Re: [OAUTH-WG] Can the repeated authorization of scopes be avoided ?
William Denniss <wdenniss@google.com> Tue, 19 January 2016 03:10 UTC
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From: William Denniss <wdenniss@google.com>
Date: Mon, 18 Jan 2016 19:10:15 -0800
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To: Sergey Beryozkin <sberyozkin@gmail.com>
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Subject: Re: [OAUTH-WG] Can the repeated authorization of scopes be avoided ?
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Agree with Justin, this is pretty common. We support it for re-auth as well as incremental auth (where the user has already approved scope "a" and is presented with a request for scopes "a b", they will only need to approve scope "b"). In fact if you don't do this, then incremental auth isn't really viable. Regarding security: don't do this for non-confidential clients where you can't verify the identity of the app by the redirect (e.g. a localhost redirect to an installed app). On Mon, Jan 18, 2016 at 4:44 AM, Sergey Beryozkin <sberyozkin@gmail.com> wrote: > Hi Justin, thanks for the advice, > > Cheers, Sergey > > On 18/01/16 11:47, Justin Richer wrote: > >> Yes, this is common practice. Give the user the option to remember the >> decision. This is known as "trust on first use", or tofu. Our server, >> MITREid Connect, implements this as do many others. >> >> >> >> -- Justin >> >> / Sent from my phone / >> >> >> -------- Original message -------- >> From: Sergey Beryozkin <sberyozkin@gmail.com> >> Date: 1/18/2016 5:59 AM (GMT-05:00) >> To: oauth@ietf.org >> Subject: [OAUTH-WG] Can the repeated authorization of scopes be avoided ? >> >> Hi All >> >> The question relates to the process of showing the authorization >> code/implicit flow consent screen to a user. >> >> >> I'm discussing with my colleagues the possibility of avoiding asking the >> same user whose session has expired and who is re-authenticating with AS >> which scopes should be approved. >> >> For example, suppose the OAuth2 client redirects a user with the >> requested scope 'a'. The user signs in to AS and is shown a consent >> screen asking to approve the 'a' scope. The user approves 'a' and the >> flow continues. >> >> Some time later, when the user's session has expired, the user is >> redirected to AS with the same 'a' scope. >> >> Would it be a good idea, at this point, not to show the user the consent >> screen asking to approve the 'a' scope again ? For example, AS can >> persist the fact that a given user has already approved 'a' for a given >> client earlier, so when the user re-authenticates, AS will use this info >> and will avoid showing the consent screen. >> >> That seems to make sense, but I'm wondering, can there be some security >> implications associated with it, any recommendations/advices will be >> welcome >> >> Sergey >> >> _______________________________________________ >> 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] Can the repeated authorization of scop… Sergey Beryozkin
- Re: [OAUTH-WG] Can the repeated authorization of … Justin Richer
- Re: [OAUTH-WG] Can the repeated authorization of … Sergey Beryozkin
- Re: [OAUTH-WG] Can the repeated authorization of … William Denniss
- Re: [OAUTH-WG] Can the repeated authorization of … Sergey Beryozkin
- Re: [OAUTH-WG] Can the repeated authorization of … Sergey Beryozkin
- Re: [OAUTH-WG] Can the repeated authorization of … John Bradley
- Re: [OAUTH-WG] Can the repeated authorization of … Thomas Broyer
- Re: [OAUTH-WG] Can the repeated authorization of … Justin Richer
- Re: [OAUTH-WG] Can the repeated authorization of … Sergey Beryozkin
- Re: [OAUTH-WG] Can the repeated authorization of … Thomas Broyer
- Re: [OAUTH-WG] Can the repeated authorization of … Sergey Beryozkin
- Re: [OAUTH-WG] Can the repeated authorization of … George Fletcher
- Re: [OAUTH-WG] Can the repeated authorization of … Thomas Broyer
- Re: [OAUTH-WG] Can the repeated authorization of … George Fletcher
- Re: [OAUTH-WG] Can the repeated authorization of … George Fletcher
- Re: [OAUTH-WG] Can the repeated authorization of … Sergey Beryozkin
- Re: [OAUTH-WG] Can the repeated authorization of … William Denniss
- Re: [OAUTH-WG] Can the repeated authorization of … Sergey Beryozkin
- Re: [OAUTH-WG] Can the repeated authorization of … John Bradley
- Re: [OAUTH-WG] Can the repeated authorization of … John Bradley