1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2013
4 * Reinhard Pfau, Guntermann & Drunck GmbH, reinhard.pfau@gdsys.cc
5 */
6
7 #include <common.h>
8 #include <malloc.h>
9 #include <fs.h>
10 #include <i2c.h>
11 #include <mmc.h>
12 #include <tpm-v1.h>
13 #include <u-boot/sha1.h>
14 #include <asm/byteorder.h>
15 #include <asm/unaligned.h>
16 #include <pca9698.h>
17
18 #include "hre.h"
19
20 /* other constants */
21 enum {
22 ESDHC_BOOT_IMAGE_SIG_OFS = 0x40,
23 ESDHC_BOOT_IMAGE_SIZE_OFS = 0x48,
24 ESDHC_BOOT_IMAGE_ADDR_OFS = 0x50,
25 ESDHC_BOOT_IMAGE_TARGET_OFS = 0x58,
26 ESDHC_BOOT_IMAGE_ENTRY_OFS = 0x60,
27 };
28
29 enum {
30 I2C_SOC_0 = 0,
31 I2C_SOC_1 = 1,
32 };
33
34 enum access_mode {
35 HREG_NONE = 0,
36 HREG_RD = 1,
37 HREG_WR = 2,
38 HREG_RDWR = 3,
39 };
40
41 /* register constants */
42 enum {
43 FIX_HREG_DEVICE_ID_HASH = 0,
44 FIX_HREG_UNUSED1 = 1,
45 FIX_HREG_UNUSED2 = 2,
46 FIX_HREG_VENDOR = 3,
47 COUNT_FIX_HREGS
48 };
49
50 static struct h_reg pcr_hregs[24];
51 static struct h_reg fix_hregs[COUNT_FIX_HREGS];
52 static struct h_reg var_hregs[8];
53
54 /* hre opcodes */
55 enum {
56 /* opcodes w/o data */
57 HRE_NOP = 0x00,
58 HRE_SYNC = HRE_NOP,
59 HRE_CHECK0 = 0x01,
60 /* opcodes w/o data, w/ sync dst */
61 /* opcodes w/ data */
62 HRE_LOAD = 0x81,
63 /* opcodes w/data, w/sync dst */
64 HRE_XOR = 0xC1,
65 HRE_AND = 0xC2,
66 HRE_OR = 0xC3,
67 HRE_EXTEND = 0xC4,
68 HRE_LOADKEY = 0xC5,
69 };
70
71 /* hre errors */
72 enum {
73 HRE_E_OK = 0,
74 HRE_E_TPM_FAILURE,
75 HRE_E_INVALID_HREG,
76 };
77
78 static uint64_t device_id;
79 static uint64_t device_cl;
80 static uint64_t device_type;
81
82 static uint32_t platform_key_handle;
83
84 static uint32_t hre_tpm_err;
85 static int hre_err = HRE_E_OK;
86
87 #define IS_PCR_HREG(spec) ((spec) & 0x20)
88 #define IS_FIX_HREG(spec) (((spec) & 0x38) == 0x08)
89 #define IS_VAR_HREG(spec) (((spec) & 0x38) == 0x10)
90 #define HREG_IDX(spec) ((spec) & (IS_PCR_HREG(spec) ? 0x1f : 0x7))
91
92 static const uint8_t vendor[] = "Guntermann & Drunck";
93
94 /**
95 * @brief get the size of a given (TPM) NV area
96 * @param tpm TPM device
97 * @param index NV index of the area to get size for
98 * @param size pointer to the size
99 * @return 0 on success, != 0 on error
100 */
get_tpm_nv_size(struct udevice * tpm,uint32_t index,uint32_t * size)101 static int get_tpm_nv_size(struct udevice *tpm, uint32_t index, uint32_t *size)
102 {
103 uint32_t err;
104 uint8_t info[72];
105 uint8_t *ptr;
106 uint16_t v16;
107
108 err = tpm_get_capability(tpm, TPM_CAP_NV_INDEX, index,
109 info, sizeof(info));
110 if (err) {
111 printf("tpm_get_capability(CAP_NV_INDEX, %08x) failed: %u\n",
112 index, err);
113 return 1;
114 }
115
116 /* skip tag and nvIndex */
117 ptr = info + 6;
118 /* skip 2 pcr info fields */
119 v16 = get_unaligned_be16(ptr);
120 ptr += 2 + v16 + 1 + 20;
121 v16 = get_unaligned_be16(ptr);
122 ptr += 2 + v16 + 1 + 20;
123 /* skip permission and flags */
124 ptr += 6 + 3;
125
126 *size = get_unaligned_be32(ptr);
127 return 0;
128 }
129
130 /**
131 * @brief search for a key by usage auth and pub key hash.
