/**

 * @file cipher.h Purple Cipher API

 * @ingroup core

 * @see @ref cipher-signals

 */

/* 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_CIPHER_H

#define PURPLE_CIPHER_H

#include <glib.h>

#define PURPLE_CIPHER(obj)			((PurpleCipher *)(obj))			/**< PurpleCipher typecast helper			*/

#define PURPLE_CIPHER_OPS(obj)		((PurpleCipherOps *)(obj))		/**< PurpleCipherInfo typecase helper		*/

#define PURPLE_CIPHER_CONTEXT(obj)	((PurpleCipherContext *)(obj))	/**< PurpleCipherContext typecast helper	*/

typedef struct _PurpleCipher			PurpleCipher;			/**< A handle to a PurpleCipher	*/

typedef struct _PurpleCipherOps		PurpleCipherOps;		/**< Ops for a PurpleCipher		*/

typedef struct _PurpleCipherContext	PurpleCipherContext;	/**< A context for a PurpleCipher	*/

/**

 * Modes for batch encrypters

 */

typedef enum _PurpleCipherBatchMode {

	PURPLE_CIPHER_BATCH_MODE_ECB,

	PURPLE_CIPHER_BATCH_MODE_CBC

} PurpleCipherBatchMode;

/**

 * The operation flags for a cipher

 */

typedef enum _PurpleCipherCaps {

	PURPLE_CIPHER_CAPS_SET_OPT          = 1 << 1,   /**< Set option flag	*/

	PURPLE_CIPHER_CAPS_GET_OPT          = 1 << 2,   /**< Get option flag	*/

	PURPLE_CIPHER_CAPS_INIT             = 1 << 3,   /**< Init flag			*/

	PURPLE_CIPHER_CAPS_RESET            = 1 << 4,   /**< Reset flag			*/

	PURPLE_CIPHER_CAPS_UNINIT           = 1 << 5,   /**< Uninit flag		*/

	PURPLE_CIPHER_CAPS_SET_IV           = 1 << 6,   /**< Set IV flag		*/

	PURPLE_CIPHER_CAPS_APPEND           = 1 << 7,   /**< Append flag		*/

	PURPLE_CIPHER_CAPS_DIGEST           = 1 << 8,   /**< Digest flag		*/

	PURPLE_CIPHER_CAPS_ENCRYPT          = 1 << 9,   /**< Encrypt flag		*/

	PURPLE_CIPHER_CAPS_DECRYPT          = 1 << 10,  /**< Decrypt flag		*/

	PURPLE_CIPHER_CAPS_SET_SALT         = 1 << 11,  /**< Set salt flag		*/

	PURPLE_CIPHER_CAPS_GET_SALT_SIZE    = 1 << 12,  /**< Get salt size flag	*/

	PURPLE_CIPHER_CAPS_SET_KEY          = 1 << 13,  /**< Set key flag		*/

	PURPLE_CIPHER_CAPS_GET_KEY_SIZE     = 1 << 14,  /**< Get key size flag	*/

	PURPLE_CIPHER_CAPS_SET_BATCH_MODE   = 1 << 15,  /**< Set batch mode flag */

	PURPLE_CIPHER_CAPS_GET_BATCH_MODE   = 1 << 16,  /**< Get batch mode flag */

	PURPLE_CIPHER_CAPS_GET_BLOCK_SIZE   = 1 << 17,  /**< The get block size flag */

	PURPLE_CIPHER_CAPS_SET_KEY_WITH_LEN = 1 << 18,  /**< The set key with length flag */

	PURPLE_CIPHER_CAPS_UNKNOWN          = 1 << 19   /**< Unknown			*/

} PurpleCipherCaps;

/**

 * The operations of a cipher.  Every cipher must implement one of these.

