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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 //
185 // For variables with formatted as EFI_SIGNATURE_LIST, the driver shall not perform an append of
186 // EFI_SIGNATURE_DATA values that are already part of the existing variable value.
187 //
188 FilterSignatureList (
189 OrgData,
190 OrgDataSize,
191 Data,
192 &DataSize
193 );
194 }
195 }
196
197 ZeroMem (&AuthVariableInfo, sizeof (AuthVariableInfo));
198 AuthVariableInfo.VariableName = VariableName;
199 AuthVariableInfo.VendorGuid = VendorGuid;
200 AuthVariableInfo.Data = Data;
201 AuthVariableInfo.DataSize = DataSize;
202 AuthVariableInfo.Attributes = Attributes;
203 AuthVariableInfo.TimeStamp = TimeStamp;
204 return mAuthVarLibContextIn->UpdateVariable (
205 &AuthVariableInfo
206 );
207 }
208
209 /**
210 Determine whether this operation needs a physical present user.
211
212 @param[in] VariableName Name of the Variable.
213 @param[in] VendorGuid GUID of the Variable.
214
215 @retval TRUE This variable is protected, only a physical present user could set this variable.
216 @retval FALSE This variable is not protected.
217
218 **/
219 BOOLEAN
220 NeedPhysicallyPresent (
221 IN CHAR16 *VariableName,
222 IN EFI_GUID *VendorGuid
223 )
224 {
225 // If the VariablePolicy engine is disabled, allow deletion of any authenticated variables.
226 if (IsVariablePolicyEnabled ()) {
227 if ( (CompareGuid (VendorGuid, &gEfiSecureBootEnableDisableGuid) && (StrCmp (VariableName, EFI_SECURE_BOOT_ENABLE_NAME) == 0))
228 || (CompareGuid (VendorGuid, &gEfiCustomModeEnableGuid) && (StrCmp (VariableName, EFI_CUSTOM_MODE_NAME) == 0)))
229 {
230 return TRUE;
231 }
232 }
233
234 return FALSE;
235 }
236
237 /**
238 Determine whether the platform is operating in Custom Secure Boot mode.
239
240 @retval TRUE The platform is operating in Custom mode.
241 @retval FALSE The platform is operating in Standard mode.
242
243 **/
244 BOOLEAN
245 InCustomMode (
246 VOID
247 )
248 {
249 EFI_STATUS Status;
250 VOID *Data;
251 UINTN DataSize;
252
253 Status = AuthServiceInternalFindVariable (EFI_CUSTOM_MODE_NAME, &gEfiCustomModeEnableGuid, &Data, &DataSize);
254 if (!EFI_ERROR (Status) && (*(UINT8 *)Data == CUSTOM_SECURE_BOOT_MODE)) {
255 return TRUE;
256 }
257
258 return FALSE;
259 }
260
261 /**
262 Update platform mode.
263
264 @param[in] Mode SETUP_MODE or USER_MODE.
265
266 @return EFI_INVALID_PARAMETER Invalid parameter.
267 @return EFI_SUCCESS Update platform mode successfully.
268
269 **/
270 EFI_STATUS
271 UpdatePlatformMode (
272 IN UINT32 Mode
273 )
274 {
275 EFI_STATUS Status;
276 VOID *Data;
277 UINTN DataSize;
278 UINT8 SecureBootMode;
279 UINT8 SecureBootEnable;
280 UINTN VariableDataSize;
281
282 Status = AuthServiceInternalFindVariable (
283 EFI_SETUP_MODE_NAME,
284 &gEfiGlobalVariableGuid,
285 &Data,
286 &DataSize
287 );
288 if (EFI_ERROR (Status)) {
289 return Status;
290 }
291
292 //
293 // Update the value of SetupMode variable by a simple mem copy, this could avoid possible
294 // variable storage reclaim at runtime.
295 //
296 mPlatformMode = (UINT8)Mode;
297 CopyMem (Data, &mPlatformMode, sizeof (UINT8));
298
299 if (mAuthVarLibContextIn->AtRuntime ()) {
300 //
301 // SecureBoot Variable indicates whether the platform firmware is operating
302 // in Secure boot mode (1) or not (0), so we should not change SecureBoot
303 // Variable in runtime.
304 //
305 return Status;
306 }
307
308 //
309 // Check "SecureBoot" variable's existence.
310 // If it doesn't exist, firmware has no capability to perform driver signing verification,
311 // then set "SecureBoot" to 0.
312 //
313 Status = AuthServiceInternalFindVariable (
314 EFI_SECURE_BOOT_MODE_NAME,
315 &gEfiGlobalVariableGuid,
316 &Data,
317 &DataSize
318 );
319 //
320 // If "SecureBoot" variable exists, then check "SetupMode" variable update.
321 // If "SetupMode" variable is USER_MODE, "SecureBoot" variable is set to 1.
322 // If "SetupMode" variable is SETUP_MODE, "SecureBoot" variable is set to 0.
323 //
324 if (EFI_ERROR (Status)) {
325 SecureBootMode = SECURE_BOOT_MODE_DISABLE;
326 } else {
327 if (mPlatformMode == USER_MODE) {
328 SecureBootMode = SECURE_BOOT_MODE_ENABLE;
329 } else if (mPlatformMode == SETUP_MODE) {
330 SecureBootMode = SECURE_BOOT_MODE_DISABLE;
331 } else {
332 return EFI_NOT_FOUND;
333 }
334 }
335
336 Status = AuthServiceInternalUpdateVariable (
337 EFI_SECURE_BOOT_MODE_NAME,
338 &gEfiGlobalVariableGuid,
339 &SecureBootMode,
340 sizeof (UINT8),
341 EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS
342 );
343 if (EFI_ERROR (Status)) {
344 return Status;
345 }
346
347 //
348 // Check "SecureBootEnable" variable's existence. It can enable/disable secure boot feature.
349 //
350 Status = AuthServiceInternalFindVariable (
351 EFI_SECURE_BOOT_ENABLE_NAME,
352 &gEfiSecureBootEnableDisableGuid,
353 &Data,
354 &DataSize
355 );
356
357 if (SecureBootMode == SECURE_BOOT_MODE_ENABLE) {
358 //
359 // Create the "SecureBootEnable" variable as secure boot is enabled.
360 //
361 SecureBootEnable = SECURE_BOOT_ENABLE;
362 VariableDataSize = sizeof (SecureBootEnable);
363 } else {
364 //
365 // Delete the "SecureBootEnable" variable if this variable exist as "SecureBoot"
366 // variable is not in secure boot state.
367 //
368 if (EFI_ERROR (Status)) {
369 return EFI_SUCCESS;
370 }
371
372 SecureBootEnable = SECURE_BOOT_DISABLE;
373 VariableDataSize = 0;
374 }
375
376 Status = AuthServiceInternalUpdateVariable (
377 EFI_SECURE_BOOT_ENABLE_NAME,
378 &gEfiSecureBootEnableDisableGuid,
379 &SecureBootEnable,
380 VariableDataSize,
381 EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS
382 );
383 return Status;
384 }
385
386 /**
387 Check input data form to make sure it is a valid EFI_SIGNATURE_LIST for PK/KEK/db/dbx/dbt variable.
388
389 @param[in] VariableName Name of Variable to be check.
390 @param[in] VendorGuid Variable vendor GUID.
391 @param[in] Data Point to the variable data to be checked.
392 @param[in] DataSize Size of Data.
393
394 @return EFI_INVALID_PARAMETER Invalid signature list format.
395 @return EFI_SUCCESS Passed signature list format check successfully.
396
397 **/
398 EFI_STATUS
399 CheckSignatureListFormat (
400 IN CHAR16 *VariableName,
401 IN EFI_GUID *VendorGuid,
402 IN VOID *Data,
403 IN UINTN DataSize
404 )
405 {
406 EFI_SIGNATURE_LIST *SigList;
407 UINTN SigDataSize;
408 UINT32 Index;
409 UINT32 SigCount;
410 BOOLEAN IsPk;
411 VOID *RsaContext;
412 EFI_SIGNATURE_DATA *CertData;
413 UINTN CertLen;
414
415 if (DataSize == 0) {
416 return EFI_SUCCESS;
417 }
418
419 ASSERT (VariableName != NULL && VendorGuid != NULL && Data != NULL);
420
421 if (CompareGuid (VendorGuid, &gEfiGlobalVariableGuid) && (StrCmp (VariableName, EFI_PLATFORM_KEY_NAME) == 0)) {
422 IsPk = TRUE;
423 } else if ((CompareGuid (VendorGuid, &gEfiGlobalVariableGuid) && (StrCmp (VariableName, EFI_KEY_EXCHANGE_KEY_NAME) == 0)) ||
424 (CompareGuid (VendorGuid, &gEfiImageSecurityDatabaseGuid) &&
425 ((StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE) == 0) || (StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE1) == 0) ||
426 (StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE2) == 0))))
427 {
428 IsPk = FALSE;
429 } else {
430 return EFI_SUCCESS;
431 }
432
433 SigCount = 0;
434 SigList = (EFI_SIGNATURE_LIST *)Data;
435 SigDataSize = DataSize;
436 RsaContext = NULL;
437
438 //
439 // Walk through the input signature list and check the data format.
440 // If any signature is incorrectly formed, the whole check will fail.
441 //
442 while ((SigDataSize > 0) && (SigDataSize >= SigList->SignatureListSize)) {
443 for (Index = 0; Index < (sizeof (mSupportSigItem) / sizeof (EFI_SIGNATURE_ITEM)); Index++ ) {
444 if (CompareGuid (&SigList->SignatureType, &mSupportSigItem[Index].SigType)) {
445 //
446 // The value of SignatureSize should always be 16 (size of SignatureOwner
447 // component) add the data length according to signature type.
448 //
449 if ((mSupportSigItem[Index].SigDataSize != ((UINT32) ~0)) &&
450 ((SigList->SignatureSize - sizeof (EFI_GUID)) != mSupportSigItem[Index].SigDataSize))
451 {
452 return EFI_INVALID_PARAMETER;
453 }
454
455 if ((mSupportSigItem[Index].SigHeaderSize != ((UINT32) ~0)) &&
456 (SigList->SignatureHeaderSize != mSupportSigItem[Index].SigHeaderSize))
457 {
458 return EFI_INVALID_PARAMETER;
459 }
460
461 break;
462 }
463 }
464
465 if (Index == (sizeof (mSupportSigItem) / sizeof (EFI_SIGNATURE_ITEM))) {
466 //
467 // Undefined signature type.
