Re: [edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule verification with secure boot keys
Thanks Michael. Below is the use case: - Device vendor provides devices with UEFI preinstalled; - Customer gets the device in non-secure-boot mode by default, and would like to enroll the secure boot keys themselves in some automatic way (such as using capsule). PcdFmpDevicePkcs7CertBufferXdr is not used for two reasons for this use case: 1. Simplicity. So vendor doesn't need to be involved in the key management, and customer could create and sign the capsule themselves. 2. Secure reasons. Once customer fully own the device and put it into secure-boot mode, even the capsule from the device vendor couldn't be applied without being signed by customer. (The hardcoded PcdFmpDevicePkcs7CertBufferXdr couldn't achieve this goal). Thanks, Liming > -Original Message- > From: Kinney, Michael D > Sent: Wednesday, July 1, 2020 1:43 PM > To: devel@edk2.groups.io; Liming Sun ; Jiang, Guomin > ; Xu, Wei6 > ; Gao, Liming ; Kinney, Michael D > > Cc: Sean Brogan > Subject: RE: [edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule verification > with secure boot keys > > Liming Sun, > > Can you explain why you cannot use PcdFmpDevicePkcs7CertBufferXdr > for your use case? I want to understand the use case to see if > that feature can be applied or if a minor enhancement to this > feature can work. > > Using the UEFI Secure Boot DB for anything other than authentication > of UEFI boot loaders is not recommended. > > Thanks, > > Mike > > > -----Original Message- > > From: devel@edk2.groups.io On > > Behalf Of Liming Sun > > Sent: Wednesday, July 1, 2020 9:27 AM > > To: Jiang, Guomin ; > > devel@edk2.groups.io; Xu, Wei6 ; Gao, > > Liming ; Kinney, Michael D > > > > Cc: Sean Brogan > > Subject: Re: [edk2-devel] [PATCH] FmpDevicePkg: Enhance > > capsule verification with secure boot keys > > > > >> But if your customer indeed want it, you can add it > > to your customization code. > > Thanks. Yes, this is a behavior customer expects. This > > change just tries to provide a handy way to enroll > > initial keys. > > So the initial keys could be carried in the capsule > > itself. > > It also has "PcdFmpDeviceAllowSecureBootKeys" disabled > > by default, so it behaves the same as before. > > > > We'll try to use customization code instead as > > suggested. > > > > Thanks, > > Liming > > > > > -Original Message- > > > From: Jiang, Guomin > > > Sent: Tuesday, June 30, 2020 8:56 PM > > > To: Liming Sun ; > > devel@edk2.groups.io; Xu, Wei6 ; Gao, > > Liming ; > > > Kinney, Michael D > > > Cc: Sean Brogan > > > Subject: RE: [edk2-devel] [PATCH] FmpDevicePkg: > > Enhance capsule verification with secure boot keys > > > > > > I want to ask your one question: are you sure that > > every mother board which deliver to customer will enable > > the secure boot mode? > > > > > > I just emphasize that I want to make sure that the > > device firmware come from the device vendor. > > > > > > Thanks for your effort, the patch is good, I just > > think it is not suitable for common solution. > > > > > > But if your customer indeed want it, you can add it to > > your customization code. > > > > > > Thanks > > > Guomin > > > > > > > -Original Message- > > > > From: Liming Sun > > > > Sent: Tuesday, June 30, 2020 8:47 PM > > > > To: devel@edk2.groups.io; Jiang, Guomin > > ; Xu, > > > > Wei6 ; Gao, Liming > > ; Kinney, > > > > Michael D > > > > Cc: Sean Brogan > > > > Subject: RE: [edk2-devel] [PATCH] FmpDevicePkg: > > Enhance capsule > > > > verification with secure boot keys > > > > > > > > Thanks Guomin. > > > > > > > > I still have one question. Let's assume we're the > > device vendor and we let > > > > customer to enroll their keys. Once the keys are > > enrolled, the device will be > > > > in secure boot mode. Are you saying that the end > > user could "have the ability > > > > to enroll their DB without too many effort" even > > after the secure boot has > > > > been enabled already? > > > > > > > > Please correct me if I misunderstood it. > > > > > > > > - Liming > > > > > > > > > -Original Message- > > > > > From: devel@edk2.groups.io > > On Behalf Of >
Re: [edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule verification with secure boot keys
