Reviewed-by: Star Zeng <star.z...@intel.com>
-----Original Message-----
From: Zhang, Chao B [mailto:chao.b.zh...@intel.com]
Sent: Friday, July 10, 2015 1:38 PM
To: edk2-devel@lists.sourceforge.net
Cc: Zhang, Chao B
Subject: [edk2] [PATCH V2] SecurityPkg: Make time based AuthVariable update
atomic
System may break during time based AuthVariable update, causing certdb
inconsistent. 2 ways are used to ensure update atomic.
1. Delete cert in certdb after variable is deleted 2. Clean up certdb on
variable initialization
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Chao Zhang <chao.b.zh...@intel.com>
---
SecurityPkg/Library/AuthVariableLib/AuthService.c | 175 +++++++++++++++++----
.../Library/AuthVariableLib/AuthServiceInternal.h | 16 ++
.../Library/AuthVariableLib/AuthVariableLib.c | 9 ++
3 files changed, 170 insertions(+), 30 deletions(-)
diff --git a/SecurityPkg/Library/AuthVariableLib/AuthService.c
b/SecurityPkg/Library/AuthVariableLib/AuthService.c
index b3e8933..8805f54 100644
--- a/SecurityPkg/Library/AuthVariableLib/AuthService.c
+++ b/SecurityPkg/Library/AuthVariableLib/AuthService.c
@@ -1205,18 +1205,17 @@ ProcessVariable (
//
// Allow the delete operation of common authenticated variable at user
physical presence.
//
- if ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) !=
0) {
+ Status = AuthServiceInternalUpdateVariable (
+ VariableName,
+ VendorGuid,
+ NULL,
+ 0,
+ 0
+ );
+ if (!EFI_ERROR (Status) && ((Attributes &
+ EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0)) {
Status = DeleteCertsFromDb (VariableName, VendorGuid);
}
- if (!EFI_ERROR (Status)) {
- Status = AuthServiceInternalUpdateVariable (
- VariableName,
- VendorGuid,
- NULL,
- 0,
- 0
- );
- }
+
return Status;
}
@@ -1965,6 +1964,109 @@ InsertCertsToDb ( }
/**
+ Clean up signer's certificates for common authenticated variable by
+ corresponding VariableName and VendorGuid from "certdb".
+ Sytem may break down during Timebased Variable update & certdb
+ update, make them inconsistent, this function is called in
+ AuthVariable Init to ensure consistency
+
+ @retval EFI_NOT_FOUND Fail to find matching certs.
+ @retval EFI_SUCCESS Find matching certs and output parameters.
+
+**/
+EFI_STATUS
+CleanCertsFromDb (
+ VOID
+ ){
+ UINT32 Offset;
+ AUTH_CERT_DB_DATA *Ptr;
+ UINT32 NameSize;
+ UINT32 NodeSize;
+ CHAR16 *VariableName;
+ EFI_STATUS Status;
+ BOOLEAN CertCleaned;
+ UINT8 *Data;
+ UINTN DataSize;
+ UINT8 *AuthVarData;
+ UINTN AuthVarDataSize;
+ EFI_GUID AuthVarGuid;
+
+ Status = EFI_SUCCESS;
+
+ //
+ // Get corresponding certificates by VendorGuid and VariableName.
+ //
+ do {
+ CertCleaned = FALSE;
+
+ //
+ // Get latest variable "certdb"
+ //
+ Status = AuthServiceInternalFindVariable (
+ EFI_CERT_DB_NAME,
+ &gEfiCertDbGuid,
+ (VOID **) &Data,
+ &DataSize
+ );
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ if ((DataSize == 0) || (Data == NULL)) {
+ ASSERT (FALSE);
+ return EFI_NOT_FOUND;
+ }
+
+ Offset = sizeof (UINT32);
+
+ while (Offset < (UINT32) DataSize) {
+ Ptr = (AUTH_CERT_DB_DATA *) (Data + Offset);
+ //
+ // Check whether VendorGuid matches.
+ //
+ NodeSize = ReadUnaligned32 (&Ptr->CertNodeSize);
+ NameSize = ReadUnaligned32 (&Ptr->NameSize);
+
+ //
+ // Get VarName tailed with '\0'
+ //
+ VariableName = AllocateZeroPool((NameSize + 1) * sizeof(CHAR16));
+ if (VariableName == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+ CopyMem (VariableName, (UINT8 *) Ptr + sizeof (AUTH_CERT_DB_DATA),
NameSize * sizeof(CHAR16));
+ //
+ // Keep VarGuid aligned
+ //
+ CopyMem (&AuthVarGuid, &Ptr->VendorGuid, sizeof(EFI_GUID));
+
+ //
+ // Find corresponding time auth variable
+ //
+ Status = AuthServiceInternalFindVariable (
+ VariableName,
+ &AuthVarGuid,
+ (VOID **) &AuthVarData,
+ &AuthVarDataSize
+ );
+
+ if (EFI_ERROR(Status)) {
+ Status = DeleteCertsFromDb(VariableName, &AuthVarGuid);
+ CertCleaned = TRUE;
+ DEBUG((EFI_D_INFO, "Recovery!! Cert for Auth Variable %s Guid %g is
removed for consistency\n", VariableName, &AuthVarGuid));
+ FreePool(VariableName);
+ break;
+ }
+
+ FreePool(VariableName);
+ Offset = Offset + NodeSize;
+ }
+ } while (CertCleaned);
+
+ return Status;
+}
+
+/**
Process variable with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set
Caution: This function may receive untrusted input.
