1 /*
2  * Copyright 2015 Freescale Semiconductor, Inc.
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <fsl_validate.h>
9 #include <fsl_secboot_err.h>
10 #include <fsl_sfp.h>
11 #include <fsl_sec.h>
12 #include <command.h>
13 #include <malloc.h>
14 #include <dm/uclass.h>
15 #include <u-boot/rsa-mod-exp.h>
16 #include <hash.h>
17 #include <fsl_secboot_err.h>
18 #ifdef CONFIG_LS102XA
19 #include <asm/arch/immap_ls102xa.h>
20 #endif
21 
22 #define SHA256_BITS	256
23 #define SHA256_BYTES	(256/8)
24 #define SHA256_NIBBLES	(256/4)
25 #define NUM_HEX_CHARS	(sizeof(ulong) * 2)
26 
27 #define CHECK_KEY_LEN(key_len)	(((key_len) == 2 * KEY_SIZE_BYTES / 4) || \
28 				 ((key_len) == 2 * KEY_SIZE_BYTES / 2) || \
29 				 ((key_len) == 2 * KEY_SIZE_BYTES))
30 
31 /* This array contains DER value for SHA-256 */
32 static const u8 hash_identifier[] = { 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60,
33 		0x86, 0x48, 0x01, 0x65,	0x03, 0x04, 0x02, 0x01, 0x05, 0x00,
34 		0x04, 0x20
35 		};
36 
37 static u8 hash_val[SHA256_BYTES];
38 
39 #ifdef CONFIG_ESBC_HDR_LS
40 /* New Barker Code for LS ESBC Header */
41 static const u8 barker_code[ESBC_BARKER_LEN] = { 0x12, 0x19, 0x20, 0x01 };
42 #else
43 static const u8 barker_code[ESBC_BARKER_LEN] = { 0x68, 0x39, 0x27, 0x81 };
44 #endif
45 
46 void branch_to_self(void) __attribute__ ((noreturn));
47 
48 /*
49  * This function will put core in infinite loop.
50  * This will be called when the ESBC can not proceed further due
51  * to some unknown errors.
52  */
53 void branch_to_self(void)
54 {
55 	printf("Core is in infinite loop due to errors.\n");
56 self:
57 	goto self;
58 }
59 
60 #if defined(CONFIG_FSL_ISBC_KEY_EXT)
61 static u32 check_ie(struct fsl_secboot_img_priv *img)
62 {
63 	if (img->hdr.ie_flag)
64 		return 1;
65 
66 	return 0;
67 }
68 
69 /* This function returns the CSF Header Address of uboot
70  * For MPC85xx based platforms, the LAW mapping for NOR
71  * flash changes in uboot code. Hence the offset needs
72  * to be calculated and added to the new NOR flash base
73  * address
74  */
75 #if defined(CONFIG_MPC85xx)
76 int get_csf_base_addr(u32 *csf_addr, u32 *flash_base_addr)
77 {
78 	struct ccsr_gur __iomem *gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
79 	u32 csf_hdr_addr = in_be32(&gur->scratchrw[0]);
80 	u32 csf_flash_offset = csf_hdr_addr & ~(CONFIG_SYS_PBI_FLASH_BASE);
81 	u32 flash_addr, addr;
82 	int found = 0;
83 	int i = 0;
84 
85 	for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++) {
86 		flash_addr = flash_info[i].start[0];
87 		addr = flash_info[i].start[0] + csf_flash_offset;
88 		if (memcmp((u8 *)addr, barker_code, ESBC_BARKER_LEN) == 0) {
89 			debug("Barker found on addr %x\n", addr);
90 			found = 1;
91 			break;
92 		}
93 	}
94 
95 	if (!found)
96 		return -1;
97 
98 	*csf_addr = addr;
99 	*flash_base_addr = flash_addr;
100 
101 	return 0;
102 }
103 #else
104 /* For platforms like LS1020, correct flash address is present in
105  * the header. So the function reqturns flash base address as 0
106  */
107 int get_csf_base_addr(u32 *csf_addr, u32 *flash_base_addr)
108 {
109 	struct ccsr_gur __iomem *gur = (void *)(CONFIG_SYS_FSL_GUTS_ADDR);
110 	u32 csf_hdr_addr = in_be32(&gur->scratchrw[0]);
111 
112 	if (memcmp((u8 *)(uintptr_t)csf_hdr_addr,
