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>
This commit is contained in:
Simon Glass 2013-02-24 17:33:26 +00:00
parent 0ccff500cf
commit d5b76673a5
4 changed files with 66 additions and 26 deletions

View File

@ -30,22 +30,22 @@
static int do_hash(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
#ifdef CONFIG_HASH_VERIFY
int verify = 0;
int flags = HASH_FLAG_ENV;
if (argc < 4)
return CMD_RET_USAGE;
if (!strcmp(argv[1], "-v")) {
verify = 1;
flags |= HASH_FLAG_VERIFY;
argc--;
argv++;
}
#else
const int verify = 0;
const int flags = HASH_FLAG_ENV;
#endif
/* Move forward to 'algorithm' parameter */
argc--;
argv++;
return hash_command(*argv, verify, cmdtp, flag, argc - 1, argv + 1);
return hash_command(*argv, flags, cmdtp, flag, argc - 1, argv + 1);
}
#ifdef CONFIG_HASH_VERIFY

View File

@ -31,7 +31,7 @@
int do_sha1sum(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int verify = 0;
int flags = HASH_FLAG_ENV;
int ac;
char * const *av;
@ -42,13 +42,13 @@ int do_sha1sum(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
ac = argc - 1;
#ifdef CONFIG_SHA1SUM_VERIFY
if (strcmp(*av, "-v") == 0) {
verify = 1;
flags |= HASH_FLAG_VERIFY;
av++;
ac--;
}
#endif
return hash_command("sha1", verify, cmdtp, flag, ac, av);
return hash_command("sha1", flags, cmdtp, flag, ac, av);
}
#ifdef CONFIG_SHA1SUM_VERIFY

View File

@ -58,19 +58,31 @@ static struct hash_algo hash_algo[] = {
* @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 @@ static void store_result(struct hash_algo *algo, const u8 *sum,
}
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 @@ static void store_result(struct hash_algo *algo, const u8 *sum,
* 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 @@ static void show_hash(struct hash_algo *algo, ulong addr, ulong len,
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 @@ int hash_command(const char *algo_name, int verify, cmd_tbl_t *cmdtp, int flag,
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 @@ int hash_command(const char *algo_name, int verify, cmd_tbl_t *cmdtp, int flag,
/* 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 @@ int hash_command(const char *algo_name, int verify, cmd_tbl_t *cmdtp, int flag,
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;

View File

@ -51,19 +51,24 @@ struct hash_algo {
*/
#define HASH_MAX_DIGEST_SIZE 32
enum {
HASH_FLAG_VERIFY = 1 << 0, /* Enable verify mode */
HASH_FLAG_ENV = 1 << 1, /* Allow env vars */
};
/**
* hash_command: Process a hash command for a particular algorithm
*
* This common function is used to implement specific hash commands.
*
* @algo_name: Hash algorithm being used
* @verify: Non-zero to enable verify mode
* @flags: Flags value (HASH_FLAG_...)
* @cmdtp: Pointer to command table entry
* @flag: Some flags normally 0 (see CMD_FLAG_.. above)
* @argc: Number of arguments (arg 0 must be the command text)
* @argv: Arguments
*/
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[]);
#endif