Implicit trust #82

mcr · 2020-04-28T14:20:18Z

replace pull request #60 with one we can edit.
This attempts to establish the architectural basis for implicit trust as a result of links.

Update draft-ietf-rats-architecture.md Update draft-ietf-rats-architecture.md Update draft-ietf-rats-architecture.md Co-Authored-By: Dave Thaler <dthaler@microsoft.com> Update draft-ietf-rats-architecture.md Co-Authored-By: Dave Thaler <dthaler@microsoft.com> Update draft-ietf-rats-architecture.md Co-Authored-By: Dave Thaler <dthaler@microsoft.com> Update draft-ietf-rats-architecture.md Co-Authored-By: Dave Thaler <dthaler@microsoft.com> Update draft-ietf-rats-architecture.md Co-Authored-By: Dave Thaler <dthaler@microsoft.com> Update draft-ietf-rats-architecture.md Co-Authored-By: Dave Thaler <dthaler@microsoft.com> Update draft-ietf-rats-architecture.md

mcr · 2020-04-28T14:52:03Z

draft-ietf-rats-architecture.md

+As a result, the Verifier may be able to trust the attestation evidence from the device without
+an additional endorsement or even a cryptographically-verifiable signature of the


Suggested change

As a result, the Verifier may be able to trust the attestation evidence from the device without

an additional endorsement or even a cryptographically-verifiable signature of the

As a result, an Appraisal Policy for the Verifier may be possible that trusts the attestation evidence from the device without

endorsement or cryptographically-verifiable signature of the

Maybe noun/verb mismatch? I don't think a policy trusts something, I think the Verifier trusts something based on policy.

dthaler · 2020-05-04T21:37:36Z

draft-ietf-rats-architecture.md

+communicate over a link that is established using a Root of Trust.  An example of such communications
+is over a cellular link, where the link is established by the Attester leveraging an enclave (e.g., SIM card).  The Verifier may have established the communications link and verified


Two sentences starting "As an example, ... An example of such ..." reads poorly.

Suggested change

communicate over a link that is established using a Root of Trust. An example of such communications

is over a cellular link, where the link is established by the Attester leveraging an enclave (e.g., SIM card). The Verifier may have established the communications link and verified

communicate over a link that is established using a Root of Trust, such as a cellular link established by the Attester leveraging an enclave (e.g., SIM card). The Verifier may have established the communications link and verified

I can't tell if this paragraph is intended to add intuition to "Root of Trust" or to describe the duties of a Verifier that leverages a pre-existing comms session to protect the integrity of Evidence (and to ascribe the semantics of the key that the Attester 'claims' the assertions in the Evidence are accurate representation of current state of the Target environment).

dthaler · 2020-05-04T22:08:20Z

draft-ietf-rats-architecture.md

+or may have received evidence that the communications link is anchored to a
+Root of Trust from an entity that established the communications link.


Redundant with lines 704-706

dthaler · 2020-05-04T22:09:22Z

draft-ietf-rats-architecture.md

+Root of Trust from an entity that established the communications link.
+In the latter case, anchoring the communications link to a Root of Trust would mean
+that this entity only established a communications link with the attesting
+device after verifying that the device had a Root of Trust.


I don't think this wording is correct. Maybe "a Root of Trust that this entity trusts"?

It is at least verbose.

dthaler · 2020-05-04T22:09:37Z

draft-ietf-rats-architecture.md

+that this entity only established a communications link with the attesting
+device after verifying that the device had a Root of Trust.
+
+As a result, the Verifier may be able to trust the attestation evidence from the device without


Suggested change

As a result, the Verifier may be able to trust the attestation evidence from the device without

As a result, the Verifier may be able to trust the attestation Evidence from the Attester without

dthaler · 2020-05-04T22:11:05Z

draft-ietf-rats-architecture.md

+As a result, the Verifier may be able to trust the attestation evidence from the device without
+an additional endorsement or even a cryptographically-verifiable signature of the


Maybe noun/verb mismatch? I don't think a policy trusts something, I think the Verifier trusts something based on policy.

dthaler · 2020-05-04T22:11:22Z

draft-ietf-rats-architecture.md

+
+As a result, the Verifier may be able to trust the attestation evidence from the device without
+an additional endorsement or even a cryptographically-verifiable signature of the
+evidence.  Note that the appraisal policy employed by the Verifier may take into account the


Suggested change

evidence. Note that the appraisal policy employed by the Verifier may take into account the

Evidence. Note that the Appraisal Policy employed by the Verifier may take into account the

dthaler · 2020-05-04T22:11:40Z

draft-ietf-rats-architecture.md

+an additional endorsement or even a cryptographically-verifiable signature of the
+evidence.  Note that the appraisal policy employed by the Verifier may take into account the
+transient nature of the communications link security.  For instance, once the link is torn down
+then the Evidence may not be trusted until it is conveyed again over a re-established link.