113 		   barker_code, ESBC_BARKER_LEN))
114 		return -1;
115 
116 	*csf_addr = csf_hdr_addr;
117 	*flash_base_addr = 0;
118 	return 0;
119 }
120 #endif
121 
122 static int get_ie_info_addr(u32 *ie_addr)
123 {
124 	struct fsl_secboot_img_hdr *hdr;
125 	struct fsl_secboot_sg_table *sg_tbl;
126 	u32 flash_base_addr, csf_addr;
127 
128 	if (get_csf_base_addr(&csf_addr, &flash_base_addr))
129 		return -1;
130 
131 	hdr = (struct fsl_secboot_img_hdr *)(uintptr_t)csf_addr;
132 
133 	/* For SoC's with Trust Architecture v1 with corenet bus
134 	 * the sg table field in CSF header has absolute address
135 	 * for sg table in memory. In other Trust Architecture,
136 	 * this field specifies the offset of sg table from the
137 	 * base address of CSF Header
138 	 */
139 #if defined(CONFIG_FSL_TRUST_ARCH_v1) && defined(CONFIG_FSL_CORENET)
140 	sg_tbl = (struct fsl_secboot_sg_table *)
141 		 (((u32)hdr->psgtable & ~(CONFIG_SYS_PBI_FLASH_BASE)) +
142 		  flash_base_addr);
143 #else
144 	sg_tbl = (struct fsl_secboot_sg_table *)(uintptr_t)(csf_addr +
145 						 (u32)hdr->psgtable);
146 #endif
147 
148 	/* IE Key Table is the first entry in the SG Table */
149 #if defined(CONFIG_MPC85xx)
150 	*ie_addr = (sg_tbl->src_addr & ~(CONFIG_SYS_PBI_FLASH_BASE)) +
151 		   flash_base_addr;
152 #else
153 	*ie_addr = sg_tbl->src_addr;
154 #endif
155 
156 	debug("IE Table address is %x\n", *ie_addr);
157 	return 0;
158 }
159 
160 #endif
161 
162 #ifdef CONFIG_KEY_REVOCATION
163 /* This function checks srk_table_flag in header and set/reset srk_flag.*/
164 static u32 check_srk(struct fsl_secboot_img_priv *img)
165 {
166 #ifdef CONFIG_ESBC_HDR_LS
167 	/* In LS, No SRK Flag as SRK is always present*/
168 	return 1;
169 #else
170 	if (img->hdr.len_kr.srk_table_flag & SRK_FLAG)
171 		return 1;
172 
173 	return 0;
174 #endif
175 }
176 
177 /* This function returns ospr's key_revoc values.*/
178 static u32 get_key_revoc(void)
179 {
180 	struct ccsr_sfp_regs *sfp_regs = (void *)(CONFIG_SYS_SFP_ADDR);
181 	return (sfp_in32(&sfp_regs->ospr) & OSPR_KEY_REVOC_MASK) >>
182 		OSPR_KEY_REVOC_SHIFT;
183 }
184 
185 /* This function checks if selected key is revoked or not.*/
186 static u32 is_key_revoked(u32 keynum, u32 rev_flag)
187 {
188 	if (keynum == UNREVOCABLE_KEY)
189 		return 0;
190 
191 	if ((u32)(1 << (ALIGN_REVOC_KEY - keynum)) & rev_flag)
192 		return 1;
193 
194 	return 0;
195 }
196 
197 /* It read validates srk_table key lengths.*/
198 static u32 read_validate_srk_tbl(struct fsl_secboot_img_priv *img)
199 {
200 	int i = 0;
201 	u32 ret, key_num, key_revoc_flag, size;
202 	struct fsl_secboot_img_hdr *hdr = &img->hdr;
203 	void *esbc = (u8 *)(uintptr_t)img->ehdrloc;
204 
205 	if ((hdr->len_kr.num_srk == 0) ||
206 	    (hdr->len_kr.num_srk > MAX_KEY_ENTRIES))
207 		return ERROR_ESBC_CLIENT_HEADER_INVALID_SRK_NUM_ENTRY;
208 
209 	key_num = hdr->len_kr.srk_sel;
210 	if (key_num == 0 || key_num > hdr->len_kr.num_srk)
211 		return ERROR_ESBC_CLIENT_HEADER_INVALID_KEY_NUM;
212 
213 	/* Get revoc key from sfp */
214 	key_revoc_flag = get_key_revoc();
215 	ret = is_key_revoked(key_num, key_revoc_flag);
216 	if (ret)
217 		return ERROR_ESBC_CLIENT_HEADER_KEY_REVOKED;
218 
219 	size = hdr->len_kr.num_srk * sizeof(struct srk_table);
220 
221 	memcpy(&img->srk_tbl, esbc + hdr->srk_tbl_off, size);
