path: root/epan/crypt/airpdcap_system.h

#ifndef	_AIRPDCAP_SYSTEM_H
#define	_AIRPDCAP_SYSTEM_H

/************************************************************************/
/*	File includes							*/

#include "airpdcap_interop.h"
#include "airpdcap_user.h"

/************************************************************************/
/*	Constant definitions						*/

/*	General definitions						*/
#ifndef	TRUE
#define	TRUE	1
#endif
#ifndef	FALSE
#define	FALSE	0
#endif

#define	AIRPDCAP_RET_SUCCESS                      0
#define	AIRPDCAP_RET_UNSUCCESS                    1

#define	AIRPDCAP_RET_NO_DATA		          1
#define	AIRPDCAP_RET_WRONG_DATA_SIZE	          2
#define	AIRPDCAP_RET_REQ_DATA		          3
#define	AIRPDCAP_RET_NO_VALID_HANDSHAKE	          4
#define	AIRPDCAP_RET_NO_DATA_ENCRYPTED	          5

#define	AIRPDCAP_RET_SUCCESS_HANDSHAKE  	 -1

#define	AIRPDCAP_MAX_KEYS_NR	        	 64
#define	AIRPDCAP_MAX_SEC_ASSOCIATIONS_NR	256

/*	Decryption algorithms fields size definition (bytes)		*/
#define	AIRPDCAP_WPA_NONCE_LEN		         32
#define	AIRPDCAP_WPA_PTK_LEN			 64	/* TKIP uses 48 bytes, CCMP uses 64 bytes	*/
#define	AIRPDCAP_WPA_MICKEY_LEN		         16

#define	AIRPDCAP_WEP_128_KEY_LEN	         16	/* 128 bits	*/

/* General 802.11 constants						*/
#define	AIRPDCAP_MAC_LEN			   6
#define	AIRPDCAP_RADIOTAP_HEADER_LEN	          24

#define	AIRPDCAP_EAPOL_MAX_LEN			1024

#define AIRPDCAP_TK_LEN                           16

/* Max length of capture data						*/
#define	AIRPDCAP_MAX_CAPLEN			8192

#define	AIRPDCAP_WEP_IVLEN	3       /* 24bit */
#define	AIRPDCAP_WEP_KIDLEN	1       /* 1 octet */
#define	AIRPDCAP_WEP_ICV	4
#define	AIRPDCAP_WEP_HEADER	AIRPDCAP_WEP_IVLEN + AIRPDCAP_WEP_KIDLEN
#define	AIRPDCAP_WEP_TRAILER	AIRPDCAP_WEP_ICV

/*
 * 802.11i defines an extended IV for use with non-WEP ciphers.
 * When the EXTIV bit is set in the key id byte an additional
 * 4 bytes immediately follow the IV for TKIP.  For CCMP the
 * EXTIV bit is likewise set but the 8 bytes represent the
 * CCMP header rather than IV+extended-IV.
 */
#define	AIRPDCAP_RSNA_EXTIV	0x20
#define	AIRPDCAP_RSNA_EXTIVLEN	4       /* extended IV length */
#define	AIRPDCAP_RSNA_MICLEN	8       /* trailing MIC */

#define	AIRPDCAP_RSNA_HEADER	AIRPDCAP_WEP_HEADER + AIRPDCAP_RSNA_EXTIVLEN

#define	AIRPDCAP_CCMP_HEADER	AIRPDCAP_RSNA_HEADER
#define	AIRPDCAP_CCMP_TRAILER	AIRPDCAP_RSNA_MICLEN

#define	AIRPDCAP_TKIP_HEADER	AIRPDCAP_RSNA_HEADER
#define	AIRPDCAP_TKIP_TRAILER	AIRPDCAP_RSNA_MICLEN + AIRPDCAP_WEP_ICV

#define	AIRPDCAP_CRC_LEN	4

/************************************************************************/
/*	Macro definitions						*/

/************************************************************************/
/*	Type definitions						*/

typedef struct _AIRPDCAP_SEC_ASSOCIATION_ID {
	UCHAR bssid[AIRPDCAP_MAC_LEN];
	UCHAR sta[AIRPDCAP_MAC_LEN];
} AIRPDCAP_SEC_ASSOCIATION_ID, *PAIRPDCAP_SEC_ASSOCIATION_ID;

typedef struct _AIRPDCAP_SEC_ASSOCIATION {
	/**
	 * This flag define whether this item is used or not. Accepted
         * values are TRUE and FALSE
	 */
	UINT8 used;
	AIRPDCAP_SEC_ASSOCIATION_ID saId;
	AIRPDCAP_KEY_ITEM *key;
	UINT8 handshake;
	UINT8 validKey;

	struct {
		UINT8 key_ver;		/* Key descriptor version	*/
		UINT64 pn;		/* only used with CCMP AES -if needed replay check- */
		UCHAR nonce[AIRPDCAP_WPA_NONCE_LEN];
		/* used to derive PTK, ANonce stored, SNonce taken	*/
		/* the 2nd packet of the 4W handshake			*/

