Commit 460408ef authored by Simon Glass's avatar Simon Glass Committed by Tom Rini

Add generic hash API

We have a SHA1 command and want to add a SHA256 command also. Instead of
duplicating the code, create a generic hash API which can process
commands for different algorithms.
Signed-off-by: default avatarSimon Glass <sjg@chromium.org>
parent b1f17bf5
......@@ -30,6 +30,7 @@ ifndef CONFIG_SPL_BUILD
COBJS-y += main.o
COBJS-y += command.o
COBJS-y += exports.o
COBJS-y += hash.o
COBJS-$(CONFIG_SYS_HUSH_PARSER) += hush.o
COBJS-y += s_record.o
COBJS-y += xyzModem.o
......
/*
* 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.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <command.h>
#include <hash.h>
#include <sha1.h>
#include <sha256.h>
/*
* These are the hash algorithms we support. Chips which support accelerated
* crypto could perhaps add named version of these algorithms here.
*/
static struct hash_algo hash_algo[] = {
#ifdef CONFIG_SHA1
{
"SHA1",
SHA1_SUM_LEN,
sha1_csum_wd,
CHUNKSZ_SHA1,
},
#endif
#ifdef CONFIG_SHA256
{
"SHA256",
SHA256_SUM_LEN,
sha256_csum_wd,
CHUNKSZ_SHA256,
},
#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 otherwise as an environment variable.
*/
static void store_result(struct hash_algo *algo, const u8 *sum,
const char *dest)
{
unsigned int i;
if (*dest == '*') {
u8 *ptr;
ptr = (u8 *)simple_strtoul(dest + 1, NULL, 16);
memcpy(ptr, sum, algo->digest_size);
} else {
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);
}
}
/**
* 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)
* @return 0 if ok, non-zero on error
*/
static int parse_verify_sum(struct hash_algo *algo, char *verify_str, u8 *vsum)
{
if (*verify_str == '*') {
u8 *ptr;
ptr = (u8 *)simple_strtoul(verify_str + 1, NULL, 16);
memcpy(vsum, ptr, 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;
}
static struct hash_algo *find_hash_algo(const char *name)
{
int i;
for (i = 0; i < ARRAY_SIZE(hash_algo); i++) {
if (!strcasecmp(name, hash_algo[i].name))
return &hash_algo[i];
}
return NULL;
}
static void show_hash(struct hash_algo *algo, ulong addr, ulong len,
u8 *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_command(const char *algo_name, int verify, cmd_tbl_t *cmdtp, int flag,
int argc, char * const argv[])
{
struct hash_algo *algo;
ulong addr, len;
u8 output[HASH_MAX_DIGEST_SIZE];
u8 vsum[HASH_MAX_DIGEST_SIZE];
if (argc < 2)
return CMD_RET_USAGE;
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) {
puts("HASH_MAX_DIGEST_SIZE exceeded\n");
return 1;
}
algo->hash_func_ws((const unsigned char *)addr, len, output,
algo->chunk_size);
/* Try to avoid code bloat when verify is not needed */
#ifdef CONFIG_HASH_VERIFY
if (verify) {
#else
if (0) {
#endif
if (!argc)
return CMD_RET_USAGE;
if (parse_verify_sum(algo, *argv, vsum)) {
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;
show_hash(algo, addr, len, output);
printf(" != ");
for (i = 0; i < algo->digest_size; i++)
printf("%02x", vsum[i]);
puts(" ** ERROR **\n");
return 1;
}
} else {
show_hash(algo, addr, len, output);
printf("\n");
if (argc)
store_result(algo, output, *argv);
}
return 0;
}
/*
* Copyright (c) 2012 The Chromium OS Authors.
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#ifndef _HASH_H
#define _HASH_H
#ifdef CONFIG_SHA1SUM_VERIFY
#define CONFIG_HASH_VERIFY
#endif
struct hash_algo {
const char *name; /* Name of algorithm */
int digest_size; /* Length of digest */
/**
* hash_func_ws: Generic hashing function
*
* This is the generic prototype for a hashing function. We only
* have the watchdog version at present.
*
* @input: Input buffer
* @ilen: Input buffer length
* @output: Checksum result (length depends on algorithm)
* @chunk_sz: Trigger watchdog after processing this many bytes
*/
void (*hash_func_ws)(const unsigned char *input, unsigned int ilen,
unsigned char *output, unsigned int chunk_sz);
int chunk_size; /* Watchdog chunk size */
};
/*
* Maximum digest size for all algorithms we support. Having this value
* avoids a malloc() or C99 local declaration in common/cmd_hash.c.
*/
#define HASH_MAX_DIGEST_SIZE 32
/**
* 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
* @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 argc, char * const argv[]);
#endif
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