xref: /rk3399_rockchip-uboot/board/freescale/common/fsl_validate.c (revision 4a97a0c91d25763d7c3af5530c5e89f53fee7643)
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_sec_mon_regs *sec_mon_regs = (void *)
305 						(CONFIG_SYS_SEC_MON_ADDR);
306 	struct ccsr_sfp_regs *sfp_regs = (void *)(CONFIG_SYS_SFP_ADDR);
307 	u32 sts = sec_mon_in32(&sec_mon_regs->hp_stat);
308 
309 	/* 29th bit of OSPR is ITS */
310 	u32 its = sfp_in32(&sfp_regs->ospr) >> 2;
311 
312 	/*
313 	 * Read the SEC_MON status register
314 	 * Read SSM_ST field
315 	 */
316 	sts = sec_mon_in32(&sec_mon_regs->hp_stat);
317 	if ((sts & HPSR_SSM_ST_MASK) == HPSR_SSM_ST_TRUST) {
318 		if (its == 1)
319 			change_sec_mon_state(HPSR_SSM_ST_TRUST,
320 					     HPSR_SSM_ST_SOFT_FAIL);
321 		else
322 			change_sec_mon_state(HPSR_SSM_ST_TRUST,
323 					     HPSR_SSM_ST_NON_SECURE);
324 	}
325 
326 	printf("Generating reset request\n");
327 	do_reset(NULL, 0, 0, NULL);
328 }
329 
330 /*
331  * Handles the ESBC uboot client image verification failure.
332  * This  function  handles all the errors which might occur in the
333  * public key hash comparison and signature verification of
334  * ESBC uboot client image. It will also
335  * set the error bits in the SEC_MON.
336  */
337 static void fsl_secboot_image_verification_failure(void)
338 {
339 	struct ccsr_sec_mon_regs *sec_mon_regs = (void *)
340 						(CONFIG_SYS_SEC_MON_ADDR);
341 	struct ccsr_sfp_regs *sfp_regs = (void *)(CONFIG_SYS_SFP_ADDR);
342 	u32 sts = sec_mon_in32(&sec_mon_regs->hp_stat);
343 
344 	u32 its = (sfp_in32(&sfp_regs->ospr) & ITS_MASK) >> ITS_BIT;
345 
346 	/*
347 	 * Read the SEC_MON status register
348 	 * Read SSM_ST field
349 	 */
350 	sts = sec_mon_in32(&sec_mon_regs->hp_stat);
351 	if ((sts & HPSR_SSM_ST_MASK) == HPSR_SSM_ST_TRUST) {
352 		if (its == 1) {
353 			change_sec_mon_state(HPSR_SSM_ST_TRUST,
354 					     HPSR_SSM_ST_SOFT_FAIL);
355 
356 			printf("Generating reset request\n");
357 			do_reset(NULL, 0, 0, NULL);
358 		} else {
359 			change_sec_mon_state(HPSR_SSM_ST_TRUST,
360 					     HPSR_SSM_ST_NON_SECURE);
361 		}
362 	}
363 }
364 
365 static void fsl_secboot_bootscript_parse_failure(void)
366 {
367 	fsl_secboot_header_verification_failure();
368 }
369 
370 /*
371  * Handles the errors in esbc boot.
372  * This  function  handles all the errors which might occur in the
373  * esbc boot phase. It will call the appropriate api to log the
374  * errors and set the error bits in the SEC_MON.
375  */
376 void fsl_secboot_handle_error(int error)
377 {
378 	const struct fsl_secboot_errcode *e;
379 
380 	for (e = fsl_secboot_errcodes; e->errcode != ERROR_ESBC_CLIENT_MAX;
381 		e++) {
382 		if (e->errcode == error)
383 			printf("ERROR :: %x :: %s\n", error, e->name);
384 	}
385 
386 	/* If Boot Mode is secure, transition the SNVS state and issue
387 	 * reset based on type of failure and ITS setting.
388 	 * If Boot mode is non-secure, return from this function.
