/* * xfm.h * * interface for abstract crypto transform * * David A. McGrew * Cisco Systems, Inc. */ #ifndef XFM_H #define XFM_H #include "crypto_kernel.h" #include "err.h" /** * @defgroup Crypto Cryptography * * A simple interface to an abstract cryptographic transform that * provides both confidentiality and message authentication. * * @{ */ /** * @brief applies a crypto transform * * The function pointer xfm_func_t points to a function that * implements a crypto transform, and provides a uniform API for * accessing crypto mechanisms. * * @param key location of secret key * * @param clear data to be authenticated only * * @param clear_len length of data to be authenticated only * * @param iv location to write the Initialization Vector (IV) * * @param protect location of the data to be encrypted and * authenticated (before the function call), and the ciphertext * and authentication tag (after the call) * * @param protected_len location of the length of the data to be * encrypted and authenticated (before the function call), and the * length of the ciphertext (after the call) * * @param auth_tag location to write auth tag */ typedef err_status_t (*xfm_func_t) (void *key, void *clear, unsigned clear_len, void *iv, void *protect, unsigned *protected_len, void *auth_tag ); typedef err_status_t (*xfm_inv_t) (void *key, /* location of secret key */ void *clear, /* data to be authenticated only */ unsigned clear_len, /* length of data to be authenticated only */ void *iv, /* location of iv */ void *opaque, /* data to be decrypted and authenticated */ unsigned *opaque_len, /* location of the length of data to be * decrypted and authd (before and after) */ void *auth_tag /* location of auth tag */ ); typedef struct xfm_ctx_t { xfm_func_t func; xfm_inv_t inv; unsigned key_len; unsigned iv_len; unsigned auth_tag_len; } xfm_ctx_t; typedef xfm_ctx_t *xfm_t; #define xfm_get_key_len(xfm) ((xfm)->key_len) #define xfm_get_iv_len(xfm) ((xfm)->iv_len) #define xfm_get_auth_tag_len(xfm) ((xfm)->auth_tag_len) /* cryptoalgo - 5/28 */ typedef err_status_t (*cryptoalg_func_t) (void *key, void *clear, unsigned clear_len, void *iv, void *opaque, unsigned *opaque_len ); typedef err_status_t (*cryptoalg_inv_t) (void *key, /* location of secret key */ void *clear, /* data to be authenticated only */ unsigned clear_len, /* length of data to be authenticated only */ void *iv, /* location of iv */ void *opaque, /* data to be decrypted and authenticated */ unsigned *opaque_len /* location of the length of data to be * decrypted and authd (before and after) */ ); typedef struct cryptoalg_ctx_t { cryptoalg_func_t enc; cryptoalg_inv_t dec; unsigned key_len; unsigned iv_len; unsigned auth_tag_len; unsigned max_expansion; } cryptoalg_ctx_t; typedef cryptoalg_ctx_t *cryptoalg_t; #define cryptoalg_get_key_len(cryptoalg) ((cryptoalg)->key_len) #define cryptoalg_get_iv_len(cryptoalg) ((cryptoalg)->iv_len) #define cryptoalg_get_auth_tag_len(cryptoalg) ((cryptoalg)->auth_tag_len) /** * @} */ #endif /* XFM_H */
