While many W3C specifications are directed primarily to user agent developers and also to web application developers (i.e., "Web authors"), the nature of Web Authentication requires that this specification be correctly used by multiple audiences, as described below. All audiences ought to begin with §1.2 Use Cases, §12 Sample Scenarios, and §4 Terminology, and should also refer to [WebAuthnAPIGuide] for an overall tutorial.

Note: Along with the Web Authentication API itself, this specification defines a request-response cryptographic protocol between a WebAuthn Relying Party server and an authenticator, where the Relying Party's request consists of a challenge and other input data supplied by the Relying Party and sent to the authenticator. The request is conveyed via the combination of HTTPS, the Relying Party web application, the WebAuthn API, and the platform-specific communications channel between the user agent and the authenticator. The authenticator replies with a digitally signed authenticator data message and other output data, which is conveyed back to the Relying Party server via the same path in reverse. Protocol details vary according to whether an authentication or registration operation is invoked by the Relying Party. See also Figure 1 and Figure 2.

It is important for Web Authentication deployments' end-to-end security that the role of each component—the Relying Party server, the client, and the authenticator— as well as §13 Security Considerations and §14 Privacy Considerations, are understood by all audiences.

PublicKeyCredential's interface object's implementation of the [[Create]](origin, options, sameOriginWithAncestors) internal method [CREDENTIAL-MANAGEMENT-1] allows WebAuthn Relying Party scripts to call navigator.credentials.create() to request the creation of a new public key credential source, bound to an authenticator. This navigator.credentials.create() operation can be aborted by leveraging the AbortController; see DOM §3.3 Using AbortController and AbortSignal objects in APIs for detailed instructions.

This internal method accepts three arguments:

origin

This argument is the relevant settings object's origin, as determined by the calling create() implementation.

options

This argument is a CredentialCreationOptions object whose options.publicKey member contains a PublicKeyCredentialCreationOptions object specifying the desired attributes of the to-be-created public key credential.

sameOriginWithAncestors

This argument is a Boolean value which is true if and only if the caller’s environment settings object is same-origin with its ancestors.

Note: This algorithm is synchronous: the Promise resolution/rejection is handled by navigator.credentials.create().

Note: All BufferSource objects used in this algorithm must be snapshotted when the algorithm begins, to avoid potential synchronization issues. The algorithm implementations should get a copy of the bytes held by the buffer source and use that copy for relevant portions of the algorithm.

When this method is invoked, the user agent MUST execute the following algorithm:

1. Assert: options.publicKey is present.

2. If sameOriginWithAncestors is false, return a "NotAllowedError" DOMException.

   Note: This "sameOriginWithAncestors" restriction aims to address the concern raised in the Origin Confusion section of [CREDENTIAL-MANAGEMENT-1], while allowing Relying Party script access to Web Authentication functionality, e.g., when running in a secure context framed document that is same-origin with its ancestors. However, in the future, this specification (in conjunction with [CREDENTIAL-MANAGEMENT-1]) may provide Relying Parties with more fine-grained control--e.g., ranging from allowing only top-level access to Web Authentication functionality, to allowing cross-origin embedded cases--by leveraging [Feature-Policy] once the latter specification becomes stably implemented in user agents.

3. Let options be the value of options.publicKey.

4. If the timeout member of options is present, check if its value lies within a reasonable range as defined by the client and if not, correct it to the closest value lying within that range. Set a timer lifetimeTimer to this adjusted value. If the timeout member of options is not present, then set lifetimeTimer to a client-specific default.

   Note: A suggested reasonable range for the timeout member of options is 15 seconds to 120 seconds.

   Note: The user agent should take cognitive guidelines into considerations regarding timeout for users with special needs.

5. Let callerOrigin be origin. If callerOrigin is an opaque origin, return a DOMException whose name is "NotAllowedError", and terminate this algorithm.

6. Let effectiveDomain be the callerOrigin’s effective domain. If effective domain is not a valid domain, then return a DOMException whose name is "SecurityError" and terminate this algorithm.

   Note: An effective domain may resolve to a host, which can be represented in various manners, such as domain, ipv4 address, ipv6 address, opaque host, or empty host. Only the domain format of host is allowed here. This is for simplification and also is in recognition of various issues with using direct IP address identification in concert with PKI-based security.

7. If options.rp.id

   Is present

   If options.rp.id is not a registrable domain suffix of and is not equal to effectiveDomain, return a DOMException whose name is "SecurityError", and terminate this algorithm.

   Is not present

   Set options.rp.id to effectiveDomain.

   Note: options.rp.id represents the caller’s RP ID. The RP ID defaults to being the caller’s origin's effective domain unless the caller has explicitly set options.rp.id when calling create().

8. Let credTypesAndPubKeyAlgs be a new list whose items are pairs of PublicKeyCredentialType and a COSEAlgorithmIdentifier.

