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| 1 | +<!DOCTYPE html> |
| 2 | +<html lang="en"><head><title></title><script> |
| 3 | +class BotGuardClient { |
| 4 | + constructor(options) { |
| 5 | + this.userInteractionElement = options.userInteractionElement; |
| 6 | + this.vm = options.globalObj[options.globalName]; |
| 7 | + this.program = options.program; |
| 8 | + this.vmFunctions = {}; |
| 9 | + this.syncSnapshotFunction = null; |
| 10 | + } |
| 11 | + |
| 12 | + /** |
| 13 | + * Factory method to create and load a BotGuardClient instance. |
| 14 | + * @param options - Configuration options for the BotGuardClient. |
| 15 | + * @returns A promise that resolves to a loaded BotGuardClient instance. |
| 16 | + */ |
| 17 | + static async create(options) { |
| 18 | + return await new BotGuardClient(options).load(); |
| 19 | + } |
| 20 | + |
| 21 | + async load() { |
| 22 | + if (!this.vm) |
| 23 | + throw new Error('[BotGuardClient]: VM not found in the global object'); |
| 24 | + |
| 25 | + if (!this.vm.a) |
| 26 | + throw new Error('[BotGuardClient]: Could not load program'); |
| 27 | + |
| 28 | + const vmFunctionsCallback = ( |
| 29 | + asyncSnapshotFunction, |
| 30 | + shutdownFunction, |
| 31 | + passEventFunction, |
| 32 | + checkCameraFunction |
| 33 | + ) => { |
| 34 | + this.vmFunctions = { |
| 35 | + asyncSnapshotFunction: asyncSnapshotFunction, |
| 36 | + shutdownFunction: shutdownFunction, |
| 37 | + passEventFunction: passEventFunction, |
| 38 | + checkCameraFunction: checkCameraFunction |
| 39 | + }; |
| 40 | + }; |
| 41 | + |
| 42 | + try { |
| 43 | + this.syncSnapshotFunction = await this.vm.a(this.program, vmFunctionsCallback, true, this.userInteractionElement, () => {/** no-op */ }, [ [], [] ])[0]; |
| 44 | + } catch (error) { |
| 45 | + throw new Error(`[BotGuardClient]: Failed to load program (${error.message})`); |
| 46 | + } |
| 47 | + |
| 48 | + // an asynchronous function runs in the background and it will eventually call |
| 49 | + // `vmFunctionsCallback`, however we need to manually tell JavaScript to pass |
| 50 | + // control to the things running in the background by interrupting this async |
| 51 | + // function in any way, e.g. with a delay of 1ms. The loop is most probably not |
| 52 | + // needed but is there just because. |
| 53 | + for (let i = 0; i < 10000 && !this.vmFunctions.asyncSnapshotFunction; ++i) { |
| 54 | + await new Promise(f => setTimeout(f, 1)) |
| 55 | + } |
| 56 | + |
| 57 | + return this; |
| 58 | + } |
| 59 | + |
| 60 | + /** |
| 61 | + * Takes a snapshot asynchronously. |
| 62 | + * @returns The snapshot result. |
| 63 | + * @example |
| 64 | + * ```ts |
| 65 | + * const result = await botguard.snapshot({ |
| 66 | + * contentBinding: { |
| 67 | + * c: "a=6&a2=10&b=SZWDwKVIuixOp7Y4euGTgwckbJA&c=1729143849&d=1&t=7200&c1a=1&c6a=1&c6b=1&hh=HrMb5mRWTyxGJphDr0nW2Oxonh0_wl2BDqWuLHyeKLo", |
| 68 | + * e: "ENGAGEMENT_TYPE_VIDEO_LIKE", |
| 69 | + * encryptedVideoId: "P-vC09ZJcnM" |
| 70 | + * } |
| 71 | + * }); |
| 72 | + * |
| 73 | + * console.log(result); |
| 74 | + * ``` |
| 75 | + */ |
