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1 /** @file
2 Implement authentication services for the authenticated variables.
3
4 Caution: This module requires additional review when modified.
5 This driver will have external input - variable data. It may be input in SMM mode.
6 This external input must be validated carefully to avoid security issue like
7 buffer overflow, integer overflow.
8 Variable attribute should also be checked to avoid authentication bypass.
9 The whole SMM authentication variable design relies on the integrity of flash part and SMM.
10 which is assumed to be protected by platform. All variable code and metadata in flash/SMM Memory
11 may not be modified without authorization. If platform fails to protect these resources,
12 the authentication service provided in this driver will be broken, and the behavior is undefined.
13
14 ProcessVarWithPk(), ProcessVarWithKek() and ProcessVariable() are the function to do
15 variable authentication.
16
17 VerifyTimeBasedPayloadAndUpdate() and VerifyCounterBasedPayload() are sub function to do verification.
18 They will do basic validation for authentication data structure, then call crypto library
19 to verify the signature.
20
21 Copyright (c) 2009 - 2019, Intel Corporation. All rights reserved.<BR>
22 Copyright (c) Microsoft Corporation.
23 SPDX-License-Identifier: BSD-2-Clause-Patent
24
25 **/
26
27 #include "AuthServiceInternal.h"
28
29 #include <Protocol/VariablePolicy.h>
30 #include <Library/VariablePolicyLib.h>
31
32 //
33 // Public Exponent of RSA Key.
34 //
35 CONST UINT8 mRsaE[] = { 0x01, 0x00, 0x01 };
36
37 CONST UINT8 mSha256OidValue[] = { 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01 };
38
39 //
40 // Requirement for different signature type which have been defined in UEFI spec.
41 // These data are used to perform SignatureList format check while setting PK/KEK variable.
42 //
43 EFI_SIGNATURE_ITEM mSupportSigItem[] = {
44 //{SigType, SigHeaderSize, SigDataSize }
45 {EFI_CERT_SHA256_GUID, 0, 32 },
46 {EFI_CERT_RSA2048_GUID, 0, 256 },
47 {EFI_CERT_RSA2048_SHA256_GUID, 0, 256 },
48 {EFI_CERT_SHA1_GUID, 0, 20 },
49 {EFI_CERT_RSA2048_SHA1_GUID, 0, 256 },
50 {EFI_CERT_X509_GUID, 0, ((UINT32) ~0)},
51 {EFI_CERT_SHA224_GUID, 0, 28 },
52 {EFI_CERT_SHA384_GUID, 0, 48 },
53 {EFI_CERT_SHA512_GUID, 0, 64 },
54 {EFI_CERT_X509_SHA256_GUID, 0, 48 },
55 {EFI_CERT_X509_SHA384_GUID, 0, 64 },
56 {EFI_CERT_X509_SHA512_GUID, 0, 80 }
57 };
58
59 /**
60 Finds variable in storage blocks of volatile and non-volatile storage areas.
61
62 This code finds variable in storage blocks of volatile and non-volatile storage areas.
63 If VariableName is an empty string, then we just return the first
64 qualified variable without comparing VariableName and VendorGuid.
65
66 @param[in] VariableName Name of the variable to be found.
67 @param[in] VendorGuid Variable vendor GUID to be found.
68 @param[out] Data Pointer to data address.
69 @param[out] DataSize Pointer to data size.
70
71 @retval EFI_INVALID_PARAMETER If VariableName is not an empty string,
72 while VendorGuid is NULL.
73 @retval EFI_SUCCESS Variable successfully found.
74 @retval EFI_NOT_FOUND Variable not found
75
76 **/
77 EFI_STATUS
78 AuthServiceInternalFindVariable (
79 IN CHAR16 *VariableName,
80 IN EFI_GUID *VendorGuid,
81 OUT VOID **Data,
82 OUT UINTN *DataSize
83 )
84 {
85 EFI_STATUS Status;
86 AUTH_VARIABLE_INFO AuthVariableInfo;
87
88 ZeroMem (&AuthVariableInfo, sizeof (AuthVariableInfo));
89 Status = mAuthVarLibContextIn->FindVariable (
90 VariableName,
91 VendorGuid,
92 &AuthVariableInfo
93 );
94 *Data = AuthVariableInfo.Data;
95 *DataSize = AuthVariableInfo.DataSize;
96 return Status;
97 }
98
99 /**
100 Update the variable region with Variable information.
101
102 @param[in] VariableName Name of variable.
103 @param[in] VendorGuid Guid of variable.
104 @param[in] Data Data pointer.
105 @param[in] DataSize Size of Data.
106 @param[in] Attributes Attribute value of the variable.
107
108 @retval EFI_SUCCESS The update operation is success.
109 @retval EFI_INVALID_PARAMETER Invalid parameter.
110 @retval EFI_WRITE_PROTECTED Variable is write-protected.
111 @retval EFI_OUT_OF_RESOURCES There is not enough resource.
112
113 **/
114 EFI_STATUS
115 AuthServiceInternalUpdateVariable (
116 IN CHAR16 *VariableName,
117 IN EFI_GUID *VendorGuid,
118 IN VOID *Data,
119 IN UINTN DataSize,
120 IN UINT32 Attributes
121 )
122 {
123 AUTH_VARIABLE_INFO AuthVariableInfo;
124
125 ZeroMem (&AuthVariableInfo, sizeof (AuthVariableInfo));
126 AuthVariableInfo.VariableName = VariableName;
127 AuthVariableInfo.VendorGuid = VendorGuid;
128 AuthVariableInfo.Data = Data;
129 AuthVariableInfo.DataSize = DataSize;
130 AuthVariableInfo.Attributes = Attributes;
131
132 return mAuthVarLibContextIn->UpdateVariable (
133 &AuthVariableInfo
134 );
135 }
136
137 /**
138 Update the variable region with Variable information.
139
140 @param[in] VariableName Name of variable.
141 @param[in] VendorGuid Guid of variable.
142 @param[in] Data Data pointer.
143 @param[in] DataSize Size of Data.
144 @param[in] Attributes Attribute value of the variable.
145 @param[in] TimeStamp Value of associated TimeStamp.
146
147 @retval EFI_SUCCESS The update operation is success.
148 @retval EFI_INVALID_PARAMETER Invalid parameter.
149 @retval EFI_WRITE_PROTECTED Variable is write-protected.
150 @retval EFI_OUT_OF_RESOURCES There is not enough resource.
151
152 **/
153 EFI_STATUS
154 AuthServiceInternalUpdateVariableWithTimeStamp (
155 IN CHAR16 *VariableName,
156 IN EFI_GUID *VendorGuid,
157 IN VOID *Data,
158 IN UINTN DataSize,
159 IN UINT32 Attributes,
160 IN EFI_TIME *TimeStamp
161 )
162 {
163 EFI_STATUS FindStatus;
164 VOID *OrgData;
165 UINTN OrgDataSize;
166 AUTH_VARIABLE_INFO AuthVariableInfo;
167
168 FindStatus = AuthServiceInternalFindVariable (
169 VariableName,
170 VendorGuid,
171 &OrgData,
172 &OrgDataSize
173 );
174
175 //
176 // EFI_VARIABLE_APPEND_WRITE attribute only effects for existing variable
177 //
178 if (!EFI_ERROR (FindStatus) && ((Attributes & EFI_VARIABLE_APPEND_WRITE) != 0)) {
179 if ((CompareGuid (VendorGuid, &gEfiImageSecurityDatabaseGuid) &&
180 ((StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE) == 0) || (StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE1) == 0) ||
181 (StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE2) == 0))) ||
182 (CompareGuid (VendorGuid, &gEfiGlobalVariableGuid) && (StrCmp (VariableName, EFI_KEY_EXCHANGE_KEY_NAME) == 0))) {
183 //
184 // For variables with formatted as EFI_SIGNATURE_LIST, the driver shall not perform an append of
185 // EFI_SIGNATURE_DATA values that are already part of the existing variable value.
186 //
187 FilterSignatureList (
188 OrgData,
189 OrgDataSize,
190 Data,
191 &DataSize
192 );
193 }
194 }
195
196 ZeroMem (&AuthVariableInfo, sizeof (AuthVariableInfo));
197 AuthVariableInfo.VariableName = VariableName;
198 AuthVariableInfo.VendorGuid = VendorGuid;
199 AuthVariableInfo.Data = Data;
200 AuthVariableInfo.DataSize = DataSize;
201 AuthVariableInfo.Attributes = Attributes;
202 AuthVariableInfo.TimeStamp = TimeStamp;
203 return mAuthVarLibContextIn->UpdateVariable (
204 &AuthVariableInfo
205 );
206 }
207
208 /**
209 Determine whether this operation needs a physical present user.
210
211 @param[in] VariableName Name of the Variable.
212 @param[in] VendorGuid GUID of the Variable.
213
214 @retval TRUE This variable is protected, only a physical present user could set this variable.
215 @retval FALSE This variable is not protected.
216
217 **/
218 BOOLEAN
219 NeedPhysicallyPresent(
220 IN CHAR16 *VariableName,
221 IN EFI_GUID *VendorGuid
222 )
223 {
224 // If the VariablePolicy engine is disabled, allow deletion of any authenticated variables.
225 if (IsVariablePolicyEnabled()) {
226 if ((CompareGuid (VendorGuid, &gEfiSecureBootEnableDisableGuid) && (StrCmp (VariableName, EFI_SECURE_BOOT_ENABLE_NAME) == 0))
227 || (CompareGuid (VendorGuid, &gEfiCustomModeEnableGuid) && (StrCmp (VariableName, EFI_CUSTOM_MODE_NAME) == 0))) {
228 return TRUE;
229 }
230 }
231
232 return FALSE;
233 }
234
235 /**
236 Determine whether the platform is operating in Custom Secure Boot mode.
237
238 @retval TRUE The platform is operating in Custom mode.
239 @retval FALSE The platform is operating in Standard mode.
240
241 **/
242 BOOLEAN
243 InCustomMode (
244 VOID
245 )
246 {
247 EFI_STATUS Status;
248 VOID *Data;
249 UINTN DataSize;
250
251 Status = AuthServiceInternalFindVariable (EFI_CUSTOM_MODE_NAME, &gEfiCustomModeEnableGuid, &Data, &DataSize);
252 if (!EFI_ERROR (Status) && (*(UINT8 *) Data == CUSTOM_SECURE_BOOT_MODE)) {
253 return TRUE;
254 }
255
256 return FALSE;
257 }
258
259 /**
260 Update platform mode.
261
262 @param[in] Mode SETUP_MODE or USER_MODE.
263
264 @return EFI_INVALID_PARAMETER Invalid parameter.
265 @return EFI_SUCCESS Update platform mode successfully.