9. For each current of options.pubKeyCredParams:

   1. If current.type does not contain a PublicKeyCredentialType supported by this implementation, then continue.

   2. Let alg be current.alg.

   3. Append the pair of current.type and alg to credTypesAndPubKeyAlgs.

10. If credTypesAndPubKeyAlgs is empty and options.pubKeyCredParams is not empty, return a DOMException whose name is "NotSupportedError", and terminate this algorithm.

11. Let clientExtensions be a new map and let authenticatorExtensions be a new map.

12. If the extensions member of options is present, then for each extensionId → clientExtensionInput of options.extensions:

    1. If extensionId is not supported by this client platform or is not a registration extension, then continue.

    2. Set clientExtensions[extensionId] to clientExtensionInput.

    3. If extensionId is not an authenticator extension, then continue.

    4. Let authenticatorExtensionInput be the (CBOR) result of running extensionId’s client extension processing algorithm on clientExtensionInput. If the algorithm returned an error, continue.

    5. Set authenticatorExtensions[extensionId] to the base64url encoding of authenticatorExtensionInput.

13. Let collectedClientData be a new CollectedClientData instance whose fields are:

    type

    The string "webauthn.create".

    challenge

    The base64url encoding of options.challenge.

    origin

    The serialization of callerOrigin.

    tokenBinding

    The status of Token Binding between the client and the callerOrigin, as well as the Token Binding ID associated with callerOrigin, if one is available.

14. Let clientDataJSON be the JSON-serialized client data constructed from collectedClientData.

15. Let clientDataHash be the hash of the serialized client data represented by clientDataJSON.

16. If the options.signal is present and its aborted flag is set to true, return a DOMException whose name is "AbortError" and terminate this algorithm.

17. Let issuedRequests be a new ordered set.

18. Let authenticators represent a value which at any given instant is a set of client platform-specific handles, where each item identifies an authenticator presently available on this client platform at that instant.

    Note: What qualifies an authenticator as "available" is intentionally unspecified; this is meant to represent how authenticators can be hot-plugged into (e.g., via USB) or discovered (e.g., via NFC or Bluetooth) by the client by various mechanisms, or permanently built into the client.

19. Start lifetimeTimer.

20. While lifetimeTimer has not expired, perform the following actions depending upon lifetimeTimer, and the state and response for each authenticator in authenticators:

    If lifetimeTimer expires,

    For each authenticator in issuedRequests invoke the authenticatorCancel operation on authenticator and remove authenticator from issuedRequests.

    If the user exercises a user agent user-interface option to cancel the process,

    For each authenticator in issuedRequests invoke the authenticatorCancel operation on authenticator and remove authenticator from issuedRequests. Return a DOMException whose name is "NotAllowedError".

    If the options.signal is present and its aborted flag is set to true,

    For each authenticator in issuedRequests invoke the authenticatorCancel operation on authenticator and remove authenticator from issuedRequests. Then return a DOMException whose name is "AbortError" and terminate this algorithm.

    If an authenticator becomes available on this client device,

    Note: This includes the case where an authenticator was available upon lifetimeTimer initiation.

    1. If options.authenticatorSelection is present:

       1. If options.authenticatorSelection.authenticatorAttachment is present and its value is not equal to authenticator’s authenticator attachment modality, continue.

       2. If options.authenticatorSelection.requireResidentKey is set to true and the authenticator is not capable of storing a client-side-resident public key credential source, continue.

       3. If options.authenticatorSelection.userVerification is set to required and the authenticator is not capable of performing user verification, continue.

    2. Let userVerification be the effective user verification requirement for credential creation , a Boolean value, as follows. If options.authenticatorSelection.userVerification

       is set to required

       Let userVerification be true.

       is set to preferred

       If the authenticator

       is capable of user verification

       Let userVerification be true.

       is not capable of user verification

       Let userVerification be false.

       is set to discouraged

       Let userVerification be false.

    3. Let userPresence be a Boolean value set to the inverse of userVerification.

    4. Let excludeCredentialDescriptorList be a new list.

    5. For each credential descriptor C in options.excludeCredentials:

       1. If C.transports is not empty, and authenticator is connected over a transport not mentioned in C.transports, the client MAY continue.

       2. Otherwise, Append C to excludeCredentialDescriptorList.

    6. Invoke the authenticatorMakeCredential operation on authenticator with clientDataHash, options.rp, options.user, options.authenticatorSelection.requireResidentKey, userPresence, userVerification, credTypesAndPubKeyAlgs, excludeCredentialDescriptorList, and authenticatorExtensions as parameters.

    7. Append authenticator to issuedRequests.

    If an authenticator ceases to be available on this client device,

    Remove authenticator from issuedRequests.

    If any authenticator returns a status indicating that the user cancelled the operation,

    1. Remove authenticator from issuedRequests.

    2. For each remaining authenticator in issuedRequests invoke the authenticatorCancel operation on authenticator and remove it from issuedRequests.

       Note: Authenticators may return an indication of "the user cancelled the entire operation". How a user agent manifests this state to users is unspecified.

