e3fe020089
Remove the PROTOCOLS section from the source files completely and instead generate them based on the header data in the curldown files. It also generates TLS backend information for options marked for TLS as protocol. Closes #13175
99 lines
2.9 KiB
Markdown
99 lines
2.9 KiB
Markdown
---
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c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
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SPDX-License-Identifier: curl
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Title: CURLOPT_SSL_VERIFYPEER
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Section: 3
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Source: libcurl
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See-also:
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- CURLINFO_CAINFO (3)
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- CURLINFO_CAPATH (3)
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- CURLOPT_CAINFO (3)
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- CURLOPT_PROXY_SSL_VERIFYHOST (3)
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- CURLOPT_PROXY_SSL_VERIFYPEER (3)
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- CURLOPT_SSL_VERIFYHOST (3)
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Protocol:
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- TLS
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TLS-backend:
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- All
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---
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# NAME
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CURLOPT_SSL_VERIFYPEER - verify the peer's SSL certificate
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# SYNOPSIS
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~~~c
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#include <curl/curl.h>
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CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSL_VERIFYPEER, long verify);
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~~~
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# DESCRIPTION
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Pass a long as parameter to enable or disable.
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This option determines whether curl verifies the authenticity of the peer's
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certificate. A value of 1 means curl verifies; 0 (zero) means it does not.
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When negotiating a TLS or SSL connection, the server sends a certificate
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indicating its identity. Curl verifies whether the certificate is authentic,
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i.e. that you can trust that the server is who the certificate says it is.
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This trust is based on a chain of digital signatures, rooted in certification
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authority (CA) certificates you supply. curl uses a default bundle of CA
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certificates (the path for that is determined at build time) and you can
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specify alternate certificates with the CURLOPT_CAINFO(3) option or the
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CURLOPT_CAPATH(3) option.
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When CURLOPT_SSL_VERIFYPEER(3) is enabled, and the verification fails to
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prove that the certificate is signed by a CA, the connection fails.
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When this option is disabled (set to zero), the CA certificates are not loaded
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and the peer certificate verification is simply skipped.
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Authenticating the certificate is not enough to be sure about the server. You
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typically also want to ensure that the server is the server you mean to be
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talking to. Use CURLOPT_SSL_VERIFYHOST(3) for that. The check that the host
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name in the certificate is valid for the hostname you are connecting to is
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done independently of the CURLOPT_SSL_VERIFYPEER(3) option.
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WARNING: disabling verification of the certificate allows bad guys to
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man-in-the-middle the communication without you knowing it. Disabling
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verification makes the communication insecure. Just having encryption on a
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transfer is not enough as you cannot be sure that you are communicating with
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the correct end-point.
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When libcurl uses secure protocols it trusts responses and allows for example
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HSTS and Alt-Svc information to be stored and used subsequently. Disabling
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certificate verification can make libcurl trust and use such information from
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malicious servers.
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# DEFAULT
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1 - enabled
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# EXAMPLE
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~~~c
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int main(void)
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{
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CURL *curl = curl_easy_init();
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if(curl) {
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curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
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/* Set the default value: strict certificate check please */
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curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);
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curl_easy_perform(curl);
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}
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}
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~~~
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# AVAILABILITY
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If built TLS enabled.
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# RETURN VALUE
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Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
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