389 	 */
390 	if (fsl_check_boot_mode_secure() == 0)
391 		return;
392 
393 	switch (error) {
394 	case ERROR_ESBC_CLIENT_HEADER_BARKER:
395 	case ERROR_ESBC_CLIENT_HEADER_IMG_SIZE:
396 	case ERROR_ESBC_CLIENT_HEADER_KEY_LEN:
397 	case ERROR_ESBC_CLIENT_HEADER_SIG_LEN:
398 	case ERROR_ESBC_CLIENT_HEADER_KEY_LEN_NOT_TWICE_SIG_LEN:
399 	case ERROR_ESBC_CLIENT_HEADER_KEY_MOD_1:
400 	case ERROR_ESBC_CLIENT_HEADER_KEY_MOD_2:
401 	case ERROR_ESBC_CLIENT_HEADER_SIG_KEY_MOD:
402 	case ERROR_ESBC_CLIENT_HEADER_SG_ESBC_EP:
403 	case ERROR_ESBC_CLIENT_HEADER_SG_ENTIRES_BAD:
404 	case ERROR_KEY_TABLE_NOT_FOUND:
405 #ifdef CONFIG_KEY_REVOCATION
406 	case ERROR_ESBC_CLIENT_HEADER_KEY_REVOKED:
407 	case ERROR_ESBC_CLIENT_HEADER_INVALID_SRK_NUM_ENTRY:
408 	case ERROR_ESBC_CLIENT_HEADER_INVALID_KEY_NUM:
409 	case ERROR_ESBC_CLIENT_HEADER_INV_SRK_ENTRY_KEYLEN:
410 #endif
411 #if defined(CONFIG_FSL_ISBC_KEY_EXT)
412 	/*@fallthrough@*/
413 	case ERROR_ESBC_CLIENT_HEADER_IE_KEY_REVOKED:
414 	case ERROR_ESBC_CLIENT_HEADER_INVALID_IE_NUM_ENTRY:
415 	case ERROR_ESBC_CLIENT_HEADER_INVALID_IE_KEY_NUM:
416 	case ERROR_ESBC_CLIENT_HEADER_INV_IE_ENTRY_KEYLEN:
417 	case ERROR_IE_TABLE_NOT_FOUND:
418 #endif
419 		fsl_secboot_header_verification_failure();
420 		break;
421 	case ERROR_ESBC_SEC_RESET:
422 	case ERROR_ESBC_SEC_DEQ:
423 	case ERROR_ESBC_SEC_ENQ:
424 	case ERROR_ESBC_SEC_DEQ_TO:
425 	case ERROR_ESBC_SEC_JOBQ_STATUS:
426 	case ERROR_ESBC_CLIENT_HASH_COMPARE_KEY:
427 	case ERROR_ESBC_CLIENT_HASH_COMPARE_EM:
428 		fsl_secboot_image_verification_failure();
429 		break;
430 	case ERROR_ESBC_MISSING_BOOTM:
431 		fsl_secboot_bootscript_parse_failure();
432 		break;
433 	case ERROR_ESBC_WRONG_CMD:
434 	default:
435 		branch_to_self();
436 		break;
437 	}
438 }
439 
440 static void fsl_secblk_handle_error(int error)
441 {
442 	switch (error) {
443 	case ERROR_ESBC_SEC_ENQ:
444 		fsl_secboot_handle_error(ERROR_ESBC_SEC_ENQ);
445 		break;
446 	case ERROR_ESBC_SEC_DEQ:
447 		fsl_secboot_handle_error(ERROR_ESBC_SEC_DEQ);
448 		break;
449 	case ERROR_ESBC_SEC_DEQ_TO:
450 		fsl_secboot_handle_error(ERROR_ESBC_SEC_DEQ_TO);
451 		break;
452 	default:
453 		printf("Job Queue Output status %x\n", error);
454 		fsl_secboot_handle_error(ERROR_ESBC_SEC_JOBQ_STATUS);
455 		break;
456 	}
457 }
458 
459 /*
460  * Calculate hash of key obtained via offset present in ESBC uboot
461  * client hdr. This function calculates the hash of key which is obtained
462  * through offset present in ESBC uboot client header.