Suggested change

then the Evidence may not be trusted until it is conveyed again over a re-established link.

then the Evidence might not be trusted until it is conveyed again over a re-established link.

This whole section seems to be more that of a use case that describes an architectural principle or concept than directly stating the principle or concept.

I think the principle is:

A conveyance protocol that is authenticated and integrity protected can be used to convey unprotected Evidence IF the following properties hold:
a) The key used to authenticate and integrity protect the conveyance channel is trusted by the Verifier to speak for the Attesting Environment that collected claims about the Target Environment.
b) The Evidence in the conveyance channel is supplied by the Attesting Environment.
c) The Root of Trust protects the key and the Attesting Environment with equivalent strength.

Agree and I like Ned's articulation above. Maybe the PR should just say what's in Ned's principle?

I have no objection. It is concise and captures my original inten. @nedmsmith - will you be taking the lead on the PR revision.

Added paragraph sumarizing 3 properties or assumptions that must be in place if a conveyance protocol is to be used to protect Evidence.

henkbirkholz · 2020-05-19T13:51:53Z

draft-ietf-rats-architecture.md

@@ -697,6 +697,13 @@ for by hardware or by ROM code, especially if such hardware is
 physically resistant to hardware tampering.  The component that is
 implicitly trusted is often referred to as a Root of Trust.

+A conveyance protocol that is authenticated and integrity protected can be used


I assume what is meant here is:

evidence is protected

remote peers are (mutually) authenticated

henkbirkholz · 2020-05-19T13:52:25Z

draft-ietf-rats-architecture.md

+A conveyance protocol that is authenticated and integrity protected can be used
+to convey unprotected Evidence, assuming the following properties exists:
+
+   1. The key used to authenticate and integrity protect the conveyance channel is trusted by the Verifier to speak for the Attesting Environment that collected claims about the Target Environment.


keys? of at least two remote peers? We are talking about a "Secure Channel" to convey unprotected Evidence right?

Also? In theory, unprotected Evidence are just Claims?

I am not sure if we should water down evidence, in general. Evidence should be tamper-evident. In consequent, messing with evidence conveyed via "secure channel" must be evident with a similar level of assurance.

dthaler · 2020-05-19T14:03:34Z

draft-ietf-rats-architecture.md

+A conveyance protocol that is authenticated and integrity protected can be used
+to convey unprotected Evidence, assuming the following properties exists:
+
+   1. The key used to authenticate and integrity protect the conveyance channel is trusted by the Verifier to speak for the Attesting Environment that collected claims about the Target Environment.


"the" attesting environment and "the" target environment imply this does not apply to layered evidence or composite devices, is that intentional?