266
267 **/
268 EFI_STATUS
269 UpdatePlatformMode (
270 IN UINT32 Mode
271 )
272 {
273 EFI_STATUS Status;
274 VOID *Data;
275 UINTN DataSize;
276 UINT8 SecureBootMode;
277 UINT8 SecureBootEnable;
278 UINTN VariableDataSize;
279
280 Status = AuthServiceInternalFindVariable (
281 EFI_SETUP_MODE_NAME,
282 &gEfiGlobalVariableGuid,
283 &Data,
284 &DataSize
285 );
286 if (EFI_ERROR (Status)) {
287 return Status;
288 }
289
290 //
291 // Update the value of SetupMode variable by a simple mem copy, this could avoid possible
292 // variable storage reclaim at runtime.
293 //
294 mPlatformMode = (UINT8) Mode;
295 CopyMem (Data, &mPlatformMode, sizeof(UINT8));
296
297 if (mAuthVarLibContextIn->AtRuntime ()) {
298 //
299 // SecureBoot Variable indicates whether the platform firmware is operating
300 // in Secure boot mode (1) or not (0), so we should not change SecureBoot
301 // Variable in runtime.
302 //
303 return Status;
304 }
305
306 //
307 // Check "SecureBoot" variable's existence.
308 // If it doesn't exist, firmware has no capability to perform driver signing verification,
309 // then set "SecureBoot" to 0.
310 //
311 Status = AuthServiceInternalFindVariable (
312 EFI_SECURE_BOOT_MODE_NAME,
313 &gEfiGlobalVariableGuid,
314 &Data,
315 &DataSize
316 );
317 //
318 // If "SecureBoot" variable exists, then check "SetupMode" variable update.
319 // If "SetupMode" variable is USER_MODE, "SecureBoot" variable is set to 1.
320 // If "SetupMode" variable is SETUP_MODE, "SecureBoot" variable is set to 0.
321 //
322 if (EFI_ERROR (Status)) {
323 SecureBootMode = SECURE_BOOT_MODE_DISABLE;
324 } else {
325 if (mPlatformMode == USER_MODE) {
326 SecureBootMode = SECURE_BOOT_MODE_ENABLE;
327 } else if (mPlatformMode == SETUP_MODE) {
328 SecureBootMode = SECURE_BOOT_MODE_DISABLE;
329 } else {
330 return EFI_NOT_FOUND;
331 }
332 }
333
334 Status = AuthServiceInternalUpdateVariable (
335 EFI_SECURE_BOOT_MODE_NAME,
336 &gEfiGlobalVariableGuid,
337 &SecureBootMode,
338 sizeof(UINT8),
339 EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS
340 );
341 if (EFI_ERROR (Status)) {
342 return Status;
343 }
344
345 //
346 // Check "SecureBootEnable" variable's existence. It can enable/disable secure boot feature.
347 //
348 Status = AuthServiceInternalFindVariable (
349 EFI_SECURE_BOOT_ENABLE_NAME,
350 &gEfiSecureBootEnableDisableGuid,
351 &Data,
352 &DataSize
353 );
354
355 if (SecureBootMode == SECURE_BOOT_MODE_ENABLE) {
356 //
357 // Create the "SecureBootEnable" variable as secure boot is enabled.
358 //
359 SecureBootEnable = SECURE_BOOT_ENABLE;
360 VariableDataSize = sizeof (SecureBootEnable);
361 } else {
362 //
363 // Delete the "SecureBootEnable" variable if this variable exist as "SecureBoot"
364 // variable is not in secure boot state.
365 //
366 if (EFI_ERROR (Status)) {
367 return EFI_SUCCESS;
368 }
369 SecureBootEnable = SECURE_BOOT_DISABLE;
370 VariableDataSize = 0;
371 }
372
373 Status = AuthServiceInternalUpdateVariable (
374 EFI_SECURE_BOOT_ENABLE_NAME,
375 &gEfiSecureBootEnableDisableGuid,
376 &SecureBootEnable,
377 VariableDataSize,
378 EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS
379 );
380 return Status;
381 }
382
383 /**
384 Check input data form to make sure it is a valid EFI_SIGNATURE_LIST for PK/KEK/db/dbx/dbt variable.
385
386 @param[in] VariableName Name of Variable to be check.
387 @param[in] VendorGuid Variable vendor GUID.
388 @param[in] Data Point to the variable data to be checked.
389 @param[in] DataSize Size of Data.
390
391 @return EFI_INVALID_PARAMETER Invalid signature list format.
392 @return EFI_SUCCESS Passed signature list format check successfully.
393
394 **/
395 EFI_STATUS
396 CheckSignatureListFormat(
397 IN CHAR16 *VariableName,
398 IN EFI_GUID *VendorGuid,
399 IN VOID *Data,
400 IN UINTN DataSize
401 )
402 {
403 EFI_SIGNATURE_LIST *SigList;
404 UINTN SigDataSize;
405 UINT32 Index;
406 UINT32 SigCount;
407 BOOLEAN IsPk;
408 VOID *RsaContext;
409 EFI_SIGNATURE_DATA *CertData;
410 UINTN CertLen;
411
412 if (DataSize == 0) {
413 return EFI_SUCCESS;
414 }
415
416 ASSERT (VariableName != NULL && VendorGuid != NULL && Data != NULL);
417
418 if (CompareGuid (VendorGuid, &gEfiGlobalVariableGuid) && (StrCmp (VariableName, EFI_PLATFORM_KEY_NAME) == 0)){
419 IsPk = TRUE;
420 } else if ((CompareGuid (VendorGuid, &gEfiGlobalVariableGuid) && (StrCmp (VariableName, EFI_KEY_EXCHANGE_KEY_NAME) == 0)) ||
421 (CompareGuid (VendorGuid, &gEfiImageSecurityDatabaseGuid) &&
422 ((StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE) == 0) || (StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE1) == 0) ||
423 (StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE2) == 0)))) {
424 IsPk = FALSE;
425 } else {
426 return EFI_SUCCESS;
427 }
428
429 SigCount = 0;
430 SigList = (EFI_SIGNATURE_LIST *) Data;
431 SigDataSize = DataSize;
432 RsaContext = NULL;
433
434 //
435 // Walk through the input signature list and check the data format.
436 // If any signature is incorrectly formed, the whole check will fail.
437 //
438 while ((SigDataSize > 0) && (SigDataSize >= SigList->SignatureListSize)) {
439 for (Index = 0; Index < (sizeof (mSupportSigItem) / sizeof (EFI_SIGNATURE_ITEM)); Index++ ) {
440 if (CompareGuid (&SigList->SignatureType, &mSupportSigItem[Index].SigType)) {
441 //
442 // The value of SignatureSize should always be 16 (size of SignatureOwner
443 // component) add the data length according to signature type.
444 //
445 if (mSupportSigItem[Index].SigDataSize != ((UINT32) ~0) &&
446 (SigList->SignatureSize - sizeof (EFI_GUID)) != mSupportSigItem[Index].SigDataSize) {
447 return EFI_INVALID_PARAMETER;
448 }
449 if (mSupportSigItem[Index].SigHeaderSize != ((UINT32) ~0) &&
450 SigList->SignatureHeaderSize != mSupportSigItem[Index].SigHeaderSize) {
451 return EFI_INVALID_PARAMETER;
452 }
453 break;
454 }
455 }
456
457 if (Index == (sizeof (mSupportSigItem) / sizeof (EFI_SIGNATURE_ITEM))) {
458 //
459 // Undefined signature type.
460 //
461 return EFI_INVALID_PARAMETER;
462 }
463
464 if (CompareGuid (&SigList->SignatureType, &gEfiCertX509Guid)) {
465 //
466 // Try to retrieve the RSA public key from the X.509 certificate.
467 // If this operation fails, it's not a valid certificate.
468 //
469 RsaContext = RsaNew ();
470 if (RsaContext == NULL) {
471 return EFI_INVALID_PARAMETER;
472 }
473 CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) SigList + sizeof (EFI_SIGNATURE_LIST) + SigList->SignatureHeaderSize);
474 CertLen = SigList->SignatureSize - sizeof (EFI_GUID);
475 if (!RsaGetPublicKeyFromX509 (CertData->SignatureData, CertLen, &RsaContext)) {
476 RsaFree (RsaContext);
477 return EFI_INVALID_PARAMETER;
478 }
479 RsaFree (RsaContext);
480 }
481
482 if ((SigList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - SigList->SignatureHeaderSize) % SigList->SignatureSize != 0) {
483 return EFI_INVALID_PARAMETER;
484 }
485 SigCount += (SigList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - SigList->SignatureHeaderSize) / SigList->SignatureSize;
486
487 SigDataSize -= SigList->SignatureListSize;
488 SigList = (EFI_SIGNATURE_LIST *) ((UINT8 *) SigList + SigList->SignatureListSize);
489 }
490
491 if (((UINTN) SigList - (UINTN) Data) != DataSize) {
492 return EFI_INVALID_PARAMETER;
493 }
494
495 if (IsPk && SigCount > 1) {
496 return EFI_INVALID_PARAMETER;
497 }
498
499 return EFI_SUCCESS;
500 }
501
502 /**
503 Update "VendorKeys" variable to record the out of band secure boot key modification.
504
505 @return EFI_SUCCESS Variable is updated successfully.
506 @return Others Failed to update variable.
507
508 **/
509 EFI_STATUS
510 VendorKeyIsModified (
511 VOID
512 )
513 {
514 EFI_STATUS Status;
515
516 if (mVendorKeyState == VENDOR_KEYS_MODIFIED) {
517 return EFI_SUCCESS;
518 }
519 mVendorKeyState = VENDOR_KEYS_MODIFIED;
520
521 Status = AuthServiceInternalUpdateVariable (
522 EFI_VENDOR_KEYS_NV_VARIABLE_NAME,
523 &gEfiVendorKeysNvGuid,
524 &mVendorKeyState,
525 sizeof (UINT8),
526 EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS
527 );
528 if (EFI_ERROR (Status)) {
529 return Status;
530 }
531
532 return AuthServiceInternalUpdateVariable (
533 EFI_VENDOR_KEYS_VARIABLE_NAME,
534 &gEfiGlobalVariableGuid,
535 &mVendorKeyState,
536 sizeof (UINT8),
537 EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS
538 );
539 }
540
541 /**
542 Process variable with platform key for verification.
543
544 Caution: This function may receive untrusted input.
545 This function may be invoked in SMM mode, and datasize and data are external input.
546 This function will do basic validation, before parse the data.
547 This function will parse the authentication carefully to avoid security issues, like
548 buffer overflow, integer overflow.
549 This function will check attribute carefully to avoid authentication bypass.
550
551 @param[in] VariableName Name of Variable to be found.
552 @param[in] VendorGuid Variable vendor GUID.
553 @param[in] Data Data pointer.
554 @param[in] DataSize Size of Data found. If size is less than the
555 data, this value contains the required size.
556 @param[in] Attributes Attribute value of the variable
557 @param[in] IsPk Indicate whether it is to process pk.
558
559 @return EFI_INVALID_PARAMETER Invalid parameter.
560 @return EFI_SECURITY_VIOLATION The variable does NOT pass the validation.
561 check carried out by the firmware.
562 @return EFI_SUCCESS Variable passed validation successfully.
