[edk2-devel] [PATCH V1 2/3] OvmfPkg/TdTcg2Dxe: Fix the mapping error between PCR index and MR index
Min Xu
min.m.xu at intel.com
Wed Dec 14 07:14:18 UTC 2022
From: Min M Xu <min.m.xu at intel.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4179
According to UEFI Spec 2.10 it is supposed to return the mapping from PCR
index to CC MR index:
//
// In the current version, we use the below mapping for TDX:
//
// TPM PCR Index | CC Measurement Register Index | TDX-measurement register
// -----------------------------------------------------------------------
// 0 | 0 | MRTD
// 1, 7 | 1 | RTMR[0]
// 2~6 | 2 | RTMR[1]
// 8~15 | 3 | RTMR[2]
In the current implementation TdMapPcrToMrIndex returns the index of RTMR,
not the MR index.
After fix the spec unconsistent, other related codes are updated
accordingly.
1) The index of event log uses the input MrIndex.
2) MrIndex is decreated by 1 before it is sent for RTMR extending.
Cc: Erdem Aktas <erdemaktas at google.com> [ruleof2]
Cc: James Bottomley <jejb at linux.ibm.com> [jejb]
Cc: Jiewen Yao <jiewen.yao at intel.com> [jyao1]
Cc: Tom Lendacky <thomas.lendacky at amd.com> [tlendacky]
Cc: Arti Gupta <ARGU at microsoft.com>
Reported-by: Arti Gupta <ARGU at microsoft.com>
Signed-off-by: Min Xu <min.m.xu at intel.com>
---
OvmfPkg/IntelTdx/TdTcg2Dxe/TdTcg2Dxe.c | 89 +++++++++++++++++---------
1 file changed, 60 insertions(+), 29 deletions(-)
diff --git a/OvmfPkg/IntelTdx/TdTcg2Dxe/TdTcg2Dxe.c b/OvmfPkg/IntelTdx/TdTcg2Dxe/TdTcg2Dxe.c
index a6b4f8e0aa6b..d19923b0c682 100644
--- a/OvmfPkg/IntelTdx/TdTcg2Dxe/TdTcg2Dxe.c
+++ b/OvmfPkg/IntelTdx/TdTcg2Dxe/TdTcg2Dxe.c
@@ -49,7 +49,11 @@
#define PERF_ID_CC_TCG2_DXE 0x3130
#define CC_EVENT_LOG_AREA_COUNT_MAX 1
-#define INVALID_RTMR_INDEX 4
+#define CC_MR_INDEX_0_MRTD 0
+#define CC_MR_INDEX_1_RTMR0 1
+#define CC_MR_INDEX_2_RTMR1 2
+#define CC_MR_INDEX_3_RTMR2 3
+#define CC_MR_INDEX_INVALID 4
typedef struct {
CHAR16 *VariableName;
@@ -240,7 +244,7 @@ EFI_HANDLE mImageHandle;
Notes: PE/COFF image is checked by BasePeCoffLib PeCoffLoaderGetImageInfo().
- @param[in] MrIndex RTMR index
+ @param[in] RtmrIndex RTMR index
@param[in] ImageAddress Start address of image buffer.
@param[in] ImageSize Image size
@param[out] DigestList Digest list of this image.
@@ -251,7 +255,7 @@ EFI_HANDLE mImageHandle;
**/
EFI_STATUS
MeasurePeImageAndExtend (
- IN UINT32 MrIndex,
+ IN UINT32 RtmrIndex,
IN EFI_PHYSICAL_ADDRESS ImageAddress,
IN UINTN ImageSize,
OUT TPML_DIGEST_VALUES *DigestList
@@ -925,10 +929,22 @@ TcgCommLogEvent (
}
/**
- RTMR[0] => PCR[1,7]
- RTMR[1] => PCR[2,3,4,5]
- RTMR[2] => PCR[8~15]
- RTMR[3] => NA
+ According to UEFI Spec 2.10 Section 38.4.1:
+ The following table shows the TPM PCR index mapping and CC event log measurement
+ register index interpretation for Intel TDX, where MRTD means Trust Domain Measurement
+ Register and RTMR means Runtime Measurement Register
+
+ // TPM PCR Index | CC Measurement Register Index | TDX-measurement register
+ // ------------------------------------------------------------------------
+ // 0 | 0 | MRTD
+ // 1, 7 | 1 | RTMR[0]
+ // 2~6 | 2 | RTMR[1]
+ // 8~15 | 3 | RTMR[2]
+
+ @param[in] PCRIndex Index of the TPM PCR
+
+ @retval UINT32 Index of the CC Event Log Measurement Register Index
+ @retval CC_MR_INDEX_INVALID Invalid MR Index
**/
UINT32
EFIAPI
@@ -938,18 +954,20 @@ MapPcrToMrIndex (
