|
| 1 | +--- |
| 2 | +title: "Related Origin Requests" |
| 3 | +description: "The Related Origin Requests (ROR)feature allows an RP to enable a passkey to be created and used across a limited set of related origins." |
| 4 | +lead: "The Related Origin Requests (ROR) feature allows an RP to enable a passkey to be created and used across a limited set of related origins." |
| 5 | +date: 2024-08-22T15:20:51.937Z |
| 6 | +draft: false |
| 7 | +images: [] |
| 8 | +menu: |
| 9 | + docs: |
| 10 | + parent: "advanced" |
| 11 | +weight: 510 |
| 12 | +toc: true |
| 13 | +--- |
| 14 | + |
| 15 | +## Use Cases |
| 16 | + |
| 17 | +The two use cases for Related Origin Requests (ROR) are deployments which use different country code top-level domains (ccTLD) across the world, and deployments where different branding is used for different services. |
| 18 | + |
| 19 | +To address these use cases, it is recommended to leverage industry-standard federation protocols such as [OpenID Connect](https://openid.net/specs/openid-connect-core-1_0.html). This approach facilitates a centralized login experience, by using a dedicated login page (e.g., login.example.com) that serves as the authentication point for all origins and services. |
| 20 | + |
| 21 | +<strong>ROR is designed to be used when federation is <i>not</i> possible.</strong> |
| 22 | + |
| 23 | +{{< callout context="note" title="Websites vs Apps" icon="outline/note" >}} ROR is a WebAuthn feature for the web. App platforms have existing mechanisms for mapping native apps to one or more web origins: [Digital Asset Links](https://developers.google.com/identity/credential-sharing/set-up) for Android and [Associated Domains](https://developer.apple.com/documentation/xcode/supporting-associated-domains) on Apple platforms. {{< /callout >}} |
| 24 | + |
| 25 | +### Country Code Top Level Domains (ccTLDs) {#cctld} |
| 26 | + |
| 27 | +Many global organizations utilize [country code top level domains (ccTLDs)](https://icannwiki.org/Country_code_top-level_domain#Current_ccTLDs) to cater to their international services. For instance, a shopping website might use `shopping.com` for users in the United States, while also having `shopping.ca` for Canada, `shopping.co.uk` for the United Kingdom, `shopping.ie` for Ireland, and `shopping.sg` for Singapore, among others. However, a passkey created on `shopping.com` can't be used on `shopping.sg`, and vice versa. |
| 28 | + |
| 29 | +### Alternate Branding |
| 30 | + |
| 31 | +Some organizations offer additional services with different or extended branding and share the same accounts. For instance, a shopping site might have their own credit card or their own travel services, which are accessed via different websites. |
| 32 | + |
| 33 | +## How It Works |
| 34 | + |
| 35 | +Related Origin Requests (ROR) works by allowing a Relying Party (RP) to provide a list of valid origins for a given Relying Party ID (RP ID). |
| 36 | + |
| 37 | +During a WebAuthn ceremony, if the RP ID and origin do not match, the WebAuthn client can query the RP for a list of valid origins. The client processes that origin list and then re-evaluates the binding based on this additional context. If an origin is matched, the client will continue with the request in the context of the RP ID. |
| 38 | + |
| 39 | +A label, in the context of this feature, is the name directly preceding the [effective top level domain](https://developer.mozilla.org/en-US/docs/Glossary/eTLD). For instance, `shopping` is the label for `https://shopping.com`, `https://shopping.co.uk`, `https://shopping.co.jp`, `https://shopping.net`, and `https://shopping.org`. Labels are used as a way to support the large number of entries required to support [ccTLDs](#cctld), while enabling clients to restrict the number of unique origins to prevent abuse. |
| 40 | + |
| 41 | +If there are 30 origins in the list, all with the same label, these count as 1 unique label. WebAuthn requires client implementations to support at least 5 unique labels, however there are no known clients which support more than 5, so that should be treated as the maximum for deployments. |
| 42 | + |