132 * @param tpm TPM device
133 * @param auth usage auth of the key to search for
134 * @param pubkey_digest (SHA1) hash of the pub key structure of the key
135 * @param[out] handle the handle of the key iff found
136 * @return 0 if key was found in TPM; != 0 if not.
137 */
find_key(struct udevice * tpm,const uint8_t auth[20],const uint8_t pubkey_digest[20],uint32_t * handle)138 static int find_key(struct udevice *tpm, const uint8_t auth[20],
139 const uint8_t pubkey_digest[20], uint32_t *handle)
140 {
141 uint16_t key_count;
142 uint32_t key_handles[10];
143 uint8_t buf[288];
144 uint8_t *ptr;
145 uint32_t err;
146 uint8_t digest[20];
147 size_t buf_len;
148 unsigned int i;
149
150 /* fetch list of already loaded keys in the TPM */
151 err = tpm_get_capability(tpm, TPM_CAP_HANDLE, TPM_RT_KEY, buf,
152 sizeof(buf));
153 if (err)
154 return -1;
155 key_count = get_unaligned_be16(buf);
156 ptr = buf + 2;
157 for (i = 0; i < key_count; ++i, ptr += 4)
158 key_handles[i] = get_unaligned_be32(ptr);
159
160 /* now search a(/ the) key which we can access with the given auth */
161 for (i = 0; i < key_count; ++i) {
162 buf_len = sizeof(buf);
163 err = tpm_get_pub_key_oiap(tpm, key_handles[i], auth, buf,
164 &buf_len);
165 if (err && err != TPM_AUTHFAIL)
166 return -1;
167 if (err)
168 continue;
169 sha1_csum(buf, buf_len, digest);
170 if (!memcmp(digest, pubkey_digest, 20)) {
171 *handle = key_handles[i];
172 return 0;
173 }
174 }
175 return 1;
176 }
177
178 /**
179 * @brief read CCDM common data from TPM NV
180 * @param tpm TPM device
181 * @return 0 if CCDM common data was found and read, !=0 if something failed.
182 */
read_common_data(struct udevice * tpm)183 static int read_common_data(struct udevice *tpm)
184 {
185 uint32_t size = 0;
186 uint32_t err;
187 uint8_t buf[256];
188 sha1_context ctx;
189
190 if (get_tpm_nv_size(tpm, NV_COMMON_DATA_INDEX, &size) ||
191 size < NV_COMMON_DATA_MIN_SIZE)
192 return 1;
193 err = tpm_nv_read_value(tpm, NV_COMMON_DATA_INDEX,
194 buf, min(sizeof(buf), size));
195 if (err) {
196 printf("tpm_nv_read_value() failed: %u\n", err);
197 return 1;
198 }
199
200 device_id = get_unaligned_be64(buf);
201 device_cl = get_unaligned_be64(buf + 8);
202 device_type = get_unaligned_be64(buf + 16);
203
204 sha1_starts(&ctx);
205 sha1_update(&ctx, buf, 24);
206 sha1_finish(&ctx, fix_hregs[FIX_HREG_DEVICE_ID_HASH].digest);
207 fix_hregs[FIX_HREG_DEVICE_ID_HASH].valid = true;
208
209 platform_key_handle = get_unaligned_be32(buf + 24);
210
211 return 0;
212 }
213
214 /**
215 * @brief get pointer to hash register by specification
216 * @param spec specification of a hash register
217 * @return pointer to hash register or NULL if @a spec does not qualify a
218 * valid hash register; NULL else.
219 */
get_hreg(uint8_t spec)220 static struct h_reg *get_hreg(uint8_t spec)
221 {
222 uint8_t idx;
223
224 idx = HREG_IDX(spec);
225 if (IS_FIX_HREG(spec)) {
226 if (idx < ARRAY_SIZE(fix_hregs))
227 return fix_hregs + idx;
228 hre_err = HRE_E_INVALID_HREG;
229 } else if (IS_PCR_HREG(spec)) {
230 if (idx < ARRAY_SIZE(pcr_hregs))
231 return pcr_hregs + idx;
232 hre_err = HRE_E_INVALID_HREG;
233 } else if (IS_VAR_HREG(spec)) {
234 if (idx < ARRAY_SIZE(var_hregs))
235 return var_hregs + idx;
236 hre_err = HRE_E_INVALID_HREG;
237 }
238 return NULL;
239 }
240
241 /**
242 * @brief get pointer of a hash register by specification and usage.
243 * @param tpm TPM device
244 * @param spec specification of a hash register
245 * @param mode access mode (read or write or read/write)
246 * @return pointer to hash register if found and valid; NULL else.
247 *
248 * This func uses @a get_reg() to determine the hash register for a given spec.
249 * If a register is found it is validated according to the desired access mode.