222 
223 	for (i = 0; i < hdr->len_kr.num_srk; i++) {
224 		if (!CHECK_KEY_LEN(img->srk_tbl[i].key_len))
225 			return ERROR_ESBC_CLIENT_HEADER_INV_SRK_ENTRY_KEYLEN;
226 	}
227 
228 	img->key_len = img->srk_tbl[key_num - 1].key_len;
229 
230 	memcpy(&img->img_key, &(img->srk_tbl[key_num - 1].pkey),
231 	       img->key_len);
232 
233 	return 0;
234 }
235 #endif
236 
237 #ifndef CONFIG_ESBC_HDR_LS
238 static u32 read_validate_single_key(struct fsl_secboot_img_priv *img)
239 {
240 	struct fsl_secboot_img_hdr *hdr = &img->hdr;
241 	void *esbc = (u8 *)(uintptr_t)img->ehdrloc;
242 
243 	/* check key length */
244 	if (!CHECK_KEY_LEN(hdr->key_len))
245 		return ERROR_ESBC_CLIENT_HEADER_KEY_LEN;
246 
247 	memcpy(&img->img_key, esbc + hdr->pkey, hdr->key_len);
248 
249 	img->key_len = hdr->key_len;
250 
251 	return 0;
252 }
253 #endif /* CONFIG_ESBC_HDR_LS */
254 
255 #if defined(CONFIG_FSL_ISBC_KEY_EXT)
256 static u32 read_validate_ie_tbl(struct fsl_secboot_img_priv *img)
257 {
258 	struct fsl_secboot_img_hdr *hdr = &img->hdr;
259 	u32 ie_key_len, ie_revoc_flag, ie_num;
260 	struct ie_key_info *ie_info;
261 
262 	if (get_ie_info_addr(&img->ie_addr))
263 		return ERROR_IE_TABLE_NOT_FOUND;
264 	ie_info = (struct ie_key_info *)(uintptr_t)img->ie_addr;
265 	if (ie_info->num_keys == 0 || ie_info->num_keys > 32)
266 		return ERROR_ESBC_CLIENT_HEADER_INVALID_IE_NUM_ENTRY;
267 
268 	ie_num = hdr->ie_key_sel;
269 	if (ie_num == 0 || ie_num > ie_info->num_keys)
270 		return ERROR_ESBC_CLIENT_HEADER_INVALID_IE_KEY_NUM;
271 
272 	ie_revoc_flag = ie_info->key_revok;
273 	if ((u32)(1 << (ie_num - 1)) & ie_revoc_flag)
274 		return ERROR_ESBC_CLIENT_HEADER_IE_KEY_REVOKED;
275 
276 	ie_key_len = ie_info->ie_key_tbl[ie_num - 1].key_len;
277 
278 	if (!CHECK_KEY_LEN(ie_key_len))
279 		return ERROR_ESBC_CLIENT_HEADER_INV_IE_ENTRY_KEYLEN;
280 
281 	memcpy(&img->img_key, &(ie_info->ie_key_tbl[ie_num - 1].pkey),
282 	       ie_key_len);
283 
284 	img->key_len = ie_key_len;
285 	return 0;
286 }
287 #endif
288 
289 
290 /* This function return length of public key.*/
291 static inline u32 get_key_len(struct fsl_secboot_img_priv *img)
292 {
293 	return img->key_len;
294 }
295 
296 /*
297  * Handles the ESBC uboot client header verification failure.
298  * This  function  handles all the errors which might occur in the
299  * parsing and checking of ESBC uboot client header. It will also
300  * set the error bits in the SEC_MON.
301  */
302 static void fsl_secboot_header_verification_failure(void)
303 {
304 	struct ccsr_sfp_regs *sfp_regs = (void *)(CONFIG_SYS_SFP_ADDR);
305 
306 	/* 29th bit of OSPR is ITS */
307 	u32 its = sfp_in32(&sfp_regs->ospr) >> 2;
308 
309 	if (its == 1)
310 		set_sec_mon_state(HPSR_SSM_ST_SOFT_FAIL);
311 	else
312 		set_sec_mon_state(HPSR_SSM_ST_NON_SECURE);
313 
314 	printf("Generating reset request\n");
315 	do_reset(NULL, 0, 0, NULL);
316 	/* If reset doesn't coocur, halt execution */
317 	do_esbc_halt(NULL, 0, 0, NULL);
318 }
319 
320 /*
321  * Handles the ESBC uboot client image verification failure.
322  * This  function  handles all the errors which might occur in the
323  * public key hash comparison and signature verification of
324  * ESBC uboot client image. It will also
325  * set the error bits in the SEC_MON.
