u-boot/common/hash.c
Nikolay Dimitrov 3ef46a998a Fix hash verification
Fix issue in parse_verify_sum() which swaps handling of env-var and *address.
Move hash_command() argc check earlier.
Cosmetic change on do_hash() variable declaration.
Improved help message for "hash" command.

Signed-off-by: Nikolay Dimitrov <picmaster@mail.bg>
Reviewed-by: Simon Glass <sjg@chromium.org>
2014-12-29 16:31:24 -05:00

427 lines
9.6 KiB
C

/*
* Copyright (c) 2012 The Chromium OS Authors.
*
* (C) Copyright 2011
* Joe Hershberger, National Instruments, joe.hershberger@ni.com
*
* (C) Copyright 2000
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <command.h>
#include <malloc.h>
#include <hw_sha.h>
#include <hash.h>
#include <u-boot/sha1.h>
#include <u-boot/sha256.h>
#include <asm/io.h>
#include <asm/errno.h>
#ifdef CONFIG_CMD_SHA1SUM
static int hash_init_sha1(struct hash_algo *algo, void **ctxp)
{
sha1_context *ctx = malloc(sizeof(sha1_context));
sha1_starts(ctx);
*ctxp = ctx;
return 0;
}
static int hash_update_sha1(struct hash_algo *algo, void *ctx, const void *buf,
unsigned int size, int is_last)
{
sha1_update((sha1_context *)ctx, buf, size);
return 0;
}
static int hash_finish_sha1(struct hash_algo *algo, void *ctx, void *dest_buf,
int size)
{
if (size < algo->digest_size)
return -1;
sha1_finish((sha1_context *)ctx, dest_buf);
free(ctx);
return 0;
}
#endif
#ifdef CONFIG_SHA256
static int hash_init_sha256(struct hash_algo *algo, void **ctxp)
{
sha256_context *ctx = malloc(sizeof(sha256_context));
sha256_starts(ctx);
*ctxp = ctx;
return 0;
}
static int hash_update_sha256(struct hash_algo *algo, void *ctx,
const void *buf, unsigned int size, int is_last)
{
sha256_update((sha256_context *)ctx, buf, size);
return 0;
}
static int hash_finish_sha256(struct hash_algo *algo, void *ctx, void
*dest_buf, int size)
{
if (size < algo->digest_size)
return -1;
sha256_finish((sha256_context *)ctx, dest_buf);
free(ctx);
return 0;
}
#endif
static int hash_init_crc32(struct hash_algo *algo, void **ctxp)
{
uint32_t *ctx = malloc(sizeof(uint32_t));
*ctx = 0;
*ctxp = ctx;
return 0;
}
static int hash_update_crc32(struct hash_algo *algo, void *ctx,
const void *buf, unsigned int size, int is_last)
{
*((uint32_t *)ctx) = crc32(*((uint32_t *)ctx), buf, size);
return 0;
}
static int hash_finish_crc32(struct hash_algo *algo, void *ctx, void *dest_buf,
int size)
{
if (size < algo->digest_size)
return -1;
*((uint32_t *)dest_buf) = *((uint32_t *)ctx);
free(ctx);
return 0;
}
/*
* These are the hash algorithms we support. Chips which support accelerated
* crypto could perhaps add named version of these algorithms here. Note that
* algorithm names must be in lower case.
*/
static struct hash_algo hash_algo[] = {
/*
* CONFIG_SHA_HW_ACCEL is defined if hardware acceleration is
* available.
*/
#ifdef CONFIG_SHA_HW_ACCEL
{
"sha1",
SHA1_SUM_LEN,
hw_sha1,
CHUNKSZ_SHA1,
}, {
"sha256",
SHA256_SUM_LEN,
hw_sha256,
CHUNKSZ_SHA256,
},
#endif
/*
* This is CONFIG_CMD_SHA1SUM instead of CONFIG_SHA1 since otherwise
* it bloats the code for boards which use SHA1 but not the 'hash'
* or 'sha1sum' commands.
*/
#ifdef CONFIG_CMD_SHA1SUM
{
"sha1",
SHA1_SUM_LEN,
sha1_csum_wd,
CHUNKSZ_SHA1,
hash_init_sha1,
hash_update_sha1,
hash_finish_sha1,
},
#define MULTI_HASH
#endif
#ifdef CONFIG_SHA256
{
"sha256",
SHA256_SUM_LEN,
sha256_csum_wd,
CHUNKSZ_SHA256,
hash_init_sha256,
hash_update_sha256,
hash_finish_sha256,
},
#define MULTI_HASH
#endif
{
"crc32",
4,
crc32_wd_buf,
CHUNKSZ_CRC32,
hash_init_crc32,
hash_update_crc32,
hash_finish_crc32,
},
};
#if defined(CONFIG_HASH_VERIFY) || defined(CONFIG_CMD_HASH)
#define MULTI_HASH
#endif
/* Try to minimize code size for boards that don't want much hashing */
#ifdef MULTI_HASH
#define multi_hash() 1
#else
#define multi_hash() 0
#endif
/**
* store_result: Store the resulting sum to an address or variable
*
* @algo: Hash algorithm being used
* @sum: Hash digest (algo->digest_size bytes)
* @dest: Destination, interpreted as a hex address if it starts
* 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 uint8_t *sum,
const char *dest, int allow_env_vars)
{
unsigned int i;
int env_var = 0;
/*
* 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;
}
if (env_var) {
char str_output[HASH_MAX_DIGEST_SIZE * 2 + 1];
