[U-Boot] [PATCH v3 09/20] Add generic hash API
Simon Glass
sjg at chromium.org
Thu Dec 6 01:46:36 CET 2012
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: Simon Glass <sjg at chromium.org>
---
Changes in v3:
- Rename stricmp() to strcasecmp() to match Linux / POSIX
- Correct hash error message to show the algorithm name, not always SHA1
- Fix ordering of hash.o in Makefile
Changes in v2:
- Add generic hash API to allow SHA256 command to be added without duplication
common/Makefile | 1 +
common/hash.c | 221 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
include/hash.h | 69 +++++++++++++++++
3 files changed, 291 insertions(+), 0 deletions(-)
create mode 100644 common/hash.c
create mode 100644 include/hash.h
diff --git a/common/Makefile b/common/Makefile
index 84968f8..c451c3d 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -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
diff --git a/common/hash.c b/common/hash.c
new file mode 100644
index 0000000..e3a6e43
--- /dev/null
+++ b/common/hash.c
@@ -0,0 +1,221 @@
+/*
+ * Copyright (c) 2012 The Chromium OS Authors.
+ *
+ * (C) Copyright 2011
+ * Joe Hershberger, National Instruments, joe.hershberger at ni.com
+ *
+ * (C) Copyright 2000
+ * Wolfgang Denk, DENX Software Engineering, wd at 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;
+}
diff --git a/include/hash.h b/include/hash.h
new file mode 100644
index 0000000..34ba558
--- /dev/null
+++ b/include/hash.h
@@ -0,0 +1,69 @@
+/*
+ * 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
--
1.7.7.3
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