2002-11-12 06:41:45 +08:00
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Peer SSL Certificate Verification
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=================================
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2003-06-27 05:30:48 +08:00
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2002-11-12 06:41:45 +08:00
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Starting in 7.10, libcurl performs peer SSL certificate verification by
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default. This is done by installing a default CA cert bundle on 'make install'
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(or similar), that CA bundle package is used by default on operations against
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SSL servers.
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2002-11-12 06:37:59 +08:00
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2003-01-23 14:09:35 +08:00
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Alas, if you communicate with HTTPS servers using certificates that are signed
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2002-11-12 06:37:59 +08:00
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by CAs present in the bundle, you will not notice any changed behavior and you
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2003-02-08 22:36:18 +08:00
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will seamlessly get a higher security level on your SSL connections since you
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can be sure that the remote server really is the one it claims to be.
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2002-11-12 06:37:59 +08:00
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If the remote server uses a self-signed certificate, or if you don't install
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curl's CA cert bundle or if it uses a certificate signed by a CA that isn't
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included in the bundle, then you need to do one of the following:
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1. Tell libcurl to *not* verify the peer. With libcurl you disable with with
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curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, FALSE);
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With the curl command tool, you disable this with -k/--insecure.
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2. Get a CA certificate that can verify the remote server and use the proper
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option to point out this CA cert for verification when connecting. For
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libcurl hackers: curl_easy_setopt(curl, CURLOPT_CAPATH, capath);
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With the curl command tool: --cacert [file]
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2003-01-23 14:15:26 +08:00
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Neglecting to use one of the above menthods when dealing with a server using a
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certficate that isn't signed by one of the certficates in the installed CA
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cert bundle, will cause SSL to report an error ("certificate verify failed")
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during the handshake and SSL will then refuse further communication with that
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server.
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This procedure has been deemed The Right Thing even though it adds this extra
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trouble for some users, since it adds security to a majority of the SSL
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connections that previously weren't really secure. It turned out many people
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were using previous versions of curl/libcurl without realizing the need for
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the CA cert options to get truly secure SSL connections.
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