>> But if your customer indeed want it, you can add it to your customization >> code. Thanks. Yes, this is a behavior customer expects. This change just tries to provide a handy way to enroll initial keys. So the initial keys could be carried in the capsule itself. It also has "PcdFmpDeviceAllowSecureBootKeys" disabled by default, so it behaves the same as before. We'll try to use customization code instead as suggested. Thanks, Liming > -Original Message- > From: Jiang, Guomin > Sent: Tuesday, June 30, 2020 8:56 PM > To: Liming Sun ; devel@edk2.groups.io; Xu, Wei6 > ; Gao, Liming ; > Kinney, Michael D > Cc: Sean Brogan > Subject: RE: [edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule verification > with secure boot keys > > I want to ask your one question: are you sure that every mother board which > deliver to customer will enable the secure boot mode? > > I just emphasize that I want to make sure that the device firmware come from > the device vendor. > > Thanks for your effort, the patch is good, I just think it is not suitable > for common solution. > > But if your customer indeed want it, you can add it to your customization > code. > > Thanks > Guomin > > > -Original Message- > > From: Liming Sun > > Sent: Tuesday, June 30, 2020 8:47 PM > > To: devel@edk2.groups.io; Jiang, Guomin ; Xu, > > Wei6 ; Gao, Liming ; Kinney, > > Michael D > > Cc: Sean Brogan > > Subject: RE: [edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule > > verification with secure boot keys > > > > Thanks Guomin. > > > > I still have one question. Let's assume we're the device vendor and we let > > customer to enroll their keys. Once the keys are enrolled, the device will > > be > > in secure boot mode. Are you saying that the end user could "have the > > ability > > to enroll their DB without too many effort" even after the secure boot has > > been enabled already? > > > > Please correct me if I misunderstood it. > > > > - Liming > > > > > -Original Message- > > > From: devel@edk2.groups.io On Behalf Of > > Guomin > > > Jiang via groups.io > > > Sent: Tuesday, June 30, 2020 3:33 AM > > > To: devel@edk2.groups.io; Liming Sun ; Xu, Wei6 > > > ; Gao, Liming ; Kinney, > > > Michael D > > > Cc: Sean Brogan > > > Subject: Re: [edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule > > > verification with secure boot keys > > > > > > Liming, > > > > > > The end user have the ability to enroll their DB without too many effort. > > > > > > And I think some end user also have the ability to get insecure firmware > > which not from the device vendor. > > > > > > I suggest that tell the device vendor that it is critical that set the > > PcdFmpDevicePkcs7CertBufferXdr rather than decrease the security. > > > > > > Best Regards > > > Guomin > > > > > > > -Original Message- > > > > From: devel@edk2.groups.io On Behalf Of > > > > Liming Sun > > > > Sent: Tuesday, June 30, 2020 11:33 AM > > > > To: Jiang, Guomin ; devel@edk2.groups.io; > > > > Xu, > > > > Wei6 ; Gao, Liming ; > > > > Kinney, Michael D > > > > Cc: Sean Brogan > > > > Subject: Re: [edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule > > > > verification with secure boot keys > > > > > > > > Thanks Guomin for the comments! > > > > > > > > Below is the main scenario for the proposed change: > > > > > > > > - Device Manufacturer provides the devices with UEFI preinstalled in > > > > non- secure state and no hard-coded keys ( > > PcdFmpDevicePkcs7CertBufferXdr). > > > > > > > > - Customer (not End-User) enrolls their own keys in trusted > > > > environment before delivering to End User. > > > > This capsule approach can be used for large deployment without > > > > involving any private keys. > > > > > > > > Yes, I do agree that once it's delivered to End User it won't be > > > > considered secure. > > > > > > > > Thanks, > > > > Liming > > > > > > > > > -Original Message- > > > > > From: Jiang, Guomin > > > > > Sent: Sunday, June 28, 2020 11:18 PM > > > > > To: devel@edk2.groups.io; Liming Sun ; Xu, Wei6 > > > >
Re: [edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule verification with secure boot keys
Thanks Guomin. I still have one question. Let's assume we're the device vendor and we let customer to enroll their keys. Once the keys are enrolled, the device will be in secure boot mode. Are you saying that the end user could "have the ability to enroll their DB without too many effort" even after the secure boot has been enabled already? Please correct me if I misunderstood it. - Liming > -Original Message- > From: devel@edk2.groups.io On Behalf Of Guomin Jiang > via groups.io > Sent: Tuesday, June 30, 2020 3:33 AM > To: devel@edk2.groups.io; Liming Sun ; Xu, Wei6 > ; Gao, Liming ; > Kinney, Michael D > Cc: Sean Brogan > Subject: Re: [edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule verification > with secure boot keys > > Liming, > > The end user have the ability to enroll their DB without too many effort. > > And I think some end user also have the ability to get insecure firmware > which