[RFC v2 10/12] tools: Add support to generate RSI using SIRK

Luiz Augusto von Dentz
2023-03-07T22:26:07Z

From: Sathish Narasimman <sathish.narasimman@intel.com>

The patch helps to generate Resolvable set identifier adv data.
which can be used as ADV data during advertisement.
It will be used to identify the device as part of setmember for
Coordinated set identification profile.
Example:
$<path to advtest/>advtest -i "761FAE703ED681F0C50B34155B6434FB"
SIRK: 761FAE703ED681F0C50B34155B6434FB
RSI: 0x71 0xcb 0xbc 0x7e 0x01 0x84
Random: bccb71
Hash: 84017e
---
tools/advtest.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 78 insertions(+), 2 deletions(-)

diff --git a/tools/advtest.c b/tools/advtest.c
index de036e783325..9ef69ed5124a 100644
--- a/tools/advtest.c
+++ b/tools/advtest.c
@@ -13,6 +13,13 @@
#include <config.h>
#endif

+#include <stdlib.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
#include <getopt.h>

#include "lib/bluetooth.h"
@@ -32,6 +39,9 @@
"\xe1\x23\x99\xc1\xca\x9a\xc3\x31"
#define SCAN_IRK "\xfa\x73\x09\x11\x3f\x03\x37\x0f" \
"\xf4\xf9\x93\x1e\xf9\xa3\x63\xa6"
+#ifndef MIN
+#define MIN(x, y) ((x) < (y) ? (x) : (y))
+#endif

static struct mgmt *mgmt;
static uint16_t index1 = MGMT_INDEX_NONE;
@@ -43,13 +53,73 @@ static struct bt_hci *scan_dev;

static void print_rpa(const uint8_t addr[6])
{
- printf(" Address: %02x:%02x:%02x:%02x:%02x:%02x\n",
+ printf(" RSI:\t0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
addr[5], addr[4], addr[3],
addr[2], addr[1], addr[0]);
printf(" Random: %02x%02x%02x\n", addr[3], addr[4], addr[5]);
printf(" Hash: %02x%02x%02x\n", addr[0], addr[1], addr[2]);
}

+static size_t hex2bin(const char *hexstr, uint8_t *buf, size_t buflen)
+{
+ size_t i, len;
+
+ len = MIN((strlen(hexstr) / 2), buflen);
+ memset(buf, 0, len);
+
+ for (i = 0; i < len; i++)
+ if (sscanf(hexstr + (i * 2), "%02hhX", &buf[i]) != 1)
+ continue;
+
+
+ return len;
+}
+
+static bool get_random_bytes(void *buf, size_t num_bytes)
+{
+ ssize_t len;
+ int fd;
+
+ fd = open("/dev/urandom", O_RDONLY);
+ if (fd < 0)
+ return false;
+
+ len = read(fd, buf, num_bytes);
+
+ close(fd);
+
+ if (len < 0)
+ return false;
+
+ return true;
+}
+
+static void generate_rsi(char *val)
+{
+ uint8_t sirk[16], hash[3];
+ uint8_t rsi[6] = {0};
+
+ hex2bin(val, sirk, sizeof(sirk));
+
+ get_random_bytes(&rsi[3], 3);
+
+ rsi[5] &= 0x3f; /* Clear 2 msb */
+ rsi[5] |= 0x40; /* Set 2nd msb */
+
+ crypto = bt_crypto_new();
+ if (!crypto) {
+ fprintf(stderr, "Failed to open crypto interface\n");
+ mainloop_exit_failure();
+ return;
+ }
+
+ bt_crypto_ah(crypto, sirk, rsi + 3, hash);
+ memcpy(rsi, hash, 3);
+
+ print_rpa(rsi);
+}
+
+
static void scan_le_adv_report(const void *data, uint8_t size,
void *user_data)
{
@@ -351,9 +421,11 @@ static void usage(void)
printf("\tadvtest [options]\n");
printf("options:\n"
"\t-h, --help Show help options\n");
+ printf(" \t-i <128bit SIRK>, Generate RSI ADV Data\n");
}

static const struct option main_options[] = {
+ { "hash", no_argument, NULL, 'i' },
{ "version", no_argument, NULL, 'v' },
{ "help", no_argument, NULL, 'h' },
{ }
@@ -366,11 +438,15 @@ int main(int argc ,char *argv[])
for (;;) {
int opt;

- opt = getopt_long(argc, argv, "vh", main_options, NULL);
+ opt = getopt_long(argc, argv, "i:vh", main_options, NULL);
if (opt < 0)
break;

switch (opt) {
+ case 'i':
+ printf("SIRK: %s\n", optarg);
+ generate_rsi(optarg);
+ return EXIT_SUCCESS;
case 'v':
printf("%s\n", VERSION);
return EXIT_SUCCESS;
--
2.39.2