c++ - 在 Windows 10 Visual Studio 2017 上为 FTPS 设置 Curl

Question

我正在尝试设置 Curl 以在 Windows 10 上的 Visual Studio 2017（社区）上与 FTPS 一起使用，但我不断收到奇怪的错误（错误包含在我尝试过的不同事物中）。我目前有 Curl 在 Mac 上为 FTPS 工作，目前我在 Linux 上不需要它。

我尝试过的事情：

1. 在Curls 下载页面下载二进制文件 要为 MacOs 设置 Curl，我所要做的就是下载 MacOs 二进制文件并链接它，所以这是我开始为 Windows 设置 Curl 的地方。然而，在下载二进制文件时，它只包含 .dll。它缺少标头和 .lib 文件。我尝试下载了大约 5 个其他二进制文件，每个都缺少至少一个基本文件。

2. 通过 vcpkg 安装 在获取二进制文件失败后，我意识到 Curl 可能在 vcpkg 上。我 ./vcpkg install curl从 vcpkg master 跑了。编译了几分钟，就成功了。然后我转到我的项目并将其链接到 curl，并进行了测试 ftps 传输。这是来自Curls 示例页面的示例

   #include <stdio.h>
   
   #include <curl/curl.h>
   
   /* <DESC>
    * Get a single file from an FTP server.
    * </DESC>
    */ 
   
   struct FtpFile {
     const char *filename;
     FILE *stream;
   };
   
   static size_t my_fwrite(void *buffer, size_t size, size_t nmemb, void *stream)
   {
     struct FtpFile *out = (struct FtpFile *)stream;
     if(out && !out->stream) {
      /* open file for writing */ 
        out->stream = fopen(out->filename, "wb");
       if(!out->stream)
         return -1; /* failure, can't open file to write */ 
     }
     return fwrite(buffer, size, nmemb, out->stream);
   }
   
   
   int main(void)
   {
     CURL *curl;
     CURLcode res;
     struct FtpFile ftpfile = {
       "C:\Users\myUser\Desktop\file.png", /* name to store the file as if successful */ 
       NULL
     };
   
     curl_global_init(CURL_GLOBAL_DEFAULT);
   
     curl = curl_easy_init();
     if(curl) {
       /*
        * You better replace the URL with one that works!
        */ 
       curl_easy_setopt(curl, CURLOPT_URL,
                    "ftp://my.ip.adress.here/path/to/file.png"); //Not actual address
       /* Define our callback to get called when there's data to be written */ 
       curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, my_fwrite);
       /* Set a pointer to our struct to pass to the callback */ 
       curl_easy_setopt(curl, CURLOPT_WRITEDATA, &ftpfile);
   
       /* Switch on full protocol/debug output */ 
       curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
   
       //Extra options to enable ssl (not included in example)
       curl_easy_setopt(FTPAgent,CURLOPT_USE_SSL,CURLUSESSL_ALL);
       curl_easy_setopt(FTPAgent,CURLOPT_SSL_VERIFYPEER,0L);
       curl_easy_setopt(FTPAgent,CURLOPT_USERNAME,"Username"); //Not actual username
       curl_easy_setopt(FTPAgent,CURLOPT_PASSWORD,"Password"); //Not actual password for obvious reasons
   
       res = curl_easy_perform(curl);
   
       /* always cleanup */ 
       curl_easy_cleanup(curl);
   
       if(CURLE_OK != res) {
         /* we failed */ 
         fprintf(stderr, "curl told us %d\n", res);
       }
     }
   
     if(ftpfile.stream)
       fclose(ftpfile.stream); /* close the local file */ 
   
     curl_global_cleanup();
   
     return 0;
   }
   

   该项目编译并运行，但是当它尝试下载文件时，调试控制台中出现错误，提示 Curl 与 FTPS 协议不兼容。我有意使用显式 FTPS，因为这是我将服务器配置为接受的内容，我可以使用 Mac 上的 Curl 和 Mac 和 Windows 的 FileZilla 的显式 FTPS 连接到它。如果有人知道如何解决这个问题，请lmk。暂时我已经放弃通过 vcpkg 使用 curl