@@ -2285,16 +2387,7 @@ VerifyTimeBasedPayload (
goto Exit;
}
- //
- // Delete signer's certificates when delete the common authenticated
variable.
- //
- if ((PayloadSize == 0) && (OrgTimeStamp != NULL) && ((Attributes &
EFI_VARIABLE_APPEND_WRITE) == 0)) {
- Status = DeleteCertsFromDb (VariableName, VendorGuid);
- if (EFI_ERROR (Status)) {
- VerifyStatus = FALSE;
- goto Exit;
- }
- } else if ((OrgTimeStamp == NULL) && (PayloadSize != 0)) {
+ if ((OrgTimeStamp == NULL) && (PayloadSize != 0)) {
//
// Insert signer's certificates when adding a new common authenticated
variable.
//
@@ -2389,6 +2482,7 @@ VerifyTimeBasedPayloadAndUpdate (
UINTN PayloadSize;
EFI_VARIABLE_AUTHENTICATION_2 *CertData;
AUTH_VARIABLE_INFO OrgVariableInfo;
+ BOOLEAN IsDel;
ZeroMem (&OrgVariableInfo, sizeof (OrgVariableInfo));
FindStatus = mAuthVarLibContextIn->FindVariable ( @@ -2412,8 +2506,12 @@
VerifyTimeBasedPayloadAndUpdate (
return Status;
}
- if ((PayloadSize == 0) && (VarDel != NULL)) {
- *VarDel = TRUE;
+ if (!EFI_ERROR(FindStatus)
+ && (PayloadSize == 0)
+ && ((Attributes & EFI_VARIABLE_APPEND_WRITE) == 0)) {
+ IsDel = TRUE;
+ } else {
+ IsDel = FALSE;
}
CertData = (EFI_VARIABLE_AUTHENTICATION_2 *) Data; @@ -2421,12 +2519,29 @@
VerifyTimeBasedPayloadAndUpdate (
//
// Final step: Update/Append Variable if it pass Pkcs7Verify
//
- return AuthServiceInternalUpdateVariableWithTimeStamp (
- VariableName,
- VendorGuid,
- PayloadPtr,
- PayloadSize,
- Attributes,
- &CertData->TimeStamp
- );
+ Status = AuthServiceInternalUpdateVariableWithTimeStamp (
+ VariableName,
+ VendorGuid,
+ PayloadPtr,
+ PayloadSize,
+ Attributes,
+ &CertData->TimeStamp
+ );
+
+ //
+ // Delete signer's certificates when delete the common authenticated
variable.
+ //
+ if (IsDel && AuthVarType == AuthVarTypePriv && !EFI_ERROR(Status) ) {
+ Status = DeleteCertsFromDb (VariableName, VendorGuid); }
+
+ if (VarDel != NULL) {
+ if (IsDel && !EFI_ERROR(Status)) {
+ *VarDel = TRUE;
+ } else {
+ *VarDel = FALSE;
+ }
+ }
+
+ return Status;
}
diff --git a/SecurityPkg/Library/AuthVariableLib/AuthServiceInternal.h
b/SecurityPkg/Library/AuthVariableLib/AuthServiceInternal.h
index 08fff3f..add05c2 100644
--- a/SecurityPkg/Library/AuthVariableLib/AuthServiceInternal.h
+++ b/SecurityPkg/Library/AuthVariableLib/AuthServiceInternal.h
@@ -187,6 +187,22 @@ DeleteCertsFromDb (
);
/**
+ Clean up signer's certificates for common authenticated variable by
+ corresponding VariableName and VendorGuid from "certdb".
+ Sytem may break down during Timebased Variable update & certdb
+ update, make them inconsistent, this function is called in
+ AuthVariable Init to ensure consistency
+
+ @retval EFI_NOT_FOUND Fail to find matching certs.
+ @retval EFI_SUCCESS Find matching certs and output parameters.
+
+**/
+EFI_STATUS
+CleanCertsFromDb (
+ VOID
+ );
+
+/**
Filter out the duplicated EFI_SIGNATURE_DATA from the new data by comparing
to the original data.
@param[in] Data Pointer to original EFI_SIGNATURE_LIST.
diff --git a/SecurityPkg/Library/AuthVariableLib/AuthVariableLib.c
b/SecurityPkg/Library/AuthVariableLib/AuthVariableLib.c
index 0bb0918..02df309 100644
--- a/SecurityPkg/Library/AuthVariableLib/AuthVariableLib.c
+++ b/SecurityPkg/Library/AuthVariableLib/AuthVariableLib.c
@@ -352,6 +352,15 @@ AuthVariableLibInitialize (
if (EFI_ERROR (Status)) {
return Status;
}
+ } else {
+ //
+ // Clean up Certs to make certDB & Time based auth variable consistent
+ //
+ Status = CleanCertsFromDb();
+ if (EFI_ERROR (Status)) {
+ DEBUG ((EFI_D_INFO, "Clean up CertDB fail! Status %x\n", Status));
+ return Status;
+ }
}
//
--
1.9.5.msysgit.1
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