Received-SPF: pass (google.com: domain of linux-crypto+bounces-2281-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Message-ID: <e641e2f1-16cf-4717-8a1f-8afac2644efe@citrix.com>
Date: Fri, 23 Feb 2024 18:20:27 +0000
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v8 06/15] x86: Add early SHA support for Secure Launch
 early measurements
Content-Language: en-GB
To: Eric Biggers <ebiggers@kernel.org>,
 Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Ard Biesheuvel <ardb@kernel.org>,
 Ross Philipson <ross.philipson@oracle.com>, linux-kernel@vger.kernel.org,
 x86@kernel.org, linux-integrity@vger.kernel.org, linux-doc@vger.kernel.org,
 linux-crypto@vger.kernel.org, kexec@lists.infradead.org,
 linux-efi@vger.kernel.org, dpsmith@apertussolutions.com, tglx@linutronix.de,
 mingo@redhat.com, bp@alien8.de, hpa@zytor.com, dave.hansen@linux.intel.com,
 mjg59@srcf.ucam.org, James.Bottomley@hansenpartnership.com,
 peterhuewe@gmx.de, jarkko@kernel.org, jgg@ziepe.ca, luto@amacapital.net,
 nivedita@alum.mit.edu, herbert@gondor.apana.org.au, davem@davemloft.net,
 kanth.ghatraju@oracle.com, trenchboot-devel@googlegroups.com
References: <20240214221847.2066632-1-ross.philipson@oracle.com>
 <20240214221847.2066632-7-ross.philipson@oracle.com>
 <CAMj1kXEmMBY_jc0uM5UgZbuZ3-C7NPKzg5AScaunyu9XzLgzZA@mail.gmail.com>
 <98ad92bb-ef17-4c15-88ba-252db2a2e738@citrix.com>
 <CAMj1kXFTu+bV2kQhAyu15hrYai20NcBLb4Zu8XG2Y-XjL0f+rw@mail.gmail.com>
 <1a8e69a7-89eb-4d36-94d6-0da662d8b72f@citrix.com>
 <CAMj1kXEvmGy9RJo4s8tECsFj2dufZ8jBPoJOEtkcGUoj+x2qsw@mail.gmail.com>
 <431a0b3a-47e5-4e61-a7fc-31cdf56f4e4c@citrix.com>
 <20240223175449.GA1112@sol.localdomain>
From: Andrew Cooper <andrew.cooper3@citrix.com>
Autocrypt: addr=andrew.cooper3@citrix.com; keydata=
 xsFNBFLhNn8BEADVhE+Hb8i0GV6mihnnr/uiQQdPF8kUoFzCOPXkf7jQ5sLYeJa0cQi6Penp
 VtiFYznTairnVsN5J+ujSTIb+OlMSJUWV4opS7WVNnxHbFTPYZVQ3erv7NKc2iVizCRZ2Kxn
 srM1oPXWRic8BIAdYOKOloF2300SL/bIpeD+x7h3w9B/qez7nOin5NzkxgFoaUeIal12pXSR
 Q354FKFoy6Vh96gc4VRqte3jw8mPuJQpfws+Pb+swvSf/i1q1+1I4jsRQQh2m6OTADHIqg2E
 ofTYAEh7R5HfPx0EXoEDMdRjOeKn8+vvkAwhviWXTHlG3R1QkbE5M/oywnZ83udJmi+lxjJ5
 YhQ5IzomvJ16H0Bq+TLyVLO/VRksp1VR9HxCzItLNCS8PdpYYz5TC204ViycobYU65WMpzWe
 LFAGn8jSS25XIpqv0Y9k87dLbctKKA14Ifw2kq5OIVu2FuX+3i446JOa2vpCI9GcjCzi3oHV
 e00bzYiHMIl0FICrNJU0Kjho8pdo0m2uxkn6SYEpogAy9pnatUlO+erL4LqFUO7GXSdBRbw5
 gNt25XTLdSFuZtMxkY3tq8MFss5QnjhehCVPEpE6y9ZjI4XB8ad1G4oBHVGK5LMsvg22PfMJ
 ISWFSHoF/B5+lHkCKWkFxZ0gZn33ju5n6/FOdEx4B8cMJt+cWwARAQABzSlBbmRyZXcgQ29v
 cGVyIDxhbmRyZXcuY29vcGVyM0BjaXRyaXguY29tPsLBegQTAQgAJAIbAwULCQgHAwUVCgkI
 CwUWAgMBAAIeAQIXgAUCWKD95wIZAQAKCRBlw/kGpdefoHbdD/9AIoR3k6fKl+RFiFpyAhvO
 59ttDFI7nIAnlYngev2XUR3acFElJATHSDO0ju+hqWqAb8kVijXLops0gOfqt3VPZq9cuHlh
 IMDquatGLzAadfFx2eQYIYT+FYuMoPZy/aTUazmJIDVxP7L383grjIkn+7tAv+qeDfE+txL4
 SAm1UHNvmdfgL2/lcmL3xRh7sub3nJilM93RWX1Pe5LBSDXO45uzCGEdst6uSlzYR/MEr+5Z
 JQQ32JV64zwvf/aKaagSQSQMYNX9JFgfZ3TKWC1KJQbX5ssoX/5hNLqxMcZV3TN7kU8I3kjK
 mPec9+1nECOjjJSO/h4P0sBZyIUGfguwzhEeGf4sMCuSEM4xjCnwiBwftR17sr0spYcOpqET
 ZGcAmyYcNjy6CYadNCnfR40vhhWuCfNCBzWnUW0lFoo12wb0YnzoOLjvfD6OL3JjIUJNOmJy