dthaler · 2020-05-19T14:03:59Z

metadata.min.js

@@ -0,0 +1 @@
+async function addMetadata(){try{const e=document.styleSheets[0].cssRules;for(let t=0;t<e.length;t++)if(/#identifiers/.exec(e[t].selectorText)){const a=e[t].cssText.replace("#identifiers","#external-updates");document.styleSheets[0].insertRule(a,document.styleSheets[0].cssRules.length)}}catch(e){console.log(e)}const e=document.getElementById("external-metadata");if(e)try{var t,a="",o=function(e){const t=document.getElementsByTagName("meta");for(let a=0;a<t.length;a++)if(t[a].getAttribute("name")===e)return t[a].getAttribute("content");return""}("rfc.number");if(o){t="https://www.rfc-editor.org/rfc/rfc"+o+".json";try{const e=await fetch(t);a=await e.json()}catch(e){t=document.URL.indexOf("html")>=0?document.URL.replace(/html$/,"json"):document.URL+".json";const o=await fetch(t);a=await o.json()}}if(!a)return;e.style.display="block";const s="",d="https://datatracker.ietf.org/doc",n="https://datatracker.ietf.org/ipr/search",c="https://www.rfc-editor.org/info",l=a.doc_id.toLowerCase(),i=a.doc_id.slice(0,3).toLowerCase(),f=a.doc_id.slice(3).replace(/^0+/,""),u={status:"Status",obsoletes:"Obsoletes",obsoleted_by:"Obsoleted By",updates:"Updates",updated_by:"Updated By",see_also:"See Also",errata_url:"Errata"};let h="<dl style='overflow:hidden' id='external-updates'>";["status","obsoletes","obsoleted_by","updates","updated_by","see_also","errata_url"].forEach(e=>{if("status"==e){a[e]=a[e].toLowerCase();var t=a[e].split(" "),o=t.length,w="",p=1;for(let e=0;e<o;e++)p<o?w=w+r(t[e])+" ":w+=r(t[e]),p++;a[e]=w}else if("obsoletes"==e||"obsoleted_by"==e||"updates"==e||"updated_by"==e){var g,m="",b=1;g=a[e].length;for(let t=0;t<g;t++)a[e][t]&&(a[e][t]=String(a[e][t]).toLowerCase(),m=b<g?m+"<a href='"+s+"/rfc/".concat(a[e][t])+"'>"+a[e][t].slice(3)+"</a>, ":m+"<a href='"+s+"/rfc/".concat(a[e][t])+"'>"+a[e][t].slice(3)+"</a>",b++);a[e]=m}else if("see_also"==e){var y,L="",C=1;y=a[e].length;for(let t=0;t<y;t++)if(a[e][t]){a[e][t]=String(a[e][t]);var _=a[e][t].slice(0,3),v=a[e][t].slice(3).replace(/^0+/,"");L=C<y?"RFC"!=_?L+"<a href='"+s+"/info/"+_.toLowerCase().concat(v.toLowerCase())+"'>"+_+" "+v+"</a>, ":L+"<a href='"+s+"/info/"+_.toLowerCase().concat(v.toLowerCase())+"'>"+v+"</a>, ":"RFC"!=_?L+"<a href='"+s+"/info/"+_.toLowerCase().concat(v.toLowerCase())+"'>"+_+" "+v+"</a>":L+"<a href='"+s+"/info/"+_.toLowerCase().concat(v.toLowerCase())+"'>"+v+"</a>",C++}a[e]=L}else if("errata_url"==e){var R="";R=a[e]?R+"<a href='"+a[e]+"'>Errata exist</a> | <a href='"+d+"/"+l+"'>Datatracker</a>| <a href='"+n+"/?"+i+"="+f+"&submit="+i+"'>IPR</a> | <a href='"+c+"/"+l+"'>Info page</a>":"<a href='"+d+"/"+l+"'>Datatracker</a> | <a href='"+n+"/?"+i+"="+f+"&submit="+i+"'>IPR</a> | <a href='"+c+"/"+l+"'>Info page</a>",a[e]=R}""!=a[e]?"Errata"==u[e]?h+=`<dt>More info:</dt><dd>${a[e]}</dd>`:h+=`<dt>${u[e]}:</dt><dd>${a[e]}</dd>`:"Errata"==u[e]&&(h+=`<dt>More info:</dt><dd>${a[e]}</dd>`)}),h+="</dl>",e.innerHTML=h}catch(e){console.log(e)}else console.log("Could not locate metadata <div> element");function r(e){return e.charAt(0).toUpperCase()+e.slice(1)}}window.removeEventListener("load",addMetadata),window.addEventListener("load",addMetadata);


What is this file for?

draft-ietf-rats-architecture.md

dthaler · 2020-05-19T14:30:03Z

draft-ietf-rats-architecture.md

+to convey unprotected Evidence, assuming the following properties exists:
+
+   1. The key used to authenticate and integrity protect the conveyance channel is trusted by the Verifier to speak for the Attesting Environment that collected claims about the Target Environment.
+   2. The Evidence in the conveyance channel is supplied by the Attesting Environment.


same question about "the Attesting Environment"... which Attesting Environment? Also the phrase reads as a tautology, can we wordsmith somehow?

draft-ietf-rats-architecture.md

Giri Mandyam and others added 2 commits April 28, 2020 10:16

remove trailing whitespace

c4b3972

mcr mentioned this pull request Apr 28, 2020

Update Trust Model with Implicit Trust Example #60

Closed

mcr commented Apr 28, 2020

View reviewed changes

mcr mentioned this pull request Apr 28, 2020

Security Considerations for Implicit Trust Model #83

Closed

mcr requested a review from gmandyam April 28, 2020 14:56

dthaler reviewed May 4, 2020

View reviewed changes

nedmsmith added 2 commits May 18, 2020 16:05

Issue82

4b3c327

Added paragraph sumarizing 3 properties or assumptions that must be in place if a conveyance protocol is to be used to protect Evidence.