563
564 **/
565 EFI_STATUS
566 ProcessVarWithPk (
567 IN CHAR16 *VariableName,
568 IN EFI_GUID *VendorGuid,
569 IN VOID *Data,
570 IN UINTN DataSize,
571 IN UINT32 Attributes OPTIONAL,
572 IN BOOLEAN IsPk
573 )
574 {
575 EFI_STATUS Status;
576 BOOLEAN Del;
577 UINT8 *Payload;
578 UINTN PayloadSize;
579
580 if ((Attributes & EFI_VARIABLE_NON_VOLATILE) == 0 ||
581 (Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) == 0) {
582 //
583 // PK, KEK and db/dbx/dbt should set EFI_VARIABLE_NON_VOLATILE attribute and should be a time-based
584 // authenticated variable.
585 //
586 return EFI_INVALID_PARAMETER;
587 }
588
589 //
590 // Init state of Del. State may change due to secure check
591 //
592 Del = FALSE;
593 if ((InCustomMode() && UserPhysicalPresent()) || (mPlatformMode == SETUP_MODE && !IsPk)) {
594 Payload = (UINT8 *) Data + AUTHINFO2_SIZE (Data);
595 PayloadSize = DataSize - AUTHINFO2_SIZE (Data);
596 if (PayloadSize == 0) {
597 Del = TRUE;
598 }
599
600 Status = CheckSignatureListFormat(VariableName, VendorGuid, Payload, PayloadSize);
601 if (EFI_ERROR (Status)) {
602 return Status;
603 }
604
605 Status = AuthServiceInternalUpdateVariableWithTimeStamp (
606 VariableName,
607 VendorGuid,
608 Payload,
609 PayloadSize,
610 Attributes,
611 &((EFI_VARIABLE_AUTHENTICATION_2 *) Data)->TimeStamp
612 );
613 if (EFI_ERROR(Status)) {
614 return Status;
615 }
616
617 if ((mPlatformMode != SETUP_MODE) || IsPk) {
618 Status = VendorKeyIsModified ();
619 }
620 } else if (mPlatformMode == USER_MODE) {
621 //
622 // Verify against X509 Cert in PK database.
623 //
624 Status = VerifyTimeBasedPayloadAndUpdate (
625 VariableName,
626 VendorGuid,
627 Data,
628 DataSize,
629 Attributes,
630 AuthVarTypePk,
631 &Del
632 );
633 } else {
634 //
635 // Verify against the certificate in data payload.
636 //
637 Status = VerifyTimeBasedPayloadAndUpdate (
638 VariableName,
639 VendorGuid,
640 Data,
641 DataSize,
642 Attributes,
643 AuthVarTypePayload,
644 &Del
645 );
646 }
647
648 if (!EFI_ERROR(Status) && IsPk) {
649 if (mPlatformMode == SETUP_MODE && !Del) {
650 //
651 // If enroll PK in setup mode, need change to user mode.
652 //
653 Status = UpdatePlatformMode (USER_MODE);
654 } else if (mPlatformMode == USER_MODE && Del){
655 //
656 // If delete PK in user mode, need change to setup mode.
657 //
658 Status = UpdatePlatformMode (SETUP_MODE);
659 }
660 }
661
662 return Status;
663 }
664
665 /**
666 Process variable with key exchange key for verification.
667
668 Caution: This function may receive untrusted input.
669 This function may be invoked in SMM mode, and datasize and data are external input.
670 This function will do basic validation, before parse the data.
671 This function will parse the authentication carefully to avoid security issues, like
672 buffer overflow, integer overflow.
673 This function will check attribute carefully to avoid authentication bypass.
674
675 @param[in] VariableName Name of Variable to be found.
676 @param[in] VendorGuid Variable vendor GUID.
677 @param[in] Data Data pointer.
678 @param[in] DataSize Size of Data found. If size is less than the
679 data, this value contains the required size.
680 @param[in] Attributes Attribute value of the variable.
681
682 @return EFI_INVALID_PARAMETER Invalid parameter.
683 @return EFI_SECURITY_VIOLATION The variable does NOT pass the validation
684 check carried out by the firmware.
685 @return EFI_SUCCESS Variable pass validation successfully.
686
687 **/
688 EFI_STATUS
689 ProcessVarWithKek (
690 IN CHAR16 *VariableName,
691 IN EFI_GUID *VendorGuid,
692 IN VOID *Data,
693 IN UINTN DataSize,
694 IN UINT32 Attributes OPTIONAL
695 )
696 {
697 EFI_STATUS Status;
698 UINT8 *Payload;
699 UINTN PayloadSize;
700
701 if ((Attributes & EFI_VARIABLE_NON_VOLATILE) == 0 ||
702 (Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) == 0) {
703 //
704 // DB, DBX and DBT should set EFI_VARIABLE_NON_VOLATILE attribute and should be a time-based
705 // authenticated variable.
706 //
707 return EFI_INVALID_PARAMETER;
708 }
709
710 Status = EFI_SUCCESS;
711 if (mPlatformMode == USER_MODE && !(InCustomMode() && UserPhysicalPresent())) {
712 //
713 // Time-based, verify against X509 Cert KEK.
714 //
715 return VerifyTimeBasedPayloadAndUpdate (
716 VariableName,
717 VendorGuid,
718 Data,
719 DataSize,
720 Attributes,
721 AuthVarTypeKek,
722 NULL
723 );
724 } else {
725 //
726 // If in setup mode or custom secure boot mode, no authentication needed.
727 //
728 Payload = (UINT8 *) Data + AUTHINFO2_SIZE (Data);
729 PayloadSize = DataSize - AUTHINFO2_SIZE (Data);
730
731 Status = CheckSignatureListFormat(VariableName, VendorGuid, Payload, PayloadSize);
732 if (EFI_ERROR (Status)) {
733 return Status;
734 }
735
736 Status = AuthServiceInternalUpdateVariableWithTimeStamp (
737 VariableName,
738 VendorGuid,
739 Payload,
740 PayloadSize,
741 Attributes,
742 &((EFI_VARIABLE_AUTHENTICATION_2 *) Data)->TimeStamp
743 );
744 if (EFI_ERROR (Status)) {
745 return Status;
746 }
747
748 if (mPlatformMode != SETUP_MODE) {
749 Status = VendorKeyIsModified ();
750 }
751 }
752
753 return Status;
754 }
755
756 /**
757 Check if it is to delete auth variable.
758
759 @param[in] OrgAttributes Original attribute value of the variable.
760 @param[in] Data Data pointer.
761 @param[in] DataSize Size of Data.
762 @param[in] Attributes Attribute value of the variable.
763
764 @retval TRUE It is to delete auth variable.
765 @retval FALSE It is not to delete auth variable.
766
767 **/
768 BOOLEAN
769 IsDeleteAuthVariable (
770 IN UINT32 OrgAttributes,
771 IN VOID *Data,
772 IN UINTN DataSize,
773 IN UINT32 Attributes
774 )
775 {
776 BOOLEAN Del;
777 UINTN PayloadSize;
778
779 Del = FALSE;
780
781 //
782 // To delete a variable created with the EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS
783 // or the EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS attribute,
784 // SetVariable must be used with attributes matching the existing variable
785 // and the DataSize set to the size of the AuthInfo descriptor.
786 //
787 if ((Attributes == OrgAttributes) &&
788 ((Attributes & (EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)) != 0)) {
789 if ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) {
790 PayloadSize = DataSize - AUTHINFO2_SIZE (Data);
791 if (PayloadSize == 0) {
792 Del = TRUE;
793 }
794 } else {
795 PayloadSize = DataSize - AUTHINFO_SIZE;
796 if (PayloadSize == 0) {
797 Del = TRUE;
798 }
799 }
800 }
801
802 return Del;
803 }
804
805 /**
806 Process variable with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set
807
808 Caution: This function may receive untrusted input.
809 This function may be invoked in SMM mode, and datasize and data are external input.
810 This function will do basic validation, before parse the data.
811 This function will parse the authentication carefully to avoid security issues, like
812 buffer overflow, integer overflow.
813 This function will check attribute carefully to avoid authentication bypass.
814
815 @param[in] VariableName Name of the variable.
816 @param[in] VendorGuid Variable vendor GUID.
817 @param[in] Data Data pointer.
818 @param[in] DataSize Size of Data.
819 @param[in] Attributes Attribute value of the variable.
820
821 @return EFI_INVALID_PARAMETER Invalid parameter.
822 @return EFI_WRITE_PROTECTED Variable is write-protected and needs authentication with
823 EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS or EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set.
824 @return EFI_OUT_OF_RESOURCES The Database to save the public key is full.
825 @return EFI_SECURITY_VIOLATION The variable is with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS
826 set, but the AuthInfo does NOT pass the validation
827 check carried out by the firmware.
828 @return EFI_SUCCESS Variable is not write-protected or pass validation successfully.
829
830 **/
831 EFI_STATUS
832 ProcessVariable (
833 IN CHAR16 *VariableName,
834 IN EFI_GUID *VendorGuid,
835 IN VOID *Data,
836 IN UINTN DataSize,
837 IN UINT32 Attributes
838 )
839 {
840 EFI_STATUS Status;
841 AUTH_VARIABLE_INFO OrgVariableInfo;
842
843 Status = EFI_SUCCESS;
844
845 ZeroMem (&OrgVariableInfo, sizeof (OrgVariableInfo));
846 Status = mAuthVarLibContextIn->FindVariable (
847 VariableName,
848 VendorGuid,
849 &OrgVariableInfo
850 );
851
852 // If the VariablePolicy engine is disabled, allow deletion of any authenticated variables.
853 if ((!EFI_ERROR (Status)) && IsDeleteAuthVariable (OrgVariableInfo.Attributes, Data, DataSize, Attributes) && (UserPhysicalPresent() || !IsVariablePolicyEnabled())) {
854 //
855 // Allow the delete operation of common authenticated variable(AT or AW) at user physical presence.
856 //
857 Status = AuthServiceInternalUpdateVariable (
858 VariableName,
859 VendorGuid,
860 NULL,
861 0,
862 0
863 );
864 if (!EFI_ERROR (Status) && ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0)) {
865 Status = DeleteCertsFromDb (VariableName, VendorGuid, Attributes);
866 }
867
868 return Status;
869 }
870
871 if (NeedPhysicallyPresent (VariableName, VendorGuid) && !UserPhysicalPresent()) {
872 //
873 // This variable is protected, only physical present user could modify its value.
874 //
875 return EFI_SECURITY_VIOLATION;
876 }
877
878 //
879 if ((Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) != 0) {
880 //
881 // Reject Counter Based Auth Variable processing request.
882 //
883 return EFI_UNSUPPORTED;
884 } else if ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) {
885 //
886 // Process Time-based Authenticated variable.
887 //
888 return VerifyTimeBasedPayloadAndUpdate (
889 VariableName,
890 VendorGuid,
891 Data,
892 DataSize,
893 Attributes,
894 AuthVarTypePriv,
895 NULL
896 );
897 }
898
899 if ((OrgVariableInfo.Data != NULL) &&
900 ((OrgVariableInfo.Attributes & (EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)) != 0)) {
901 //
902 // If the variable is already write-protected, it always needs authentication before update.
