clienting.ts

import { Agent, Controller } from './controller';
import { Tier } from '../core/salter';
import { Authenticater } from '../core/authing';
import { ExternalModule, KeyManager } from '../core/keeping';

import { Identifier } from './aiding';
import { Contacts, Challenges } from './contacting';
import { Oobis, Operations, KeyEvents, KeyStates } from './coring';
import { Credentials, Ipex, Registries, Schemas } from './credentialing';
import { Notifications } from './notifying';
import { Escrows } from './escrowing';
import { Groups } from './grouping';
import { Exchanges } from './exchanging';

const DEFAULT_BOOT_URL = 'http://localhost:3903';

class State {
    agent: any | null;
    controller: any | null;
    ridx: number;
    pidx: number;

    constructor() {
        this.agent = null;
        this.controller = null;
        this.pidx = 0;
        this.ridx = 0;
    }
}

/** SignifyClient */
export class SignifyClient {
    public controller: Controller;
    public url: string;
    public bran: string;
    public pidx: number;
    public agent: Agent | null;
    public authn: Authenticater | null;
    public manager: KeyManager | null;
    public tier: Tier;
    public bootUrl: string;
    public exteralModules: ExternalModule[];

    /**
     * SignifyClient constructor
     * @param {string} url KERIA admin interface URL
     * @param {string} bran Base64 21 char string that is used as base material for seed of the client AID
     * @param {Tier} tier Security tier for generating keys of the client AID (high | mewdium | low)
     * @param {string} bootUrl KERIA boot interface URL
     * @param {ExternalModule[]} externalModules list of external modules to load
     */
    constructor(
        url: string,
        bran: string,
        tier: Tier = Tier.low,
        bootUrl: string = DEFAULT_BOOT_URL,
        externalModules: ExternalModule[] = []
    ) {
        this.url = url;
        if (bran.length < 21) {
            throw Error('bran must be 21 characters');
        }
        this.bran = bran;
        this.pidx = 0;
        this.controller = new Controller(bran, tier);
        this.authn = null;
        this.agent = null;
        this.manager = null;
        this.tier = tier;
        this.bootUrl = bootUrl;
        this.exteralModules = externalModules;
    }

    get data() {
        return [this.url, this.bran, this.pidx, this.authn];
    }

    /**
     * Boot a KERIA agent
     * @async
     * @returns {Promise<Response>} A promise to the result of the boot
     */
    async boot(): Promise<Response> {
        const [evt, sign] = this.controller?.event ?? [];
        const data = {
            icp: evt.ked,
            sig: sign.qb64,
            stem: this.controller?.stem,
            pidx: 1,
            tier: this.controller?.tier,
        };

        return await fetch(this.bootUrl + '/boot', {
            method: 'POST',
            body: JSON.stringify(data),
            headers: {
                'Content-Type': 'application/json',
            },
        });
    }

    /**
     * Get state of the agent and the client
     * @async
     * @returns {Promise<Response>} A promise to the state
     */
    async state(): Promise<State> {
        const caid = this.controller?.pre;

        const res = await fetch(this.url + `/agent/${caid}`);
        if (res.status == 404) {
            throw new Error(`agent does not exist for controller ${caid}`);
        }

        const data = await res.json();
        const state = new State();
        state.agent = data.agent ?? {};
        state.controller = data.controller ?? {};
        state.ridx = data.ridx ?? 0;
        state.pidx = data.pidx ?? 0;
        return state;
    }

    /**  Connect to a KERIA agent
     * @async
     */
    async connect() {
        const state = await this.state();
        this.pidx = state.pidx;
        //Create controller representing the local client AID
        this.controller = new Controller(
            this.bran,
            this.tier,
            0,
            state.controller
        );
        this.controller.ridx = state.ridx !== undefined ? state.ridx : 0;
        // Create agent representing the AID of KERIA cloud agent
        this.agent = new Agent(state.agent);
        if (this.agent.anchor != this.controller.pre) {
            throw Error(
                'commitment to controller AID missing in agent inception event'
            );
        }
        if (this.controller.serder.ked.s == 0) {
            await this.approveDelegation();
        }
        this.manager = new KeyManager(
            this.controller.salter,
            this.exteralModules
        );
        this.authn = new Authenticater(
            this.controller.signer,
            this.agent.verfer!
        );
    }