468 //
469 return EFI_INVALID_PARAMETER;
470 }
471
472 if (CompareGuid (&SigList->SignatureType, &gEfiCertX509Guid)) {
473 //
474 // Try to retrieve the RSA public key from the X.509 certificate.
475 // If this operation fails, it's not a valid certificate.
476 //
477 RsaContext = RsaNew ();
478 if (RsaContext == NULL) {
479 return EFI_INVALID_PARAMETER;
480 }
481
482 CertData = (EFI_SIGNATURE_DATA *)((UINT8 *)SigList + sizeof (EFI_SIGNATURE_LIST) + SigList->SignatureHeaderSize);
483 CertLen = SigList->SignatureSize - sizeof (EFI_GUID);
484 if (!RsaGetPublicKeyFromX509 (CertData->SignatureData, CertLen, &RsaContext)) {
485 RsaFree (RsaContext);
486 return EFI_INVALID_PARAMETER;
487 }
488
489 RsaFree (RsaContext);
490 }
491
492 if ((SigList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - SigList->SignatureHeaderSize) % SigList->SignatureSize != 0) {
493 return EFI_INVALID_PARAMETER;
494 }
495
496 SigCount += (SigList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - SigList->SignatureHeaderSize) / SigList->SignatureSize;
497
498 SigDataSize -= SigList->SignatureListSize;
499 SigList = (EFI_SIGNATURE_LIST *)((UINT8 *)SigList + SigList->SignatureListSize);
500 }
501
502 if (((UINTN)SigList - (UINTN)Data) != DataSize) {
503 return EFI_INVALID_PARAMETER;
504 }
505
506 if (IsPk && (SigCount > 1)) {
507 return EFI_INVALID_PARAMETER;
508 }
509
510 return EFI_SUCCESS;
511 }
512
513 /**
514 Update "VendorKeys" variable to record the out of band secure boot key modification.
515
516 @return EFI_SUCCESS Variable is updated successfully.
517 @return Others Failed to update variable.
518
519 **/
520 EFI_STATUS
521 VendorKeyIsModified (
522 VOID
523 )
524 {
525 EFI_STATUS Status;
526
527 if (mVendorKeyState == VENDOR_KEYS_MODIFIED) {
528 return EFI_SUCCESS;
529 }
530
531 mVendorKeyState = VENDOR_KEYS_MODIFIED;
532
533 Status = AuthServiceInternalUpdateVariable (
534 EFI_VENDOR_KEYS_NV_VARIABLE_NAME,
535 &gEfiVendorKeysNvGuid,
536 &mVendorKeyState,
537 sizeof (UINT8),
538 EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS
539 );
540 if (EFI_ERROR (Status)) {
541 return Status;
542 }
543
544 return AuthServiceInternalUpdateVariable (
545 EFI_VENDOR_KEYS_VARIABLE_NAME,
546 &gEfiGlobalVariableGuid,
547 &mVendorKeyState,
548 sizeof (UINT8),
549 EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS
550 );
551 }
552
553 /**
554 Process variable with platform key for verification.
555
556 Caution: This function may receive untrusted input.
557 This function may be invoked in SMM mode, and datasize and data are external input.
558 This function will do basic validation, before parse the data.
559 This function will parse the authentication carefully to avoid security issues, like
560 buffer overflow, integer overflow.
561 This function will check attribute carefully to avoid authentication bypass.
562
563 @param[in] VariableName Name of Variable to be found.
564 @param[in] VendorGuid Variable vendor GUID.
565 @param[in] Data Data pointer.
566 @param[in] DataSize Size of Data found. If size is less than the
567 data, this value contains the required size.
568 @param[in] Attributes Attribute value of the variable
569 @param[in] IsPk Indicate whether it is to process pk.
570
571 @return EFI_INVALID_PARAMETER Invalid parameter.
572 @return EFI_SECURITY_VIOLATION The variable does NOT pass the validation.
573 check carried out by the firmware.
574 @return EFI_SUCCESS Variable passed validation successfully.
575
576 **/
577 EFI_STATUS
578 ProcessVarWithPk (
579 IN CHAR16 *VariableName,
580 IN EFI_GUID *VendorGuid,
581 IN VOID *Data,
582 IN UINTN DataSize,
583 IN UINT32 Attributes OPTIONAL,
584 IN BOOLEAN IsPk
585 )
586 {
587 EFI_STATUS Status;
588 BOOLEAN Del;
589 UINT8 *Payload;
590 UINTN PayloadSize;
591
592 if (((Attributes & EFI_VARIABLE_NON_VOLATILE) == 0) ||
593 ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) == 0))
594 {
595 //
596 // PK, KEK and db/dbx/dbt should set EFI_VARIABLE_NON_VOLATILE attribute and should be a time-based
597 // authenticated variable.
598 //
599 return EFI_INVALID_PARAMETER;
600 }
601
602 //
603 // Init state of Del. State may change due to secure check
604 //
605 Del = FALSE;
606 if ( (InCustomMode () && UserPhysicalPresent ())
607 || ( (mPlatformMode == SETUP_MODE)
608 && !(FeaturePcdGet (PcdRequireSelfSignedPk) && IsPk)))
609 {
610 Payload = (UINT8 *)Data + AUTHINFO2_SIZE (Data);
611 PayloadSize = DataSize - AUTHINFO2_SIZE (Data);
612 if (PayloadSize == 0) {
613 Del = TRUE;
614 }
615
616 Status = CheckSignatureListFormat (VariableName, VendorGuid, Payload, PayloadSize);
617 if (EFI_ERROR (Status)) {
618 return Status;
619 }
620
621 Status = AuthServiceInternalUpdateVariableWithTimeStamp (
622 VariableName,
623 VendorGuid,
624 Payload,
625 PayloadSize,
626 Attributes,
627 &((EFI_VARIABLE_AUTHENTICATION_2 *)Data)->TimeStamp
628 );
629 if (EFI_ERROR (Status)) {
630 return Status;
631 }
632
633 if ( (mPlatformMode != SETUP_MODE)
634 || (FeaturePcdGet (PcdRequireSelfSignedPk) && IsPk))
635 {
636 Status = VendorKeyIsModified ();
637 }
638 } else if (mPlatformMode == USER_MODE) {
639 //
640 // Verify against X509 Cert in PK database.
641 //
642 Status = VerifyTimeBasedPayloadAndUpdate (
643 VariableName,
644 VendorGuid,
645 Data,
646 DataSize,
647 Attributes,
648 AuthVarTypePk,
649 &Del
650 );
651 } else {
652 //
653 // Verify against the certificate in data payload.
654 //
655 Status = VerifyTimeBasedPayloadAndUpdate (
656 VariableName,
657 VendorGuid,
658 Data,
659 DataSize,
660 Attributes,
661 AuthVarTypePayload,
662 &Del
663 );
664 }
665
666 if (!EFI_ERROR (Status) && IsPk) {
667 if ((mPlatformMode == SETUP_MODE) && !Del) {
668 //
669 // If enroll PK in setup mode, need change to user mode.
670 //
671 Status = UpdatePlatformMode (USER_MODE);
672 } else if ((mPlatformMode == USER_MODE) && Del) {
673 //
674 // If delete PK in user mode, need change to setup mode.
675 //
676 Status = UpdatePlatformMode (SETUP_MODE);
677 }
678 }
679
680 return Status;
681 }
682
683 /**
684 Process variable with key exchange key for verification.
685
686 Caution: This function may receive untrusted input.
687 This function may be invoked in SMM mode, and datasize and data are external input.
688 This function will do basic validation, before parse the data.
689 This function will parse the authentication carefully to avoid security issues, like
690 buffer overflow, integer overflow.
691 This function will check attribute carefully to avoid authentication bypass.
692
693 @param[in] VariableName Name of Variable to be found.
694 @param[in] VendorGuid Variable vendor GUID.
695 @param[in] Data Data pointer.
696 @param[in] DataSize Size of Data found. If size is less than the
697 data, this value contains the required size.
698 @param[in] Attributes Attribute value of the variable.
699
700 @return EFI_INVALID_PARAMETER Invalid parameter.
701 @return EFI_SECURITY_VIOLATION The variable does NOT pass the validation
702 check carried out by the firmware.
703 @return EFI_SUCCESS Variable pass validation successfully.
704
705 **/
706 EFI_STATUS
707 ProcessVarWithKek (
708 IN CHAR16 *VariableName,
709 IN EFI_GUID *VendorGuid,
710 IN VOID *Data,
711 IN UINTN DataSize,
712 IN UINT32 Attributes OPTIONAL
713 )
714 {
715 EFI_STATUS Status;
716 UINT8 *Payload;
717 UINTN PayloadSize;
718
719 if (((Attributes & EFI_VARIABLE_NON_VOLATILE) == 0) ||
720 ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) == 0))
721 {
722 //
723 // DB, DBX and DBT should set EFI_VARIABLE_NON_VOLATILE attribute and should be a time-based
724 // authenticated variable.
725 //
726 return EFI_INVALID_PARAMETER;
727 }
728
729 Status = EFI_SUCCESS;
730 if ((mPlatformMode == USER_MODE) && !(InCustomMode () && UserPhysicalPresent ())) {
731 //
732 // Time-based, verify against X509 Cert KEK.
733 //
734 return VerifyTimeBasedPayloadAndUpdate (
735 VariableName,
736 VendorGuid,
737 Data,
738 DataSize,
739 Attributes,
740 AuthVarTypeKek,
741 NULL
742 );
743 } else {
744 //
745 // If in setup mode or custom secure boot mode, no authentication needed.
746 //
747 Payload = (UINT8 *)Data + AUTHINFO2_SIZE (Data);
748 PayloadSize = DataSize - AUTHINFO2_SIZE (Data);
749
750 Status = CheckSignatureListFormat (VariableName, VendorGuid, Payload, PayloadSize);
751 if (EFI_ERROR (Status)) {
752 return Status;
753 }
754
755 Status = AuthServiceInternalUpdateVariableWithTimeStamp (
756 VariableName,
757 VendorGuid,
758 Payload,
759 PayloadSize,
760 Attributes,
761 &((EFI_VARIABLE_AUTHENTICATION_2 *)Data)->TimeStamp
762 );
763 if (EFI_ERROR (Status)) {
764 return Status;
765 }
766
767 if (mPlatformMode != SETUP_MODE) {
768 Status = VendorKeyIsModified ();
769 }
770 }
771
772 return Status;
773 }
774
775 /**
776 Check if it is to delete auth variable.
777
778 @param[in] OrgAttributes Original attribute value of the variable.
779 @param[in] Data Data pointer.
780 @param[in] DataSize Size of Data.
781 @param[in] Attributes Attribute value of the variable.
782
783 @retval TRUE It is to delete auth variable.
