From d5b76673a5dfe0b5250baea3c36cdfa7a9fd5230 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Sun, 24 Feb 2013 17:33:26 +0000 Subject: [PATCH] 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 --- common/cmd_hash.c | 8 +++--- common/cmd_sha1sum.c | 6 ++--- common/hash.c | 69 +++++++++++++++++++++++++++++++++++++++------------- include/hash.h | 9 +++++-- 4 files changed, 66 insertions(+), 26 deletions(-) diff --git a/common/cmd_hash.c b/common/cmd_hash.c index eb6a338..8c03b5c 100644 --- a/common/cmd_hash.c +++ b/common/cmd_hash.c @@ -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 diff --git a/common/cmd_sha1sum.c b/common/cmd_sha1sum.c index fe927ab..9f08629 100644 --- a/common/cmd_sha1sum.c +++ b/common/cmd_sha1sum.c @@ -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 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 @@ 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; diff --git a/include/hash.h b/include/hash.h index 34ba558..88fa2b5 100644 --- a/include/hash.h +++ b/include/hash.h @@ -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