text: /**
   * @file sslconn.h SSL API
   * @ingroup core
   */
  
  /* purple
   *
   * Purple is the legal property of its developers, whose names are too numerous
   * to list here.  Please refer to the COPYRIGHT file distributed with this
   * source distribution.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA
   */
  #ifndef _PURPLE_SSLCONN_H_
  #define _PURPLE_SSLCONN_H_
  
  /** Possible SSL errors. */
  typedef enum
  {
  	PURPLE_SSL_HANDSHAKE_FAILED = 1,
  	PURPLE_SSL_CONNECT_FAILED = 2,
  	PURPLE_SSL_CERTIFICATE_INVALID = 3
  } PurpleSslErrorType;
  
  #include "certificate.h"
  #include "proxy.h"
  
  #define PURPLE_SSL_DEFAULT_PORT 443
  
  /** @copydoc _PurpleSslConnection */
  typedef struct _PurpleSslConnection PurpleSslConnection;
  
  typedef void (*PurpleSslInputFunction)(gpointer, PurpleSslConnection *,
  									 PurpleInputCondition);
  typedef void (*PurpleSslErrorFunction)(PurpleSslConnection *, PurpleSslErrorType,
  									 gpointer);
  
  struct _PurpleSslConnection
  {
  	/** Hostname to which the SSL connection will be made */
  	char *host;
  	/** Port to connect to */
  	int port;
  	/** Data to pass to PurpleSslConnection::connect_cb() */
  	void *connect_cb_data;
  	/** Callback triggered once the SSL handshake is complete */
  	PurpleSslInputFunction connect_cb;
  	/** Callback triggered if there is an error during connection */
  	PurpleSslErrorFunction error_cb;
  	/** Data passed to PurpleSslConnection::recv_cb() */
  	void *recv_cb_data;
  	/** User-defined callback executed when the SSL connection receives data */
  	PurpleSslInputFunction recv_cb;
  
  	/** File descriptor used to refer to the socket */
  	int fd;
  	/** Glib event source ID; used to refer to the received data callback
  	 * in the glib eventloop */
  	guint inpa;
  	/** Data related to the underlying TCP connection */
  	PurpleProxyConnectData *connect_data;
  
  	/** Internal connection data managed by the SSL backend (GnuTLS/LibNSS/whatever) */
  	void *private_data;
  
  	/** Verifier to use in authenticating the peer */
  	PurpleCertificateVerifier *verifier;
  
  	/** Handle to the account for which this connection is being made. Can be NULL. */
  	PurpleAccount *account;
  };
  
  /**
   * SSL implementation operations structure.
   *
   * Every SSL implementation must provide all of these and register it via purple_ssl_set_ops()
   * These should not be called directly! Instead, use the purple_ssl_* functions.
   */
  typedef struct
  {
  	/** Initializes the SSL system provided.
  	 *  @return @a TRUE if initialization succeeded
  	 *  @see purple_ssl_init
  	 */
  	gboolean (*init)(void);
  	/** Unloads the SSL system. Inverse of PurpleSslOps::init.
  	 *  @see purple_ssl_uninit
  	 */
  	void (*uninit)(void);
  	/** Sets up the SSL connection for a #PurpleSslConnection once
  	 *  the TCP connection has been established
  	 *  @see purple_ssl_connect
  	 */
  	void (*connectfunc)(PurpleSslConnection *gsc);
  	/** Destroys the internal data of the SSL connection provided.
  	 *  Freeing gsc itself is left to purple_ssl_close()
  	 *  @see purple_ssl_close
  	 */
  	void (*close)(PurpleSslConnection *gsc);
  	/** Reads data from a connection (like POSIX read())
  	 * @param gsc   Connection context
  	 * @param data  Pointer to buffer to drop data into
  	 * @param len   Maximum number of bytes to read
  	 * @return      Number of bytes actually written into @a data (which may be
  	 *              less than @a len), or <0 on error
  	 * @see purple_ssl_read
  	*/
  	size_t (*read)(PurpleSslConnection *gsc, void *data, size_t len);
  	/** Writes data to a connection (like POSIX send())
  	* @param gsc    Connection context
  	* @param data   Data buffer to send data from
  	* @param len    Number of bytes to send from buffer
  	* @return       The number of bytes written to @a data (may be less than
  	*               @a len) or <0 on error
  	* @see purple_ssl_write
  	*/
  	size_t (*write)(PurpleSslConnection *gsc, const void *data, size_t len);
  	/** Obtains the certificate chain provided by the peer
  	 *
  	 * @param gsc   Connection context
  	 * @return      A newly allocated list containing the certificates
  	 *              the peer provided.
  	 * @see PurpleCertificate
  	 * @todo        Decide whether the ordering of certificates in this
  	 *              list can be guaranteed.
  	 */
  	GList * (* get_peer_certificates)(PurpleSslConnection * gsc);
  
  	void (*_purple_reserved2)(void);
  	void (*_purple_reserved3)(void);
  	void (*_purple_reserved4)(void);
  } PurpleSslOps;
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /**************************************************************************/
  /** @name SSL API                                                         */
  /**************************************************************************/
  /*@{*/
  
  /**
   * Returns whether or not SSL is currently supported.
   *
   * @return @a TRUE if SSL is supported, or @a FALSE otherwise.
   */
  gboolean purple_ssl_is_supported(void);
  
  /**
   * Returns a human-readable string for an SSL error.
   *
   * @param error      Error code
   * @return Human-readable error explanation
   */
  const gchar * purple_ssl_strerror(PurpleSslErrorType error);
  