784 @retval FALSE It is not to delete auth variable.
785
786 **/
787 BOOLEAN
788 IsDeleteAuthVariable (
789 IN UINT32 OrgAttributes,
790 IN VOID *Data,
791 IN UINTN DataSize,
792 IN UINT32 Attributes
793 )
794 {
795 BOOLEAN Del;
796 UINTN PayloadSize;
797
798 Del = FALSE;
799
800 //
801 // To delete a variable created with the EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS
802 // or the EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS attribute,
803 // SetVariable must be used with attributes matching the existing variable
804 // and the DataSize set to the size of the AuthInfo descriptor.
805 //
806 if ((Attributes == OrgAttributes) &&
807 ((Attributes & (EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)) != 0))
808 {
809 if ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) {
810 PayloadSize = DataSize - AUTHINFO2_SIZE (Data);
811 if (PayloadSize == 0) {
812 Del = TRUE;
813 }
814 } else {
815 PayloadSize = DataSize - AUTHINFO_SIZE;
816 if (PayloadSize == 0) {
817 Del = TRUE;
818 }
819 }
820 }
821
822 return Del;
823 }
824
825 /**
826 Process variable with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set
827
828 Caution: This function may receive untrusted input.
829 This function may be invoked in SMM mode, and datasize and data are external input.
830 This function will do basic validation, before parse the data.
831 This function will parse the authentication carefully to avoid security issues, like
832 buffer overflow, integer overflow.
833 This function will check attribute carefully to avoid authentication bypass.
834
835 @param[in] VariableName Name of the variable.
836 @param[in] VendorGuid Variable vendor GUID.
837 @param[in] Data Data pointer.
838 @param[in] DataSize Size of Data.
839 @param[in] Attributes Attribute value of the variable.
840
841 @return EFI_INVALID_PARAMETER Invalid parameter.
842 @return EFI_WRITE_PROTECTED Variable is write-protected and needs authentication with
843 EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS or EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set.
844 @return EFI_OUT_OF_RESOURCES The Database to save the public key is full.
845 @return EFI_SECURITY_VIOLATION The variable is with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS
846 set, but the AuthInfo does NOT pass the validation
847 check carried out by the firmware.
848 @return EFI_SUCCESS Variable is not write-protected or pass validation successfully.
849
850 **/
851 EFI_STATUS
852 ProcessVariable (
853 IN CHAR16 *VariableName,
854 IN EFI_GUID *VendorGuid,
855 IN VOID *Data,
856 IN UINTN DataSize,
857 IN UINT32 Attributes
858 )
859 {
860 EFI_STATUS Status;
861 AUTH_VARIABLE_INFO OrgVariableInfo;
862
863 Status = EFI_SUCCESS;
864
865 ZeroMem (&OrgVariableInfo, sizeof (OrgVariableInfo));
866 Status = mAuthVarLibContextIn->FindVariable (
867 VariableName,
868 VendorGuid,
869 &OrgVariableInfo
870 );
871
872 // If the VariablePolicy engine is disabled, allow deletion of any authenticated variables.
873 if ((!EFI_ERROR (Status)) && IsDeleteAuthVariable (OrgVariableInfo.Attributes, Data, DataSize, Attributes) && (UserPhysicalPresent () || !IsVariablePolicyEnabled ())) {
874 //
875 // Allow the delete operation of common authenticated variable(AT or AW) at user physical presence.
876 //
877 Status = AuthServiceInternalUpdateVariable (
878 VariableName,
879 VendorGuid,
880 NULL,
881 0,
882 0
883 );
884 if (!EFI_ERROR (Status) && ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0)) {
885 Status = DeleteCertsFromDb (VariableName, VendorGuid, Attributes);
886 }
887
888 return Status;
889 }
890
891 if (NeedPhysicallyPresent (VariableName, VendorGuid) && !UserPhysicalPresent ()) {
892 //
893 // This variable is protected, only physical present user could modify its value.
894 //
895 return EFI_SECURITY_VIOLATION;
896 }
897
898 //
899 if ((Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) != 0) {
900 //
901 // Reject Counter Based Auth Variable processing request.
902 //
903 return EFI_UNSUPPORTED;
904 } else if ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) {
905 //
906 // Process Time-based Authenticated variable.
907 //
908 return VerifyTimeBasedPayloadAndUpdate (
909 VariableName,
910 VendorGuid,
911 Data,
912 DataSize,
913 Attributes,
914 AuthVarTypePriv,
915 NULL
916 );
917 }
918
919 if ((OrgVariableInfo.Data != NULL) &&
920 ((OrgVariableInfo.Attributes & (EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)) != 0))
921 {
922 //
923 // If the variable is already write-protected, it always needs authentication before update.
924 //
925 return EFI_WRITE_PROTECTED;
926 }
927
928 //
929 // Not authenticated variable, just update variable as usual.
930 //
931 Status = AuthServiceInternalUpdateVariable (VariableName, VendorGuid, Data, DataSize, Attributes);
932 return Status;
933 }
934
935 /**
936 Filter out the duplicated EFI_SIGNATURE_DATA from the new data by comparing to the original data.
937
938 @param[in] Data Pointer to original EFI_SIGNATURE_LIST.
939 @param[in] DataSize Size of Data buffer.
940 @param[in, out] NewData Pointer to new EFI_SIGNATURE_LIST.
941 @param[in, out] NewDataSize Size of NewData buffer.
942
943 **/
944 EFI_STATUS
945 FilterSignatureList (
946 IN VOID *Data,
947 IN UINTN DataSize,
948 IN OUT VOID *NewData,
949 IN OUT UINTN *NewDataSize
950 )
951 {
952 EFI_SIGNATURE_LIST *CertList;
953 EFI_SIGNATURE_DATA *Cert;
954 UINTN CertCount;
955 EFI_SIGNATURE_LIST *NewCertList;
956 EFI_SIGNATURE_DATA *NewCert;
957 UINTN NewCertCount;
958 UINTN Index;
959 UINTN Index2;
960 UINTN Size;
961 UINT8 *Tail;
962 UINTN CopiedCount;
963 UINTN SignatureListSize;
964 BOOLEAN IsNewCert;
965 UINT8 *TempData;
966 UINTN TempDataSize;
967 EFI_STATUS Status;
968
969 if (*NewDataSize == 0) {
970 return EFI_SUCCESS;
971 }
972
973 TempDataSize = *NewDataSize;
974 Status = mAuthVarLibContextIn->GetScratchBuffer (&TempDataSize, (VOID **)&TempData);
975 if (EFI_ERROR (Status)) {
976 return EFI_OUT_OF_RESOURCES;
977 }
978
979 Tail = TempData;
980
981 NewCertList = (EFI_SIGNATURE_LIST *)NewData;
982 while ((*NewDataSize > 0) && (*NewDataSize >= NewCertList->SignatureListSize)) {
983 NewCert = (EFI_SIGNATURE_DATA *)((UINT8 *)NewCertList + sizeof (EFI_SIGNATURE_LIST) + NewCertList->SignatureHeaderSize);
984 NewCertCount = (NewCertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - NewCertList->SignatureHeaderSize) / NewCertList->SignatureSize;
985
986 CopiedCount = 0;
987 for (Index = 0; Index < NewCertCount; Index++) {
988 IsNewCert = TRUE;
989
990 Size = DataSize;
991 CertList = (EFI_SIGNATURE_LIST *)Data;
992 while ((Size > 0) && (Size >= CertList->SignatureListSize)) {
993 if (CompareGuid (&CertList->SignatureType, &NewCertList->SignatureType) &&
994 (CertList->SignatureSize == NewCertList->SignatureSize))
995 {
996 Cert = (EFI_SIGNATURE_DATA *)((UINT8 *)CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
997 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
998 for (Index2 = 0; Index2 < CertCount; Index2++) {
999 //
1000 // Iterate each Signature Data in this Signature List.
1001 //
1002 if (CompareMem (NewCert, Cert, CertList->SignatureSize) == 0) {
1003 IsNewCert = FALSE;
1004 break;
1005 }
1006
1007 Cert = (EFI_SIGNATURE_DATA *)((UINT8 *)Cert + CertList->SignatureSize);
1008 }
1009 }
1010
1011 if (!IsNewCert) {
1012 break;
1013 }
1014
1015 Size -= CertList->SignatureListSize;
1016 CertList = (EFI_SIGNATURE_LIST *)((UINT8 *)CertList + CertList->SignatureListSize);
1017 }
1018
1019 if (IsNewCert) {
1020 //
1021 // New EFI_SIGNATURE_DATA, keep it.
1022 //
1023 if (CopiedCount == 0) {
1024 //
1025 // Copy EFI_SIGNATURE_LIST header for only once.
1026 //
1027 CopyMem (Tail, NewCertList, sizeof (EFI_SIGNATURE_LIST) + NewCertList->SignatureHeaderSize);
1028 Tail = Tail + sizeof (EFI_SIGNATURE_LIST) + NewCertList->SignatureHeaderSize;
1029 }
1030
1031 CopyMem (Tail, NewCert, NewCertList->SignatureSize);
1032 Tail += NewCertList->SignatureSize;
1033 CopiedCount++;
1034 }
1035
1036 NewCert = (EFI_SIGNATURE_DATA *)((UINT8 *)NewCert + NewCertList->SignatureSize);
1037 }
1038
1039 //
1040 // Update SignatureListSize in the kept EFI_SIGNATURE_LIST.
1041 //
1042 if (CopiedCount != 0) {
1043 SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + NewCertList->SignatureHeaderSize + (CopiedCount * NewCertList->SignatureSize);
1044 CertList = (EFI_SIGNATURE_LIST *)(Tail - SignatureListSize);
1045 CertList->SignatureListSize = (UINT32)SignatureListSize;
1046 }
1047
1048 *NewDataSize -= NewCertList->SignatureListSize;
1049 NewCertList = (EFI_SIGNATURE_LIST *)((UINT8 *)NewCertList + NewCertList->SignatureListSize);
1050 }
1051
1052 TempDataSize = (Tail - (UINT8 *)TempData);
1053
1054 CopyMem (NewData, TempData, TempDataSize);
1055 *NewDataSize = TempDataSize;
1056
1057 return EFI_SUCCESS;
1058 }
1059
1060 /**
1061 Compare two EFI_TIME data.
1062
1063
1064 @param FirstTime A pointer to the first EFI_TIME data.
1065 @param SecondTime A pointer to the second EFI_TIME data.
1066
1067 @retval TRUE The FirstTime is not later than the SecondTime.
1068 @retval FALSE The FirstTime is later than the SecondTime.
