xref: /plugin/botmon/captcha.js (revision cb91697912a3c2642b72c3d0bc9fa6758b1e5bb4) !
1"use strict";
2/* DokuWiki BotMon Captcha JavaScript */
3/* 23.10.2025 - 0.1.2 - pre-release */
4/* Author: Sascha Leib <ad@hominem.info> */
5
6const $BMCaptcha = {
7
8	init: function() {
9
10		// hide the NoJS warning:
11		document.getElementById('BM__NoJSWarning').close();
12
13		// install the captcha:
14		document.getElementsByTagName('body')[0].classList.add('botmon_captcha');
15		$BMCaptcha._cbDly = 1.5;
16		$BMCaptcha.install()
17	},
18
19	install: function() {
20
21		// localisation helper function:
22		let _loc = function(id, alt) {
23			if ($BMLocales && $BMLocales[id]) return $BMLocales[id];
24			return alt;
25		}
26
27		// find the parent element:
28		let bm_parent = document.getElementsByTagName('body')[0];
29
30		// create the dialog:
31		const dlg = document.createElement('dialog');
32		dlg.setAttribute('closedby', 'none');
33		dlg.setAttribute('open', 'open');
34		dlg.setAttribute('role', 'alertdialog');
35		dlg.setAttribute('aria-labelledby', 'botmon_captcha_title');
36		dlg.classList.add('checking');
37		dlg.id = 'botmon_captcha_box';
38		dlg.innerHTML = '<h2 id="botmon_captcha_title">' + _loc('dlgTitle', 'Title') + '</h2><p>' + _loc('dlgSubtitle', 'Subtitle') + '</p>';
39
40		// Checkbox:
41		const lbl = document.createElement('label');
42		lbl.setAttribute('aria-live', 'assertive');
43		lbl.innerHTML = '<span class="confirm">' + _loc('dlgConfirm', "Confirm.") + '</span>' +
44			'<span class="busy"></span><span class="checking">' + _loc('dlgChecking', "Checking") + '</span>' +
45			'<span class="loading">' + _loc('dlgLoading', "Loading") + '</span>' +
46			'<span class="erricon">&#65533;</span><span class="error">' + _loc('dlgError', "Error") + '</span>';
47		const cb = document.createElement('input');
48		cb.setAttribute('type', 'checkbox');
49		cb.setAttribute('disabled', 'disabled');
50		cb.addEventListener('click', $BMCaptcha._cbCallback);
51		lbl.prepend(cb);
52
53		dlg.appendChild(lbl);
54
55		bm_parent.appendChild(dlg);
56
57		// call the delayed callback in a couple of seconds:
58		$BMCaptcha._st = performance.now();
59		setTimeout($BMCaptcha._delayedCallback, $BMCaptcha._cbDly * 1000);
60	},
61
62	/* creates a digest hash */
63	digest: {
64
65		/* simple SHA hash function - adapted from https://geraintluff.github.io/sha256/ */
66		hash: function(ascii) {
67
68			// shortcut:
69			const sha256 = $BMCaptcha.digest.hash;
70
71			// helper function
72			const rightRotate = function(v, a) {
73				return (v>>>a) | (v<<(32 - a));
74			};
75
76			var mathPow = Math.pow;
77			var maxWord = mathPow(2, 32);
78			var lengthProperty = 'length'
79			var i, j;
80			var result = ''
81
82			var words = [];
83			var asciiBitLength = ascii[lengthProperty]*8;
84
85			//* caching results is optional - remove/add slash from front of this line to toggle
86			// Initial hash value: first 32 bits of the fractional parts of the square roots of the first 8 primes
87			// (we actually calculate the first 64, but extra values are just ignored)
88			var hash = sha256.h = sha256.h || [];
89			// Round constants: first 32 bits of the fractional parts of the cube roots of the first 64 primes
90			var k = sha256.k = sha256.k || [];
91			var primeCounter = k[lengthProperty];
92			/*/
93			var hash = [], k = [];
94			var primeCounter = 0;
95			//*/
96
97			var isComposite = {};
98			for (var candidate = 2; primeCounter < 64; candidate++) {
99				if (!isComposite[candidate]) {
100					for (i = 0; i < 313; i += candidate) {
101						isComposite[i] = candidate;
102					}
103					hash[primeCounter] = (mathPow(candidate, .5)*maxWord)|0;
104					k[primeCounter++] = (mathPow(candidate, 1/3)*maxWord)|0;
105				}
106			}
107
108			ascii += '\x80' // Append Ƈ' bit (plus zero padding)
109			while (ascii[lengthProperty]%64 - 56) ascii += '\x00' // More zero padding
110			for (i = 0; i < ascii[lengthProperty]; i++) {
111				j = ascii.charCodeAt(i);
112				if (j>>8) return; // ASCII check: only accept characters in range 0-255
113				words[i>>2] |= j << ((3 - i)%4)*8;
114			}