{
UINT32 MrIndex;
- if ((PCRIndex > 16) || (PCRIndex == 6) || (PCRIndex == 0)) {
+ if (PCRIndex > 15) {
ASSERT (FALSE);
- return INVALID_RTMR_INDEX;
+ return CC_MR_INDEX_INVALID;
}
MrIndex = 0;
- if ((PCRIndex == 1) || (PCRIndex == 7)) {
- MrIndex = 0;
- } else if ((PCRIndex > 1) && (PCRIndex < 6)) {
- MrIndex = 1;
- } else if ((PCRIndex > 7) && (PCRIndex < 16)) {
- MrIndex = 2;
+ if (PCRIndex == 0) {
+ MrIndex = CC_MR_INDEX_0_MRTD;
+ } else if ((PCRIndex == 1) || (PCRIndex == 7)) {
+ MrIndex = CC_MR_INDEX_1_RTMR0;
+ } else if ((PCRIndex >= 2) && (PCRIndex <= 6)) {
+ MrIndex = CC_MR_INDEX_2_RTMR1;
+ } else if ((PCRIndex >= 8) && (PCRIndex <= 15)) {
+ MrIndex = CC_MR_INDEX_3_RTMR2;
}
return MrIndex;
@@ -967,13 +985,9 @@ TdMapPcrToMrIndex (
return EFI_INVALID_PARAMETER;
}
- if ((PCRIndex > 16) || (PCRIndex == 0) || (PCRIndex == 6)) {
- return EFI_INVALID_PARAMETER;
- }
-
*MrIndex = MapPcrToMrIndex (PCRIndex);
- return *MrIndex == INVALID_RTMR_INDEX ? EFI_INVALID_PARAMETER : EFI_SUCCESS;
+ return *MrIndex == CC_MR_INDEX_INVALID ? EFI_INVALID_PARAMETER : EFI_SUCCESS;
}
/**
@@ -1197,12 +1211,7 @@ TdxDxeLogHashEvent (
LogFormat = EFI_CC_EVENT_LOG_FORMAT_TCG_2;
ZeroMem (&CcEvent, sizeof (CcEvent));
- //
- // The index of event log is designed as below:
- // 0 : MRTD
- // 1-4: RTMR[0-3]
- //
- CcEvent.MrIndex = NewEventHdr->MrIndex + 1;
+ CcEvent.MrIndex = NewEventHdr->MrIndex;
CcEvent.EventType = NewEventHdr->EventType;
DigestBuffer = (UINT8 *)&CcEvent.Digests;
EventSizePtr = CopyDigestListToBuffer (DigestBuffer, DigestList, HASH_ALG_SHA384);
@@ -1270,8 +1279,16 @@ TdxDxeHashLogExtendEvent (
return Status;
}
+ //
+ // According to UEFI Spec 2.10 Section 38.4.1 the mapping between MrIndex and Intel
+ // TDX Measurement Register is:
+ // MrIndex 0 <--> MRTD
+ // MrIndex 1-3 <--> RTMR[0-2]
+ // Only the RMTR registers can be extended in TDVF by HashAndExtend. So MrIndex will
+ // decreased by 1 before it is sent to HashAndExtend.
+ //
Status = HashAndExtend (
- NewEventHdr->MrIndex,
+ NewEventHdr->MrIndex - 1,
HashData,
(UINTN)HashDataLen,
&DigestList
@@ -1335,7 +1352,13 @@ TdHashLogExtendEvent (
return EFI_INVALID_PARAMETER;
}
- if (CcEvent->Header.MrIndex > 4) {
+ if (CcEvent->Header.MrIndex == CC_MR_INDEX_0_MRTD) {
+ DEBUG ((DEBUG_ERROR, "%a: MRTD cannot be extended in TDVF.\n", __FUNCTION__));
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (CcEvent->Header.MrIndex >= CC_MR_INDEX_INVALID) {
+ DEBUG ((DEBUG_ERROR, "%a: MrIndex is invalid. (%d)\n", __FUNCTION__, CcEvent->Header.MrIndex));
return EFI_INVALID_PARAMETER;
}
@@ -1343,8 +1366,16 @@ TdHashLogExtendEvent (
NewEventHdr.EventType = CcEvent->Header.EventType;
NewEventHdr.EventSize = CcEvent->Size - sizeof (UINT32) - CcEvent->Header.HeaderSize;
if ((Flags & EFI_CC_FLAG_PE_COFF_IMAGE) != 0) {
+ //
+ // According to UEFI Spec 2.10 Section 38.4.1 the mapping between MrIndex and Intel
+ // TDX Measurement Register is:
+ // MrIndex 0 <--> MRTD
+ // MrIndex 1-3 <--> RTMR[0-2]
+ // Only the RMTR registers can be extended in TDVF by HashAndExtend. So MrIndex will
+ // decreased by 1 before it is sent to MeasurePeImageAndExtend.
+ //
Status = MeasurePeImageAndExtend (
- NewEventHdr.MrIndex,
+ NewEventHdr.MrIndex - 1,
DataToHash,
(UINTN)DataToHashLen,
&DigestList
--
2.29.2.windows.2
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