		UCHAR ptk[AIRPDCAP_WPA_PTK_LEN];		/* session key used in decryption algorithm	*/
	} wpa;
} AIRPDCAP_SEC_ASSOCIATION, *PAIRPDCAP_SEC_ASSOCIATION;

typedef struct _AIRPDCAP_CONTEXT {
	AIRPDCAP_SEC_ASSOCIATION sa[AIRPDCAP_MAX_SEC_ASSOCIATIONS_NR];
	size_t sa_nr;
	AIRPDCAP_KEY_ITEM keys[AIRPDCAP_MAX_KEYS_NR];
	size_t keys_nr;

	INT index;
	INT first_free_index;
	INT last_stored_index;
} AIRPDCAP_CONTEXT, *PAIRPDCAP_CONTEXT;

/************************************************************************/
/*	Function prototype declarations					*/

#ifdef	__cplusplus
extern "C" {
#endif

/**
 * It processes a packet and if necessary it tries to decrypt
 * encrypted data.
 * The packet received in input should be an 802.11 frame (composed by the
 * MAC header, the frame body and the FCS -if specified-). If the data will
 * be decrypted the FCS will be recomputed. The packet received could start
 * with a RadioTap header.
 * @param ctx [IN] pointer to the current context
 * @param data [IN] pointer to a buffer with packet data
 * @param len [IN] packet data length; this should be the capture packet
 * length (to avoid errors in processing)
 * @param decrypt_data [OUT] pointer to a buffer that will contain
 * decrypted data
 * @param decrypt_len [OUT] length of decrypted data
 * @param key [OUT] pointer to a preallocated key structure containing
 * the key used during the decryption process (if done). If this parameter
 * is set to NULL, the key will be not returned.
 * @param fcsPresent [IN] flag that specifies if the FCS is present in
 * the packet or not (0 when the FCS is not present, 1 when it is).
 * @param radioTapPresent [IN] flag that specifies if a RadioTap header
 * is present or not (0 when the header is no present, 1 when it is).
 * @param mngHandshake [IN] if TRUE this function will manage the 4-way
 * handshake for WPA/WPA2
 * @param mngDecrypt [IN] if TRUE this function will manage the WEP or
 * WPA/WPA2 decryption
 * @return
 * - AIRPDCAP_RET_SUCCESS: decryption has been done (decrypt_data and
 *   decrypt_length will contain the packet data decrypted and the lenght of
 *   the new packet)
 * - AIRPDCAP_RET_SUCCESS_HANDSHAKE: a step of the 4-way handshake for
 *   WPA key has been successfully done
 * - AIRPDCAP_RET_NO_DATA: the packet is not a data packet
 * - AIRPDCAP_RET_WRONG_DATA_SIZE: the size of the packet is below the
 *   accepted minimum
 * - AIRPDCAP_RET_REQ_DATA: required data is not available and the
 *   processing must be interrupted
 * - AIRPDCAP_RET_NO_VALID_HANDSHAKE: the authentication is not for WPA or RSNA
 * - AIRPDCAP_RET_NO_DATA_ENCRYPTED: no encrypted data
 * - AIRPDCAP_RET_UNSUCCESS: no decryption has been done (decrypt_data
 *   and decrypt_length will be not modified).
 * Some other errors could be:
 *   data not correct
 *   data not encrypted
 *   key handshake, not encryption
 *   decryption not successful
 *   key handshake not correct
 *   replay check not successful
 * @note
 * The decrypted buffer should be allocated for a size equal or greater
 * than the packet data buffer size. Before decryption process original
 * data is copied in the buffer pointed by decrypt_data not to modify the
 * original packet.
 * @note
 * The length of decrypted data will consider the entire 802.11 frame
 * (thus the MAC header, the frame body and the recalculated FCS -if
 * initially present-)
 * @note
 * This function is not thread-safe when used in parallel with context
 *  management functions on the same context.
 */
extern INT AirPDcapPacketProcess(
	PAIRPDCAP_CONTEXT ctx,
	const UCHAR *data,
	const size_t len,
	UCHAR *decrypt_data,
	size_t *decrypt_len,
	PAIRPDCAP_KEY_ITEM key,
	UINT8 fcsPresent,
	UINT8 radioTapPresent,
	UINT8 mngHandshake,
	UINT8 mngDecrypt)
	;