3. 编译源代码我最后保存了这个，因为我找不到任何构建 Curl 的说明，但最终我找到了这个并按照答案中的说明进行操作，其中使用 curl 的版本来消除任何变量，而不是事实我在 VS2017 而不是 VS2013 上。我第二次这样做时，有人看着我这样做，以确保我正确地执行了所有步骤，所以我大约 90% 确定我正确地执行了这些说明。完成说明后，我使用了与上面相同的代码。它编译并运行没有错误，但是每当我尝试下载任何显着大小的文件时（我不太确定截止值，但 4kb 文件有效而 78kb 文件无效）它说解密数据失败需要更多数据约 20 次然后挂起：

   *   Trying my.ip.adress.here...
   * TCP_NODELAY set
   * Connected to my.ip.adress.here (my.ip.adress.here) port 21 (#0)
   < 220 (vsFTPd 2.2.2)
   > AUTH SSL
   < 234 Proceed with negotiation.
   * schannel: SSL/TLS connection with my.ip.adress.here port 21 (step 1/3)
   * schannel: disabled server certificate revocation checks
   * schannel: using IP address, SNI is not supported by OS.
   * schannel: sending initial handshake data: sending 147 bytes...
   * schannel: sent initial handshake data: sent 147 bytes
   * schannel: SSL/TLS connection with my.ip.adress.here port 21 (step 2/3)
   * schannel: failed to receive handshake, need more data
   * schannel: SSL/TLS connection with my.ip.adress.here port 21 (step 2/3)
   * schannel: encrypted data got 1034
   * schannel: encrypted data buffer: offset 1034 length 4096
   * schannel: a client certificate has been requested
   * schannel: SSL/TLS connection with my.ip.adress.here port 21 (step 2/3)
   * schannel: encrypted data buffer: offset 1034 length 4096
   * schannel: sending next handshake data: sending 349 bytes...
   * schannel: SSL/TLS connection with my.ip.adress.here port 21 (step 2/3)
   * schannel: encrypted data got 250
   * schannel: encrypted data buffer: offset 250 length 4096
   * schannel: SSL/TLS handshake complete
   * schannel: SSL/TLS connection with my.ip.adress.here port 21 (step 3/3)
   * schannel: stored credential handle in session cache
   > USER Username
   * schannel: client wants to read 16384 bytes
   * schannel: encdata_buffer resized 17408
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: encrypted data got 85
   * schannel: encrypted data buffer: offset 85 length 17408
   * schannel: decrypted data length: 34
   * schannel: decrypted data added: 34
   * schannel: decrypted data cached: offset 34 length 16384
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: decrypted data buffer: offset 34 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 34
   * schannel: decrypted data buffer: offset 0 length 16384
   < 331 Please specify the password.
   > PASS Password
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: encrypted data got 69
   * schannel: encrypted data buffer: offset 69 length 17408
   * schannel: decrypted data length: 23
   * schannel: decrypted data added: 23
   * schannel: decrypted data cached: offset 23 length 16384
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: decrypted data buffer: offset 23 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 23
   * schannel: decrypted data buffer: offset 0 length 16384
   < 230 Login successful.
   > PBSZ 0
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: encrypted data got 69
   * schannel: encrypted data buffer: offset 69 length 17408
   * schannel: decrypted data length: 20
   * schannel: decrypted data added: 20
   * schannel: decrypted data cached: offset 20 length 16384
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: decrypted data buffer: offset 20 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 20
   * schannel: decrypted data buffer: offset 0 length 16384
   < 200 PBSZ set to 0.
   > PROT P
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: encrypted data got 69
   * schannel: encrypted data buffer: offset 69 length 17408
   * schannel: decrypted data length: 23
   * schannel: decrypted data added: 23
   * schannel: decrypted data cached: offset 23 length 16384
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: decrypted data buffer: offset 23 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 23
   * schannel: decrypted data buffer: offset 0 length 16384
   < 200 PROT now Private.
   > PWD
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: encrypted data got 53
   * schannel: encrypted data buffer: offset 53 length 17408
   * schannel: decrypted data length: 9
   * schannel: decrypted data added: 9
   * schannel: decrypted data cached: offset 9 length 16384
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: decrypted data buffer: offset 9 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 9
   * schannel: decrypted data buffer: offset 0 length 16384
   < 257 "/"
   * Entry path is '/'
   > CWD path
   * ftp_perform ends with SECONDARY: 0
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: encrypted data got 85
   * schannel: encrypted data buffer: offset 85 length 17408
   * schannel: decrypted data length: 37
   * schannel: decrypted data added: 37
   * schannel: decrypted data cached: offset 37 length 16384
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: decrypted data buffer: offset 37 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 37