 RCsJ5IA/Iz33RhSVRmROu+TztwuThClw63g7+hoyewv7BemKyuU6FTVhjjW+XUWmS/FzknSi
 dAG+insr0746cTPpSkGl3KAXeWDGJzve7/SBBfyznWCMGaf8E2P1oOdIZRxHgWj0zNr1+ooF
 /PzgLPiCI4OMUttTlEKChgbUTQ+5o0P080JojqfXwbPAyumbaYcQNiH1/xYbJdOFSiBv9rpt
 TQTBLzDKXok86M7BTQRS4TZ/ARAAkgqudHsp+hd82UVkvgnlqZjzz2vyrYfz7bkPtXaGb9H4
 Rfo7mQsEQavEBdWWjbga6eMnDqtu+FC+qeTGYebToxEyp2lKDSoAsvt8w82tIlP/EbmRbDVn
 7bhjBlfRcFjVYw8uVDPptT0TV47vpoCVkTwcyb6OltJrvg/QzV9f07DJswuda1JH3/qvYu0p
 vjPnYvCq4NsqY2XSdAJ02HrdYPFtNyPEntu1n1KK+gJrstjtw7KsZ4ygXYrsm/oCBiVW/OgU
 g/XIlGErkrxe4vQvJyVwg6YH653YTX5hLLUEL1NS4TCo47RP+wi6y+TnuAL36UtK/uFyEuPy
 wwrDVcC4cIFhYSfsO0BumEI65yu7a8aHbGfq2lW251UcoU48Z27ZUUZd2Dr6O/n8poQHbaTd
 6bJJSjzGGHZVbRP9UQ3lkmkmc0+XCHmj5WhwNNYjgbbmML7y0fsJT5RgvefAIFfHBg7fTY/i
 kBEimoUsTEQz+N4hbKwo1hULfVxDJStE4sbPhjbsPCrlXf6W9CxSyQ0qmZ2bXsLQYRj2xqd1
 bpA+1o1j2N4/au1R/uSiUFjewJdT/LX1EklKDcQwpk06Af/N7VZtSfEJeRV04unbsKVXWZAk
 uAJyDDKN99ziC0Wz5kcPyVD1HNf8bgaqGDzrv3TfYjwqayRFcMf7xJaL9xXedMcAEQEAAcLB
 XwQYAQgACQUCUuE2fwIbDAAKCRBlw/kGpdefoG4XEACD1Qf/er8EA7g23HMxYWd3FXHThrVQ
 HgiGdk5Yh632vjOm9L4sd/GCEACVQKjsu98e8o3ysitFlznEns5EAAXEbITrgKWXDDUWGYxd
 pnjj2u+GkVdsOAGk0kxczX6s+VRBhpbBI2PWnOsRJgU2n10PZ3mZD4Xu9kU2IXYmuW+e5KCA
 vTArRUdCrAtIa1k01sPipPPw6dfxx2e5asy21YOytzxuWFfJTGnVxZZSCyLUO83sh6OZhJkk
 b9rxL9wPmpN/t2IPaEKoAc0FTQZS36wAMOXkBh24PQ9gaLJvfPKpNzGD8XWR5HHF0NLIJhgg
 4ZlEXQ2fVp3XrtocHqhu4UZR4koCijgB8sB7Tb0GCpwK+C4UePdFLfhKyRdSXuvY3AHJd4CP
 4JzW0Bzq/WXY3XMOzUTYApGQpnUpdOmuQSfpV9MQO+/jo7r6yPbxT7CwRS5dcQPzUiuHLK9i
 nvjREdh84qycnx0/6dDroYhp0DFv4udxuAvt1h4wGwTPRQZerSm4xaYegEFusyhbZrI0U9tJ
 B8WrhBLXDiYlyJT6zOV2yZFuW47VrLsjYnHwn27hmxTC/7tvG3euCklmkn9Sl9IAKFu29RSo
 d5bD8kMSCYsTqtTfT6W4A3qHGvIDta3ptLYpIAOD2sY3GYq2nf3Bbzx81wZK14JdDDHUX2Rs
 6+ahAA==
In-Reply-To: <20240223175449.GA1112@sol.localdomain>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

On 23/02/2024 5:54 pm, Eric Biggers wrote:
> On Fri, Feb 23, 2024 at 04:42:11PM +0000, Andrew Cooper wrote:
>> Yes, and I agree.  We're not looking to try and force this in with
>> underhand tactics.
>>
>> But a blind "nack to any SHA-1" is similarly damaging in the opposite
>> direction.
>>
> Well, reviewers have said they'd prefer that SHA-1 not be included and given
> some thoughtful reasons for that.  But also they've given suggestions on how to
> make the SHA-1 support more palatable, such as splitting it into a separate
> patch and giving it a proper justification.
>
> All suggestions have been ignored.

The public record demonstrates otherwise.

But are you saying that you'd be happy if the commit message read
something more like:

---8<---
For better or worse, Secure Launch needs SHA-1 and SHA-256.

The choice of hashes used lie with the platform firmware, not with
software, and is often outside of the users control.

Even if we'd prefer to use SHA-256-only, if firmware elected to start us
with the SHA-1 and SHA-256 backs active, we still need SHA-1 to parse
the TPM event log thus far, and deliberately cap the SHA-1 PCRs in order
to safely use SHA-256 for everything else.
---

?

~Andrew