@@ -1 +1,2 @@
-#library what description / commit summary line
+#library what description / commit summary line
+libosmogsm internal API update Internal API for GPRS cipher implementors updated to accommodate for arbitrary key lengths
\ No newline at end of file
@@ -9,6 +9,7 @@ enum gprs_ciph_algo {
GPRS_ALGO_GEA1,
GPRS_ALGO_GEA2,
GPRS_ALGO_GEA3,
+ GPRS_ALGO_GEA4,
_GPRS_ALGO_NUM
};
@@ -27,7 +28,7 @@ struct gprs_cipher_impl {
/* As specified in 04.64 Annex A. Uses Kc, IV and direction
* to generate the 1523 bytes cipher stream that need to be
* XORed wit the plaintext for encrypt / ciphertext for decrypt */
- int (*run)(uint8_t *out, uint16_t len, uint64_t kc, uint32_t iv,
+ int (*run)(uint8_t *out, uint16_t len, uint8_t *kc, uint32_t iv,
enum gprs_cipher_direction direction);
};
@@ -39,11 +40,14 @@ int gprs_cipher_load(const char *path);
/* function to be called by core code */
int gprs_cipher_run(uint8_t *out, uint16_t len, enum gprs_ciph_algo algo,
- uint64_t kc, uint32_t iv, enum gprs_cipher_direction dir);
+ uint8_t *kc, uint32_t iv, enum gprs_cipher_direction dir);
/* Do we have an implementation for this cipher? */
int gprs_cipher_supported(enum gprs_ciph_algo algo);
+/* Return key length for supported cipher, in bytes */
+unsigned gprs_cipher_key_length(enum gprs_ciph_algo algo);
+
/* GSM TS 04.64 / Section A.2.1 : Generation of 'input' */
uint32_t gprs_cipher_gen_input_ui(uint32_t iov_ui, uint8_t sapi, uint32_t lfn, uint32_t oc);
@@ -53,12 +53,14 @@ int gprs_cipher_register(struct gprs_cipher_impl *ciph)
int gprs_cipher_load(const char *path)
{
/* load all plugins available from path */
- return osmo_plugin_load_all(path);
+ if (path)
+ return osmo_plugin_load_all(path);
+ return 0;
}
/* function to be called by core code */
int gprs_cipher_run(uint8_t *out, uint16_t len, enum gprs_ciph_algo algo,
- uint64_t kc, uint32_t iv, enum gprs_cipher_direction dir)
+ uint8_t *kc, uint32_t iv, enum gprs_cipher_direction dir)
{
if (algo >= ARRAY_SIZE(selected_ciphers))
return -ERANGE;
@@ -73,6 +75,23 @@ int gprs_cipher_run(uint8_t *out, uint16_t len, enum gprs_ciph_algo algo,
return selected_ciphers[algo]->run(out, len, kc, iv, dir);
}
+/*! \brief Obtain key lenght for given GPRS cipher
+ * \param[in] algo Enum representive GPRS cipher
+ * \returns unsigned integer key length for supported algorithms,
+ * for GEA0 and unknown ciphers will return 0
+ */
+unsigned gprs_cipher_key_length(enum gprs_ciph_algo algo)
+{
+ switch (algo) {
+ case GPRS_ALGO_GEA0: return 0;
+ case GPRS_ALGO_GEA1:
+ case GPRS_ALGO_GEA2:
+ case GPRS_ALGO_GEA3: return 8;
+ case GPRS_ALGO_GEA4: return 16;
+ default: return 0;
+ }
+}
+
int gprs_cipher_supported(enum gprs_ciph_algo algo)
{
if (algo >= ARRAY_SIZE(selected_ciphers))
@@ -32,6 +32,7 @@ gprs_cipher_load;
gprs_cipher_register;
gprs_cipher_run;
gprs_cipher_supported;
+gprs_cipher_key_length;
gprs_tlli_type;
gprs_tmsi2tlli;
Signed-off-by: Max Suraev <Max.Suraev@fairwaves.co> --- TODO-RELEASE | 3 ++- include/osmocom/crypt/gprs_cipher.h | 8 ++++++-- src/gsm/gprs_cipher_core.c | 23 +++++++++++++++++++++-- src/gsm/libosmogsm.map | 1 + 4 files changed, 30 insertions(+), 5 deletions(-)