1069
1070 **/
1071 BOOLEAN
1072 AuthServiceInternalCompareTimeStamp (
1073 IN EFI_TIME *FirstTime,
1074 IN EFI_TIME *SecondTime
1075 )
1076 {
1077 if (FirstTime->Year != SecondTime->Year) {
1078 return (BOOLEAN)(FirstTime->Year < SecondTime->Year);
1079 } else if (FirstTime->Month != SecondTime->Month) {
1080 return (BOOLEAN)(FirstTime->Month < SecondTime->Month);
1081 } else if (FirstTime->Day != SecondTime->Day) {
1082 return (BOOLEAN)(FirstTime->Day < SecondTime->Day);
1083 } else if (FirstTime->Hour != SecondTime->Hour) {
1084 return (BOOLEAN)(FirstTime->Hour < SecondTime->Hour);
1085 } else if (FirstTime->Minute != SecondTime->Minute) {
1086 return (BOOLEAN)(FirstTime->Minute < SecondTime->Minute);
1087 }
1088
1089 return (BOOLEAN)(FirstTime->Second <= SecondTime->Second);
1090 }
1091
1092 /**
1093 Calculate SHA256 digest of SignerCert CommonName + ToplevelCert tbsCertificate
1094 SignerCert and ToplevelCert are inside the signer certificate chain.
1095
1096 @param[in] SignerCert A pointer to SignerCert data.
1097 @param[in] SignerCertSize Length of SignerCert data.
1098 @param[in] TopLevelCert A pointer to TopLevelCert data.
1099 @param[in] TopLevelCertSize Length of TopLevelCert data.
1100 @param[out] Sha256Digest Sha256 digest calculated.
1101
1102 @return EFI_ABORTED Digest process failed.
1103 @return EFI_SUCCESS SHA256 Digest is successfully calculated.
1104
1105 **/
1106 EFI_STATUS
1107 CalculatePrivAuthVarSignChainSHA256Digest (
1108 IN UINT8 *SignerCert,
1109 IN UINTN SignerCertSize,
1110 IN UINT8 *TopLevelCert,
1111 IN UINTN TopLevelCertSize,
1112 OUT UINT8 *Sha256Digest
1113 )
1114 {
1115 UINT8 *TbsCert;
1116 UINTN TbsCertSize;
1117 CHAR8 CertCommonName[128];
1118 UINTN CertCommonNameSize;
1119 BOOLEAN CryptoStatus;
1120 EFI_STATUS Status;
1121
1122 CertCommonNameSize = sizeof (CertCommonName);
1123
1124 //
1125 // Get SignerCert CommonName
1126 //
1127 Status = X509GetCommonName (SignerCert, SignerCertSize, CertCommonName, &CertCommonNameSize);
1128 if (EFI_ERROR (Status)) {
1129 DEBUG ((DEBUG_INFO, "%a Get SignerCert CommonName failed with status %x\n", __FUNCTION__, Status));
1130 return EFI_ABORTED;
1131 }
1132
1133 //
1134 // Get TopLevelCert tbsCertificate
1135 //
1136 if (!X509GetTBSCert (TopLevelCert, TopLevelCertSize, &TbsCert, &TbsCertSize)) {
1137 DEBUG ((DEBUG_INFO, "%a Get Top-level Cert tbsCertificate failed!\n", __FUNCTION__));
1138 return EFI_ABORTED;
1139 }
1140
1141 //
1142 // Digest SignerCert CN + TopLevelCert tbsCertificate
1143 //
1144 ZeroMem (Sha256Digest, SHA256_DIGEST_SIZE);
1145 CryptoStatus = Sha256Init (mHashCtx);
1146 if (!CryptoStatus) {
1147 return EFI_ABORTED;
1148 }
1149
1150 //
1151 // '\0' is forced in CertCommonName. No overflow issue
1152 //
1153 CryptoStatus = Sha256Update (
1154 mHashCtx,
1155 CertCommonName,
1156 AsciiStrLen (CertCommonName)
1157 );
1158 if (!CryptoStatus) {
1159 return EFI_ABORTED;
1160 }
1161
1162 CryptoStatus = Sha256Update (mHashCtx, TbsCert, TbsCertSize);
1163 if (!CryptoStatus) {
1164 return EFI_ABORTED;
1165 }
1166
1167 CryptoStatus = Sha256Final (mHashCtx, Sha256Digest);
1168 if (!CryptoStatus) {
1169 return EFI_ABORTED;
1170 }
1171
1172 return EFI_SUCCESS;
1173 }
1174
1175 /**
1176 Find matching signer's certificates for common authenticated variable
1177 by corresponding VariableName and VendorGuid from "certdb" or "certdbv".
1178
1179 The data format of "certdb" or "certdbv":
1180 //
1181 // UINT32 CertDbListSize;
1182 // /// AUTH_CERT_DB_DATA Certs1[];
1183 // /// AUTH_CERT_DB_DATA Certs2[];
1184 // /// ...
1185 // /// AUTH_CERT_DB_DATA Certsn[];
1186 //
1187
1188 @param[in] VariableName Name of authenticated Variable.
1189 @param[in] VendorGuid Vendor GUID of authenticated Variable.
1190 @param[in] Data Pointer to variable "certdb" or "certdbv".
1191 @param[in] DataSize Size of variable "certdb" or "certdbv".
1192 @param[out] CertOffset Offset of matching CertData, from starting of Data.
1193 @param[out] CertDataSize Length of CertData in bytes.
1194 @param[out] CertNodeOffset Offset of matching AUTH_CERT_DB_DATA , from
1195 starting of Data.
1196 @param[out] CertNodeSize Length of AUTH_CERT_DB_DATA in bytes.
1197
1198 @retval EFI_INVALID_PARAMETER Any input parameter is invalid.
1199 @retval EFI_NOT_FOUND Fail to find matching certs.
1200 @retval EFI_SUCCESS Find matching certs and output parameters.
1201
1202 **/
1203 EFI_STATUS
1204 FindCertsFromDb (
1205 IN CHAR16 *VariableName,
1206 IN EFI_GUID *VendorGuid,
1207 IN UINT8 *Data,
1208 IN UINTN DataSize,
1209 OUT UINT32 *CertOffset OPTIONAL,
1210 OUT UINT32 *CertDataSize OPTIONAL,
1211 OUT UINT32 *CertNodeOffset OPTIONAL,
1212 OUT UINT32 *CertNodeSize OPTIONAL
1213 )
1214 {
1215 UINT32 Offset;
1216 AUTH_CERT_DB_DATA *Ptr;
1217 UINT32 CertSize;
1218 UINT32 NameSize;
1219 UINT32 NodeSize;
1220 UINT32 CertDbListSize;
1221
1222 if ((VariableName == NULL) || (VendorGuid == NULL) || (Data == NULL)) {
1223 return EFI_INVALID_PARAMETER;
1224 }
1225
1226 //
1227 // Check whether DataSize matches recorded CertDbListSize.
1228 //
1229 if (DataSize < sizeof (UINT32)) {
1230 return EFI_INVALID_PARAMETER;
1231 }
1232
1233 CertDbListSize = ReadUnaligned32 ((UINT32 *)Data);
1234
1235 if (CertDbListSize != (UINT32)DataSize) {
1236 return EFI_INVALID_PARAMETER;
1237 }
1238
1239 Offset = sizeof (UINT32);
1240
1241 //
1242 // Get corresponding certificates by VendorGuid and VariableName.
1243 //
1244 while (Offset < (UINT32)DataSize) {
1245 Ptr = (AUTH_CERT_DB_DATA *)(Data + Offset);
1246 //
1247 // Check whether VendorGuid matches.
1248 //
1249 if (CompareGuid (&Ptr->VendorGuid, VendorGuid)) {
1250 NodeSize = ReadUnaligned32 (&Ptr->CertNodeSize);
1251 NameSize = ReadUnaligned32 (&Ptr->NameSize);
1252 CertSize = ReadUnaligned32 (&Ptr->CertDataSize);
1253
1254 if (NodeSize != sizeof (EFI_GUID) + sizeof (UINT32) * 3 + CertSize +
1255 sizeof (CHAR16) * NameSize)
1256 {
1257 return EFI_INVALID_PARAMETER;
1258 }
1259
1260 Offset = Offset + sizeof (EFI_GUID) + sizeof (UINT32) * 3;
1261 //
1262 // Check whether VariableName matches.
1263 //
1264 if ((NameSize == StrLen (VariableName)) &&
1265 (CompareMem (Data + Offset, VariableName, NameSize * sizeof (CHAR16)) == 0))
1266 {
1267 Offset = Offset + NameSize * sizeof (CHAR16);
1268
1269 if (CertOffset != NULL) {
1270 *CertOffset = Offset;
1271 }
1272
1273 if (CertDataSize != NULL) {
1274 *CertDataSize = CertSize;
1275 }
1276
1277 if (CertNodeOffset != NULL) {
1278 *CertNodeOffset = (UINT32)((UINT8 *)Ptr - Data);
1279 }
1280
1281 if (CertNodeSize != NULL) {
1282 *CertNodeSize = NodeSize;
1283 }
1284
1285 return EFI_SUCCESS;
1286 } else {
1287 Offset = Offset + NameSize * sizeof (CHAR16) + CertSize;
1288 }
1289 } else {
1290 NodeSize = ReadUnaligned32 (&Ptr->CertNodeSize);
1291 Offset = Offset + NodeSize;
1292 }
1293 }
1294
1295 return EFI_NOT_FOUND;
1296 }
1297
1298 /**
1299 Retrieve signer's certificates for common authenticated variable
1300 by corresponding VariableName and VendorGuid from "certdb"
1301 or "certdbv" according to authenticated variable attributes.
1302
1303 @param[in] VariableName Name of authenticated Variable.
1304 @param[in] VendorGuid Vendor GUID of authenticated Variable.
1305 @param[in] Attributes Attributes of authenticated variable.
1306 @param[out] CertData Pointer to signer's certificates.
1307 @param[out] CertDataSize Length of CertData in bytes.
1308
1309 @retval EFI_INVALID_PARAMETER Any input parameter is invalid.
1310 @retval EFI_NOT_FOUND Fail to find "certdb"/"certdbv" or matching certs.
1311 @retval EFI_SUCCESS Get signer's certificates successfully.