char *str_ptr = str_output;
for (i = 0; i < algo->digest_size; i++) {
sprintf(str_ptr, "%02x", sum[i]);
str_ptr += 2;
}
*str_ptr = '\0';
setenv(dest, str_output);
} else {
ulong addr;
void *buf;
addr = simple_strtoul(dest, NULL, 16);
buf = map_sysmem(addr, algo->digest_size);
memcpy(buf, sum, algo->digest_size);
unmap_sysmem(buf);
}
}
/**
* parse_verify_sum: Parse a hash verification parameter
*
* @algo: Hash algorithm being used
* @verify_str: Argument to parse. If it starts with * then it is
* interpreted as a hex address containing the hash.
* If the length is exactly the right number of hex digits
* for the digest size, then we assume it is a hex digest.
* 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,
uint8_t *vsum, int allow_env_vars)
{
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) {
ulong addr;
void *buf;
addr = simple_strtoul(verify_str, NULL, 16);
buf = map_sysmem(addr, algo->digest_size);
memcpy(vsum, buf, algo->digest_size);
} else {
unsigned int i;
char *vsum_str;
int digits = algo->digest_size * 2;
/*
* As with the original code from sha1sum.c, we assume that a
* string which matches the digest size exactly is a hex
* string and not an environment variable.
*/
if (strlen(verify_str) == digits)
vsum_str = verify_str;
else {
vsum_str = getenv(verify_str);
if (vsum_str == NULL || strlen(vsum_str) != digits) {
printf("Expected %d hex digits in env var\n",
digits);
return 1;
}
}
for (i = 0; i < algo->digest_size; i++) {
char *nullp = vsum_str + (i + 1) * 2;
char end = *nullp;
*nullp = '\0';
vsum[i] = simple_strtoul(vsum_str + (i * 2), NULL, 16);
*nullp = end;
}
}
return 0;
}
int hash_lookup_algo(const char *algo_name, struct hash_algo **algop)
{
int i;
for (i = 0; i < ARRAY_SIZE(hash_algo); i++) {
if (!strcmp(algo_name, hash_algo[i].name)) {
*algop = &hash_algo[i];
return 0;
}
}
debug("Unknown hash algorithm '%s'\n", algo_name);
return -EPROTONOSUPPORT;
}
void hash_show(struct hash_algo *algo, ulong addr, ulong len, uint8_t *output)
{
int i;
printf("%s for %08lx ... %08lx ==> ", algo->name, addr, addr + len - 1);
for (i = 0; i < algo->digest_size; i++)
printf("%02x", output[i]);
}
int hash_block(const char *algo_name, const void *data, unsigned int len,
uint8_t *output, int *output_size)
{
struct hash_algo *algo;
int ret;
ret = hash_lookup_algo(algo_name, &algo);
if (ret)
return ret;
if (output_size && *output_size < algo->digest_size) {
debug("Output buffer size %d too small (need %d bytes)",
*output_size, algo->digest_size);
return -ENOSPC;
}
if (output_size)
*output_size = algo->digest_size;
algo->hash_func_ws(data, len, output, algo->chunk_size);
return 0;
}
int hash_command(const char *algo_name, int flags, cmd_tbl_t *cmdtp, int flag,
int argc, char * const argv[])
{
ulong addr, len;
if ((argc < 2) || ((flags & HASH_FLAG_VERIFY) && (argc < 3)))
return CMD_RET_USAGE;
addr = simple_strtoul(*argv++, NULL, 16);
len = simple_strtoul(*argv++, NULL, 16);
if (multi_hash()) {
struct hash_algo *algo;
uint8_t output[HASH_MAX_DIGEST_SIZE];
uint8_t vsum[HASH_MAX_DIGEST_SIZE];
void *buf;
if (hash_lookup_algo(algo_name, &algo)) {
printf("Unknown hash algorithm '%s'\n", algo_name);
return CMD_RET_USAGE;
}
argc -= 2;
if (algo->digest_size > HASH_MAX_DIGEST_SIZE) {
puts("HASH_MAX_DIGEST_SIZE exceeded\n");
return 1;
}
buf = map_sysmem(addr, len);
algo->hash_func_ws(buf, len, output, algo->chunk_size);
unmap_sysmem(buf);
/* Try to avoid code bloat when verify is not needed */
#ifdef CONFIG_HASH_VERIFY
if (flags & HASH_FLAG_VERIFY) {
#else
if (0) {
#endif
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;
}
if (memcmp(output, vsum, algo->digest_size) != 0) {
int i;
hash_show(algo, addr, len, output);
printf(" != ");
for (i = 0; i < algo->digest_size; i++)
printf("%02x", vsum[i]);
puts(" ** ERROR **\n");
return 1;
}
} else {
hash_show(algo, addr, len, output);
printf("\n");
if (argc) {
store_result(algo, output, *argv,
flags & HASH_FLAG_ENV);
}
}
/* Horrible code size hack for boards that just want crc32 */
} else {
ulong crc;
ulong *ptr;
crc = crc32_wd(0, (const uchar *)addr, len, CHUNKSZ_CRC32);
printf("CRC32 for %08lx ... %08lx ==> %08lx\n",
addr, addr + len - 1, crc);
if (argc >= 3) {
ptr = (ulong *)simple_strtoul(argv[0], NULL, 16);
*ptr = crc;
}
}
return 0;
}