webAuthn.ts

export interface IWebAuth {
    rpName: string,
    rpId: string,
    credentialOpt?: PublicKeyCredentialCreationOptions
    assertionOpt?: PublicKeyCredentialRequestOptions
}

export interface IAssertionOpt {
    challenge: string
}

export interface ICredentialOpt extends IAssertionOpt {
    userId: string;
    userName: string;
    userDisplayName: string;
}
export function webAuthn({
    rpName,
    rpId,
    credentialOpt,
    assertionOpt
}: IWebAuth) {
    const getCredential = async (
        {
            userId,
            userName,
            userDisplayName,
            challenge
        }: ICredentialOpt
    ) => {
        const publicKeyCredentialCreationOptions = {
            rp: {
                name: rpName,
                id: rpId
            },
            user: {
                id: Uint8Array.from(
                    userId, c => c.charCodeAt(0)),
                name: userName,
                displayName: userDisplayName
            },
            challenge: Uint8Array.from(
                challenge, c => c.charCodeAt(0)),
            pubKeyCredParams: [
                {
                    type: "public-key",
                    alg: -7
                },
                {
                    type: "public-key",
                    alg: -257
                }
            ],
            timeout: 60000,
            excludeCredentials: [],
            authenticatorSelection: {
                residentKey: "preferred",
                requireResidentKey: false,
                userVerification: "required"
            },
            attestation: "none",
            extensions: {
                credProps: true
            },
            ...credentialOpt
        } as PublicKeyCredentialCreationOptions
        return await navigator.credentials.create({
            publicKey: publicKeyCredentialCreationOptions
        });
    }


    const getAssertion = async ({ challenge }: IAssertionOpt) => {
        const publicKeyCredentialRequestOptions = {
            challenge: Uint8Array.from(
                challenge, c => c.charCodeAt(0)),
            allowCredentials: [],
            rpId: rpId,
            timeout: 60000,
            userVerification: "required",
            ...assertionOpt
        } as PublicKeyCredentialRequestOptions
        return await navigator.credentials.get({
            publicKey: publicKeyCredentialRequestOptions
        });
    }
    return { getCredential, getAssertion } as const
}