summaryrefslogtreecommitdiff
path: root/board/freescale/common/fsl_validate.c
blob: 5283648a4d090df468b3487603ce542a109aa396 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
/*
 * Copyright 2015 Freescale Semiconductor, Inc.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <fsl_validate.h>
#include <fsl_secboot_err.h>
#include <fsl_sfp.h>
#include <fsl_sec.h>
#include <command.h>
#include <malloc.h>
#include <dm/uclass.h>
#include <u-boot/rsa-mod-exp.h>
#include <hash.h>
#include <fsl_secboot_err.h>
#ifndef CONFIG_MPC85xx
#include <asm/arch/immap_ls102xa.h>
#endif

#define SHA256_BITS	256
#define SHA256_BYTES	(256/8)
#define SHA256_NIBBLES	(256/4)
#define NUM_HEX_CHARS	(sizeof(ulong) * 2)

/* This array contains DER value for SHA-256 */
static const u8 hash_identifier[] = { 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60,
		0x86, 0x48, 0x01, 0x65,	0x03, 0x04, 0x02, 0x01, 0x05, 0x00,
		0x04, 0x20
		};

static u8 hash_val[SHA256_BYTES];
static const u8 barker_code[ESBC_BARKER_LEN] = { 0x68, 0x39, 0x27, 0x81 };

void branch_to_self(void) __attribute__ ((noreturn));

/*
 * This function will put core in infinite loop.
 * This will be called when the ESBC can not proceed further due
 * to some unknown errors.
 */
void branch_to_self(void)
{
	printf("Core is in infinite loop due to errors.\n");
self:
	goto self;
}

#if defined(CONFIG_FSL_ISBC_KEY_EXT)
static u32 check_ie(struct fsl_secboot_img_priv *img)
{
	if (img->hdr.ie_flag)
		return 1;

	return 0;
}

/* This function returns the CSF Header Address of uboot
 * For MPC85xx based platforms, the LAW mapping for NOR
 * flash changes in uboot code. Hence the offset needs
 * to be calculated and added to the new NOR flash base
 * address
 */
#if defined(CONFIG_MPC85xx)
int get_csf_base_addr(ulong *csf_addr, ulong *flash_base_addr)
{
	struct ccsr_gur __iomem *gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
	u32 csf_hdr_addr = in_be32(&gur->scratchrw[0]);
	u32 csf_flash_offset = csf_hdr_addr & ~(CONFIG_SYS_PBI_FLASH_BASE);
	ulong flash_addr, addr;
	int found = 0;
	int i = 0;

	for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++) {
		flash_addr = flash_info[i].start[0];
		addr = flash_info[i].start[0] + csf_flash_offset;
		if (memcmp((u8 *)addr, barker_code, ESBC_BARKER_LEN) == 0) {
			debug("Barker found on addr %lx\n", addr);
			found = 1;
			break;
		}
	}

	if (!found)
		return -1;

	*csf_addr = addr;
	*flash_base_addr = flash_addr;

	return 0;
}
#else
/* For platforms like LS1020, correct flash address is present in
 * the header. So the function reqturns flash base address as 0
 */
int get_csf_base_addr(ulong *csf_addr, ulong *flash_base_addr)
{
	struct ccsr_gur __iomem *gur = (void *)(CONFIG_SYS_FSL_GUTS_ADDR);
	u32 csf_hdr_addr = in_be32(&gur->scratchrw[0]);

	if (memcmp((u8 *)csf_hdr_addr, barker_code, ESBC_BARKER_LEN))
		return -1;

	*csf_addr = csf_hdr_addr;
	*flash_base_addr = 0;
	return 0;
}
#endif

static int get_ie_info_addr(ulong *ie_addr)
{
	struct fsl_secboot_img_hdr *hdr;
	struct fsl_secboot_sg_table *sg_tbl;
	ulong flash_base_addr, csf_addr;

	if (get_csf_base_addr(&csf_addr, &flash_base_addr))
		return -1;

	hdr = (struct fsl_secboot_img_hdr *)csf_addr;

