Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH 0/6] Add Hygon SEV support
To:     Pascal Van Leeuwen <pvanleeuwen@insidesecure.com>,
        Hao Feng <fenghao@hygon.cn>,
        'Tom Lendacky ' <thomas.lendacky@amd.com>,
        'Gary Hook ' <gary.hook@amd.com>,
        'Herbert Xu ' <herbert@gondor.apana.org.au>,
        "' David S. Miller '" <davem@davemloft.net>,
        'Janakarajan Natarajan ' <Janakarajan.Natarajan@amd.com>,
        'Joerg Roedel ' <joro@8bytes.org>,
        =?UTF-8?B?JyBSYWRpbSBLcsSNbcOhxZkgJw==?= <rkrcmar@redhat.com>,
        'Thomas Gleixner ' <tglx@linutronix.de>,
        'Ingo Molnar ' <mingo@redhat.com>,
        'Borislav Petkov ' <bp@alien8.de>,
        "' H. Peter Anvin '" <hpa@zytor.com>
Cc:     'Zhaohui Du ' <duzhaohui@hygon.cn>,
        'Zhiwei Ying ' <yingzhiwei@hygon.cn>,
        'Wen Pu ' <puwen@hygon.cn>,
        "x86@kernel.org" <x86@kernel.org>,
        "linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <1555329868-17895-1-git-send-email-fenghao@hygon.cn>
 <3a1288ab-8e18-5421-05b4-4f4ef2fc531c@redhat.com>
 <AM6PR09MB35237F925CF4C82FBBA53862D22B0@AM6PR09MB3523.eurprd09.prod.outlook.com>
 <fda47663-9536-0d36-5a0e-c6da77e21209@redhat.com>
 <AM6PR09MB35234C86C0502E1FAAB3A305D2240@AM6PR09MB3523.eurprd09.prod.outlook.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Openpgp: preference=signencrypt
Autocrypt: addr=pbonzini@redhat.com; prefer-encrypt=mutual; keydata=
 mQHhBFRCcBIBDqDGsz4K0zZun3jh+U6Z9wNGLKQ0kSFyjN38gMqU1SfP+TUNQepFHb/Gc0E2
 CxXPkIBTvYY+ZPkoTh5xF9oS1jqI8iRLzouzF8yXs3QjQIZ2SfuCxSVwlV65jotcjD2FTN04
 hVopm9llFijNZpVIOGUTqzM4U55sdsCcZUluWM6x4HSOdw5F5Utxfp1wOjD/v92Lrax0hjiX
 DResHSt48q+8FrZzY+AUbkUS+Jm34qjswdrgsC5uxeVcLkBgWLmov2kMaMROT0YmFY6A3m1S
 P/kXmHDXxhe23gKb3dgwxUTpENDBGcfEzrzilWueOeUWiOcWuFOed/C3SyijBx3Av/lbCsHU
 Vx6pMycNTdzU1BuAroB+Y3mNEuW56Yd44jlInzG2UOwt9XjjdKkJZ1g0P9dwptwLEgTEd3Fo
 UdhAQyRXGYO8oROiuh+RZ1lXp6AQ4ZjoyH8WLfTLf5g1EKCTc4C1sy1vQSdzIRu3rBIjAvnC
 tGZADei1IExLqB3uzXKzZ1BZ+Z8hnt2og9hb7H0y8diYfEk2w3R7wEr+Ehk5NQsT2MPI2QBd
 wEv1/Aj1DgUHZAHzG1QN9S8wNWQ6K9DqHZTBnI1hUlkp22zCSHK/6FwUCuYp1zcAEQEAAbQj
 UGFvbG8gQm9uemluaSA8cGJvbnppbmlAcmVkaGF0LmNvbT6JAg0EEwECACMFAlRCcBICGwMH
 CwkIBwMCAQYVCAIJCgsEFgIDAQIeAQIXgAAKCRB+FRAMzTZpsbceDp9IIN6BIA0Ol7MoB15E
 11kRz/ewzryFY54tQlMnd4xxfH8MTQ/mm9I482YoSwPMdcWFAKnUX6Yo30tbLiNB8hzaHeRj
 jx12K+ptqYbg+cevgOtbLAlL9kNgLLcsGqC2829jBCUTVeMSZDrzS97ole/YEez2qFpPnTV0
 VrRWClWVfYh+JfzpXmgyhbkuwUxNFk421s4Ajp3d8nPPFUGgBG5HOxzkAm7xb1cjAuJ+oi/K
 CHfkuN+fLZl/u3E/fw7vvOESApLU5o0icVXeakfSz0LsygEnekDbxPnE5af/9FEkXJD5EoYG
 SEahaEtgNrR4qsyxyAGYgZlS70vkSSYJ+iT2rrwEiDlo31MzRo6Ba2FfHBSJ7lcYdPT7bbk9
 AO3hlNMhNdUhoQv7M5HsnqZ6unvSHOKmReNaS9egAGdRN0/GPDWr9wroyJ65ZNQsHl9nXBqE
 AukZNr5oJO5vxrYiAuuTSd6UI/xFkjtkzltG3mw5ao2bBpk/V/YuePrJsnPFHG7NhizrxttB
 nTuOSCMo45pfHQ+XYd5K1+Cv/NzZFNWscm5htJ0HznY+oOsZvHTyGz3v91pn51dkRYN0otqr
 bQ4tlFFuVjArBZcapSIe6NV8C4cEiSS5AQ0EVEJxcwEIAK+nUrsUz3aP2aBjIrX3a1+C+39R
 nctpNIPcJjFJ/8WafRiwcEuLjbvJ/4kyM6K7pWUIQftl1P8Woxwb5nqL7zEFHh5I+hKS3haO
 5pgco//V0tWBGMKinjqntpd4U4Dl299dMBZ4rRbPvmI8rr63sCENxTnHhTECyHdGFpqSzWzy
