2 Generate Broadcom CFE seeds and passwords for many popular modem/router devices
4 Copyright 2015 TJ <hacker@iam.tj>
5 Licenced on the terms of the GNU General Public Licence version 3
9 gcc -o cfe_gen_pass cfe_generate_password.c
17 ./cfe_gen_pass [options]
19 This tool can generate passwords for use with many devices that contain
20 Broadcom Common Firmware Environment (CFE) bootbase which has a debug mode
21 that is enabled using the "ATEN 1 XXXXXXXX" command, where XXXXXXXX is an
22 eight digit hexadecimal 'password'.
24 It is NOT necessary to have the device generate a 'seed' using "ATSE [MODEL-ID]"
25 because this tool can generate the seed from the device's first (base) MAC address.
27 When the device generates a seed it combines the number of seconds since 1970-01-01 00:00:00
28 with the router MAC address. Both are encoded in a single 6-byte hexadecimal
30 Each value is truncated to its 3 least significant bytes so, for example:
32 $ date +%F.%T; echo "obase=16;$(date +%s)" | bc
35 # MAC Address: EC:43:F6:46:C0:80
37 becomes F715F8 concatenated with 46C080
39 CFE> ATSE DSL-2492GNAU-B1BC
40 F715F846C080 <<<< last 3 bytes of MAC address
42 seconds since 1970-01-01 00:00:00 (2016-03-26 23:06:32)
44 *NOTE: the default seed after power-up is 000000 so no time value needs to be specifed
45 if "ATSE <model-id-string>" has not been executed on the device.
47 Access to the device's console via a serial UART port, or a network telnet/ssh session,
48 is required to enter the password.
50 So, for a device with base MAC address (reported by the CFE during boot) E.g:
52 CFE version 1.0.38-112.118 for BCM963268 (32bit,SP,BE)
54 Base MAC Address : ec:43:f6:46:c0:80
56 *** Press any key to stop auto run (1 seconds) ***
61 ./cfe_gen_pass -s ec:43:f6:46:c0:80 -p
63 MAC address: ec:43:f6:46:c0:80 Timestamp: 000000 Seed: 00000046c080 Password: 10f0a563
69 *** command status = 0
71 The tool can accept a timestamp as 8 hexadecimal characters (useful for testing the algorithm):
73 ./cfe_gen_pass -t 0FF020 -s ec:43:f6:46:c0:80 -p
75 MAC address: ec:43:f6:46:c0:80 Timestamp: 0FF020 Seed: 0FF02046c080 Password: 110f65a3
84 static const float VERSION = 1.3f;
85 static const size_t TIMESTAMP_SIZE = 8;
86 static const size_t SEED_SIZE = 12;
87 static const size_t PASSWORD_SIZE = 8;
88 static const size_t MESSAGE_SIZE = 128;
89 static const size_t MAC_ADDR_SIZE = 17;
90 static const size_t DATESTRING_SIZE = 20;
95 fprintf(stderr, "%s\n",
98 " -s 00:01:02:03:04:05 create seed from MAC address\n"
99 " -t [00000000] seconds since 1970-01-01 (defaults to NOW) \n"
100 " -p [SEED] generate password (with optional seed)\n\n"
101 " E.g. -s 01:02:03:04:05 \n"
102 " -s 01:02:03:04:05 -p\n"
108 pr_error_exit(unsigned int usage, const char *error, ...)
