Re: [OAUTH-WG] Token Chaining Use Case
Because many implementations (including mine which does support my old token chaining draft) treat access tokens and refresh tokens separately in terms of data store and structure. Additionally, the refresh token is tied to the client and presented by the client. But in this case it's someone downstream, an RS, presenting the token. So unlike a refresh token being presented by the one it was issued to, this token is being presented by someone it was presented to. The feeling is close, but not quite the same in either development or assumptions. -- Justin / Sent from my phone / Original message From: Bill Mills wmills_92...@yahoo.com Date: 03/26/2015 2:24 PM (GMT-06:00) To: Justin Richer jric...@mit.edu, oauth@ietf.org oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case So why can't the access tokne simply be re-used as a refresh token? Why would it need a new grant type at all? On Thursday, March 26, 2015 11:31 AM, Justin Richer jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been passed around. Note that service A or the Client can also request a downscoped token with [ C ] to call service C directly as well, and C doesn’t have to care how it got there. In other words, it lets the client software be very, very dumb. It doesn’t have to do any special processing, doesn’t have to know what’s in the token, it just follows the recipe of “I got a token, I get another token based on this to call someone else”. It’s also analogous to the refresh token flow, but with access tokens going in and out. I’ve deployed this setup several times in different service deployments. Even though there is a performance hit in the additional round trips (as Phil brought up in another thread), in these cases the desire to have the tokens hold least privilege access rights (smallest set of scopes per service) outweighed any performance hit (which was shown to be rather small in practice). What I want is for the token swap draft to define or use a mechanism that allows us to do this. I think we can do that pretty easily by adjusting the token swap syntax and language, and explicitly calling out the semantic processing portion (the current core of the document) for what it is: a way for a token issuer to communicate to a token service specific actions. At a high level, the spec would be something like: 1. How to swap a token at an AS 1. Send a request to the token endpoint with a new grant type, and a token (of any type/format/flavor) on the way in 2. Get back a new token in a token response 2. Communicating act as / on behalf of semantics via a JWT assertion 1. How to create (as an AS/RS/client/other issuer) a JWT with act-as semantics 2. What to do (as an AS/RS) with a JWT with act-as semantics 3. How to create a JWT with on-behalf-of semeantics 4. What to do with a JWT with on-behalf-of-semantics 5. How to possibly represent these semantics with something other than a JWT Section 2 uses the syntax from section 1. Other applications, like the one I laid out above, can use the syntax from section 1 as well. This works for structured, unstructured, self-generated, cross-domain, within-domain, and other tokens. — Justin ___ OAuth mailing list OAuth@ietf.org https://www.ietf.org/mailman/listinfo/oauth ___ OAuth mailing list OAuth@ietf.org https://www.ietf.org/mailman/listinfo/oauth
Re: [OAUTH-WG] Token Chaining Use Case
See below Phil On Mar 26, 2015, at 15:15, Justin Richer jric...@mit.edu wrote: Your service layout will determine whether or not each bit calls the same AS that issued the original token, since you can easily do it across boundaries if your AS takes in cross domain tokens. That’s another benefit of having it be a generic token swap, you can build it out using the same mechanism and get both behaviors. The AS could reject the swap for any number of conditions: wrong client asked, token is expired, scopes don’t align, bad token, etc. You can always optimize your system such that you just send a high-powered token down the chain, in which case you’re not using token swapping. This is not for those cases, obviously. This is for the cases when you *are* doing token swapping and usually downscoping the privileges. There is no high power token in my new proposal. Each server must act on its own authority with its own token. The original at is passed as evidence of scoped authority to the internal services. There is no super token. — Justin On Mar 26, 2015, at 2:53 PM, Phil Hunt phil.h...@oracle.com wrote: What if A calls be with it’s own authorization token (server token ST1) and passes AT1 in another header e.g. on-behalf-of. You save a call and can still check the scope downstream. Further, service B and C can each check whether ST1 and ST2 had the right to wield AT1 even when AT1’s POP proof is a proof of the external client. The only reason I can think to call the AS is if there is some dynamic condition that might cause an AS to reject the swap. If AT1 is valid, I can’t think of another reason why the answer isn’t already YES for all calls. If its no, its likely a permanent configuration problem not a dynamic decision. In other words, B always expects A to call it on behalf of some one. Likewise, C is always expecting B. Phil @independentid www.independentid.com phil.h...@oracle.com On Mar 26, 2015, at 1:31 PM, Justin Richer jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been passed around. Note that service A or the Client can also request a downscoped token with [ C ] to call service C directly as well, and C doesn’t have to care how it got there. In other words, it lets the client software be very, very dumb. It doesn’t have to do any special processing, doesn’t have to know what’s in the token, it just follows the recipe of “I got a token, I get another token based on this to call someone else”. It’s also analogous to the refresh token flow, but with access tokens going in and out. I’ve deployed this setup several times in different service deployments. Even though there is a performance hit in the additional round trips (as Phil brought up in another thread), in these cases the desire to have the tokens hold least privilege access rights (smallest set of scopes per service) outweighed any performance hit (which was shown to be rather small in practice). What I want is for the token swap draft to define or use a mechanism that allows us to do this. I think we can do that pretty easily by adjusting the token swap syntax and language, and explicitly calling out the semantic processing portion (the current core of the document) for what it is: a way for a token issuer to communicate to a token service specific actions. At a high level, the spec would be something like: 1. How to swap a token at an AS 1. Send a request to the token endpoint with a new grant type, and a token (of any type/format/flavor) on the way in 2. Get back a new token in a token response 2. Communicating act as / on behalf of semantics via a JWT assertion 1. How to create (as an
Re: [OAUTH-WG] Token Chaining Use Case
