[Openid-specs-fapi] JWT Secured Authorization Response Mode (#155)

Torsten Lodderstedt torsten at lodderstedt.net
Wed Aug 22 07:25:30 UTC 2018



> Am 22.08.2018 um 07:34 schrieb Filip Skokan <panva.ip at gmail.com>:
> 
> The point about encryption makes sense.
> 
> If a payload is encrypted for the receiving party, could JWS none be used then?

What would be the rationale?

> 
> Filip
> 
> Odesláno z iPhonu
> 
> 21. 8. 2018 v 23:57, Brian Campbell <bcampbell at pingidentity.com>:
> 
>> Thanks Filip, we'll try and ensure this makes it into the document. 
>> 
>> On Tue, Aug 21, 2018 at 2:52 PM Filip Skokan <panva.ip at gmail.com> wrote:
>> my $.02, drawing from http://openid.net/specs/oauth-v2-multiple-response-types-1_0.html
>> 
>> query.jwt response mode use with implicit and hybrid response types should have the same restriction as regular query does => MUST NOT be used.
>> 
>> Agree. Unless the response JWT is encrypted, in which case it's okay I think. 
>>  
>> fragment.jwt while weird for code flow, does not need this restriction.
>> 
>> Also agree. 
>>  
>> 
>> Best,
>> Filip
>> 
>> 
>> On Tue, Aug 21, 2018 at 9:58 PM Torsten Lodderstedt <torsten at lodderstedt.net> wrote:
>> Hi Brian, 
>> 
>> > Am 20.08.2018 um 22:59 schrieb Brian Campbell <bcampbell at pingidentity.com>:
>> > 
>> > Thanks, Torsten, for all your work and the quick updates on this. I've got the few more comments (from a not necessarily comprehensive review) below but the comments are getting more and more nitpicky rather than substantial, which to me means it's getting close to being ready. 
>> 
>> Great!
>> 
>> > 
>> > [RFC6750] & [RFC7636], are used "2. Terms and definitions" but aren't in the "1. Normative references“ 
>> 
>> Fixed. 
>> 
>> > 
>> > When FAPI is expanded anywhere it should now be Financial-grade API, no? 
>> 
>> Changed. 
>> 
>> > 
>> > I think it might be worthwhile to have a §4.1.3 that more generally speaks to other response types (like the various combinations from OIDM). It wouldn't have to cover them all specifically but maybe just say something to the effect of all authorization endpoint response parameters are conveyved as claims/parameters of the JWT. The way it is now with §4.1.1 for code and §4.1.2 for token kinda sorta suggest that those two are all that's supported. I realize other parts of the document say otherwise but I can see it being a point of confusion. 
>> 
>> Tried to incorporate this into 4.1.
>> 
>> > 
>> > I wonder if the "jwt" shortcut mode is worthwhile to have or if it's better to have the client simply be explicit about it using?
>> 
>> My feeling is the shortcut is more robust than the explicit values as it always defaults to a legal/generally accepted value for the particular response type.
>> 
>> Just to give some example of „weird" combinations: 
>> „query.jwt" and „token“ can only be used with caution.
>> Does „fragment.jwt" and „code“ make any sense?
>> 
>> > I'm not sure I have a strong opinion about it but just wanted to raise the question. If it's kept, the defaults should probably also speak to the other response types from OIDM (default for code alone is query and everything else is fragment). 
>> 
>> 
>> 
>> > http://openid.net/specs/oauth-v2-multiple-response-types-1_0.html#Combinations spells it out and maybe a reference with context of the jwt.fragment where fragment is used in OIDM and jwt.qurery where qurey is used in OIDM would work.  
>> 
>> Generalized 4.3.4 and added reference to OIDM
>> 
>> > 
>> > Probably it should also say somewhere that jwt.query encoding must not be used for response types that contain "token" or "id_token" so as to avoid leakage etc from having those things in the URL. Unless the JWT response is encrypted, in which case it would be okay. 
>> 
>> Added some text.
>> 
>> > 
>> > In 4.4: Maybe change "The key might be a private key registered with the expected issuer of the response "to  "The key might be a private key, where the corresponding public key is registered with the expected issuer of the response" or something like that just to be clear about what part of the key is used for what. 
>> 
>> adopted 
>> 
>> > 
>> > Also in 4.4 change "determine" to "determined" and "neede" to „needed"
>> 
>> fixed. 
>> 
>> > 
>> > Given that 4.4 is calling out checks on iss and aud, it should maybe also say to check the exp. That's already implied by JWT in general but seems maybe worth calling out in the processing rules along with the other checks.
>> 
>> added exp check 
>> 
>> >  
>> > 
>> > In "5. Client Metadata" and/or somewhere else in the doc, should the JWS "none" alg be prohibited? 
>> 
>> added sentence
>> 
>> > 
>> > In §5 and §6 JWS [RFC7515] is used but 7515 isn't in the references. 
>> 
>> added RFC7515 to references. 
>> 
>> Latest version can be found at https://bitbucket.org/openid/fapi/src/155-JWT-Secured-Authorization-Response-Mode/Financial_API_JWT_Secured_Authorization_Response_Mode.md
>> 
>> kind regards,
>> Torsten. 
>> 
>> > 
>> > 
>> > 
>> > 
>> > 
>> > 
>> > 
>> > 
>> > 
>> > 
>> > 
>> > 
>> > 
>> > On Mon, Aug 20, 2018 at 1:59 AM Torsten Lodderstedt via Openid-specs-fapi <openid-specs-fapi at lists.openid.net> wrote:
>> > Hi Filip, 
>> > 
>> > good point! I added text on extension parameters. 