    If any authenticator returns an error status equivalent to "InvalidStateError",

    1. Remove authenticator from issuedRequests.

    2. For each remaining authenticator in issuedRequests invoke the authenticatorCancel operation on authenticator and remove it from issuedRequests.

    3. Return a DOMException whose name is "InvalidStateError" and terminate this algorithm.

    Note: This error status is handled separately because the authenticator returns it only if excludeCredentialDescriptorList identifies a credential bound to the authenticator and the user has consented to the operation. Given this explicit consent, it is acceptable for this case to be distinguishable to the Relying Party.

    If any authenticator returns an error status not equivalent to "InvalidStateError",

    Remove authenticator from issuedRequests.

    Note: This case does not imply user consent for the operation, so details about the error are hidden from the Relying Party in order to prevent leak of potentially identifying information. See §14.5 Registration Ceremony Privacy for details.

    If any authenticator indicates success,

    1. Remove authenticator from issuedRequests.

    2. Let credentialCreationData be a struct whose items are:

       attestationObjectResult

       whose value is the bytes returned from the successful authenticatorMakeCredential operation.

       Note: this value is attObj, as defined in §6.4.4 Generating an Attestation Object.

       clientDataJSONResult

       whose value is the bytes of clientDataJSON.

       attestationConveyancePreferenceOption

       whose value is the value of options.attestation.

       clientExtensionResults

       whose value is an AuthenticationExtensionsClientOutputs object containing extension identifier → client extension output entries. The entries are created by running each extension’s client extension processing algorithm to create the client extension outputs, for each client extension in clientDataJSON.clientExtensions.

    3. Let constructCredentialAlg be an algorithm that takes a global object global, and whose steps are:

       1. If credentialCreationData.attestationConveyancePreferenceOption’s value is

          "none"

          Replace potentially uniquely identifying information with non-identifying versions of the same:

          1. If the AAGUID in the attested credential data is 16 zero bytes, credentialCreationData.attestationObjectResult.fmt is "packed", and "x5c" & "ecdaaKeyId" are both absent from credentialCreationData.attestationObjectResult, then self attestation is being used and no further action is needed.

          2. Otherwise

             1. Replace the AAGUID in the attested credential data with 16 zero bytes.

             2. Set the value of credentialCreationData.attestationObjectResult.fmt to "none", and set the value of credentialCreationData.attestationObjectResult.attStmt to be an empty CBOR map. (See §8.7 None Attestation Statement Format and §6.4.4 Generating an Attestation Object).

          "indirect"

          The client MAY replace the AAGUID and attestation statement with a more privacy-friendly and/or more easily verifiable version of the same data (for example, by employing an Anonymization CA).

          "direct"

          Convey the authenticator's AAGUID and attestation statement, unaltered, to the Relying Party.

       2. Let attestationObject be a new ArrayBuffer, created using global’s %ArrayBuffer%, containing the bytes of credentialCreationData.attestationObjectResult’s value.

       3. Let id be attestationObject.authData.attestedCredentialData.credentialId.

       4. Let pubKeyCred be a new PublicKeyCredential object associated with global whose fields are:

          [[identifier]]

          id

          response

          A new AuthenticatorAttestationResponse object associated with global whose fields are:

          clientDataJSON

          A new ArrayBuffer, created using global’s %ArrayBuffer%, containing the bytes of credentialCreationData.clientDataJSONResult.

          attestationObject

          attestationObject

          [[clientExtensionsResults]]

          A new ArrayBuffer, created using global’s %ArrayBuffer%, containing the bytes of credentialCreationData.clientExtensionResults.

       5. Return pubKeyCred.

    4. For each remaining authenticator in issuedRequests invoke the authenticatorCancel operation on authenticator and remove it from issuedRequests.

    5. Return constructCredentialAlg and terminate this algorithm.

21. Return a DOMException whose name is "NotAllowedError". In order to prevent information leak that could identify the user without consent, this step MUST NOT be executed before lifetimeTimer has expired. See §14.5 Registration Ceremony Privacy for details.

During the above process, the user agent SHOULD show some UI to the user to guide them in the process of selecting and authorizing an authenticator.

This internal method accepts three arguments:

origin

This argument is the relevant settings object's origin, as determined by the calling get() implementation, i.e., CredentialsContainer's Request a Credential abstract operation.

options

This argument is a CredentialRequestOptions object whose options.publicKey member contains a PublicKeyCredentialRequestOptions object specifying the desired attributes of the public key credential to discover.

sameOriginWithAncestors

This argument is a Boolean value which is true if and only if the caller’s environment settings object is same-origin with its ancestors.

Note: This algorithm is synchronous: the Promise resolution/rejection is handled by navigator.credentials.get().

Note: All BufferSource objects used in this algorithm must be snapshotted when the algorithm begins, to avoid potential synchronization issues. The algorithm implementations should get a copy of the bytes held by the buffer source and use that copy for relevant portions of the algorithm.

