summaryrefslogtreecommitdiffstats
path: root/drivers/mmc/rpmb.c
blob: 9d0b8bc0c8f9b41fd91185729e87c3777e8c7a23 (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
/*
 * Copyright 2014, Staubli Faverges
 * Pierre Aubert
 *
 * eMMC- Replay Protected Memory Block
 * According to JEDEC Standard No. 84-A441
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <config.h>
#include <common.h>
#include <mmc.h>
#include <u-boot/sha256.h>
#include "mmc_private.h"

/* Request codes */
#define RPMB_REQ_KEY		1
#define RPMB_REQ_WCOUNTER	2
#define RPMB_REQ_WRITE_DATA	3
#define RPMB_REQ_READ_DATA	4
#define RPMB_REQ_STATUS		5

/* Response code */
#define RPMB_RESP_KEY		0x0100
#define RPMB_RESP_WCOUNTER	0x0200
#define RPMB_RESP_WRITE_DATA	0x0300
#define RPMB_RESP_READ_DATA	0x0400

/* Error codes */
#define RPMB_OK			0
#define RPMB_ERR_GENERAL	1
#define RPMB_ERR_AUTH	2
#define RPMB_ERR_COUNTER	3
#define RPMB_ERR_ADDRESS	4
#define RPMB_ERR_WRITE		5
#define RPMB_ERR_READ		6
#define RPMB_ERR_KEY		7
#define RPMB_ERR_CNT_EXPIRED	0x80
#define RPMB_ERR_MSK		0x7

/* Sizes of RPMB data frame */
#define RPMB_SZ_STUFF		196
#define RPMB_SZ_MAC		32
#define RPMB_SZ_DATA		256
#define RPMB_SZ_NONCE		16

#define SHA256_BLOCK_SIZE	64

/* Error messages */
static const char * const rpmb_err_msg[] = {
	"",
	"General failure",
	"Authentication failure",
	"Counter failure",
	"Address failure",
	"Write failure",
	"Read failure",
	"Authentication key not yet programmed",
};


/* Structure of RPMB data frame. */
struct s_rpmb {
	unsigned char stuff[RPMB_SZ_STUFF];
	unsigned char mac[RPMB_SZ_MAC];
	unsigned char data[RPMB_SZ_DATA];
	unsigned char nonce[RPMB_SZ_NONCE];
	unsigned long write_counter;
	unsigned short address;
	unsigned short block_count;
	unsigned short result;
	unsigned short request;
};

static int mmc_set_blockcount(struct mmc *mmc, unsigned int blockcount,
			      bool is_rel_write)
{
	struct mmc_cmd cmd = {0};

	cmd.cmdidx = MMC_CMD_SET_BLOCK_COUNT;
	cmd.cmdarg = blockcount & 0x0000FFFF;
	if (is_rel_write)
		cmd.cmdarg |= 1 << 31;
	cmd.resp_type = MMC_RSP_R1;

	return mmc_send_cmd(mmc, &cmd, NULL);
}
static int mmc_rpmb_request(struct mmc *mmc, const struct s_rpmb *s,
			    unsigned int count, bool is_rel_write)
{
	struct mmc_cmd cmd = {0};
	struct mmc_data data;
	int ret;

	ret = mmc_set_blockcount(mmc, count, is_rel_write);
	if (ret) {
#ifdef CONFIG_MMC_RPMB_TRACE
		printf("%s:mmc_set_blockcount-> %d\n", __func__, ret);
#endif
		return 1;
	}

	cmd.cmdidx = MMC_CMD_WRITE_MULTIPLE_BLOCK;
	cmd.cmdarg = 0;
	cmd.resp_type = MMC_RSP_R1b;

	data.src = (const char *)s;
	data.blocks = 1;
	data.blocksize = MMC_MAX_BLOCK_LEN;
	data.flags = MMC_DATA_WRITE;