What if A calls be with it’s own authorization token (server token ST1) and passes AT1 in another header e.g. on-behalf-of. You save a call and can still check the scope downstream. Further, service B and C can each check whether ST1 and ST2 had the right to wield AT1 even when AT1’s POP proof is a proof of the external client. The only reason I can think to call the AS is if there is some dynamic condition that might cause an AS to reject the swap. If AT1 is valid, I can’t think of another reason why the answer isn’t already YES for all calls. If its no, its likely a permanent configuration problem not a dynamic decision. In other words, B always expects A to call it on behalf of some one. Likewise, C is always expecting B. Phil @independentid www.independentid.com phil.h...@oracle.com On Mar 26, 2015, at 1:31 PM, Justin Richer jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been passed around. Note that service A or the Client can also request a downscoped token with [ C ] to call service C directly as well, and C doesn’t have to care how it got there. In other words, it lets the client software be very, very dumb. It doesn’t have to do any special processing, doesn’t have to know what’s in the token, it just follows the recipe of “I got a token, I get another token based on this to call someone else”. It’s also analogous to the refresh token flow, but with access tokens going in and out. I’ve deployed this setup several times in different service deployments. Even though there is a performance hit in the additional round trips (as Phil brought up in another thread), in these cases the desire to have the tokens hold least privilege access rights (smallest set of scopes per service) outweighed any performance hit (which was shown to be rather small in practice). What I want is for the token swap draft to define or use a mechanism that allows us to do this. I think we can do that pretty easily by adjusting the token swap syntax and language, and explicitly calling out the semantic processing portion (the current core of the document) for what it is: a way for a token issuer to communicate to a token service specific actions. At a high level, the spec would be something like: 1. How to swap a token at an AS 1. Send a request to the token endpoint with a new grant type, and a token (of any type/format/flavor) on the way in 2. Get back a new token in a token response 2. Communicating act as / on behalf of semantics via a JWT assertion 1. How to create (as an AS/RS/client/other issuer) a JWT with act-as semantics 2. What to do (as an AS/RS) with a JWT with act-as semantics 3. How to create a JWT with on-behalf-of semeantics 4. What to do with a JWT with on-behalf-of-semantics 5. How to possibly represent these semantics with something other than a JWT Section 2 uses the syntax from section 1. Other applications, like the one I laid out above, can use the syntax from section 1 as well. This works for structured, unstructured, self-generated, cross-domain, within-domain, and other tokens. — Justin ___ OAuth mailing list OAuth@ietf.org https://www.ietf.org/mailman/listinfo/oauth ___ OAuth mailing list OAuth@ietf.org https://www.ietf.org/mailman/listinfo/oauth
Re: [OAUTH-WG] Token Chaining Use Case
+1. We all have to change production code when non final specs evolve. I particularly don't see this as a valid argument at the start of a standards discussion. Phil On Mar 26, 2015, at 15:13, Bill Mills wmills_92...@yahoo.com wrote: By definition an access token is becoming a form of refresh token.The because my implementation didn't do it that way isn't convincing me. On Thursday, March 26, 2015 12:44 PM, Justin Richer jric...@mit.edu wrote: Because many implementations (including mine which does support my old token chaining draft) treat access tokens and refresh tokens separately in terms of data store and structure. Additionally, the refresh token is tied to the client and presented by the client. But in this case it's someone downstream, an RS, presenting the token. So unlike a refresh token being presented by the one it was issued to, this token is being presented by someone it was presented to. The feeling is close, but not quite the same in either development or assumptions. -- Justin / Sent from my phone / Original message From: Bill Mills wmills_92...@yahoo.com Date: 03/26/2015 2:24 PM (GMT-06:00) To: Justin Richer jric...@mit.edu, oauth@ietf.org oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case So why can't the access tokne simply be re-used as a refresh token? Why would it need a new grant type at all? On Thursday, March 26, 2015 11:31 AM, Justin Richer jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been passed around. Note that service A or the Client can also request a downscoped token with [ C ] to call service C directly as well, and C doesn’t have to care how it got there. In other words, it lets the client software be very, very dumb. It doesn’t have to do any special processing, doesn’t have to know what’s in the token, it just follows the recipe of “I got a token, I get another token based on this to call someone else”. It’s also analogous to the refresh token flow, but with access tokens going in and out. I’ve deployed this setup several times in different service deployments. Even though there is a performance hit in the additional round trips (as Phil brought up in another thread), in these cases the desire to have the tokens hold least privilege access rights (smallest set of scopes per service) outweighed any performance hit (which was shown to be rather small in practice). What I want is for the token swap draft to define or use a mechanism that allows us to do this. I think we can do that pretty easily by adjusting the token swap syntax and language, and explicitly calling out the semantic processing portion (the current core of the document) for what it is: a way for a token issuer to communicate to a token service specific actions. At a high level, the spec would be something like: 1. How to swap a token at an AS 1. Send a request to the token endpoint with a new grant type, and a token (of any type/format/flavor) on the way in 2. Get back a new token in a token response 2. Communicating act as / on behalf of semantics via a JWT assertion 1. How to create (as an AS/RS/client/other issuer) a JWT with act-as semantics 2. What to do (as an AS/RS) with a JWT with act-as semantics 3. How to create a JWT with on-behalf-of semeantics 4. What to do with a JWT with on-behalf-of-semantics 5. How to possibly represent these semantics with something other than a JWT Section 2 uses the syntax from section 1. Other applications, like the one I laid out above, can use the syntax from section 1 as well. This works for structured, unstructured, self-generated, cross-domain, within-domain,
Re: [OAUTH-WG] Token Chaining Use Case
So why can't the access tokne simply be re-used as a refresh token? Why would it need a new grant type at all? On Thursday, March 26, 2015 11:31 AM, Justin Richer jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been passed around. Note that service A or the Client can also request a downscoped token with [ C ] to call service C directly as well, and C doesn’t have to care how it got there. In other words, it lets the client software be very, very dumb. It doesn’t have to do any special processing, doesn’t have to know what’s in the token, it just follows the recipe of “I got a token, I get another token based on this to call someone else”. It’s also analogous to the refresh token flow, but with access tokens going in and out. I’ve deployed this setup several times in different service deployments. Even though there is a performance hit in the additional round trips (as Phil brought up in another thread), in these cases the desire to have the tokens hold least privilege access rights (smallest set of scopes per service) outweighed any performance hit (which was shown to be rather small in practice). What I want is for the token swap draft to define or use a mechanism that allows us to do this. I think we can do that pretty easily by adjusting the token swap syntax and language, and explicitly calling out the semantic processing portion (the current core of the document) for what it is: a way for a token issuer to communicate to a token service specific actions. At a high level, the spec would be something like: 1. How to swap a token at an AS 1. Send a request to the token endpoint with a new grant type, and a token (of any type/format/flavor) on the way in 2. Get back a new token in a token response 2. Communicating act as / on behalf of semantics via a JWT assertion 1. How to create (as an AS/RS/client/other issuer) a JWT with act-as semantics 2. What to do (as an AS/RS) with a JWT with act-as semantics 3. How to create a JWT with on-behalf-of semeantics 4. What to do with a JWT with on-behalf-of-semantics 5. How to possibly represent these semantics with something other than a JWT Section 2 uses the syntax from section 1. Other applications, like the one I laid out above, can use the syntax from section 1 as well. This works for structured, unstructured, self-generated, cross-domain, within-domain, and other tokens. — Justin ___ OAuth mailing list OAuth@ietf.org https://www.ietf.org/mailman/listinfo/oauth ___ OAuth mailing list OAuth@ietf.org https://www.ietf.org/mailman/listinfo/oauth
