SSL_CTX_load_verify_locations(3)

     SSL_CTX_load_verify_loc0.9.6h((20SSL_CTX_load_verify_locations(3)

     NAME
          SSL_CTX_load_verify_locations - set default locations for
          trusted CA certificates

     SYNOPSIS
           #include <openssl/ssl.h>

           int SSL_CTX_load_verify_locations(SSL_CTX *ctx, const char *CAfile,
                                             const char *CApath);

     DESCRIPTION
          SSL_CTX_load_verify_locations() specifies the locations for
          ctx, at which CA certificates for verification purposes are
          located. The certificates available via CAfile and CApath
          are trusted.

     NOTES
          If CAfile is not NULL, it points to a file of CA
          certificates in PEM format. The file can contain several CA
          certificates identified by

           -----BEGIN CERTIFICATE-----
           ... (CA certificate in base64 encoding) ...
           -----END CERTIFICATE-----

          sequences. Before, between, and after the certificates text
          is allowed which can be used e.g. for descriptions of the
          certificates.

          The CAfile is processed on execution of the
          SSL_CTX_load_verify_locations() function.

          If CApath is not NULL, it points to a directory containing
          CA certificates in PEM format. The files each contain one CA
          certificate. The files are looked up by the CA subject name
          hash value, which must hence be available.  If more than one
          CA certificate with the same name hash value exist, the
          extension must be different (e.g. 9d66eef0.0, 9d66eef0.1
          etc). The search is performed in the ordering of the
          extension number, regardless of other properties of the
          certificates.  Use the c_rehash utility to create the
          necessary links.

          The certificates in CApath are only looked up when required,
          e.g. when building the certificate chain or when actually
          performing the verification of a peer certificate.

          When looking up CA certificates, the OpenSSL library will
          first search the certificates in CAfile, then those in
          CApath. Certificate matching is done based on the subject
          name, the key identifier (if present), and the serial number
          as taken from the certificate to be verified. If these data

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          do not match, the next certificate will be tried. If a first
          certificate matching the parameters is found, the
          verification process will be performed; no other
          certificates for the same parameters will be searched in
          case of failure.

          In server mode, when requesting a client certificate, the
          server must send the list of CAs of which it will accept
          client certificates. This list is not influenced by the
          contents of CAfile or CApath and must explicitly be set
          using the SSL_CTX_set_client_CA_list(3) family of functions.

          When building its own certificate chain, an OpenSSL
          client/server will try to fill in missing certificates from
          CAfile/CApath, if the certificate chain was not explicitly
          specified (see SSL_CTX_add_extra_chain_cert(3),
          SSL_CTX_use_certificate(3).

     WARNINGS
          If several CA certificates matching the name, key
          identifier, and serial number condition are available, only
          the first one will be examined. This may lead to unexpected
          results if the same CA certificate is available with
          different expiration dates. If a "certificate expired"
          verification error occurs, no other certificate will be
          searched. Make sure to not have expired certificates mixed
          with valid ones.

     EXAMPLES
          Generate a CA certificate file with descriptive text from
          the CA certificates ca1.pem ca2.pem ca3.pem:

           #!/bin/sh
           rm CAfile.pem
           for i in ca1.pem ca2.pem ca3.pem ; do
             openssl x509 -in $i -text >> CAfile.pem
           done

          Prepare the directory /some/where/certs containing several
          CA certificates for use as CApath:

           cd /some/where/certs
           c_rehash .

     RETURN VALUES
          The following return values can occur:

          o   The operation failed because CAfile and CApath are NULL
              or the processing at one of the locations specified
              failed. Check the error stack to find out the reason.

          1   The operation succeeded.

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     SEE ALSO
          ssl(3), SSL_CTX_set_client_CA_list(3),
          SSL_get_client_CA_list(3), SSL_CTX_use_certificate(3),
          SSL_CTX_add_extra_chain_cert(3), SSL_CTX_set_cert_store(3)

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