| 43 | +Below are three examples of origin lists and their respective label counts. |
| 44 | + |
| 45 | +{{< tabs "label-examples" >}} |
| 46 | +{{< tab "1 Label" >}} |
| 47 | + |
| 48 | +1. `shopping` |
| 49 | + |
| 50 | +```json |
| 51 | +{ |
| 52 | + "origins": [ |
| 53 | + "https://shopping.com", |
| 54 | + "https://shopping.co.uk", |
| 55 | + "https://shopping.co.jp", |
| 56 | + "https://shopping.ie", |
| 57 | + "https://shopping.ca", |
| 58 | + "https://shopping.net", |
| 59 | + "https://shopping.org", |
| 60 | + "https://shopping.github.io" |
| 61 | + ] |
| 62 | +} |
| 63 | +``` |
| 64 | + |
| 65 | +{{< /tab >}} |
| 66 | +{{< tab "3 Labels" >}} |
| 67 | + |
| 68 | +1. `shopping` |
| 69 | +1. `myshoppingrewards` |
| 70 | +1. `myshoppingtravel` |
| 71 | + |
| 72 | +```json |
| 73 | +{ |
| 74 | + "origins": [ |
| 75 | + "https://shopping.com", |
| 76 | + "https://shopping.co.uk", |
| 77 | + "https://shopping.co.jp", |
| 78 | + "https://shopping.ie", |
| 79 | + "https://shopping.ca", |
| 80 | + "https://myshoppingrewards.com", |
| 81 | + "https://myshoppingrewards.co.uk", |
| 82 | + "https://myshoppingrewards.co.jp", |
| 83 | + "https://myshoppingrewards.ie", |
| 84 | + "https://myshoppingrewards.ca", |
| 85 | + "https://myshoppingtravel.com", |
| 86 | + "https://myshoppingtravel.co.uk", |
| 87 | + "https://myshoppingtravel.co.jp", |
| 88 | + "https://myshoppingtravel.ie", |
| 89 | + "https://myshoppingtravel.ca" |
| 90 | + ] |
| 91 | +} |
| 92 | +``` |
| 93 | + |
| 94 | +{{< /tab >}} |
| 95 | +{{< tab "5 Labels" >}} |
| 96 | + |
| 97 | +1. `shopping` |
| 98 | +1. `myshoppingcard` |
| 99 | +1. `myshoppingrewards` |
| 100 | +1. `myshoppingcreditcard` |
| 101 | +1. `myshoppingtravel` |
| 102 | + |
| 103 | +```json |
| 104 | +{ |
| 105 | + "origins": [ |
| 106 | + "https://shopping.com", |
| 107 | + "https://shopping.co.uk", |
| 108 | + "https://shopping.co.jp", |
| 109 | + "https://shopping.ie", |
| 110 | + "https://shopping.ca", |
| 111 | + "https://myshoppingcard.us", |
| 112 | + "https://myshoppingrewards.com", |
| 113 | + "https://myshoppingrewards.co.uk", |
| 114 | + "https://myshoppingrewards.co.jp", |
| 115 | + "https://myshoppingrewards.ie", |
| 116 | + "https://myshoppingrewards.ca", |
| 117 | + "https://myshoppingcreditcard.co.uk", |
| 118 | + "https://myshoppingcreditcard.co.jp", |
| 119 | + "https://myshoppingcreditcard.ie", |
| 120 | + "https://myshoppingcreditcard.ca", |
| 121 | + "https://myshoppingtravel.com", |
| 122 | + "https://myshoppingtravel.co.uk", |
| 123 | + "https://myshoppingtravel.co.jp", |
| 124 | + "https://myshoppingtravel.ie", |
| 125 | + "https://myshoppingtravel.ca" |
| 126 | + ] |
| 127 | +} |
| 128 | +``` |
| 129 | + |
| 130 | +{{< /tab >}} |
| 131 | +{{< /tabs >}} |
| 132 | + |
| 133 | +## Requirements |
| 134 | + |
| 135 | +### Client Support |
| 136 | + |
| 137 | +The [Device Support matrix](/device-support/#ror) lists the browsers which support Related Origin Requests. The [Passkeys Feature Detect page](https://featuredetect.passkeys.dev) will also attempt to detect ROR support in the browser in which the page was loaded. |
| 138 | + |
| 139 | +To dynamically detect support for Related Origin Requests on an enrollment or login page, Relying Parties should check for `relatedOrigins` in the [WebAuthn Get Client Capabilities (`PublicKeyCredential.getClientCapabilities()`)](https://w3c.github.io/webauthn/#sctn-getClientCapabilities) response. |
| 140 | + |
| 141 | +### Relying Party Changes |
| 142 | + |
| 143 | +A JSON document must be hosted at the WebAuthn well-known path for the Relying Party ID, `/.well-known/webauthn`. |
| 144 | + |
| 145 | +For example, if the RP ID is `shopping.com`, the full URL would be `https://shopping.com/.well-known/webauthn`. |
| 146 | + |
| 147 | +The server must respond with a content type of `application/json`. |
| 148 | + |
| 149 | +The JSON document must have a member named `origins`, containing an array of valid origins for use with passkeys scoped for the RP ID. |
| 150 | + |
| 151 | +> See [Deployment Considerations](#deployment-considerations) below for details on choosing an RP ID. |
| 152 | +
|