[OAUTH-WG] Token Chaining Use Case
As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been passed around. Note that service A or the Client can also request a downscoped token with [ C ] to call service C directly as well, and C doesn’t have to care how it got there. In other words, it lets the client software be very, very dumb. It doesn’t have to do any special processing, doesn’t have to know what’s in the token, it just follows the recipe of “I got a token, I get another token based on this to call someone else”. It’s also analogous to the refresh token flow, but with access tokens going in and out. I’ve deployed this setup several times in different service deployments. Even though there is a performance hit in the additional round trips (as Phil brought up in another thread), in these cases the desire to have the tokens hold least privilege access rights (smallest set of scopes per service) outweighed any performance hit (which was shown to be rather small in practice). What I want is for the token swap draft to define or use a mechanism that allows us to do this. I think we can do that pretty easily by adjusting the token swap syntax and language, and explicitly calling out the semantic processing portion (the current core of the document) for what it is: a way for a token issuer to communicate to a token service specific actions. At a high level, the spec would be something like: 1. How to swap a token at an AS 1. Send a request to the token endpoint with a new grant type, and a token (of any type/format/flavor) on the way in 2. Get back a new token in a token response 2. Communicating act as / on behalf of semantics via a JWT assertion 1. How to create (as an AS/RS/client/other issuer) a JWT with act-as semantics 2. What to do (as an AS/RS) with a JWT with act-as semantics 3. How to create a JWT with on-behalf-of semeantics 4. What to do with a JWT with on-behalf-of-semantics 5. How to possibly represent these semantics with something other than a JWT Section 2 uses the syntax from section 1. Other applications, like the one I laid out above, can use the syntax from section 1 as well. This works for structured, unstructured, self-generated, cross-domain, within-domain, and other tokens. — Justin signature.asc Description: Message signed with OpenPGP using GPGMail ___ OAuth mailing list OAuth@ietf.org https://www.ietf.org/mailman/listinfo/oauth
Re: [OAUTH-WG] Token Chaining Use Case
Hey Donald, I see your point. And yes, they are no really different. However, I think this is pretty much about refreshing tokens. I understand that in this case the refresh token is not presented by its owner but someone downstream. But you are kind of refreshing a previously issued token. And maybe using a specific grant_type when refreshing can help to handle this case differently considering all its particularities. Regards. Pedro Igor - Original Message - From: Donald F. Coffin donald.cof...@reminetworks.com To: Pedro Igor Silva psi...@redhat.com, Bill Mills wmills_92...@yahoo.com Cc: Phil Hunt phil.h...@oracle.com, oauth@ietf.org Sent: Thursday, March 26, 2015 6:29:41 PM Subject: RE: [OAUTH-WG] Token Chaining Use Case Pedro, Although the registry could be changed to support the new type format, how is that any different than adding a new grant_type, such as grant_type=token_swap or grant_type=swap? Best regards, Don Donald F. Coffin Founder/CTO REMI Networks 2335 Dunwoody Crossing Suite E Dunwoody, GA 30338-8221 Phone: (949) 636-8571 Email: donald.cof...@reminetworks.com -Original Message- From: Pedro Igor Silva [mailto:psi...@redhat.com] Sent: Thursday, March 26, 2015 5:25 PM To: Bill Mills Cc: Donald F. Coffin; Phil Hunt; oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case Couldn't be used a specific type of refresh_token ? Instead of using grant_type=refresh_token use a grant_type=urn:ietf:params:oauth:grant_type:redelegate (or something else) as an extension to refresh token flow ? Regards. Pedro Igor - Original Message - From: Bill Mills wmills_92...@yahoo.com To: Donald F. Coffin donald.cof...@reminetworks.com, Phil Hunt phil.h...@oracle.com Cc: oauth@ietf.org Sent: Thursday, March 26, 2015 6:13:05 PM Subject: Re: [OAUTH-WG] Token Chaining Use Case The RS calling back to the AS won't be confused, the token it gets would be it's refresh token. I don't see any reason why the AS can't be smart enough to know that a token that looks like an access token it issued is usable as a refresh token for limited purposes or downscoping. On Thursday, March 26, 2015 1:46 PM, Donald F. Coffin donald.cof...@reminetworks.com wrote: -1 Although Justin’s point might be a bit pre-mature as far as a standards discussion, the more critical reason IMHO is calling the AS’s /Token endpoint with a grant_type of “refresh_token” but providing an issued AT rather than an issued refresh_token (RT) will definitely create a backwards compatibility issue for many implementations. Best regards, Don Donald F. Coffin Founder/CTO REMI Networks 2335 Dunwoody Crossing Suite E Dunwoody, GA 30338-8221 Phone: (949) 636-8571 Email: donald.cof...@reminetworks.com From: Phil Hunt [mailto:phil.h...@oracle.com] Sent: Thursday, March 26, 2015 4:22 PM To: Bill Mills Cc: oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case +1. We all have to change production code when non final specs evolve. I particularly don't see this as a valid argument at the start of a standards discussion. Phil On Mar 26, 2015, at 15:13, Bill Mills wmills_92...@yahoo.com wrote: By definition an access token is becoming a form of refresh token. The because my implementation didn't do it that way isn't convincing me. On Thursday, March 26, 2015 12:44 PM, Justin Richer jric...@mit.edu wrote: Because many implementations (including mine which does support my old token chaining draft) treat access tokens and refresh tokens separately in terms of data store and structure. Additionally, the refresh token is tied to the client and presented by the client. But in this case it's someone downstream, an RS, presenting the token. So unlike a refresh token being presented by the one it was issued to, this token is being presented by someone it was presented to. The feeling is close, but not quite the same in either development or assumptions. -- Justin / Sent from my phone / Original message From: Bill Mills wmills_92...@yahoo.com Date: 03/26/2015 2:24 PM (GMT-06:00) To: Justin Richer jric...@mit.edu , oauth@ietf.org oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case So why can't the access tokne simply be re-used as a refresh token? Why would it need a new grant type at all? On Thursday, March 26, 2015 11:31 AM, Justin Richer jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and
Re: [OAUTH-WG] Token Chaining Use Case
Again, I don't think requiring a call out to an internal token reissuer is a
general solution. That said...