 */

struct _PurpleCipherOps {

	/** The set option function	*/

	void (*set_option)(PurpleCipherContext *context, const gchar *name, void *value);

	/** The get option function */

	void *(*get_option)(PurpleCipherContext *context, const gchar *name);

	/** The init function */

	void (*init)(PurpleCipherContext *context, void *extra);

	/** The reset function */

	void (*reset)(PurpleCipherContext *context, void *extra);

	/** The uninit function */

	void (*uninit)(PurpleCipherContext *context);

	/** The set initialization vector function */

	void (*set_iv)(PurpleCipherContext *context, guchar *iv, size_t len);

	/** The append data function */

	void (*append)(PurpleCipherContext *context, const guchar *data, size_t len);

	/** The digest function */

	gboolean (*digest)(PurpleCipherContext *context, size_t in_len, guchar digest[], size_t *out_len);

	/** The encrypt function */

	int (*encrypt)(PurpleCipherContext *context, const guchar data[], size_t len, guchar output[], size_t *outlen);

	/** The decrypt function */

	int (*decrypt)(PurpleCipherContext *context, const guchar data[], size_t len, guchar output[], size_t *outlen);

	/** The set salt function */

	void (*set_salt)(PurpleCipherContext *context, guchar *salt);

	/** The get salt size function */

	size_t (*get_salt_size)(PurpleCipherContext *context);

	/** The set key function */

	void (*set_key)(PurpleCipherContext *context, const guchar *key);

	/** The get key size function */

	size_t (*get_key_size)(PurpleCipherContext *context);

	/** The set batch mode function */

	void (*set_batch_mode)(PurpleCipherContext *context, PurpleCipherBatchMode mode);

	/** The get batch mode function */

	PurpleCipherBatchMode (*get_batch_mode)(PurpleCipherContext *context);

	/** The get block size function */

	size_t (*get_block_size)(PurpleCipherContext *context);

	/** The set key with length function */

	void (*set_key_with_len)(PurpleCipherContext *context, const guchar *key, size_t len);

};

#ifdef __cplusplus

extern "C" {

#endif /* __cplusplus */

/*****************************************************************************/

/** @name PurpleCipher API													 */

/*****************************************************************************/

/*@{*/

/**

 * Gets a cipher's name

 *

 * @param cipher The cipher handle

 *

 * @return The cipher's name

 */

const gchar *purple_cipher_get_name(PurpleCipher *cipher);

/**

 * Gets a cipher's capabilities

 *

 * @param cipher The cipher handle

 *

 * @return The cipher's info

 */

guint purple_cipher_get_capabilities(PurpleCipher *cipher);

/**

 * Gets a digest from a cipher

 *

 * @param name     The cipher's name

 * @param data     The data to hash

 * @param data_len The length of the data

 * @param in_len   The length of the buffer

 * @param digest   The returned digest

 * @param out_len  The length written

 *

 * @return @c TRUE if successful, @c FALSE otherwise

 */

gboolean purple_cipher_digest_region(const gchar *name, const guchar *data, size_t data_len, size_t in_len, guchar digest[], size_t *out_len);

/*@}*/

/******************************************************************************/

/** @name PurpleCiphers API													  */

/******************************************************************************/

/*@{*/

/**

 * Finds a cipher by it's name

 *

 * @param name The name of the cipher to find

 *

 * @return The cipher handle or @c NULL

 */

PurpleCipher *purple_ciphers_find_cipher(const gchar *name);

/**

 * Registers a cipher as a usable cipher

 *

 * @param name The name of the new cipher

 * @param ops  The cipher ops to register

 *

 * @return The handle to the new cipher or @c NULL if it failed

 */

PurpleCipher *purple_ciphers_register_cipher(const gchar *name, PurpleCipherOps *ops);

/**

 * Unregisters a cipher

 *

 * @param cipher The cipher handle to unregister

 *

 * @return Whether or not the cipher was successfully unloaded

 */

gboolean purple_ciphers_unregister_cipher(PurpleCipher *cipher);

/**

 * Gets the list of ciphers

 *

 * @return The list of available ciphers

 * @note This list should not be modified, it is owned by the cipher core

 */

GList *purple_ciphers_get_ciphers(void);