When this method is invoked, the user agent MUST execute the following algorithm:

1. Assert: options.publicKey is present.

2. If sameOriginWithAncestors is false, return a "NotAllowedError" DOMException.

   Note: This "sameOriginWithAncestors" restriction aims to address the concern raised in the Origin Confusion section of [CREDENTIAL-MANAGEMENT-1], while allowing Relying Party script access to Web Authentication functionality, e.g., when running in a secure context framed document that is same-origin with its ancestors. However, in the future, this specification (in conjunction with [CREDENTIAL-MANAGEMENT-1]) may provide Relying Parties with more fine-grained control--e.g., ranging from allowing only top-level access to Web Authentication functionality, to allowing cross-origin embedded cases--by leveraging [Feature-Policy] once the latter specification becomes stably implemented in user agents.

3. Let options be the value of options.publicKey.

4. If the timeout member of options is present, check if its value lies within a reasonable range as defined by the client and if not, correct it to the closest value lying within that range. Set a timer lifetimeTimer to this adjusted value. If the timeout member of options is not present, then set lifetimeTimer to a client-specific default.

   Note: A suggested reasonable range for the timeout member of options is 15 seconds to 120 seconds.

   Note: The user agent should take cognitive guidelines into considerations regarding timeout for users with special needs.

5. Let callerOrigin be origin. If callerOrigin is an opaque origin, return a DOMException whose name is "NotAllowedError", and terminate this algorithm.

6. Let effectiveDomain be the callerOrigin’s effective domain. If effective domain is not a valid domain, then return a DOMException whose name is "SecurityError" and terminate this algorithm.

   Note: An effective domain may resolve to a host, which can be represented in various manners, such as domain, ipv4 address, ipv6 address, opaque host, or empty host. Only the domain format of host is allowed here. This is for simplification and also is in recognition of various issues with using direct IP address identification in concert with PKI-based security.

7. If options.rpId is not present, then set rpId to effectiveDomain.

   Otherwise:

   1. If options.rpId is not a registrable domain suffix of and is not equal to effectiveDomain, return a DOMException whose name is "SecurityError", and terminate this algorithm.

   2. Set rpId to options.rpId.

      Note: rpId represents the caller’s RP ID. The RP ID defaults to being the caller’s origin's effective domain unless the caller has explicitly set options.rpId when calling get().

8. Let clientExtensions be a new map and let authenticatorExtensions be a new map.

9. If the extensions member of options is present, then for each extensionId → clientExtensionInput of options.extensions:

   1. If extensionId is not supported by this client platform or is not an authentication extension, then continue.

   2. Set clientExtensions[extensionId] to clientExtensionInput.

   3. If extensionId is not an authenticator extension, then continue.

   4. Let authenticatorExtensionInput be the (CBOR) result of running extensionId’s client extension processing algorithm on clientExtensionInput. If the algorithm returned an error, continue.

   5. Set authenticatorExtensions[extensionId] to the base64url encoding of authenticatorExtensionInput.

10. Let collectedClientData be a new CollectedClientData instance whose fields are:

    type

    The string "webauthn.get".

    challenge

    The base64url encoding of options.challenge

    origin

    The serialization of callerOrigin.

    tokenBinding

    The status of Token Binding between the client and the callerOrigin, as well as the Token Binding ID associated with callerOrigin, if one is available.

11. Let clientDataJSON be the JSON-serialized client data constructed from collectedClientData.

12. Let clientDataHash be the hash of the serialized client data represented by clientDataJSON.

13. If the options.signal is present and its aborted flag is set to true, return a DOMException whose name is "AbortError" and terminate this algorithm.

14. Let issuedRequests be a new ordered set.

15. Let savedCredentialIds be a new map.

16. Let authenticators represent a value which at any given instant is a set of client platform-specific handles, where each item identifies an authenticator presently available on this client platform at that instant.

    Note: What qualifies an authenticator as "available" is intentionally unspecified; this is meant to represent how authenticators can be hot-plugged into (e.g., via USB) or discovered (e.g., via NFC or Bluetooth) by the client by various mechanisms, or permanently built into the client.

17. Start lifetimeTimer.

18. While lifetimeTimer has not expired, perform the following actions depending upon lifetimeTimer, and the state and response for each authenticator in authenticators:

    If lifetimeTimer expires,

    For each authenticator in issuedRequests invoke the authenticatorCancel operation on authenticator and remove authenticator from issuedRequests.

    If the user exercises a user agent user-interface option to cancel the process,

    For each authenticator in issuedRequests invoke the authenticatorCancel operation on authenticator and remove authenticator from issuedRequests. Return a DOMException whose name is "NotAllowedError".

    If the signal member is present and the aborted flag is set to true,

    For each authenticator in issuedRequests invoke the authenticatorCancel operation on authenticator and remove authenticator from issuedRequests. Then return a DOMException whose name is "AbortError" and terminate this algorithm.