| 153 | +Below is an example for the RP ID `shopping.com`. |
| 154 | + |
| 155 | +```json {title="https://shopping.com/.well-known/webauthn"} |
| 156 | +{ |
| 157 | + "origins": [ |
| 158 | + "https://shopping.com", |
| 159 | + "https://myshoppingrewards.com", |
| 160 | + "https://myshoppingcreditcard.com", |
| 161 | + "https://myshoppingtravel.com", |
| 162 | + "https://shopping.co.uk", |
| 163 | + "https://shopping.co.jp", |
| 164 | + "https://shopping.ie", |
| 165 | + "https://shopping.ca" |
| 166 | + ] |
| 167 | +} |
| 168 | +``` |
| 169 | + |
| 170 | +## Deployment Considerations |
| 171 | + |
| 172 | +### Greenfield Deployments |
| 173 | + |
| 174 | +The most important design decision for a greenfield deployment using ROR is picking a common Relying Party ID (RP ID) to be used for passkeys across all origins. All WebAuthn requests across all related origins will use that as `rp.id`. |
| 175 | + |
| 176 | +It is recommended to pick the most commonly used and/or understood domain for the common RP ID. This is typically the domain closely associated with the organization's brand, and is often the `.com`. |
| 177 | + |
| 178 | +### Existing Deployments |
| 179 | + |
| 180 | +For deployments where passkeys are already rolled out with multiple RP IDs, there are some unique considerations and requirements. |
| 181 | + |
| 182 | +__Considerations__ |
| 183 | + |
| 184 | +- Users with a passkey for the "local" RP ID / origin will be able to use all passkeys experiences as normal. |
| 185 | +- Users with a passkey for another RP ID / related origin, will require an identifier first flow and a backend lookup. |
| 186 | + |
| 187 | +__Requirements__ |
| 188 | + |
| 189 | +- Each existing RP ID will need to host the WebAuthn well-known document, with all of the other origins listed in it. This will allow reciprocal use of passkeys |
| 190 | +- The account database will need to know which RP ID was used for each passkey (this could be an explicit property or inferred based on other data) |
| 191 | +- The username field on the login page will need to support fallback to an identifier first flow with backend lookup |
| 192 | + |
| 193 | +#### Flow |
| 194 | + |
| 195 | +This flow assumes the [autofill UI](/docs/reference/terms/#autofill-ui) for passkeys is being used. |
| 196 | + |
| 197 | +1. Make a conditional WebAuthn request normally on page load |
| 198 | +2. If the promise resolves, process the WebAuthn response as normal and sign the user in |
| 199 | +3. If the the user enters a username and continues: |
| 200 | + - abort the conditional WebAuthn request |
| 201 | + - send a request to your backend to retrieve the RP ID for the username |
| 202 | +4. Fetch fresh WebAuthn parameters from the backend |
| 203 | +5. Call WebAuthn with the fresh parameters and the correct RP ID |
| 204 | + |
| 205 | +#### Example |
| 206 | + |
| 207 | +In this example, passkeys have previously been rolled out to the following users: |
| 208 | + |
| 209 | +- `https://shopping.com` users, with an RP ID of `shopping.com` |
| 210 | +- `https://shopping.co.uk` users, with an RP ID or `shopping.co.uk` |
| 211 | + |
| 212 | +A user with a passkey for `shopping.com` navigates to `https://shopping.com`, clicks into the username field, selects their passkey, performs user verification, and is then signed in! |
| 213 | + |
| 214 | +A user with a passkey for `shopping.co.uk` has traveled to the US and navigates to `https://shopping.co.uk`. Based on location data, the user is redirected to `https://shopping.com`. They click into the username field and do not see any passkey available. They then type their username and click continue. A backend lookup occurs, and WebAuthn is now invoked with an RP ID of `shopping.co.uk` and the user selects their passkey, performs user verification, and is signed in! |
| 215 | + |
| 216 | +## Additional Information |
| 217 | + |
| 218 | +<a href="https://w3c.github.io/webauthn/#sctn-related-origins" target="_blank"><button type="button" class="btn btn-light">WebAuthn Spec Reference {{< icon-external-link size=24 >}}</button></a> |
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