byte[] output = cipher.doFinal(plainTextData.getBytes("UTF-8"));            return Base64.encodeToString(output, Base64.NO_WRAP);        } catch (Exception e) {            e.printStackTrace();            throw new Exception();        }    }    public static String decrypt(String privateKey, String cipherData) throws Exception {        if (privateKey == null) {            throw new Exception("解密私钥为空, 请设置");        }        PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec(Base64.decode(privateKey,Base64.DEFAULT));        KeyFactory keyf = KeyFactory.getInstance("RSA");        PrivateKey myprikey = keyf.generatePrivate(priPKCS8);        Cipher cipher = null;        try {            cipher = Cipher.getInstance("RSA/NONE/NoPadding");            cipher.init(Cipher.DECRYPT_MODE, myprikey);            byte[] output = cipher.doFinal(Base64.decode(cipherData,Base64.DEFAULT));            return new String(output);        } catch (Exception e) {            e.printStackTrace();            throw new Exception();        }    }

c语言通过编译openssl并调用api实现java中的RSA/NONE/NoPadding非对称加解密算法，代码(注意加密后要进行base64编码，解密前要进行base64解码):

string decryptRSA(const std::string& data) {    int ret, flen;    BIO *bio = NULL;    RSA *r = NULL;    if ((bio = BIO_new_mem_buf((void *)prikey1024, -1)) == NULL)       //从字符串读取RSA私钥    {        //LOGE("BIO_new_mem_buf failed!\n");    }    //    r = PEM_read_bio_RSAPrivateKey(bio, NULL, NULL, NULL);    r = RSA_new();    PEM_read_bio_RSAPrivateKey(bio, &r, 0, 0);//读取私钥    flen = RSA_size(r);    static std::string gkbn;    gkbn.clear();    const char *gkbnP = gkbn.c_str();    char de[512] = {0};    memset(de, 0, (size_t)(512));    const char *dataP = data.c_str();    //RSA_private_encrypt  rsa_ossl_private_decrypt    ret = RSA_private_encrypt(flen, (const unsigned char *)dataP, (unsigned char *)de, r,        RSA_NO_PADDING);//RSA_NO_PADDING //RSA_PKCS1_PADDING    RSA_free(r);    BIO_free(bio);    CRYPTO_cleanup_all_ex_data(); //清除管理CRYPTO_EX_DATA的全局hash表中的数据，避免内存泄漏    char *result_c;    int len;    for (size_t i = 0; i < flen; i++)    {        if (de[i] != '\0') {            result_c = &de[i];            break;        }    }    len = strlen(result_c);    printf("\ndecrypto:%s\n", result_c);    gkbn.assign(result_c);    //    LOGD("解密明文：%s ret:%d",gkbn.c_str(), ret);    return  gkbn;string encryptRSA(const std::string& data, int *lenreturn) {    int ret, flen,bio_len;    BIO *bio = NULL;    RSA *r = NULL;    if ((bio = BIO_new_mem_buf((void *)pubkey1024, strlen(pubkey1024))) == NULL)       //从字符串读取RSA公钥    {        //LOGE("BIO_new_mem_buf failed!\n");    }    PEM_read_bio_RSA_PUBKEY(bio, &r, 0, 0);    flen = RSA_size(r);    lenreturn = &flen;    static std::string gkbn;    gkbn.clear();    unsigned char *src = NULL;    unsigned char *dst = NULL;    src = (unsigned char *)OPENSSL_malloc(flen * 2);//填充0 到 128 长度    dst = (unsigned char *)OPENSSL_malloc(flen);    memset(src, 0, flen * 2);    memcpy(src, data.c_str(), data.size());    memset(dst, 0, flen + 1);    //  RSA_PKCS1_PADDING 最大加密长度 为 128 -11    //RSA_NO_PADDING 最大加密长度为  128    ret = RSA_public_encrypt(flen, src, dst, r, RSA_NO_PADDING);//RSA_NO_PADDING //RSA_PKCS1_PADDING    gkbn.assign((char *)dst,ret);    RSA_free(r);    //OPENSSL_free(src);    //OPENSSL_free(dst);    BIO_free(bio);    CRYPTO_cleanup_all_ex_data(); //清除管理CRYPTO_EX_DATA的全局hash表中的数据，避免内存泄漏    return  gkbn;}}