    /**
     * Fetch a resource from the KERIA agent
     * @async
     * @param {string} path Path to the resource
     * @param {string} method HTTP method
     * @param {any} data Data to be sent in the body of the resource
     * @param {Headers} [extraHeaders] Optional extra headers to be sent with the request
     * @returns {Promise<Response>} A promise to the result of the fetch
     */
    async fetch(
        path: string,
        method: string,
        data: any,
        extraHeaders?: Headers
    ): Promise<Response> {
        const headers = new Headers();
        let signed_headers = new Headers();
        const final_headers = new Headers();

        headers.set('Signify-Resource', this.controller.pre);
        headers.set(
            'Signify-Timestamp',
            new Date().toISOString().replace('Z', '000+00:00')
        );
        headers.set('Content-Type', 'application/json');

        const _body = method == 'GET' ? null : JSON.stringify(data);
        if (_body !== null) {
            headers.set('Content-Length', String(_body.length));
        }
        if (this.authn) {
            signed_headers = this.authn.sign(
                headers,
                method,
                path.split('?')[0]
            );
        } else {
            throw new Error('client need to call connect first');
        }

        signed_headers.forEach((value, key) => {
            final_headers.set(key, value);
        });
        if (extraHeaders !== undefined) {
            extraHeaders.forEach((value, key) => {
                final_headers.append(key, value);
            });
        }
        const res = await fetch(this.url + path, {
            method: method,
            body: _body,
            headers: final_headers,
        });
        if (!res.ok) {
            const error = await res.text();
            throw new Error(error);
        }
        const isSameAgent =
            this.agent?.pre === res.headers.get('signify-resource');
        if (!isSameAgent) {
            throw new Error('message from a different remote agent');
        }

        const verification = this.authn.verify(
            res.headers,
            method,
            path.split('?')[0]
        );
        if (verification) {
            return res;
        } else {
            throw new Error('response verification failed');
        }
    }

    /**
     * Fetch a resource from from an external URL with headers signed by an AID
     * @async
     * @param {string} url URL of the resource
     * @param {string} path Path to the resource
     * @param {string} method HTTP method
     * @param {any} data Data to be sent in the body of the resource
     * @param {string} aidName Name or alias of the AID to be used for signing
     * @returns {Promise<Response>} A promise to the result of the fetch
     */
    async signedFetch(
        url: string,
        path: string,
        method: string,
        data: any,
        aidName: string
    ): Promise<Response> {
        const hab = await this.identifiers().get(aidName);
        const keeper = this.manager!.get(hab);

        const authenticator = new Authenticater(
            keeper.signers[0],
            keeper.signers[0].verfer
        );

        const headers = new Headers();
        headers.set('Signify-Resource', hab.prefix);
        headers.set(
            'Signify-Timestamp',
            new Date().toISOString().replace('Z', '000+00:00')
        );

        if (data !== null) {
            headers.set('Content-Length', data.length);
        } else {
            headers.set('Content-Length', '0');
        }
        const signed_headers = authenticator.sign(
            headers,
            method,
            path.split('?')[0]
        );
        let _body = null;
        if (method != 'GET') {
            if (data instanceof FormData) {
                _body = data;
                // do not set the content type, let the browser do it
                // headers.set('Content-Type', 'multipart/form-data')
            } else {
                _body = JSON.stringify(data);
                headers.set('Content-Type', 'application/json');
            }
        } else {
            headers.set('Content-Type', 'application/json');
        }

        return await fetch(url + path, {
            method: method,
            body: _body,
            headers: signed_headers,
        });
    }