1312
1313 **/
1314 EFI_STATUS
1315 GetCertsFromDb (
1316 IN CHAR16 *VariableName,
1317 IN EFI_GUID *VendorGuid,
1318 IN UINT32 Attributes,
1319 OUT UINT8 **CertData,
1320 OUT UINT32 *CertDataSize
1321 )
1322 {
1323 EFI_STATUS Status;
1324 UINT8 *Data;
1325 UINTN DataSize;
1326 UINT32 CertOffset;
1327 CHAR16 *DbName;
1328
1329 if ((VariableName == NULL) || (VendorGuid == NULL) || (CertData == NULL) || (CertDataSize == NULL)) {
1330 return EFI_INVALID_PARAMETER;
1331 }
1332
1333 if ((Attributes & EFI_VARIABLE_NON_VOLATILE) != 0) {
1334 //
1335 // Get variable "certdb".
1336 //
1337 DbName = EFI_CERT_DB_NAME;
1338 } else {
1339 //
1340 // Get variable "certdbv".
1341 //
1342 DbName = EFI_CERT_DB_VOLATILE_NAME;
1343 }
1344
1345 //
1346 // Get variable "certdb" or "certdbv".
1347 //
1348 Status = AuthServiceInternalFindVariable (
1349 DbName,
1350 &gEfiCertDbGuid,
1351 (VOID **)&Data,
1352 &DataSize
1353 );
1354 if (EFI_ERROR (Status)) {
1355 return Status;
1356 }
1357
1358 if ((DataSize == 0) || (Data == NULL)) {
1359 ASSERT (FALSE);
1360 return EFI_NOT_FOUND;
1361 }
1362
1363 Status = FindCertsFromDb (
1364 VariableName,
1365 VendorGuid,
1366 Data,
1367 DataSize,
1368 &CertOffset,
1369 CertDataSize,
1370 NULL,
1371 NULL
1372 );
1373
1374 if (EFI_ERROR (Status)) {
1375 return Status;
1376 }
1377
1378 *CertData = Data + CertOffset;
1379 return EFI_SUCCESS;
1380 }
1381
1382 /**
1383 Delete matching signer's certificates when deleting common authenticated
1384 variable by corresponding VariableName and VendorGuid from "certdb" or
1385 "certdbv" according to authenticated variable attributes.
1386
1387 @param[in] VariableName Name of authenticated Variable.
1388 @param[in] VendorGuid Vendor GUID of authenticated Variable.
1389 @param[in] Attributes Attributes of authenticated variable.
1390
1391 @retval EFI_INVALID_PARAMETER Any input parameter is invalid.
1392 @retval EFI_NOT_FOUND Fail to find "certdb"/"certdbv" or matching certs.
1393 @retval EFI_OUT_OF_RESOURCES The operation is failed due to lack of resources.
1394 @retval EFI_SUCCESS The operation is completed successfully.
1395
1396 **/
1397 EFI_STATUS
1398 DeleteCertsFromDb (
1399 IN CHAR16 *VariableName,
1400 IN EFI_GUID *VendorGuid,
1401 IN UINT32 Attributes
1402 )
1403 {
1404 EFI_STATUS Status;
1405 UINT8 *Data;
1406 UINTN DataSize;
1407 UINT32 VarAttr;
1408 UINT32 CertNodeOffset;
1409 UINT32 CertNodeSize;
1410 UINT8 *NewCertDb;
1411 UINT32 NewCertDbSize;
1412 CHAR16 *DbName;
1413
1414 if ((VariableName == NULL) || (VendorGuid == NULL)) {
1415 return EFI_INVALID_PARAMETER;
1416 }
1417
1418 if ((Attributes & EFI_VARIABLE_NON_VOLATILE) != 0) {
1419 //
1420 // Get variable "certdb".
1421 //
1422 DbName = EFI_CERT_DB_NAME;
1423 VarAttr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
1424 } else {
1425 //
1426 // Get variable "certdbv".
1427 //
1428 DbName = EFI_CERT_DB_VOLATILE_NAME;
1429 VarAttr = EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
1430 }
1431
1432 Status = AuthServiceInternalFindVariable (
1433 DbName,
1434 &gEfiCertDbGuid,
1435 (VOID **)&Data,
1436 &DataSize
1437 );
1438
1439 if (EFI_ERROR (Status)) {
1440 return Status;
1441 }
1442
1443 if ((DataSize == 0) || (Data == NULL)) {
1444 ASSERT (FALSE);
1445 return EFI_NOT_FOUND;
1446 }
1447
1448 if (DataSize == sizeof (UINT32)) {
1449 //
1450 // There is no certs in "certdb" or "certdbv".
1451 //
1452 return EFI_SUCCESS;
1453 }
1454
1455 //
1456 // Get corresponding cert node from "certdb" or "certdbv".
1457 //
1458 Status = FindCertsFromDb (
1459 VariableName,
1460 VendorGuid,
1461 Data,
1462 DataSize,
1463 NULL,
1464 NULL,
1465 &CertNodeOffset,
1466 &CertNodeSize
1467 );
1468
1469 if (EFI_ERROR (Status)) {
1470 return Status;
1471 }
1472
1473 if (DataSize < (CertNodeOffset + CertNodeSize)) {
1474 return EFI_NOT_FOUND;
1475 }
1476
1477 //
1478 // Construct new data content of variable "certdb" or "certdbv".
1479 //
1480 NewCertDbSize = (UINT32)DataSize - CertNodeSize;
1481 NewCertDb = (UINT8 *)mCertDbStore;
1482
1483 //
1484 // Copy the DB entries before deleting node.
1485 //
1486 CopyMem (NewCertDb, Data, CertNodeOffset);
1487 //
1488 // Update CertDbListSize.
1489 //
1490 CopyMem (NewCertDb, &NewCertDbSize, sizeof (UINT32));
1491 //
1492 // Copy the DB entries after deleting node.
1493 //
1494 if (DataSize > (CertNodeOffset + CertNodeSize)) {
1495 CopyMem (
1496 NewCertDb + CertNodeOffset,
1497 Data + CertNodeOffset + CertNodeSize,
1498 DataSize - CertNodeOffset - CertNodeSize
1499 );
1500 }
1501
1502 //
1503 // Set "certdb" or "certdbv".
1504 //
1505 Status = AuthServiceInternalUpdateVariable (
1506 DbName,
1507 &gEfiCertDbGuid,
1508 NewCertDb,
1509 NewCertDbSize,
1510 VarAttr
1511 );
1512
1513 return Status;
1514 }
1515
1516 /**
1517 Insert signer's certificates for common authenticated variable with VariableName
1518 and VendorGuid in AUTH_CERT_DB_DATA to "certdb" or "certdbv" according to
1519 time based authenticated variable attributes. CertData is the SHA256 digest of
1520 SignerCert CommonName + TopLevelCert tbsCertificate.
1521
1522 @param[in] VariableName Name of authenticated Variable.
1523 @param[in] VendorGuid Vendor GUID of authenticated Variable.
1524 @param[in] Attributes Attributes of authenticated variable.
1525 @param[in] SignerCert Signer certificate data.
1526 @param[in] SignerCertSize Length of signer certificate.
1527 @param[in] TopLevelCert Top-level certificate data.
1528 @param[in] TopLevelCertSize Length of top-level certificate.
1529
1530 @retval EFI_INVALID_PARAMETER Any input parameter is invalid.
1531 @retval EFI_ACCESS_DENIED An AUTH_CERT_DB_DATA entry with same VariableName
1532 and VendorGuid already exists.
1533 @retval EFI_OUT_OF_RESOURCES The operation is failed due to lack of resources.
1534 @retval EFI_SUCCESS Insert an AUTH_CERT_DB_DATA entry to "certdb" or "certdbv"
1535
1536 **/
1537 EFI_STATUS
1538 InsertCertsToDb (
1539 IN CHAR16 *VariableName,
1540 IN EFI_GUID *VendorGuid,
1541 IN UINT32 Attributes,
1542 IN UINT8 *SignerCert,
1543 IN UINTN SignerCertSize,
1544 IN UINT8 *TopLevelCert,
1545 IN UINTN TopLevelCertSize
1546 )
1547 {
1548 EFI_STATUS Status;
1549 UINT8 *Data;
1550 UINTN DataSize;
1551 UINT32 VarAttr;
1552 UINT8 *NewCertDb;
1553 UINT32 NewCertDbSize;
1554 UINT32 CertNodeSize;
1555 UINT32 NameSize;
1556 UINT32 CertDataSize;
1557 AUTH_CERT_DB_DATA *Ptr;
1558 CHAR16 *DbName;
1559 UINT8 Sha256Digest[SHA256_DIGEST_SIZE];
1560
1561 if ((VariableName == NULL) || (VendorGuid == NULL) || (SignerCert == NULL) || (TopLevelCert == NULL)) {
1562 return EFI_INVALID_PARAMETER;
1563 }
1564
1565 if ((Attributes & EFI_VARIABLE_NON_VOLATILE) != 0) {
1566 //
1567 // Get variable "certdb".
1568 //
1569 DbName = EFI_CERT_DB_NAME;
1570 VarAttr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
1571 } else {
1572 //
1573 // Get variable "certdbv".
1574 //
1575 DbName = EFI_CERT_DB_VOLATILE_NAME;
1576 VarAttr = EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
1577 }
1578
1579 //
1580 // Get variable "certdb" or "certdbv".
1581 //
1582 Status = AuthServiceInternalFindVariable (
1583 DbName,
1584 &gEfiCertDbGuid,
1585 (VOID **)&Data,
1586 &DataSize
1587 );
1588 if (EFI_ERROR (Status)) {
1589 return Status;
1590 }
1591
1592 if ((DataSize == 0) || (Data == NULL)) {
1593 ASSERT (FALSE);
1594 return EFI_NOT_FOUND;
1595 }
1596
1597 //
1598 // Find whether matching cert node already exists in "certdb" or "certdbv".
1599 // If yes return error.
1600 //
1601 Status = FindCertsFromDb (
1602 VariableName,
1603 VendorGuid,
1604 Data,
1605 DataSize,
1606 NULL,
1607 NULL,
1608 NULL,
1609 NULL
1610 );
1611
1612 if (!EFI_ERROR (Status)) {
1613 ASSERT (FALSE);
1614 return EFI_ACCESS_DENIED;
1615 }
1616
1617 //
1618 // Construct new data content of variable "certdb" or "certdbv".
1619 //
1620 NameSize = (UINT32)StrLen (VariableName);
1621 CertDataSize = sizeof (Sha256Digest);
1622 CertNodeSize = sizeof (AUTH_CERT_DB_DATA) + (UINT32)CertDataSize + NameSize * sizeof (CHAR16);
1623 NewCertDbSize = (UINT32)DataSize + CertNodeSize;
1624 if (NewCertDbSize > mMaxCertDbSize) {
1625 return EFI_OUT_OF_RESOURCES;
1626 }
1627
1628 Status = CalculatePrivAuthVarSignChainSHA256Digest (
1629 SignerCert,
1630 SignerCertSize,
1631 TopLevelCert,
1632 TopLevelCertSize,
1633 Sha256Digest
1634 );
1635 if (EFI_ERROR (Status)) {
1636 return Status;
1637 }
1638
1639 NewCertDb = (UINT8 *)mCertDbStore;
1640
1641 //
1642 // Copy the DB entries before inserting node.