/**
 * It sets a new keys collection to use during packet processing.
 * Any key should be well-formed, thus: it should have a defined key
 * type and the specified length should be conforming WEP or WPA/WPA2
 * standards. A general WEP keys could be of any length (in the range
 * defined in AIRPDCAP_KEY_ITEM), if a specific WEP key is used, the
 * length of the key will be the one specified in 802.11i-2004 (40 bits or
 * 104 bits).
 * For WPA/WPA2 the password (passphrase and SSID), the PSK and the PMK
 * are in alternative, as explain in the AIRPDCAP_KEY_ITEM structure
 * description.
 * @param ctx [IN] pointer to the current context
 * @param keys [IN] an array of keys to set.
 * @param keys_nr [IN] the size of the keys array
 * @return The number of keys correctly inserted in the current database.
 * @note Before inserting new keys, the current database will be cleaned.
 * @note
 * This function is not thread-safe when used in parallel with context
 * management functions and the packet process function on the same
 * context.
 */
extern INT AirPDcapSetKeys(
	PAIRPDCAP_CONTEXT ctx,
	AIRPDCAP_KEY_ITEM keys[],
	const size_t keys_nr)
	;

/**
 * Remove all keys from the active database
 * @param ctx [IN] pointer to the current context
 * @return The number of keys correctly removed.
 *
 * @note
 * This function is not thread-safe when used in parallel with context
 * management functions and the packet process function on the same
 * context.
 */
INT AirPDcapCleanKeys(
	PAIRPDCAP_CONTEXT ctx)
	;

/**
 * It gets the keys collection fom the specified context.
 * @param ctx [IN] pointer to the current context
 * @param key [IN] a preallocated array of keys to be returned
 * @param keys_nr [IN] the number of keys to return (the key array must
 * be able to contain at least keys_nr keys)
 * @return The number of keys returned
 * @note
 * Any key could be modified, as stated in the AIRPDCAP_KEY_ITEM description.
 * @note
 * This function is not thread-safe when used in parallel with context
 * management functions and the packet process function on the same
 * context.
 */
INT AirPDcapGetKeys(
	const PAIRPDCAP_CONTEXT ctx,
	AIRPDCAP_KEY_ITEM keys[],
	const size_t keys_nr)
	;
/**
 * Initialize a context used to manage decryption and keys collection.
 * @param ctx [IN|OUT] pointer to a preallocated context structure
 * @return
 *   AIRPDCAP_RET_SUCCESS: the context has been successfully initialized
 *   AIRPDCAP_RET_UNSUCCESS: the context has not been initialized
 * @note
 * Only a correctly initialized context can be used to manage decryption
 * processes and keys.
 * @note
 * This function is not thread-safe when used in parallel with context
 * management functions and the packet process function on the same context.
 */
INT AirPDcapInitContext(
        PAIRPDCAP_CONTEXT ctx)
	;

/**
 * Clean up the specified context. After the cleanup the pointer should
 * not be used anymore.
 * @param ctx [IN|OUT] pointer to the current context structure
 * @return
 *  AIRPDCAP_RET_SUCCESS: the context has been successfully initialized
 *  AIRPDCAP_RET_UNSUCCESS: the context has not been initialized
 * @note
 * This function is not thread-safe when used in parallel with context
 * management functions and the packet process function on the same
 * context.
 */
INT AirPDcapDestroyContext(
	PAIRPDCAP_CONTEXT ctx)
	;


extern INT AirPDcapWepDecrypt(
	const UCHAR *seed,
	const size_t seed_len,	/* max AIRPDCAP_KEYBUF_SIZE	*/
	UCHAR *cypher_text,
	const size_t data_len)
	;
extern INT AirPDcapCcmpDecrypt(
	UINT8 *m,
	INT len,
	UCHAR TK1[16])
	;
extern INT AirPDcapTkipDecrypt(
	UCHAR *tkip_mpdu,
	size_t mpdu_len,
	UCHAR TA[AIRPDCAP_MAC_LEN],
	UCHAR TK[AIRPDCAP_TK_LEN])
	;
extern void AirPDcapAlgHmacSha1(
	const UCHAR *key_len,
	const size_t keylen,
	UCHAR *buffer,
	const size_t digest_len,
	UCHAR digest[20])
	;


#ifdef	__cplusplus
}
#endif

#endif /* _AIRPDCAP_SYSTEM_H */