111 char error_message[MESSAGE_SIZE + 1];
115 va_start(args, error);
116 (void) vsnprintf(error_message, MESSAGE_SIZE + 1, error, args);
118 fprintf(stderr, "Error: %s\n", error_message);
120 if (usage) pr_usage();
125 static const unsigned int passwords[8] = {
137 generate_seed(char *mac, char *timestamp, char *seed)
139 unsigned int result = 0;
140 if (mac && strlen(mac) == MAC_ADDR_SIZE) {
142 char *mac_ptr = mac + 9;
143 size_t ts_len = strlen(timestamp);
144 if (ts_len == TIMESTAMP_SIZE) {
145 for (i = 0; i < SEED_SIZE; ++i) {
146 if (i < 6) // first half of seed is the truncated timestamp
147 seed[i] = timestamp[i+2];
148 else { // second half is the truncated MAC address
149 if (*mac_ptr == ':' || *mac_ptr == '-')
151 seed[i] = *mac_ptr++;
156 pr_error_exit(0, "Timestamp ('%s') should be %d hexadecimal characters e.g: 56F715F8", timestamp, TIMESTAMP_SIZE);
158 pr_error_exit(0, "MAC-ADDR should be %d characters, e.g: 00:01:02:03:04:05", MAC_ADDR_SIZE);
164 generate_pass(char *seed, char *password)
166 unsigned int result = 0;
168 if (seed && strlen(seed) == SEED_SIZE) {
169 unsigned int timestamp, byte, key, pass;
170 timestamp = byte = 0;
171 if(! sscanf(seed, "%06x", ×tamp))
172 pr_error_exit(1, "unable to parse seed's timestamp");
173 if (! sscanf(&seed[10], "%02x", &byte))
174 pr_error_exit(1, "unable to parse seed's MAC address");
176 pass = (passwords[key] + timestamp) ^ timestamp;
177 snprintf(password, PASSWORD_SIZE + 1, "%08x", pass);
180 pr_error_exit(0, "Seed should be %d hex characters", SEED_SIZE);
186 main(int argc, char **argv, char **env)
195 char *MAC_ADDR = NULL;
196 char timestamp[TIMESTAMP_SIZE + 1];
197 char seed[SEED_SIZE + 1];
198 char password[PASSWORD_SIZE + 1];
199 char date_string[DATESTRING_SIZE + 1];
200 unsigned int opt_seed, opt_pass, opt_ts;
203 seed[0] = password[0] = timestamp[0] = 0;
204 seed[SEED_SIZE] = password[PASSWORD_SIZE] = 0;
205 opt_seed = opt_pass = opt_ts = 0;
206 strncpy(timestamp, "00000000", TIMESTAMP_SIZE + 1);
208 for (arg = 1; arg < (unsigned) argc; ++arg) {
209 size_t arg_len = strlen(argv[arg]);
211 if (argv[arg][0] == '-') {
212 switch (argv[arg][1]) {
223 fprintf(stderr, "Version: %0.2f\n", VERSION);
225 } else if (opt_seed == 1) {
226 MAC_ADDR = argv[arg];
228 } else if (opt_pass == 1 && opt_seed == 0) {
229 if (arg_len != SEED_SIZE)
230 pr_error_exit(1, "seed length must be %d characters", SEED_SIZE);
232 strncpy(seed, argv[arg], SEED_SIZE);
234 } else if (opt_ts == 1) {
235 if (arg_len != TIMESTAMP_SIZE)
236 pr_error_exit(1, "timestamp length must be %d hexadecimal characters", TIMESTAMP_SIZE);
238 strncpy(timestamp, argv[arg], TIMESTAMP_SIZE);
242 if (! opt_seed && ! opt_pass)
244 else if (opt_seed && opt_seed != 2)
245 pr_error_exit(1, "seed requires MAC-ADDRESS");
246 else if (! opt_seed && opt_pass && opt_pass != 2)
247 pr_error_exit(1, "password on its own requires a pre-generated seed");
248 else if (opt_seed && opt_pass && opt_pass != 1)
249 pr_error_exit(1, "generating seed and password; cannot also accept pre-generated seed");
250 else if (opt_pass == 2 && opt_ts)
251 pr_error_exit(1, "seed already contains a timestamp; cannot over-ride it");
252 else if (opt_ts == 1 || opt_pass == 2) { // no timestamp provided; use NOW
255 snprintf(timestamp, TIMESTAMP_SIZE + 1, "%08lX", ts);
258 if (opt_pass == 2) { // try to figure out the correct date-time from the seed
259 // inherits the most significant 2 characters from the NOW time
260 strncpy(timestamp+2, seed, 6);
262 if (sscanf(timestamp, "%08lx", &tmp))
263 if (tmp > ts-3600 && tmp < ts+3600) // timestamps are so close they must be for the same date
267 if(opt_ts) { // ts needs to be valid to be converted to a time string
268 if(! sscanf(timestamp, "%08lx", &ts))
269 pr_error_exit(1, "converting timestamp string ('%s') to number", timestamp);
272 strftime(date_string, DATESTRING_SIZE, "%F %T", t);
275 if (! generate_seed(MAC_ADDR, timestamp, seed))
276 pr_error_exit(1, "unable to generate seed; aborting");
278 if (! generate_pass(seed, password))
279 pr_error_exit(0, "unable to generate password");
281 if (opt_seed || opt_pass)
282 printf("MAC address: %s Timestamp: %s (%s) Seed: %s Password: %s\n", MAC_ADDR, timestamp, date_string, seed, password);