326  */
327 static void fsl_secboot_image_verification_failure(void)
328 {
329 	struct ccsr_sfp_regs *sfp_regs = (void *)(CONFIG_SYS_SFP_ADDR);
330 
331 	u32 its = (sfp_in32(&sfp_regs->ospr) & ITS_MASK) >> ITS_BIT;
332 
333 	if (its == 1) {
334 		set_sec_mon_state(HPSR_SSM_ST_SOFT_FAIL);
335 
336 		printf("Generating reset request\n");
337 		do_reset(NULL, 0, 0, NULL);
338 		/* If reset doesn't coocur, halt execution */
339 		do_esbc_halt(NULL, 0, 0, NULL);
340 
341 	} else {
342 		set_sec_mon_state(HPSR_SSM_ST_NON_SECURE);
343 	}
344 }
345 
346 static void fsl_secboot_bootscript_parse_failure(void)
347 {
348 	fsl_secboot_header_verification_failure();
349 }
350 
351 /*
352  * Handles the errors in esbc boot.
353  * This  function  handles all the errors which might occur in the
354  * esbc boot phase. It will call the appropriate api to log the
355  * errors and set the error bits in the SEC_MON.
356  */
357 void fsl_secboot_handle_error(int error)
358 {
359 	const struct fsl_secboot_errcode *e;
360 
361 	for (e = fsl_secboot_errcodes; e->errcode != ERROR_ESBC_CLIENT_MAX;
362 		e++) {
363 		if (e->errcode == error)
364 			printf("ERROR :: %x :: %s\n", error, e->name);
365 	}
366 
367 	/* If Boot Mode is secure, transition the SNVS state and issue
368 	 * reset based on type of failure and ITS setting.
369 	 * If Boot mode is non-secure, return from this function.
370 	 */
371 	if (fsl_check_boot_mode_secure() == 0)
372 		return;
373 
374 	switch (error) {
375 	case ERROR_ESBC_CLIENT_HEADER_BARKER:
376 	case ERROR_ESBC_CLIENT_HEADER_IMG_SIZE:
377 	case ERROR_ESBC_CLIENT_HEADER_KEY_LEN:
378 	case ERROR_ESBC_CLIENT_HEADER_SIG_LEN:
379 	case ERROR_ESBC_CLIENT_HEADER_KEY_LEN_NOT_TWICE_SIG_LEN:
380 	case ERROR_ESBC_CLIENT_HEADER_KEY_MOD_1:
381 	case ERROR_ESBC_CLIENT_HEADER_KEY_MOD_2:
382 	case ERROR_ESBC_CLIENT_HEADER_SIG_KEY_MOD:
383 	case ERROR_ESBC_CLIENT_HEADER_SG_ESBC_EP:
384 	case ERROR_ESBC_CLIENT_HEADER_SG_ENTIRES_BAD:
385 	case ERROR_KEY_TABLE_NOT_FOUND:
386 #ifdef CONFIG_KEY_REVOCATION
387 	case ERROR_ESBC_CLIENT_HEADER_KEY_REVOKED:
388 	case ERROR_ESBC_CLIENT_HEADER_INVALID_SRK_NUM_ENTRY:
389 	case ERROR_ESBC_CLIENT_HEADER_INVALID_KEY_NUM:
390 	case ERROR_ESBC_CLIENT_HEADER_INV_SRK_ENTRY_KEYLEN:
391 #endif
392 #if defined(CONFIG_FSL_ISBC_KEY_EXT)
393 	/*@fallthrough@*/
394 	case ERROR_ESBC_CLIENT_HEADER_IE_KEY_REVOKED:
395 	case ERROR_ESBC_CLIENT_HEADER_INVALID_IE_NUM_ENTRY:
396 	case ERROR_ESBC_CLIENT_HEADER_INVALID_IE_KEY_NUM:
397 	case ERROR_ESBC_CLIENT_HEADER_INV_IE_ENTRY_KEYLEN:
398 	case ERROR_IE_TABLE_NOT_FOUND:
399 #endif
400 		fsl_secboot_header_verification_failure();
401 		break;
402 	case ERROR_ESBC_SEC_RESET:
403 	case ERROR_ESBC_SEC_DEQ:
404 	case ERROR_ESBC_SEC_ENQ:
405 	case ERROR_ESBC_SEC_DEQ_TO:
406 	case ERROR_ESBC_SEC_JOBQ_STATUS:
407 	case ERROR_ESBC_CLIENT_HASH_COMPARE_KEY:
408 	case ERROR_ESBC_CLIENT_HASH_COMPARE_EM:
409 		fsl_secboot_image_verification_failure();
410 		break;
411 	case ERROR_ESBC_MISSING_BOOTM:
412 		fsl_secboot_bootscript_parse_failure();
413 		break;
414 	case ERROR_ESBC_WRONG_CMD:
415 	default:
416 		branch_to_self();
417 		break;
418 	}
419 }
420 
421 static void fsl_secblk_handle_error(int error)
422 {
423 	switch (error) {
424 	case ERROR_ESBC_SEC_ENQ:
425 		fsl_secboot_handle_error(ERROR_ESBC_SEC_ENQ);
426 		break;
427 	case ERROR_ESBC_SEC_DEQ:
428 		fsl_secboot_handle_error(ERROR_ESBC_SEC_DEQ);
429 		break;
430 	case ERROR_ESBC_SEC_DEQ_TO:
431 		fsl_secboot_handle_error(ERROR_ESBC_SEC_DEQ_TO);
432 		break;
433 	default:
434 		printf("Job Queue Output status %x\n", error);
435 		fsl_secboot_handle_error(ERROR_ESBC_SEC_JOBQ_STATUS);
436 		break;
437 	}
438 }
439 
440 /*
441  * Calculate hash of key obtained via offset present in ESBC uboot
442  * client hdr. This function calculates the hash of key which is obtained
443  * through offset present in ESBC uboot client header.
