CURLOPT_SSL_OPTIONS(3)

1CURLOPT_SSL_OPTIONS(3)     curl_easy_setopt options     CURLOPT_SSL_OPTIONS(3)
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NAME

6       CURLOPT_SSL_OPTIONS - set SSL behavior options
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SYNOPSIS

9       #include <curl/curl.h>
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11       CURLcode  curl_easy_setopt(CURL *handle, CURLOPT_SSL_OPTIONS, long bit‐
12       mask);
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DESCRIPTION

15       Pass a long with a bitmask to tell libcurl about  specific  SSL  behav‐
16       iors.
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18       CURLSSLOPT_ALLOW_BEAST  tells  libcurl  to not attempt to use any work‐
19       arounds for a security flaw in the SSL3 and TLS1.0 protocols.  If  this
20       option  isn't  used or this bit is set to 0, the SSL layer libcurl uses
21       may use a work-around for this flaw although it might cause  interoper‐
22       ability problems with some (older) SSL implementations. WARNING: avoid‐
23       ing this work-around lessens the security, and by setting  this  option
24       to  1 you ask for exactly that.  This option is only supported for Dar‐
25       winSSL, NSS and OpenSSL.
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27       Added in 7.44.0:
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29       CURLSSLOPT_NO_REVOKE tells libcurl to  disable  certificate  revocation
30       checks for those SSL backends where such behavior is present. Currently
31       this option is only  supported  for  WinSSL  (the  native  Windows  SSL
32       library),  with an exception in the case of Windows' Untrusted Publish‐
33       ers blacklist which it seems can't be bypassed. This  option  may  have
34       broader  support  to  accommodate  other  SSL  backends  in the future.
35       https://curl.haxx.se/docs/ssl-compared.html
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DEFAULT

38       0
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PROTOCOLS

41       All TLS-based protocols
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EXAMPLE

44       CURL *curl = curl_easy_init();
45       if(curl) {
46         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
47         /* weaken TLS only for use with silly servers */
48         curl_easy_setopt(curl, CURLOPT_SSL_OPTIONS, CURLSSLOPT_ALLOW_BEAST |
49                          CURLSSLOPT_NO_REVOKE);
50         ret = curl_easy_perform(curl);
51         curl_easy_cleanup(curl);
52       }
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AVAILABILITY

55       Added in 7.25.0
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RETURN VALUE

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