IETF Logo Mail Archive

Re: [Rats] Android attestations: Re: draft-richardson-rats-usecases-00 comments

Anders Rundgren <anders.rundgren.net@gmail.com> Wed, 19 June 2019 06:02 UTC

Return-Path: <anders.rundgren.net@gmail.com>
X-Original-To: rats@ietfa.amsl.com
Delivered-To: rats@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 65A6F1203BA for <rats@ietfa.amsl.com>; Tue, 18 Jun 2019 23:02:59 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.998
X-Spam-Level:
X-Spam-Status: No, score=-1.998 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id bEAGZoB8jJne for <rats@ietfa.amsl.com>; Tue, 18 Jun 2019 23:02:57 -0700 (PDT)
Received: from mail-wr1-x429.google.com (mail-wr1-x429.google.com [IPv6:2a00:1450:4864:20::429]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id E2C73120089 for <rats@ietf.org>; Tue, 18 Jun 2019 23:02:56 -0700 (PDT)
Received: by mail-wr1-x429.google.com with SMTP id c2so1891431wrm.8 for <rats@ietf.org>; Tue, 18 Jun 2019 23:02:56 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=NDSpR/d2zEiGWNfVfVnRqUEKQjpOdqrhuh58K2xY2fQ=; b=WX4U6aXPyEV2BPdNQVy0tVxpRxbwfxahwpOgEHH1EO/zUPX9vNNIyFEhExF+UDJaL3 K3D2a6EyNm3SkuTGyME9w7ARVZD/nZp1XZ+DkvhNPzIYaptFs2I6UslPhEFQ0UD0xb86 q9g7aAO7zvIk64txW5rEu/VHHrTid3lZP6HCq72qta4rvO+49qnQzD9WrVWFXwxRu6cK IKLkOLTKEbPgSvkY8DlG9rE1DVwTt++uS5JND+HxuATcdbiOxWl0FompyHg1p0byzEe3 S9PhA97HLDMTz988r3hZAFxbupPdaxrHhfsaFecamUdPwzvzxHEv2YozG3uFJMFJPs+R eJwQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=NDSpR/d2zEiGWNfVfVnRqUEKQjpOdqrhuh58K2xY2fQ=; b=MgQ20L8ZMdcXpc6oHJCQwQDQxNc7hvn8hayNTlraCjUQwuAUNCuLjG1Dw/CYMqPk7S 4YM/yYd0Sbr0r+MGNikuDviymf1Th/4UgHEqRFV/sKSvTW4mNnd/IXfiAdk+Jtb4N9wI BYIPCldNtFqaCx38s1ufpizVXjMnUgVutUAdDbQWEjho1diZmEL4AePkj6BzZcAPb0cx 0fPjQxd8JBrX8JmfbvOTsHZpDD375sgSrXOQznS1Wm67yv3QhTyv9+9QeQpsbIYpS8Jh jG57w6DLXigcx4EaonfaIymsdT9Y+0w25CbaUTXOMvGYRV4u/VA16KYqxk+W3yL0847F wxmQ==
X-Gm-Message-State: APjAAAUo7rqXjKUq7dMiNv9WU3YqMq1LZ5VJ/Ecl0qb3E3tWg7SXWXE5 JH5q765wljwfcGx0OzwSfkU=
X-Google-Smtp-Source: APXvYqz/jUK3yV3ezpcq3lIp4cqULfwJEbn3uB6GZon93EyJNamBgcKote7fyvbOD3EINJCNvmTN1Q==
X-Received: by 2002:a5d:6389:: with SMTP id p9mr72822171wru.297.1560924175420; Tue, 18 Jun 2019 23:02:55 -0700 (PDT)
Received: from [192.168.1.79] (25.131.146.77.rev.sfr.net. [77.146.131.25]) by smtp.googlemail.com with ESMTPSA id w23sm345489wmc.38.2019.06.18.23.02.54 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Jun 2019 23:02:54 -0700 (PDT)
To: Michael Richardson <mcr+ietf@sandelman.ca>
Cc: "rats@ietf.org" <rats@ietf.org>, Anthony Nadalin <tonynad=40microsoft.com@dmarc.ietf.org>, Laurence Lundblade <lgl@island-resort.com>, Thomas Fossati <Thomas.Fossati@arm.com>
References: <MW2PR00MB03963ABEB87211AD28A16240A6490@MW2PR00MB0396.namprd00.prod.outlook.com> <12503.1552447661@localhost> <219648D6-188A-429D-A13F-ED6155DE9016@island-resort.com> <14288.1553710783@dooku.sandelman.ca> <4EB6FF13-2DAF-4BDC-AC90-C46720D61AF0@arm.com> <bf003513-209a-7d5f-a9a5-58ade6c23545@gmail.com> <21417.1560911502@dooku.sandelman.ca>
From: Anders Rundgren <anders.rundgren.net@gmail.com>
Message-ID: <fbc05f84-232b-7ca6-47c1-9b23d73e47ca@gmail.com>
Date: Wed, 19 Jun 2019 08:02:53 +0200
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.1
MIME-Version: 1.0
In-Reply-To: <21417.1560911502@dooku.sandelman.ca>
Content-Type: text/plain; charset="utf-8"; format="flowed"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/rats/Wfd5QuCWTUmPhBozaLApqP7mrKI>
Subject: Re: [Rats] Android attestations: Re: draft-richardson-rats-usecases-00 comments
X-BeenThere: rats@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Remote Attestation Procedures <rats.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rats>, <mailto:rats-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/rats/>
List-Post: <mailto:rats@ietf.org>
List-Help: <mailto:rats-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rats>, <mailto:rats-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 19 Jun 2019 06:03:00 -0000

On 2019-06-19 04:31, Michael Richardson wrote:
> 
> Anders Rundgren <anders.rundgren.net@gmail.com> wrote:
>      > Here you have another link:
>      > https://developer.android.com/training/articles/security-key-attestation
> 
>      > As an application developer I find this scheme and the associated
>      > "AndroidKeyStore" quite impractical.  The recent addition of
>      > "StrongBox" makes it worse.
> 
> Interesting. What is it that you find that you can not do?

A mechanism that only attests keys cannot (securely) be used for provisioning anything but keys.

> 
>      > With a two-level TEE/SE session-key based scheme you only need to
>      > attest the session permitting you to perform any number of secure
>      > operations and close the session with a "commit" which in turn responds
>      > with a (session signed) message to the SP that everything went right.
> 
> Or is this what you wish you had?

In the absence of installable TA support, I have implemented this in Android as a SW emulator [1]. It is a part of the Saturn [3] payment authorization system I'm working on.

As I have tried to describe [2], this concept also relieves you from (IMO) unwanted/unnecessary dependencies on provisioning protocol formats.

Anders
1] https://github.com/cyberphone/webpkisuite-4-android/blob/master/app/src/main/java/org/webpki/mobile/android/sks/AndroidSKSImplementation.java
2] https://github.com/ietf-teep/architecture/issues/52
3] https://cyberphone.github.io/doc/two-visions-4-mobile-payments.pdf

> 
> 
> --
> Michael Richardson <mcr+IETF@sandelman.ca>, Sandelman Software Works
>   -= IPv6 IoT consulting =-
> 
> 
> 
> 
> _______________________________________________
> RATS mailing list
> RATS@ietf.org
> https://www.ietf.org/mailman/listinfo/rats
>

v2.23.0 | Report a Bug | By Email