250 * The value of automatic registers (PCR register and fixed registers) is
251 * loaded or computed on read access.
252 */
access_hreg(struct udevice * tpm,uint8_t spec,enum access_mode mode)253 static struct h_reg *access_hreg(struct udevice *tpm, uint8_t spec,
254 enum access_mode mode)
255 {
256 struct h_reg *result;
257
258 result = get_hreg(spec);
259 if (!result)
260 return NULL;
261
262 if (mode & HREG_WR) {
263 if (IS_FIX_HREG(spec)) {
264 hre_err = HRE_E_INVALID_HREG;
265 return NULL;
266 }
267 }
268 if (mode & HREG_RD) {
269 if (!result->valid) {
270 if (IS_PCR_HREG(spec)) {
271 hre_tpm_err = tpm_pcr_read(tpm, HREG_IDX(spec),
272 result->digest, 20);
273 result->valid = (hre_tpm_err == TPM_SUCCESS);
274 } else if (IS_FIX_HREG(spec)) {
275 switch (HREG_IDX(spec)) {
276 case FIX_HREG_DEVICE_ID_HASH:
277 read_common_data(tpm);
278 break;
279 case FIX_HREG_VENDOR:
280 memcpy(result->digest, vendor, 20);
281 result->valid = true;
282 break;
283 }
284 } else {
285 result->valid = true;
286 }
287 }
288 if (!result->valid) {
289 hre_err = HRE_E_INVALID_HREG;
290 return NULL;
291 }
292 }
293
294 return result;
295 }
296
compute_and(void * _dst,const void * _src,size_t n)297 static void *compute_and(void *_dst, const void *_src, size_t n)
298 {
299 uint8_t *dst = _dst;
300 const uint8_t *src = _src;
301 size_t i;
302
303 for (i = n; i-- > 0; )
304 *dst++ &= *src++;
305
306 return _dst;
307 }
308
compute_or(void * _dst,const void * _src,size_t n)309 static void *compute_or(void *_dst, const void *_src, size_t n)
310 {
311 uint8_t *dst = _dst;
312 const uint8_t *src = _src;
313 size_t i;
314
315 for (i = n; i-- > 0; )
316 *dst++ |= *src++;
317
318 return _dst;
319 }
320
compute_xor(void * _dst,const void * _src,size_t n)321 static void *compute_xor(void *_dst, const void *_src, size_t n)
322 {
323 uint8_t *dst = _dst;
324 const uint8_t *src = _src;
325 size_t i;
326
327 for (i = n; i-- > 0; )
328 *dst++ ^= *src++;
329
330 return _dst;
331 }
332
compute_extend(void * _dst,const void * _src,size_t n)333 static void *compute_extend(void *_dst, const void *_src, size_t n)
334 {
335 uint8_t digest[20];
336 sha1_context ctx;
337
338 sha1_starts(&ctx);
339 sha1_update(&ctx, _dst, n);
340 sha1_update(&ctx, _src, n);
341 sha1_finish(&ctx, digest);
342 memcpy(_dst, digest, min(n, sizeof(digest)));
343
344 return _dst;
345 }
346
hre_op_loadkey(struct udevice * tpm,struct h_reg * src_reg,struct h_reg * dst_reg,const void * key,size_t key_size)347 static int hre_op_loadkey(struct udevice *tpm, struct h_reg *src_reg,
348 struct h_reg *dst_reg, const void *key,
349 size_t key_size)
350 {
351 uint32_t parent_handle;
352 uint32_t key_handle;
353
354 if (!src_reg || !dst_reg || !src_reg->valid || !dst_reg->valid)
355 return -1;
356 if (find_key(tpm, src_reg->digest, dst_reg->digest, &parent_handle))
357 return -1;
358 hre_tpm_err = tpm_load_key2_oiap(tpm, parent_handle, key, key_size,
359 src_reg->digest, &key_handle);
360 if (hre_tpm_err) {
361 hre_err = HRE_E_TPM_FAILURE;
362 return -1;
363 }
364
365 return 0;
366 }
367
368 /**
369 * @brief executes the next opcode on the hash register engine.
370 * @param tpm TPM device
371 * @param[in,out] ip pointer to the opcode (instruction pointer)
372 * @param[in,out] code_size (remaining) size of the code
373 * @return new instruction pointer on success, NULL on error.