    If issuedRequests is empty, options.allowCredentials is not empty, and no authenticator will become available for any public key credentials therein,

    Indicate to the user that no eligible credential could be found. When the user acknowledges the dialog, return a DOMException whose name is "NotAllowedError".

    Note: One way a client platform can determine that no authenticator will become available is by examining the transports members of the present PublicKeyCredentialDescriptor items of options.allowCredentials, if any. For example, if all PublicKeyCredentialDescriptor items list only internal, but all internal authenticators have been tried, then there is no possibility of satisfying the request. Alternatively, all PublicKeyCredentialDescriptor items may list transports that the client platform does not support.

    If an authenticator becomes available on this client device,

    Note: This includes the case where an authenticator was available upon lifetimeTimer initiation.

    1. If options.userVerification is set to required and the authenticator is not capable of performing user verification, continue.

    2. Let userVerification be the effective user verification requirement for assertion , a Boolean value, as follows. If options.userVerification

       is set to required

       Let userVerification be true.

       is set to preferred

       If the authenticator

       is capable of user verification

       Let userVerification be true.

       is not capable of user verification

       Let userVerification be false.

       is set to discouraged

       Let userVerification be false.

    3. Let userPresence be a Boolean value set to the inverse of userVerification.

    4. If options.allowCredentials

       is not empty

       1. Let allowCredentialDescriptorList be a new list.

       2. Execute a client platform-specific procedure to determine which, if any, public key credentials described by options.allowCredentials are bound to this authenticator, by matching with rpId, options.allowCredentials.id, and options.allowCredentials.type. Set allowCredentialDescriptorList to this filtered list.

       3. If allowCredentialDescriptorList is empty, continue.

       4. Let distinctTransports be a new ordered set.

       5. If allowCredentialDescriptorList has exactly one value, set savedCredentialIds[authenticator] to allowCredentialDescriptorList[0].id’s value (see here in §6.3.3 The authenticatorGetAssertion Operation for more information).

       6. For each credential descriptor C in allowCredentialDescriptorList, append each value, if any, of C.transports to distinctTransports.

          Note: This will aggregate only distinct values of transports (for this authenticator) in distinctTransports due to the properties of ordered sets.

       7. If distinctTransports

          is not empty

          The client selects one transport value from distinctTransports, possibly incorporating local configuration knowledge of the appropriate transport to use with authenticator in making its selection.

          Then, using transport, invoke the authenticatorGetAssertion operation on authenticator, with rpId, clientDataHash, allowCredentialDescriptorList, userPresence, userVerification, and authenticatorExtensions as parameters.

          is empty

          Using local configuration knowledge of the appropriate transport to use with authenticator, invoke the authenticatorGetAssertion operation on authenticator with rpId, clientDataHash, allowCredentialDescriptorList, userPresence, userVerification, and authenticatorExtensions as parameters.

       is empty

       Using local configuration knowledge of the appropriate transport to use with authenticator, invoke the authenticatorGetAssertion operation on authenticator with rpId, clientDataHash, userPresence, userVerification and authenticatorExtensions as parameters.

       Note: In this case, the Relying Party did not supply a list of acceptable credential descriptors. Thus, the authenticator is being asked to exercise any credential it may possess that is scoped to the Relying Party, as identified by rpId.

    5. Append authenticator to issuedRequests.

    If an authenticator ceases to be available on this client device,

    Remove authenticator from issuedRequests.

    If any authenticator returns a status indicating that the user cancelled the operation,

    1. Remove authenticator from issuedRequests.

    2. For each remaining authenticator in issuedRequests invoke the authenticatorCancel operation on authenticator and remove it from issuedRequests.

       Note: Authenticators may return an indication of "the user cancelled the entire operation". How a user agent manifests this state to users is unspecified.

    If any authenticator returns an error status,

    Remove authenticator from issuedRequests.

    If any authenticator indicates success,

    1. Remove authenticator from issuedRequests.

    2. Let assertionCreationData be a struct whose items are:

       credentialIdResult

       If savedCredentialIds[authenticator] exists, set the value of credentialIdResult to be the bytes of savedCredentialIds[authenticator]. Otherwise, set the value of credentialIdResult to be the bytes of the credential ID returned from the successful authenticatorGetAssertion operation, as defined in §6.3.3 The authenticatorGetAssertion Operation.

       clientDataJSONResult

       whose value is the bytes of clientDataJSON.

       authenticatorDataResult

       whose value is the bytes of the authenticator data returned by the authenticator.

       signatureResult

       whose value is the bytes of the signature value returned by the authenticator.

       userHandleResult

       If the authenticator returned a user handle, set the value of userHandleResult to be the bytes of the returned user handle. Otherwise, set the value of userHandleResult to null.

       clientExtensionResults

       whose value is an AuthenticationExtensionsClientOutputs object containing extension identifier → client extension output entries. The entries are created by running each extension’s client extension processing algorithm to create the client extension outputs, for each client extension in clientDataJSON.clientExtensions.