测试：
c语言加密字符串”ceshi123”，通过调用encryptRSA函数加密

char origin_text[117] = "ceshi123";int retlen;string crypto = encryptRSA(origin_text,&retlen);crypto = TDBASE64::base64_encodestring(crypto);printf("%s", crypto.c_str());

得到结果:PC5At5PvCitwSio5TQK1gj/vsp3ffQMnu6LpXTJyhwZbCOS3t+PFZoYvUtUyZNvstp7KZMie8CoAVDbhfJP2H+AZDcnVQljKAQTpeb+VjjZJGQzFV42cxzKgNo2Oq3M/7EoAvJYWp7XFE7Y1/lOJSFdcfFjDD3zFX26I4c+TzDI=，然后用java解密，java解密后的结果为 :

发现末尾有乱码，暂时不管，后文再讨论
现在使用java加密”ceshi123”得到结果B3I3nI+DnI+Y8W8rzNOs9cRhWjfFu0CW+ac3Cf/b/vgR3fm/vQkM1oekT1hhm9BaYSc1usby3il0X1dv41s6d6mtFImUjs1p0ILWChHG0Nu6cAilE34bFhkBdp1eQJJXJ8gJ/6FxsH7yfNOsgtF9H+bjYDJNkofl+MiHfsVQAU8=,发现和c语言加密的结果不一样，不管，用c语言解密，解密代码

string testText = "B3I3nI+DnI+Y8W8rzNOs9cRhWjfFu0CW+ac3Cf/b/vgR3fm/vQkM1oekT1hhm9BaYSc1usby3il0X1dv41s6d6mtFImUjs1p0ILWChHG0Nu6cAilE34bFhkBdp1eQJJXJ8gJ/6FxsH7yfNOsgtF9H+bjYDJNkofl+MiHfsVQAU8=";        testText = TDBASE64::base64_decodestring(testText);        decryptRSA(testText);     

观察结果发现结果有点怪异，虽然解密成功了，解密后的内存区域占用128个字节，但解密后的结果”ceshi123”并不在数组开始区域，而是在数组末尾，，后来通过翻看openssl源码发现，openssl在rsa nopadding下会在解密前和加密后进行填充，可以看到源码中的rsa_none.c源文件中的代码：

int RSA_padding_add_none(unsigned char *to, int tlen,                         const unsigned char *from, int flen){    if (flen > tlen) {        RSAerr(RSA_F_RSA_PADDING_ADD_NONE, RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);        return (0);    }    if (flen < tlen) {        RSAerr(RSA_F_RSA_PADDING_ADD_NONE, RSA_R_DATA_TOO_SMALL_FOR_KEY_SIZE);        return (0);    }    memcpy(to, from, (unsigned int)flen);    return (1);}int RSA_padding_check_none(unsigned char *to, int tlen,                           const unsigned char *from, int flen, int num){    if (flen > tlen) {        RSAerr(RSA_F_RSA_PADDING_CHECK_NONE, RSA_R_DATA_TOO_LARGE);        return (-1);    }    memset(to, 0, tlen - flen);    memcpy(to + tlen - flen, from, flen);    return (tlen);}

函数 RSA_padding_add_none 会在加密前调用，而 RSA_padding_check_none会在解密后调用，
针对明文”ceshi123”解密测试中发现 ，openssl内部解密调用 RSA_padding_check_none 时，tlen=128,flen=8,num=128，（num在这里好像没看到调用） ，调用memset(to, 0, tlen - flen);
memcpy(to + tlen - flen, from, flen) 后就导致了数组中前面全是0，明文在末尾的情况，
结论，openssl的rsa nopadding并不能与 java bouncycastle 的 rsa nopadding完全匹配，当然手动处理出现0的情况也是可以的，比如去掉结果中出现0的字符，但可能某些情况会出现bug，推荐使用rsa pkcs1padding方式，这种方式openssl 可以完美匹配java bouncycastle的算法，可以互相加解密而不会出现上面有0的情况 ，下一篇直接上java 和c语言调用openssl的RSA/NONE/PCKS1PADDING代码