not from the device vendor. > > I suggest that tell the device vendor that it is critical that set the > PcdFmpDevicePkcs7CertBufferXdr rather than decrease the security. > > Best Regards > Guomin > > > -Original Message- > > From: devel@edk2.groups.io On Behalf Of Liming > > Sun > > Sent: Tuesday, June 30, 2020 11:33 AM > > To: Jiang, Guomin ; devel@edk2.groups.io; Xu, > > Wei6 ; Gao, Liming ; Kinney, > > Michael D > > Cc: Sean Brogan > > Subject: Re: [edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule > > verification with secure boot keys > > > > Thanks Guomin for the comments! > > > > Below is the main scenario for the proposed change: > > > > - Device Manufacturer provides the devices with UEFI preinstalled in non- > > secure state and no hard-coded keys ( PcdFmpDevicePkcs7CertBufferXdr). > > > > - Customer (not End-User) enrolls their own keys in trusted environment > > before delivering to End User. > > This capsule approach can be used for large deployment without involving any > > private keys. > > > > Yes, I do agree that once it's delivered to End User it won't be considered > > secure. > > > > Thanks, > > Liming > > > > > -Original Message- > > > From: Jiang, Guomin > > > Sent: Sunday, June 28, 2020 11:18 PM > > > To: devel@edk2.groups.io; Liming Sun ; Xu, Wei6 > > > ; Gao, Liming ; Kinney, > > > Michael D > > > Cc: Sean Brogan > > > Subject: RE: [edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule > > > verification with secure boot keys > > > > > > I think it have some vulnerability, the case as below. > > > > > > 1. Untrusted End User enroll the new DB key -> sign the untrusted > > > device firmware -> flash the untrusted device firmware -> the system will > > become unsafe. > > > > > > I think the end user is untrusted and we need to make sure only few person > > can have the privilege. > > > > > > Best Regards > > > Guomin > > > > > > > -Original Message- > > > > From: devel@edk2.groups.io On Behalf Of > > > > Liming Sun > > > > Sent: Saturday, June 20, 2020 1:48 AM > > > > To: Xu, Wei6 ; Gao, Liming > > > > ; Kinney, Michael D > > > > > > > > Cc: Liming Sun ; devel@edk2.groups.io; Sean > > > > Brogan > > > > Subject: [edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule > > > > verification with secure boot keys > > > > > > > > This commit enhances the FmpDevicePkg package to optionally verify > > > > capsule with the secure boot keys when > > > > PcdFmpDevicePkcs7CertBufferXdr is not set and the new PCD variable > > > > PcdFmpDeviceAllowSecureBootKeys is configured. Below is the check > > logic: > > > > - Pass if verified with PK key, or PK key not set yet; > > > > - Deny if verified with the DBX keys; > > > > - Verified it against the DB keys; > > > > > > > > One purpose for this change is to auto-deploy the UEFI secure boot > > > > keys with UEFI capsule. Initially it's done in trusted environment. > > > > Once secure boot is enabled, the same keys will be used to verify > > > > the signed capsules as well for further updates. > > > > > > > > Signed-off-by: Liming Sun > > > > --- > > > > FmpDevicePkg/FmpDevicePkg.dec | 6 +++ > > > > FmpDevicePkg/FmpDxe/FmpDxe.c | 109 > > > >
[edk2-devel] [PATCH] FmpDevicePkg: Enhance capsule verification with secure boot keys
This commit enhances the FmpDevicePkg package to optionally verify
capsule with the secure boot keys when PcdFmpDevicePkcs7CertBufferXdr
is not set and the new PCD variable PcdFmpDeviceAllowSecureBootKeys
is configured. Below is the check logic:
- Pass if verified with PK key, or PK key not set yet;
- Deny if verified with the DBX keys;
- Verified it against the DB keys;
One purpose for this change is to auto-deploy the UEFI secure boot
keys with UEFI capsule. Initially it's done in trusted environment.
Once secure boot is enabled, the same keys will be used to verify
the signed capsules as well for further updates.
Signed-off-by: Liming Sun
---
FmpDevicePkg/FmpDevicePkg.dec | 6 +++
FmpDevicePkg/FmpDxe/FmpDxe.c | 109 --
FmpDevicePkg/FmpDxe/FmpDxe.h | 1 +
FmpDevicePkg/FmpDxe/FmpDxe.inf| 3 ++
FmpDevicePkg/FmpDxe/FmpDxeLib.inf | 1 +
5 files changed, 117 insertions(+), 3 deletions(-)
diff --git a/FmpDevicePkg/FmpDevicePkg.dec b/FmpDevicePkg/FmpDevicePkg.dec
index cab63f5..3aeb89c 100644
--- a/FmpDevicePkg/FmpDevicePkg.dec
+++ b/FmpDevicePkg/FmpDevicePkg.dec
@@ -126,6 +126,12 @@
# @Prompt Firmware Device Image Type ID
gFmpDevicePkgTokenSpaceGuid.PcdFmpDeviceImageTypeIdGuid|{0}|VOID*|0x4010
+ ## This option is used to verify the capsule using secure boot keys if the
+ # PcdFmpDevicePkcs7CertBufferXdr is not configured. In such case, the check
+ # will pass if secure boot hasn't been enabled yet.
