<p></p>
<h3 dir="auto">URL</h3>
<p dir="auto"><em>No response</em></p>
<h3 dir="auto">How to reproduce the issue?</h3>
<h3 dir="auto">Reproduction</h3>
<ol dir="auto">
<li>
<p dir="auto">When making a an OAuth2 authorization request, omit the <code class="notranslate">redirect_uri</code>. E.g. open <a href="https://master.apis.dev.openstreetmap.org/oauth2/authorize?response_type=code&client_id=nOkiqW1fUHssu_e0Qbk6yLx7659s19CUx3nGmOP5JZk&scope=read_prefs" rel="nofollow">https://master.apis.dev.openstreetmap.org/oauth2/authorize?response_type=code&client_id=nOkiqW1fUHssu_e0Qbk6yLx7659s19CUx3nGmOP5JZk&scope=read_prefs</a> in the browser</p>
</li>
<li>
<p dir="auto">Authorization server responds with "The requested redirect uri is malformed or doesn't match client redirect URI."</p>
</li>
</ol>
<h2 dir="auto">Description</h2>
<p dir="auto">This does not seem to be compliant to <a href="https://datatracker.ietf.org/doc/html/rfc6749" rel="nofollow">RFC 6749 -  The OAuth 2.0 Authorization Framework</a>:</p>
<ul dir="auto">
<li>
<p dir="auto"><strong><a href="https://datatracker.ietf.org/doc/html/rfc6749#section-4.1.1" rel="nofollow">4.1.1</a>. Authorization Request</strong> lists <code class="notranslate">redirect_uri</code> as OPTIONAL</p>
</li>
<li>
<p dir="auto"><strong><a href="https://datatracker.ietf.org/doc/html/rfc6749#section-4.1.3" rel="nofollow">4.1.3</a>. Access Token Request</strong> lists <code class="notranslate">redirect_uri</code> only as REQUIRED if it was supplied in the authorization request</p>
</li>
<li>
<p dir="auto"><strong><a href="https://datatracker.ietf.org/doc/html/rfc6749#section-3.1.2.3" rel="nofollow">3.1.2.3</a>. Dynamic Configuration</strong> clarifies that only if no redirection URI has been registered for the client, a <code class="notranslate">redirect_uri</code> MUST be included in the authorization request. (<em>When</em> a<code class="notranslate">redirect_uri</code> is included in an authorization request, the authorization server MUST compare and match the value received against at least one of the registered redirection URIs)</p>
</li>
<li>
<p dir="auto"><strong><a href="https://datatracker.ietf.org/doc/html/rfc6749#section-3.1.2.2" rel="nofollow">3.1.2.2</a>.  Registration Requirements</strong> specifies that public clients MUST specify their redirect endpoint upon registration.</p>
<p dir="auto">In fact, OpenStreetMap currently enforces that <strong>any</strong> client, even confidential ones, have to specify (at least one) redirect uri upon registration:<br>
<a target="_blank" rel="noopener noreferrer" href="https://user-images.githubusercontent.com/4661658/284900353-fd42660b-926f-46dd-9754-45d3702274ce.png"><img src="https://user-images.githubusercontent.com/4661658/284900353-fd42660b-926f-46dd-9754-45d3702274ce.png" alt="image" style="max-width: 100%;"></a></p>
</li>
</ul>
<h3 dir="auto">Screenshot(s) or anything else?</h3>
<p dir="auto"><em>No response</em></p>

<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br />Reply to this email directly, <a href="https://github.com/openstreetmap/openstreetmap-website/issues/4363">view it on GitHub</a>, or <a href="https://github.com/notifications/unsubscribe-auth/AAK2OLLVIIDKAYOV6TGIHM3YFXUZFAVCNFSM6AAAAAA7WEPM62VHI2DSMVQWIX3LMV43ASLTON2WKOZSGAYDMMRSGQZDKNI">unsubscribe</a>.<br />You are receiving this because you are subscribed to this thread.<img src="https://github.com/notifications/beacon/AAK2OLKX4QC7OERLKLQXM5DYFXUZFA5CNFSM6AAAAAA7WEPM62WGG33NNVSW45C7OR4XAZNFJFZXG5LFVJRW63LNMVXHIX3JMTHHPFENP4.gif" height="1" width="1" alt="" /><span style="color: transparent; font-size: 0; display: none; visibility: hidden; overflow: hidden; opacity: 0; width: 0; height: 0; max-width: 0; max-height: 0; mso-hide: all">Message ID: <span><openstreetmap/openstreetmap-website/issues/4363</span><span>@</span><span>github</span><span>.</span><span>com></span></span></p>
<script type="application/ld+json">[
{
"@context": "http://schema.org",
"@type": "EmailMessage",
"potentialAction": {
"@type": "ViewAction",
"target": "https://github.com/openstreetmap/openstreetmap-website/issues/4363",
"url": "https://github.com/openstreetmap/openstreetmap-website/issues/4363",
"name": "View Issue"
},
"description": "View this Issue on GitHub",
"publisher": {
"@type": "Organization",
"name": "GitHub",
"url": "https://github.com"
}
}
]</script>