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-rw-r--r--include/osmocom/gsm/gsm0808_utils.h8
-rw-r--r--include/osmocom/gsm/protocol/gsm_08_08.h10
-rw-r--r--src/gsm/gsm0808_utils.c71
-rw-r--r--src/gsm/libosmogsm.map2
-rw-r--r--tests/gsm0808/gsm0808_test.c40
5 files changed, 131 insertions, 0 deletions
diff --git a/include/osmocom/gsm/gsm0808_utils.h b/include/osmocom/gsm/gsm0808_utils.h
index 48e737d1..5bd27c76 100644
--- a/include/osmocom/gsm/gsm0808_utils.h
+++ b/include/osmocom/gsm/gsm0808_utils.h
@@ -55,3 +55,11 @@ uint8_t gsm0808_enc_channel_type(struct msgb *msg,
/* Decode Channel Type element */
int gsm0808_dec_channel_type(struct gsm0808_channel_type *ct,
const uint8_t *elem, uint8_t len);
+
+/* Encode Encryption Information element */
+uint8_t gsm0808_enc_encrypt_info(struct msgb *msg,
+ const struct gsm0808_encrypt_info *ei);
+
+/* Decode Encryption Information element */
+int gsm0808_dec_encrypt_info(struct gsm0808_encrypt_info *ei,
+ const uint8_t *elem, uint8_t len);
diff --git a/include/osmocom/gsm/protocol/gsm_08_08.h b/include/osmocom/gsm/protocol/gsm_08_08.h
index e2355f68..3939aedd 100644
--- a/include/osmocom/gsm/protocol/gsm_08_08.h
+++ b/include/osmocom/gsm/protocol/gsm_08_08.h
@@ -447,3 +447,13 @@ struct gsm0808_channel_type {
uint8_t perm_spch[CH_TYPE_PERM_SPCH_MAXLEN];
unsigned int perm_spch_len;
};
+
+/* 3GPP TS 48.008 3.2.2.10 Encryption Information */
+#define ENCRY_INFO_KEY_MAXLEN 252
+#define ENCRY_INFO_PERM_ALGO_MAXLEN 8
+struct gsm0808_encrypt_info {
+ uint8_t perm_algo[ENCRY_INFO_PERM_ALGO_MAXLEN];
+ unsigned int perm_algo_len;
+ uint8_t key[ENCRY_INFO_KEY_MAXLEN];
+ unsigned int key_len;
+};
diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c
index ef0f9431..19156050 100644
--- a/src/gsm/gsm0808_utils.c
+++ b/src/gsm/gsm0808_utils.c
@@ -33,6 +33,7 @@
#define CHANNEL_TYPE_ELEMENT_MAXLEN 11
#define CHANNEL_TYPE_ELEMENT_MINLEN 3
+#define ENCRYPT_INFO_ELEMENT_MINLEN 1
/* Encode AoIP transport address element */
uint8_t gsm0808_enc_aoip_trasp_addr(struct msgb *msg,
@@ -379,3 +380,73 @@ int gsm0808_dec_channel_type(struct gsm0808_channel_type *ct,
return (int)(elem - old_elem);
}
+
+/* Encode Encryption Information element */
+uint8_t gsm0808_enc_encrypt_info(struct msgb *msg,
+ const struct gsm0808_encrypt_info *ei)
+{
+ unsigned int i;
+ uint8_t perm_algo = 0;
+ uint8_t *ptr;
+ uint8_t *old_tail;
+ uint8_t *tlv_len;
+
+ OSMO_ASSERT(msg);
+ OSMO_ASSERT(ei);
+ OSMO_ASSERT(ei->key_len <= ARRAY_SIZE(ei->key));
+ OSMO_ASSERT(ei->perm_algo_len <= ENCRY_INFO_PERM_ALGO_MAXLEN);
+
+ msgb_put_u8(msg, GSM0808_IE_ENCRYPTION_INFORMATION);
+ tlv_len = msgb_put(msg, 1);
+ old_tail = msg->tail;
+
+ for (i = 0; i < ei->perm_algo_len; i++) {
+ /* Note: gsm_08_08.h defines the permitted algorithms
+ * as an enum which ranges from 0x01 to 0x08 */
+ OSMO_ASSERT(ei->perm_algo[i] != 0);
+ OSMO_ASSERT(ei->perm_algo[i] <= ENCRY_INFO_PERM_ALGO_MAXLEN);
+ perm_algo |= (1 << (ei->perm_algo[i] - 1));
+ }
+
+ msgb_put_u8(msg, perm_algo);