	/* For SoC's with Trust Architecture v1 with corenet bus
	 * the sg table field in CSF header has absolute address
	 * for sg table in memory. In other Trust Architecture,
	 * this field specifies the offset of sg table from the
	 * base address of CSF Header
	 */
#if defined(CONFIG_FSL_TRUST_ARCH_v1) && defined(CONFIG_FSL_CORENET)
	sg_tbl = (struct fsl_secboot_sg_table *)
		 (((ulong)hdr->psgtable & ~(CONFIG_SYS_PBI_FLASH_BASE)) +
		  flash_base_addr);
#else
	sg_tbl = (struct fsl_secboot_sg_table *)(csf_addr +
						 (ulong)hdr->psgtable);
#endif

	/* IE Key Table is the first entry in the SG Table */
#if defined(CONFIG_MPC85xx)
	*ie_addr = (sg_tbl->src_addr & ~(CONFIG_SYS_PBI_FLASH_BASE)) +
		   flash_base_addr;
#else
	*ie_addr = sg_tbl->src_addr;
#endif

	debug("IE Table address is %lx\n", *ie_addr);
	return 0;
}

#endif

#ifdef CONFIG_KEY_REVOCATION
/* This function checks srk_table_flag in header and set/reset srk_flag.*/
static u32 check_srk(struct fsl_secboot_img_priv *img)
{
	if (img->hdr.len_kr.srk_table_flag & SRK_FLAG)
		return 1;

	return 0;
}

/* This function returns ospr's key_revoc values.*/
static u32 get_key_revoc(void)
{
	struct ccsr_sfp_regs *sfp_regs = (void *)(CONFIG_SYS_SFP_ADDR);
	return (sfp_in32(&sfp_regs->ospr) & OSPR_KEY_REVOC_MASK) >>
		OSPR_KEY_REVOC_SHIFT;
}

/* This function checks if selected key is revoked or not.*/
static u32 is_key_revoked(u32 keynum, u32 rev_flag)
{
	if (keynum == UNREVOCABLE_KEY)
		return 0;

	if ((u32)(1 << (ALIGN_REVOC_KEY - keynum)) & rev_flag)
		return 1;

	return 0;
}

/* It validates srk_table key lengths.*/
static u32 validate_srk_tbl(struct srk_table *tbl, u32 num_entries)
{
	int i = 0;
	for (i = 0; i < num_entries; i++) {
		if (!((tbl[i].key_len == 2 * KEY_SIZE_BYTES/4) ||
		      (tbl[i].key_len == 2 * KEY_SIZE_BYTES/2) ||
		      (tbl[i].key_len == 2 * KEY_SIZE_BYTES)))
			return ERROR_ESBC_CLIENT_HEADER_INV_SRK_ENTRY_KEYLEN;
	}
	return 0;
}
#endif

/* This function return length of public key.*/
static inline u32 get_key_len(struct fsl_secboot_img_priv *img)
{
	return img->key_len;
}

/*
 * Handles the ESBC uboot client header verification failure.
 * This  function  handles all the errors which might occur in the
 * parsing and checking of ESBC uboot client header. It will also
 * set the error bits in the SEC_MON.
 */
static void fsl_secboot_header_verification_failure(void)
{
	struct ccsr_sec_mon_regs *sec_mon_regs = (void *)
						(CONFIG_SYS_SEC_MON_ADDR);
	struct ccsr_sfp_regs *sfp_regs = (void *)(CONFIG_SYS_SFP_ADDR);
	u32 sts = sec_mon_in32(&sec_mon_regs->hp_stat);

	/* 29th bit of OSPR is ITS */
	u32 its = sfp_in32(&sfp_regs->ospr) >> 2;

