xref: /openbmc/u-boot/common/hash.c (revision 7d3ca0f8) 
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  * SPDX-License-Identifier:	GPL-2.0+
11  */
12 
13 #include <common.h>
14 #include <command.h>
15 #include <malloc.h>
16 #include <hw_sha.h>
17 #include <hash.h>
18 #include <sha1.h>
19 #include <sha256.h>
20 #include <asm/io.h>
21 #include <asm/errno.h>
22 
23 #ifdef CONFIG_CMD_SHA1SUM
24 static int hash_init_sha1(struct hash_algo *algo, void **ctxp)
25 {
26 	sha1_context *ctx = malloc(sizeof(sha1_context));
27 	sha1_starts(ctx);
28 	*ctxp = ctx;
29 	return 0;
30 }
31 
32 static int hash_update_sha1(struct hash_algo *algo, void *ctx, const void *buf,
33 			    unsigned int size, int is_last)
34 {
35 	sha1_update((sha1_context *)ctx, buf, size);
36 	return 0;
37 }
38 
39 static int hash_finish_sha1(struct hash_algo *algo, void *ctx, void *dest_buf,
40 			    int size)
41 {
42 	if (size < algo->digest_size)
43 		return -1;
44 
45 	sha1_finish((sha1_context *)ctx, dest_buf);
46 	free(ctx);
47 	return 0;
48 }
49 #endif
50 
51 #ifdef CONFIG_SHA256
52 static int hash_init_sha256(struct hash_algo *algo, void **ctxp)
53 {
54 	sha256_context *ctx = malloc(sizeof(sha256_context));
55 	sha256_starts(ctx);
56 	*ctxp = ctx;
57 	return 0;
58 }
59 
60 static int hash_update_sha256(struct hash_algo *algo, void *ctx,
61 			      const void *buf, unsigned int size, int is_last)
62 {
63 	sha256_update((sha256_context *)ctx, buf, size);
64 	return 0;
65 }
66 
67 static int hash_finish_sha256(struct hash_algo *algo, void *ctx, void
68 			      *dest_buf, int size)
69 {
70 	if (size < algo->digest_size)
71 		return -1;
72 
73 	sha256_finish((sha256_context *)ctx, dest_buf);
74 	free(ctx);
75 	return 0;
76 }
77 #endif
78 
79 static int hash_init_crc32(struct hash_algo *algo, void **ctxp)
80 {
81 	uint32_t *ctx = malloc(sizeof(uint32_t));
82 	*ctx = 0;
83 	*ctxp = ctx;
84 	return 0;
85 }
86 
87 static int hash_update_crc32(struct hash_algo *algo, void *ctx,
88 			     const void *buf, unsigned int size, int is_last)
89 {
90 	*((uint32_t *)ctx) = crc32(*((uint32_t *)ctx), buf, size);
91 	return 0;
92 }
93 
94 static int hash_finish_crc32(struct hash_algo *algo, void *ctx, void *dest_buf,
95 			     int size)
96 {
97 	if (size < algo->digest_size)
98 		return -1;
99 
100 	*((uint32_t *)dest_buf) = *((uint32_t *)ctx);
101 	free(ctx);
102 	return 0;
103 }
104 
105 /*
106  * These are the hash algorithms we support. Chips which support accelerated
107  * crypto could perhaps add named version of these algorithms here. Note that
108  * algorithm names must be in lower case.
109  */
110 static struct hash_algo hash_algo[] = {
111 	/*
112 	 * CONFIG_SHA_HW_ACCEL is defined if hardware acceleration is
113 	 * available.
114 	 */
115 #ifdef CONFIG_SHA_HW_ACCEL
116 	{
117 		"sha1",
118 		SHA1_SUM_LEN,
119 		hw_sha1,
120 		CHUNKSZ_SHA1,
121 	}, {
122 		"sha256",
123 		SHA256_SUM_LEN,
124 		hw_sha256,
125 		CHUNKSZ_SHA256,
126 	},
127 #endif
128 	/*
129 	 * This is CONFIG_CMD_SHA1SUM instead of CONFIG_SHA1 since otherwise
130 	 * it bloats the code for boards which use SHA1 but not the 'hash'
131 	 * or 'sha1sum' commands.