Removed previous text related issue 82

364b675

henkbirkholz reviewed May 19, 2020

View reviewed changes

dthaler reviewed May 19, 2020

View reviewed changes

mcr commented May 19, 2020

View reviewed changes

draft-ietf-rats-architecture.md Outdated Show resolved Hide resolved

ietf-rats-wg deleted a comment from nedmsmith May 19, 2020

dthaler reviewed May 19, 2020

View reviewed changes

mcr commented May 19, 2020

View reviewed changes

draft-ietf-rats-architecture.md Outdated Show resolved Hide resolved

mcr added 3 commits May 19, 2020 10:42

Update draft-ietf-rats-architecture.md

280bdd4

Update draft-ietf-rats-architecture.md

c15ecbb

Delete metadata.min.js

8988bb8

dthaler self-requested a review May 19, 2020 14:44

dthaler approved these changes May 19, 2020

View reviewed changes

mcr commented May 19, 2020

View reviewed changes

draft-ietf-rats-architecture.md Outdated Show resolved Hide resolved

Update draft-ietf-rats-architecture.md

bd7ba59

mcr commented May 19, 2020

View reviewed changes

draft-ietf-rats-architecture.md Outdated Show resolved Hide resolved

Update draft-ietf-rats-architecture.md

e3ac83c

mcr commented May 19, 2020

View reviewed changes

draft-ietf-rats-architecture.md Outdated Show resolved Hide resolved

mcr commented May 19, 2020

View reviewed changes

draft-ietf-rats-architecture.md Outdated Show resolved Hide resolved

Apply suggestions from code review

4612651

mcr merged commit 835a712 into master May 19, 2020

mcr deleted the implicit-trust branch May 19, 2020 14:47

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Implicit trust #82

Implicit trust #82

mcr commented Apr 28, 2020

mcr Apr 28, 2020 •

edited

Loading

dthaler May 4, 2020

dthaler May 4, 2020

nedmsmith May 5, 2020

dthaler May 4, 2020

dthaler May 4, 2020

nedmsmith May 5, 2020

dthaler May 4, 2020

dthaler May 4, 2020

dthaler May 4, 2020

dthaler May 4, 2020

nedmsmith May 5, 2020

dthaler May 5, 2020

gmandyam May 5, 2020

henkbirkholz May 19, 2020

henkbirkholz May 19, 2020

dthaler May 19, 2020

dthaler May 19, 2020

dthaler May 19, 2020

		As a result, the Verifier may be able to trust the attestation evidence from the device without
		an additional endorsement or even a cryptographically-verifiable signature of the

		communicate over a link that is established using a Root of Trust. An example of such communications
		is over a cellular link, where the link is established by the Attester leveraging an enclave (e.g., SIM card). The Verifier may have established the communications link and verified

		or may have received evidence that the communications link is anchored to a
		Root of Trust from an entity that established the communications link.

	evidence. Note that the appraisal policy employed by the Verifier may take into account the
	Evidence. Note that the Appraisal Policy employed by the Verifier may take into account the

	then the Evidence may not be trusted until it is conveyed again over a re-established link.
	then the Evidence might not be trusted until it is conveyed again over a re-established link.