The RS calls the token endpoint treating the AT as a refresh token in all cases
and using the refresh_token grant type. Desired scope is specified by the RS.
It's not in spec if there are derivative internal scopes not in the original
scope list though. This doesn't support internal scopes for partitioning that
the AS doesn't know about.
An internal AS providing chaining would need to understand the AT just as the
RS does, and treat it as a refresh token.
-bill
On Thursday, March 26, 2015 2:22 PM, Donald F. Coffin
donald.cof...@reminetworks.com wrote:
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{margin-bottom:0in;}#yiv8232628268 Bill, Can you clarify your thoughts on the
following: · What AS endpoint does the RS call and how does it present
the AT he received?
· What is the grant_type value the RS use in the above endpoint request?
· What does the AS do if the AT was issued by another AS (which is
possible using Justin’s use case)? Best regards,DonDonald F. CoffinFounder/CTO
REMI Networks2335 Dunwoody Crossing Suite EDunwoody, GA 30338-8221 Phone:
(949) 636-8571Email: donald.cof...@reminetworks.com From: Bill Mills
[mailto:wmills_92...@yahoo.com]
Sent: Thursday, March 26, 2015 5:13 PM
To: Donald F. Coffin; 'Phil Hunt'
Cc: oauth@ietf.org
Subject: Re: [OAUTH-WG] Token Chaining Use Case The RS calling back to the AS
won't be confused, the token it gets would be it's refresh token. I don't see
any reason why the AS can't be smart enough to know that a token that looks
like an access token it issued is usable as a refresh token for limited
purposes or downscoping. On Thursday, March 26, 2015 1:46 PM, Donald F.
Coffin donald.cof...@reminetworks.com wrote: -1 Although Justin’s point
might be a bit pre-mature as far as a standards discussion, the more critical
Re: [OAUTH-WG] Token Chaining Use Case
Your service layout will determine whether or not each bit calls the same AS that issued the original token, since you can easily do it across boundaries if your AS takes in cross domain tokens. That’s another benefit of having it be a generic token swap, you can build it out using the same mechanism and get both behaviors. The AS could reject the swap for any number of conditions: wrong client asked, token is expired, scopes don’t align, bad token, etc. You can always optimize your system such that you just send a high-powered token down the chain, in which case you’re not using token swapping. This is not for those cases, obviously. This is for the cases when you *are* doing token swapping and usually downscoping the privileges. — Justin On Mar 26, 2015, at 2:53 PM, Phil Hunt phil.h...@oracle.com wrote: What if A calls be with it’s own authorization token (server token ST1) and passes AT1 in another header e.g. on-behalf-of. You save a call and can still check the scope downstream. Further, service B and C can each check whether ST1 and ST2 had the right to wield AT1 even when AT1’s POP proof is a proof of the external client. The only reason I can think to call the AS is if there is some dynamic condition that might cause an AS to reject the swap. If AT1 is valid, I can’t think of another reason why the answer isn’t already YES for all calls. If its no, its likely a permanent configuration problem not a dynamic decision. In other words, B always expects A to call it on behalf of some one. Likewise, C is always expecting B. Phil @independentid www.independentid.com phil.h...@oracle.com On Mar 26, 2015, at 1:31 PM, Justin Richer jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been passed around. Note that service A or the Client can also request a downscoped token with [ C ] to call service C directly as well, and C doesn’t have to care how it got there. In other words, it lets the client software be very, very dumb. It doesn’t have to do any special processing, doesn’t have to know what’s in the token, it just follows the recipe of “I got a token, I get another token based on this to call someone else”. It’s also analogous to the refresh token flow, but with access tokens going in and out. I’ve deployed this setup several times in different service deployments. Even though there is a performance hit in the additional round trips (as Phil brought up in another thread), in these cases the desire to have the tokens hold least privilege access rights (smallest set of scopes per service) outweighed any performance hit (which was shown to be rather small in practice). What I want is for the token swap draft to define or use a mechanism that allows us to do this. I think we can do that pretty easily by adjusting the token swap syntax and language, and explicitly calling out the semantic processing portion (the current core of the document) for what it is: a way for a token issuer to communicate to a token service specific actions. At a high level, the spec would be something like: 1. How to swap a token at an AS 1. Send a request to the token endpoint with a new grant type, and a token (of any type/format/flavor) on the way in 2. Get back a new token in a token response 2. Communicating act as / on behalf of semantics via a JWT assertion 1. How to create (as an AS/RS/client/other issuer) a JWT with act-as semantics 2. What to do (as an AS/RS) with a JWT with act-as semantics 3. How to create a JWT with on-behalf-of semeantics 4. What to do with a JWT with on-behalf-of-semantics 5. How to possibly represent these semantics with something other than a JWT Section 2 uses the syntax from
Re: [OAUTH-WG] Token Chaining Use Case
Requiring a round trip to the AS is going to have a huge headwind for implementation in high performance environments. I think we need to pursue something like what Phil is talking about where the intermediary server has it's own credential or authority. On Thursday, March 26, 2015 1:25 PM, Phil Hunt phil.h...@oracle.com wrote: See below Phil On Mar 26, 2015, at 15:15, Justin Richer jric...@mit.edu wrote: Your service layout will determine whether or not each bit calls the same AS that issued the original token, since you can easily do it across boundaries if your AS takes in cross domain tokens. That’s another benefit of having it be a generic token swap, you can build it out using the same mechanism and get both behaviors. The AS could reject the swap for any number of conditions: wrong client asked, token is expired, scopes don’t align, bad token, etc. You can always optimize your system such that you just send a high-powered token down the chain, in which case you’re not using token swapping. This is not for those cases, obviously. This is for the cases when you *are* doing token swapping and usually downscoping the privileges. There is no high power token in my new proposal. Each server must act on its own authority with its own token. The original at is passed as evidence of scoped authority to the internal services. There is no super token. — Justin On Mar 26, 2015, at 2:53 PM, Phil Hunt phil.h...