hash: Add a flag to support saving hashes in the environment
Some hashing commands permit saving the hash in an environment variable,
and verifying a hash from there. But the crc32 command does not support
this. In order to permit crc32 to use the generic hashing infrastructure,
add a flag to select which behaviour to use.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/hash.c b/common/hash.c
index e3a6e43..462853d 100644
--- a/common/hash.c
+++ b/common/hash.c
@@ -58,19 +58,31 @@
* @algo: Hash algorithm being used
* @sum: Hash digest (algo->digest_size bytes)
* @dest: Destination, interpreted as a hex address if it starts
- * with * or otherwise as an environment variable.
+ * with * (or allow_env_vars is 0) or otherwise as an
+ * environment variable.
+ * @allow_env_vars: non-zero to permit storing the result to an
+ * variable environment
*/
static void store_result(struct hash_algo *algo, const u8 *sum,
- const char *dest)
+ const char *dest, int allow_env_vars)
{
unsigned int i;
+ int env_var = 0;
- if (*dest == '*') {
- u8 *ptr;
+ /*
+ * If environment variables are allowed, then we assume that 'dest'
+ * is an environment variable, unless it starts with *, in which
+ * case we assume it is an address. If not allowed, it is always an
+ * address. This is to support the crc32 command.
+ */
+ if (allow_env_vars) {
+ if (*dest == '*')
+ dest++;
+ else
+ env_var = 1;
+ }
- ptr = (u8 *)simple_strtoul(dest + 1, NULL, 16);
- memcpy(ptr, sum, algo->digest_size);
- } else {
+ if (env_var) {
char str_output[HASH_MAX_DIGEST_SIZE * 2 + 1];
char *str_ptr = str_output;
@@ -80,6 +92,11 @@
}
str_ptr = '\0';
setenv(dest, str_output);
+ } else {
+ u8 *ptr;
+
+ ptr = (u8 *)simple_strtoul(dest, NULL, 16);
+ memcpy(ptr, sum, algo->digest_size);
}
}
@@ -94,14 +111,28 @@
* Otherwise we assume it is an environment variable, and
* look up its value (it must contain a hex digest).
* @vsum: Returns binary digest value (algo->digest_size bytes)
+ * @allow_env_vars: non-zero to permit storing the result to an environment
+ * variable. If 0 then verify_str is assumed to be an
+ * address, and the * prefix is not expected.
* @return 0 if ok, non-zero on error
*/
-static int parse_verify_sum(struct hash_algo *algo, char *verify_str, u8 *vsum)
+static int parse_verify_sum(struct hash_algo *algo, char *verify_str, u8 *vsum,
+ int allow_env_vars)
{
- if (*verify_str == '*') {
+ int env_var = 0;
+
+ /* See comment above in store_result() */
+ if (allow_env_vars) {
+ if (*verify_str == '*')
+ verify_str++;
+ else
+ env_var = 1;
+ }
+
+ if (env_var) {
u8 *ptr;
- ptr = (u8 *)simple_strtoul(verify_str + 1, NULL, 16);
+ ptr = (u8 *)simple_strtoul(verify_str, NULL, 16);
memcpy(vsum, ptr, algo->digest_size);
} else {
unsigned int i;
@@ -158,7 +189,7 @@
printf("%02x", output[i]);
}
-int hash_command(const char *algo_name, int verify, cmd_tbl_t *cmdtp, int flag,
+int hash_command(const char *algo_name, int flags, cmd_tbl_t *cmdtp, int flag,
int argc, char * const argv[])
{
struct hash_algo *algo;
@@ -169,13 +200,14 @@
if (argc < 2)
return CMD_RET_USAGE;
+ addr = simple_strtoul(*argv++, NULL, 16);
+ len = simple_strtoul(*argv++, NULL, 16);
+
algo = find_hash_algo(algo_name);
if (!algo) {
printf("Unknown hash algorithm '%s'\n", algo_name);
return CMD_RET_USAGE;
}
- addr = simple_strtoul(*argv++, NULL, 16);
- len = simple_strtoul(*argv++, NULL, 16);
argc -= 2;
if (algo->digest_size > HASH_MAX_DIGEST_SIZE) {
@@ -188,13 +220,14 @@
/* Try to avoid code bloat when verify is not needed */
#ifdef CONFIG_HASH_VERIFY
- if (verify) {
+ if (flags & HASH_FLAG_VERIFY) {
#else
if (0) {
#endif
if (!argc)
return CMD_RET_USAGE;
- if (parse_verify_sum(algo, *argv, vsum)) {
+ if (parse_verify_sum(algo, *argv, vsum,
+ flags & HASH_FLAG_ENV)) {
printf("ERROR: %s does not contain a valid %s sum\n",
*argv, algo->name);
return 1;
@@ -213,8 +246,10 @@
show_hash(algo, addr, len, output);
printf("\n");
- if (argc)
- store_result(algo, output, *argv);
+ if (argc) {
+ store_result(algo, output, *argv,
+ flags & HASH_FLAG_ENV);
+ }
}
return 0;