   * schannel: decrypted data buffer: offset 0 length 16384
   < 250 Directory successfully changed.
   > CWD to
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: encrypted data got 85
   * schannel: encrypted data buffer: offset 85 length 17408
   * schannel: decrypted data length: 37
   * schannel: decrypted data added: 37
   * schannel: decrypted data cached: offset 37 length 16384
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: decrypted data buffer: offset 37 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 37
   * schannel: decrypted data buffer: offset 0 length 16384
   < 250 Directory successfully changed.
   > EPSV
   * Connect data stream passively
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: encrypted data got 101
   * schannel: encrypted data buffer: offset 101 length 17408
   * schannel: decrypted data length: 48
   * schannel: decrypted data added: 48
   * schannel: decrypted data cached: offset 48 length 16384
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: decrypted data buffer: offset 48 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 48
   * schannel: decrypted data buffer: offset 0 length 16384
   < 229 Entering Extended Passive Mode (|||1040|).
   *   Trying my.ip.adress.here...
   * TCP_NODELAY set
   * Connecting to my.ip.adress.here (my.ip.adress.here) port 1040
   * Connected to my.ip.adress.here (my.ip.adress.here) port 21 (#0)
   > TYPE I
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: encrypted data got 85
   * schannel: encrypted data buffer: offset 85 length 17408
   * schannel: decrypted data length: 31
   * schannel: decrypted data added: 31
   * schannel: decrypted data cached: offset 31 length 16384
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: decrypted data buffer: offset 31 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 31
   * schannel: decrypted data buffer: offset 0 length 16384
   < 200 Switching to Binary mode.
   > SIZE file.png
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: encrypted data got 53
   * schannel: encrypted data buffer: offset 53 length 17408
   * schannel: decrypted data length: 11
   * schannel: decrypted data added: 11
   * schannel: decrypted data cached: offset 11 length 16384
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: decrypted data buffer: offset 11 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 11
   * schannel: decrypted data buffer: offset 0 length 16384
   < 213 84381
   > RETR file.png
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: encrypted data got 117
   * schannel: encrypted data buffer: offset 117 length 17408
   * schannel: decrypted data length: 68
   * schannel: decrypted data added: 68
   * schannel: decrypted data cached: offset 68 length 16384
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: decrypted data buffer: offset 68 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 68
   * schannel: decrypted data buffer: offset 0 length 16384
   < 150 Opening BINARY mode data connection for 001.png (84381 bytes).
   * Maxdownload = -1
   * Getting file with size: 84381
   * Doing the SSL/TLS handshake on the data stream
   * schannel: SSL/TLS connection with my.ip.adress.here port 21 (step 1/3)
   * schannel: re-using existing credential handle
   * schannel: incremented credential handle refcount = 3
   * schannel: using IP address, SNI is not supported by OS.
   * schannel: sending initial handshake data: sending 307 bytes...
   * schannel: sent initial handshake data: sent 307 bytes
   * schannel: SSL/TLS connection with my.ip.adress.here port 21 (step 2/3)
   * schannel: failed to receive handshake, need more data
   * schannel: SSL/TLS connection with my.ip.adress.here port 21 (step 2/3)
   * schannel: encrypted data got 129
   * schannel: encrypted data buffer: offset 129 length 4096
   * schannel: sending next handshake data: sending 75 bytes...
   * schannel: SSL/TLS handshake complete
   * schannel: SSL/TLS connection with my.ip.adress.here port 21 (step 3/3)
   * schannel: client wants to read 16384 bytes
   * schannel: encdata_buffer resized 17408
   * schannel: encrypted data buffer: offset 0 length 17408
   * schannel: encrypted data got 10220
   * schannel: encrypted data buffer: offset 10220 length 17408
   * schannel: failed to decrypt data, need more data
   * schannel: schannel_recv cleanup
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 10220 length 17408
   * schannel: encrypted data got 4380
   * schannel: encrypted data buffer: offset 14600 length 17408
   * schannel: failed to decrypt data, need more data
   * schannel: schannel_recv cleanup
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 14600 length 17408
   * schannel: encrypted data got 1460
   * schannel: encrypted data buffer: offset 16060 length 17408
   * schannel: decrypted data length: 15872
