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SSL_CTX_set_cert_verify_cb(3)
NAME
  SSL_CTX_set_cert_verify_cb - Set peer certificate verification procedure

SYNOPSIS
  #include <openssl/ssl.h>

  void SSL_CTX_set_cert_verify_cb(
	  SSL_CTX *ctx,
	  int (*cb)(),
	  char *arg );

  int
	  *callback );

DESCRIPTION
  The SSL_CTX_set_cert_verify_cb() sets the verification callback function
  for ctx. SSL objects that are created from ctx inherit the setting  valid
  at the time SSL_new() is called. The arg is currently ignored.

NOTES
  Whenever a certificate is verified during a SSL/TLS handshake, a
  verification function is called. If the application does not explicitly
  specify a verification callback function, the built-in verification
  function is used. If a verification callback callback is specified via
  SSL_CTX_set_cert_verify_callback(), the supplied callback function is
  called instead.

  By setting callback to NULL, the default behavior is restored. When the
  verification must be performed, callback will be called with the argument
  callback (X509_STORE_CTX *x509_store_ctx). The arguments that can be
  specified when setting callback are currently ignored.

  Callback should return 1 to indicate verification success and 0 to indicate
  verification failure. If SSL_VERIFY_PEER is set and callback returns 0, the
  handshake will fail. As the verification procedure may allow to continue
  the connection in case of failure (by always returning 1) the verification
  result must be set in any case using the error member of x509_store_ctx, so
  that the calling application will be informed about the detailed result of
  the verification procedure. Within x509_store_ctx, callback has access to
  the verify_callback function set using SSL_CTX_set_verify()).

RESTRICTIONS
  Do not mix the verification callback described in this function with the
  verify_callback function called during the verification process. The latter
  is set using the SSL_CTX_set_verify() family of functions. Providing a
  complete verification procedure, including certificate  purpose settings,
  is a complex task. The built-in procedure is quite powerful and in most
  cases it should be sufficient to modify its behavior using the verify_cb
  function.

  It is possible to specify arguments to be passed to the verification
  callback.  However,  they are currently ignored. The callback function is
  not specified via a prototype, so that no type checking takes place.

RETURN VALUES
  The SSL_CTX_set_cert_verify_cb() function does not provide diagnostic
  information.

SEE ALSO
  SSL_CTX_set_verify(3), SSL_get_verify_result(3),
  SSL_CTX_load_verify_locations(3)

Index for Section 3

Alphabetical listing for S

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