@oracle.com wrote: What if A calls be with it’s own authorization token (server token ST1) and passes AT1 in another header e.g. on-behalf-of. You save a call and can still check the scope downstream. Further, service B and C can each check whether ST1 and ST2 had the right to wield AT1 even when AT1’s POP proof is a proof of the external client. The only reason I can think to call the AS is if there is some dynamic condition that might cause an AS to reject the swap. If AT1 is valid, I can’t think of another reason why the answer isn’t already YES for all calls. If its no, its likely a permanent configuration problem not a dynamic decision. In other words, B always expects A to call it on behalf of some one. Likewise, C is always expecting B. Phil @independentid www.independentid.com phil.h...@oracle.com On Mar 26, 2015, at 1:31 PM, Justin Richer jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been passed around. Note that service A or the Client can also request a downscoped token with [ C ] to call service C directly as well, and C doesn’t have to care how it got there. In other words, it lets the client software be very, very dumb. It doesn’t have to do any special processing, doesn’t have to know what’s in the token, it just follows the recipe of “I got a token, I get another token based on this to call someone else”. It’s also analogous to the refresh token flow, but with access tokens going in and out. I’ve deployed this setup several times in different service deployments. Even though there is a performance hit in the additional round trips (as Phil brought up in another thread), in these cases the desire to have the tokens hold least privilege access rights (smallest set of scopes per service) outweighed any performance hit (which was shown to be rather small in practice). What I want is for the token swap draft to define or use a mechanism that allows us to do this. I think we can do that pretty easily by adjusting the token swap syntax and language, and explicitly calling out the semantic processing portion (the current core of the document) for what it is: a way for a token issuer to communicate to a token service specific actions. At a high level,
Re: [OAUTH-WG] Token Chaining Use Case
This kind of token exchange might involve exchanges other than swapping an AT for another AT (and downscoping it). It might be an AT for a structured JWT specifically targeted at one of the the particular services that the original RS needs to call. Or an AT might be exchanged for a SAML assertion to use with legacy SOAP serveries. A good general token exchange mechanism enables lots of variations of cases like the one Justin mentioned. And more. In fact, I think downscoping might be a minority use case where what token exchange is often need for is translating tokens from what you have into what the resource you need to call can deal with. There need to be ways for the caller to tell the AS about the token it's asking for - by type or by the address/identifier of where it'll be used. There needs to be ways for the caller to authenticate to the AS. And there needs to be some way of expressing this delegation thing (though I'm still not totally convinced it couldn't be just the token is about the user/principal and the caller/client of the exchange is who is being delegated to). I realize few (approaching zero) people have or are going to read it but I have endeavored to cover all these things in the http://tools.ietf.org/html/draft-campbell-oauth-sts-02 draft. It's an early draft so not without it some rough edges but can provide some guidance on what is needed and offers some protocol syntax for expressing it. I believe Justin's use case would be covered by it (defining a specific token type URI for an OAuth access token issued by the AS in question might be needed) as are many others. On Thu, Mar 26, 2015 at 1:31 PM, Justin Richer jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been passed around. Note that service A or the Client can also request a downscoped token with [ C ] to call service C directly as well, and C doesn’t have to care how it got there. In other words, it lets the client software be very, very dumb. It doesn’t have to do any special processing, doesn’t have to know what’s in the token, it just follows the recipe of “I got a token, I get another token based on this to call someone else”. It’s also analogous to the refresh token flow, but with access tokens going in and out. I’ve deployed this setup several times in different service deployments. Even though there is a performance hit in the additional round trips (as Phil brought up in another thread), in these cases the desire to have the tokens hold least privilege access rights (smallest set of scopes per service) outweighed any performance hit (which was shown to be rather small in practice). What I want is for the token swap draft to define or use a mechanism that allows us to do this. I think we can do that pretty easily by adjusting the token swap syntax and language, and explicitly calling out the semantic processing portion (the current core of the document) for what it is: a way for a token issuer to communicate to a token service specific actions. At a high level, the spec would be something like: 1. How to swap a token at an AS 1. Send a request to the token endpoint with a new grant type, and a token (of any type/format/flavor) on the way in 2. Get back a new token in a token response 2. Communicating act as / on behalf of semantics via a JWT assertion 1. How to create (as an AS/RS/client/other issuer) a JWT with act-as semantics 2. What to do (as an AS/RS) with a JWT with act-as semantics 3. How to create a JWT with on-behalf-of semeantics 4. What to do with a JWT with on-behalf-of-semantics 5. How to possibly represent these semantics with something other than a JWT Section 2 uses the syntax from section 1. Other applications, like the one I laid out above, can use the
Re: [OAUTH-WG] Token Chaining Use Case
The RS calling back to the AS won't be confused, the token it gets would be
it's refresh token. I don't see any reason why the AS can't be smart enough to
know that a token that looks like an access token it issued is usable as a
refresh token for limited purposes or downscoping.
