moth/theme/moth.mjs

578 lines
15 KiB
JavaScript

/**
* Hash/digest functions
*/
class Hash {
/**
* Dan Bernstein hash
*
* Used until MOTH v3.5
*
* @param {string} buf Input
* @returns {number}
*/
static djb2(buf) {
let h = 5381
for (let c of (new TextEncoder()).encode(buf)) { // Encode as UTF-8 and read in each byte
// JavaScript converts everything to a signed 32-bit integer when you do bitwise operations.
// So we have to do "unsigned right shift" by zero to get it back to unsigned.
h = ((h * 33) + c) >>> 0
}
return h
}
/**
* Dan Bernstein hash with xor improvement
*
* @param {string} buf Input
* @returns {number}
*/
static djb2xor(buf) {
let h = 5381
for (let c of (new TextEncoder()).encode(buf)) {
h = ((h * 33) ^ c) >>> 0
}
return h
}
/**
* SHA 256
*
* Used until MOTH v4.5
*
* @param {string} buf Input
* @returns {Promise.<string>} hex-encoded digest
*/
static async sha256(buf) {
const msgUint8 = new TextEncoder().encode(buf)
const hashBuffer = await crypto.subtle.digest('SHA-256', msgUint8)
const hashArray = Array.from(new Uint8Array(hashBuffer))
return this.hexlify(hashArray);
}
/**
* Hex-encode a byte array
*
* @param {number[]} buf Byte array
* @returns {string}
*/
static hexlify(buf) {
return buf.map(b => b.toString(16).padStart(2, "0")).join("")
}
/**
* Apply every hash to the input buffer.
*
* @param {string} buf Input
* @returns {Promise.<string[]>}
*/
static async All(buf) {
return [
String(this.djb2(buf)),
String(this.djb2xor(buf)),
await this.sha256(buf),
]
}
}
/**
* A point award.
*/
class Award {
constructor(when, teamid, category, points) {
/** Unix epoch timestamp for this award
* @type {number}
*/
this.When = when
/** Team ID this award belongs to
* @type {string}
*/
this.TeamID = teamid
/** Puzzle category for this award
* @type {string}
*/
this.Category = category
/** Points value of this award
* @type {number}
*/
this.Points = points
}
}
/**
* A puzzle.
*
* A new Puzzle only knows its category and point value.
* If you want to populate it with meta-information, you must call Populate().
*
* Parameters created by Populate are described in the server source code:
* {@link https://pkg.go.dev/github.com/dirtbags/moth/v4/pkg/transpile#Puzzle}
*
*/
class Puzzle {
/**
* @param {Server} server
* @param {string} category
* @param {number} points
*/
constructor (server, category, points) {
if (points < 1) {
throw(`Invalid points value: ${points}`)
}
/** Server where this puzzle lives
* @type {Server}
*/
this.server = server
/** Category this puzzle belongs to */
this.Category = String(category)
/** Point value of this puzzle */
this.Points = Number(points)
/** Error returned trying to retrieve this puzzle */
this.Error = {
/** Status code provided by server */
Status: 0,
/** Status text provided by server */
StatusText: "",
/** Full text of server error */
Body: "",
}
}
/**
* Populate this Puzzle object with meta-information from the server.
*/
async Populate() {
let resp = await this.Get("puzzle.json")
if (!resp.ok) {
let body = await resp.text()
this.Error = {
Status: resp.status,
StatusText: resp.statusText,
Body: body,
}
throw(this.Error)
}
let obj = await resp.json()
Object.assign(this, obj)
// Make sure lists are lists
this.AnswerHashes ||= []
this.Answers ||= []
this.Attachments ||= []
this.Authors ||= []
this.Debug.Errors ||= []
this.Debug.Hints ||= []
this.Debug.Log ||= []
this.KSAs ||= []
this.Scripts ||= []
}
/**
* Get a resource associated with this puzzle.
*
* @param {string} filename Attachment/Script to retrieve
* @returns {Promise.<Response>}
*/
Get(filename) {
return this.server.GetContent(this.Category, this.Points, filename)
}
/**
* Check if a string is possibly correct.
*
* The server sends a list of answer hashes with each puzzle: this method
* checks to see if any of those hashes match a hash of the string.
*
* The MOTH development team likes obscure hash functions with a lot of
* collisions, which means that a given input may match another possible
* string's hash. We do this so that if you run a brute force attack against
* the list of hashes, you have to write your own brute force program, and
* you still have to pick through a lot of potentially correct answers when
* it's done.