903 //
904 return EFI_WRITE_PROTECTED;
905 }
906
907 //
908 // Not authenticated variable, just update variable as usual.
909 //
910 Status = AuthServiceInternalUpdateVariable (VariableName, VendorGuid, Data, DataSize, Attributes);
911 return Status;
912
913 }
914
915 /**
916 Filter out the duplicated EFI_SIGNATURE_DATA from the new data by comparing to the original data.
917
918 @param[in] Data Pointer to original EFI_SIGNATURE_LIST.
919 @param[in] DataSize Size of Data buffer.
920 @param[in, out] NewData Pointer to new EFI_SIGNATURE_LIST.
921 @param[in, out] NewDataSize Size of NewData buffer.
922
923 **/
924 EFI_STATUS
925 FilterSignatureList (
926 IN VOID *Data,
927 IN UINTN DataSize,
928 IN OUT VOID *NewData,
929 IN OUT UINTN *NewDataSize
930 )
931 {
932 EFI_SIGNATURE_LIST *CertList;
933 EFI_SIGNATURE_DATA *Cert;
934 UINTN CertCount;
935 EFI_SIGNATURE_LIST *NewCertList;
936 EFI_SIGNATURE_DATA *NewCert;
937 UINTN NewCertCount;
938 UINTN Index;
939 UINTN Index2;
940 UINTN Size;
941 UINT8 *Tail;
942 UINTN CopiedCount;
943 UINTN SignatureListSize;
944 BOOLEAN IsNewCert;
945 UINT8 *TempData;
946 UINTN TempDataSize;
947 EFI_STATUS Status;
948
949 if (*NewDataSize == 0) {
950 return EFI_SUCCESS;
951 }
952
953 TempDataSize = *NewDataSize;
954 Status = mAuthVarLibContextIn->GetScratchBuffer (&TempDataSize, (VOID **) &TempData);
955 if (EFI_ERROR (Status)) {
956 return EFI_OUT_OF_RESOURCES;
957 }
958
959 Tail = TempData;
960
961 NewCertList = (EFI_SIGNATURE_LIST *) NewData;
962 while ((*NewDataSize > 0) && (*NewDataSize >= NewCertList->SignatureListSize)) {
963 NewCert = (EFI_SIGNATURE_DATA *) ((UINT8 *) NewCertList + sizeof (EFI_SIGNATURE_LIST) + NewCertList->SignatureHeaderSize);
964 NewCertCount = (NewCertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - NewCertList->SignatureHeaderSize) / NewCertList->SignatureSize;
965
966 CopiedCount = 0;
967 for (Index = 0; Index < NewCertCount; Index++) {
968 IsNewCert = TRUE;
969
970 Size = DataSize;
971 CertList = (EFI_SIGNATURE_LIST *) Data;
972 while ((Size > 0) && (Size >= CertList->SignatureListSize)) {
973 if (CompareGuid (&CertList->SignatureType, &NewCertList->SignatureType) &&
974 (CertList->SignatureSize == NewCertList->SignatureSize)) {
975 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
976 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
977 for (Index2 = 0; Index2 < CertCount; Index2++) {
978 //
979 // Iterate each Signature Data in this Signature List.
980 //
981 if (CompareMem (NewCert, Cert, CertList->SignatureSize) == 0) {
982 IsNewCert = FALSE;
983 break;
984 }
985 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);
986 }
987 }
988
989 if (!IsNewCert) {
990 break;
991 }
992 Size -= CertList->SignatureListSize;
993 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
994 }
995
996 if (IsNewCert) {
997 //
998 // New EFI_SIGNATURE_DATA, keep it.
999 //
1000 if (CopiedCount == 0) {
1001 //
1002 // Copy EFI_SIGNATURE_LIST header for only once.
1003 //
1004 CopyMem (Tail, NewCertList, sizeof (EFI_SIGNATURE_LIST) + NewCertList->SignatureHeaderSize);
1005 Tail = Tail + sizeof (EFI_SIGNATURE_LIST) + NewCertList->SignatureHeaderSize;
1006 }
1007
1008 CopyMem (Tail, NewCert, NewCertList->SignatureSize);
1009 Tail += NewCertList->SignatureSize;
1010 CopiedCount++;
1011 }
1012
1013 NewCert = (EFI_SIGNATURE_DATA *) ((UINT8 *) NewCert + NewCertList->SignatureSize);
1014 }
1015
1016 //
1017 // Update SignatureListSize in the kept EFI_SIGNATURE_LIST.
1018 //
1019 if (CopiedCount != 0) {
1020 SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + NewCertList->SignatureHeaderSize + (CopiedCount * NewCertList->SignatureSize);
1021 CertList = (EFI_SIGNATURE_LIST *) (Tail - SignatureListSize);
1022 CertList->SignatureListSize = (UINT32) SignatureListSize;
1023 }
1024
1025 *NewDataSize -= NewCertList->SignatureListSize;
1026 NewCertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) NewCertList + NewCertList->SignatureListSize);
1027 }
1028
1029 TempDataSize = (Tail - (UINT8 *) TempData);
1030
1031 CopyMem (NewData, TempData, TempDataSize);
1032 *NewDataSize = TempDataSize;
1033
1034 return EFI_SUCCESS;
1035 }
1036
1037 /**
1038 Compare two EFI_TIME data.
1039
1040
1041 @param FirstTime A pointer to the first EFI_TIME data.
1042 @param SecondTime A pointer to the second EFI_TIME data.
1043
1044 @retval TRUE The FirstTime is not later than the SecondTime.
1045 @retval FALSE The FirstTime is later than the SecondTime.
1046
1047 **/
1048 BOOLEAN
1049 AuthServiceInternalCompareTimeStamp (
1050 IN EFI_TIME *FirstTime,
1051 IN EFI_TIME *SecondTime
1052 )
1053 {
1054 if (FirstTime->Year != SecondTime->Year) {
1055 return (BOOLEAN) (FirstTime->Year < SecondTime->Year);
1056 } else if (FirstTime->Month != SecondTime->Month) {
1057 return (BOOLEAN) (FirstTime->Month < SecondTime->Month);
1058 } else if (FirstTime->Day != SecondTime->Day) {
1059 return (BOOLEAN) (FirstTime->Day < SecondTime->Day);
1060 } else if (FirstTime->Hour != SecondTime->Hour) {
1061 return (BOOLEAN) (FirstTime->Hour < SecondTime->Hour);
1062 } else if (FirstTime->Minute != SecondTime->Minute) {
1063 return (BOOLEAN) (FirstTime->Minute < SecondTime->Minute);
1064 }
1065
1066 return (BOOLEAN) (FirstTime->Second <= SecondTime->Second);
1067 }
1068
1069 /**
1070 Calculate SHA256 digest of SignerCert CommonName + ToplevelCert tbsCertificate
1071 SignerCert and ToplevelCert are inside the signer certificate chain.
1072
1073 @param[in] SignerCert A pointer to SignerCert data.
1074 @param[in] SignerCertSize Length of SignerCert data.
1075 @param[in] TopLevelCert A pointer to TopLevelCert data.
1076 @param[in] TopLevelCertSize Length of TopLevelCert data.
1077 @param[out] Sha256Digest Sha256 digest calculated.
1078
1079 @return EFI_ABORTED Digest process failed.
1080 @return EFI_SUCCESS SHA256 Digest is successfully calculated.
1081
1082 **/
1083 EFI_STATUS
1084 CalculatePrivAuthVarSignChainSHA256Digest(
1085 IN UINT8 *SignerCert,
1086 IN UINTN SignerCertSize,
1087 IN UINT8 *TopLevelCert,
1088 IN UINTN TopLevelCertSize,
1089 OUT UINT8 *Sha256Digest
1090 )
1091 {
1092 UINT8 *TbsCert;
1093 UINTN TbsCertSize;
1094 CHAR8 CertCommonName[128];
1095 UINTN CertCommonNameSize;
1096 BOOLEAN CryptoStatus;
1097 EFI_STATUS Status;
1098
1099 CertCommonNameSize = sizeof(CertCommonName);
1100
1101 //
1102 // Get SignerCert CommonName
1103 //
1104 Status = X509GetCommonName(SignerCert, SignerCertSize, CertCommonName, &CertCommonNameSize);
1105 if (EFI_ERROR(Status)) {
1106 DEBUG((DEBUG_INFO, "%a Get SignerCert CommonName failed with status %x\n", __FUNCTION__, Status));
1107 return EFI_ABORTED;
1108 }
1109
1110 //
1111 // Get TopLevelCert tbsCertificate
1112 //
1113 if (!X509GetTBSCert(TopLevelCert, TopLevelCertSize, &TbsCert, &TbsCertSize)) {
1114 DEBUG((DEBUG_INFO, "%a Get Top-level Cert tbsCertificate failed!\n", __FUNCTION__));
1115 return EFI_ABORTED;
1116 }
1117
1118 //
1119 // Digest SignerCert CN + TopLevelCert tbsCertificate
1120 //
1121 ZeroMem (Sha256Digest, SHA256_DIGEST_SIZE);
1122 CryptoStatus = Sha256Init (mHashCtx);
1123 if (!CryptoStatus) {
1124 return EFI_ABORTED;
1125 }
1126
1127 //
1128 // '\0' is forced in CertCommonName. No overflow issue
1129 //
1130 CryptoStatus = Sha256Update (
1131 mHashCtx,
1132 CertCommonName,
1133 AsciiStrLen (CertCommonName)
1134 );
1135 if (!CryptoStatus) {
1136 return EFI_ABORTED;
1137 }
1138
1139 CryptoStatus = Sha256Update (mHashCtx, TbsCert, TbsCertSize);
1140 if (!CryptoStatus) {
1141 return EFI_ABORTED;
1142 }
1143
1144 CryptoStatus = Sha256Final (mHashCtx, Sha256Digest);
1145 if (!CryptoStatus) {
1146 return EFI_ABORTED;
1147 }
1148
1149 return EFI_SUCCESS;
1150 }
1151
1152 /**
1153 Find matching signer's certificates for common authenticated variable
1154 by corresponding VariableName and VendorGuid from "certdb" or "certdbv".
1155
1156 The data format of "certdb" or "certdbv":
1157 //
1158 // UINT32 CertDbListSize;
1159 // /// AUTH_CERT_DB_DATA Certs1[];
1160 // /// AUTH_CERT_DB_DATA Certs2[];
1161 // /// ...
1162 // /// AUTH_CERT_DB_DATA Certsn[];
1163 //
1164
1165 @param[in] VariableName Name of authenticated Variable.
1166 @param[in] VendorGuid Vendor GUID of authenticated Variable.
1167 @param[in] Data Pointer to variable "certdb" or "certdbv".
1168 @param[in] DataSize Size of variable "certdb" or "certdbv".
1169 @param[out] CertOffset Offset of matching CertData, from starting of Data.
1170 @param[out] CertDataSize Length of CertData in bytes.
1171 @param[out] CertNodeOffset Offset of matching AUTH_CERT_DB_DATA , from
1172 starting of Data.