  /**
   * Makes a SSL connection to the specified host and port.  The caller
   * should keep track of the returned value and use it to cancel the
   * connection, if needed.
   *
   * @param account    The account making the connection.
   * @param host       The destination host.
   * @param port       The destination port.
   * @param func       The SSL input handler function.
   * @param error_func The SSL error handler function.  This function
   *                   should <strong>NOT</strong> call purple_ssl_close().  In
   *                   the event of an error the #PurpleSslConnection will be
   *                   destroyed for you.
   * @param data       User-defined data.
   *
   * @return The SSL connection handle.
   */
  PurpleSslConnection *purple_ssl_connect(PurpleAccount *account, const char *host,
  									int port, PurpleSslInputFunction func,
  									PurpleSslErrorFunction error_func,
  									void *data);
  
  /**
   * Makes a SSL connection to the specified host and port, using the separate
   * name to verify with the certificate.  The caller should keep track of the
   * returned value and use it to cancel the connection, if needed.
   *
   * @param account    The account making the connection.
   * @param host       The destination host.
   * @param port       The destination port.
   * @param func       The SSL input handler function.
   * @param error_func The SSL error handler function.  This function
   *                   should <strong>NOT</strong> call purple_ssl_close().  In
   *                   the event of an error the #PurpleSslConnection will be
   *                   destroyed for you.
   * @param ssl_host   The hostname of the other peer (to verify the CN)
   * @param data       User-defined data.
   *
   * @return The SSL connection handle.
   * @since 2.6.0
   */
  PurpleSslConnection *purple_ssl_connect_with_ssl_cn(PurpleAccount *account, const char *host,
  									int port, PurpleSslInputFunction func,
  									PurpleSslErrorFunction error_func,
  									const char *ssl_host,
  									void *data);
  
  #if !(defined PURPLE_DISABLE_DEPRECATED) || (defined _PURPLE_SSLCONN_C_)
  /**
   * Makes a SSL connection using an already open file descriptor.
   *
   * @deprecated Use purple_ssl_connect_with_host_fd() instead.
   *
   * @param account    The account making the connection.
   * @param fd         The file descriptor.
   * @param func       The SSL input handler function.
   * @param error_func The SSL error handler function.
   * @param data       User-defined data.
   *
   * @return The SSL connection handle.
   */
  PurpleSslConnection *purple_ssl_connect_fd(PurpleAccount *account, int fd,
  									   PurpleSslInputFunction func,
  									   PurpleSslErrorFunction error_func,
   									   void *data);
  #endif
  
  /**
   * Makes a SSL connection using an already open file descriptor.
   *
   * @param account    The account making the connection.
   * @param fd         The file descriptor.
   * @param func       The SSL input handler function.
   * @param error_func The SSL error handler function.
   * @param host       The hostname of the other peer (to verify the CN)
   * @param data       User-defined data.
   *
   * @return The SSL connection handle.
   *
   * @since 2.2.0
   */
  PurpleSslConnection *purple_ssl_connect_with_host_fd(PurpleAccount *account, int fd,
                                             PurpleSslInputFunction func,
                                             PurpleSslErrorFunction error_func,
                                             const char *host,
                                             void *data);
  
  /**
   * Adds an input watcher for the specified SSL connection.
   * Once the SSL handshake is complete, use this to watch for actual data across it.
   *
   * @param gsc   The SSL connection handle.
   * @param func  The callback function.
   * @param data  User-defined data.
   */
  void purple_ssl_input_add(PurpleSslConnection *gsc, PurpleSslInputFunction func,
  						void *data);
  
  /**
   * Closes a SSL connection.
   *
   * @param gsc The SSL connection to close.
   */
  void purple_ssl_close(PurpleSslConnection *gsc);
  
  /**
   * Reads data from an SSL connection.
   *
   * @param gsc    The SSL connection handle.
   * @param buffer The destination buffer.
   * @param len    The maximum number of bytes to read.
   *
   * @return The number of bytes read.
   */
  size_t purple_ssl_read(PurpleSslConnection *gsc, void *buffer, size_t len);
  
  /**
   * Writes data to an SSL connection.
   *
   * @param gsc    The SSL connection handle.
   * @param buffer The buffer to write.
   * @param len    The length of the data to write.
   *
   * @return The number of bytes written.
   */
  size_t purple_ssl_write(PurpleSslConnection *gsc, const void *buffer, size_t len);
  
  /**
   * Obtains the peer's presented certificates
   *
   * @param gsc    The SSL connection handle
   *
   * @return The peer certificate chain, in the order of certificate, issuer,
   *         issuer's issuer, etc. @a NULL if no certificates have been provided,
   *
   * @since 2.2.0
   */
  GList * purple_ssl_get_peer_certificates(PurpleSslConnection *gsc);
  
  /*@}*/
  
  /**************************************************************************/
  /** @name Subsystem API                                                   */
  /**************************************************************************/
  /*@{*/
  
  /**
   * Sets the current SSL operations structure.
   *
   * @param ops The SSL operations structure to assign.
   */
  void purple_ssl_set_ops(PurpleSslOps *ops);
  
  /**
   * Returns the current SSL operations structure.
   *
   * @return The SSL operations structure.
   */
  PurpleSslOps *purple_ssl_get_ops(void);
  
  /**
   * Initializes the SSL subsystem.
   */
  void purple_ssl_init(void);
  
  /**
   * Uninitializes the SSL subsystem.
   */
  void purple_ssl_uninit(void);
  
  /*@}*/
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* _PURPLE_SSLCONN_H_ */
  