1 cocos2dx自带base64

#include <base/base64.h>
std::string OpensslTool::baseBase64Decode(const char *in)
{
    int inLen = strlen(in);
    unsigned char *out   ;
    int outLen = cocos2d::base64Decode((const unsigned char*)in, inLen, &out);

    std::string retStr((char*)out);
    if (out)
            free(out);
    return retStr.c_str();
}
std::string OpensslTool::baseBase64Encode(const char *in    )
{
    int inLen = strlen(in);
    char* out;
    int outLen = cocos2d::base64Encode((const unsigned char*)in, inLen, &out);
    std::string retStr(out);
    if (out) {
        free(out);
    }
    return retStr.c_str();
}

2, bio编码解码

#include <openssl/evp.h>
std::string OpensslTool::bioBase64Encode(const char *in)
{
    int len = strlen(in);
    char* out;
    int outLen = this->bioBase64Encode(in, len, &out);
    
    std::string retStr(out);
    if (out) {
        delete[] out;
    }
    return retStr;
}
int OpensslTool::bioBase64Encode(const char *in, int inLen, char **out)
{
    int outLen = 0;
    //1 创建b64类型bio
    BIO* b64 = BIO_new(BIO_f_base64());
    // 创建 mem类型bio
    BIO* bmem = BIO_new(BIO_s_mem());
    BUF_MEM* bptr = NULL;
    
    BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
    //2 构建bio链 b64 ->mem
    BIO_push(b64, bmem);
    //3 write操作 从前往后 b64编码->mem
    BIO_write(b64, in, inLen);
    BIO_flush(b64);
    //4 取出mem数据
    BIO_get_mem_ptr(b64, &bptr);
    
    outLen = bptr->length;
    *out = new char[outLen+1];
    memcpy(*out,bptr->data, outLen);
    
    out[outLen] = 0;
   
    BIO_free_all(b64);
    
    return outLen;

}

std::string OpensslTool::bioBase64Decode(const char *in)
{
    int len = strlen(in);
    char* out;
    int outLen = this->bioBase64Decode(in, len, &out);
    std::string retStr(out);
    if (out) {
        
        delete[] out;
    }
    return retStr;

}


int OpensslTool::bioBase64Decode(  const  char *in, int inLen, char **out   )
{
    BIO* b64 = BIO_new(BIO_f_base64());
    BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
    
    // 1 把数据存入mem类型bio
    BIO* bmem = BIO_new_mem_buf(in, inLen);//创建一个只读型bio(速度更快)
    // 2 构建bio链 b64 -> mem
    BIO_push(b64, bmem);
    
    *out = new char[inLen+1];
    memset(*out, 0, inLen+1);
    // 3 read操作 将从后往前执行 mem->b64解码->out
    BIO_read(b64, *out, inLen);
    //4 释放链
    
    BIO_free_all(bmem);
  
    return inLen;
}

3,evp编码解码

#include <openssl/evp.h>

std::string OpensslTool::evpBase64Encode(const char* in)
{
    int inLen = strlen(in);
    unsigned char* inBuffer = new unsigned char[inLen];
    memcpy(inBuffer, in, inLen);

    int decodeLen = inLen*2+1;
    unsigned char* decodeBuffer = new unsigned char[decodeLen];
    memset(decodeBuffer, 0, decodeLen);
    
    int outLen;

    EVP_ENCODE_CTX* ctx;
    ctx = EVP_ENCODE_CTX_new();
    EVP_EncodeInit(ctx);
    EVP_EncodeUpdate(ctx, decodeBuffer, &outLen, inBuffer, inLen);
    int tempLen;
    EVP_EncodeFinal(ctx, decodeBuffer, &tempLen);
    outLen += tempLen;
    
    char* out = new char[outLen+1];
    memcpy(out, decodeBuffer, outLen+1);
    out[outLen] = 0;
    std::string retStr(out);
    
    delete []inBuffer;
    delete []decodeBuffer;
    delete []out;
    
    EVP_cleanup();
    
    return retStr.c_str();
}


std::string OpensslTool::evpBase64Decode(const char*in)
{
    int inLen = strlen(in);
    unsigned char* inBuffer = new unsigned char[inLen];
    memcpy(inBuffer, in, inLen);
    
    int decodeLen = (((inLen+2)/4)*3)+1;
    unsigned char* decodeBuffer = new unsigned char[decodeLen];
    memset(decodeBuffer, 0, decodeLen);
    
    int outLen;
    
    EVP_ENCODE_CTX* ctx;
    ctx = EVP_ENCODE_CTX_new();
    EVP_DecodeInit(ctx);
    
    EVP_DecodeUpdate(ctx, decodeBuffer, &outLen, inBuffer, inLen);
    
    int tempLen;
    EVP_DecodeFinal(ctx, decodeBuffer, &tempLen);
    outLen += tempLen;
    
    char* out = new char[outLen];
    memcpy(out, decodeBuffer, outLen);
    
    std::string retStr(out);
    
    delete []inBuffer;
    delete []decodeBuffer;
    delete []out;
    
    
    return retStr.c_str();
}

遇到的问题

 1,api需要的参数基本都是unsigned char*类型，返回类型也有些是unsigned char*,最开始我是直接将char*强转为unsigned char*,然后返回unsigned char* 强转为char*,结果发现总有些数据返回不对。后来改成用memcpy直接复制，ok了。大致猜测是char*遇到\0就停止了

2，最开始写的时候，new空间使用的是固定值，导致数据超出我预设值时出错，后来改为动态申请了

3，EVP_ENCODE_CTX 网上找的资料用的不是指针，但是我这边会提示错误，提示Variable has incomplete type 'EVP_ENCODE_CTX' (aka 'evp_Encode_Ctx_st')，所以我这里改为指针了（evp.h里其他 结构体也会有这个错误提示，一样改为指针）

4，返回的unsigned char* 转char*时，可能需要补0