1173 @param[out] CertNodeSize Length of AUTH_CERT_DB_DATA in bytes.
1174
1175 @retval EFI_INVALID_PARAMETER Any input parameter is invalid.
1176 @retval EFI_NOT_FOUND Fail to find matching certs.
1177 @retval EFI_SUCCESS Find matching certs and output parameters.
1178
1179 **/
1180 EFI_STATUS
1181 FindCertsFromDb (
1182 IN CHAR16 *VariableName,
1183 IN EFI_GUID *VendorGuid,
1184 IN UINT8 *Data,
1185 IN UINTN DataSize,
1186 OUT UINT32 *CertOffset OPTIONAL,
1187 OUT UINT32 *CertDataSize OPTIONAL,
1188 OUT UINT32 *CertNodeOffset OPTIONAL,
1189 OUT UINT32 *CertNodeSize OPTIONAL
1190 )
1191 {
1192 UINT32 Offset;
1193 AUTH_CERT_DB_DATA *Ptr;
1194 UINT32 CertSize;
1195 UINT32 NameSize;
1196 UINT32 NodeSize;
1197 UINT32 CertDbListSize;
1198
1199 if ((VariableName == NULL) || (VendorGuid == NULL) || (Data == NULL)) {
1200 return EFI_INVALID_PARAMETER;
1201 }
1202
1203 //
1204 // Check whether DataSize matches recorded CertDbListSize.
1205 //
1206 if (DataSize < sizeof (UINT32)) {
1207 return EFI_INVALID_PARAMETER;
1208 }
1209
1210 CertDbListSize = ReadUnaligned32 ((UINT32 *) Data);
1211
1212 if (CertDbListSize != (UINT32) DataSize) {
1213 return EFI_INVALID_PARAMETER;
1214 }
1215
1216 Offset = sizeof (UINT32);
1217
1218 //
1219 // Get corresponding certificates by VendorGuid and VariableName.
1220 //
1221 while (Offset < (UINT32) DataSize) {
1222 Ptr = (AUTH_CERT_DB_DATA *) (Data + Offset);
1223 //
1224 // Check whether VendorGuid matches.
1225 //
1226 if (CompareGuid (&Ptr->VendorGuid, VendorGuid)) {
1227 NodeSize = ReadUnaligned32 (&Ptr->CertNodeSize);
1228 NameSize = ReadUnaligned32 (&Ptr->NameSize);
1229 CertSize = ReadUnaligned32 (&Ptr->CertDataSize);
1230
1231 if (NodeSize != sizeof (EFI_GUID) + sizeof (UINT32) * 3 + CertSize +
1232 sizeof (CHAR16) * NameSize) {
1233 return EFI_INVALID_PARAMETER;
1234 }
1235
1236 Offset = Offset + sizeof (EFI_GUID) + sizeof (UINT32) * 3;
1237 //
1238 // Check whether VariableName matches.
1239 //
1240 if ((NameSize == StrLen (VariableName)) &&
1241 (CompareMem (Data + Offset, VariableName, NameSize * sizeof (CHAR16)) == 0)) {
1242 Offset = Offset + NameSize * sizeof (CHAR16);
1243
1244 if (CertOffset != NULL) {
1245 *CertOffset = Offset;
1246 }
1247
1248 if (CertDataSize != NULL) {
1249 *CertDataSize = CertSize;
1250 }
1251
1252 if (CertNodeOffset != NULL) {
1253 *CertNodeOffset = (UINT32) ((UINT8 *) Ptr - Data);
1254 }
1255
1256 if (CertNodeSize != NULL) {
1257 *CertNodeSize = NodeSize;
1258 }
1259
1260 return EFI_SUCCESS;
1261 } else {
1262 Offset = Offset + NameSize * sizeof (CHAR16) + CertSize;
1263 }
1264 } else {
1265 NodeSize = ReadUnaligned32 (&Ptr->CertNodeSize);
1266 Offset = Offset + NodeSize;
1267 }
1268 }
1269
1270 return EFI_NOT_FOUND;
1271 }
1272
1273 /**
1274 Retrieve signer's certificates for common authenticated variable
1275 by corresponding VariableName and VendorGuid from "certdb"
1276 or "certdbv" according to authenticated variable attributes.
1277
1278 @param[in] VariableName Name of authenticated Variable.
1279 @param[in] VendorGuid Vendor GUID of authenticated Variable.
1280 @param[in] Attributes Attributes of authenticated variable.
1281 @param[out] CertData Pointer to signer's certificates.
1282 @param[out] CertDataSize Length of CertData in bytes.
1283
1284 @retval EFI_INVALID_PARAMETER Any input parameter is invalid.
1285 @retval EFI_NOT_FOUND Fail to find "certdb"/"certdbv" or matching certs.
1286 @retval EFI_SUCCESS Get signer's certificates successfully.
1287
1288 **/
1289 EFI_STATUS
1290 GetCertsFromDb (
1291 IN CHAR16 *VariableName,
1292 IN EFI_GUID *VendorGuid,
1293 IN UINT32 Attributes,
1294 OUT UINT8 **CertData,
1295 OUT UINT32 *CertDataSize
1296 )
1297 {
1298 EFI_STATUS Status;
1299 UINT8 *Data;
1300 UINTN DataSize;
1301 UINT32 CertOffset;
1302 CHAR16 *DbName;
1303
1304 if ((VariableName == NULL) || (VendorGuid == NULL) || (CertData == NULL) || (CertDataSize == NULL)) {
1305 return EFI_INVALID_PARAMETER;
1306 }
1307
1308
1309 if ((Attributes & EFI_VARIABLE_NON_VOLATILE) != 0) {
1310 //
1311 // Get variable "certdb".
1312 //
1313 DbName = EFI_CERT_DB_NAME;
1314 } else {
1315 //
1316 // Get variable "certdbv".
1317 //
1318 DbName = EFI_CERT_DB_VOLATILE_NAME;
1319 }
1320
1321 //
1322 // Get variable "certdb" or "certdbv".
1323 //
1324 Status = AuthServiceInternalFindVariable (
1325 DbName,
1326 &gEfiCertDbGuid,
1327 (VOID **) &Data,
1328 &DataSize
1329 );
1330 if (EFI_ERROR (Status)) {
1331 return Status;
1332 }
1333
1334 if ((DataSize == 0) || (Data == NULL)) {
1335 ASSERT (FALSE);
1336 return EFI_NOT_FOUND;
1337 }
1338
1339 Status = FindCertsFromDb (
1340 VariableName,
1341 VendorGuid,
1342 Data,
1343 DataSize,
1344 &CertOffset,
1345 CertDataSize,
1346 NULL,
1347 NULL
1348 );
1349
1350 if (EFI_ERROR (Status)) {
1351 return Status;
1352 }
1353
1354 *CertData = Data + CertOffset;
1355 return EFI_SUCCESS;
1356 }
1357
1358 /**
1359 Delete matching signer's certificates when deleting common authenticated
1360 variable by corresponding VariableName and VendorGuid from "certdb" or
1361 "certdbv" according to authenticated variable attributes.
1362
1363 @param[in] VariableName Name of authenticated Variable.
1364 @param[in] VendorGuid Vendor GUID of authenticated Variable.
1365 @param[in] Attributes Attributes of authenticated variable.
1366
1367 @retval EFI_INVALID_PARAMETER Any input parameter is invalid.
1368 @retval EFI_NOT_FOUND Fail to find "certdb"/"certdbv" or matching certs.
1369 @retval EFI_OUT_OF_RESOURCES The operation is failed due to lack of resources.
1370 @retval EFI_SUCCESS The operation is completed successfully.
1371
1372 **/
1373 EFI_STATUS
1374 DeleteCertsFromDb (
1375 IN CHAR16 *VariableName,
1376 IN EFI_GUID *VendorGuid,
1377 IN UINT32 Attributes
1378 )
1379 {
1380 EFI_STATUS Status;
1381 UINT8 *Data;
1382 UINTN DataSize;
1383 UINT32 VarAttr;
1384 UINT32 CertNodeOffset;
1385 UINT32 CertNodeSize;
1386 UINT8 *NewCertDb;
1387 UINT32 NewCertDbSize;
1388 CHAR16 *DbName;
1389
1390 if ((VariableName == NULL) || (VendorGuid == NULL)) {
1391 return EFI_INVALID_PARAMETER;
1392 }
1393
1394 if ((Attributes & EFI_VARIABLE_NON_VOLATILE) != 0) {
1395 //
1396 // Get variable "certdb".
1397 //
1398 DbName = EFI_CERT_DB_NAME;
1399 VarAttr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
1400 } else {
1401 //
1402 // Get variable "certdbv".
1403 //
1404 DbName = EFI_CERT_DB_VOLATILE_NAME;
1405 VarAttr = EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
1406 }
1407
1408 Status = AuthServiceInternalFindVariable (
1409 DbName,
1410 &gEfiCertDbGuid,
1411 (VOID **) &Data,
1412 &DataSize
1413 );
1414
1415 if (EFI_ERROR (Status)) {
1416 return Status;
1417 }
1418
1419 if ((DataSize == 0) || (Data == NULL)) {
1420 ASSERT (FALSE);
1421 return EFI_NOT_FOUND;
1422 }
1423
1424 if (DataSize == sizeof (UINT32)) {
1425 //
1426 // There is no certs in "certdb" or "certdbv".
1427 //
1428 return EFI_SUCCESS;
1429 }
1430
1431 //
1432 // Get corresponding cert node from "certdb" or "certdbv".
1433 //
1434 Status = FindCertsFromDb (
1435 VariableName,
1436 VendorGuid,
1437 Data,
1438 DataSize,
1439 NULL,
1440 NULL,
1441 &CertNodeOffset,
1442 &CertNodeSize
1443 );
1444
1445 if (EFI_ERROR (Status)) {
1446 return Status;
1447 }
1448
1449 if (DataSize < (CertNodeOffset + CertNodeSize)) {
1450 return EFI_NOT_FOUND;
1451 }
1452
1453 //
1454 // Construct new data content of variable "certdb" or "certdbv".
1455 //
1456 NewCertDbSize = (UINT32) DataSize - CertNodeSize;
1457 NewCertDb = (UINT8*) mCertDbStore;
1458
1459 //
1460 // Copy the DB entries before deleting node.
1461 //
1462 CopyMem (NewCertDb, Data, CertNodeOffset);
1463 //
1464 // Update CertDbListSize.
1465 //
1466 CopyMem (NewCertDb, &NewCertDbSize, sizeof (UINT32));
1467 //
1468 // Copy the DB entries after deleting node.
1469 //
1470 if (DataSize > (CertNodeOffset + CertNodeSize)) {
1471 CopyMem (
1472 NewCertDb + CertNodeOffset,
1473 Data + CertNodeOffset + CertNodeSize,
1474 DataSize - CertNodeOffset - CertNodeSize
1475 );
1476 }
1477
1478 //
1479 // Set "certdb" or "certdbv".