444  */
445 static int calc_img_key_hash(struct fsl_secboot_img_priv *img)
446 {
447 	struct hash_algo *algo;
448 	void *ctx;
449 	int i, srk = 0;
450 	int ret = 0;
451 	const char *algo_name = "sha256";
452 
453 	/* Calculate hash of the esbc key */
454 	ret = hash_progressive_lookup_algo(algo_name, &algo);
455 	if (ret)
456 		return ret;
457 
458 	ret = algo->hash_init(algo, &ctx);
459 	if (ret)
460 		return ret;
461 
462 	/* Update hash for ESBC key */
463 #ifdef CONFIG_KEY_REVOCATION
464 	if (check_srk(img)) {
465 		ret = algo->hash_update(algo, ctx,
466 		      (u8 *)(uintptr_t)(img->ehdrloc + img->hdr.srk_tbl_off),
467 		      img->hdr.len_kr.num_srk * sizeof(struct srk_table), 1);
468 		srk = 1;
469 	}
470 #endif
471 	if (!srk)
472 		ret = algo->hash_update(algo, ctx,
473 			img->img_key, img->key_len, 1);
474 	if (ret)
475 		return ret;
476 
477 	/* Copy hash at destination buffer */
478 	ret = algo->hash_finish(algo, ctx, hash_val, algo->digest_size);
479 	if (ret)
480 		return ret;
481 
482 	for (i = 0; i < SHA256_BYTES; i++)
483 		img->img_key_hash[i] = hash_val[i];
484 
485 	return 0;
486 }
487 
488 /*
489  * Calculate hash of ESBC hdr and ESBC. This function calculates the
490  * single hash of ESBC header and ESBC image. If SG flag is on, all
491  * SG entries are also hashed alongwith the complete SG table.
492  */
493 static int calc_esbchdr_esbc_hash(struct fsl_secboot_img_priv *img)
494 {
495 	struct hash_algo *algo;
496 	void *ctx;
497 	int ret = 0;
498 	int key_hash = 0;
499 	const char *algo_name = "sha256";
500 
501 	/* Calculate the hash of the ESBC */
502 	ret = hash_progressive_lookup_algo(algo_name, &algo);
503 	if (ret)
504 		return ret;
505 
506 	ret = algo->hash_init(algo, &ctx);
507 	/* Copy hash at destination buffer */
508 	if (ret)
509 		return ret;
510 
511 	/* Update hash for CSF Header */
512 	ret = algo->hash_update(algo, ctx,
513 		(u8 *)&img->hdr, sizeof(struct fsl_secboot_img_hdr), 0);
514 	if (ret)
515 		return ret;
516 
517 	/* Update the hash with that of srk table if srk flag is 1
518 	 * If IE Table is selected, key is not added in the hash
519 	 * If neither srk table nor IE key table available, add key
520 	 * from header in the hash calculation
521 	 */
522 #ifdef CONFIG_KEY_REVOCATION
523 	if (check_srk(img)) {
524 		ret = algo->hash_update(algo, ctx,
525 		      (u8 *)(uintptr_t)(img->ehdrloc + img->hdr.srk_tbl_off),
526 		      img->hdr.len_kr.num_srk * sizeof(struct srk_table), 0);
527 		key_hash = 1;
528 	}
529 #endif
530 #if defined(CONFIG_FSL_ISBC_KEY_EXT)
531 	if (!key_hash && check_ie(img))
532 		key_hash = 1;
533 #endif
534 #ifndef CONFIG_ESBC_HDR_LS
535 /* No single key support in LS ESBC header */
536 	if (!key_hash) {
537 		ret = algo->hash_update(algo, ctx,
538 			img->img_key, img->hdr.key_len, 0);
539 		key_hash = 1;
540 	}
541 #endif
542 	if (ret)
543 		return ret;
544 	if (!key_hash)
545 		return ERROR_KEY_TABLE_NOT_FOUND;
546 
547 	/* Update hash for actual Image */
548 	ret = algo->hash_update(algo, ctx,
549 		(u8 *)(*(img->img_addr_ptr)), img->img_size, 1);
550 	if (ret)
551 		return ret;
552 
553 	/* Copy hash at destination buffer */
554 	ret = algo->hash_finish(algo, ctx, hash_val, algo->digest_size);
555 	if (ret)
556 		return ret;
557 
558 	return 0;
559 }
560 
561 /*
562  * Construct encoded hash EM' wrt PKCSv1.5. This function calculates the
563  * pointers for padding, DER value and hash. And finally, constructs EM'
564  * which includes hash of complete CSF header and ESBC image. If SG flag
565  * is on, hash of SG table and entries is also included.