On Thursday, March 26, 2015 1:46 PM, Donald F. Coffin
donald.cof...@reminetworks.com wrote:
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div.yiv0625374937WordSection1 {}#yiv0625374937 -1 Although Justin’s point
might be a bit pre-mature as far as a standards discussion, the more critical
reason IMHO is calling the AS’s /Token endpoint with a grant_type of
“refresh_token” but providing an issued AT rather than an issued refresh_token
(RT) will definitely create a backwards compatibility issue for many
implementations. Best regards,DonDonald F. CoffinFounder/CTO REMI
Networks2335 Dunwoody Crossing Suite EDunwoody, GA 30338-8221 Phone:
(949) 636-8571Email: donald.cof...@reminetworks.com From: Phil Hunt
[mailto:phil.h...@oracle.com]
Sent: Thursday, March 26, 2015 4:22 PM
To: Bill Mills
Cc: oauth@ietf.org
Subject: Re: [OAUTH-WG] Token Chaining Use Case +1. We all have to change
production code when non final specs evolve. I particularly don't see this as
a valid argument at the start of a standards discussion.
Phil
On Mar 26, 2015, at 15:13, Bill Mills wmills_92...@yahoo.com wrote:
By definition an access token is becoming a form of refresh token. The
because my implementation didn't do it that way isn't convincing me. On
Thursday, March 26, 2015 12:44 PM, Justin Richer jric...@mit.edu wrote:
Because many implementations (including mine which does support my old token
chaining draft) treat access tokens and refresh tokens separately in terms of
data store and structure. Additionally, the refresh token is tied to the client
and presented by the client. But in this case it's someone downstream, an RS,
presenting the token. So unlike a refresh token being presented by the one it
was issued to, this token is being presented by someone it was presented to.
The feeling is close, but not quite the same in either development or
assumptions. -- Justin / Sent from my phone /
Original message
From: Bill Mills wmills_92...@yahoo.com
Date: 03/26/2015 2:24 PM (GMT-06:00)
To: Justin Richer jric...@mit.edu, oauth@ietf.org oauth@ietf.org
Subject: Re: [OAUTH-WG] Token Chaining Use Case So why can't the access tokne
simply be re-used as a refresh token? Why would it need a new grant type at
all? On Thursday, March 26, 2015 11:31 AM, Justin Richer jric...@mit.edu
wrote: As requested after last night’s informal meeting, here is the token
chaining use case that I want to see represented in the token swap draft.
[ Client ] - [ A ] - [ B ] - [ C ]
An OAuth client gets an access token AT1, just like it always would, with
scopes [A, B, C] in order to call service A, which requires all three scopes.
Service A (an RS) accepts this token since it has its scope, and then needs to
call service B in turn, which requires scopes [B, C]. It could just re-send the
token it got in, AT1, but that would give the downstream RS the ability to call
services with scope [ A ] and it should not be allowed to do that. To limit
exposure, service A calls a token swap at the AS to create AT2 with scopes [ B,
C ], effectively acting as an OAuth client requesting a downscoped token based
on AT1. Service A then acts as an OAuth client to call service B, now acting as
an RS to service A’s client, and can fulfill the request. And it’s turtles all
the way down: Service B can also call service C, and now B acts as a client,
requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C.
This prevents C from being able to call B or A, both of which would have been
available if AT1 had been passed around. Note that service A or the Client
Re: [OAUTH-WG] Token Chaining Use Case
Bill, Can you clarify your thoughts on the following: * What AS endpoint does the RS call and how does it present the AT he received? * What is the grant_type value the RS use in the above endpoint request? * What does the AS do if the AT was issued by another AS (which is possible using Justin’s use case)? Best regards, Don Donald F. Coffin Founder/CTO REMI Networks 2335 Dunwoody Crossing Suite E Dunwoody, GA 30338-8221 Phone: (949) 636-8571 Email:mailto:donald.cof...@reminetworks.com donald.cof...@reminetworks.com From: Bill Mills [mailto:wmills_92...@yahoo.com] Sent: Thursday, March 26, 2015 5:13 PM To: Donald F. Coffin; 'Phil Hunt' Cc: oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case The RS calling back to the AS won't be confused, the token it gets would be it's refresh token. I don't see any reason why the AS can't be smart enough to know that a token that looks like an access token it issued is usable as a refresh token for limited purposes or downscoping. On Thursday, March 26, 2015 1:46 PM, Donald F. Coffin donald.cof...@reminetworks.com mailto:donald.cof...@reminetworks.com wrote: -1 Although Justin’s point might be a bit pre-mature as far as a standards discussion, the more critical reason IMHO is calling the AS’s /Token endpoint with a grant_type of “refresh_token” but providing an issued AT rather than an issued refresh_token (RT) will definitely create a backwards compatibility issue for many implementations. Best regards, Don Donald F. Coffin Founder/CTO REMI Networks 2335 Dunwoody Crossing Suite E Dunwoody, GA 30338-8221 Phone: (949) 636-8571 Email:mailto:donald.cof...@reminetworks.com donald.cof...@reminetworks.com From: Phil Hunt [mailto:phil.h...@oracle.com] Sent: Thursday, March 26, 2015 4:22 PM To: Bill Mills Cc: oauth@ietf.org mailto:oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case +1. We all have to change production code when non final specs evolve. I particularly don't see this as a valid argument at the start of a standards discussion. Phil On Mar 26, 2015, at 15:13, Bill Mills wmills_92...@yahoo.com mailto:wmills_92...@yahoo.com wrote: By definition an access token is becoming a form of refresh token.The because my implementation didn't do it that way isn't convincing me. On Thursday, March 26, 2015 12:44 PM, Justin Richer jric...@mit.edu mailto:jric...@mit.edu wrote: Because many implementations (including mine which does support my old token chaining draft) treat access tokens and refresh tokens separately in terms of data store and structure. Additionally, the refresh token is tied to the client and presented by the client. But in this case it's someone downstream, an RS, presenting the token. So unlike a refresh token being presented by the one it was issued to, this token is being presented by someone it was presented to. The feeling is close, but not quite the same in either development or assumptions. -- Justin / Sent from my phone / Original message From: Bill Mills wmills_92...@yahoo.com mailto:wmills_92...@yahoo.com Date: 03/26/2015 2:24 PM (GMT-06:00) To: Justin Richer jric...@mit.edu mailto:jric...@mit.edu , oauth@ietf.org mailto:oauth@ietf.org oauth@ietf.org mailto:oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case So why can't the access tokne simply be re-used as a refresh token? Why would it need a new grant type at all? On Thursday, March 26, 2015 11:31 AM, Justin Richer jric...@mit.edu mailto:jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been passed around. Note that service A or the Client