463  */
464 static int calc_img_key_hash(struct fsl_secboot_img_priv *img)
465 {
466 	struct hash_algo *algo;
467 	void *ctx;
468 	int i, srk = 0;
469 	int ret = 0;
470 	const char *algo_name = "sha256";
471 
472 	/* Calculate hash of the esbc key */
473 	ret = hash_progressive_lookup_algo(algo_name, &algo);
474 	if (ret)
475 		return ret;
476 
477 	ret = algo->hash_init(algo, &ctx);
478 	if (ret)
479 		return ret;
480 
481 	/* Update hash for ESBC key */
482 #ifdef CONFIG_KEY_REVOCATION
483 	if (check_srk(img)) {
484 		ret = algo->hash_update(algo, ctx,
485 		      (u8 *)(uintptr_t)(img->ehdrloc + img->hdr.srk_tbl_off),
486 		      img->hdr.len_kr.num_srk * sizeof(struct srk_table), 1);
487 		srk = 1;
488 	}
489 #endif
490 	if (!srk)
491 		ret = algo->hash_update(algo, ctx,
492 			img->img_key, img->key_len, 1);
493 	if (ret)
494 		return ret;
495 
496 	/* Copy hash at destination buffer */
497 	ret = algo->hash_finish(algo, ctx, hash_val, algo->digest_size);
498 	if (ret)
499 		return ret;
500 
501 	for (i = 0; i < SHA256_BYTES; i++)
502 		img->img_key_hash[i] = hash_val[i];
503 
504 	return 0;
505 }
506 
507 /*
508  * Calculate hash of ESBC hdr and ESBC. This function calculates the
509  * single hash of ESBC header and ESBC image. If SG flag is on, all
510  * SG entries are also hashed alongwith the complete SG table.
511  */
512 static int calc_esbchdr_esbc_hash(struct fsl_secboot_img_priv *img)
513 {
514 	struct hash_algo *algo;
515 	void *ctx;
516 	int ret = 0;
517 	int key_hash = 0;
518 	const char *algo_name = "sha256";
519 
520 	/* Calculate the hash of the ESBC */
521 	ret = hash_progressive_lookup_algo(algo_name, &algo);
522 	if (ret)
523 		return ret;
524 
525 	ret = algo->hash_init(algo, &ctx);
526 	/* Copy hash at destination buffer */
527 	if (ret)
528 		return ret;
529 
530 	/* Update hash for CSF Header */
531 	ret = algo->hash_update(algo, ctx,
532 		(u8 *)&img->hdr, sizeof(struct fsl_secboot_img_hdr), 0);
533 	if (ret)
534 		return ret;
535 
536 	/* Update the hash with that of srk table if srk flag is 1
537 	 * If IE Table is selected, key is not added in the hash
538 	 * If neither srk table nor IE key table available, add key
539 	 * from header in the hash calculation
540 	 */
541 #ifdef CONFIG_KEY_REVOCATION
542 	if (check_srk(img)) {
543 		ret = algo->hash_update(algo, ctx,
544 		      (u8 *)(uintptr_t)(img->ehdrloc + img->hdr.srk_tbl_off),
545 		      img->hdr.len_kr.num_srk * sizeof(struct srk_table), 0);
546 		key_hash = 1;
547 	}
548 #endif
549 #if defined(CONFIG_FSL_ISBC_KEY_EXT)
550 	if (!key_hash && check_ie(img))
551 		key_hash = 1;
552 #endif
553 #ifndef CONFIG_ESBC_HDR_LS
554 /* No single key support in LS ESBC header */
555 	if (!key_hash) {
556 		ret = algo->hash_update(algo, ctx,
557 			img->img_key, img->hdr.key_len, 0);
558 		key_hash = 1;
559 	}
560 #endif
561 	if (ret)
562 		return ret;
563 	if (!key_hash)
564 		return ERROR_KEY_TABLE_NOT_FOUND;
565 
566 	/* Update hash for actual Image */
567 	ret = algo->hash_update(algo, ctx,
568 		(u8 *)img->img_addr, img->img_size, 1);
569 	if (ret)
570 		return ret;
571 
572 	/* Copy hash at destination buffer */
573 	ret = algo->hash_finish(algo, ctx, hash_val, algo->digest_size);
574 	if (ret)
575 		return ret;
576 
577 	return 0;
578 }
579 
580 /*
581  * Construct encoded hash EM' wrt PKCSv1.5. This function calculates the
582  * pointers for padding, DER value and hash. And finally, constructs EM'
583  * which includes hash of complete CSF header and ESBC image. If SG flag
584  * is on, hash of SG table and entries is also included.