132 	 */
133 #ifdef CONFIG_CMD_SHA1SUM
134 	{
135 		"sha1",
136 		SHA1_SUM_LEN,
137 		sha1_csum_wd,
138 		CHUNKSZ_SHA1,
139 		hash_init_sha1,
140 		hash_update_sha1,
141 		hash_finish_sha1,
142 	},
143 #define MULTI_HASH
144 #endif
145 #ifdef CONFIG_SHA256
146 	{
147 		"sha256",
148 		SHA256_SUM_LEN,
149 		sha256_csum_wd,
150 		CHUNKSZ_SHA256,
151 		hash_init_sha256,
152 		hash_update_sha256,
153 		hash_finish_sha256,
154 	},
155 #define MULTI_HASH
156 #endif
157 	{
158 		"crc32",
159 		4,
160 		crc32_wd_buf,
161 		CHUNKSZ_CRC32,
162 		hash_init_crc32,
163 		hash_update_crc32,
164 		hash_finish_crc32,
165 	},
166 };
167 
168 #if defined(CONFIG_HASH_VERIFY) || defined(CONFIG_CMD_HASH)
169 #define MULTI_HASH
170 #endif
171 
172 /* Try to minimize code size for boards that don't want much hashing */
173 #ifdef MULTI_HASH
174 #define multi_hash()	1
175 #else
176 #define multi_hash()	0
177 #endif
178 
179 /**
180  * store_result: Store the resulting sum to an address or variable
181  *
182  * @algo:		Hash algorithm being used
183  * @sum:		Hash digest (algo->digest_size bytes)
184  * @dest:		Destination, interpreted as a hex address if it starts
185  *			with * (or allow_env_vars is 0) or otherwise as an
186  *			environment variable.
187  * @allow_env_vars:	non-zero to permit storing the result to an
188  *			variable environment
189  */
190 static void store_result(struct hash_algo *algo, const u8 *sum,
191 			 const char *dest, int allow_env_vars)
192 {
193 	unsigned int i;
194 	int env_var = 0;
195 
196 	/*
197 	 * If environment variables are allowed, then we assume that 'dest'
198 	 * is an environment variable, unless it starts with *, in which
199 	 * case we assume it is an address. If not allowed, it is always an
200 	 * address. This is to support the crc32 command.
201 	 */
202 	if (allow_env_vars) {
203 		if (*dest == '*')
204 			dest++;
205 		else
206 			env_var = 1;
207 	}
208 
209 	if (env_var) {
210 		char str_output[HASH_MAX_DIGEST_SIZE * 2 + 1];
211 		char *str_ptr = str_output;
212 
213 		for (i = 0; i < algo->digest_size; i++) {
214 			sprintf(str_ptr, "%02x", sum[i]);
215 			str_ptr += 2;
216 		}
217 		str_ptr = '\0';
218 		setenv(dest, str_output);
219 	} else {
220 		ulong addr;
221 		void *buf;
222 
223 		addr = simple_strtoul(dest, NULL, 16);
224 		buf = map_sysmem(addr, algo->digest_size);
225 		memcpy(buf, sum, algo->digest_size);
226 		unmap_sysmem(buf);
227 	}
228 }
229 
230 /**
231  * parse_verify_sum: Parse a hash verification parameter
232  *
233  * @algo:		Hash algorithm being used
234  * @verify_str:		Argument to parse. If it starts with * then it is
235  *			interpreted as a hex address containing the hash.
236  *			If the length is exactly the right number of hex digits
237  *			for the digest size, then we assume it is a hex digest.
238  *			Otherwise we assume it is an environment variable, and
239  *			look up its value (it must contain a hex digest).
240  * @vsum:		Returns binary digest value (algo->digest_size bytes)
241  * @allow_env_vars:	non-zero to permit storing the result to an environment
242  *			variable. If 0 then verify_str is assumed to be an
243  *			address, and the * prefix is not expected.
244  * @return 0 if ok, non-zero on error
245  */
246 static int parse_verify_sum(struct hash_algo *algo, char *verify_str, u8 *vsum,
247 			    int allow_env_vars)
248 {
249 	int env_var = 0;
250 
251 	/* See comment above in store_result() */
252 	if (allow_env_vars) {
253 		if (*verify_str == '*')
254 			verify_str++;
255 		else
256 			env_var = 1;
257 	}
258 
259 	if (env_var) {
260 		ulong addr;
261 		void *buf;
262 
263 		addr = simple_strtoul(verify_str, NULL, 16);
264 		buf = map_sysmem(addr, algo->digest_size);
265 		memcpy(vsum, buf, algo->digest_size);
266 	} else {
267 		unsigned int i;
268 		char *vsum_str;
269 		int digits = algo->digest_size * 2;
270 
271 		/*
272 		 * As with the original code from sha1sum.c, we assume that a
273 		 * string which matches the digest size exactly is a hex
274 		 * string and not an environment variable.
