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Updated: Thursday, June 13, 2019
 
 

CURLOPT_PROXY_PINNEDPUBLICKEY (3)

Name

CURLOPT_PROXY_PINNEDPUBLICKEY - set pinned public key for https proxy

Synopsis

#include <curl/curl.h>

CURLcode  curl_easy_setopt(CURL *handle, CURLOPT_PROXY_PINNEDPUBLICKEY,
char *pinnedpubkey);

Description

curl_easy_setopt options                      CURLOPT_PROXY_PINNEDPUBLICKEY(3)



NAME
       CURLOPT_PROXY_PINNEDPUBLICKEY - set pinned public key for https proxy

SYNOPSIS
       #include <curl/curl.h>

       CURLcode  curl_easy_setopt(CURL *handle, CURLOPT_PROXY_PINNEDPUBLICKEY,
       char *pinnedpubkey);

DESCRIPTION
       Pass a pointer to a zero terminated string as parameter. The string can
       be the file name of your pinned public key. The file format expected is
       "PEM" or "DER".  The string can also be any number  of  base64  encoded
       sha256 hashes preceded by "sha256//" and separated by ";"

       When  negotiating a TLS or SSL connection, the https proxy sends a cer-
       tificate indicating its identity. A public key is extracted  from  this
       certificate and if it does not exactly match the public key provided to
       this option, curl will abort the connection before sending or receiving
       any data.

       On mismatch, CURLE_SSL_PINNEDPUBKEYNOTMATCH is returned.

       The  application  does not have to keep the string around after setting
       this option.

DEFAULT
       NULL

PROTOCOLS
       All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

EXAMPLE
       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
         curl_easy_setopt(curl, CURLOPT_PROXY, "https://proxy:443");
         curl_easy_setopt(curl, CURLOPT_PROXY_PINNEDPUBLICKEY,
         "sha256//YhKJKSzoTt2b5FP18fvpHo7fJYqQCjAa3HWY3tvRMwE=;sha256//t62CeU2tQiqkexU74Gxa2eg7fRbEgoChTociMee9wno=");

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

PUBLIC KEY EXTRACTION
       If you do not have the https proxy server's public  key  file  you  can
       extract it from the https proxy server's certificate.
       # retrieve the server's certificate if you don't already have it
       #
       # be sure to examine the certificate to see if it is what you expected
       #
       # Windows-specific:
       # - Use NUL instead of /dev/null.
       # - OpenSSL may wait for input instead of disconnecting. Hit enter.
       # - If you don't have sed, then just copy the certificate into a file:
       #   Lines from -----BEGIN CERTIFICATE----- to -----END CERTIFICATE-----.
       #
       openssl s_client -servername www.example.com -connect www.example.com:443 < /dev/null | sed -n "/-----BEGIN/,/-----END/p" > www.example.com.pem

       # extract public key in pem format from certificate
       openssl x509 -in www.example.com.pem -pubkey -noout > www.example.com.pubkey.pem

       # convert public key from pem to der
       openssl asn1parse -noout -inform pem -in www.example.com.pubkey.pem -out www.example.com.pubkey.der

       # sha256 hash and base64 encode der to string for use
       openssl dgst -sha256 -binary www.example.com.pubkey.der | openssl base64
       The  public  key  in  PEM  format  contains a header, base64 data and a
       footer:
       -----BEGIN PUBLIC KEY-----
       [BASE 64 DATA]
       -----END PUBLIC KEY-----

AVAILABILITY
       PEM/DER support:

         7.52.0:  GSKit,  GnuTLS,  NSS,  OpenSSL,  PolarSSL,  mbedtls,   wolf-
       SSL/CyaSSL

       sha256 support:

         7.52.0: GnuTLS, NSS, OpenSSL, PolarSSL, mbedtls, wolfSSL/CyaSSL

       Other SSL backends not supported.

RETURN VALUE
       Returns  CURLE_OK  if  TLS  enabled,  CURLE_UNKNOWN_OPTION  if  not, or
       CURLE_OUT_OF_MEMORY if there was insufficient heap space.


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+------------------+
       |ATTRIBUTE TYPE | ATTRIBUTE VALUE  |
       +---------------+------------------+
       |Availability   | web/curl         |
       +---------------+------------------+
       |Stability      | Uncommitted      |
       +---------------+------------------+
SEE ALSO
       CURLOPT_PROXY_SSL_VERIFYPEER(3), CURLOPT_PROXY_SSL_VERIFYHOST(3),  CUR-
       LOPT_PROXY_CAINFO(3), CURLOPT_PROXY_CAPATH(3),



NOTES
       This     software     was    built    from    source    available    at
       https://github.com/oracle/solaris-userland.   The  original   community
       source    was    downloaded    from    https://github.com/curl/curl/ar-
       chive/curl-7_64_0.zip

       Further information about this software can be found on the open source
       community website at http://curl.haxx.se/.



libcurl 7.52.0                    24 Nov 2016
                                              CURLOPT_PROXY_PINNEDPUBLICKEY(3)