1480 //
1481 Status = AuthServiceInternalUpdateVariable (
1482 DbName,
1483 &gEfiCertDbGuid,
1484 NewCertDb,
1485 NewCertDbSize,
1486 VarAttr
1487 );
1488
1489 return Status;
1490 }
1491
1492 /**
1493 Insert signer's certificates for common authenticated variable with VariableName
1494 and VendorGuid in AUTH_CERT_DB_DATA to "certdb" or "certdbv" according to
1495 time based authenticated variable attributes. CertData is the SHA256 digest of
1496 SignerCert CommonName + TopLevelCert tbsCertificate.
1497
1498 @param[in] VariableName Name of authenticated Variable.
1499 @param[in] VendorGuid Vendor GUID of authenticated Variable.
1500 @param[in] Attributes Attributes of authenticated variable.
1501 @param[in] SignerCert Signer certificate data.
1502 @param[in] SignerCertSize Length of signer certificate.
1503 @param[in] TopLevelCert Top-level certificate data.
1504 @param[in] TopLevelCertSize Length of top-level certificate.
1505
1506 @retval EFI_INVALID_PARAMETER Any input parameter is invalid.
1507 @retval EFI_ACCESS_DENIED An AUTH_CERT_DB_DATA entry with same VariableName
1508 and VendorGuid already exists.
1509 @retval EFI_OUT_OF_RESOURCES The operation is failed due to lack of resources.
1510 @retval EFI_SUCCESS Insert an AUTH_CERT_DB_DATA entry to "certdb" or "certdbv"
1511
1512 **/
1513 EFI_STATUS
1514 InsertCertsToDb (
1515 IN CHAR16 *VariableName,
1516 IN EFI_GUID *VendorGuid,
1517 IN UINT32 Attributes,
1518 IN UINT8 *SignerCert,
1519 IN UINTN SignerCertSize,
1520 IN UINT8 *TopLevelCert,
1521 IN UINTN TopLevelCertSize
1522 )
1523 {
1524 EFI_STATUS Status;
1525 UINT8 *Data;
1526 UINTN DataSize;
1527 UINT32 VarAttr;
1528 UINT8 *NewCertDb;
1529 UINT32 NewCertDbSize;
1530 UINT32 CertNodeSize;
1531 UINT32 NameSize;
1532 UINT32 CertDataSize;
1533 AUTH_CERT_DB_DATA *Ptr;
1534 CHAR16 *DbName;
1535 UINT8 Sha256Digest[SHA256_DIGEST_SIZE];
1536
1537 if ((VariableName == NULL) || (VendorGuid == NULL) || (SignerCert == NULL) ||(TopLevelCert == NULL)) {
1538 return EFI_INVALID_PARAMETER;
1539 }
1540
1541 if ((Attributes & EFI_VARIABLE_NON_VOLATILE) != 0) {
1542 //
1543 // Get variable "certdb".
1544 //
1545 DbName = EFI_CERT_DB_NAME;
1546 VarAttr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
1547 } else {
1548 //
1549 // Get variable "certdbv".
1550 //
1551 DbName = EFI_CERT_DB_VOLATILE_NAME;
1552 VarAttr = EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
1553 }
1554
1555 //
1556 // Get variable "certdb" or "certdbv".
1557 //
1558 Status = AuthServiceInternalFindVariable (
1559 DbName,
1560 &gEfiCertDbGuid,
1561 (VOID **) &Data,
1562 &DataSize
1563 );
1564 if (EFI_ERROR (Status)) {
1565 return Status;
1566 }
1567
1568 if ((DataSize == 0) || (Data == NULL)) {
1569 ASSERT (FALSE);
1570 return EFI_NOT_FOUND;
1571 }
1572
1573 //
1574 // Find whether matching cert node already exists in "certdb" or "certdbv".
1575 // If yes return error.
1576 //
1577 Status = FindCertsFromDb (
1578 VariableName,
1579 VendorGuid,
1580 Data,
1581 DataSize,
1582 NULL,
1583 NULL,
1584 NULL,
1585 NULL
1586 );
1587
1588 if (!EFI_ERROR (Status)) {
1589 ASSERT (FALSE);
1590 return EFI_ACCESS_DENIED;
1591 }
1592
1593 //
1594 // Construct new data content of variable "certdb" or "certdbv".
1595 //
1596 NameSize = (UINT32) StrLen (VariableName);
1597 CertDataSize = sizeof(Sha256Digest);
1598 CertNodeSize = sizeof (AUTH_CERT_DB_DATA) + (UINT32) CertDataSize + NameSize * sizeof (CHAR16);
1599 NewCertDbSize = (UINT32) DataSize + CertNodeSize;
1600 if (NewCertDbSize > mMaxCertDbSize) {
1601 return EFI_OUT_OF_RESOURCES;
1602 }
1603
1604 Status = CalculatePrivAuthVarSignChainSHA256Digest(
1605 SignerCert,
1606 SignerCertSize,
1607 TopLevelCert,
1608 TopLevelCertSize,
1609 Sha256Digest
1610 );
1611 if (EFI_ERROR (Status)) {
1612 return Status;
1613 }
1614
1615 NewCertDb = (UINT8*) mCertDbStore;
1616
1617 //
1618 // Copy the DB entries before inserting node.
1619 //
1620 CopyMem (NewCertDb, Data, DataSize);
1621 //
1622 // Update CertDbListSize.
1623 //
1624 CopyMem (NewCertDb, &NewCertDbSize, sizeof (UINT32));
1625 //
1626 // Construct new cert node.
1627 //
1628 Ptr = (AUTH_CERT_DB_DATA *) (NewCertDb + DataSize);
1629 CopyGuid (&Ptr->VendorGuid, VendorGuid);
1630 CopyMem (&Ptr->CertNodeSize, &CertNodeSize, sizeof (UINT32));
1631 CopyMem (&Ptr->NameSize, &NameSize, sizeof (UINT32));
1632 CopyMem (&Ptr->CertDataSize, &CertDataSize, sizeof (UINT32));
1633
1634 CopyMem (
1635 (UINT8 *) Ptr + sizeof (AUTH_CERT_DB_DATA),
1636 VariableName,
1637 NameSize * sizeof (CHAR16)
1638 );
1639
1640 CopyMem (
1641 (UINT8 *) Ptr + sizeof (AUTH_CERT_DB_DATA) + NameSize * sizeof (CHAR16),
1642 Sha256Digest,
1643 CertDataSize
1644 );
1645
1646 //
1647 // Set "certdb" or "certdbv".
1648 //
1649 Status = AuthServiceInternalUpdateVariable (
1650 DbName,
1651 &gEfiCertDbGuid,
1652 NewCertDb,
1653 NewCertDbSize,
1654 VarAttr
1655 );
1656
1657 return Status;
1658 }
1659
1660 /**
1661 Clean up signer's certificates for common authenticated variable
1662 by corresponding VariableName and VendorGuid from "certdb".
1663 System may break down during Timebased Variable update & certdb update,
1664 make them inconsistent, this function is called in AuthVariable Init
1665 to ensure consistency.
1666
1667 @retval EFI_NOT_FOUND Fail to find variable "certdb".
1668 @retval EFI_OUT_OF_RESOURCES The operation is failed due to lack of resources.
1669 @retval EFI_SUCCESS The operation is completed successfully.
1670
1671 **/
1672 EFI_STATUS
1673 CleanCertsFromDb (
1674 VOID
1675 )
1676 {
1677 UINT32 Offset;
1678 AUTH_CERT_DB_DATA *Ptr;
1679 UINT32 NameSize;
1680 UINT32 NodeSize;
1681 CHAR16 *VariableName;
1682 EFI_STATUS Status;
1683 BOOLEAN CertCleaned;
1684 UINT8 *Data;
1685 UINTN DataSize;
1686 EFI_GUID AuthVarGuid;
1687 AUTH_VARIABLE_INFO AuthVariableInfo;
1688
1689 Status = EFI_SUCCESS;
1690
1691 //
1692 // Get corresponding certificates by VendorGuid and VariableName.
1693 //
1694 do {
1695 CertCleaned = FALSE;
1696
1697 //
1698 // Get latest variable "certdb"
1699 //
1700 Status = AuthServiceInternalFindVariable (
1701 EFI_CERT_DB_NAME,
1702 &gEfiCertDbGuid,
1703 (VOID **) &Data,
1704 &DataSize
1705 );
1706 if (EFI_ERROR (Status)) {
1707 return Status;
1708 }
1709
1710 if ((DataSize == 0) || (Data == NULL)) {
1711 ASSERT (FALSE);
1712 return EFI_NOT_FOUND;
1713 }
1714
1715 Offset = sizeof (UINT32);
1716
1717 while (Offset < (UINT32) DataSize) {
1718 Ptr = (AUTH_CERT_DB_DATA *) (Data + Offset);
1719 NodeSize = ReadUnaligned32 (&Ptr->CertNodeSize);
1720 NameSize = ReadUnaligned32 (&Ptr->NameSize);
1721
1722 //
1723 // Get VarName tailed with '\0'
1724 //
1725 VariableName = AllocateZeroPool((NameSize + 1) * sizeof(CHAR16));
1726 if (VariableName == NULL) {
1727 return EFI_OUT_OF_RESOURCES;
1728 }
1729 CopyMem (VariableName, (UINT8 *) Ptr + sizeof (AUTH_CERT_DB_DATA), NameSize * sizeof(CHAR16));
1730 //
1731 // Keep VarGuid aligned
1732 //
1733 CopyMem (&AuthVarGuid, &Ptr->VendorGuid, sizeof(EFI_GUID));
1734
1735 //
1736 // Find corresponding time auth variable
1737 //
1738 ZeroMem (&AuthVariableInfo, sizeof (AuthVariableInfo));
1739 Status = mAuthVarLibContextIn->FindVariable (
1740 VariableName,
1741 &AuthVarGuid,
1742 &AuthVariableInfo
1743 );
1744
1745 if (EFI_ERROR(Status) || (AuthVariableInfo.Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) == 0) {
1746 //
1747 // While cleaning certdb, always delete the variable in certdb regardless of it attributes.
1748 //
1749 Status = DeleteCertsFromDb(
1750 VariableName,
1751 &AuthVarGuid,
1752 AuthVariableInfo.Attributes | EFI_VARIABLE_NON_VOLATILE
1753 );
1754 CertCleaned = TRUE;
1755 DEBUG((DEBUG_INFO, "Recovery!! Cert for Auth Variable %s Guid %g is removed for consistency\n", VariableName, &AuthVarGuid));
1756 FreePool(VariableName);
1757 break;
1758 }
1759
1760 FreePool(VariableName);
1761 Offset = Offset + NodeSize;
1762 }
1763 } while (CertCleaned);
1764
1765 return Status;
1766 }
1767
1768 /**
1769 Process variable with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set
1770
1771 Caution: This function may receive untrusted input.
1772 This function may be invoked in SMM mode, and datasize and data are external input.
1773 This function will do basic validation, before parse the data.
1774 This function will parse the authentication carefully to avoid security issues, like
1775 buffer overflow, integer overflow.
1776
1777 @param[in] VariableName Name of Variable to be found.
1778 @param[in] VendorGuid Variable vendor GUID.
