1 /* 2 * Copyright (c) 2012 The Chromium OS Authors. 3 * 4 * (C) Copyright 2011 5 * Joe Hershberger, National Instruments, joe.hershberger@ni.com 6 * 7 * (C) Copyright 2000 8 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License as 12 * published by the Free Software Foundation; either version 2 of 13 * the License, or (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 23 * MA 02111-1307 USA 24 */ 25 26 #include <common.h> 27 #include <command.h> 28 #include <hash.h> 29 #include <sha1.h> 30 #include <sha256.h> 31 32 /* 33 * These are the hash algorithms we support. Chips which support accelerated 34 * crypto could perhaps add named version of these algorithms here. 35 */ 36 static struct hash_algo hash_algo[] = { 37 #ifdef CONFIG_SHA1 38 { 39 "SHA1", 40 SHA1_SUM_LEN, 41 sha1_csum_wd, 42 CHUNKSZ_SHA1, 43 }, 44 #endif 45 #ifdef CONFIG_SHA256 46 { 47 "SHA256", 48 SHA256_SUM_LEN, 49 sha256_csum_wd, 50 CHUNKSZ_SHA256, 51 }, 52 #endif 53 }; 54 55 /** 56 * store_result: Store the resulting sum to an address or variable 57 * 58 * @algo: Hash algorithm being used 59 * @sum: Hash digest (algo->digest_size bytes) 60 * @dest: Destination, interpreted as a hex address if it starts 61 * with * (or allow_env_vars is 0) or otherwise as an 62 * environment variable. 63 * @allow_env_vars: non-zero to permit storing the result to an 64 * variable environment 65 */ 66 static void store_result(struct hash_algo *algo, const u8 *sum, 67 const char *dest, int allow_env_vars) 68 { 69 unsigned int i; 70 int env_var = 0; 71 72 /* 73 * If environment variables are allowed, then we assume that 'dest' 74 * is an environment variable, unless it starts with *, in which 75 * case we assume it is an address. If not allowed, it is always an 76 * address. This is to support the crc32 command. 77 */ 78 if (allow_env_vars) { 79 if (*dest == '*') 80 dest++; 81 else 82 env_var = 1; 83 } 84 85 if (env_var) { 86 char str_output[HASH_MAX_DIGEST_SIZE * 2 + 1]; 87 char *str_ptr = str_output; 88 89 for (i = 0; i < algo->digest_size; i++) { 90 sprintf(str_ptr, "%02x", sum[i]); 91 str_ptr += 2; 92 } 93 str_ptr = '\0'; 94 setenv(dest, str_output); 95 } else { 96 u8 *ptr; 97 98 ptr = (u8 *)simple_strtoul(dest, NULL, 16); 99 memcpy(ptr, sum, algo->digest_size); 100 } 101 } 102 103 /** 104 * parse_verify_sum: Parse a hash verification parameter 105 * 106 * @algo: Hash algorithm being used 107 * @verify_str: Argument to parse. If it starts with * then it is 108 * interpreted as a hex address containing the hash. 109 * If the length is exactly the right number of hex digits 110 * for the digest size, then we assume it is a hex digest. 111 * Otherwise we assume it is an environment variable, and 112 * look up its value (it must contain a hex digest). 113 * @vsum: Returns binary digest value (algo->digest_size bytes) 114 * @allow_env_vars: non-zero to permit storing the result to an environment 115 * variable. If 0 then verify_str is assumed to be an 116 * address, and the * prefix is not expected. 