What’s with the Markdown file being added to the root directory? Is that a mistake or part of a different release process? Thanks! - Bret From: Wadhawan, Divneil R via groups.io Sent: Wednesday, December 9, 2020 10:33 AM To: devel@edk2.groups.io Cc: Yao, Jiewen; Jian J Wang; Min Xu; Kinney, Michael D Subject: [EXTERNAL] [edk2-devel] [Patch 2/2] SecurityPkg: Add support for SHA-384/SHA-512 digest algos o Existing implementation of Authenticated Variables only support SHA-256 digest algorithms in signing scheme. o This has been extended to support SHA-384 and SHA-512 algorithms Cc: Jiewen Yao Cc: Jian J Wang Cc: Min Xu Cc: Michael D Kinney Signed-off-by: Divneil Rai Wadhawan --- SecurityPkg/Library/AuthVariableLib/AuthService.c | 8 +++-- AuthVariableDigestUpdate.md | 41 +++++++++++++++++++++++ 2 files changed, 47 insertions(+), 2 deletions(-) create mode 100644 AuthVariableDigestUpdate.md diff --git a/SecurityPkg/Library/AuthVariableLib/AuthService.c b/SecurityPkg/Library/AuthVariableLib/AuthService.c index 4fb609504d..8f024c42a8 100644 --- a/SecurityPkg/Library/AuthVariableLib/AuthService.c +++ b/SecurityPkg/Library/AuthVariableLib/AuthService.c @@ -35,6 +35,8 @@ SPDX-License-Identifier: BSD-2-Clause-Patent CONST UINT8 mRsaE[] = { 0x01, 0x00, 0x01 }; CONST UINT8 mSha256OidValue[] = { 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01 }; +CONST UINT8 mSha384OidValue[] = { 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02 }; +CONST UINT8 mSha512OidValue[] = { 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03 }; // // Requirement for different signature type which have been defined in UEFI spec. @@ -1901,7 +1903,7 @@ VerifyTimeBasedPayload ( // // SignedData.digestAlgorithms shall contain the digest algorithm used when preparing the - // signature. Only a digest algorithm of SHA-256 is accepted. + // signature. Digest algorithm of SHA-256, SHA-384, SHA-512 are accepted. // // According to PKCS#7 Definition: // SignedData ::= SEQUENCE { @@ -1916,7 +1918,9 @@ VerifyTimeBasedPayload ( if ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) { if (SigDataSize >= (13 + sizeof (mSha256OidValue))) { if (((*(SigData + 1) & TWO_BYTE_ENCODE) != TWO_BYTE_ENCODE) || - (CompareMem (SigData + 13, &mSha256OidValue, sizeof (mSha256OidValue)) != 0)) { + ((CompareMem (SigData + 13, &mSha256OidValue, sizeof (mSha256OidValue)) != 0) && + (CompareMem (SigData + 13, &mSha384OidValue, sizeof (mSha384OidValue)) != 0) && + (CompareMem (SigData + 13, &mSha512OidValue, sizeof (mSha512OidValue)) != 0))) { return EFI_SECURITY_VIOLATION; } } diff --git a/AuthVariableDigestUpdate.md b/AuthVariableDigestUpdate.md new file mode 100644 index 0000000000..10992845a4 --- /dev/null +++ b/AuthVariableDigestUpdate.md @@ -0,0 +1,41 @@ +# Title: Digest Algorithm flexibility in Authenticated Variable signatures + +# Status: Draft + +# Document: UEFI Specification Version 2.8 + +# License + +SPDX-License-Identifier: CC-BY-4.0 + +# Submitter: [TianoCore Community](https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.tianocore.org%2F&data=04%7C01%7CBret.Barkelew%40microsoft.com%7C5b6eb98d1288493a5f7f08d89c70f78b%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637431356285650012%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=7mtSkIFgxu5iIg519YwkxjFfx6DeXOVJT67j58dHSK4%3D&reserved=0) + +# Summary of the change +EFI_VARIABLE_AUTHENTICATION_2 specifies the SignedData.digestAlgorithms to be always +SHA256. The implication is that the signing algorithm can use RSA keys greater than +2048 bits, but the digest algorithm remains SHA256. The proposed change is to allow +digest algorithm to be greater than SHA256. + +# Benefits of the change +This brings agility to the signing mechanism of Authenticated variables by allowing +it to sign a larger digest. + +# Impact of the change +There is no impact on the existing Authenticated variables. + +# Detailed description of the change [normative updates] + +Bold text indicates the proposed change + +8.2.2 Using the EFI_VARIABLE_AUTHENTICATION_2 descriptor +When the attribute EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS is set, then the Data buffer shall begin with an instance of a complete (and serialized) ... + +Construct a DER-encoded PKCS #7 version 1.5 SignedData (see [RFC2315]) with the signed content as follows: + +a. SignedData.version shall be set to 1 + +b. SignedData.digestAlgorithms shall contain the digest algorithm used when preparing the signature. Only a digest algorithm greater than or equal to SHA-256 is accepted. + + +# Special Instructions +NA -- 2.16.2.windows.1