275 		 */
276 		if (strlen(verify_str) == digits)
277 			vsum_str = verify_str;
278 		else {
279 			vsum_str = getenv(verify_str);
280 			if (vsum_str == NULL || strlen(vsum_str) != digits) {
281 				printf("Expected %d hex digits in env var\n",
282 				       digits);
283 				return 1;
284 			}
285 		}
286 
287 		for (i = 0; i < algo->digest_size; i++) {
288 			char *nullp = vsum_str + (i + 1) * 2;
289 			char end = *nullp;
290 
291 			*nullp = '\0';
292 			vsum[i] = simple_strtoul(vsum_str + (i * 2), NULL, 16);
293 			*nullp = end;
294 		}
295 	}
296 	return 0;
297 }
298 
299 int hash_lookup_algo(const char *algo_name, struct hash_algo **algop)
300 {
301 	int i;
302 
303 	for (i = 0; i < ARRAY_SIZE(hash_algo); i++) {
304 		if (!strcmp(algo_name, hash_algo[i].name)) {
305 			*algop = &hash_algo[i];
306 			return 0;
307 		}
308 	}
309 
310 	debug("Unknown hash algorithm '%s'\n", algo_name);
311 	return -EPROTONOSUPPORT;
312 }
313 
314 static void show_hash(struct hash_algo *algo, ulong addr, ulong len,
315 		      u8 *output)
316 {
317 	int i;
318 
319 	printf("%s for %08lx ... %08lx ==> ", algo->name, addr, addr + len - 1);
320 	for (i = 0; i < algo->digest_size; i++)
321 		printf("%02x", output[i]);
322 }
323 
324 int hash_block(const char *algo_name, const void *data, unsigned int len,
325 	       uint8_t *output, int *output_size)
326 {
327 	struct hash_algo *algo;
328 	int ret;
329 
330 	ret = hash_lookup_algo(algo_name, &algo);
331 	if (ret)
332 		return ret;
333 
334 	if (output_size && *output_size < algo->digest_size) {
335 		debug("Output buffer size %d too small (need %d bytes)",
336 		      *output_size, algo->digest_size);
337 		return -ENOSPC;
338 	}
339 	if (output_size)
340 		*output_size = algo->digest_size;
341 	algo->hash_func_ws(data, len, output, algo->chunk_size);
342 
343 	return 0;
344 }
345 
346 int hash_command(const char *algo_name, int flags, cmd_tbl_t *cmdtp, int flag,
347 		 int argc, char * const argv[])
348 {
349 	ulong addr, len;
350 
351 	if (argc < 2)
352 		return CMD_RET_USAGE;
353 
354 	addr = simple_strtoul(*argv++, NULL, 16);
355 	len = simple_strtoul(*argv++, NULL, 16);
356 
357 	if (multi_hash()) {
358 		struct hash_algo *algo;
359 		u8 output[HASH_MAX_DIGEST_SIZE];
360 		u8 vsum[HASH_MAX_DIGEST_SIZE];
361 		void *buf;
362 
363 		if (hash_lookup_algo(algo_name, &algo)) {
364 			printf("Unknown hash algorithm '%s'\n", algo_name);
365 			return CMD_RET_USAGE;
366 		}
367 		argc -= 2;
368 
369 		if (algo->digest_size > HASH_MAX_DIGEST_SIZE) {
370 			puts("HASH_MAX_DIGEST_SIZE exceeded\n");
371 			return 1;
372 		}
373 
374 		buf = map_sysmem(addr, len);
375 		algo->hash_func_ws(buf, len, output, algo->chunk_size);
376 		unmap_sysmem(buf);
377 
378 		/* Try to avoid code bloat when verify is not needed */
379 #ifdef CONFIG_HASH_VERIFY
380 		if (flags & HASH_FLAG_VERIFY) {
381 #else
382 		if (0) {
383 #endif
384 			if (!argc)
385 				return CMD_RET_USAGE;
386 			if (parse_verify_sum(algo, *argv, vsum,
387 					flags & HASH_FLAG_ENV)) {
388 				printf("ERROR: %s does not contain a valid "
389 					"%s sum\n", *argv, algo->name);
390 				return 1;
391 			}
392 			if (memcmp(output, vsum, algo->digest_size) != 0) {
393 				int i;
394 
395 				show_hash(algo, addr, len, output);
396 				printf(" != ");
397 				for (i = 0; i < algo->digest_size; i++)
398 					printf("%02x", vsum[i]);
399 				puts(" ** ERROR **\n");
400 				return 1;
401 			}
402 		} else {
403 			show_hash(algo, addr, len, output);
404 			printf("\n");
405 
406 			if (argc) {
407 				store_result(algo, output, *argv,
408 					flags & HASH_FLAG_ENV);
409 			}
410 		}
411 
412 	/* Horrible code size hack for boards that just want crc32 */
413 	} else {
414 		ulong crc;
415 		ulong *ptr;
416 
417 		crc = crc32_wd(0, (const uchar *)addr, len, CHUNKSZ_CRC32);
418 
419 		printf("CRC32 for %08lx ... %08lx ==> %08lx\n",
420 				addr, addr + len - 1, crc);
421 
422 		if (argc >= 3) {
423 			ptr = (ulong *)simple_strtoul(argv[0], NULL, 16);
424 			*ptr = crc;
425 		}
426 	}
427 
428 	return 0;
429 }
430