	/*
	 * Read the SEC_MON status register
	 * Read SSM_ST field
	 */
	sts = sec_mon_in32(&sec_mon_regs->hp_stat);
	if ((sts & HPSR_SSM_ST_MASK) == HPSR_SSM_ST_TRUST) {
		if (its == 1)
			change_sec_mon_state(HPSR_SSM_ST_TRUST,
					     HPSR_SSM_ST_SOFT_FAIL);
		else
			change_sec_mon_state(HPSR_SSM_ST_TRUST,
					     HPSR_SSM_ST_NON_SECURE);
	}

	printf("Generating reset request\n");
	do_reset(NULL, 0, 0, NULL);
}

/*
 * Handles the ESBC uboot client image verification failure.
 * This  function  handles all the errors which might occur in the
 * public key hash comparison and signature verification of
 * ESBC uboot client image. It will also
 * set the error bits in the SEC_MON.
 */
static void fsl_secboot_image_verification_failure(void)
{
	struct ccsr_sec_mon_regs *sec_mon_regs = (void *)
						(CONFIG_SYS_SEC_MON_ADDR);
	struct ccsr_sfp_regs *sfp_regs = (void *)(CONFIG_SYS_SFP_ADDR);
	u32 sts = sec_mon_in32(&sec_mon_regs->hp_stat);

	u32 its = sfp_in32(&sfp_regs->ospr) & ITS_MASK >> ITS_BIT;

	/*
	 * Read the SEC_MON status register
	 * Read SSM_ST field
	 */
	sts = sec_mon_in32(&sec_mon_regs->hp_stat);
	if ((sts & HPSR_SSM_ST_MASK) == HPSR_SSM_ST_TRUST) {
		if (its == 1) {
			change_sec_mon_state(HPSR_SSM_ST_TRUST,
					     HPSR_SSM_ST_SOFT_FAIL);

			printf("Generating reset request\n");
			do_reset(NULL, 0, 0, NULL);
		} else {
			change_sec_mon_state(HPSR_SSM_ST_TRUST,
					     HPSR_SSM_ST_NON_SECURE);
		}
	}
}

static void fsl_secboot_bootscript_parse_failure(void)
{
	fsl_secboot_header_verification_failure();
}

/*
 * Handles the errors in esbc boot.
 * This  function  handles all the errors which might occur in the
 * esbc boot phase. It will call the appropriate api to log the
 * errors and set the error bits in the SEC_MON.
 */
void fsl_secboot_handle_error(int error)
{
	const struct fsl_secboot_errcode *e;

	for (e = fsl_secboot_errcodes; e->errcode != ERROR_ESBC_CLIENT_MAX;
		e++) {
		if (e->errcode == error)
			printf("ERROR :: %x :: %s\n", error, e->name);
	}