	ret = mmc_send_cmd(mmc, &cmd, &data);
	if (ret) {
#ifdef CONFIG_MMC_RPMB_TRACE
		printf("%s:mmc_send_cmd-> %d\n", __func__, ret);
#endif
		return 1;
	}
	return 0;
}
static int mmc_rpmb_response(struct mmc *mmc, struct s_rpmb *s,
			     unsigned short expected)
{
	struct mmc_cmd cmd = {0};
	struct mmc_data data;
	int ret;

	ret = mmc_set_blockcount(mmc, 1, false);
	if (ret) {
#ifdef CONFIG_MMC_RPMB_TRACE
		printf("%s:mmc_set_blockcount-> %d\n", __func__, ret);
#endif
		return -1;
	}
	cmd.cmdidx = MMC_CMD_READ_MULTIPLE_BLOCK;
	cmd.cmdarg = 0;
	cmd.resp_type = MMC_RSP_R1;

	data.dest = (char *)s;
	data.blocks = 1;
	data.blocksize = MMC_MAX_BLOCK_LEN;
	data.flags = MMC_DATA_READ;

	ret = mmc_send_cmd(mmc, &cmd, &data);
	if (ret) {
#ifdef CONFIG_MMC_RPMB_TRACE
		printf("%s:mmc_send_cmd-> %d\n", __func__, ret);
#endif
		return -1;
	}
	/* Check the response and the status */
	if (be16_to_cpu(s->request) != expected) {
#ifdef CONFIG_MMC_RPMB_TRACE
		printf("%s:response= %x\n", __func__,
		       be16_to_cpu(s->request));
#endif
		return -1;
	}
	ret = be16_to_cpu(s->result);
	if (ret) {
		printf("%s %s\n", rpmb_err_msg[ret & RPMB_ERR_MSK],
		       (ret & RPMB_ERR_CNT_EXPIRED) ?
		       "Write counter has expired" : "");
	}

	/* Return the status of the command */
	return ret;
}
static int mmc_rpmb_status(struct mmc *mmc, unsigned short expected)
{
	ALLOC_CACHE_ALIGN_BUFFER(struct s_rpmb, rpmb_frame, 1);

	memset(rpmb_frame, 0, sizeof(struct s_rpmb));
	rpmb_frame->request = cpu_to_be16(RPMB_REQ_STATUS);
	if (mmc_rpmb_request(mmc, rpmb_frame, 1, false))
		return -1;

	/* Read the result */
	return mmc_rpmb_response(mmc, rpmb_frame, expected);
}
static void rpmb_hmac(unsigned char *key, unsigned char *buff, int len,
		      unsigned char *output)
{
	sha256_context ctx;
	int i;
	unsigned char k_ipad[SHA256_BLOCK_SIZE];
	unsigned char k_opad[SHA256_BLOCK_SIZE];

	sha256_starts(&ctx);

	/* According to RFC 4634, the HMAC transform looks like:
	   SHA(K XOR opad, SHA(K XOR ipad, text))

	   where K is an n byte key.
	   ipad is the byte 0x36 repeated blocksize times
	   opad is the byte 0x5c repeated blocksize times
	   and text is the data being protected.
	*/

	for (i = 0; i < RPMB_SZ_MAC; i++) {
		k_ipad[i] = key[i] ^ 0x36;
		k_opad[i] = key[i] ^ 0x5c;
	}
	/* remaining pad bytes are '\0' XOR'd with ipad and opad values */
	for ( ; i < SHA256_BLOCK_SIZE; i++) {
		k_ipad[i] = 0x36;
		k_opad[i] = 0x5c;
	}
	sha256_update(&ctx, k_ipad, SHA256_BLOCK_SIZE);
	sha256_update(&ctx, buff, len);
	sha256_finish(&ctx, output);

	/* Init context for second pass */
	sha256_starts(&ctx);

	/* start with outer pad */
	sha256_update(&ctx, k_opad, SHA256_BLOCK_SIZE);

	/* then results of 1st hash */
	sha256_update(&ctx, output, RPMB_SZ_MAC);

	/* finish up 2nd pass */
	sha256_finish(&ctx, output);
}
int mmc_rpmb_get_counter(struct mmc *mmc, unsigned long *pcounter)
{
	int ret;
	ALLOC_CACHE_ALIGN_BUFFER(struct s_rpmb, rpmb_frame, 1);