585  */
586 static void construct_img_encoded_hash_second(struct fsl_secboot_img_priv *img)
587 {
588 	/*
589 	 * RSA PKCSv1.5 encoding format for encoded message is below
590 	 * EM = 0x0 || 0x1 || PS || 0x0 || DER || Hash
591 	 * PS is Padding String
592 	 * DER is DER value for SHA-256
593 	 * Hash is SHA-256 hash
594 	 * *********************************************************
595 	 * representative points to first byte of EM initially and is
596 	 * filled with 0x0
597 	 * representative is incremented by 1 and second byte is filled
598 	 * with 0x1
599 	 * padding points to third byte of EM
600 	 * digest points to full length of EM - 32 bytes
601 	 * hash_id (DER value) points to 19 bytes before pDigest
602 	 * separator is one byte which separates padding and DER
603 	 */
604 
605 	size_t len;
606 	u8 *representative;
607 	u8 *padding, *digest;
608 	u8 *hash_id, *separator;
609 	int i;
610 
611 	len = (get_key_len(img) / 2) - 1;
612 	representative = img->img_encoded_hash_second;
613 	representative[0] = 0;
614 	representative[1] = 1;  /* block type 1 */
615 
616 	padding = &representative[2];
617 	digest = &representative[1] + len - 32;
618 	hash_id = digest - sizeof(hash_identifier);
619 	separator = hash_id - 1;
620 
621 	/* fill padding area pointed by padding with 0xff */
622 	memset(padding, 0xff, separator - padding);
623 
624 	/* fill byte pointed by separator */
625 	*separator = 0;
626 
627 	/* fill SHA-256 DER value  pointed by HashId */
628 	memcpy(hash_id, hash_identifier, sizeof(hash_identifier));
629 
630 	/* fill hash pointed by Digest */
631 	for (i = 0; i < SHA256_BYTES; i++)
632 		digest[i] = hash_val[i];
633 }
634 
635 /*
636  * Reads and validates the ESBC client header.
637  * This function reads key and signature from the ESBC client header.
638  * If Scatter/Gather flag is on, lengths and offsets of images
639  * present as SG entries are also read. This function also checks
640  * whether the header is valid or not.
641  */
642 static int read_validate_esbc_client_header(struct fsl_secboot_img_priv *img)
643 {
644 	char buf[20];
645 	struct fsl_secboot_img_hdr *hdr = &img->hdr;
646 	void *esbc = (u8 *)(uintptr_t)img->ehdrloc;
647 	u8 *k, *s;
648 	u32 ret = 0;
649 
650 	int  key_found = 0;
651 
652 	/* check barker code */
653 	if (memcmp(hdr->barker, barker_code, ESBC_BARKER_LEN))
654 		return ERROR_ESBC_CLIENT_HEADER_BARKER;
655 
656 	/* If Image Address is not passed as argument to function,
657 	 * then Address and Size must be read from the Header.
658 	 */
659 	if (img->img_addr == 0) {
660 	#ifdef CONFIG_ESBC_ADDR_64BIT
661 		img->img_addr = hdr->pimg64;
662 	#else
663 		img->img_addr = hdr->pimg;
664 	#endif
665 	}
666 
667 	sprintf(buf, "%lx", img->img_addr);
668 	setenv("img_addr", buf);
669 
670 	if (!hdr->img_size)
671 		return ERROR_ESBC_CLIENT_HEADER_IMG_SIZE;
672 
673 	img->img_size = hdr->img_size;
674 
675 	/* Key checking*/
676 #ifdef CONFIG_KEY_REVOCATION
677 	if (check_srk(img)) {
678 		ret = read_validate_srk_tbl(img);
679 		if (ret != 0)
680 			return ret;
681 		key_found = 1;
682 	}
683 #endif
684 
685 #if defined(CONFIG_FSL_ISBC_KEY_EXT)
686 	if (!key_found && check_ie(img)) {
