Toll Free Numbers
  • Last 5 Forum Topics
    Last post

The Web Only This Site



  • MARC

    Mailing list ARChives
    - Search by -


    Computing Dictionary

  • Text Link Ads
  • LINUX man pages
  • Linux Man Page Viewer

    The following form allows you to view linux man pages.





            #include <openssl/ssl.h>
            void SSL_CTX_set_client_cert_cb(SSL_CTX *ctx, int (*client_cert_cb)(SSL *ssl, X509 **x509, EVP_PKEY **pkey));
            int (*SSL_CTX_get_client_cert_cb(SSL_CTX *ctx))(SSL *ssl, X509 **x509, EVP_PKEY **pkey);
            int (*client_cert_cb)(SSL *ssl, X509 **x509, EVP_PKEY **pkey);


           SSL_CTX_set_client_cert_cb() sets the cclliieenntt_cceerrtt_ccbb(()) callback, that
           is called when a client certificate is requested by a server and no
           certificate was yet set for the SSL object.
           When cclliieenntt_cceerrtt_ccbb(()) is NULL, no callback function is used.
           SSL_CTX_get_client_cert_cb() returns a pointer to the currently set
           callback function.
           client_cert_cb() is the application defined callback. If it wants to
           set a certificate, a certificate/private key combination must be set
           using the x509 and pkey arguments and "1" must be returned. The
           certificate will be installed into ssl, see the NOTES and BUGS
           sections.  If no certificate should be set, "0" has to be returned and
           no certificate will be sent. A negative return value will suspend the
           handshake and the handshake function will return immediatly.
           SSL_get_error(3) will return SSL_ERROR_WANT_X509_LOOKUP to indicate,
           that the handshake was suspended. The next call to the handshake
           function will again lead to the call of client_cert_cb(). It is the job
           of the client_cert_cb() to store information about the state of the
           last call, if required to continue.


           During a handshake (or renegotiation) a server may request a
           certificate from the client. A client certificate must only be sent,
           when the server did send the request.
           When a certificate was set using the SSL_CTX_use_certificate(3) family
           of functions, it will be sent to the server. The TLS standard requires
           that only a certificate is sent, if it matches the list of acceptable
           CAs sent by the server. This constraint is violated by the default
           behavior of the OpenSSL library. Using the callback function it is
           possible to implement a proper selection routine or to allow a user
           interaction to choose the certificate to be sent.
           If a callback function is defined and no certificate was yet defined
           for the SSL object, the callback function will be called.  If the
           callback function returns a certificate, the OpenSSL library will try
           to load the private key and certificate data into the SSL object using
           the SSL_use_certificate() and SSL_use_private_key() functions.  Thus it
           will permanently install the certificate and key for this SSL object.
           It will not be reset by calling SSL_clear(3).  If the callback returns
           no certificate, the OpenSSL library will not send a certificate.
           making the concept of the callback function (to allow the choice from
           several certificates) questionable.
           Once the SSL object has been used in conjunction with the callback
           function, the certificate will be set for the SSL object and will not
           be cleared even when SSL_clear(3) is being called. It is therefore
           mandatory to destroy the SSL object using SSL_free(3) and create a new
           one to return to the previous state.


           ssl(3), SSL_CTX_use_certificate(3), SSL_CTX_add_extra_chain_cert(3),
           SSL_get_client_CA_list(3), SSL_clear(3), SSL_free(3)

    1.0.1e 2013-02-11 SSL_CTX_set_client_cert_cb(3)


  • Linux

    The Distributions


    The Software


    The News


  • Toll Free

Toll Free Numbers
Copyright © 1999 - 2016 by LinuxGuruz