117 * @return 0 if ok, non-zero on error 118 */ 119 static int parse_verify_sum(struct hash_algo *algo, char *verify_str, u8 *vsum, 120 int allow_env_vars) 121 { 122 int env_var = 0; 123 124 /* See comment above in store_result() */ 125 if (allow_env_vars) { 126 if (*verify_str == '*') 127 verify_str++; 128 else 129 env_var = 1; 130 } 131 132 if (env_var) { 133 u8 *ptr; 134 135 ptr = (u8 *)simple_strtoul(verify_str, NULL, 16); 136 memcpy(vsum, ptr, algo->digest_size); 137 } else { 138 unsigned int i; 139 char *vsum_str; 140 int digits = algo->digest_size * 2; 141 142 /* 143 * As with the original code from sha1sum.c, we assume that a 144 * string which matches the digest size exactly is a hex 145 * string and not an environment variable. 146 */ 147 if (strlen(verify_str) == digits) 148 vsum_str = verify_str; 149 else { 150 vsum_str = getenv(verify_str); 151 if (vsum_str == NULL || strlen(vsum_str) != digits) { 152 printf("Expected %d hex digits in env var\n", 153 digits); 154 return 1; 155 } 156 } 157 158 for (i = 0; i < algo->digest_size; i++) { 159 char *nullp = vsum_str + (i + 1) * 2; 160 char end = *nullp; 161 162 *nullp = '\0'; 163 vsum[i] = simple_strtoul(vsum_str + (i * 2), NULL, 16); 164 *nullp = end; 165 } 166 } 167 return 0; 168 } 169 170 static struct hash_algo *find_hash_algo(const char *name) 171 { 172 int i; 173 174 for (i = 0; i < ARRAY_SIZE(hash_algo); i++) { 175 if (!strcasecmp(name, hash_algo[i].name)) 176 return &hash_algo[i]; 177 } 178 179 return NULL; 180 } 181 182 static void show_hash(struct hash_algo *algo, ulong addr, ulong len, 183 u8 *output) 184 { 185 int i; 186 187 printf("%s for %08lx ... %08lx ==> ", algo->name, addr, addr + len - 1); 188 for (i = 0; i < algo->digest_size; i++) 189 printf("%02x", output[i]); 190 } 191 192 int hash_command(const char *algo_name, int flags, cmd_tbl_t *cmdtp, int flag, 193 int argc, char * const argv[]) 194 { 195 struct hash_algo *algo; 196 ulong addr, len; 197 u8 output[HASH_MAX_DIGEST_SIZE]; 198 u8 vsum[HASH_MAX_DIGEST_SIZE]; 199 200 if (argc < 2) 201 return CMD_RET_USAGE; 202 203 addr = simple_strtoul(*argv++, NULL, 16); 204 len = simple_strtoul(*argv++, NULL, 16); 205 206 algo = find_hash_algo(algo_name); 207 if (!algo) { 208 printf("Unknown hash algorithm '%s'\n", algo_name); 209 return CMD_RET_USAGE; 210 } 211 argc -= 2; 212 213 if (algo->digest_size > HASH_MAX_DIGEST_SIZE) { 214 puts("HASH_MAX_DIGEST_SIZE exceeded\n"); 215 return 1; 216 } 217 218 algo->hash_func_ws((const unsigned char *)addr, len, output, 219 algo->chunk_size); 220 221 /* Try to avoid code bloat when verify is not needed */ 222 #ifdef CONFIG_HASH_VERIFY 223 if (flags & HASH_FLAG_VERIFY) { 224 #else 225 if (0) { 226 #endif 227 if (!argc) 228 return CMD_RET_USAGE; 229 if (parse_verify_sum(algo, *argv, vsum, 230 flags & HASH_FLAG_ENV)) { 231 printf("ERROR: %s does not contain a valid %s sum\n", 232 *argv, algo->name); 233 return 1; 234 } 235 if (memcmp(output, vsum, algo->digest_size) != 0) { 236 int i; 237 238 show_hash(algo, addr, len, output); 239 printf(" != "); 240 for (i = 0; i < algo->digest_size; i++) 241 printf("%02x", vsum[i]); 242 puts(" ** ERROR **\n"); 243 return 1; 244 } 245 } else { 246 show_hash(algo, addr, len, output); 247 printf("\n"); 248 249 if (argc) { 250 store_result(algo, output, *argv, 251 flags & HASH_FLAG_ENV); 252 } 253 } 254 255 return 0; 256 } 257