687 		ret = read_validate_ie_tbl(img);
688 		if (ret != 0)
689 			return ret;
690 		key_found = 1;
691 	}
692 #endif
693 #ifndef CONFIG_ESBC_HDR_LS
694 /* Single Key Feature not available in LS ESBC Header */
695 	if (key_found == 0) {
696 		ret = read_validate_single_key(img);
697 		if (ret != 0)
698 			return ret;
699 		key_found = 1;
700 	}
701 #endif
702 	if (!key_found)
703 		return ERROR_KEY_TABLE_NOT_FOUND;
704 
705 	/* check signaure */
706 	if (get_key_len(img) == 2 * hdr->sign_len) {
707 		/* check signature length */
708 		if (!((hdr->sign_len == KEY_SIZE_BYTES / 4) ||
709 		      (hdr->sign_len == KEY_SIZE_BYTES / 2) ||
710 		      (hdr->sign_len == KEY_SIZE_BYTES)))
711 			return ERROR_ESBC_CLIENT_HEADER_SIG_LEN;
712 	} else {
713 		return ERROR_ESBC_CLIENT_HEADER_KEY_LEN_NOT_TWICE_SIG_LEN;
714 	}
715 
716 	memcpy(&img->img_sign, esbc + hdr->psign, hdr->sign_len);
717 /* No SG support in LS-CH3 */
718 #ifndef CONFIG_ESBC_HDR_LS
719 	/* No SG support */
720 	if (hdr->sg_flag)
721 		return ERROR_ESBC_CLIENT_HEADER_SG;
722 #endif
723 
724 	/* modulus most significant bit should be set */
725 	k = (u8 *)&img->img_key;
726 
727 	if ((k[0] & 0x80) == 0)
728 		return ERROR_ESBC_CLIENT_HEADER_KEY_MOD_1;
729 
730 	/* modulus value should be odd */
731 	if ((k[get_key_len(img) / 2 - 1] & 0x1) == 0)
732 		return ERROR_ESBC_CLIENT_HEADER_KEY_MOD_2;
733 
734 	/* Check signature value < modulus value */
735 	s = (u8 *)&img->img_sign;
736 
737 	if (!(memcmp(s, k, hdr->sign_len) < 0))
738 		return ERROR_ESBC_CLIENT_HEADER_SIG_KEY_MOD;
739 
740 	return ESBC_VALID_HDR;
741 }
742 
743 static inline int str2longbe(const char *p, ulong *num)
744 {
745 	char *endptr;
746 	ulong tmp;
747 
748 	if (!p) {
749 		return 0;
750 	} else {
751 		tmp = simple_strtoul(p, &endptr, 16);
752 		if (sizeof(ulong) == 4)
753 			*num = cpu_to_be32(tmp);
754 		else
755 			*num = cpu_to_be64(tmp);
756 	}
757 
758 	return *p != '\0' && *endptr == '\0';
759 }
760 /* Function to calculate the ESBC Image Hash
761  * and hash from Digital signature.
762  * The Two hash's are compared to yield the
763  * result of signature validation.
764  */
765 static int calculate_cmp_img_sig(struct fsl_secboot_img_priv *img)
766 {
767 	int ret;
768 	uint32_t key_len;
769 	struct key_prop prop;
770 #if !defined(USE_HOSTCC)
771 	struct udevice *mod_exp_dev;
772 #endif
773 	ret = calc_esbchdr_esbc_hash(img);
774 	if (ret)
775 		return ret;
776 
777 	/* Construct encoded hash EM' wrt PKCSv1.5 */
778 	construct_img_encoded_hash_second(img);
779 
780 	/* Fill prop structure for public key */
781 	memset(&prop, 0, sizeof(struct key_prop));
782 	key_len = get_key_len(img) / 2;
783 	prop.modulus = img->img_key;
784 	prop.public_exponent = img->img_key + key_len;
785 	prop.num_bits = key_len * 8;
786 	prop.exp_len = key_len;
787 
788 	ret = uclass_get_device(UCLASS_MOD_EXP, 0, &mod_exp_dev);
789 	if (ret) {
790 		printf("RSA: Can't find Modular Exp implementation\n");
791 		return -EINVAL;
792 	}
793 
794 	ret = rsa_mod_exp(mod_exp_dev, img->img_sign, img->hdr.sign_len,
795 			  &prop, img->img_encoded_hash);
796 	if (ret)
797 		return ret;
798 
799 	/*