566  */
567 static void construct_img_encoded_hash_second(struct fsl_secboot_img_priv *img)
568 {
569 	/*
570 	 * RSA PKCSv1.5 encoding format for encoded message is below
571 	 * EM = 0x0 || 0x1 || PS || 0x0 || DER || Hash
572 	 * PS is Padding String
573 	 * DER is DER value for SHA-256
574 	 * Hash is SHA-256 hash
575 	 * *********************************************************
576 	 * representative points to first byte of EM initially and is
577 	 * filled with 0x0
578 	 * representative is incremented by 1 and second byte is filled
579 	 * with 0x1
580 	 * padding points to third byte of EM
581 	 * digest points to full length of EM - 32 bytes
582 	 * hash_id (DER value) points to 19 bytes before pDigest
583 	 * separator is one byte which separates padding and DER
584 	 */
585 
586 	size_t len;
587 	u8 *representative;
588 	u8 *padding, *digest;
589 	u8 *hash_id, *separator;
590 	int i;
591 
592 	len = (get_key_len(img) / 2) - 1;
593 	representative = img->img_encoded_hash_second;
594 	representative[0] = 0;
595 	representative[1] = 1;  /* block type 1 */
596 
597 	padding = &representative[2];
598 	digest = &representative[1] + len - 32;
599 	hash_id = digest - sizeof(hash_identifier);
600 	separator = hash_id - 1;
601 
602 	/* fill padding area pointed by padding with 0xff */
603 	memset(padding, 0xff, separator - padding);
604 
605 	/* fill byte pointed by separator */
606 	*separator = 0;
607 
608 	/* fill SHA-256 DER value  pointed by HashId */
609 	memcpy(hash_id, hash_identifier, sizeof(hash_identifier));
610 
611 	/* fill hash pointed by Digest */
612 	for (i = 0; i < SHA256_BYTES; i++)
613 		digest[i] = hash_val[i];
614 }
615 
616 /*
617  * Reads and validates the ESBC client header.
618  * This function reads key and signature from the ESBC client header.
619  * If Scatter/Gather flag is on, lengths and offsets of images
620  * present as SG entries are also read. This function also checks
621  * whether the header is valid or not.
622  */
623 static int read_validate_esbc_client_header(struct fsl_secboot_img_priv *img)
624 {
625 	struct fsl_secboot_img_hdr *hdr = &img->hdr;
626 	void *esbc = (u8 *)(uintptr_t)img->ehdrloc;
627 	u8 *k, *s;
628 	u32 ret = 0;
629 
630 	int  key_found = 0;
631 
632 	/* check barker code */
633 	if (memcmp(hdr->barker, barker_code, ESBC_BARKER_LEN))
634 		return ERROR_ESBC_CLIENT_HEADER_BARKER;
635 
636 	/* If Image Address is not passed as argument to function,
637 	 * then Address and Size must be read from the Header.
