1 // SPDX-License-Identifier: GPL-2.0+
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
17 #include <u-boot/sha256.h>
18 #include <bootcount.h>
20 DECLARE_GLOBAL_DATA_PTR;
22 #define MAX_DELAY_STOP_STR 32
24 #ifndef DEBUG_BOOTKEYS
25 #define DEBUG_BOOTKEYS 0
27 #define debug_bootkeys(fmt, args...) \
28 debug_cond(DEBUG_BOOTKEYS, fmt, ##args)
30 /* Stored value of bootdelay, used by autoboot_command() */
31 static int stored_bootdelay;
34 #ifdef CONFIG_AUTOBOOT_ENCRYPTION
35 #define AUTOBOOT_STOP_STR_SHA256 CONFIG_AUTOBOOT_STOP_STR_SHA256
37 #define AUTOBOOT_STOP_STR_SHA256 ""
40 #ifdef CONFIG_USE_AUTOBOOT_MENUKEY
41 #define AUTOBOOT_MENUKEY CONFIG_USE_AUTOBOOT_MENUKEY
43 #define AUTOBOOT_MENUKEY 0
47 * Use a "constant-length" time compare function for this
50 * https://crackstation.net/hashing-security.htm
52 static int slow_equals(u8 *a, u8 *b, int len)
57 for (i = 0; i < len; i++)
64 * passwd_abort_sha256() - check for a hashed key sequence to abort booting
66 * This checks for the user entering a SHA256 hash within a given time.
68 * @etime: Timeout value ticks (stop when get_ticks() reachs this)
69 * @return 0 if autoboot should continue, 1 if it should stop
71 static int passwd_abort_sha256(uint64_t etime)
73 const char *sha_env_str = env_get("bootstopkeysha256");
74 u8 sha_env[SHA256_SUM_LEN];
77 const char *algo_name = "sha256";
78 u_int presskey_len = 0;
80 int size = sizeof(sha);
83 if (sha_env_str == NULL)
84 sha_env_str = AUTOBOOT_STOP_STR_SHA256;
87 * Generate the binary value from the environment hash value
88 * so that we can compare this value with the computed hash
91 ret = hash_parse_string(algo_name, sha_env_str, sha_env);
93 printf("Hash %s not supported!\n", algo_name);
97 presskey = malloc_cache_aligned(MAX_DELAY_STOP_STR);
98 sha = malloc_cache_aligned(SHA256_SUM_LEN);
99 size = SHA256_SUM_LEN;
101 * We don't know how long the stop-string is, so we need to
102 * generate the sha256 hash upon each input character and
103 * compare the value with the one saved in the environment
107 /* Check for input string overflow */
108 if (presskey_len >= MAX_DELAY_STOP_STR) {
114 presskey[presskey_len++] = getc();
116 /* Calculate sha256 upon each new char */
117 hash_block(algo_name, (const void *)presskey,
118 presskey_len, sha, &size);
120 /* And check if sha matches saved value in env */
121 if (slow_equals(sha, sha_env, SHA256_SUM_LEN))
124 } while (!abort && get_ticks() <= etime);
132 * passwd_abort_key() - check for a key sequence to aborted booting
134 * This checks for the user entering a string within a given time.
136 * @etime: Timeout value ticks (stop when get_ticks() reachs this)
137 * @return 0 if autoboot should continue, 1 if it should stop
139 static int passwd_abort_key(uint64_t etime)
148 { .str = env_get("bootdelaykey"), .retry = 1 },
149 { .str = env_get("bootstopkey"), .retry = 0 },
152 char presskey[MAX_DELAY_STOP_STR];
153 u_int presskey_len = 0;
154 u_int presskey_max = 0;
157 # ifdef CONFIG_AUTOBOOT_DELAY_STR
158 if (delaykey[0].str == NULL)
159 delaykey[0].str = CONFIG_AUTOBOOT_DELAY_STR;
161 # ifdef CONFIG_AUTOBOOT_STOP_STR
162 if (delaykey[1].str == NULL)
163 delaykey[1].str = CONFIG_AUTOBOOT_STOP_STR;
166 for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
167 delaykey[i].len = delaykey[i].str == NULL ?
168 0 : strlen(delaykey[i].str);
169 delaykey[i].len = delaykey[i].len > MAX_DELAY_STOP_STR ?
170 MAX_DELAY_STOP_STR : delaykey[i].len;
172 presskey_max = presskey_max > delaykey[i].len ?