	switch (error) {
	case ERROR_ESBC_CLIENT_HEADER_BARKER:
	case ERROR_ESBC_CLIENT_HEADER_IMG_SIZE:
	case ERROR_ESBC_CLIENT_HEADER_KEY_LEN:
	case ERROR_ESBC_CLIENT_HEADER_SIG_LEN:
	case ERROR_ESBC_CLIENT_HEADER_KEY_LEN_NOT_TWICE_SIG_LEN:
	case ERROR_ESBC_CLIENT_HEADER_KEY_MOD_1:
	case ERROR_ESBC_CLIENT_HEADER_KEY_MOD_2:
	case ERROR_ESBC_CLIENT_HEADER_SIG_KEY_MOD:
	case ERROR_ESBC_CLIENT_HEADER_SG_ESBC_EP:
	case ERROR_ESBC_CLIENT_HEADER_SG_ENTIRES_BAD:
#ifdef CONFIG_KEY_REVOCATION
	case ERROR_ESBC_CLIENT_HEADER_KEY_REVOKED:
	case ERROR_ESBC_CLIENT_HEADER_INVALID_SRK_NUM_ENTRY:
	case ERROR_ESBC_CLIENT_HEADER_INVALID_KEY_NUM:
	case ERROR_ESBC_CLIENT_HEADER_INV_SRK_ENTRY_KEYLEN:
#endif
#if defined(CONFIG_FSL_ISBC_KEY_EXT)
	/*@fallthrough@*/
	case ERROR_ESBC_CLIENT_HEADER_IE_KEY_REVOKED:
	case ERROR_ESBC_CLIENT_HEADER_INVALID_IE_NUM_ENTRY:
	case ERROR_ESBC_CLIENT_HEADER_INVALID_IE_KEY_NUM:
	case ERROR_ESBC_CLIENT_HEADER_INV_IE_ENTRY_KEYLEN:
	case ERROR_IE_TABLE_NOT_FOUND:
#endif
		fsl_secboot_header_verification_failure();
		break;
	case ERROR_ESBC_SEC_RESET:
	case ERROR_ESBC_SEC_DEQ:
	case ERROR_ESBC_SEC_ENQ:
	case ERROR_ESBC_SEC_DEQ_TO:
	case ERROR_ESBC_SEC_JOBQ_STATUS:
	case ERROR_ESBC_CLIENT_HASH_COMPARE_KEY:
	case ERROR_ESBC_CLIENT_HASH_COMPARE_EM:
		fsl_secboot_image_verification_failure();
		break;
	case ERROR_ESBC_MISSING_BOOTM:
		fsl_secboot_bootscript_parse_failure();
		break;
	case ERROR_ESBC_WRONG_CMD:
	default:
		branch_to_self();
		break;
	}
}

static void fsl_secblk_handle_error(int error)
{
	switch (error) {
	case ERROR_ESBC_SEC_ENQ:
		fsl_secboot_handle_error(ERROR_ESBC_SEC_ENQ);
		break;
	case ERROR_ESBC_SEC_DEQ:
		fsl_secboot_handle_error(ERROR_ESBC_SEC_DEQ);
		break;
	case ERROR_ESBC_SEC_DEQ_TO:
		fsl_secboot_handle_error(ERROR_ESBC_SEC_DEQ_TO);
		break;
	default:
		printf("Job Queue Output status %x\n", error);
		fsl_secboot_handle_error(ERROR_ESBC_SEC_JOBQ_STATUS);
		break;
	}
}

/*
 * Calculate hash of key obtained via offset present in ESBC uboot
 * client hdr. This function calculates the hash of key which is obtained
 * through offset present in ESBC uboot client header.
 */
static int calc_img_key_hash(struct fsl_secboot_img_priv *img)
{
	struct hash_algo *algo;
	void *ctx;
	int i, srk = 0;
	int ret = 0;
	const char *algo_name = "sha256";

	/* Calculate hash of the esbc key */
	ret = hash_progressive_lookup_algo(algo_name, &algo);
	if (ret)
		return ret;

	ret = algo->hash_init(algo, &ctx);
	if (ret)
		return ret;

	/* Update hash for ESBC key */
#ifdef CONFIG_KEY_REVOCATION
	if (check_srk(img)) {
		ret = algo->hash_update(algo, ctx,
			(u8 *)(img->ehdrloc + img->hdr.srk_tbl_off),
			img->hdr.len_kr.num_srk * sizeof(struct srk_table), 1);
		srk = 1;
	}
#endif
	if (!srk)
		ret = algo->hash_update(algo, ctx,
			img->img_key, img->key_len, 1);
	if (ret)
		return ret;

	/* Copy hash at destination buffer */
	ret = algo->hash_finish(algo, ctx, hash_val, algo->digest_size);
	if (ret)
		return ret;

	for (i = 0; i < SHA256_BYTES; i++)
		img->img_key_hash[i] = hash_val[i];

	return 0;
}

/*
 * Calculate hash of ESBC hdr and ESBC. This function calculates the
 * single hash of ESBC header and ESBC image. If SG flag is on, all
 * SG entries are also hashed alongwith the complete SG table.
 */
static int calc_esbchdr_esbc_hash(struct fsl_secboot_img_priv *img)
{
	struct hash_algo *algo;
	void *ctx;
	int ret = 0;
	int key_hash = 0;
	const char *algo_name = "sha256";