800 	 * compare the encoded messages EM' and EM wrt RSA PKCSv1.5
801 	 * memcmp returns zero on success
802 	 * memcmp returns non-zero on failure
803 	 */
804 	ret = memcmp(&img->img_encoded_hash_second, &img->img_encoded_hash,
805 		img->hdr.sign_len);
806 
807 	if (ret)
808 		return ERROR_ESBC_CLIENT_HASH_COMPARE_EM;
809 
810 	return 0;
811 }
812 
813 int fsl_secboot_validate(uintptr_t haddr, char *arg_hash_str,
814 			uintptr_t img_addr)
815 {
816 	struct ccsr_sfp_regs *sfp_regs = (void *)(CONFIG_SYS_SFP_ADDR);
817 	ulong hash[SHA256_BYTES/sizeof(ulong)];
818 	char hash_str[NUM_HEX_CHARS + 1];
819 	struct fsl_secboot_img_priv *img;
820 	struct fsl_secboot_img_hdr *hdr;
821 	void *esbc;
822 	int ret, i, hash_cmd = 0;
823 	u32 srk_hash[8];
824 
825 	if (arg_hash_str != NULL) {
826 		const char *cp = arg_hash_str;
827 		int i = 0;
828 
829 		if (*cp == '0' && *(cp + 1) == 'x')
830 			cp += 2;
831 
832 		/* The input string expected is in hex, where
833 		 * each 4 bits would be represented by a hex
834 		 * sha256 hash is 256 bits long, which would mean
835 		 * num of characters = 256 / 4
836 		 */
837 		if (strlen(cp) != SHA256_NIBBLES) {
838 			printf("%s is not a 256 bits hex string as expected\n",
839 			       arg_hash_str);
840 			return -1;
841 		}
842 
843 		for (i = 0; i < sizeof(hash)/sizeof(ulong); i++) {
844 			strncpy(hash_str, cp + (i * NUM_HEX_CHARS),
845 				NUM_HEX_CHARS);
846 			hash_str[NUM_HEX_CHARS] = '\0';
847 			if (!str2longbe(hash_str, &hash[i])) {
848 				printf("%s is not a 256 bits hex string ",
849 				       arg_hash_str);
850 				return -1;
851 			}
852 		}
853 
854 		hash_cmd = 1;
855 	}
856 
857 	img = malloc(sizeof(struct fsl_secboot_img_priv));
858 
859 	if (!img)
860 		return -1;
861 
862 	memset(img, 0, sizeof(struct fsl_secboot_img_priv));
863 
864 	/* Update the information in Private Struct */
865 	hdr = &img->hdr;
866 	img->ehdrloc = haddr;
867 	img->img_addr = img_addr;
868 	esbc = (u8 *)img->ehdrloc;
869 
870 	memcpy(hdr, esbc, sizeof(struct fsl_secboot_img_hdr));
871 
872 	/* read and validate esbc header */
873 	ret = read_validate_esbc_client_header(img);
874 
875 	if (ret != ESBC_VALID_HDR) {
876 		fsl_secboot_handle_error(ret);
877 		goto exit;
878 	}
879 
880 	/* SRKH present in SFP */
881 	for (i = 0; i < NUM_SRKH_REGS; i++)
882 		srk_hash[i] = srk_in32(&sfp_regs->srk_hash[i]);
883 
884 	/*
885 	 * Calculate hash of key obtained via offset present in
886 	 * ESBC uboot client hdr
887 	 */
888 	ret = calc_img_key_hash(img);
889 	if (ret) {
890 		fsl_secblk_handle_error(ret);
891 		goto exit;
892 	}
893 
894 	/* Compare hash obtained above with SRK hash present in SFP */
895 	if (hash_cmd)
896 		ret = memcmp(&hash, &img->img_key_hash, SHA256_BYTES);
897 	else
898 		ret = memcmp(srk_hash, img->img_key_hash, SHA256_BYTES);
899 
900 #if defined(CONFIG_FSL_ISBC_KEY_EXT)
901 	if (!hash_cmd && check_ie(img))
902 		ret = 0;
903 #endif
904 
905 	if (ret != 0) {
906 		fsl_secboot_handle_error(ERROR_ESBC_CLIENT_HASH_COMPARE_KEY);
907 		goto exit;
908 	}
909 
910 	ret = calculate_cmp_img_sig(img);
911 	if (ret) {
912 		fsl_secboot_handle_error(ret);
913 		goto exit;
914 	}
915 
916 exit:
917 	return ret;
918 }
919