1779 @param[in] Data Data pointer.
1780 @param[in] DataSize Size of Data found. If size is less than the
1781 data, this value contains the required size.
1782 @param[in] Attributes Attribute value of the variable.
1783 @param[in] AuthVarType Verify against PK, KEK database, private database or certificate in data payload.
1784 @param[in] OrgTimeStamp Pointer to original time stamp,
1785 original variable is not found if NULL.
1786 @param[out] VarPayloadPtr Pointer to variable payload address.
1787 @param[out] VarPayloadSize Pointer to variable payload size.
1788
1789 @retval EFI_INVALID_PARAMETER Invalid parameter.
1790 @retval EFI_SECURITY_VIOLATION The variable does NOT pass the validation
1791 check carried out by the firmware.
1792 @retval EFI_OUT_OF_RESOURCES Failed to process variable due to lack
1793 of resources.
1794 @retval EFI_SUCCESS Variable pass validation successfully.
1795
1796 **/
1797 EFI_STATUS
1798 VerifyTimeBasedPayload (
1799 IN CHAR16 *VariableName,
1800 IN EFI_GUID *VendorGuid,
1801 IN VOID *Data,
1802 IN UINTN DataSize,
1803 IN UINT32 Attributes,
1804 IN AUTHVAR_TYPE AuthVarType,
1805 IN EFI_TIME *OrgTimeStamp,
1806 OUT UINT8 **VarPayloadPtr,
1807 OUT UINTN *VarPayloadSize
1808 )
1809 {
1810 EFI_VARIABLE_AUTHENTICATION_2 *CertData;
1811 UINT8 *SigData;
1812 UINT32 SigDataSize;
1813 UINT8 *PayloadPtr;
1814 UINTN PayloadSize;
1815 UINT32 Attr;
1816 BOOLEAN VerifyStatus;
1817 EFI_STATUS Status;
1818 EFI_SIGNATURE_LIST *CertList;
1819 EFI_SIGNATURE_DATA *Cert;
1820 UINTN Index;
1821 UINTN CertCount;
1822 UINT32 KekDataSize;
1823 UINT8 *NewData;
1824 UINTN NewDataSize;
1825 UINT8 *Buffer;
1826 UINTN Length;
1827 UINT8 *TopLevelCert;
1828 UINTN TopLevelCertSize;
1829 UINT8 *TrustedCert;
1830 UINTN TrustedCertSize;
1831 UINT8 *SignerCerts;
1832 UINTN CertStackSize;
1833 UINT8 *CertsInCertDb;
1834 UINT32 CertsSizeinDb;
1835 UINT8 Sha256Digest[SHA256_DIGEST_SIZE];
1836 EFI_CERT_DATA *CertDataPtr;
1837
1838 //
1839 // 1. TopLevelCert is the top-level issuer certificate in signature Signer Cert Chain
1840 // 2. TrustedCert is the certificate which firmware trusts. It could be saved in protected
1841 // storage or PK payload on PK init
1842 //
1843 VerifyStatus = FALSE;
1844 CertData = NULL;
1845 NewData = NULL;
1846 Attr = Attributes;
1847 SignerCerts = NULL;
1848 TopLevelCert = NULL;
1849 CertsInCertDb = NULL;
1850 CertDataPtr = NULL;
1851
1852 //
1853 // When the attribute EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS is
1854 // set, then the Data buffer shall begin with an instance of a complete (and serialized)
1855 // EFI_VARIABLE_AUTHENTICATION_2 descriptor. The descriptor shall be followed by the new
1856 // variable value and DataSize shall reflect the combined size of the descriptor and the new
1857 // variable value. The authentication descriptor is not part of the variable data and is not
1858 // returned by subsequent calls to GetVariable().
1859 //
1860 CertData = (EFI_VARIABLE_AUTHENTICATION_2 *) Data;
1861
1862 //
1863 // Verify that Pad1, Nanosecond, TimeZone, Daylight and Pad2 components of the
1864 // TimeStamp value are set to zero.
1865 //
1866 if ((CertData->TimeStamp.Pad1 != 0) ||
1867 (CertData->TimeStamp.Nanosecond != 0) ||
1868 (CertData->TimeStamp.TimeZone != 0) ||
1869 (CertData->TimeStamp.Daylight != 0) ||
1870 (CertData->TimeStamp.Pad2 != 0)) {
1871 return EFI_SECURITY_VIOLATION;
1872 }
1873
1874 if ((OrgTimeStamp != NULL) && ((Attributes & EFI_VARIABLE_APPEND_WRITE) == 0)) {
1875 if (AuthServiceInternalCompareTimeStamp (&CertData->TimeStamp, OrgTimeStamp)) {
1876 //
1877 // TimeStamp check fail, suspicious replay attack, return EFI_SECURITY_VIOLATION.
1878 //
1879 return EFI_SECURITY_VIOLATION;
1880 }
1881 }
1882
1883 //
1884 // wCertificateType should be WIN_CERT_TYPE_EFI_GUID.
1885 // Cert type should be EFI_CERT_TYPE_PKCS7_GUID.
1886 //
1887 if ((CertData->AuthInfo.Hdr.wCertificateType != WIN_CERT_TYPE_EFI_GUID) ||
1888 !CompareGuid (&CertData->AuthInfo.CertType, &gEfiCertPkcs7Guid)) {
1889 //
1890 // Invalid AuthInfo type, return EFI_SECURITY_VIOLATION.
1891 //
1892 return EFI_SECURITY_VIOLATION;
1893 }
1894
1895 //
1896 // Find out Pkcs7 SignedData which follows the EFI_VARIABLE_AUTHENTICATION_2 descriptor.
1897 // AuthInfo.Hdr.dwLength is the length of the entire certificate, including the length of the header.
1898 //
1899 SigData = CertData->AuthInfo.CertData;
1900 SigDataSize = CertData->AuthInfo.Hdr.dwLength - (UINT32) (OFFSET_OF (WIN_CERTIFICATE_UEFI_GUID, CertData));
1901
1902 //
1903 // SignedData.digestAlgorithms shall contain the digest algorithm used when preparing the
1904 // signature. Only a digest algorithm of SHA-256 is accepted.
1905 //
1906 // According to PKCS#7 Definition:
1907 // SignedData ::= SEQUENCE {
1908 // version Version,
1909 // digestAlgorithms DigestAlgorithmIdentifiers,
1910 // contentInfo ContentInfo,
1911 // .... }
1912 // The DigestAlgorithmIdentifiers can be used to determine the hash algorithm
1913 // in VARIABLE_AUTHENTICATION_2 descriptor.
1914 // This field has the fixed offset (+13) and be calculated based on two bytes of length encoding.
1915 //
1916 if ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) {
1917 if (SigDataSize >= (13 + sizeof (mSha256OidValue))) {
1918 if (((*(SigData + 1) & TWO_BYTE_ENCODE) != TWO_BYTE_ENCODE) ||
1919 (CompareMem (SigData + 13, &mSha256OidValue, sizeof (mSha256OidValue)) != 0)) {
1920 return EFI_SECURITY_VIOLATION;
1921 }
1922 }
1923 }
1924
1925 //
1926 // Find out the new data payload which follows Pkcs7 SignedData directly.
1927 //
1928 PayloadPtr = SigData + SigDataSize;
1929 PayloadSize = DataSize - OFFSET_OF_AUTHINFO2_CERT_DATA - (UINTN) SigDataSize;
1930
1931 // If the VariablePolicy engine is disabled, allow deletion of any authenticated variables.
1932 if (PayloadSize == 0 && (Attributes & EFI_VARIABLE_APPEND_WRITE) == 0 && !IsVariablePolicyEnabled()) {
1933 VerifyStatus = TRUE;
1934 goto Exit;
1935 }
1936
1937 //
1938 // Construct a serialization buffer of the values of the VariableName, VendorGuid and Attributes
1939 // parameters of the SetVariable() call and the TimeStamp component of the
1940 // EFI_VARIABLE_AUTHENTICATION_2 descriptor followed by the variable's new value
1941 // i.e. (VariableName, VendorGuid, Attributes, TimeStamp, Data)
1942 //
1943 NewDataSize = PayloadSize + sizeof (EFI_TIME) + sizeof (UINT32) +
1944 sizeof (EFI_GUID) + StrSize (VariableName) - sizeof (CHAR16);
1945
1946 //
1947 // Here is to reuse scratch data area(at the end of volatile variable store)
1948 // to reduce SMRAM consumption for SMM variable driver.
1949 // The scratch buffer is enough to hold the serialized data and safe to use,
1950 // because it is only used at here to do verification temporarily first
1951 // and then used in UpdateVariable() for a time based auth variable set.
1952 //
1953 Status = mAuthVarLibContextIn->GetScratchBuffer (&NewDataSize, (VOID **) &NewData);
1954 if (EFI_ERROR (Status)) {
1955 return EFI_OUT_OF_RESOURCES;
1956 }
1957
1958 Buffer = NewData;
1959 Length = StrLen (VariableName) * sizeof (CHAR16);
1960 CopyMem (Buffer, VariableName, Length);
1961 Buffer += Length;
1962
1963 Length = sizeof (EFI_GUID);
1964 CopyMem (Buffer, VendorGuid, Length);
1965 Buffer += Length;
1966
1967 Length = sizeof (UINT32);
1968 CopyMem (Buffer, &Attr, Length);
1969 Buffer += Length;
1970
1971 Length = sizeof (EFI_TIME);
1972 CopyMem (Buffer, &CertData->TimeStamp, Length);
1973 Buffer += Length;
1974
1975 CopyMem (Buffer, PayloadPtr, PayloadSize);
1976
1977 if (AuthVarType == AuthVarTypePk) {
1978 //
1979 // Verify that the signature has been made with the current Platform Key (no chaining for PK).
1980 // First, get signer's certificates from SignedData.
1981 //
1982 VerifyStatus = Pkcs7GetSigners (
1983 SigData,
1984 SigDataSize,
1985 &SignerCerts,
1986 &CertStackSize,
1987 &TopLevelCert,
1988 &TopLevelCertSize
1989 );
1990 if (!VerifyStatus) {
1991 goto Exit;
1992 }
1993
1994 //
1995 // Second, get the current platform key from variable. Check whether it's identical with signer's certificates
1996 // in SignedData. If not, return error immediately.
1997 //
1998 Status = AuthServiceInternalFindVariable (
1999 EFI_PLATFORM_KEY_NAME,
2000 &gEfiGlobalVariableGuid,
2001 &Data,
2002 &DataSize
2003 );
2004 if (EFI_ERROR (Status)) {
2005 VerifyStatus = FALSE;
2006 goto Exit;
2007 }
2008 CertList = (EFI_SIGNATURE_LIST *) Data;
2009 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
2010 if ((TopLevelCertSize != (CertList->SignatureSize - (sizeof (EFI_SIGNATURE_DATA) - 1))) ||
2011 (CompareMem (Cert->SignatureData, TopLevelCert, TopLevelCertSize) != 0)) {
2012 VerifyStatus = FALSE;
2013 goto Exit;
2014 }
2015
2016 //
2017 // Verify Pkcs7 SignedData via Pkcs7Verify library.