/*@}*/

/******************************************************************************/

/** @name PurpleCipher Subsystem API											  */

/******************************************************************************/

/*@{*/

/**

 * Gets the handle to the cipher subsystem

 *

 * @return The handle to the cipher subsystem

 */

gpointer purple_ciphers_get_handle(void);

/**

 * Initializes the cipher core

 */

void purple_ciphers_init(void);

/**

 * Uninitializes the cipher core

 */

void purple_ciphers_uninit(void);

/*@}*/

/******************************************************************************/

/** @name PurpleCipherContext API												  */

/******************************************************************************/

/*@{*/

/**

 * Sets the value an option on a cipher context

 *

 * @param context The cipher context

 * @param name    The name of the option

 * @param value   The value to set

 */

void purple_cipher_context_set_option(PurpleCipherContext *context, const gchar *name, gpointer value);

/**

 * Gets the vale of an option on a cipher context

 *

 * @param context The cipher context

 * @param name    The name of the option

 * @return The value of the option

 */

gpointer purple_cipher_context_get_option(PurpleCipherContext *context, const gchar *name);

/**

 * Creates a new cipher context and initializes it

 *

 * @param cipher The cipher to use

 * @param extra  Extra data for the specific cipher

 *

 * @return The new cipher context

 */

PurpleCipherContext *purple_cipher_context_new(PurpleCipher *cipher, void *extra);

/**

 * Creates a new cipher context by the cipher name and initializes it

 *

 * @param name  The cipher's name

 * @param extra Extra data for the specific cipher

 *

 * @return The new cipher context

 */

PurpleCipherContext *purple_cipher_context_new_by_name(const gchar *name, void *extra);

/**

 * Resets a cipher context to it's default value

 * @note If you have set an IV you will have to set it after resetting

 *

 * @param context The context to reset

 * @param extra   Extra data for the specific cipher

 */

void purple_cipher_context_reset(PurpleCipherContext *context, gpointer extra);

/**

 * Destorys a cipher context and deinitializes it

 *

 * @param context The cipher context to destory

 */

void purple_cipher_context_destroy(PurpleCipherContext *context);

/**

 * Sets the initialization vector for a context

 * @note This should only be called right after a cipher context is created or reset

 *

 * @param context The context to set the IV to

 * @param iv      The initialization vector to set

 * @param len     The len of the IV

 */

void purple_cipher_context_set_iv(PurpleCipherContext *context, guchar *iv, size_t len);

/**

 * Appends data to the context

 *

 * @param context The context to append data to

 * @param data    The data to append

 * @param len     The length of the data

 */

void purple_cipher_context_append(PurpleCipherContext *context, const guchar *data, size_t len);

/**

 * Digests a context

 *

 * @param context The context to digest

 * @param in_len  The length of the buffer

 * @param digest  The return buffer for the digest

 * @param out_len The length of the returned value

 */

gboolean purple_cipher_context_digest(PurpleCipherContext *context, size_t in_len, guchar digest[], size_t *out_len);

/**

 * Converts a guchar digest into a hex string

 *

 * @param context  The context to get a digest from

 * @param in_len   The length of the buffer

 * @param digest_s The return buffer for the string digest

 * @param out_len  The length of the returned value

 */

gboolean purple_cipher_context_digest_to_str(PurpleCipherContext *context, size_t in_len, gchar digest_s[], size_t *out_len);

/**

 * Encrypts data using the context

 *

 * @param context The context

 * @param data    The data to encrypt

 * @param len     The length of the data

 * @param output  The output buffer

 * @param outlen  The len of data that was outputed

 *

 * @return A cipher specific status code

 */

gint purple_cipher_context_encrypt(PurpleCipherContext *context, const guchar data[], size_t len, guchar output[], size_t *outlen);

/**

 * Decrypts data using the context

 *

 * @param context The context

 * @param data    The data to encrypt

 * @param len     The length of the returned value

 * @param output  The output buffer

 * @param outlen  The len of data that was outputed

 *

 * @return A cipher specific status code

 */

gint purple_cipher_context_decrypt(PurpleCipherContext *context, const guchar data[], size_t len, guchar output[], size_t *outlen);