1643 //
1644 CopyMem (NewCertDb, Data, DataSize);
1645 //
1646 // Update CertDbListSize.
1647 //
1648 CopyMem (NewCertDb, &NewCertDbSize, sizeof (UINT32));
1649 //
1650 // Construct new cert node.
1651 //
1652 Ptr = (AUTH_CERT_DB_DATA *)(NewCertDb + DataSize);
1653 CopyGuid (&Ptr->VendorGuid, VendorGuid);
1654 CopyMem (&Ptr->CertNodeSize, &CertNodeSize, sizeof (UINT32));
1655 CopyMem (&Ptr->NameSize, &NameSize, sizeof (UINT32));
1656 CopyMem (&Ptr->CertDataSize, &CertDataSize, sizeof (UINT32));
1657
1658 CopyMem (
1659 (UINT8 *)Ptr + sizeof (AUTH_CERT_DB_DATA),
1660 VariableName,
1661 NameSize * sizeof (CHAR16)
1662 );
1663
1664 CopyMem (
1665 (UINT8 *)Ptr + sizeof (AUTH_CERT_DB_DATA) + NameSize * sizeof (CHAR16),
1666 Sha256Digest,
1667 CertDataSize
1668 );
1669
1670 //
1671 // Set "certdb" or "certdbv".
1672 //
1673 Status = AuthServiceInternalUpdateVariable (
1674 DbName,
1675 &gEfiCertDbGuid,
1676 NewCertDb,
1677 NewCertDbSize,
1678 VarAttr
1679 );
1680
1681 return Status;
1682 }
1683
1684 /**
1685 Clean up signer's certificates for common authenticated variable
1686 by corresponding VariableName and VendorGuid from "certdb".
1687 System may break down during Timebased Variable update & certdb update,
1688 make them inconsistent, this function is called in AuthVariable Init
1689 to ensure consistency.
1690
1691 @retval EFI_NOT_FOUND Fail to find variable "certdb".
1692 @retval EFI_OUT_OF_RESOURCES The operation is failed due to lack of resources.
1693 @retval EFI_SUCCESS The operation is completed successfully.
1694
1695 **/
1696 EFI_STATUS
1697 CleanCertsFromDb (
1698 VOID
1699 )
1700 {
1701 UINT32 Offset;
1702 AUTH_CERT_DB_DATA *Ptr;
1703 UINT32 NameSize;
1704 UINT32 NodeSize;
1705 CHAR16 *VariableName;
1706 EFI_STATUS Status;
1707 BOOLEAN CertCleaned;
1708 UINT8 *Data;
1709 UINTN DataSize;
1710 EFI_GUID AuthVarGuid;
1711 AUTH_VARIABLE_INFO AuthVariableInfo;
1712
1713 Status = EFI_SUCCESS;
1714
1715 //
1716 // Get corresponding certificates by VendorGuid and VariableName.
1717 //
1718 do {
1719 CertCleaned = FALSE;
1720
1721 //
1722 // Get latest variable "certdb"
1723 //
1724 Status = AuthServiceInternalFindVariable (
1725 EFI_CERT_DB_NAME,
1726 &gEfiCertDbGuid,
1727 (VOID **)&Data,
1728 &DataSize
1729 );
1730 if (EFI_ERROR (Status)) {
1731 return Status;
1732 }
1733
1734 if ((DataSize == 0) || (Data == NULL)) {
1735 ASSERT (FALSE);
1736 return EFI_NOT_FOUND;
1737 }
1738
1739 Offset = sizeof (UINT32);
1740
1741 while (Offset < (UINT32)DataSize) {
1742 Ptr = (AUTH_CERT_DB_DATA *)(Data + Offset);
1743 NodeSize = ReadUnaligned32 (&Ptr->CertNodeSize);
1744 NameSize = ReadUnaligned32 (&Ptr->NameSize);
1745
1746 //
1747 // Get VarName tailed with '\0'
1748 //
1749 VariableName = AllocateZeroPool ((NameSize + 1) * sizeof (CHAR16));
1750 if (VariableName == NULL) {
1751 return EFI_OUT_OF_RESOURCES;
1752 }
1753
1754 CopyMem (VariableName, (UINT8 *)Ptr + sizeof (AUTH_CERT_DB_DATA), NameSize * sizeof (CHAR16));
1755 //
1756 // Keep VarGuid aligned
1757 //
1758 CopyMem (&AuthVarGuid, &Ptr->VendorGuid, sizeof (EFI_GUID));
1759
1760 //
1761 // Find corresponding time auth variable
1762 //
1763 ZeroMem (&AuthVariableInfo, sizeof (AuthVariableInfo));
1764 Status = mAuthVarLibContextIn->FindVariable (
1765 VariableName,
1766 &AuthVarGuid,
1767 &AuthVariableInfo
1768 );
1769
1770 if (EFI_ERROR (Status) || ((AuthVariableInfo.Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) == 0)) {
1771 //
1772 // While cleaning certdb, always delete the variable in certdb regardless of it attributes.
1773 //
1774 Status = DeleteCertsFromDb (
1775 VariableName,
1776 &AuthVarGuid,
1777 AuthVariableInfo.Attributes | EFI_VARIABLE_NON_VOLATILE
1778 );
1779 CertCleaned = TRUE;
1780 DEBUG ((DEBUG_INFO, "Recovery!! Cert for Auth Variable %s Guid %g is removed for consistency\n", VariableName, &AuthVarGuid));
1781 FreePool (VariableName);
1782 break;
1783 }
1784
1785 FreePool (VariableName);
1786 Offset = Offset + NodeSize;
1787 }
1788 } while (CertCleaned);
1789
1790 return Status;
1791 }
1792
1793 /**
1794 Process variable with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set
1795
1796 Caution: This function may receive untrusted input.
1797 This function may be invoked in SMM mode, and datasize and data are external input.
1798 This function will do basic validation, before parse the data.
1799 This function will parse the authentication carefully to avoid security issues, like
1800 buffer overflow, integer overflow.
1801
1802 @param[in] VariableName Name of Variable to be found.
1803 @param[in] VendorGuid Variable vendor GUID.
1804 @param[in] Data Data pointer.
1805 @param[in] DataSize Size of Data found. If size is less than the
1806 data, this value contains the required size.
1807 @param[in] Attributes Attribute value of the variable.
1808 @param[in] AuthVarType Verify against PK, KEK database, private database or certificate in data payload.
1809 @param[in] OrgTimeStamp Pointer to original time stamp,
1810 original variable is not found if NULL.
1811 @param[out] VarPayloadPtr Pointer to variable payload address.
1812 @param[out] VarPayloadSize Pointer to variable payload size.
1813
1814 @retval EFI_INVALID_PARAMETER Invalid parameter.
1815 @retval EFI_SECURITY_VIOLATION The variable does NOT pass the validation
1816 check carried out by the firmware.
1817 @retval EFI_OUT_OF_RESOURCES Failed to process variable due to lack
1818 of resources.
1819 @retval EFI_SUCCESS Variable pass validation successfully.
1820
1821 **/
1822 EFI_STATUS
1823 VerifyTimeBasedPayload (
1824 IN CHAR16 *VariableName,
1825 IN EFI_GUID *VendorGuid,
1826 IN VOID *Data,
1827 IN UINTN DataSize,
1828 IN UINT32 Attributes,
1829 IN AUTHVAR_TYPE AuthVarType,
1830 IN EFI_TIME *OrgTimeStamp,
1831 OUT UINT8 **VarPayloadPtr,
1832 OUT UINTN *VarPayloadSize
1833 )
1834 {
1835 EFI_VARIABLE_AUTHENTICATION_2 *CertData;
1836 UINT8 *SigData;
1837 UINT32 SigDataSize;
1838 UINT8 *PayloadPtr;
1839 UINTN PayloadSize;
1840 UINT32 Attr;
1841 BOOLEAN VerifyStatus;
1842 EFI_STATUS Status;
1843 EFI_SIGNATURE_LIST *CertList;
1844 EFI_SIGNATURE_DATA *Cert;
1845 UINTN Index;
1846 UINTN CertCount;
1847 UINT32 KekDataSize;
1848 UINT8 *NewData;
1849 UINTN NewDataSize;
1850 UINT8 *Buffer;
1851 UINTN Length;
1852 UINT8 *TopLevelCert;
1853 UINTN TopLevelCertSize;
1854 UINT8 *TrustedCert;
1855 UINTN TrustedCertSize;
1856 UINT8 *SignerCerts;
1857 UINTN CertStackSize;
1858 UINT8 *CertsInCertDb;
1859 UINT32 CertsSizeinDb;
1860 UINT8 Sha256Digest[SHA256_DIGEST_SIZE];
1861 EFI_CERT_DATA *CertDataPtr;
1862
1863 //
1864 // 1. TopLevelCert is the top-level issuer certificate in signature Signer Cert Chain
1865 // 2. TrustedCert is the certificate which firmware trusts. It could be saved in protected
1866 // storage or PK payload on PK init
1867 //
1868 VerifyStatus = FALSE;
1869 CertData = NULL;
1870 NewData = NULL;
1871 Attr = Attributes;
1872 SignerCerts = NULL;
1873 TopLevelCert = NULL;
1874 CertsInCertDb = NULL;
1875 CertDataPtr = NULL;
1876
1877 //
1878 // When the attribute EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS is
1879 // set, then the Data buffer shall begin with an instance of a complete (and serialized)
1880 // EFI_VARIABLE_AUTHENTICATION_2 descriptor. The descriptor shall be followed by the new
1881 // variable value and DataSize shall reflect the combined size of the descriptor and the new
1882 // variable value. The authentication descriptor is not part of the variable data and is not
1883 // returned by subsequent calls to GetVariable().
1884 //
1885 CertData = (EFI_VARIABLE_AUTHENTICATION_2 *)Data;
1886
1887 //
1888 // Verify that Pad1, Nanosecond, TimeZone, Daylight and Pad2 components of the
1889 // TimeStamp value are set to zero.