	/* Calculate the hash of the ESBC */
	ret = hash_progressive_lookup_algo(algo_name, &algo);
	if (ret)
		return ret;

	ret = algo->hash_init(algo, &ctx);
	/* Copy hash at destination buffer */
	if (ret)
		return ret;

	/* Update hash for CSF Header */
	ret = algo->hash_update(algo, ctx,
		(u8 *)&img->hdr, sizeof(struct fsl_secboot_img_hdr), 0);
	if (ret)
		return ret;

	/* Update the hash with that of srk table if srk flag is 1
	 * If IE Table is selected, key is not added in the hash
	 * If neither srk table nor IE key table available, add key
	 * from header in the hash calculation
	 */
#ifdef CONFIG_KEY_REVOCATION
	if (check_srk(img)) {
		ret = algo->hash_update(algo, ctx,
			(u8 *)(img->ehdrloc + img->hdr.srk_tbl_off),
			img->hdr.len_kr.num_srk * sizeof(struct srk_table), 0);
		key_hash = 1;
	}
#endif
#if defined(CONFIG_FSL_ISBC_KEY_EXT)
	if (!key_hash && check_ie(img))
		key_hash = 1;
#endif
	if (!key_hash)
		ret = algo->hash_update(algo, ctx,
			img->img_key, img->hdr.key_len, 0);
	if (ret)
		return ret;

	/* Update hash for actual Image */
	ret = algo->hash_update(algo, ctx,
			(u8 *)img->hdr.pimg, img->hdr.img_size, 1);
	if (ret)
		return ret;

	/* Copy hash at destination buffer */
	ret = algo->hash_finish(algo, ctx, hash_val, algo->digest_size);
	if (ret)
		return ret;

	return 0;
}

/*
 * Construct encoded hash EM' wrt PKCSv1.5. This function calculates the
 * pointers for padding, DER value and hash. And finally, constructs EM'
 * which includes hash of complete CSF header and ESBC image. If SG flag
 * is on, hash of SG table and entries is also included.
 */
static void construct_img_encoded_hash_second(struct fsl_secboot_img_priv *img)
{
	/*
	 * RSA PKCSv1.5 encoding format for encoded message is below
	 * EM = 0x0 || 0x1 || PS || 0x0 || DER || Hash
	 * PS is Padding String
	 * DER is DER value for SHA-256
	 * Hash is SHA-256 hash
	 * *********************************************************
	 * representative points to first byte of EM initially and is
	 * filled with 0x0
	 * representative is incremented by 1 and second byte is filled
	 * with 0x1
	 * padding points to third byte of EM
	 * digest points to full length of EM - 32 bytes
	 * hash_id (DER value) points to 19 bytes before pDigest
	 * separator is one byte which separates padding and DER
	 */

	size_t len;
	u8 *representative;
	u8 *padding, *digest;
	u8 *hash_id, *separator;
	int i;

	len = (get_key_len(img) / 2) - 1;
	representative = img->img_encoded_hash_second;
	representative[0] = 0;
	representative[1] = 1;  /* block type 1 */

	padding = &representative[2];
	digest = &representative[1] + len - 32;
	hash_id = digest - sizeof(hash_identifier);
	separator = hash_id - 1;

	/* fill padding area pointed by padding with 0xff */
	memset(padding, 0xff, separator - padding);

	/* fill byte pointed by separator */
	*separator = 0;

	/* fill SHA-256 DER value  pointed by HashId */
	memcpy(hash_id, hash_identifier, sizeof(hash_identifier));

	/* fill hash pointed by Digest */
	for (i = 0; i < SHA256_BYTES; i++)
		digest[i] = hash_val[i];
}

