osmocom
/
wireshark
14
0
Fork 1
Code Issues Pull Requests Projects Releases Wiki Activity

Don't assume we have the libgcrypt MAC functions. 

Not all the versions we support have them.

Change-Id: I7851db692a0bff0fb22ab9d40c8d5f9dc3730fef
Reviewed-on: https://code.wireshark.org/review/22108
Reviewed-by: Guy Harris <guy@alum.mit.edu>
This commit is contained in:
Guy Harris 2017-06-12 20:47:59 -07:00
parent 5fd35d115f
commit 61fda41a97
1 changed files with 14 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
epan/dissectors/packet-lorawan.c
View File

@ -425,6 +425,7 @@ static device_encryption_keys_t *get_encryption_keys_app_eui(const guint8 *appeu
return NULL;
}
#if GCRYPT_VERSION_NUMBER >= 0x010600 /* 1.6.0 */
static guint32
calculate_mic(const guint8 *in, guint8 length, const guint8 *key)
{
@ -457,6 +458,7 @@ calculate_mic(const guint8 *in, guint8 length, const guint8 *key)
gcry_mac_close(mac_hd);
return mac;
}
#endif
/* length should be a multiple of 16, in should be padded to get to a multiple of 16 */
static gboolean
@ -688,11 +690,14 @@ dissect_lorawan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree _U_, void *d
* MIC = cmac[0..3]
*/
encryption_keys = get_encryption_keys_app_eui(tvb_get_ptr(tvb, current_offset - 18, 8));
#if GCRYPT_VERSION_NUMBER >= 0x010600 /* 1.6.0 */
if (encryption_keys) {
if (calculate_mic(tvb_get_ptr(tvb, 0, current_offset), current_offset, encryption_keys->appskey->data) != tvb_get_guint32(tvb, current_offset, ENC_LITTLE_ENDIAN)) {
proto_tree_add_expert_format(lorawan_tree, pinfo, &ei_lorawan_invalid_crc, tvb, current_offset, 4, "Invalid CRC");
}
} else {
} else
#endif
{
proto_tree_add_expert_format(lorawan_tree, pinfo, &ei_lorawan_unverified_crc, tvb, current_offset, 4, "Unverified CRC");
}
proto_tree_add_item(lorawan_tree, hf_lorawan_mic_type, tvb, current_offset, 4, ENC_LITTLE_ENDIAN);
@ -720,11 +725,14 @@ dissect_lorawan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree _U_, void *d
* MIC = cmac[0..3]
*/
encryption_keys = get_encryption_keys_dev_address(dev_address);
#if GCRYPT_VERSION_NUMBER >= 0x010600 /* 1.6.0 */
if (encryption_keys) {
if (calculate_mic(tvb_get_ptr(tvb, 0, current_offset), current_offset, encryption_keys->appskey->data) != tvb_get_guint32(tvb, current_offset, ENC_LITTLE_ENDIAN)) {
proto_tree_add_expert_format(lorawan_tree, pinfo, &ei_lorawan_invalid_crc, tvb, current_offset, 4, "Invalid CRC");
}
} else {
} else
#endif
{
proto_tree_add_expert_format(lorawan_tree, pinfo, &ei_lorawan_unverified_crc, tvb, current_offset, 4, "Unverified CRC");
}
proto_tree_add_item(lorawan_tree, hf_lorawan_mic_type, tvb, current_offset, 4, ENC_LITTLE_ENDIAN);
@ -813,6 +821,7 @@ dissect_lorawan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree _U_, void *d
* B0 = 0x49 | 0x00 | 0x00 | 0x00 | 0x00 | dir | devAddr | fcntup/fcntdown | len(msg)
*/
frame_length = current_offset;
#if GCRYPT_VERSION_NUMBER >= 0x010600 /* 1.6.0 */
if (encryption_keys) {
guint8 *msg = (guint8 *)wmem_alloc0(wmem_packet_scope(), frame_length + 16);
msg[0] = 0x49;
@ -824,7 +833,9 @@ dissect_lorawan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree _U_, void *d
if (calculate_mic(msg, frame_length + 16, encryption_keys->nwkskey->data) != tvb_get_guint32(tvb, current_offset, ENC_LITTLE_ENDIAN)) {
proto_tree_add_expert_format(lorawan_tree, pinfo, &ei_lorawan_invalid_crc, tvb, current_offset, 4, "Invalid CRC");
}
} else {
} else
#endif
{
proto_tree_add_expert_format(lorawan_tree, pinfo, &ei_lorawan_unverified_crc, tvb, current_offset, 4, "Unverified CRC");
}
proto_tree_add_item(lorawan_tree, hf_lorawan_mic_type, tvb, current_offset, 4, ENC_LITTLE_ENDIAN);