Re: [OAUTH-WG] Token Chaining Use Case
Pedro, Although the registry could be changed to support the new type format, how is that any different than adding a new grant_type, such as grant_type=token_swap or grant_type=swap? Best regards, Don Donald F. Coffin Founder/CTO REMI Networks 2335 Dunwoody Crossing Suite E Dunwoody, GA 30338-8221 Phone: (949) 636-8571 Email: donald.cof...@reminetworks.com -Original Message- From: Pedro Igor Silva [mailto:psi...@redhat.com] Sent: Thursday, March 26, 2015 5:25 PM To: Bill Mills Cc: Donald F. Coffin; Phil Hunt; oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case Couldn't be used a specific type of refresh_token ? Instead of using grant_type=refresh_token use a grant_type=urn:ietf:params:oauth:grant_type:redelegate (or something else) as an extension to refresh token flow ? Regards. Pedro Igor - Original Message - From: Bill Mills wmills_92...@yahoo.com To: Donald F. Coffin donald.cof...@reminetworks.com, Phil Hunt phil.h...@oracle.com Cc: oauth@ietf.org Sent: Thursday, March 26, 2015 6:13:05 PM Subject: Re: [OAUTH-WG] Token Chaining Use Case The RS calling back to the AS won't be confused, the token it gets would be it's refresh token. I don't see any reason why the AS can't be smart enough to know that a token that looks like an access token it issued is usable as a refresh token for limited purposes or downscoping. On Thursday, March 26, 2015 1:46 PM, Donald F. Coffin donald.cof...@reminetworks.com wrote: -1 Although Justin’s point might be a bit pre-mature as far as a standards discussion, the more critical reason IMHO is calling the AS’s /Token endpoint with a grant_type of “refresh_token” but providing an issued AT rather than an issued refresh_token (RT) will definitely create a backwards compatibility issue for many implementations. Best regards, Don Donald F. Coffin Founder/CTO REMI Networks 2335 Dunwoody Crossing Suite E Dunwoody, GA 30338-8221 Phone: (949) 636-8571 Email: donald.cof...@reminetworks.com From: Phil Hunt [mailto:phil.h...@oracle.com] Sent: Thursday, March 26, 2015 4:22 PM To: Bill Mills Cc: oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case +1. We all have to change production code when non final specs evolve. I particularly don't see this as a valid argument at the start of a standards discussion. Phil On Mar 26, 2015, at 15:13, Bill Mills wmills_92...@yahoo.com wrote: By definition an access token is becoming a form of refresh token. The because my implementation didn't do it that way isn't convincing me. On Thursday, March 26, 2015 12:44 PM, Justin Richer jric...@mit.edu wrote: Because many implementations (including mine which does support my old token chaining draft) treat access tokens and refresh tokens separately in terms of data store and structure. Additionally, the refresh token is tied to the client and presented by the client. But in this case it's someone downstream, an RS, presenting the token. So unlike a refresh token being presented by the one it was issued to, this token is being presented by someone it was presented to. The feeling is close, but not quite the same in either development or assumptions. -- Justin / Sent from my phone / Original message From: Bill Mills wmills_92...@yahoo.com Date: 03/26/2015 2:24 PM (GMT-06:00) To: Justin Richer jric...@mit.edu , oauth@ietf.org oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case So why can't the access tokne simply be re-used as a refresh token? Why would it need a new grant type at all? On Thursday, March 26, 2015 11:31 AM, Justin Richer jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been
Re: [OAUTH-WG] Token Chaining Use Case
-1 Although Justin’s point might be a bit pre-mature as far as a standards discussion, the more critical reason IMHO is calling the AS’s /Token endpoint with a grant_type of “refresh_token” but providing an issued AT rather than an issued refresh_token (RT) will definitely create a backwards compatibility issue for many implementations. Best regards, Don Donald F. Coffin Founder/CTO REMI Networks 2335 Dunwoody Crossing Suite E Dunwoody, GA 30338-8221 Phone: (949) 636-8571 Email:mailto:donald.cof...@reminetworks.com donald.cof...@reminetworks.com From: Phil Hunt [mailto:phil.h...@oracle.com] Sent: Thursday, March 26, 2015 4:22 PM To: Bill Mills Cc: oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case +1. We all have to change production code when non final specs evolve. I particularly don't see this as a valid argument at the start of a standards discussion. Phil On Mar 26, 2015, at 15:13, Bill Mills wmills_92...@yahoo.com mailto:wmills_92...@yahoo.com wrote: By definition an access token is becoming a form of refresh token.The because my implementation didn't do it that way isn't convincing me. On Thursday, March 26, 2015 12:44 PM, Justin Richer jric...@mit.edu mailto:jric...@mit.edu wrote: Because many implementations (including mine which does support my old token chaining draft) treat access tokens and refresh tokens separately in terms of data store and structure. Additionally, the refresh token is tied to the client and presented by the client. But in this case it's someone downstream, an RS, presenting the token. So unlike a refresh token being presented by the one it was issued to, this token is being presented by someone it was presented to. The feeling is close, but not quite the same in either development or assumptions. -- Justin / Sent from my phone / Original message From: Bill Mills wmills_92...@yahoo.com mailto:wmills_92...@yahoo.com Date: 03/26/2015 2:24 PM (GMT-06:00) To: Justin Richer jric...@mit.edu mailto:jric...@mit.edu , oauth@ietf.org mailto:oauth@ietf.org oauth@ietf.org mailto:oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case So why can't the access tokne simply be re-used as a refresh token? Why would it need a new grant type at all? On Thursday, March 26, 2015 11:31 AM, Justin Richer jric...@mit.edu mailto:jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been passed around. Note that service A or the Client can also request a downscoped token with [ C ] to call service C directly as well, and C doesn’t have to care how it got there. In other words, it lets the client software be very, very dumb. It doesn’t have to do any special processing, doesn’t have to know what’s in the token, it just follows the recipe of “I got a token, I get another token based on this to call someone else”. It’s also analogous to the refresh token flow, but with access tokens going in and out. I’ve deployed this setup several times in different service deployments. Even though there is a performance hit in the additional round trips (as Phil brought up in another thread), in these cases the desire to have the tokens hold least privilege access rights (smallest set of scopes per service) outweighed any performance hit (which was shown to be rather small in practice). What I want is for the token swap draft to define or use a mechanism that allows us to do this. I think we can do that pretty easily by adjusting the token swap syntax and language, and explicitly calling out the semantic processing portion (the current core of the document) for what it is: a way for a token issuer to communicate to a token service specific actions. At a