/*
 * Reads and validates the ESBC client header.
 * This function reads key and signature from the ESBC client header.
 * If Scatter/Gather flag is on, lengths and offsets of images
 * present as SG entries are also read. This function also checks
 * whether the header is valid or not.
 */
static int read_validate_esbc_client_header(struct fsl_secboot_img_priv *img)
{
	char buf[20];
	struct fsl_secboot_img_hdr *hdr = &img->hdr;
	void *esbc = (u8 *)img->ehdrloc;
	u8 *k, *s;
#ifdef CONFIG_KEY_REVOCATION
	u32 ret;
	u32 key_num, key_revoc_flag, size;
#endif
#if defined(CONFIG_FSL_ISBC_KEY_EXT)
	struct ie_key_info *ie_info;
	u32 ie_num, ie_revoc_flag, ie_key_len;
#endif
	int  key_found = 0;

	/* check barker code */
	if (memcmp(hdr->barker, barker_code, ESBC_BARKER_LEN))
		return ERROR_ESBC_CLIENT_HEADER_BARKER;

	sprintf(buf, "%p", hdr->pimg);
	setenv("img_addr", buf);

	if (!hdr->img_size)
		return ERROR_ESBC_CLIENT_HEADER_IMG_SIZE;

	/* Key checking*/
#ifdef CONFIG_KEY_REVOCATION
	if (check_srk(img)) {
		if ((hdr->len_kr.num_srk == 0) ||
		    (hdr->len_kr.num_srk > MAX_KEY_ENTRIES))
			return ERROR_ESBC_CLIENT_HEADER_INVALID_SRK_NUM_ENTRY;

		key_num = hdr->len_kr.srk_sel;
		if (key_num == 0 || key_num > hdr->len_kr.num_srk)
			return ERROR_ESBC_CLIENT_HEADER_INVALID_KEY_NUM;

		/* Get revoc key from sfp */
		key_revoc_flag = get_key_revoc();
		ret = is_key_revoked(key_num, key_revoc_flag);
		if (ret)
			return ERROR_ESBC_CLIENT_HEADER_KEY_REVOKED;

		size = hdr->len_kr.num_srk * sizeof(struct srk_table);

		memcpy(&img->srk_tbl, esbc + hdr->srk_tbl_off, size);

		ret = validate_srk_tbl(img->srk_tbl, hdr->len_kr.num_srk);

		if (ret != 0)
			return ret;

		img->key_len = img->srk_tbl[key_num - 1].key_len;

		memcpy(&img->img_key, &(img->srk_tbl[key_num - 1].pkey),
		       img->key_len);

		key_found = 1;
	}
#endif

#if defined(CONFIG_FSL_ISBC_KEY_EXT)
	if (!key_found && check_ie(img)) {
		if (get_ie_info_addr(&img->ie_addr))
			return ERROR_IE_TABLE_NOT_FOUND;
		ie_info = (struct ie_key_info *)img->ie_addr;
		if (ie_info->num_keys == 0 || ie_info->num_keys > 32)
			return ERROR_ESBC_CLIENT_HEADER_INVALID_IE_NUM_ENTRY;

		ie_num = hdr->ie_key_sel;
		if (ie_num == 0 || ie_num > ie_info->num_keys)
			return ERROR_ESBC_CLIENT_HEADER_INVALID_IE_KEY_NUM;

		ie_revoc_flag = ie_info->key_revok;
		if ((u32)(1 << (ie_num - 1)) & ie_revoc_flag)
			return ERROR_ESBC_CLIENT_HEADER_IE_KEY_REVOKED;

		ie_key_len = ie_info->ie_key_tbl[ie_num - 1].key_len;

		if (!((ie_key_len == 2 * KEY_SIZE_BYTES / 4) ||
		      (ie_key_len == 2 * KEY_SIZE_BYTES / 2) ||
		      (ie_key_len == 2 * KEY_SIZE_BYTES)))
			return ERROR_ESBC_CLIENT_HEADER_INV_IE_ENTRY_KEYLEN;