173 presskey_max : delaykey[i].len;
175 debug_bootkeys("%s key:<%s>\n",
176 delaykey[i].retry ? "delay" : "stop",
177 delaykey[i].str ? delaykey[i].str : "NULL");
180 /* In order to keep up with incoming data, check timeout only
185 if (presskey_len < presskey_max) {
186 presskey[presskey_len++] = getc();
188 for (i = 0; i < presskey_max - 1; i++)
189 presskey[i] = presskey[i + 1];
191 presskey[i] = getc();
195 for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
196 if (delaykey[i].len > 0 &&
197 presskey_len >= delaykey[i].len &&
198 memcmp(presskey + presskey_len -
199 delaykey[i].len, delaykey[i].str,
200 delaykey[i].len) == 0) {
201 debug_bootkeys("got %skey\n",
202 delaykey[i].retry ? "delay" :
205 /* don't retry auto boot */
206 if (!delaykey[i].retry)
207 bootretry_dont_retry();
211 } while (!abort && get_ticks() <= etime);
216 /***************************************************************************
217 * Watch for 'delay' seconds for autoboot stop or autoboot delay string.
218 * returns: 0 - no key string, allow autoboot 1 - got key string, abort
220 static int abortboot_key_sequence(int bootdelay)
223 uint64_t etime = endtick(bootdelay);
225 # ifdef CONFIG_AUTOBOOT_PROMPT
227 * CONFIG_AUTOBOOT_PROMPT includes the %d for all boards.
228 * To print the bootdelay value upon bootup.
230 printf(CONFIG_AUTOBOOT_PROMPT, bootdelay);
233 if (IS_ENABLED(CONFIG_AUTOBOOT_ENCRYPTION))
234 abort = passwd_abort_sha256(etime);
236 abort = passwd_abort_key(etime);
238 debug_bootkeys("key timeout\n");
243 static int abortboot_single_key(int bootdelay)
248 printf("Hit any key to stop autoboot: %2d ", bootdelay);
251 * Check if key already pressed
253 if (tstc()) { /* we got a key press */
254 (void) getc(); /* consume input */
256 abort = 1; /* don't auto boot */
259 while ((bootdelay > 0) && (!abort)) {
264 if (tstc()) { /* we got a key press */
267 abort = 1; /* don't auto boot */
268 bootdelay = 0; /* no more delay */
269 key = getc(); /* consume input */
270 if (IS_ENABLED(CONFIG_USE_AUTOBOOT_MENUKEY))
275 } while (!abort && get_timer(ts) < 1000);
277 printf("\b\b\b%2d ", bootdelay);
285 static int abortboot(int bootdelay)
289 if (bootdelay >= 0) {
290 if (IS_ENABLED(CONFIG_AUTOBOOT_KEYED))
291 abort = abortboot_key_sequence(bootdelay);
293 abort = abortboot_single_key(bootdelay);
296 if (IS_ENABLED(CONFIG_SILENT_CONSOLE) && abort)
297 gd->flags &= ~GD_FLG_SILENT;
302 static void process_fdt_options(const void *blob)
304 #ifdef CONFIG_SYS_TEXT_BASE
307 /* Add an env variable to point to a kernel payload, if available */
308 addr = fdtdec_get_config_int(gd->fdt_blob, "kernel-offset", 0);
310 env_set_addr("kernaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
312 /* Add an env variable to point to a root disk, if available */
313 addr = fdtdec_get_config_int(gd->fdt_blob, "rootdisk-offset", 0);
315 env_set_addr("rootaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
316 #endif /* CONFIG_SYS_TEXT_BASE */
319 const char *bootdelay_process(void)
326 s = env_get("bootdelay");
327 bootdelay = s ? (int)simple_strtol(s, NULL, 10) : CONFIG_BOOTDELAY;
329 if (IS_ENABLED(CONFIG_OF_CONTROL))
330 bootdelay = fdtdec_get_config_int(gd->fdt_blob, "bootdelay",
333 debug("### main_loop entered: bootdelay=%d\n\n", bootdelay);
335 if (IS_ENABLED(CONFIG_AUTOBOOT_MENU_SHOW))
336 bootdelay = menu_show(bootdelay);
337 bootretry_init_cmd_timeout();
340 if (gd->flags & GD_FLG_POSTFAIL) {
341 s = env_get("failbootcmd");
343 #endif /* CONFIG_POST */
344 if (bootcount_error())
345 s = env_get("altbootcmd");
347 s = env_get("bootcmd");
349 if (IS_ENABLED(CONFIG_OF_CONTROL))
350 process_fdt_options(gd->fdt_blob);
351 stored_bootdelay = bootdelay;
356 void autoboot_command(const char *s)
358 debug("### main_loop: bootcmd=\"%s\"\n", s ? s : "<UNDEFINED>");
360 if (stored_bootdelay != -1 && s && !abortboot(stored_bootdelay)) {
364 lock = IS_ENABLED(CONFIG_AUTOBOOT_KEYED) &&
365 !IS_ENABLED(CONFIG_AUTOBOOT_KEYED_CTRLC);
367 prev = disable_ctrlc(1); /* disable Ctrl-C checking */
369 run_command_list(s, -1, 0);
372 disable_ctrlc(prev); /* restore Ctrl-C checking */
375 if (IS_ENABLED(CONFIG_USE_AUTOBOOT_MENUKEY) &&
376 menukey == AUTOBOOT_MENUKEY) {
377 s = env_get("menucmd");
379 run_command_list(s, -1, 0);