374 */
hre_execute_op(struct udevice * tpm,const uint8_t ** ip,size_t * code_size)375 static const uint8_t *hre_execute_op(struct udevice *tpm, const uint8_t **ip,
376 size_t *code_size)
377 {
378 bool dst_modified = false;
379 uint32_t ins;
380 uint8_t opcode;
381 uint8_t src_spec;
382 uint8_t dst_spec;
383 uint16_t data_size;
384 struct h_reg *src_reg, *dst_reg;
385 uint8_t buf[20];
386 const uint8_t *src_buf, *data;
387 uint8_t *ptr;
388 int i;
389 void * (*bin_func)(void *, const void *, size_t);
390
391 if (*code_size < 4)
392 return NULL;
393
394 ins = get_unaligned_be32(*ip);
395 opcode = **ip;
396 data = *ip + 4;
397 src_spec = (ins >> 18) & 0x3f;
398 dst_spec = (ins >> 12) & 0x3f;
399 data_size = (ins & 0x7ff);
400
401 debug("HRE: ins=%08x (op=%02x, s=%02x, d=%02x, L=%d)\n", ins,
402 opcode, src_spec, dst_spec, data_size);
403
404 if ((opcode & 0x80) && (data_size + 4) > *code_size)
405 return NULL;
406
407 src_reg = access_hreg(tpm, src_spec, HREG_RD);
408 if (hre_err || hre_tpm_err)
409 return NULL;
410 dst_reg = access_hreg(tpm, dst_spec,
411 (opcode & 0x40) ? HREG_RDWR : HREG_WR);
412 if (hre_err || hre_tpm_err)
413 return NULL;
414
415 switch (opcode) {
416 case HRE_NOP:
417 goto end;
418 case HRE_CHECK0:
419 if (src_reg) {
420 for (i = 0; i < 20; ++i) {
421 if (src_reg->digest[i])
422 return NULL;
423 }
424 }
425 break;
426 case HRE_LOAD:
427 bin_func = memcpy;
428 goto do_bin_func;
429 case HRE_XOR:
430 bin_func = compute_xor;
431 goto do_bin_func;
432 case HRE_AND:
433 bin_func = compute_and;
434 goto do_bin_func;
435 case HRE_OR:
436 bin_func = compute_or;
437 goto do_bin_func;
438 case HRE_EXTEND:
439 bin_func = compute_extend;
440 do_bin_func:
441 if (!dst_reg)
442 return NULL;
443 if (src_reg) {
444 src_buf = src_reg->digest;
445 } else {
446 if (!data_size) {
447 memset(buf, 0, 20);
448 src_buf = buf;
449 } else if (data_size == 1) {
450 memset(buf, *data, 20);
451 src_buf = buf;
452 } else if (data_size >= 20) {
453 src_buf = data;
454 } else {
455 src_buf = buf;
456 for (ptr = (uint8_t *)src_buf, i = 20; i > 0;
457 i -= data_size, ptr += data_size)
458 memcpy(ptr, data,
459 min_t(size_t, i, data_size));
460 }
461 }
462 bin_func(dst_reg->digest, src_buf, 20);
463 dst_reg->valid = true;
464 dst_modified = true;
465 break;
466 case HRE_LOADKEY:
467 if (hre_op_loadkey(tpm, src_reg, dst_reg, data, data_size))
468 return NULL;
469 break;
470 default:
471 return NULL;
472 }
473
474 if (dst_reg && dst_modified && IS_PCR_HREG(dst_spec)) {
475 hre_tpm_err = tpm_extend(tpm, HREG_IDX(dst_spec),
476 dst_reg->digest, dst_reg->digest);
477 if (hre_tpm_err) {
478 hre_err = HRE_E_TPM_FAILURE;
479 return NULL;
480 }
481 }
482 end:
483 *ip += 4;
484 *code_size -= 4;
485 if (opcode & 0x80) {
486 *ip += data_size;
487 *code_size -= data_size;
488 }
489
490 return *ip;
491 }
492
493 /**
494 * @brief runs a program on the hash register engine.
495 * @param tpm TPM device
496 * @param code pointer to the (HRE) code.
497 * @param code_size size of the code (in bytes).
498 * @return 0 on success, != 0 on failure.
499 */
hre_run_program(struct udevice * tpm,const uint8_t * code,size_t code_size)500 int hre_run_program(struct udevice *tpm, const uint8_t *code, size_t code_size)
501 {
502 size_t code_left;
503 const uint8_t *ip = code;
504
505 code_left = code_size;
506 hre_tpm_err = 0;
507 hre_err = HRE_E_OK;
508 while (code_left > 0)
509 if (!hre_execute_op(tpm, &ip, &code_left))
510 return -1;
511
512 return hre_err;
513 }
514
hre_verify_program(struct key_program * prg)515 int hre_verify_program(struct key_program *prg)
516 {
517 uint32_t crc;
518
519 crc = crc32(0, prg->code, prg->code_size);
520
521 if (crc != prg->code_crc) {
522 printf("HRC crc mismatch: %08x != %08x\n",
523 crc, prg->code_crc);
524 return 1;
525 }
526 return 0;
527 }
528