*
* @param {string} str User-submitted possible answer
* @returns {Promise.<boolean>}
*/
async IsPossiblyCorrect(str) {
let userAnswerHashes = await Hash.All(str)
for (let pah of this.AnswerHashes) {
for (let uah of userAnswerHashes) {
if (pah == uah) {
return true
}
}
}
return false
}
/**
* Submit a proposed answer for points.
*
* The returned promise will fail if anything goes wrong, including the
* proposed answer being rejected.
*
* @param {string} proposed Answer to submit
* @returns {Promise.<string>} Success message
*/
SubmitAnswer(proposed) {
return this.server.SubmitAnswer(this.Category, this.Points, proposed)
}
}
/**
* MOTH instance state.
*/
class State {
/**
* @param {Server} server Server where we got this
* @param {Object} obj Raw state data
*/
constructor(server, obj) {
for (let key of ["Config", "Messages", "TeamNames", "PointsLog"]) {
if (!obj[key]) {
throw(`Missing state property: ${key}`)
}
}
this.server = server
/** Configuration */
this.Config = {
/** Is the server in development mode?
* @type {boolean}
*/
Devel: obj.Config.Devel,
}
/** Global messages, in HTML
* @type {string}
*/
this.Messages = obj.Messages
/** Map from Team ID to Team Name
* @type {Object.<string,string>}
*/
this.TeamNames = obj.TeamNames
/** Map from category name to puzzle point values
* @type {Object.<string,number>}
*/
this.PointsByCategory = obj.Puzzles
/** Log of points awarded
* @type {Award[]}
*/
this.PointsLog = obj.PointsLog.map(entry => new Award(entry[0], entry[1], entry[2], entry[3]))
}
/**
* Returns a sorted list of open category names
*
* @returns {string[]} List of categories
*/
Categories() {
let ret = []
for (let category in this.PointsByCategory) {
ret.push(category)
}
ret.sort()
return ret
}
/**
* Check whether a category contains unsolved puzzles.
*
* The server adds a puzzle with 0 points in every "solved" category,
* so this just checks whether there is a 0-point puzzle in the category's point list.
*
* @param {string} category
* @returns {boolean}
*/
ContainsUnsolved(category) {
return !this.PointsByCategory[category].includes(0)
}
/**
* Is the server in development mode?
*
* @returns {boolean}
*/
DevelopmentMode() {
return this.Config && this.Config.Devel
}
/**
* Return all open puzzles.
*
* The returned list will be sorted by (category, points).
* If not categories are given, all puzzles will be returned.
*
* @param {string} categories Limit results to these categories
* @returns {Puzzle[]}
*/
Puzzles(...categories) {
if (categories.length == 0) {
categories = this.Categories()
}
let ret = []
for (let category of categories) {
for (let points of this.PointsByCategory[category]) {
if (0 == points) {
// This means all potential puzzles in the category are open
continue
}
let p = new Puzzle(this.server, category, points)
ret.push(p)
}
}
return ret
}
/**
* Has this puzzle been solved by this team?
*
* @param {Puzzle} puzzle
* @param {string} teamID Team to check, default the logged-in team
* @returns {boolean}
*/
IsSolved(puzzle, teamID="self") {
for (let award of this.PointsLog) {
if (
(award.Category == puzzle.Category)
&& (award.Points == puzzle.Points)
&& (award.TeamID == teamID)
) {
return true
}
}
return false
}
/**
* Map from team ID to points.
*
* A special "max" property contains the highest number of points in this map.
*
* @typedef {Object.<string, number>} TeamPointsDict
* @property {Number} max Highest number of points
*/
/**
* Map from category to PointsDict.
*
* @typedef {Object.<string, TeamPointsDict>} CategoryTeamPointsDict
*/
/**
* Score snapshot.
*
* @typedef {Object} ScoreSnapshot
* @property {number} when Epoch time of this snapshot
* @property {CategoryTeamPointsDict} snapshot
*/
/**
* Replay scores.