1890 //
1891 if ((CertData->TimeStamp.Pad1 != 0) ||
1892 (CertData->TimeStamp.Nanosecond != 0) ||
1893 (CertData->TimeStamp.TimeZone != 0) ||
1894 (CertData->TimeStamp.Daylight != 0) ||
1895 (CertData->TimeStamp.Pad2 != 0))
1896 {
1897 return EFI_SECURITY_VIOLATION;
1898 }
1899
1900 if ((OrgTimeStamp != NULL) && ((Attributes & EFI_VARIABLE_APPEND_WRITE) == 0)) {
1901 if (AuthServiceInternalCompareTimeStamp (&CertData->TimeStamp, OrgTimeStamp)) {
1902 //
1903 // TimeStamp check fail, suspicious replay attack, return EFI_SECURITY_VIOLATION.
1904 //
1905 return EFI_SECURITY_VIOLATION;
1906 }
1907 }
1908
1909 //
1910 // wCertificateType should be WIN_CERT_TYPE_EFI_GUID.
1911 // Cert type should be EFI_CERT_TYPE_PKCS7_GUID.
1912 //
1913 if ((CertData->AuthInfo.Hdr.wCertificateType != WIN_CERT_TYPE_EFI_GUID) ||
1914 !CompareGuid (&CertData->AuthInfo.CertType, &gEfiCertPkcs7Guid))
1915 {
1916 //
1917 // Invalid AuthInfo type, return EFI_SECURITY_VIOLATION.
1918 //
1919 return EFI_SECURITY_VIOLATION;
1920 }
1921
1922 //
1923 // Find out Pkcs7 SignedData which follows the EFI_VARIABLE_AUTHENTICATION_2 descriptor.
1924 // AuthInfo.Hdr.dwLength is the length of the entire certificate, including the length of the header.
1925 //
1926 SigData = CertData->AuthInfo.CertData;
1927 SigDataSize = CertData->AuthInfo.Hdr.dwLength - (UINT32)(OFFSET_OF (WIN_CERTIFICATE_UEFI_GUID, CertData));
1928
1929 //
1930 // SignedData.digestAlgorithms shall contain the digest algorithm used when preparing the
1931 // signature. Only a digest algorithm of SHA-256 is accepted.
1932 //
1933 // According to PKCS#7 Definition (https://www.rfc-editor.org/rfc/rfc2315):
1934 // SignedData ::= SEQUENCE {
1935 // version Version,
1936 // digestAlgorithms DigestAlgorithmIdentifiers,
1937 // contentInfo ContentInfo,
1938 // .... }
1939 // The DigestAlgorithmIdentifiers can be used to determine the hash algorithm
1940 // in VARIABLE_AUTHENTICATION_2 descriptor.
1941 // This field has the fixed offset (+13) or (+32) based on whether the DER-encoded
1942 // ContentInfo structure is present or not, and can be calculated based on two
1943 // bytes of length encoding.
1944 //
1945 // Both condition can be handled in WrapPkcs7Data() in CryptPkcs7VerifyCommon.c.
1946 //
1947 // See below examples:
1948 //
1949 // 1. Without ContentInfo
1950 // 30 82 0c da // SEQUENCE (5 element) (3294 BYTES) -- SignedData
1951 // 02 01 01 // INTEGER 1 -- Version
1952 // 31 0f // SET (1 element) (15 BYTES) -- DigestAlgorithmIdentifiers
1953 // 30 0d // SEQUENCE (2 element) (13 BYTES) -- AlgorithmIdentifier
1954 // 06 09 // OBJECT-IDENTIFIER (9 BYTES) -- algorithm
1955 // 60 86 48 01 65 03 04 02 01 // sha256 [2.16.840.1.101.3.4.2.1]
1956 // 05 00 // NULL (0 BYTES) -- parameters
1957 //
1958 // Example from: https://uefi.org/revocationlistfile
1959 //
1960 // 2. With ContentInfo
1961 // 30 82 05 90 // SEQUENCE (1424 BYTES) -- ContentInfo
1962 // 06 09 // OBJECT-IDENTIFIER (9 BYTES) -- ContentType
1963 // 2a 86 48 86 f7 0d 01 07 02 // signedData [1.2.840.113549.1.7.2]
1964 // a0 82 05 81 // CONTEXT-SPECIFIC CONSTRUCTED TAG 0 (1409 BYTES) -- content
1965 // 30 82 05 7d // SEQUENCE (1405 BYTES) -- SignedData
1966 // 02 01 01 // INTEGER 1 -- Version
1967 // 31 0f // SET (1 element) (15 BYTES) -- DigestAlgorithmIdentifiers
1968 // 30 0d // SEQUENCE (13 BYTES) -- AlgorithmIdentifier
1969 // 06 09 // OBJECT-IDENTIFIER (9 BYTES) -- algorithm
1970 // 60 86 48 01 65 03 04 02 01 // sha256 [2.16.840.1.101.3.4.2.1]
1971 // 05 00 // NULL (0 BYTES) -- parameters
1972 //
1973 // Example generated with: https://wiki.archlinux.org/title/Unified_Extensible_Firmware_Interface/Secure_Boot#Manual_process
1974 //
1975 if ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) {
1976 if ( ( (SigDataSize >= (13 + sizeof (mSha256OidValue)))
1977 && ( ((*(SigData + 1) & TWO_BYTE_ENCODE) != TWO_BYTE_ENCODE)
1978 || (CompareMem (SigData + 13, &mSha256OidValue, sizeof (mSha256OidValue)) != 0)))
1979 && ( (SigDataSize >= (32 + sizeof (mSha256OidValue)))
1980 && ( ((*(SigData + 20) & TWO_BYTE_ENCODE) != TWO_BYTE_ENCODE)
1981 || (CompareMem (SigData + 32, &mSha256OidValue, sizeof (mSha256OidValue)) != 0))))
1982 {
1983 return EFI_SECURITY_VIOLATION;
1984 }
1985 }
1986
1987 //
1988 // Find out the new data payload which follows Pkcs7 SignedData directly.
1989 //
1990 PayloadPtr = SigData + SigDataSize;
1991 PayloadSize = DataSize - OFFSET_OF_AUTHINFO2_CERT_DATA - (UINTN)SigDataSize;
1992
1993 // If the VariablePolicy engine is disabled, allow deletion of any authenticated variables.
1994 if ((PayloadSize == 0) && ((Attributes & EFI_VARIABLE_APPEND_WRITE) == 0) && !IsVariablePolicyEnabled ()) {
1995 VerifyStatus = TRUE;
1996 goto Exit;
1997 }
1998
1999 //
2000 // Construct a serialization buffer of the values of the VariableName, VendorGuid and Attributes
2001 // parameters of the SetVariable() call and the TimeStamp component of the
2002 // EFI_VARIABLE_AUTHENTICATION_2 descriptor followed by the variable's new value
2003 // i.e. (VariableName, VendorGuid, Attributes, TimeStamp, Data)
2004 //
2005 NewDataSize = PayloadSize + sizeof (EFI_TIME) + sizeof (UINT32) +
2006 sizeof (EFI_GUID) + StrSize (VariableName) - sizeof (CHAR16);
2007
2008 //
2009 // Here is to reuse scratch data area(at the end of volatile variable store)
2010 // to reduce SMRAM consumption for SMM variable driver.
2011 // The scratch buffer is enough to hold the serialized data and safe to use,
2012 // because it is only used at here to do verification temporarily first
2013 // and then used in UpdateVariable() for a time based auth variable set.
2014 //
2015 Status = mAuthVarLibContextIn->GetScratchBuffer (&NewDataSize, (VOID **)&NewData);
2016 if (EFI_ERROR (Status)) {
2017 return EFI_OUT_OF_RESOURCES;
2018 }
2019
2020 Buffer = NewData;
2021 Length = StrLen (VariableName) * sizeof (CHAR16);
2022 CopyMem (Buffer, VariableName, Length);
2023 Buffer += Length;
2024
2025 Length = sizeof (EFI_GUID);
2026 CopyMem (Buffer, VendorGuid, Length);
2027 Buffer += Length;
2028
2029 Length = sizeof (UINT32);
2030 CopyMem (Buffer, &Attr, Length);
2031 Buffer += Length;
2032
2033 Length = sizeof (EFI_TIME);
2034 CopyMem (Buffer, &CertData->TimeStamp, Length);
2035 Buffer += Length;
2036
2037 CopyMem (Buffer, PayloadPtr, PayloadSize);
2038
2039 if (AuthVarType == AuthVarTypePk) {
2040 //
2041 // Verify that the signature has been made with the current Platform Key (no chaining for PK).
2042 // First, get signer's certificates from SignedData.
2043 //
2044 VerifyStatus = Pkcs7GetSigners (
2045 SigData,
2046 SigDataSize,
2047 &SignerCerts,
2048 &CertStackSize,
2049 &TopLevelCert,
2050 &TopLevelCertSize
2051 );
2052 if (!VerifyStatus) {
2053 goto Exit;
2054 }
2055
2056 //
2057 // Second, get the current platform key from variable. Check whether it's identical with signer's certificates
2058 // in SignedData. If not, return error immediately.
2059 //
2060 Status = AuthServiceInternalFindVariable (
2061 EFI_PLATFORM_KEY_NAME,
2062 &gEfiGlobalVariableGuid,
2063 &Data,
2064 &DataSize
2065 );
2066 if (EFI_ERROR (Status)) {
2067 VerifyStatus = FALSE;
2068 goto Exit;
2069 }
2070
2071 CertList = (EFI_SIGNATURE_LIST *)Data;
2072 Cert = (EFI_SIGNATURE_DATA *)((UINT8 *)CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
2073 if ((TopLevelCertSize != (CertList->SignatureSize - (sizeof (EFI_SIGNATURE_DATA) - 1))) ||
2074 (CompareMem (Cert->SignatureData, TopLevelCert, TopLevelCertSize) != 0))
2075 {
2076 VerifyStatus = FALSE;
2077 goto Exit;
2078 }
2079
2080 //
2081 // Verify Pkcs7 SignedData via Pkcs7Verify library.
2082 //
2083 VerifyStatus = Pkcs7Verify (
2084 SigData,
2085 SigDataSize,
2086 TopLevelCert,
2087 TopLevelCertSize,
2088 NewData,
2089 NewDataSize
2090 );
2091 } else if (AuthVarType == AuthVarTypeKek) {
2092 //
2093 // Get KEK database from variable.
2094 //
2095 Status = AuthServiceInternalFindVariable (
2096 EFI_KEY_EXCHANGE_KEY_NAME,
2097 &gEfiGlobalVariableGuid,
2098 &Data,
2099 &DataSize
2100 );
2101 if (EFI_ERROR (Status)) {
2102 return Status;
2103 }
2104
2105 //
2106 // Ready to verify Pkcs7 SignedData. Go through KEK Signature Database to find out X.509 CertList.