638 	 */
639 	if (*(img->img_addr_ptr) == 0) {
640 	#ifdef CONFIG_ESBC_ADDR_64BIT
641 		*(img->img_addr_ptr) = hdr->pimg64;
642 	#else
643 		*(img->img_addr_ptr) = hdr->pimg;
644 	#endif
645 	}
646 
647 	if (!hdr->img_size)
648 		return ERROR_ESBC_CLIENT_HEADER_IMG_SIZE;
649 
650 	img->img_size = hdr->img_size;
651 
652 	/* Key checking*/
653 #ifdef CONFIG_KEY_REVOCATION
654 	if (check_srk(img)) {
655 		ret = read_validate_srk_tbl(img);
656 		if (ret != 0)
657 			return ret;
658 		key_found = 1;
659 	}
660 #endif
661 
662 #if defined(CONFIG_FSL_ISBC_KEY_EXT)
663 	if (!key_found && check_ie(img)) {
664 		ret = read_validate_ie_tbl(img);
665 		if (ret != 0)
666 			return ret;
667 		key_found = 1;
668 	}
669 #endif
670 #ifndef CONFIG_ESBC_HDR_LS
671 /* Single Key Feature not available in LS ESBC Header */
672 	if (key_found == 0) {
673 		ret = read_validate_single_key(img);
674 		if (ret != 0)
675 			return ret;
676 		key_found = 1;
677 	}
678 #endif
679 	if (!key_found)
680 		return ERROR_KEY_TABLE_NOT_FOUND;
681 
682 	/* check signaure */
683 	if (get_key_len(img) == 2 * hdr->sign_len) {
684 		/* check signature length */
685 		if (!((hdr->sign_len == KEY_SIZE_BYTES / 4) ||
686 		      (hdr->sign_len == KEY_SIZE_BYTES / 2) ||
687 		      (hdr->sign_len == KEY_SIZE_BYTES)))
688 			return ERROR_ESBC_CLIENT_HEADER_SIG_LEN;
689 	} else {
690 		return ERROR_ESBC_CLIENT_HEADER_KEY_LEN_NOT_TWICE_SIG_LEN;
691 	}
692 
693 	memcpy(&img->img_sign, esbc + hdr->psign, hdr->sign_len);
694 /* No SG support in LS-CH3 */
695 #ifndef CONFIG_ESBC_HDR_LS
696 	/* No SG support */
697 	if (hdr->sg_flag)
698 		return ERROR_ESBC_CLIENT_HEADER_SG;
699 #endif
700 
701 	/* modulus most significant bit should be set */
702 	k = (u8 *)&img->img_key;
703 
704 	if ((k[0] & 0x80) == 0)
705 		return ERROR_ESBC_CLIENT_HEADER_KEY_MOD_1;
706 
707 	/* modulus value should be odd */
708 	if ((k[get_key_len(img) / 2 - 1] & 0x1) == 0)
709 		return ERROR_ESBC_CLIENT_HEADER_KEY_MOD_2;
710 
711 	/* Check signature value < modulus value */
712 	s = (u8 *)&img->img_sign;
713 
714 	if (!(memcmp(s, k, hdr->sign_len) < 0))
715 		return ERROR_ESBC_CLIENT_HEADER_SIG_KEY_MOD;
716 
717 	return ESBC_VALID_HDR;
718 }
719 
720 static inline int str2longbe(const char *p, ulong *num)
721 {
722 	char *endptr;
723 	ulong tmp;
724 
725 	if (!p) {
726 		return 0;
727 	} else {
728 		tmp = simple_strtoul(p, &endptr, 16);
729 		if (sizeof(ulong) == 4)
730 			*num = cpu_to_be32(tmp);
731 		else
732 			*num = cpu_to_be64(tmp);
733 	}
734 
735 	return *p != '\0' && *endptr == '\0';
736 }
737 /* Function to calculate the ESBC Image Hash
738  * and hash from Digital signature.
739  * The Two hash's are compared to yield the
740  * result of signature validation.
741  */
742 static int calculate_cmp_img_sig(struct fsl_secboot_img_priv *img)
743 {
744 	int ret;
745 	uint32_t key_len;
746 	struct key_prop prop;
747 #if !defined(USE_HOSTCC)
748 	struct udevice *mod_exp_dev;
749 #endif
750 	ret = calc_esbchdr_esbc_hash(img);
751 	if (ret)
752 		return ret;
753 
754 	/* Construct encoded hash EM' wrt PKCSv1.5 */
755 	construct_img_encoded_hash_second(img);
756 
757 	/* Fill prop structure for public key */
758 	memset(&prop, 0, sizeof(struct key_prop));
759 	key_len = get_key_len(img) / 2;
760 	prop.modulus = img->img_key;
761 	prop.public_exponent = img->img_key + key_len;
762 	prop.num_bits = key_len * 8;
763 	prop.exp_len = key_len;
764 
765 	ret = uclass_get_device(UCLASS_MOD_EXP, 0, &mod_exp_dev);
766 	if (ret) {
767 		printf("RSA: Can't find Modular Exp implementation\n");
768 		return -EINVAL;
769 	}
770 
771 	ret = rsa_mod_exp(mod_exp_dev, img->img_sign, img->hdr.sign_len,
772 			  &prop, img->img_encoded_hash);
773 	if (ret)
774 		return ret;
775 
776 	/*
777 	 * compare the encoded messages EM' and EM wrt RSA PKCSv1.5
778 	 * memcmp returns zero on success
779 	 * memcmp returns non-zero on failure
780 	 */
781 	ret = memcmp(&img->img_encoded_hash_second, &img->img_encoded_hash,
782 		img->hdr.sign_len);
783 
784 	if (ret)
785 		return ERROR_ESBC_CLIENT_HASH_COMPARE_EM;
786 
787 	return 0;
788 }
789 /* haddr - Address of the header of image to be validated.