		memcpy(&img->img_key, &(ie_info->ie_key_tbl[ie_num - 1].pkey),
		       ie_key_len);

		img->key_len = ie_key_len;
		key_found = 1;
	}
#endif

	if (key_found == 0) {
		/* check key length */
		if (!((hdr->key_len == 2 * KEY_SIZE_BYTES / 4) ||
		      (hdr->key_len == 2 * KEY_SIZE_BYTES / 2) ||
		      (hdr->key_len == 2 * KEY_SIZE_BYTES)))
			return ERROR_ESBC_CLIENT_HEADER_KEY_LEN;

		memcpy(&img->img_key, esbc + hdr->pkey, hdr->key_len);

		img->key_len = hdr->key_len;

		key_found = 1;
	}

	/* check signaure */
	if (get_key_len(img) == 2 * hdr->sign_len) {
		/* check signature length */
		if (!((hdr->sign_len == KEY_SIZE_BYTES / 4) ||
		      (hdr->sign_len == KEY_SIZE_BYTES / 2) ||
		      (hdr->sign_len == KEY_SIZE_BYTES)))
			return ERROR_ESBC_CLIENT_HEADER_SIG_LEN;
	} else {
		return ERROR_ESBC_CLIENT_HEADER_KEY_LEN_NOT_TWICE_SIG_LEN;
	}

	memcpy(&img->img_sign, esbc + hdr->psign, hdr->sign_len);

	/* No SG support */
	if (hdr->sg_flag)
		return ERROR_ESBC_CLIENT_HEADER_SG;

	/* modulus most significant bit should be set */
	k = (u8 *)&img->img_key;

	if ((k[0] & 0x80) == 0)
		return ERROR_ESBC_CLIENT_HEADER_KEY_MOD_1;

	/* modulus value should be odd */
	if ((k[get_key_len(img) / 2 - 1] & 0x1) == 0)
		return ERROR_ESBC_CLIENT_HEADER_KEY_MOD_2;

	/* Check signature value < modulus value */
	s = (u8 *)&img->img_sign;

	if (!(memcmp(s, k, hdr->sign_len) < 0))
		return ERROR_ESBC_CLIENT_HEADER_SIG_KEY_MOD;

	return ESBC_VALID_HDR;
}

static inline int str2longbe(const char *p, ulong *num)
{
	char *endptr;
	ulong tmp;

	if (!p) {
		return 0;
	} else {
		tmp = simple_strtoul(p, &endptr, 16);
		if (sizeof(ulong) == 4)
			*num = cpu_to_be32(tmp);
		else
			*num = cpu_to_be64(tmp);
	}

	return *p != '\0' && *endptr == '\0';
}

int fsl_secboot_validate(cmd_tbl_t *cmdtp, int flag, int argc,
		char * const argv[])
{
	struct ccsr_sfp_regs *sfp_regs = (void *)(CONFIG_SYS_SFP_ADDR);
	ulong hash[SHA256_BYTES/sizeof(ulong)];
	char hash_str[NUM_HEX_CHARS + 1];
	ulong addr = simple_strtoul(argv[1], NULL, 16);
	struct fsl_secboot_img_priv *img;
	struct fsl_secboot_img_hdr *hdr;
	void *esbc;
	int ret, i, hash_cmd = 0;
	u32 srk_hash[8];
	uint32_t key_len;
	struct key_prop prop;
#if !defined(USE_HOSTCC)
	struct udevice *mod_exp_dev;
#endif

	if (argc == 3) {
		char *cp = argv[2];
		int i = 0;

		if (*cp == '0' && *(cp + 1) == 'x')
			cp += 2;