+ # @A flag to tell whether to use secure boot keys when
PcdFmpDevicePkcs7CertBufferXdr is not set.
+
gFmpDevicePkgTokenSpaceGuid.PcdFmpDeviceAllowSecureBootKeys|0x0|UINT8|0x4012
+
[PcdsFixedAtBuild, PcdsPatchableInModule, PcdsDynamic, PcdsDynamicEx]
## One or more PKCS7 certificates used to verify a firmware device capsule
# update image. Encoded using the Variable-Length Opaque Data format of RFC
diff --git a/FmpDevicePkg/FmpDxe/FmpDxe.c b/FmpDevicePkg/FmpDxe/FmpDxe.c
index 5884177..6f82aee 100644
--- a/FmpDevicePkg/FmpDxe/FmpDxe.c
+++ b/FmpDevicePkg/FmpDxe/FmpDxe.c
@@ -682,6 +682,102 @@ GetAllHeaderSize (
return CalculatedSize;
}
+EFI_STATUS
+CheckTheImageWithSecureBootVariable (
+ IN CONST CHAR16*Name,
+ IN CONST EFI_GUID *Guid,
+ IN CONST VOID *Image,
+ IN UINTN ImageSize
+ )
+{
+ EFI_STATUS Status;
+ VOID*Data;
+ UINTN Length;
+ EFI_SIGNATURE_LIST *CertList;
+ EFI_SIGNATURE_DATA *CertData;
+ UINTN CertCount;
+ UINTN Index;
+
+ Status = GetVariable2 (Name, Guid, , );
+ if (EFI_ERROR (Status)) {
+return EFI_NOT_FOUND;
+ }
+
+ CertList = (EFI_SIGNATURE_LIST *) Data;
+ while ((Length > 0) && (Length >= CertList->SignatureListSize)) {
+if (CompareGuid (>SignatureType, )) {
+ CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList +
+sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
+ CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) -
+CertList->SignatureHeaderSize) / CertList->SignatureSize;
+
+ for (Index = 0; Index < CertCount; Index++) {
+Status = AuthenticateFmpImage (
+ (EFI_FIRMWARE_IMAGE_AUTHENTICATION *)Image,
+ ImageSize,
+ CertData->SignatureData,
+ CertList->SignatureSize - sizeof (EFI_GUID)
+ );
+if (!EFI_ERROR (Status))
+ goto Done;
+
+CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertData +
CertList->SignatureSize);
+ }
+}
+
+Length -= CertList->SignatureListSize;
+CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList +
CertList->SignatureListSize);
+ }
+
+Done:
+ FreePool (Data);
+ return Status;
+}
+
+EFI_STATUS
+CheckTheImageWithSecureBootKeys (
+ IN CONST VOID *Image,
+ IN UINTN ImageSize
+ )
+{
+ EFI_STATUS Status;
+
+ // PK check.
+ Status = CheckTheImageWithSecureBootVariable(
+ EFI_PLATFORM_KEY_NAME,
+ ,
+ Image,
+ ImageSize
+ );
+ if (!EFI_ERROR (Status) || Status == EFI_NOT_FOUND) {
+// Return SUCCESS if verified by PK key or PK key not configured.
+DEBUG ((DEBUG_INFO, "FmpDxe: Verified capsule with PK key.\n"));
+return EFI_SUCCESS;
+ }
+
+ // DBX check.
+ Status = CheckTheImageWithSecureBootVariable(
+ EFI_IMAGE_SECURITY_DATABASE1,
+ ,
+ Image,
+ ImageSize
+ );
+ if (!EFI_ERROR (Status)) {
+DEBUG ((DEBUG_INFO, "FmpDxe: Reject capsule with DBX key.\n"));
+return EFI_SECURITY_VIOLATION;
+ }
+
+ // DB check.
+ DEBUG ((DEBUG_INFO, "FmpDxe: Verify capsule with DB key.\n"));
+ Status = CheckTheImageWithSecureBootVariable(
+ EFI_IMAGE_SECURITY_DATABASE,
+ ,
+ Image,
+ ImageSize
+