2018 //
2019 VerifyStatus = Pkcs7Verify (
2020 SigData,
2021 SigDataSize,
2022 TopLevelCert,
2023 TopLevelCertSize,
2024 NewData,
2025 NewDataSize
2026 );
2027
2028 } else if (AuthVarType == AuthVarTypeKek) {
2029
2030 //
2031 // Get KEK database from variable.
2032 //
2033 Status = AuthServiceInternalFindVariable (
2034 EFI_KEY_EXCHANGE_KEY_NAME,
2035 &gEfiGlobalVariableGuid,
2036 &Data,
2037 &DataSize
2038 );
2039 if (EFI_ERROR (Status)) {
2040 return Status;
2041 }
2042
2043 //
2044 // Ready to verify Pkcs7 SignedData. Go through KEK Signature Database to find out X.509 CertList.
2045 //
2046 KekDataSize = (UINT32) DataSize;
2047 CertList = (EFI_SIGNATURE_LIST *) Data;
2048 while ((KekDataSize > 0) && (KekDataSize >= CertList->SignatureListSize)) {
2049 if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {
2050 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
2051 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
2052 for (Index = 0; Index < CertCount; Index++) {
2053 //
2054 // Iterate each Signature Data Node within this CertList for a verify
2055 //
2056 TrustedCert = Cert->SignatureData;
2057 TrustedCertSize = CertList->SignatureSize - (sizeof (EFI_SIGNATURE_DATA) - 1);
2058
2059 //
2060 // Verify Pkcs7 SignedData via Pkcs7Verify library.
2061 //
2062 VerifyStatus = Pkcs7Verify (
2063 SigData,
2064 SigDataSize,
2065 TrustedCert,
2066 TrustedCertSize,
2067 NewData,
2068 NewDataSize
2069 );
2070 if (VerifyStatus) {
2071 goto Exit;
2072 }
2073 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);
2074 }
2075 }
2076 KekDataSize -= CertList->SignatureListSize;
2077 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
2078 }
2079 } else if (AuthVarType == AuthVarTypePriv) {
2080
2081 //
2082 // Process common authenticated variable except PK/KEK/DB/DBX/DBT.
2083 // Get signer's certificates from SignedData.
2084 //
2085 VerifyStatus = Pkcs7GetSigners (
2086 SigData,
2087 SigDataSize,
2088 &SignerCerts,
2089 &CertStackSize,
2090 &TopLevelCert,
2091 &TopLevelCertSize
2092 );
2093 if (!VerifyStatus) {
2094 goto Exit;
2095 }
2096
2097 //
2098 // Get previously stored signer's certificates from certdb or certdbv for existing
2099 // variable. Check whether they are identical with signer's certificates
2100 // in SignedData. If not, return error immediately.
2101 //
2102 if (OrgTimeStamp != NULL) {
2103 VerifyStatus = FALSE;
2104
2105 Status = GetCertsFromDb (VariableName, VendorGuid, Attributes, &CertsInCertDb, &CertsSizeinDb);
2106 if (EFI_ERROR (Status)) {
2107 goto Exit;
2108 }
2109
2110 if (CertsSizeinDb == SHA256_DIGEST_SIZE) {
2111 //
2112 // Check hash of signer cert CommonName + Top-level issuer tbsCertificate against data in CertDb
2113 //
2114 CertDataPtr = (EFI_CERT_DATA *)(SignerCerts + 1);
2115 Status = CalculatePrivAuthVarSignChainSHA256Digest(
2116 CertDataPtr->CertDataBuffer,
2117 ReadUnaligned32 ((UINT32 *)&(CertDataPtr->CertDataLength)),
2118 TopLevelCert,
2119 TopLevelCertSize,
2120 Sha256Digest
2121 );
2122 if (EFI_ERROR(Status) || CompareMem (Sha256Digest, CertsInCertDb, CertsSizeinDb) != 0){
2123 goto Exit;
2124 }
2125 } else {
2126 //
2127 // Keep backward compatible with previous solution which saves whole signer certs stack in CertDb
2128 //
2129 if ((CertStackSize != CertsSizeinDb) ||
2130 (CompareMem (SignerCerts, CertsInCertDb, CertsSizeinDb) != 0)) {
2131 goto Exit;
2132 }
2133 }
2134 }
2135
2136 VerifyStatus = Pkcs7Verify (
2137 SigData,
2138 SigDataSize,
2139 TopLevelCert,
2140 TopLevelCertSize,
2141 NewData,
2142 NewDataSize
2143 );
2144 if (!VerifyStatus) {
2145 goto Exit;
2146 }
2147
2148 if ((OrgTimeStamp == NULL) && (PayloadSize != 0)) {
2149 //
2150 // When adding a new common authenticated variable, always save Hash of cn of signer cert + tbsCertificate of Top-level issuer
2151 //
2152 CertDataPtr = (EFI_CERT_DATA *)(SignerCerts + 1);
2153 Status = InsertCertsToDb (
2154 VariableName,
2155 VendorGuid,
2156 Attributes,
2157 CertDataPtr->CertDataBuffer,
2158 ReadUnaligned32 ((UINT32 *)&(CertDataPtr->CertDataLength)),
2159 TopLevelCert,
2160 TopLevelCertSize
2161 );
2162 if (EFI_ERROR (Status)) {
2163 VerifyStatus = FALSE;
2164 goto Exit;
2165 }
2166 }
2167 } else if (AuthVarType == AuthVarTypePayload) {
2168 CertList = (EFI_SIGNATURE_LIST *) PayloadPtr;
2169 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
2170 TrustedCert = Cert->SignatureData;
2171 TrustedCertSize = CertList->SignatureSize - (sizeof (EFI_SIGNATURE_DATA) - 1);
2172 //
2173 // Verify Pkcs7 SignedData via Pkcs7Verify library.
2174 //
2175 VerifyStatus = Pkcs7Verify (
2176 SigData,
2177 SigDataSize,
2178 TrustedCert,
2179 TrustedCertSize,
2180 NewData,
2181 NewDataSize
2182 );
2183 } else {
2184 return EFI_SECURITY_VIOLATION;
2185 }
2186
2187 Exit:
2188
2189 if (AuthVarType == AuthVarTypePk || AuthVarType == AuthVarTypePriv) {
2190 if (TopLevelCert != NULL) {
2191 Pkcs7FreeSigners (TopLevelCert);
2192 }
2193 if (SignerCerts != NULL) {
2194 Pkcs7FreeSigners (SignerCerts);
2195 }
2196 }
2197
2198 if (!VerifyStatus) {
2199 return EFI_SECURITY_VIOLATION;
2200 }
2201
2202 Status = CheckSignatureListFormat(VariableName, VendorGuid, PayloadPtr, PayloadSize);
2203 if (EFI_ERROR (Status)) {
2204 return Status;
2205 }
2206
2207 *VarPayloadPtr = PayloadPtr;
2208 *VarPayloadSize = PayloadSize;
2209
2210 return EFI_SUCCESS;
2211 }
2212
2213 /**
2214 Process variable with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set
2215
2216 Caution: This function may receive untrusted input.
2217 This function may be invoked in SMM mode, and datasize and data are external input.
2218 This function will do basic validation, before parse the data.
2219 This function will parse the authentication carefully to avoid security issues, like
2220 buffer overflow, integer overflow.
2221
2222 @param[in] VariableName Name of Variable to be found.
2223 @param[in] VendorGuid Variable vendor GUID.
2224 @param[in] Data Data pointer.
2225 @param[in] DataSize Size of Data found. If size is less than the
2226 data, this value contains the required size.
2227 @param[in] Attributes Attribute value of the variable.
2228 @param[in] AuthVarType Verify against PK, KEK database, private database or certificate in data payload.
2229 @param[out] VarDel Delete the variable or not.
2230
2231 @retval EFI_INVALID_PARAMETER Invalid parameter.
2232 @retval EFI_SECURITY_VIOLATION The variable does NOT pass the validation
2233 check carried out by the firmware.
2234 @retval EFI_OUT_OF_RESOURCES Failed to process variable due to lack
2235 of resources.
2236 @retval EFI_SUCCESS Variable pass validation successfully.
2237
2238 **/
2239 EFI_STATUS
2240 VerifyTimeBasedPayloadAndUpdate (
2241 IN CHAR16 *VariableName,
2242 IN EFI_GUID *VendorGuid,
2243 IN VOID *Data,
2244 IN UINTN DataSize,
2245 IN UINT32 Attributes,
2246 IN AUTHVAR_TYPE AuthVarType,
2247 OUT BOOLEAN *VarDel
2248 )
2249 {
2250 EFI_STATUS Status;
2251 EFI_STATUS FindStatus;
2252 UINT8 *PayloadPtr;
2253 UINTN PayloadSize;
2254 EFI_VARIABLE_AUTHENTICATION_2 *CertData;
2255 AUTH_VARIABLE_INFO OrgVariableInfo;
2256 BOOLEAN IsDel;
2257
2258 ZeroMem (&OrgVariableInfo, sizeof (OrgVariableInfo));
2259 FindStatus = mAuthVarLibContextIn->FindVariable (
2260 VariableName,
2261 VendorGuid,
2262 &OrgVariableInfo
2263 );
2264
2265 Status = VerifyTimeBasedPayload (
2266 VariableName,
2267 VendorGuid,
2268 Data,
2269 DataSize,
2270 Attributes,
2271 AuthVarType,
2272 (!EFI_ERROR (FindStatus)) ? OrgVariableInfo.TimeStamp : NULL,
2273 &PayloadPtr,
2274 &PayloadSize
2275 );
2276 if (EFI_ERROR (Status)) {
2277 return Status;
2278 }
2279
2280 if (!EFI_ERROR(FindStatus)
2281 && (PayloadSize == 0)
2282 && ((Attributes & EFI_VARIABLE_APPEND_WRITE) == 0)) {
2283 IsDel = TRUE;
2284 } else {
2285 IsDel = FALSE;
2286 }
2287
2288 CertData = (EFI_VARIABLE_AUTHENTICATION_2 *) Data;
2289
2290 //
2291 // Final step: Update/Append Variable if it pass Pkcs7Verify
2292 //
2293 Status = AuthServiceInternalUpdateVariableWithTimeStamp (
2294 VariableName,
2295 VendorGuid,
2296 PayloadPtr,
2297 PayloadSize,
2298 Attributes,
2299 &CertData->TimeStamp
2300 );
2301
2302 //
2303 // Delete signer's certificates when delete the common authenticated variable.
2304 //
2305 if (IsDel && AuthVarType == AuthVarTypePriv && !EFI_ERROR(Status) ) {
2306 Status = DeleteCertsFromDb (VariableName, VendorGuid, Attributes);
2307 }
2308
2309 if (VarDel != NULL) {
2310 if (IsDel && !EFI_ERROR(Status)) {
2311 *VarDel = TRUE;
2312 } else {
2313 *VarDel = FALSE;
2314 }
2315 }
2316
2317 return Status;
2318 }
EFI Development Kit II mirror for PVE