    3. Let constructAssertionAlg be an algorithm that takes a global object global, and whose steps are:

       1. Let pubKeyCred be a new PublicKeyCredential object associated with global whose fields are:

          [[identifier]]

          A new ArrayBuffer, created using global’s %ArrayBuffer%, containing the bytes of assertionCreationData.credentialIdResult.

          response

          A new AuthenticatorAssertionResponse object associated with global whose fields are:

          clientDataJSON

          A new ArrayBuffer, created using global’s %ArrayBuffer%, containing the bytes of assertionCreationData.clientDataJSONResult.

          authenticatorData

          A new ArrayBuffer, created using global’s %ArrayBuffer%, containing the bytes of assertionCreationData.authenticatorDataResult.

          signature

          A new ArrayBuffer, created using global’s %ArrayBuffer%, containing the bytes of assertionCreationData.signatureResult.

          userHandle

          If assertionCreationData.userHandleResult is null, set this field to null. Otherwise, set this field to a new ArrayBuffer, created using global’s %ArrayBuffer%, containing the bytes of assertionCreationData.userHandleResult.

          [[clientExtensionsResults]]

          A new ArrayBuffer, created using global’s %ArrayBuffer%, containing the bytes of assertionCreationData.clientExtensionResults.

       2. Return pubKeyCred.

    4. For each remaining authenticator in issuedRequests invoke the authenticatorCancel operation on authenticator and remove it from issuedRequests.

    5. Return constructAssertionAlg and terminate this algorithm.

19. Return a DOMException whose name is "NotAllowedError". In order to prevent information leak that could identify the user without consent, this step MUST NOT be executed before lifetimeTimer has expired. See §14.6 Authentication Ceremony Privacy for details.

During the above process, the user agent SHOULD show some UI to the user to guide them in the process of selecting and authorizing an authenticator with which to complete the operation.

Calling the [[preventSilentAccess]](credential, sameOriginWithAncestors) method will have no effect on authenticators that require an authorization gesture, but setting that flag may potentially exclude authenticators that can operate without user intervention.

This internal method accepts no arguments.

WebAuthn Relying Parties use this method to determine whether they can create a new credential using a user-verifying platform authenticator. Upon invocation, the client employs a client platform-specific procedure to discover available user-verifying platform authenticators. If any are discovered, the promise is resolved with the value of true. Otherwise, the promise is resolved with the value of false. Based on the result, the Relying Party can take further actions to guide the user to create a credential.

This method has no arguments and returns a Boolean value.

 partial   interface   PublicKeyCredential  {
     static   Promise < boolean >   isUserVerifyingPlatformAuthenticatorAvailable  ();
};

clientDataJSON , of type ArrayBuffer, readonly

This attribute contains a JSON serialization of the client data passed to the authenticator by the client in its call to either create() or get().

clientDataJSON

This attribute, inherited from AuthenticatorResponse, contains the JSON-serialized client data (see §6.4 Attestation) passed to the authenticator by the client in order to generate this credential. The exact JSON serialization MUST be preserved, as the hash of the serialized client data has been computed over it.

attestationObject , of type ArrayBuffer, readonly

This attribute contains an attestation object, which is opaque to, and cryptographically protected against tampering by, the client. The attestation object contains both authenticator data and an attestation statement. The former contains the AAGUID, a unique credential ID, and the credential public key. The contents of the attestation statement are determined by the attestation statement format used by the authenticator. It also contains any additional information that the Relying Party's server requires to validate the attestation statement, as well as to decode and validate the authenticator data along with the JSON-serialized client data. For more details, see §6.4 Attestation, §6.4.4 Generating an Attestation Object, and Figure 5.

clientDataJSON

This attribute, inherited from AuthenticatorResponse, contains the JSON-serialized client data (see §5.10.1 Client Data Used in WebAuthn Signatures (dictionary CollectedClientData)) passed to the authenticator by the client in order to generate this assertion. The exact JSON serialization MUST be preserved, as the hash of the serialized client data has been computed over it.

authenticatorData , of type ArrayBuffer, readonly

This attribute contains the authenticator data returned by the authenticator. See §6.1 Authenticator Data.

signature , of type ArrayBuffer, readonly

This attribute contains the raw signature returned from the authenticator. See §6.3.3 The authenticatorGetAssertion Operation.

userHandle , of type ArrayBuffer, readonly, nullable

This attribute contains the user handle returned from the authenticator, or null if the authenticator did not return a user handle. See §6.3.3 The authenticatorGetAssertion Operation.

This dictionary is used to supply additional parameters when creating a new credential.

type , of type PublicKeyCredentialType

This member specifies the type of credential to be created.

alg , of type COSEAlgorithmIdentifier

This member specifies the cryptographic signature algorithm with which the newly generated credential will be used, and thus also the type of asymmetric key pair to be generated, e.g., RSA or Elliptic Curve.

Note: we use "alg" as the latter member name, rather than spelling-out "algorithm", because it will be serialized into a message to the authenticator, which may be sent over a low-bandwidth link.

rp , of type PublicKeyCredentialRpEntity

This member contains data about the Relying Party responsible for the request.