/**

 * Sets the salt on a context

 *

 * @param context The context whose salt to set

 * @param salt    The salt

 */

void purple_cipher_context_set_salt(PurpleCipherContext *context, guchar *salt);

/**

 * Gets the size of the salt if the cipher supports it

 *

 * @param context The context whose salt size to get

 *

 * @return The size of the salt

 */

size_t purple_cipher_context_get_salt_size(PurpleCipherContext *context);

/**

 * Sets the key on a context

 *

 * @param context The context whose key to set

 * @param key     The key

 */

void purple_cipher_context_set_key(PurpleCipherContext *context, const guchar *key);

/**

 * Gets the key size for a context

 *

 * @param context The context whose key size to get

 *

 * @return The size of the key

 */

size_t purple_cipher_context_get_key_size(PurpleCipherContext *context);

/**

 * Sets the batch mode of a context

 *

 * @param context The context whose batch mode to set

 * @param mode    The batch mode under which the cipher should operate

 *

 */

void purple_cipher_context_set_batch_mode(PurpleCipherContext *context, PurpleCipherBatchMode mode);

/**

 * Gets the batch mode of a context

 *

 * @param context The context whose batch mode to get

 *

 * @return The batch mode under which the cipher is operating

 */

PurpleCipherBatchMode purple_cipher_context_get_batch_mode(PurpleCipherContext *context);

/**

 * Gets the block size of a context

 *

 * @param context The context whose block size to get

 *

 * @return The block size of the context

 */

size_t purple_cipher_context_get_block_size(PurpleCipherContext *context);

/**

 * Sets the key with a given length on a context

 *

 * @param context The context whose key to set

 * @param key     The key

 * @param len     The length of the key

 *

 */

void purple_cipher_context_set_key_with_len(PurpleCipherContext *context, const guchar *key, size_t len);

/**

 * Sets the cipher data for a context

 *

 * @param context The context whose cipher data to set

 * @param data    The cipher data to set

 */

void purple_cipher_context_set_data(PurpleCipherContext *context, gpointer data);

/**

 * Gets the cipher data for a context

 *

 * @param context The context whose cipher data to get

 *

 * @return The cipher data

 */

gpointer purple_cipher_context_get_data(PurpleCipherContext *context);

/*@}*/

/*****************************************************************************/

/** @name Purple Cipher HTTP Digest Helper Functions							 */

/*****************************************************************************/

/*@{*/

/**

 * Calculates a session key for HTTP Digest authentation

 *

 * See RFC 2617 for more information.

 *

 * @param algorithm    The hash algorithm to use

 * @param username     The username provided by the user

 * @param realm        The authentication realm provided by the server

 * @param password     The password provided by the user

 * @param nonce        The nonce provided by the server

 * @param client_nonce The nonce provided by the client

 *

 * @return The session key, or @c NULL if an error occurred.

 */

gchar *purple_cipher_http_digest_calculate_session_key(

		const gchar *algorithm, const gchar *username,

		const gchar *realm, const gchar *password,

		const gchar *nonce, const gchar *client_nonce);

/** Calculate a response for HTTP Digest authentication

 *

 * See RFC 2617 for more information.

 *

 * @param algorithm         The hash algorithm to use

 * @param method            The HTTP method in use

 * @param digest_uri        The URI from the initial request

 * @param qop               The "quality of protection"

 * @param entity            The entity body

 * @param nonce             The nonce provided by the server

 * @param nonce_count       The nonce count

 * @param client_nonce      The nonce provided by the client

 * @param session_key       The session key from purple_cipher_http_digest_calculate_session_key()

 *

 * @return The hashed response, or @c NULL if an error occurred.

 */

gchar *purple_cipher_http_digest_calculate_response(

		const gchar *algorithm, const gchar *method,

		const gchar *digest_uri, const gchar *qop,

		const gchar *entity, const gchar *nonce,

		const gchar *nonce_count, const gchar *client_nonce,

		const gchar *session_key);

/*@}*/

#ifdef __cplusplus

}

#endif /* __cplusplus */

#endif /* PURPLE_CIPHER_H */