X-Git-Url: https://iam.tj/gitweb/gitweb.cgi?p=cfe_generate_password.git;a=blobdiff_plain;f=cfe_generate_password.c;h=d51c0b98de6f3665423d8d227c630997c86607fe;hp=049b15bf33b52b809706af03a685d5b41161b4e8;hb=c3dc2e93a04e9c9e3b8f82b1e988cfd2aceb41df;hpb=60b7984e0a8ce92e058e602da1235016a8fc0ede diff --git a/cfe_generate_password.c b/cfe_generate_password.c index 049b15b..d51c0b9 100644 --- a/cfe_generate_password.c +++ b/cfe_generate_password.c @@ -5,7 +5,7 @@ Licenced on the terms of the GNU General Public Licence version 3 To build: - + gcc -o cfe_gen_pass cfe_generate_password.c Or: @@ -20,12 +20,32 @@ Broadcom Common Firmware Environment (CFE) bootbase which has a debug mode that is enabled using the "ATEN 1 XXXXXXXX" command, where XXXXXXXX is an eight digit hexadecimal 'password'. - + It is NOT necessary to have the device generate a 'seed' using "ATSE [MODEL-ID]" - because this tool can generate the seed from the device's first (base) MAC address - *provided* the "ATSE" command has NOT been executed since the device last booted. + because this tool can generate the seed from the device's first (base) MAC address. + + When the device generates a seed it combines the number of seconds since 1970-01-01 00:00:00 + with the router MAC address. Both are encoded in a single 6-byte hexadecimal + + Each value is truncated to its 3 least significant bytes so, for example: + + $ date +%F.%T; echo "obase=16;$(date +%s)" | bc + 2016-03-26.23:06:32 + 56F715F8 + # MAC Address: EC:43:F6:46:C0:80 + + becomes F715F8 concatenated with 46C080 + + CFE> ATSE DSL-2492GNAU-B1BC + F715F846C080 <<<< last 3 bytes of MAC address + ^^^^^^ + seconds since 1970-01-01 00:00:00 (2016-03-26 23:06:32) + + *NOTE: the default seed after power-up is 000000 so no time value needs to be specifed + if "ATSE " has not been executed on the device. - Access to the device's console via a serial UART port is required to enter the password. + Access to the device's console via a serial UART port, or a network telnet/ssh session, + is required to enter the password. So, for a device with base MAC address (reported by the CFE during boot) E.g: @@ -48,7 +68,7 @@ OK *** command status = 0 - The tool can accept a timestamp as 6 hexadecimal characters (useful for testing the algorithm): + The tool can accept a timestamp as 8 hexadecimal characters (useful for testing the algorithm): ./cfe_gen_pass -t 0FF020 -s ec:43:f6:46:c0:80 -p @@ -57,24 +77,26 @@ #include #include -#include #include #include +#include -static const float VERSION = 1.0f; -static const unsigned int TIMESTAMP_SIZE = 6; -static const unsigned int SEED_SIZE = 12; -static const unsigned int PASSWORD_SIZE = 8; -static const unsigned int MESSAGE_SIZE = 128; +static const float VERSION = 1.2f; +static const size_t TIMESTAMP_SIZE = 8; +static const size_t SEED_SIZE = 12; +static const size_t PASSWORD_SIZE = 8; +static const size_t MESSAGE_SIZE = 128; +static const size_t MAC_ADDR_SIZE = 17; +static const size_t DATESTRING_SIZE = 20; -void +static void pr_usage() { fprintf(stderr, "%s\n", "Usage:\n" " -v show version\n" " -s 00:01:02:03:04:05 create seed from MAC address\n" - " -t 000000 millisecond timestamp since boot\n" + " -t [00000000] seconds since 1970-01-01 (defaults to NOW) \n" " -p [SEED] generate password (with optional seed)\n\n" " E.g. -s 01:02:03:04:05 \n" " -s 01:02:03:04:05 -p\n" @@ -82,22 +104,22 @@ pr_usage() ); } -void +static void pr_error_exit(unsigned int usage, const char *error, ...) { va_list args; - char error_message[MESSAGE_SIZE]; + char error_message[MESSAGE_SIZE + 1]; if (!error) return; va_start(args, error); - vsnprintf(error_message, MESSAGE_SIZE, error, args); + (void) vsnprintf(error_message, MESSAGE_SIZE + 1, error, args); va_end(args); fprintf(stderr, "Error: %s\n", error_message); if (usage) pr_usage(); - exit(1); + exit(EXIT_FAILURE); } static const unsigned int passwords[8] = { @@ -111,43 +133,47 @@ static const unsigned int passwords[8] = { 0xC621E14A }; -unsigned int +static unsigned int generate_seed(char *mac, char *timestamp, char *seed) { unsigned int result = 0; - if (mac && strlen(mac) == 17) { - unsigned int i; + if (mac && strlen(mac) == MAC_ADDR_SIZE) { + size_t i; char *mac_ptr = mac + 9; size_t ts_len = strlen(timestamp); - for (i = 0; i <= SEED_SIZE; ++i) { - /* if no timestamp assume CFE get_time() returned 0 and CFE g_pw_timestamp == 0x00000000 */ - if (i < 6) - seed[i] = ts_len ? timestamp[i] : '0'; - else { - if (*mac_ptr == ':' || *mac_ptr == '-') - ++mac_ptr; - seed[i] = *mac_ptr++; + if (ts_len == TIMESTAMP_SIZE) { + for (i = 0; i < SEED_SIZE; ++i) { + if (i < 6) // first half of seed is the truncated timestamp + seed[i] = timestamp[i+2]; + else { // second half is the truncated MAC address + if (*mac_ptr == ':' || *mac_ptr == '-') + ++mac_ptr; + seed[i] = *mac_ptr++; + } } - } - result = 1; + result = 1; + } else + pr_error_exit(0, "Timestamp ('%s') should be %d hexadecimal characters e.g: 56F715F8", timestamp, TIMESTAMP_SIZE); } else - pr_error_exit(0, "MAC-ADDR should be 17 characters, e.g: 00:01:02:03:04:05"); + pr_error_exit(0, "MAC-ADDR should be %d characters, e.g: 00:01:02:03:04:05", MAC_ADDR_SIZE); return result; } -unsigned int +static unsigned int generate_pass(char *seed, char *password) { unsigned int result = 0; - if (seed && strlen(seed) == 12) { - unsigned int timestamp = 0; - unsigned byte = 0; - sscanf(seed, "%06x", ×tamp); - sscanf(&seed[10], "%02x", &byte); - unsigned int key = byte & 0x07; - unsigned int pass = (passwords[key] + timestamp) ^ timestamp; + if (seed && strlen(seed) == SEED_SIZE) { + unsigned int timestamp, byte, key, pass; + timestamp = byte = 0; + if(! sscanf(seed, "%06x", ×tamp)) + pr_error_exit(1, "unable to parse seed's timestamp"); + if (! sscanf(&seed[10], "%02x", &byte)) + pr_error_exit(1, "unable to parse seed's MAC address"); + key = byte & 0x07; + pass = (passwords[key] + timestamp) ^ timestamp; snprintf(password, PASSWORD_SIZE + 1, "%08x", pass); result = 1; } else @@ -167,17 +193,19 @@ main(int argc, char **argv, char **env) else { unsigned int arg; char *MAC_ADDR = NULL; - char *MODEL = NULL; char timestamp[TIMESTAMP_SIZE + 1]; char seed[SEED_SIZE + 1]; char password[PASSWORD_SIZE + 1]; + char date_string[DATESTRING_SIZE + 1]; unsigned int opt_seed, opt_pass, opt_ts; - seed[0] = password[0] = 0; - seed[SEED_SIZE] = password[PASSWORD_SIZE] = timestamp[TIMESTAMP_SIZE] = 0; + time_t ts = 0; + struct tm *t = NULL; + seed[0] = password[0] = timestamp[0] = 0; + seed[SEED_SIZE] = password[PASSWORD_SIZE] = 0; opt_seed = opt_pass = opt_ts = 0; - strncpy(timestamp, "000000", TIMESTAMP_SIZE); + strncpy(timestamp, "00000000", TIMESTAMP_SIZE + 1); - for (arg = 1; arg < argc; ++arg) { + for (arg = 1; arg < (unsigned) argc; ++arg) { size_t arg_len = strlen(argv[arg]); if (argv[arg][0] == '-') { @@ -200,12 +228,12 @@ main(int argc, char **argv, char **env) } else if (opt_pass == 1 && opt_seed == 0) { if (arg_len != SEED_SIZE) pr_error_exit(1, "seed length must be %d characters", SEED_SIZE); - + strncpy(seed, argv[arg], SEED_SIZE); ++opt_pass; } else if (opt_ts == 1) { if (arg_len != TIMESTAMP_SIZE) - pr_error_exit(1, "timestamp length must be %d characters", TIMESTAMP_SIZE); + pr_error_exit(1, "timestamp length must be %d hexadecimal characters", TIMESTAMP_SIZE); strncpy(timestamp, argv[arg], TIMESTAMP_SIZE); ++opt_ts; @@ -219,9 +247,29 @@ main(int argc, char **argv, char **env) pr_error_exit(1, "password on its own requires a pre-generated seed"); else if (opt_seed && opt_pass && opt_pass != 1) pr_error_exit(1, "generating seed and password; cannot also accept pre-generated seed"); - else if (opt_ts == 1) - pr_error_exit(0, "missing timestamp; assuming 000000"); + else if (opt_pass == 2 && opt_ts) + pr_error_exit(1, "seed already contains a timestamp; cannot over-ride it"); + else if (opt_ts == 1 || opt_pass == 2) { // no timestamp provided; use NOW + ts = time(NULL); + if (ts) + snprintf(timestamp, TIMESTAMP_SIZE + 1, "%08lX", ts); + } + if (opt_pass == 2) { // try to figure out the correct date-time from the seed + // inherits the most significant 2 characters from the NOW time + strncpy(timestamp+2, seed, 6); + time_t tmp; + if (sscanf(timestamp, "%08lx", &tmp)) + if (tmp > ts-3600 && tmp < ts+3600) // timestamps are so close they must be for the same date + ts = tmp; + } + + if(opt_ts) { // ts needs to be valid to be converted to a time string + if(! sscanf(timestamp, "%08lx", &ts)) + pr_error_exit(1, "converting timestamp string ('%s') to number", timestamp); + } + t = gmtime(&ts); + strftime(date_string, DATESTRING_SIZE, "%F %T", t); if (opt_seed) if (! generate_seed(MAC_ADDR, timestamp, seed)) @@ -230,7 +278,8 @@ main(int argc, char **argv, char **env) if (! generate_pass(seed, password)) pr_error_exit(0, "unable to generate password"); - printf("MAC address: %s Timestamp: %s Seed: %s Password: %s\n", MAC_ADDR, timestamp, seed, password); + if (opt_seed || opt_pass) + printf("MAC address: %s Timestamp: %s (%s) Seed: %s Password: %s\n", MAC_ADDR, timestamp, date_string, seed, password); } return result;