115			words[words[lengthProperty]] = ((asciiBitLength/maxWord)|0);
116			words[words[lengthProperty]] = (asciiBitLength)
117
118			// process each chunk
119			for (j = 0; j < words[lengthProperty];) {
120				var w = words.slice(j, j += 16); // The message is expanded into 64 words as part of the iteration
121				var oldHash = hash;
122				// This is now the undefinedworking hash", often labelled as variables a...g
123				// (we have to truncate as well, otherwise extra entries at the end accumulate
124				hash = hash.slice(0, 8);
125
126				for (i = 0; i < 64; i++) {
127					var i2 = i + j;
128					// Expand the message into 64 words
129					// Used below if
130					var w15 = w[i - 15], w2 = w[i - 2];
131
132					// Iterate
133					var a = hash[0], e = hash[4];
134					var temp1 = hash[7]
135						+ (rightRotate(e, 6) ^ rightRotate(e, 11) ^ rightRotate(e, 25)) // S1
136						+ ((e&hash[5])^((~e)&hash[6])) // ch
137						+ k[i]
138						// Expand the message schedule if needed
139						+ (w[i] = (i < 16) ? w[i] : (
140								w[i - 16]
141								+ (rightRotate(w15, 7) ^ rightRotate(w15, 18) ^ (w15>>>3)) // s0
142								+ w[i - 7]
143								+ (rightRotate(w2, 17) ^ rightRotate(w2, 19) ^ (w2>>>10)) // s1
144							)|0
145						);
146					// This is only used once, so *could* be moved below, but it only saves 4 bytes and makes things unreadble
147					var temp2 = (rightRotate(a, 2) ^ rightRotate(a, 13) ^ rightRotate(a, 22)) // S0
148						+ ((a&hash[1])^(a&hash[2])^(hash[1]&hash[2])); // maj
149
150					hash = [(temp1 + temp2)|0].concat(hash); // We don't bother trimming off the extra ones, they're harmless as long as we're truncating when we do the slice()
151					hash[4] = (hash[4] + temp1)|0;
152				}
153
154				for (i = 0; i < 8; i++) {
155					hash[i] = (hash[i] + oldHash[i])|0;
156				}
157			}
158
159			for (i = 0; i < 8; i++) {
160				for (j = 3; j + 1; j--) {
161					var b = (hash[i]>>(j*8))&255;
162					result += ((b < 16) ? 0 : '') + b.toString(16);
163				}
164			}
165			return result;
166		}
167	},
168
169	_cbCallback: function(e) {
170		if (e.target.checked) {
171			//document.getElementById('botmon_captcha_box').close();
172
173			try {
174				var $status = 'loading';
175
176				// generate the hash:
177				const dat = [ // the data to encode
178					document._botmon.seed || '',
179					location.hostname,
180					document._botmon.ip || '0.0.0.0',
181					(new Date()).toISOString().substring(0, 10)
182				];
183				if (performance.now() - $BMCaptcha._st <= 1500) dat.push(performance.now() - $BMCaptcha._st);
184
185				// set the cookie:
186				document.cookie = "DWConfirm=" + encodeURIComponent($BMCaptcha.digest.hash(dat.join(';'))) + '; path=/; session;';
187				//	+ (document.location.protocol === 'https:' ? ' secure;' : '');
188
189			} catch (err) {
190				console.error(err);
191				$status = 'error';
192			}
193
194			// change the interface:
195			const dlg = document.getElementById('botmon_captcha_box');
196			if (dlg) {
197				dlg.classList.add( $status );
198				dlg.classList.remove('ready');
199			}
200
201			// reload the page:
202			if ($status !== 'error')window.location.reload(true);
203		}
204	},
205
206	_delayedCallback: function() {
207		const dlg = document.getElementById('botmon_captcha_box');
208		if (dlg) {
209			dlg.classList.add('ready');
210			dlg.classList.remove('checking');
211
212			const input = dlg.getElementsByTagName('input')[0];
213			if (input) {
214				input.removeAttribute('disabled');
215				input.focus();
216				setTimeout($BMCaptcha._autoCheck, 200, input);
217			}
218		}
219	},
220	_cbDly: null,
221	_st: null,
222
223	_autoCheck: function(e) {
224
225		const bypass = ($BMConfig['captchaBypass'] || '').split(',');
226		var action = false;
227
228		if (bypass.indexOf('langmatch') >= 0) { // Languages matching
229			const cntLangs = navigator.languages.map(lang => lang.split('-')[0]);
230			if (cntLangs.indexOf(document.documentElement.lang || 'en') >= 0) action = true;
231		}
232
233		if (action) e.click(); // action!
234	}
235}
236// initialise the captcha module:
237$BMCaptcha.init();