2107 //
2108 KekDataSize = (UINT32)DataSize;
2109 CertList = (EFI_SIGNATURE_LIST *)Data;
2110 while ((KekDataSize > 0) && (KekDataSize >= CertList->SignatureListSize)) {
2111 if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {
2112 Cert = (EFI_SIGNATURE_DATA *)((UINT8 *)CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
2113 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
2114 for (Index = 0; Index < CertCount; Index++) {
2115 //
2116 // Iterate each Signature Data Node within this CertList for a verify
2117 //
2118 TrustedCert = Cert->SignatureData;
2119 TrustedCertSize = CertList->SignatureSize - (sizeof (EFI_SIGNATURE_DATA) - 1);
2120
2121 //
2122 // Verify Pkcs7 SignedData via Pkcs7Verify library.
2123 //
2124 VerifyStatus = Pkcs7Verify (
2125 SigData,
2126 SigDataSize,
2127 TrustedCert,
2128 TrustedCertSize,
2129 NewData,
2130 NewDataSize
2131 );
2132 if (VerifyStatus) {
2133 goto Exit;
2134 }
2135
2136 Cert = (EFI_SIGNATURE_DATA *)((UINT8 *)Cert + CertList->SignatureSize);
2137 }
2138 }
2139
2140 KekDataSize -= CertList->SignatureListSize;
2141 CertList = (EFI_SIGNATURE_LIST *)((UINT8 *)CertList + CertList->SignatureListSize);
2142 }
2143 } else if (AuthVarType == AuthVarTypePriv) {
2144 //
2145 // Process common authenticated variable except PK/KEK/DB/DBX/DBT.
2146 // Get signer's certificates from SignedData.
2147 //
2148 VerifyStatus = Pkcs7GetSigners (
2149 SigData,
2150 SigDataSize,
2151 &SignerCerts,
2152 &CertStackSize,
2153 &TopLevelCert,
2154 &TopLevelCertSize
2155 );
2156 if (!VerifyStatus) {
2157 goto Exit;
2158 }
2159
2160 //
2161 // Get previously stored signer's certificates from certdb or certdbv for existing
2162 // variable. Check whether they are identical with signer's certificates
2163 // in SignedData. If not, return error immediately.
2164 //
2165 if (OrgTimeStamp != NULL) {
2166 VerifyStatus = FALSE;
2167
2168 Status = GetCertsFromDb (VariableName, VendorGuid, Attributes, &CertsInCertDb, &CertsSizeinDb);
2169 if (EFI_ERROR (Status)) {
2170 goto Exit;
2171 }
2172
2173 if (CertsSizeinDb == SHA256_DIGEST_SIZE) {
2174 //
2175 // Check hash of signer cert CommonName + Top-level issuer tbsCertificate against data in CertDb
2176 //
2177 CertDataPtr = (EFI_CERT_DATA *)(SignerCerts + 1);
2178 Status = CalculatePrivAuthVarSignChainSHA256Digest (
2179 CertDataPtr->CertDataBuffer,
2180 ReadUnaligned32 ((UINT32 *)&(CertDataPtr->CertDataLength)),
2181 TopLevelCert,
2182 TopLevelCertSize,
2183 Sha256Digest
2184 );
2185 if (EFI_ERROR (Status) || (CompareMem (Sha256Digest, CertsInCertDb, CertsSizeinDb) != 0)) {
2186 goto Exit;
2187 }
2188 } else {
2189 //
2190 // Keep backward compatible with previous solution which saves whole signer certs stack in CertDb
2191 //
2192 if ((CertStackSize != CertsSizeinDb) ||
2193 (CompareMem (SignerCerts, CertsInCertDb, CertsSizeinDb) != 0))
2194 {
2195 goto Exit;
2196 }
2197 }
2198 }
2199
2200 VerifyStatus = Pkcs7Verify (
2201 SigData,
2202 SigDataSize,
2203 TopLevelCert,
2204 TopLevelCertSize,
2205 NewData,
2206 NewDataSize
2207 );
2208 if (!VerifyStatus) {
2209 goto Exit;
2210 }
2211
2212 if ((OrgTimeStamp == NULL) && (PayloadSize != 0)) {
2213 //
2214 // When adding a new common authenticated variable, always save Hash of cn of signer cert + tbsCertificate of Top-level issuer
2215 //
2216 CertDataPtr = (EFI_CERT_DATA *)(SignerCerts + 1);
2217 Status = InsertCertsToDb (
2218 VariableName,
2219 VendorGuid,
2220 Attributes,
2221 CertDataPtr->CertDataBuffer,
2222 ReadUnaligned32 ((UINT32 *)&(CertDataPtr->CertDataLength)),
2223 TopLevelCert,
2224 TopLevelCertSize
2225 );
2226 if (EFI_ERROR (Status)) {
2227 VerifyStatus = FALSE;
2228 goto Exit;
2229 }
2230 }
2231 } else if (AuthVarType == AuthVarTypePayload) {
2232 CertList = (EFI_SIGNATURE_LIST *)PayloadPtr;
2233 Cert = (EFI_SIGNATURE_DATA *)((UINT8 *)CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
2234 TrustedCert = Cert->SignatureData;
2235 TrustedCertSize = CertList->SignatureSize - (sizeof (EFI_SIGNATURE_DATA) - 1);
2236 //
2237 // Verify Pkcs7 SignedData via Pkcs7Verify library.
2238 //
2239 VerifyStatus = Pkcs7Verify (
2240 SigData,
2241 SigDataSize,
2242 TrustedCert,
2243 TrustedCertSize,
2244 NewData,
2245 NewDataSize
2246 );
2247 } else {
2248 return EFI_SECURITY_VIOLATION;
2249 }
2250
2251 Exit:
2252
2253 if ((AuthVarType == AuthVarTypePk) || (AuthVarType == AuthVarTypePriv)) {
2254 if (TopLevelCert != NULL) {
2255 Pkcs7FreeSigners (TopLevelCert);
2256 }
2257
2258 if (SignerCerts != NULL) {
2259 Pkcs7FreeSigners (SignerCerts);
2260 }
2261 }
2262
2263 if (!VerifyStatus) {
2264 return EFI_SECURITY_VIOLATION;
2265 }
2266
2267 Status = CheckSignatureListFormat (VariableName, VendorGuid, PayloadPtr, PayloadSize);
2268 if (EFI_ERROR (Status)) {
2269 return Status;
2270 }
2271
2272 *VarPayloadPtr = PayloadPtr;
2273 *VarPayloadSize = PayloadSize;
2274
2275 return EFI_SUCCESS;
2276 }
2277
2278 /**
2279 Process variable with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set
2280
2281 Caution: This function may receive untrusted input.
2282 This function may be invoked in SMM mode, and datasize and data are external input.
2283 This function will do basic validation, before parse the data.
2284 This function will parse the authentication carefully to avoid security issues, like
2285 buffer overflow, integer overflow.
2286
2287 @param[in] VariableName Name of Variable to be found.
2288 @param[in] VendorGuid Variable vendor GUID.
2289 @param[in] Data Data pointer.
2290 @param[in] DataSize Size of Data found. If size is less than the
2291 data, this value contains the required size.
2292 @param[in] Attributes Attribute value of the variable.
2293 @param[in] AuthVarType Verify against PK, KEK database, private database or certificate in data payload.
2294 @param[out] VarDel Delete the variable or not.
2295
2296 @retval EFI_INVALID_PARAMETER Invalid parameter.
2297 @retval EFI_SECURITY_VIOLATION The variable does NOT pass the validation
2298 check carried out by the firmware.
2299 @retval EFI_OUT_OF_RESOURCES Failed to process variable due to lack
2300 of resources.
2301 @retval EFI_SUCCESS Variable pass validation successfully.
2302
2303 **/
2304 EFI_STATUS
2305 VerifyTimeBasedPayloadAndUpdate (
2306 IN CHAR16 *VariableName,
2307 IN EFI_GUID *VendorGuid,
2308 IN VOID *Data,
2309 IN UINTN DataSize,
2310 IN UINT32 Attributes,
2311 IN AUTHVAR_TYPE AuthVarType,
2312 OUT BOOLEAN *VarDel
2313 )
2314 {
2315 EFI_STATUS Status;
2316 EFI_STATUS FindStatus;
2317 UINT8 *PayloadPtr;
2318 UINTN PayloadSize;
2319 EFI_VARIABLE_AUTHENTICATION_2 *CertData;
2320 AUTH_VARIABLE_INFO OrgVariableInfo;
2321 BOOLEAN IsDel;
2322
2323 ZeroMem (&OrgVariableInfo, sizeof (OrgVariableInfo));
2324 FindStatus = mAuthVarLibContextIn->FindVariable (
2325 VariableName,
2326 VendorGuid,
2327 &OrgVariableInfo
2328 );
2329
2330 Status = VerifyTimeBasedPayload (
2331 VariableName,
2332 VendorGuid,
2333 Data,
2334 DataSize,
2335 Attributes,
2336 AuthVarType,
2337 (!EFI_ERROR (FindStatus)) ? OrgVariableInfo.TimeStamp : NULL,
2338 &PayloadPtr,
2339 &PayloadSize
2340 );
2341 if (EFI_ERROR (Status)) {
2342 return Status;
2343 }
2344
2345 if ( !EFI_ERROR (FindStatus)
2346 && (PayloadSize == 0)
2347 && ((Attributes & EFI_VARIABLE_APPEND_WRITE) == 0))
2348 {
2349 IsDel = TRUE;
2350 } else {
2351 IsDel = FALSE;
2352 }
2353
2354 CertData = (EFI_VARIABLE_AUTHENTICATION_2 *)Data;
2355
2356 //
2357 // Final step: Update/Append Variable if it pass Pkcs7Verify
2358 //
2359 Status = AuthServiceInternalUpdateVariableWithTimeStamp (
2360 VariableName,
2361 VendorGuid,
2362 PayloadPtr,
2363 PayloadSize,
2364 Attributes,
2365 &CertData->TimeStamp
2366 );
2367
2368 //
2369 // Delete signer's certificates when delete the common authenticated variable.
2370 //
2371 if (IsDel && (AuthVarType == AuthVarTypePriv) && !EFI_ERROR (Status)) {
2372 Status = DeleteCertsFromDb (VariableName, VendorGuid, Attributes);
2373 }
2374
2375 if (VarDel != NULL) {
2376 if (IsDel && !EFI_ERROR (Status)) {
2377 *VarDel = TRUE;
2378 } else {
2379 *VarDel = FALSE;
2380 }
2381 }
2382
2383 return Status;
2384 }
EFI Development Kit II mirror for PVE