Its value’s name member is REQUIRED. See §5.4.1 Public Key Entity Description (dictionary PublicKeyCredentialEntity) for further details.

Its value’s id member specifies the RP ID the credential should be scoped to. If omitted, its value will be the CredentialsContainer object’s relevant settings object's origin's effective domain. See §5.4.2 Relying Party Parameters for Credential Generation (dictionary PublicKeyCredentialRpEntity) for further details.

user , of type PublicKeyCredentialUserEntity

This member contains data about the user account for which the Relying Party is requesting attestation.

Its value’s name, displayName and id members are REQUIRED. See §5.4.1 Public Key Entity Description (dictionary PublicKeyCredentialEntity) and §5.4.3 User Account Parameters for Credential Generation (dictionary PublicKeyCredentialUserEntity) for further details.

challenge , of type BufferSource

This member contains a challenge intended to be used for generating the newly created credential’s attestation object. See the §13.1 Cryptographic Challenges security consideration.

pubKeyCredParams , of type sequence<PublicKeyCredentialParameters>

This member contains information about the desired properties of the credential to be created. The sequence is ordered from most preferred to least preferred. The client makes a best-effort to create the most preferred credential that it can.

timeout , of type unsigned long

This member specifies a time, in milliseconds, that the caller is willing to wait for the call to complete. This is treated as a hint, and MAY be overridden by the client.

excludeCredentials , of type sequence<PublicKeyCredentialDescriptor>, defaulting to None

This member is intended for use by Relying Parties that wish to limit the creation of multiple credentials for the same account on a single authenticator. The client is requested to return an error if the new credential would be created on an authenticator that also contains one of the credentials enumerated in this parameter.

authenticatorSelection , of type AuthenticatorSelectionCriteria

This member is intended for use by Relying Parties that wish to select the appropriate authenticators to participate in the create() operation.

attestation , of type AttestationConveyancePreference, defaulting to "none"

This member is intended for use by Relying Parties that wish to express their preference for attestation conveyance. The default is none.

extensions , of type AuthenticationExtensionsClientInputs

This member contains additional parameters requesting additional processing by the client and authenticator. For example, the caller may request that only authenticators with certain capabilities be used to create the credential, or that particular information be returned in the attestation object. Some extensions are defined in §9 WebAuthn Extensions; consult the IANA "WebAuthn Extension Identifier" registry established by [WebAuthn-Registries] for an up-to-date list of registered WebAuthn Extensions.

name , of type DOMString

A human-palatable name for the entity. Its function depends on what the PublicKeyCredentialEntity represents:

• When inherited by PublicKeyCredentialRpEntity it is a human-palatable identifier for the Relying Party, intended only for display. For example, "ACME Corporation", "Wonderful Widgets, Inc." or "ОАО Примертех".

  • Relying Parties SHOULD perform enforcement, as prescribed in Section 2.3 of [RFC8266] for the Nickname Profile of the PRECIS FreeformClass [RFC8264], when setting name's value, or displaying the value to the user.

  • Clients SHOULD perform enforcement, as prescribed in Section 2.3 of [RFC8266] for the Nickname Profile of the PRECIS FreeformClass [RFC8264], on name's value prior to displaying the value to the user or including the value as a parameter of the authenticatorMakeCredential operation.

• When inherited by PublicKeyCredentialUserEntity, it is a human-palatable identifier for a user account. It is intended only for display, i.e., aiding the user in determining the difference between user accounts with similar displayNames. For example, "alexm", "alex.p.mueller@example.com" or "+14255551234".

  • The Relying Party MAY let the user choose this value. The Relying Party SHOULD perform enforcement, as prescribed in Section 3.4.3 of [RFC8265] for the UsernameCasePreserved Profile of the PRECIS IdentifierClass [RFC8264], when setting name's value, or displaying the value to the user.

  • Clients SHOULD perform enforcement, as prescribed in Section 3.4.3 of [RFC8265] for the UsernameCasePreserved Profile of the PRECIS IdentifierClass [RFC8264], on name's value prior to displaying the value to the user or including the value as a parameter of the authenticatorMakeCredential operation.

When clients, client platforms, or authenticators display a name's value, they should always use UI elements to provide a clear boundary around the displayed value, and not allow overflow into other elements [css-overflow-3].

Authenticators MUST accept and store a 64-byte minimum length for a name member’s value. Authenticators MAY truncate a name member’s value to a length equal to or greater than 64 bytes.

icon , of type USVString

A serialized URL which resolves to an image associated with the entity. For example, this could be a user’s avatar or a Relying Party's logo. This URL MUST be an a priori authenticated URL. Authenticators MUST accept and store a 128-byte minimum length for an icon member’s value. Authenticators MAY ignore an icon member’s value if its length is greater than 128 bytes. The URL’s scheme MAY be "data" to avoid fetches of the URL, at the cost of needing more storage.

id , of type DOMString

A unique identifier for the Relying Party entity, which sets the RP ID.

id , of type BufferSource

The user handle of the user account entity. To ensure secure operation, authentication and authorization decisions MUST be made on the basis of this id member, not the displayName nor name members. See Section 6.1 of [RFC8266].

displayName , of type DOMString

A human-palatable name for the user account, intended only for display. For example, "Alex P. Müller" or "田中 倫". The Relying Party SHOULD let the user choose this, and SHOULD NOT restrict the choice more than necessary.

