curl/docs/libcurl/opts/CURLOPT_PROXY_CRLFILE.md
Daniel Stenberg eefcc1bda4
docs: introduce "curldown" for libcurl man page format
curldown is this new file format for libcurl man pages. It is markdown
inspired with differences:

- Each file has a set of leading headers with meta-data
- Supports a small subset of markdown
- Uses .md file extensions for editors/IDE/GitHub to treat them nicely
- Generates man pages very similar to the previous ones
- Generates man pages that still convert nicely to HTML on the website
- Detects and highlights mentions of curl symbols automatically (when
  their man page section is specified)

tools:

- cd2nroff: converts from curldown to nroff man page
- nroff2cd: convert an (old) nroff man page to curldown
- cdall: convert many nroff pages to curldown versions
- cd2cd: verifies and updates a curldown to latest curldown

This setup generates .3 versions of all the curldown versions at build time.

CI:

Since the documentation is now technically markdown in the eyes of many
things, the CI runs many more tests and checks on this documentation,
including proselint, link checkers and tests that make sure we capitalize the
first letter after a period...

Closes #12730
2024-01-23 00:29:02 +01:00

84 lines
2.1 KiB
Markdown

---
c: Copyright (C) Daniel Stenberg, <daniel.se>, et al.
SPDX-License-Identifier: curl
Title: CURLOPT_PROXY_CRLFILE
Section: 3
Source: libcurl
See-also:
- CURLOPT_PROXY_SSL_VERIFYHOST (3)
- CURLOPT_PROXY_SSL_VERIFYPEER (3)
- CURLOPT_SSL_VERIFYHOST (3)
- CURLOPT_SSL_VERIFYPEER (3)
---
# NAME
CURLOPT_PROXY_CRLFILE - HTTPS proxy Certificate Revocation List file
# SYNOPSIS
~~~c
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_CRLFILE, char *file);
~~~
# DESCRIPTION
This option is for connecting to an HTTPS proxy, not an HTTPS server.
Pass a char pointer to a null-terminated string naming a *file* with the
concatenation of CRL (in PEM format) to use in the certificate validation that
occurs during the SSL exchange.
When curl is built to use GnuTLS, there is no way to influence the use of CRL
passed to help in the verification process. When libcurl is built with OpenSSL
support, X509_V_FLAG_CRL_CHECK and X509_V_FLAG_CRL_CHECK_ALL are both set,
requiring CRL check against all the elements of the certificate chain if a CRL
file is passed.
This option makes sense only when used in combination with the
CURLOPT_PROXY_SSL_VERIFYPEER(3) option.
A specific error code (*CURLE_SSL_CRL_BADFILE*) is defined with the option. It
is returned when the SSL exchange fails because the CRL file cannot be loaded.
A failure in certificate verification due to a revocation information found in
the CRL does not trigger this specific error.
The application does not have to keep the string around after setting this
option.
# DEFAULT
NULL
# PROTOCOLS
Used with HTTPS proxy.
# EXAMPLE
~~~c
int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode res;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
curl_easy_setopt(curl, CURLOPT_PROXY, "https://localhost:80");
curl_easy_setopt(curl, CURLOPT_PROXY_CRLFILE, "/etc/certs/crl.pem");
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
}
~~~
# AVAILABILITY
Added in 7.52.0
# RETURN VALUE
Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or
CURLE_OUT_OF_MEMORY if there was insufficient heap space.