		/* The input string expected is in hex, where
		 * each 4 bits would be represented by a hex
		 * sha256 hash is 256 bits long, which would mean
		 * num of characters = 256 / 4
		 */
		if (strlen(cp) != SHA256_NIBBLES) {
			printf("%s is not a 256 bits hex string as expected\n",
			       argv[2]);
			return -1;
		}

		for (i = 0; i < sizeof(hash)/sizeof(ulong); i++) {
			strncpy(hash_str, cp + (i * NUM_HEX_CHARS),
				NUM_HEX_CHARS);
			hash_str[NUM_HEX_CHARS] = '\0';
			if (!str2longbe(hash_str, &hash[i])) {
				printf("%s is not a 256 bits hex string ",
				       argv[2]);
				return -1;
			}
		}

		hash_cmd = 1;
	}

	img = malloc(sizeof(struct fsl_secboot_img_priv));

	if (!img)
		return -1;

	memset(img, 0, sizeof(struct fsl_secboot_img_priv));

	hdr = &img->hdr;
	img->ehdrloc = addr;
	esbc = (u8 *)img->ehdrloc;

	memcpy(hdr, esbc, sizeof(struct fsl_secboot_img_hdr));

	/* read and validate esbc header */
	ret = read_validate_esbc_client_header(img);

	if (ret != ESBC_VALID_HDR) {
		fsl_secboot_handle_error(ret);
		goto exit;
	}

	/* SRKH present in SFP */
	for (i = 0; i < NUM_SRKH_REGS; i++)
		srk_hash[i] = srk_in32(&sfp_regs->srk_hash[i]);

	/*
	 * Calculate hash of key obtained via offset present in
	 * ESBC uboot client hdr
	 */
	ret = calc_img_key_hash(img);
	if (ret) {
		fsl_secblk_handle_error(ret);
		goto exit;
	}

	/* Compare hash obtained above with SRK hash present in SFP */
	if (hash_cmd)
		ret = memcmp(&hash, &img->img_key_hash, SHA256_BYTES);
	else
		ret = memcmp(srk_hash, img->img_key_hash, SHA256_BYTES);

#if defined(CONFIG_FSL_ISBC_KEY_EXT)
	if (!hash_cmd && check_ie(img))
		ret = 0;
#endif

	if (ret != 0) {
		fsl_secboot_handle_error(ERROR_ESBC_CLIENT_HASH_COMPARE_KEY);
		goto exit;
	}

	ret = calc_esbchdr_esbc_hash(img);
	if (ret) {
		fsl_secblk_handle_error(ret);
		goto exit;
	}

	/* Construct encoded hash EM' wrt PKCSv1.5 */
	construct_img_encoded_hash_second(img);

	/* Fill prop structure for public key */
	memset(&prop, 0, sizeof(struct key_prop));
	key_len = get_key_len(img) / 2;
	prop.modulus = img->img_key;
	prop.public_exponent = img->img_key + key_len;
	prop.num_bits = key_len * 8;
	prop.exp_len = key_len;

	ret = uclass_get_device(UCLASS_MOD_EXP, 0, &mod_exp_dev);
	if (ret) {
		printf("RSA: Can't find Modular Exp implementation\n");
		return -EINVAL;
	}

	ret = rsa_mod_exp(mod_exp_dev, img->img_sign, img->hdr.sign_len,
			  &prop, img->img_encoded_hash);
	if (ret) {
		fsl_secblk_handle_error(ret);
		goto exit;
	}

	/*
	 * compare the encoded messages EM' and EM wrt RSA PKCSv1.5
	 * memcmp returns zero on success
	 * memcmp returns non-zero on failure
	 */
	ret = memcmp(&img->img_encoded_hash_second, &img->img_encoded_hash,
		img->hdr.sign_len);

	if (ret) {
		fsl_secboot_handle_error(ERROR_ESBC_CLIENT_HASH_COMPARE_EM);
		goto exit;
	}

	printf("esbc_validate command successful\n");

exit:
	return 0;
}