	/* Fill the request */
	memset(rpmb_frame, 0, sizeof(struct s_rpmb));
	rpmb_frame->request = cpu_to_be16(RPMB_REQ_WCOUNTER);
	if (mmc_rpmb_request(mmc, rpmb_frame, 1, false))
		return -1;

	/* Read the result */
	ret = mmc_rpmb_response(mmc, rpmb_frame, RPMB_RESP_WCOUNTER);
	if (ret)
		return ret;

	*pcounter = be32_to_cpu(rpmb_frame->write_counter);
	return 0;
}
int mmc_rpmb_set_key(struct mmc *mmc, void *key)
{
	ALLOC_CACHE_ALIGN_BUFFER(struct s_rpmb, rpmb_frame, 1);
	/* Fill the request */
	memset(rpmb_frame, 0, sizeof(struct s_rpmb));
	rpmb_frame->request = cpu_to_be16(RPMB_REQ_KEY);
	memcpy(rpmb_frame->mac, key, RPMB_SZ_MAC);

	if (mmc_rpmb_request(mmc, rpmb_frame, 1, true))
		return -1;

	/* read the operation status */
	return mmc_rpmb_status(mmc, RPMB_RESP_KEY);
}
int mmc_rpmb_read(struct mmc *mmc, void *addr, unsigned short blk,
		  unsigned short cnt, unsigned char *key)
{
	ALLOC_CACHE_ALIGN_BUFFER(struct s_rpmb, rpmb_frame, 1);
	int i;

	for (i = 0; i < cnt; i++) {
		/* Fill the request */
		memset(rpmb_frame, 0, sizeof(struct s_rpmb));
		rpmb_frame->address = cpu_to_be16(blk + i);
		rpmb_frame->request = cpu_to_be16(RPMB_REQ_READ_DATA);
		if (mmc_rpmb_request(mmc, rpmb_frame, 1, false))
			break;

		/* Read the result */
		if (mmc_rpmb_response(mmc, rpmb_frame, RPMB_RESP_READ_DATA))
			break;

		/* Check the HMAC if key is provided */
		if (key) {
			unsigned char ret_hmac[RPMB_SZ_MAC];

			rpmb_hmac(key, rpmb_frame->data, 284, ret_hmac);
			if (memcmp(ret_hmac, rpmb_frame->mac, RPMB_SZ_MAC)) {
				printf("MAC error on block #%d\n", i);
				break;
			}
		}
		/* Copy data */
		memcpy(addr + i * RPMB_SZ_DATA, rpmb_frame->data, RPMB_SZ_DATA);
	}
	return i;
}
int mmc_rpmb_write(struct mmc *mmc, void *addr, unsigned short blk,
		  unsigned short cnt, unsigned char *key)
{
	ALLOC_CACHE_ALIGN_BUFFER(struct s_rpmb, rpmb_frame, 1);
	unsigned long wcount;
	int i;

	for (i = 0; i < cnt; i++) {
		if (mmc_rpmb_get_counter(mmc, &wcount)) {
			printf("Cannot read RPMB write counter\n");
			break;
		}

		/* Fill the request */
		memset(rpmb_frame, 0, sizeof(struct s_rpmb));
		memcpy(rpmb_frame->data, addr + i * RPMB_SZ_DATA, RPMB_SZ_DATA);
		rpmb_frame->address = cpu_to_be16(blk + i);
		rpmb_frame->block_count = cpu_to_be16(1);
		rpmb_frame->write_counter = cpu_to_be32(wcount);
		rpmb_frame->request = cpu_to_be16(RPMB_REQ_WRITE_DATA);
		/* Computes HMAC */
		rpmb_hmac(key, rpmb_frame->data, 284, rpmb_frame->mac);

		if (mmc_rpmb_request(mmc, rpmb_frame, 1, true))
			break;

		/* Get status */
		if (mmc_rpmb_status(mmc, RPMB_RESP_WRITE_DATA))
			break;
	}
	return i;
}
OpenPOWER on IntegriCloud