 97rH68uqMpxbUeggVwYkYihZNd8xt1+lf7GWYNEO/QV8ar/qbRPG6PEfiPPHQd/sldGYavmd
 //o6TQLSJsvJyJDt7KxulnNT8Q2X/OdEuVQsRT5glLaSAeVAABcLAEnNgmCIGkX7TnQF8a6w
 gHGrZIR9ZCoKvDxAr7RP6mPeS9sAEQEAAYkDEgQYAQIACQUCVEJxcwIbAgEpCRB+FRAMzTZp
 scBdIAQZAQIABgUCVEJxcwAKCRC/+9JfeMeug/SlCACl7QjRnwHo/VzENWD9G2VpUOd9eRnS
 DZGQmPo6Mp3Wy8vL7snGFBfRseT9BevXBSkxvtOnUUV2YbyLmolAODqUGzUI8ViF339poOYN
 i6Ffek0E19IMQ5+CilqJJ2d5ZvRfaq70LA/Ly9jmIwwX4auvXrWl99/2wCkqnWZI+PAepkcX
 JRD4KY2fsvRi64/aoQmcxTiyyR7q3/52Sqd4EdMfj0niYJV0Xb9nt8G57Dp9v3Ox5JeWZKXS
 krFqy1qyEIypIrqcMbtXM7LSmiQ8aJRM4ZHYbvgjChJKR4PsKNQZQlMWGUJO4nVFSkrixc9R
 Z49uIqQK3b3ENB1QkcdMg9cxsB0Onih8zR+Wp1uDZXnz1ekto+EivLQLqvTjCCwLxxJafwKI
 bqhQ+hGR9jF34EFur5eWt9jJGloEPVv0GgQflQaE+rRGe+3f5ZDgRe5Y/EJVNhBhKcafcbP8
 MzmLRh3UDnYDwaeguYmxuSlMdjFL96YfhRBXs8tUw6SO9jtCgBvoOIBDCxxAJjShY4KIvEpK
 b2hSNr8KxzelKKlSXMtB1bbHbQxiQcerAipYiChUHq1raFc3V0eOyCXK205rLtknJHhM5pfG
 6taABGAMvJgm/MrVILIxvBuERj1FRgcgoXtiBmLEJSb7akcrRlqe3MoPTntSTNvNzAJmfWhd
 SvP0G1WDLolqvX0OtKMppI91AWVu72f1kolJg43wbaKpRJg1GMkKEI3H+jrrlTBrNl/8e20m
 TElPRDKzPiowmXeZqFSS1A6Azv0TJoo9as+lWF+P4zCXt40+Zhh5hdHO38EV7vFAVG3iuay6
 7ToF8Uy7tgc3mdH98WQSmHcn/H5PFYk3xTP3KHB7b0FZPdFPQXBZb9+tJeZBi9gMqcjMch+Y
 R8dmTcQRQX14bm5nXlBF7VpSOPZMR392LY7wzAvRdhz7aeIUkdO7VelaspFk2nT7wOj1Y6uL
 nRxQlLkBDQRUQnHuAQgAx4dxXO6/Zun0eVYOnr5GRl76+2UrAAemVv9Yfn2PbDIbxXqLff7o
 yVJIkw4WdhQIIvvtu5zH24iYjmdfbg8iWpP7NqxUQRUZJEWbx2CRwkMHtOmzQiQ2tSLjKh/c
 HeyFH68xjeLcinR7jXMrHQK+UCEw6jqi1oeZzGvfmxarUmS0uRuffAb589AJW50kkQK9VD/9
 QC2FJISSUDnRC0PawGSZDXhmvITJMdD4TjYrePYhSY4uuIV02v028TVAaYbIhxvDY0hUQE4r
 8ZbGRLn52bEzaIPgl1p/adKfeOUeMReg/CkyzQpmyB1TSk8lDMxQzCYHXAzwnGi8WU9iuE1P
 0wARAQABiQHzBBgBAgAJBQJUQnHuAhsMAAoJEH4VEAzNNmmxp1EOoJy0uZggJm7gZKeJ7iUp
 eX4eqUtqelUw6gU2daz2hE/jsxsTbC/w5piHmk1H1VWDKEM4bQBTuiJ0bfo55SWsUNN+c9hh
 IX+Y8LEe22izK3w7mRpvGcg+/ZRG4DEMHLP6JVsv5GMpoYwYOmHnplOzCXHvmdlW0i6SrMsB
 Dl9rw4AtIa6bRwWLim1lQ6EM3PWifPrWSUPrPcw4OLSwFk0CPqC4HYv/7ZnASVkR5EERFF3+
 6iaaVi5OgBd81F1TCvCX2BEyIDRZLJNvX3TOd5FEN+lIrl26xecz876SvcOb5SL5SKg9/rCB
 ufdPSjojkGFWGziHiFaYhbuI2E+NfWLJtd+ZvWAAV+O0d8vFFSvriy9enJ8kxJwhC0ECbSKF
 Y+W1eTIhMD3aeAKY90drozWEyHhENf4l/V+Ja5vOnW+gCDQkGt2Y1lJAPPSIqZKvHzGShdh8
 DduC0U3xYkfbGAUvbxeepjgzp0uEnBXfPTy09JGpgWbg0w91GyfT/ujKaGd4vxG2Ei+MMNDm
 S1SMx7wu0evvQ5kT9NPzyq8R2GIhVSiAd2jioGuTjX6AZCFv3ToO53DliFMkVTecLptsXaes
 uUHgL9dKIfvpm+rNXRn9wAwGjk0X/A==
Message-ID: <985108b1-6d51-4458-48de-c5b96c5f14f9@redhat.com>
Date:   Tue, 16 Apr 2019 10:09:29 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.6.1
MIME-Version: 1.0
In-Reply-To: <AM6PR09MB35234C86C0502E1FAAB3A305D2240@AM6PR09MB3523.eurprd09.prod.outlook.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 16/04/19 08:58, Pascal Van Leeuwen wrote:
>>> Besides that, they are in heavy practical use in mainland China, 
>>> usually as direct replacements for SHA2-256 and AES in whatever 
>>> protocol or use case you need: IPsec, TLS, WPA2, XTS for disk encryption,
>>> you name it.
>>
>> How should that mean anything?
>
> Uhm ... no, the fact that something is actually *useful* to potentially
> a billion plus people doesn't mean anything ...