+ ptr = msgb_put(msg, ei->key_len);
+ memcpy(ptr, ei->key, ei->key_len);
+
+ *tlv_len = (uint8_t) (msg->tail - old_tail);
+ return *tlv_len + 2;
+}
+
+/* Decode Encryption Information element */
+int gsm0808_dec_encrypt_info(struct gsm0808_encrypt_info *ei,
+ const uint8_t *elem, uint8_t len)
+{
+ uint8_t perm_algo;
+ unsigned int i;
+ unsigned int perm_algo_len = 0;
+ const uint8_t *old_elem = elem;
+
+ OSMO_ASSERT(ei);
+ if (!elem)
+ return -EINVAL;
+ if (len <= 0)
+ return -EINVAL;
+
+ memset(ei, 0, sizeof(*ei));
+
+ perm_algo = *elem;
+ elem++;
+
+ for (i = 0; i < ENCRY_INFO_PERM_ALGO_MAXLEN; i++) {
+ if (perm_algo & (1 << i)) {
+ ei->perm_algo[perm_algo_len] = i + 1;
+ perm_algo_len++;
+ }
+ }
+ ei->perm_algo_len = perm_algo_len;
+
+ ei->key_len = len - 1;
+ memcpy(ei->key, elem, ei->key_len);
+ elem+=ei->key_len;
+
+ return (int)(elem - old_elem);
+}
diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map
index 2ba0c427..323ad5ad 100644
--- a/src/gsm/libosmogsm.map
+++ b/src/gsm/libosmogsm.map
@@ -148,6 +148,8 @@ gsm0808_enc_speech_codec_list;
gsm0808_dec_speech_codec_list;
gsm0808_enc_channel_type;
gsm0808_dec_channel_type;
+gsm0808_enc_encrypt_info;
+gsm0808_dec_encrypt_info;
gsm0858_rsl_ul_meas_enc;
diff --git a/tests/gsm0808/gsm0808_test.c b/tests/gsm0808/gsm0808_test.c
index 0dd9e846..5fe9c876 100644
--- a/tests/gsm0808/gsm0808_test.c
+++ b/tests/gsm0808/gsm0808_test.c
@@ -571,6 +571,45 @@ static void test_gsm0808_enc_dec_channel_type()
msgb_free(msg);
}
+static void test_gsm0808_enc_dec_encrypt_info()
+{
+ struct gsm0808_encrypt_info enc_ei;
+ struct gsm0808_encrypt_info dec_ei;
+ struct msgb *msg;
+ uint8_t ei_enc_expected[] =
+ { GSM0808_IE_ENCRYPTION_INFORMATION, 0x09, 0x03, 0xaa, 0xbb,
+ 0xcc, 0xdd, 0xee, 0xff, 0x23, 0x42
+ };
+ uint8_t rc_enc;
+ int rc_dec;
+
+ memset(&enc_ei, 0, sizeof(enc_ei));
+ enc_ei.perm_algo[0] = GSM0808_ALG_ID_A5_0;
+ enc_ei.perm_algo[1] = GSM0808_ALG_ID_A5_1;
+ enc_ei.perm_algo_len = 2;
+ enc_ei.key[0] = 0xaa;
+ enc_ei.key[1] = 0xbb;
+ enc_ei.key[2] = 0xcc;
+ enc_ei.key[3] = 0xdd;
+ enc_ei.key[4] = 0xee;
+ enc_ei.key[5] = 0xff;
+ enc_ei.key[6] = 0x23;
+ enc_ei.key[7] = 0x42;
+ enc_ei.key_len = 8;
+
+ msg = msgb_alloc(1024, "output buffer");
+ rc_enc = gsm0808_enc_encrypt_info(msg, &enc_ei);
+ OSMO_ASSERT(rc_enc == 11);
+ OSMO_ASSERT(memcmp(ei_enc_expected, msg->data, msg->len) == 0);
+
+ rc_dec = gsm0808_dec_encrypt_info(&dec_ei, msg->data + 2, msg->len - 2);
+ OSMO_ASSERT(rc_dec == 9);
+
+ OSMO_ASSERT(memcmp(&enc_ei, &dec_ei, sizeof(enc_ei)) == 0);
+
+ msgb_free(msg);
+}
+
int main(int argc, char **argv)
{
printf("Testing generation of GSM0808 messages\n");
@@ -597,6 +636,7 @@ int main(int argc, char **argv)
test_gsm0808_enc_dec_speech_codec_ext_with_cfg();
test_gsm0808_enc_dec_speech_codec_list();
test_gsm0808_enc_dec_channel_type();
+ test_gsm0808_enc_dec_encrypt_info();
printf("Done\n");
return EXIT_SUCCESS;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-25 03:16:09 +0000