*
* @yields {ScoreSnapshot} Snapshot at a point in time
*/
* ScoreHistory() {
/** @type {CategoryTeamPointsDict} */
let categoryTeamPoints = {}
for (let award of this.PointsLog) {
let teamPoints = (categoryTeamPoints[award.Category] ??= {})
let points = teamPoints[award.TeamID] || 0
let max = teamPoints.max || 0
points += award.Points
teamPoints[award.TeamID] = points
teamPoints.max = Math.max(points, max)
/** @type ScoreSnapshot */
let snapshot = {when: award.When, snapshot: categoryTeamPoints}
yield snapshot
}
}
}
/**
* A MOTH Server interface.
*
* This uses localStorage to remember Team ID,
* and will send a Team ID with every request, if it can find one.
*/
class Server {
/**
* @param {string | URL} baseUrl Base URL to server, for constructing API URLs
*/
constructor(baseUrl) {
if (!baseUrl) {
throw("Must provide baseURL")
}
this.baseUrl = new URL(baseUrl, location)
this.teamIDKey = this.baseUrl.toString() + " teamID"
this.TeamID = localStorage[this.teamIDKey]
}
/**
* Fetch a MOTH resource.
*
* If anything other than a 2xx code is returned,
* this function throws an error.
*
* This always sends teamID.
* If args is set, POST will be used instead of GET
*
* @param {string} path Path to API endpoint
* @param {Object.<string,string>} args Key/Values to send in POST data
* @returns {Promise.<Response>} Response
*/
fetch(path, args={}) {
let body = new URLSearchParams(args)
if (this.TeamID && !body.has("id")) {
body.set("id", this.TeamID)
}
let url = new URL(path, this.baseUrl)
return fetch(url, {
method: "POST",
body,
})
}
/**
* Send a request to a JSend API endpoint.
*
* @param {string} path Path to API endpoint
* @param {Object.<string,string>} args Key/Values to send in POST
* @returns {Promise.<Object>} JSend Data
*/
async call(path, args={}) {
let resp = await this.fetch(path, args)
let obj = await resp.json()
switch (obj.status) {
case "success":
return obj.data
case "fail":
throw new Error(obj.data.description || obj.data.short || obj.data)
case "error":
throw new Error(obj.message)
default:
throw new Error(`Unknown JSend status: ${obj.status}`)
}
}
/**
* Make a new URL for the given resource.
*
* The returned URL instance will be absolute, and immune to changes to the
* page that would affect relative URLs.
*
* @returns {URL}
*/
URL(url) {
return new URL(url, this.baseUrl)
}
/**
* Are we logged in to the server?
*
* @returns {boolean}
*/
LoggedIn() {
return this.TeamID ? true : false
}
/**
* Forget about any previous Team ID.
*
* This is equivalent to logging out.
*/
Reset() {
localStorage.removeItem(this.teamIDKey)
this.TeamID = null
}
/**
* Fetch current contest state.
*
* @returns {Promise.<State>}
*/
async GetState() {
let resp = await this.fetch("/state")
let obj = await resp.json()
return new State(this, obj)
}
/**
* Log in to a team.
*
* This calls the server's registration endpoint; if the call succeds, or
* fails with "team already exists", the login is returned as successful.
*
* @param {string} teamID
* @param {string} teamName
* @returns {Promise.<string>} Success message from server
*/
async Login(teamID, teamName) {
let data = await this.call("/register", {id: teamID, name: teamName})
this.TeamID = teamID
this.TeamName = teamName
localStorage[this.teamIDKey] = teamID
return data.description || data.short
}
/**
* Submit a proposed answer for points.
*
* The returned promise will fail if anything goes wrong, including the
* proposed answer being rejected.
*
* @param {string} category Category of puzzle
* @param {number} points Point value of puzzle
* @param {string} proposed Answer to submit
* @returns {Promise.<string>} Success message
*/
async SubmitAnswer(category, points, proposed) {
let data = await this.call("/answer", {
cat: category,
points,
answer: proposed,
})
return data.description || data.short
}
/**
* Fetch a file associated with a puzzle.
*
* @param {string} category Category of puzzle
* @param {number} points Point value of puzzle
* @param {string} filename
* @returns {Promise.<Response>}
*/
GetContent(category, points, filename) {
return this.fetch(`/content/${category}/${points}/${filename}`)
}
/**
* Return a Puzzle object.
*
* New Puzzle objects only know their category and point value.
* See docstrings on the Puzzle object for more information.
*
* @param {string} category
* @param {number} points
* @returns {Puzzle}
*/
GetPuzzle(category, points) {
return new Puzzle(this, category, points)
}
}
export {
Hash,
Server,
}