最近公司要数据加密，要求用c++进行解密，android还是很容易反编译，而so文件反编译难一点，在网上找到了开源的代码从openssl中抽出了AES ecb cbc的代码，可是加密完发现数据是十六进制的，同样解密的数据也是十六进制的，没办法只能转换成字符串，在网上找了一些转换的代码

加密解密c++代码

#include <sstream>
extern "C"{
#include "aes.h"
}
//把字符串转成十六进制字符串
std::string char2hex(std::string s)
{
    std::string ret;
    for (unsigned i = 0; i != s.size(); ++i)
    {
        char hex[5];
        sprintf(hex, "%.2x", (unsigned char)s[i]);
        ret += hex;
    }
    return ret;
}
//把十六进制字符串转成字符串
std::string hex2char(std::string s)
{
    std::string ret;
    int length = (int) s.length();
    for (int i = 0; i <length ; i+=2) {
        std::string buf = "0x"+s.substr(i,2);
        unsigned int value;
        sscanf(buf.c_str(), "%x", &value);
        ret += ((char)value);
    }
    return ret;
}
int hexCharToInt(char c){
    if(c >= '0' && c <= '9') return (c - '0');
    if(c >= 'A' && c <= 'F') return (c - 'A'+10);
    if(c >= 'a' && c <= 'f') return (c - 'a'+10);
    return 0;
}

//十六进制字符串转成十六进制数组
char * hexstringToBytes(std::string s){
    int sz = (int) s.length();
    char  *ret = new char[sz/2];
    for (int i = 0; i < sz; i+=2) {
        ret[i/2] = (char)((hexCharToInt(s.at(i)) << 4)|hexCharToInt(s.at(i+1)));
    }
    return ret;
}
//十六进制数组转成十六进制字符串
std::string bytestohexstring(char *bytes,int bytelength){
    std::string str("");
    std::string str2("0123456789abcdef");
    for (int i = 0; i < bytelength; ++i) {
        int b;
        b = 0x0f&(bytes[i]>>4);
        char s1 = str2.at(b);
        str.append(1,str2.at(b));
        b = 0x0f&bytes[i];
        str.append(1,str2.at(b));
//        char s2 = str2.at(b);
    }
    return str;
}
//加密
std::string EncodeAES(const unsigned char *master_key,std::string data,const unsigned char *iv){
    AES_KEY key;
    AES_set_encrypt_key(master_key, 128, &key);

    unsigned char ivc[AES_BLOCK_SIZE];

    std::string data_bak = data.c_str();
    unsigned int data_length = (unsigned int) data_bak.length();
    int padding = 0;
    if (data_bak.length() % AES_BLOCK_SIZE >= 0)
    {
        padding = (int) (AES_BLOCK_SIZE - data_bak.length() % AES_BLOCK_SIZE);
    }
    data_length += padding;
    while (padding > 0)
    {
        data_bak += '';
        padding--;
    }

    memcpy( ivc, iv, AES_BLOCK_SIZE*sizeof(char));
    std::string encryhex;
    for(unsigned int i = 0; i < data_length/AES_BLOCK_SIZE; i++)
    {
        std::string str16 = data_bak.substr(i*AES_BLOCK_SIZE, AES_BLOCK_SIZE);
        unsigned char out[AES_BLOCK_SIZE];
        memset(out, 0, AES_BLOCK_SIZE);
        AES_cbc_encrypt((const unsigned char *) str16.c_str(), out, 16, &key, ivc, AES_ENCRYPT);
        encryhex += bytestohexstring((char *) out, AES_BLOCK_SIZE);
    }
    return encryhex;

}
//解密
std::string DecodeAES(const unsigned char *master_key,std::string data,const unsigned char *iv){
    AES_KEY key;
    AES_set_decrypt_key(master_key, 128, &key);

    unsigned char ivc[AES_BLOCK_SIZE];
    memcpy( ivc, iv, AES_BLOCK_SIZE*sizeof(char));
    std::string ret;
    for(unsigned int i = 0; i < data.length()/(AES_BLOCK_SIZE*2); i++)
    {
        std::string str16 = data.substr(i*AES_BLOCK_SIZE*2, AES_BLOCK_SIZE*2);
        unsigned char out[AES_BLOCK_SIZE];
        memset(out, 0, AES_BLOCK_SIZE);
        char *buf = hexstringToBytes(str16);
        AES_cbc_encrypt((const unsigned char *)buf , out, AES_BLOCK_SIZE, &key, ivc, AES_DECRYPT);
        delete(buf);
        ret += hex2char(bytestohexstring((char *) out, AES_BLOCK_SIZE));
    }
    return ret;
}

extern "C"
JNIEXPORT jstring JNICALL
Java_com_example_aes_MainActivity_encryptString(JNIEnv *env, jclass type, jstring str_) {
    const char *str = env->GetStringUTFChars(str_, 0);

    // TODO

    const unsigned char *master_key = (const unsigned char *) "1234567890abcdef";
    const unsigned char *iv = (const unsigned char *) "90abcdef12345678";

    std::string h = EncodeAES(master_key, str, iv);

    env->ReleaseStringUTFChars(str_, str);
    return env->NewStringUTF(h.c_str());
}extern "C"
JNIEXPORT jstring JNICALL
Java_com_example_aes_MainActivity_decryptString(JNIEnv *env, jclass type, jstring str_) {
    const char *str = env->GetStringUTFChars(str_, 0);

    // TODO

    const unsigned char *master_key = (const unsigned char *) "1234567890abcdef";

    const unsigned char *iv = (const unsigned char *) "90abcdef12345678";

    std::string s = DecodeAES(master_key,str,iv);
    env->ReleaseStringUTFChars(str_, str);

    return env->NewStringUTF(s.c_str());
}

java代码

public native static String encryptString(String str);

public native static String decryptString(String str);

String s = encryptString("abcdefg");
Log.d(TAG,"encrypt:"+s);
s = decryptString(s);
Log.d(TAG,"decrypt:"+s);

效果

加密测试网站