4 * common interface to ciphers
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49 #include "datatypes.h"
50 #include "rdbx.h" /* for xtd_seq_num_t */
51 #include "err.h" /* for error codes */
52 #include "crypto.h" /* for cipher_type_id_t */
53 #include "crypto_types.h" /* for values of cipher_type_id_t */
57 * @brief cipher_direction_t defines a particular cipher operation.
59 * A cipher_direction_t is an enum that describes a particular cipher
60 * operation, i.e. encryption or decryption. For some ciphers, this
61 * distinction does not matter, but for others, it is essential.
65 direction_encrypt
, /**< encryption (convert plaintext to ciphertext) */
66 direction_decrypt
, /**< decryption (convert ciphertext to plaintext) */
67 direction_any
/**< encryption or decryption */
71 * the cipher_pointer and cipher_type_pointer definitions are needed
72 * as cipher_t and cipher_type_t are not yet defined
75 typedef struct cipher_type_t
*cipher_type_pointer_t
;
76 typedef struct cipher_t
*cipher_pointer_t
;
79 * a cipher_alloc_func_t allocates (but does not initialize) a cipher_t
82 typedef err_status_t (*cipher_alloc_func_t
)
83 (cipher_pointer_t
*cp
, int key_len
);
86 * a cipher_init_func_t [re-]initializes a cipher_t with a given key
87 * and direction (i.e., encrypt or decrypt)
90 typedef err_status_t (*cipher_init_func_t
)
91 (void *state
, const uint8_t *key
, int key_len
, cipher_direction_t dir
);
93 /* a cipher_dealloc_func_t de-allocates a cipher_t */
95 typedef err_status_t (*cipher_dealloc_func_t
)(cipher_pointer_t cp
);
97 /* a cipher_set_segment_func_t sets the segment index of a cipher_t */
99 typedef err_status_t (*cipher_set_segment_func_t
)
100 (void *state
, xtd_seq_num_t idx
);
102 /* a cipher_encrypt_func_t encrypts data in-place */
104 typedef err_status_t (*cipher_encrypt_func_t
)
105 (void *state
, uint8_t *buffer
, unsigned int *octets_to_encrypt
);
107 /* a cipher_decrypt_func_t decrypts data in-place */
109 typedef err_status_t (*cipher_decrypt_func_t
)
110 (void *state
, uint8_t *buffer
, unsigned int *octets_to_decrypt
);
113 * a cipher_set_iv_func_t function sets the current initialization vector
116 typedef err_status_t (*cipher_set_iv_func_t
)
117 (cipher_pointer_t cp
, void *iv
);
120 * cipher_test_case_t is a (list of) key, salt, xtd_seq_num_t,
121 * plaintext, and ciphertext values that are known to be correct for a
122 * particular cipher. this data can be used to test an implementation
123 * in an on-the-fly self test of the correcness of the implementation.
124 * (see the cipher_type_self_test() function below)
127 typedef struct cipher_test_case_t
{
128 int key_length_octets
; /* octets in key */
129 uint8_t *key
; /* key */
130 uint8_t *idx
; /* packet index */
131 int plaintext_length_octets
; /* octets in plaintext */
132 uint8_t *plaintext
; /* plaintext */
133 int ciphertext_length_octets
; /* octets in plaintext */
134 uint8_t *ciphertext
; /* ciphertext */
135 struct cipher_test_case_t
*next_test_case
; /* pointer to next testcase */
136 } cipher_test_case_t
;
138 /* cipher_type_t defines the 'metadata' for a particular cipher type */
140 typedef struct cipher_type_t
{
141 cipher_alloc_func_t alloc
;
142 cipher_dealloc_func_t dealloc
;
143 cipher_init_func_t init
;
144 cipher_encrypt_func_t encrypt
;
145 cipher_encrypt_func_t decrypt
;
146 cipher_set_iv_func_t set_iv
;
149 cipher_test_case_t
*test_data
;
150 debug_module_t
*debug
;
155 * cipher_t defines an instantiation of a particular cipher, with fixed
156 * key length, key and salt values
159 typedef struct cipher_t
{
163 #ifdef FORCE_64BIT_ALIGN
168 /* some syntactic sugar on these function types */
170 #define cipher_type_alloc(ct, c, klen) ((ct)->alloc((c), (klen)))
172 #define cipher_dealloc(c) (((c)->type)->dealloc(c))
174 #define cipher_init(c, k, dir) (((c)->type)->init(((c)->state), (k), ((c)->key_len), (dir)))
176 #define cipher_encrypt(c, buf, len) \
177 (((c)->type)->encrypt(((c)->state), (buf), (len)))
179 #define cipher_decrypt(c, buf, len) \
180 (((c)->type)->decrypt(((c)->state), (buf), (len)))
182 #define cipher_set_iv(c, n) \
183 ((c) ? (((c)->type)->set_iv(((cipher_pointer_t)(c)->state), (n))) : \
184 err_status_no_such_op)
187 cipher_output(cipher_t
*c
, uint8_t *buffer
, int num_octets_to_output
);
190 /* some bookkeeping functions */
193 cipher_get_key_length(const cipher_t
*c
);
197 * cipher_type_self_test() tests a cipher against test cases provided in
198 * an array of values of key/xtd_seq_num_t/plaintext/ciphertext
199 * that is known to be good
203 cipher_type_self_test(const cipher_type_t
*ct
);
207 * cipher_type_test() tests a cipher against external test cases provided in
208 * an array of values of key/xtd_seq_num_t/plaintext/ciphertext
209 * that is known to be good
213 cipher_type_test(const cipher_type_t
*ct
, const cipher_test_case_t
*test_data
);
217 * cipher_bits_per_second(c, l, t) computes (and estimate of) the
218 * number of bits that a cipher implementation can encrypt in a second
220 * c is a cipher (which MUST be allocated and initialized already), l
221 * is the length in octets of the test data to be encrypted, and t is
222 * the number of trials
224 * if an error is encountered, then the value 0 is returned
228 cipher_bits_per_second(cipher_t
*c
, int octets_in_buffer
, int num_trials
);
230 #endif /* CIPHER_H */