>> > 
>> > I also added an IANA Consideration section (registration of new client registration and server metadata parameters) and text on publication of supported response mode values.
>> > 
>> > https://bitbucket.org/openid/fapi/src/155-JWT-Secured-Authorization-Response-Mode/Financial_API_JWT_Secured_Authorization_Response_Mode.md
>> > 
>> > kind regards,
>> > Torsten. 
>> > 
>> > > Am 19.08.2018 um 19:27 schrieb Filip Skokan <panva.ip at gmail.com>:
>> > > 
>> > > Hello Torsten,
>> > > 
>> > > Some specs, e.g. session management define additional authorization endpoint response parameters (session_state in case of session management). 
>> > > It’d be great to define if these additional params belong in the jwt or are sent using the regular response mode.
>> > > 
>> > > Best,
>> > > Filip
>> > > 
>> > > Odesláno z iPhonu
>> > > 
>> > > 19. 8. 2018 v 17:47, Torsten Lodderstedt via Openid-specs-fapi <openid-specs-fapi at lists.openid.net>:
>> > > 
>> > >> Hi all,
>> > >> 
>> > >> I incorporated Brian’s and Vladimir’s comments/proposals.
>> > >> 
>> > >> Here is a list of the changes:
>> > >> - moved state into the JWT
>> > >> - adopted processing rules to logic as defined below
>> > >> - added response mode values to be able to distinguish query, fragment and form post encoding 
>> > >> - added form post encoding
>> > >> - added client and server metadata
>> > >> 
>> > >> Take a look: https://bitbucket.org/openid/fapi/src/155-JWT-Secured-Authorization-Response-Mode/Financial_API_JWT_Secured_Authorization_Response_Mode.md
>> > >> 
>> > >> Looking forward for your feedback. 
>> > >> 
>> > >> kind regards,
>> > >> Torsten.
>> > >> 
>> > >>> Am 17.08.2018 um 19:24 schrieb Brian Campbell <bcampbell at pingidentity.com>:
>> > >>> 
>> > >>> Yeah, I think that captures the general processing flow. 
>> > >>> 
>> > >>> On Fri, Aug 17, 2018 at 8:50 AM Torsten Lodderstedt <torsten at lodderstedt.net> wrote:
>> > >>> Hi Brian,
>> > >>> 
>> > >>>> Am 17.08.2018 um 15:39 schrieb Brian Campbell <bcampbell at pingidentity.com>:
>> > >>>> 
>> > >>>> Good point. OIDC Core (http://openid.net/specs/openid-connect-core-1_0.html#Security) does not discuss this attack angle. From your perspective, what is the typical way to detect crafted/modified ID Tokens in the id_token flow? 
>> > >>>> 
>> > >>>> Checking the signature. But if the issuer isn't known or expected, don't go trying to find keys for it, just reject the token.
>> > >>> 
>> > >>> 
>> > >>> I would like to summarize the discussion regarding handling of state value and response processing. 
>> > >>> 
>> > >>> From what I understand, the processing would work as follows (assuming the „state" is carried in the JWT):
>> > >>> 
>> > >>> 1) decrypt JWT using the client's private key - the key is determine by the „kid“ header parameter
>> > >>> 2) obtain „state“ from JWT
>> > >>> 3) check binding of state value to user agent, if check fails - abort processing
>> > >>> 4) obtain „iss" from JWT
>> > >>> 5) check whether „iss" is known and expected („aud“ could be checked in this step as well), if not abort processing
>> > >>> 6) obtain signing key based on „iss“ and „kid"
>> > >>> 7) check signature, if signature validation fails - abort processing
>> > >>> 8) use response parameters
>> > >>> 
>> > >>> Does this capture your thoughts correctly? 
>> > >>> 
>> > >>> Kind regards,
>> > >>> Torsten.
>> > >>> 
>> > >>> CONFIDENTIALITY NOTICE: This email may contain confidential and privileged material for the sole use of the intended recipient(s). Any review, use, distribution or disclosure by others is strictly prohibited.  If you have received this communication in error, please notify the sender immediately by e-mail and delete the message and any file attachments from your computer. Thank you.
>> > >> 
>> > >> _______________________________________________
>> > >> Openid-specs-fapi mailing list
>> > >> Openid-specs-fapi at lists.openid.net
>> > >> http://lists.openid.net/mailman/listinfo/openid-specs-fapi
>> > 
>> > _______________________________________________
>> > Openid-specs-fapi mailing list
>> > Openid-specs-fapi at lists.openid.net
>> > http://lists.openid.net/mailman/listinfo/openid-specs-fapi
>> > 
>> > CONFIDENTIALITY NOTICE: This email may contain confidential and privileged material for the sole use of the intended recipient(s). Any review, use, distribution or disclosure by others is strictly prohibited.  If you have received this communication in error, please notify the sender immediately by e-mail and delete the message and any file attachments from your computer. Thank you.
>> 
>> 
>> CONFIDENTIALITY NOTICE: This email may contain confidential and privileged material for the sole use of the intended recipient(s). Any review, use, distribution or disclosure by others is strictly prohibited.  If you have received this communication in error, please notify the sender immediately by e-mail and delete the message and any file attachments from your computer. Thank you.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 3872 bytes
Desc: not available
URL: <http://lists.openid.net/pipermail/openid-specs-fapi/attachments/20180822/862ceea1/attachment.p7s>


More information about the Openid-specs-fapi mailing list