Useful does not mean secure, does it?  PKZIP encryption was certainly
useful back in the day, but it was not secure.

>> I did educate myself a bit, but I'm not an expert in cryptography, so I
>> would like to be sure that these are not another Speck or DUAL-EC-DRBG.
>
> Innocent until proven guilty mean anything to you?

This is not a court of justice, it's a software project.  For that
matter "certainty beyond reasonable doubt" is not a thing either in this
context.

>>  "SM2 is based on ECC(Elliptic Curve Cryptography), and uses a special
>> curve" is enough for me to see warning signs, at least without further
>> explanations,
>>
> The specification is public (if you can read Chinese, anyway), so open to
> analysis. Either way, it's quite irrelevant to Chinese organisations that
> HAVE to use SM2. And anyone else can just decide NOT to use it, you don't
> even have to compile it into your kernel. It's called freedom.

"Freedom" didn't apply when Speck was proposed for inclusion in Linux,
and I would like to make sure I don't make a mistake when adding crypto
interfaces.  If SM2/3/4 were broken, I couldn't care less if someone HAS
to use them, they can patch their kernel.  But if they're not then I
appreciate that you wrote to correct me, it's helpful.  Please
understand that 99% of the community has not ever heard of anything but
SHA-{1,2,3}, ECDSA, Ed25519, AES.  If somebody comes up with a patch
with "strange" crypto, it's up to them to say that they are secure---and
again, the key word is secure, not useful.

Paolo

>> and so does the fact that the initial SM3 values were
>> changed from SHA-2 and AFAICT there is no public justification for
>> that.
>>
> Actually, SM3 is an *improvement* on SHA-2, and there has been ample
> analysis done on that to, in fact, confirm it's (slightly) better.
> So there IS public justification. Don't shout if you don't know the
> facts.