• Relying Parties SHOULD perform enforcement, as prescribed in Section 2.3 of [RFC8266] for the Nickname Profile of the PRECIS FreeformClass [RFC8264], when setting displayName's value, or displaying the value to the user.

• Clients SHOULD perform enforcement, as prescribed in Section 2.3 of [RFC8266] for the Nickname Profile of the PRECIS FreeformClass [RFC8264], on displayName's value prior to displaying the value to the user or including the value as a parameter of the authenticatorMakeCredential operation.

When clients, client platforms, or authenticators display a displayName's value, they should always use UI elements to provide a clear boundary around the displayed value, and not allow overflow into other elements [css-overflow-3].

Authenticators MUST accept and store a 64-byte minimum length for a displayName member’s value. Authenticators MAY truncate a displayName member’s value to a length equal to or greater than 64 bytes.

authenticatorAttachment , of type AuthenticatorAttachment

If this member is present, eligible authenticators are filtered to only authenticators attached with the specified §5.4.5 Authenticator Attachment Enumeration (enum AuthenticatorAttachment).

requireResidentKey , of type boolean, defaulting to false

This member describes the Relying Party's requirements regarding resident credentials. If the parameter is set to true, the authenticator MUST create a client-side-resident public key credential source when creating a public key credential.

userVerification , of type UserVerificationRequirement, defaulting to "preferred"

This member describes the Relying Party's requirements regarding user verification for the create() operation. Eligible authenticators are filtered to only those capable of satisfying this requirement.

platform

This value indicates platform attachment.

cross-platform

This value indicates cross-platform attachment.

none

This value indicates that the Relying Party is not interested in authenticator attestation. For example, in order to potentially avoid having to obtain user consent to relay identifying information to the Relying Party, or to save a roundtrip to an Attestation CA.

This is the default value.

indirect

This value indicates that the Relying Party prefers an attestation conveyance yielding verifiable attestation statements, but allows the client to decide how to obtain such attestation statements. The client MAY replace the authenticator-generated attestation statements with attestation statements generated by an Anonymization CA, in order to protect the user’s privacy, or to assist Relying Parties with attestation verification in a heterogeneous ecosystem.

Note: There is no guarantee that the Relying Party will obtain a verifiable attestation statement in this case. For example, in the case that the authenticator employs self attestation.

direct

This value indicates that the Relying Party wants to receive the attestation statement as generated by the authenticator.

type , of type DOMString

This member contains the string "webauthn.create" when creating new credentials, and "webauthn.get" when getting an assertion from an existing credential. The purpose of this member is to prevent certain types of signature confusion attacks (where an attacker substitutes one legitimate signature for another).

challenge , of type DOMString

This member contains the base64url encoding of the challenge provided by the Relying Party. See the §13.1 Cryptographic Challenges security consideration.

origin , of type DOMString

This member contains the fully qualified origin of the requester, as provided to the authenticator by the client, in the syntax defined by [RFC6454].

tokenBinding , of type TokenBinding

This OPTIONAL member contains information about the state of the Token Binding protocol [TokenBinding] used when communicating with the Relying Party. Its absence indicates that the client doesn’t support token binding.

status , of type TokenBindingStatus

This member is one of the following:

supported

Indicates the client supports token binding, but it was not negotiated when communicating with the Relying Party.

present

Indicates token binding was used when communicating with the Relying Party. In this case, the id member MUST be present.

id , of type DOMString

This member MUST be present if status is present, and MUST be a base64url encoding of the Token Binding ID that was used when communicating with the Relying Party.

Note: Obtaining a Token Binding ID is a client platform-specific operation.

The CollectedClientData structure is used by the client to compute the following quantities:

JSON-serialized client data

This is the result of JSON-serializing to bytes a CollectedClientData dictionary.

Hash of the serialized client data

This is the hash (computed using SHA-256) of the JSON-serialized client data, as constructed by the client.

This enumeration defines the valid credential types. It is an extension point; values can be added to it in the future, as more credential types are defined. The values of this enumeration are used for versioning the Authentication Assertion and attestation structures according to the type of the authenticator.

Currently one credential type is defined, namely " public-key ".

type , of type PublicKeyCredentialType

This member contains the type of the public key credential the caller is referring to.

id , of type BufferSource

This member contains the credential ID of the public key credential the caller is referring to.

transports , of type sequence<AuthenticatorTransport>

This OPTIONAL member contains a hint as to how the client might communicate with the managing authenticator of the public key credential the caller is referring to.