		@@ -0,0 +1 @@
		async function addMetadata(){try{const e=document.styleSheets[0].cssRules;for(let t=0;t<e.length;t++)if(/#identifiers/.exec(e[t].selectorText)){const a=e[t].cssText.replace("#identifiers","#external-updates");document.styleSheets[0].insertRule(a,document.styleSheets[0].cssRules.length)}}catch(e){console.log(e)}const e=document.getElementById("external-metadata");if(e)try{var t,a="",o=function(e){const t=document.getElementsByTagName("meta");for(let a=0;a<t.length;a++)if(t[a].getAttribute("name")===e)return t[a].getAttribute("content");return""}("rfc.number");if(o){t="https://www.rfc-editor.org/rfc/rfc"+o+".json";try{const e=await fetch(t);a=await e.json()}catch(e){t=document.URL.indexOf("html")>=0?document.URL.replace(/html$/,"json"):document.URL+".json";const o=await fetch(t);a=await o.json()}}if(!a)return;e.style.display="block";const s="",d="https://datatracker.ietf.org/doc",n="https://datatracker.ietf.org/ipr/search",c="https://www.rfc-editor.org/info",l=a.doc_id.toLowerCase(),i=a.doc_id.slice(0,3).toLowerCase(),f=a.doc_id.slice(3).replace(/^0+/,""),u={status:"Status",obsoletes:"Obsoletes",obsoleted_by:"Obsoleted By",updates:"Updates",updated_by:"Updated By",see_also:"See Also",errata_url:"Errata"};let h="<dl style='overflow:hidden' id='external-updates'>";["status","obsoletes","obsoleted_by","updates","updated_by","see_also","errata_url"].forEach(e=>{if("status"==e){a[e]=a[e].toLowerCase();var t=a[e].split(" "),o=t.length,w="",p=1;for(let e=0;e<o;e++)p<o?w=w+r(t[e])+" ":w+=r(t[e]),p++;a[e]=w}else if("obsoletes"==e\|\|"obsoleted_by"==e\|\|"updates"==e\|\|"updated_by"==e){var g,m="",b=1;g=a[e].length;for(let t=0;t<g;t++)a[e][t]&&(a[e][t]=String(a[e][t]).toLowerCase(),m=b<g?m+"<a href='"+s+"/rfc/".concat(a[e][t])+"'>"+a[e][t].slice(3)+"</a>, ":m+"<a href='"+s+"/rfc/".concat(a[e][t])+"'>"+a[e][t].slice(3)+"</a>",b++);a[e]=m}else if("see_also"==e){var y,L="",C=1;y=a[e].length;for(let t=0;t<y;t++)if(a[e][t]){a[e][t]=String(a[e][t]);var _=a[e][t].slice(0,3),v=a[e][t].slice(3).replace(/^0+/,"");L=C<y?"RFC"!=_?L+"<a href='"+s+"/info/"+_.toLowerCase().concat(v.toLowerCase())+"'>"+_+" "+v+"</a>, ":L+"<a href='"+s+"/info/"+_.toLowerCase().concat(v.toLowerCase())+"'>"+v+"</a>, ":"RFC"!=_?L+"<a href='"+s+"/info/"+_.toLowerCase().concat(v.toLowerCase())+"'>"+_+" "+v+"</a>":L+"<a href='"+s+"/info/"+_.toLowerCase().concat(v.toLowerCase())+"'>"+v+"</a>",C++}a[e]=L}else if("errata_url"==e){var R="";R=a[e]?R+"<a href='"+a[e]+"'>Errata exist</a> \| <a href='"+d+"/"+l+"'>Datatracker</a>\| <a href='"+n+"/?"+i+"="+f+"&submit="+i+"'>IPR</a> \| <a href='"+c+"/"+l+"'>Info page</a>":"<a href='"+d+"/"+l+"'>Datatracker</a> \| <a href='"+n+"/?"+i+"="+f+"&submit="+i+"'>IPR</a> \| <a href='"+c+"/"+l+"'>Info page</a>",a[e]=R}""!=a[e]?"Errata"==u[e]?h+=`<dt>More info:</dt><dd>${a[e]}</dd>`:h+=`<dt>${u[e]}:</dt><dd>${a[e]}</dd>`:"Errata"==u[e]&&(h+=`<dt>More info:</dt><dd>${a[e]}</dd>`)}),h+="</dl>",e.innerHTML=h}catch(e){console.log(e)}else console.log("Could not locate metadata <div> element");function r(e){return e.charAt(0).toUpperCase()+e.slice(1)}}window.removeEventListener("load",addMetadata),window.addEventListener("load",addMetadata);

Implicit trust #82

Implicit trust #82

Conversation

mcr commented Apr 28, 2020

mcr Apr 28, 2020 • edited Loading

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

mcr Apr 28, 2020 •

edited

Loading