Manpages - CURLOPT_REDIR_PROTOCOLS.3

CURLOPT_REDIR_PROTOCOLS - protocols allowed to redirect to

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_REDIR_PROTOCOLS, long bitmask);

Pass a long that holds a bitmask of CURLPROTO_* defines. If used, this bitmask limits what protocols libcurl may use in a transfer that it follows to in a redirect when CURLOPT_FOLLOWLOCATION(3) is enabled. This allows you to limit specific transfers to only be allowed to use a subset of protocols in redirections.

Protocols denied by CURLOPT_PROTOCOLS(3) are not overridden by this option.

By default libcurl will allow HTTP, HTTPS, FTP and FTPS on redirect (7.65.2). Older versions of libcurl allowed all protocols on redirect except several disabled for security reasons: Since 7.19.4 FILE and SCP are disabled, and since 7.40.0 SMB and SMBS are also disabled. CURLPROTO_ALL enables all protocols on redirect, including those disabled for security.

These are the available protocol defines:

  CURLPROTO_DICT
  CURLPROTO_FILE
  CURLPROTO_FTP
  CURLPROTO_FTPS
  CURLPROTO_GOPHER
  CURLPROTO_HTTP
  CURLPROTO_HTTPS
  CURLPROTO_IMAP
  CURLPROTO_IMAPS
  CURLPROTO_LDAP
  CURLPROTO_LDAPS
  CURLPROTO_POP3
  CURLPROTO_POP3S
  CURLPROTO_RTMP
  CURLPROTO_RTMPE
  CURLPROTO_RTMPS
  CURLPROTO_RTMPT
  CURLPROTO_RTMPTE
  CURLPROTO_RTMPTS
  CURLPROTO_RTSP
  CURLPROTO_SCP
  CURLPROTO_SFTP
  CURLPROTO_SMB
  CURLPROTO_SMBS
  CURLPROTO_SMTP
  CURLPROTO_SMTPS
  CURLPROTO_TELNET
  CURLPROTO_TFTP

HTTP, HTTPS, FTP and FTPS (Added in 7.65.2).

Older versions defaulted to all protocols except FILE, SCP and since 7.40.0 SMB and SMBS.

All

  curl = curl_easy_init();
  if(curl) {
    /* pass in the URL from an external source */
    curl_easy_setopt(curl, CURLOPT_URL, argv[1]);

    /* only allow redirects to HTTP and HTTPS URLs */
    curl_easy_setopt(curl, CURLOPT_REDIR_PROTOCOLS,
                     CURLPROTO_HTTP | CURLPROTO_HTTPS);

    /* Perform the request */
    curl_easy_perform(curl);
  }

Added in 7.19.4, before then it would follow all protocols.

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

*CURLOPT_PROTOCOLS*(3),