790  * arg_hash_str - Option hash string. If provided, this
791  * overrides the key hash in the SFP fuses.
792  * img_addr_ptr - Optional pointer to address of image to be validated.
793  * If non zero addr, this overrides the addr of image in header,
794  * otherwise updated to image addr in header.
795  * Acts as both input and output of function.
796  * This pointer shouldn't be NULL.
797  */
798 int fsl_secboot_validate(uintptr_t haddr, char *arg_hash_str,
799 			uintptr_t *img_addr_ptr)
800 {
801 	struct ccsr_sfp_regs *sfp_regs = (void *)(CONFIG_SYS_SFP_ADDR);
802 	ulong hash[SHA256_BYTES/sizeof(ulong)];
803 	char hash_str[NUM_HEX_CHARS + 1];
804 	struct fsl_secboot_img_priv *img;
805 	struct fsl_secboot_img_hdr *hdr;
806 	void *esbc;
807 	int ret, i, hash_cmd = 0;
808 	u32 srk_hash[8];
809 
810 	if (arg_hash_str != NULL) {
811 		const char *cp = arg_hash_str;
812 		int i = 0;
813 
814 		if (*cp == '0' && *(cp + 1) == 'x')
815 			cp += 2;
816 
817 		/* The input string expected is in hex, where
818 		 * each 4 bits would be represented by a hex
819 		 * sha256 hash is 256 bits long, which would mean
820 		 * num of characters = 256 / 4
821 		 */
822 		if (strlen(cp) != SHA256_NIBBLES) {
823 			printf("%s is not a 256 bits hex string as expected\n",
824 			       arg_hash_str);
825 			return -1;
826 		}
827 
828 		for (i = 0; i < sizeof(hash)/sizeof(ulong); i++) {
829 			strncpy(hash_str, cp + (i * NUM_HEX_CHARS),
830 				NUM_HEX_CHARS);
831 			hash_str[NUM_HEX_CHARS] = '\0';
832 			if (!str2longbe(hash_str, &hash[i])) {
833 				printf("%s is not a 256 bits hex string ",
834 				       arg_hash_str);
835 				return -1;
836 			}
837 		}
838 
839 		hash_cmd = 1;
840 	}
841 
842 	img = malloc(sizeof(struct fsl_secboot_img_priv));
843 
844 	if (!img)
845 		return -1;
846 
847 	memset(img, 0, sizeof(struct fsl_secboot_img_priv));
848 
849 	/* Update the information in Private Struct */
850 	hdr = &img->hdr;
851 	img->ehdrloc = haddr;
852 	img->img_addr_ptr = img_addr_ptr;
853 	esbc = (u8 *)img->ehdrloc;
854 
855 	memcpy(hdr, esbc, sizeof(struct fsl_secboot_img_hdr));
856 
857 	/* read and validate esbc header */
858 	ret = read_validate_esbc_client_header(img);
859 
860 	if (ret != ESBC_VALID_HDR) {
861 		fsl_secboot_handle_error(ret);
862 		goto exit;
863 	}
864 
865 	/* SRKH present in SFP */
866 	for (i = 0; i < NUM_SRKH_REGS; i++)
867 		srk_hash[i] = srk_in32(&sfp_regs->srk_hash[i]);
868 
869 	/*
870 	 * Calculate hash of key obtained via offset present in
871 	 * ESBC uboot client hdr
872 	 */
873 	ret = calc_img_key_hash(img);
874 	if (ret) {
875 		fsl_secblk_handle_error(ret);
876 		goto exit;
877 	}
878 
879 	/* Compare hash obtained above with SRK hash present in SFP */
880 	if (hash_cmd)
881 		ret = memcmp(&hash, &img->img_key_hash, SHA256_BYTES);
882 	else
883 		ret = memcmp(srk_hash, img->img_key_hash, SHA256_BYTES);
884 
885 #if defined(CONFIG_FSL_ISBC_KEY_EXT)
886 	if (!hash_cmd && check_ie(img))
887 		ret = 0;
888 #endif
889 
890 	if (ret != 0) {
891 		fsl_secboot_handle_error(ERROR_ESBC_CLIENT_HASH_COMPARE_KEY);
892 		goto exit;
893 	}
894 
895 	ret = calculate_cmp_img_sig(img);
896 	if (ret) {
897 		fsl_secboot_handle_error(ret);
898 		goto exit;
899 	}
900 
901 exit:
902 	return ret;
903 }
904