    /**
     * Approve the delegation of the client AID to the KERIA agent
     * @async
     * @returns {Promise<Response>} A promise to the result of the approval
     */
    async approveDelegation(): Promise<Response> {
        const sigs = this.controller.approveDelegation(this.agent!);

        const data = {
            ixn: this.controller.serder.ked,
            sigs: sigs,
        };

        return await fetch(
            this.url + '/agent/' + this.controller.pre + '?type=ixn',
            {
                method: 'PUT',
                body: JSON.stringify(data),
                headers: {
                    'Content-Type': 'application/json',
                },
            }
        );
    }

    /**
     * Save old client passcode in KERIA agent
     * @async
     * @param {string} passcode Passcode to be saved
     * @returns {Promise<Response>} A promise to the result of the save
     */
    async saveOldPasscode(passcode: string): Promise<Response> {
        const caid = this.controller?.pre;
        const body = { salt: passcode };
        return await fetch(this.url + '/salt/' + caid, {
            method: 'PUT',
            body: JSON.stringify(body),
            headers: {
                'Content-Type': 'application/json',
            },
        });
    }

    /**
     * Delete a saved passcode from KERIA agent
     * @async
     * @returns {Promise<Response>} A promise to the result of the deletion
     */
    async deletePasscode(): Promise<Response> {
        const caid = this.controller?.pre;
        return await fetch(this.url + '/salt/' + caid, {
            method: 'DELETE',
            headers: {
                'Content-Type': 'application/json',
            },
        });
    }

    /**
     * Rotate the client AID
     * @async
     * @param {string} nbran Base64 21 char string that is used as base material for the new seed
     * @param {Array<string>} aids List of managed AIDs to be rotated
     * @returns {Promise<Response>} A promise to the result of the rotation
     */
    async rotate(nbran: string, aids: string[]): Promise<Response> {
        const data = this.controller.rotate(nbran, aids);
        return await fetch(this.url + '/agent/' + this.controller.pre, {
            method: 'PUT',
            body: JSON.stringify(data),
            headers: {
                'Content-Type': 'application/json',
            },
        });
    }

    /**
     * Get identifiers resource
     * @returns {Identifier}
     */
    identifiers(): Identifier {
        return new Identifier(this);
    }

    /**
     * Get OOBIs resource
     * @returns {Oobis}
     */
    oobis(): Oobis {
        return new Oobis(this);
    }

    /**
     * Get operations resource
     * @returns {Operations}
     */
    operations(): Operations {
        return new Operations(this);
    }

    /**
     * Get keyEvents resource
     * @returns {KeyEvents}
     */
    keyEvents(): KeyEvents {
        return new KeyEvents(this);
    }

    /**
     * Get keyStates resource
     * @returns {KeyStates}
     */
    keyStates(): KeyStates {
        return new KeyStates(this);
    }

    /**
     * Get credentials resource
     * @returns {Credentials}
     */
    credentials(): Credentials {
        return new Credentials(this);
    }

    /**
     * Get IPEX resource
     * @returns {Ipex}
     */
    ipex(): Ipex {
        return new Ipex(this);
    }

    /**
     * Get registries resource
     * @returns {Registries}
     */
    registries(): Registries {
        return new Registries(this);
    }

    /**
     * Get schemas resource
     * @returns {Schemas}
     */
    schemas(): Schemas {
        return new Schemas(this);
    }

    /**
     * Get challenges resource
     * @returns {Challenges}
     */
    challenges(): Challenges {
        return new Challenges(this);
    }

    /**
     * Get contacts resource
     * @returns {Contacts}
     */
    contacts(): Contacts {
        return new Contacts(this);
    }

    /**
     * Get notifications resource
     * @returns {Notifications}
     */
    notifications(): Notifications {
        return new Notifications(this);
    }

    /**
     * Get escrows resource
     * @returns {Escrows}
     */
    escrows(): Escrows {
        return new Escrows(this);
    }

    /**
     * Get groups resource
     * @returns {Groups}
     */
    groups(): Groups {
        return new Groups(this);
    }

    /**
     * Get exchange resource
     * @returns {Exchanges}
     */
    exchanges(): Exchanges {
        return new Exchanges(this);
    }
}