[edk2-devel] [PATCH v2 04/11] OvmfPkg: add library class BlobVerifierLib with null implementation
Dov Murik
dovmurik at linux.ibm.com
Mon Jul 19 19:23:39 UTC 2021
On 19/07/2021 18:50, Tom Lendacky wrote:
> On 7/6/21 3:54 AM, Dov Murik wrote:
>> BlobVerifierLib will be used to verify blobs fetching them from QEMU's
>> firmware config (fw_cfg) in platforms that enable such verification.
>>
>> The null implementation NullBlobVerifierLib treats all blobs as valid.
>>
>> Cc: Laszlo Ersek <lersek at redhat.com>
>> Cc: Ard Biesheuvel <ardb+tianocore at kernel.org>
>> Cc: Jordan Justen <jordan.l.justen at intel.com>
>> Cc: Ashish Kalra <ashish.kalra at amd.com>
>> Cc: Brijesh Singh <brijesh.singh at amd.com>
>> Cc: Erdem Aktas <erdemaktas at google.com>
>> Cc: James Bottomley <jejb at linux.ibm.com>
>> Cc: Jiewen Yao <jiewen.yao at intel.com>
>> Cc: Min Xu <min.m.xu at intel.com>
>> Cc: Tom Lendacky <thomas.lendacky at amd.com>
>> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3457
>> Signed-off-by: Dov Murik <dovmurik at linux.ibm.com>
>> ---
>> OvmfPkg/OvmfPkg.dec | 3 ++
>> OvmfPkg/Library/BlobVerifierLib/NullBlobVerifierLib.inf | 27 ++++++++++++++
>> OvmfPkg/Include/Library/BlobVerifierLib.h | 38 ++++++++++++++++++++
>> OvmfPkg/Library/BlobVerifierLib/NullBlobVerifier.c | 34 ++++++++++++++++++
>> 4 files changed, 102 insertions(+)
>>
>> diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
>> index 6ae733f6e39f..f82228d69cc2 100644
>> --- a/OvmfPkg/OvmfPkg.dec
>> +++ b/OvmfPkg/OvmfPkg.dec
>> @@ -23,6 +23,9 @@ [LibraryClasses]
>> ## @libraryclass Access bhyve's firmware control interface.
>> BhyveFwCtlLib|Include/Library/BhyveFwCtlLib.h
>>
>> + ## @libraryclass Verify blobs read from the VMM
>> + BlobVerifierLib|Include/Library/BlobVerifierLib.h
>> +
>> ## @libraryclass Loads and boots a Linux kernel image
>> #
>> LoadLinuxLib|Include/Library/LoadLinuxLib.h
>> diff --git a/OvmfPkg/Library/BlobVerifierLib/NullBlobVerifierLib.inf b/OvmfPkg/Library/BlobVerifierLib/NullBlobVerifierLib.inf
>> new file mode 100644
>> index 000000000000..c8942ad05d96
>> --- /dev/null
>> +++ b/OvmfPkg/Library/BlobVerifierLib/NullBlobVerifierLib.inf
>> @@ -0,0 +1,27 @@
>> +## @file
>> +#
>> +# Null implementation of the blob verifier library.
>> +#
>> +# Copyright (C) 2021, IBM Corp
>> +#
>> +# SPDX-License-Identifier: BSD-2-Clause-Patent
>> +#
>> +##
>> +
>> +[Defines]
>> + INF_VERSION = 0x00010005
>
> You can specify the INF_VERSION using x.y format now, and I believe the
> latest is 1.29.
Thanks, I'll change that.
>
>> + BASE_NAME = NullBlobVerifierLib
>
> Typically, the NULL libraries would be named BlobVerifierLibNull.
You're right; I'll rename.
>
>> + FILE_GUID = b1b5533e-e01a-43bb-9e54-414f00ca036e
>> + MODULE_TYPE = BASE
>> + VERSION_STRING = 1.0
>> + LIBRARY_CLASS = BlobVerifierLib
>> +
>> +[Sources]
>> + NullBlobVerifier.c
>> +
>> +[Packages]
>> + MdePkg/MdePkg.dec
>> + OvmfPkg/OvmfPkg.dec
>> +
>> +[LibraryClasses]
>> + DebugLib
>
> Is this library (and associated include below) needed?
Probably not; I'll remove.
>
>> diff --git a/OvmfPkg/Include/Library/BlobVerifierLib.h b/OvmfPkg/Include/Library/BlobVerifierLib.h
>> new file mode 100644
>> index 000000000000..667024766681
>> --- /dev/null
>> +++ b/OvmfPkg/Include/Library/BlobVerifierLib.h
>> @@ -0,0 +1,38 @@
>> +/** @file
>> +
>> + Blob verification library
>> +
>> + This library class allows verifiying whether blobs from external sources
>> + (such as QEMU's firmware config) are trusted.
>> +
>> + Copyright (C) 2021, IBM Corporation
>> +
>> + SPDX-License-Identifier: BSD-2-Clause-Patent
>> +**/
>> +
>> +#ifndef BLOB_VERIFIER_LIB_H__
>> +#define BLOB_VERIFIER_LIB_H__
>> +
>> +#include <Uefi/UefiBaseType.h>
>> +#include <Base.h>
>> +
>> +/**
>> + Verify blob from an external source.
>> +
>> + @param BlobName The name of the blob
>
> I believe this is supposed to be @param[in]
>
OK.
>> + @param Buf The data of the blob
>> + @param BufSize The size of the blob in bytes
>> +
>> + @retval EFI_SUCCESS The blob was verified successfully.
>> + @retval EFI_ACCESS_DENIED The blob could not be verified, and therefore
>> + should be considered non-secure.
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +VerifyBlob (
>> + IN CONST CHAR16 *BlobName,
>> + IN CONST VOID *Buf,
>> + UINT32 BufSize
>
> Missing "IN" here (same below for these).
>
You're right. I'll add it.
Thanks,
-Dov
> Thanks,
> Tom
>
>> + );
>> +
>> +#endif
>> diff --git a/OvmfPkg/Library/BlobVerifierLib/NullBlobVerifier.c b/OvmfPkg/Library/BlobVerifierLib/NullBlobVerifier.c
>> new file mode 100644
>> index 000000000000..7b31b6ec767d
>> --- /dev/null
>> +++ b/OvmfPkg/Library/BlobVerifierLib/NullBlobVerifier.c
>> @@ -0,0 +1,34 @@
>> +/** @file
>> +
>> + Null implementation of the blob verifier library.
>> +
>> + Copyright (C) 2021, IBM Corporation
>> +
>> + SPDX-License-Identifier: BSD-2-Clause-Patent
>> +**/
>> +
>> +#include <Library/BaseLib.h>
>> +#include <Library/DebugLib.h>
>> +#include <Library/BlobVerifierLib.h>
>> +
>> +/**
>> + Verify blob from an external source.
>> +
>> + @param BlobName The name of the blob
>> + @param Buf The data of the blob
>> + @param BufSize The size of the blob in bytes
>> +
>> + @retval EFI_SUCCESS The blob was verified successfully.
>> + @retval EFI_ACCESS_DENIED The blob could not be verified, and therefore
>> + should be considered non-secure.
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +VerifyBlob (
>> + IN CONST CHAR16 *BlobName,
>> + IN CONST VOID *Buf,
>> + UINT32 BufSize
>> + )
>> +{
>> + return EFI_SUCCESS;
>> +}
>>
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