   * schannel: decrypted data added: 15872
   * schannel: decrypted data cached: offset 15872 length 16384
   * schannel: encrypted data length: 135
   * schannel: encrypted data cached: offset 135 length 17408
   * schannel: failed to decrypt data, need more data
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 15872
   * schannel: decrypted data buffer: offset 0 length 16384
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 135 length 17408
   * schannel: encrypted data got 16060
   * schannel: encrypted data buffer: offset 16195 length 17408
   * schannel: decrypted data length: 15872
   * schannel: decrypted data added: 15872
   * schannel: decrypted data cached: offset 15872 length 16384
   * schannel: encrypted data length: 270
   * schannel: encrypted data cached: offset 270 length 17408
   * schannel: failed to decrypt data, need more data
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 15872
   * schannel: decrypted data buffer: offset 0 length 16384
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 270 length 17408
   * schannel: encrypted data got 16060
   * schannel: encrypted data buffer: offset 16330 length 17408
   * schannel: decrypted data length: 15872
   * schannel: decrypted data added: 15872
   * schannel: decrypted data cached: offset 15872 length 16384
   * schannel: encrypted data length: 405
   * schannel: encrypted data cached: offset 405 length 17408
   * schannel: failed to decrypt data, need more data
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 15872
   * schannel: decrypted data buffer: offset 0 length 16384
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 405 length 17408
   * schannel: encrypted data got 14600
   * schannel: encrypted data buffer: offset 15005 length 17408
   * schannel: failed to decrypt data, need more data
   * schannel: schannel_recv cleanup
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 15005 length 17408
   * schannel: encrypted data got 2403
   * schannel: encrypted data buffer: offset 17408 length 17408
   * schannel: decrypted data length: 15872
   * schannel: decrypted data added: 15872
   * schannel: decrypted data cached: offset 15872 length 16384
   * schannel: encrypted data length: 1483
   * schannel: encrypted data cached: offset 1483 length 17408
   * schannel: failed to decrypt data, need more data
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 15872
   * schannel: decrypted data buffer: offset 0 length 16384
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 1483 length 17408
   * schannel: encrypted data got 15925
   * schannel: encrypted data buffer: offset 17408 length 17408
   * schannel: decrypted data length: 2048
   * schannel: decrypted data added: 2048
   * schannel: decrypted data cached: offset 2048 length 16384
   * schannel: encrypted data length: 15307
   * schannel: encrypted data cached: offset 15307 length 17408
   * schannel: failed to decrypt data, need more data
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 2048
   * schannel: decrypted data buffer: offset 0 length 16384
   * schannel: client wants to read 16384 bytes
   * schannel: encrypted data buffer: offset 15307 length 17408
   * schannel: encrypted data got 2101
   * schannel: encrypted data buffer: offset 17408 length 17408
   * schannel: decrypted data length: 16384
   * schannel: decrypted data added: 16384
   * schannel: decrypted data cached: offset 16384 length 16384
   * schannel: encrypted data length: 971
   * schannel: encrypted data cached: offset 971 length 17408
   * schannel: encrypted data buffer: offset 971 length 17408
   * schannel: decrypted data buffer: offset 16384 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 16384
   * schannel: decrypted data buffer: offset 0 length 16384
   * schannel: client wants to read 2461 bytes
   * schannel: encrypted data buffer: offset 971 length 17408
   * schannel: encrypted data got 1599
   * schannel: encrypted data buffer: offset 2570 length 17408
   * schannel: decrypted data length: 2461
   * schannel: decrypted data added: 2461
   * schannel: decrypted data cached: offset 2461 length 16384
   * schannel: encrypted data length: 53
   * schannel: encrypted data cached: offset 53 length 17408
   * schannel: encrypted data buffer: offset 53 length 17408
   * schannel: decrypted data buffer: offset 2461 length 16384
   * schannel: schannel_recv cleanup
   * schannel: decrypted data returned 2461
   * schannel: decrypted data buffer: offset 0 length 16384
   

   同样，出于显而易见的原因，我用虚拟值替换了 IP、用户名和密码。

笔记：

1. HTTPS 适用于方法 3（没有尝试使用方法 2，所以我不知道它是否有效） Curl 在我的服务器和谷歌上成功执行了 https 获取请求。
2. 我假设问题出在我的 curl 安装或我的代码上，但它可能与我的服务器有关，因为我没有另一个 ftps 服务器来测试它。我知道我可以从 Mac 上的 Curl 以及 Mac 和 Windows 上的 Filezilla 使用我的服务器进行 ftps。
3. 方法2试了3次，方法3试了2次。

如果我可以提供更多信息，请告诉我。感谢您提供的任何帮助。如果我能在一周后完成这项工作，我会很高兴...

标签： c++windowsvisual-studio-2017libcurl