Re: [OAUTH-WG] Token Chaining Use Case
Couldn't be used a specific type of refresh_token ? Instead of using grant_type=refresh_token use a grant_type=urn:ietf:params:oauth:grant_type:redelegate (or something else) as an extension to refresh token flow ? Regards. Pedro Igor - Original Message - From: Bill Mills wmills_92...@yahoo.com To: Donald F. Coffin donald.cof...@reminetworks.com, Phil Hunt phil.h...@oracle.com Cc: oauth@ietf.org Sent: Thursday, March 26, 2015 6:13:05 PM Subject: Re: [OAUTH-WG] Token Chaining Use Case The RS calling back to the AS won't be confused, the token it gets would be it's refresh token. I don't see any reason why the AS can't be smart enough to know that a token that looks like an access token it issued is usable as a refresh token for limited purposes or downscoping. On Thursday, March 26, 2015 1:46 PM, Donald F. Coffin donald.cof...@reminetworks.com wrote: -1 Although Justin’s point might be a bit pre-mature as far as a standards discussion, the more critical reason IMHO is calling the AS’s /Token endpoint with a grant_type of “refresh_token” but providing an issued AT rather than an issued refresh_token (RT) will definitely create a backwards compatibility issue for many implementations. Best regards, Don Donald F. Coffin Founder/CTO REMI Networks 2335 Dunwoody Crossing Suite E Dunwoody, GA 30338-8221 Phone: (949) 636-8571 Email: donald.cof...@reminetworks.com From: Phil Hunt [mailto:phil.h...@oracle.com] Sent: Thursday, March 26, 2015 4:22 PM To: Bill Mills Cc: oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case +1. We all have to change production code when non final specs evolve. I particularly don't see this as a valid argument at the start of a standards discussion. Phil On Mar 26, 2015, at 15:13, Bill Mills wmills_92...@yahoo.com wrote: By definition an access token is becoming a form of refresh token. The because my implementation didn't do it that way isn't convincing me. On Thursday, March 26, 2015 12:44 PM, Justin Richer jric...@mit.edu wrote: Because many implementations (including mine which does support my old token chaining draft) treat access tokens and refresh tokens separately in terms of data store and structure. Additionally, the refresh token is tied to the client and presented by the client. But in this case it's someone downstream, an RS, presenting the token. So unlike a refresh token being presented by the one it was issued to, this token is being presented by someone it was presented to. The feeling is close, but not quite the same in either development or assumptions. -- Justin / Sent from my phone / Original message From: Bill Mills wmills_92...@yahoo.com Date: 03/26/2015 2:24 PM (GMT-06:00) To: Justin Richer jric...@mit.edu , oauth@ietf.org oauth@ietf.org Subject: Re: [OAUTH-WG] Token Chaining Use Case So why can't the access tokne simply be re-used as a refresh token? Why would it need a new grant type at all? On Thursday, March 26, 2015 11:31 AM, Justin Richer jric...@mit.edu wrote: As requested after last night’s informal meeting, here is the token chaining use case that I want to see represented in the token swap draft. [ Client ] - [ A ] - [ B ] - [ C ] An OAuth client gets an access token AT1, just like it always would, with scopes [A, B, C] in order to call service A, which requires all three scopes. Service A (an RS) accepts this token since it has its scope, and then needs to call service B in turn, which requires scopes [B, C]. It could just re-send the token it got in, AT1, but that would give the downstream RS the ability to call services with scope [ A ] and it should not be allowed to do that. To limit exposure, service A calls a token swap at the AS to create AT2 with scopes [ B, C ], effectively acting as an OAuth client requesting a downscoped token based on AT1. Service A then acts as an OAuth client to call service B, now acting as an RS to service A’s client, and can fulfill the request. And it’s turtles all the way down: Service B can also call service C, and now B acts as a client, requesting AT3 with scope [ C ] based on AT2, and sending AT3 to service C. This prevents C from being able to call B or A, both of which would have been available if AT1 had been passed around. Note that service A or the Client can also request a downscoped token with [ C ] to call service C directly as well, and C doesn’t have to care how it got there. In other words, it lets the client software be very, very dumb. It doesn’t have to do any special processing, doesn’t have to know what’s in the token, it just follows the recipe of “I got a token, I get another token based on this to call someone else”. It’s also analogous to the refresh token flow, but with access tokens going in and out. I’ve deployed this setup several times in different service deployments. Even though there is a performance hit in the
[OAUTH-WG] Publication has been requested for draft-ietf-oauth-spop-10
Hannes Tschofenig has requested publication of draft-ietf-oauth-spop-10 as Proposed Standard on behalf of the OAUTH working group. Please verify the document's state at http://datatracker.ietf.org/doc/draft-ietf-oauth-spop/ ___ OAuth mailing list OAuth@ietf.org https://www.ietf.org/mailman/listinfo/oauth
Re: [OAUTH-WG] Token Chaining Use Case
AS already has the problem of checking requested scopes, this doesn't change
that.
In fact an AS could issue a new refresh token in return for the presented one
(which is the user/app AT) that's limited to be used by the RS as a client.
If one of the things we want is the ability to have the AS return N access
tokens, one for each scope allowing the RS to make a single round trip request
to the AS for all of the more limited scope tokens, then a new grant type is in
fact needed.
On Thursday, March 26, 2015 3:33 PM, Donald F. Coffin
donald.cof...@reminetworks.com wrote:
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div.yiv7149031579WordSection1 {}#yiv7149031579 Bill, Thanks for the
clarification. How do you propose the AS deal with the following RFC6749
Section 6. Refreshing an Access Token requirement? ScopeOPTIONAL. The scope
of the access request as described by Section 3.3. The requested scope MUST
NOT include any scope not originally granted by the resource owner, and if
omitted is