| 76 | + async snapshot(args) { |
| 77 | + return new Promise((resolve, reject) => { |
| 78 | + if (!this.vmFunctions.asyncSnapshotFunction) |
| 79 | + return reject(new Error('[BotGuardClient]: Async snapshot function not found')); |
| 80 | + |
| 81 | + this.vmFunctions.asyncSnapshotFunction((response) => resolve(response), [ |
| 82 | + args.contentBinding, |
| 83 | + args.signedTimestamp, |
| 84 | + args.webPoSignalOutput, |
| 85 | + args.skipPrivacyBuffer |
| 86 | + ]); |
| 87 | + }); |
| 88 | + } |
| 89 | +} |
| 90 | +/** |
| 91 | + * Parses the challenge data from the provided response data. |
| 92 | + */ |
| 93 | +function parseChallengeData(rawData) { |
| 94 | + let challengeData = []; |
| 95 | + |
| 96 | + if (rawData.length > 1 && typeof rawData[1] === 'string') { |
| 97 | + const descrambled = descramble(rawData[1]); |
| 98 | + challengeData = JSON.parse(descrambled || '[]'); |
| 99 | + } else if (rawData.length && typeof rawData[0] === 'object') { |
| 100 | + challengeData = rawData[0]; |
| 101 | + } |
| 102 | + |
| 103 | + const [ messageId, wrappedScript, wrappedUrl, interpreterHash, program, globalName, , clientExperimentsStateBlob ] = challengeData; |
| 104 | + |
| 105 | + const privateDoNotAccessOrElseSafeScriptWrappedValue = Array.isArray(wrappedScript) ? wrappedScript.find((value) => value && typeof value === 'string') : null; |
| 106 | + const privateDoNotAccessOrElseTrustedResourceUrlWrappedValue = Array.isArray(wrappedUrl) ? wrappedUrl.find((value) => value && typeof value === 'string') : null; |
| 107 | + |
| 108 | + return { |
| 109 | + messageId, |
| 110 | + interpreterJavascript: { |
| 111 | + privateDoNotAccessOrElseSafeScriptWrappedValue, |
| 112 | + privateDoNotAccessOrElseTrustedResourceUrlWrappedValue |
| 113 | + }, |
| 114 | + interpreterHash, |
| 115 | + program, |
| 116 | + globalName, |
| 117 | + clientExperimentsStateBlob |
| 118 | + }; |
| 119 | +} |
| 120 | + |
| 121 | +/** |
| 122 | + * Descrambles the given challenge data. |
| 123 | + */ |
| 124 | +function descramble(scrambledChallenge) { |
| 125 | + const buffer = base64ToU8(scrambledChallenge); |
| 126 | + if (buffer.length) |
| 127 | + return new TextDecoder().decode(buffer.map((b) => b + 97)); |
| 128 | +} |
| 129 | + |
| 130 | +const base64urlCharRegex = /[-_.]/g; |
| 131 | + |
| 132 | +const base64urlToBase64Map = { |
| 133 | + '-': '+', |
| 134 | + _: '/', |
| 135 | + '.': '=' |
| 136 | +}; |
| 137 | + |
| 138 | +function base64ToU8(base64) { |
| 139 | + let base64Mod; |
| 140 | + |
| 141 | + if (base64urlCharRegex.test(base64)) { |
| 142 | + base64Mod = base64.replace(base64urlCharRegex, function (match) { |
| 143 | + return base64urlToBase64Map[match]; |
| 144 | + }); |
| 145 | + } else { |
| 146 | + base64Mod = base64; |
| 147 | + } |
| 148 | + |
| 149 | + base64Mod = atob(base64Mod); |
| 150 | + |
| 151 | + return new Uint8Array( |
| 152 | + [ ...base64Mod ].map( |
| 153 | + (char) => char.charCodeAt(0) |
| 154 | + ) |
| 155 | + ); |
| 156 | +} |
| 157 | + |
| 158 | +function u8ToBase64(u8, base64url = false) { |
| 159 | + const result = btoa(String.fromCharCode(...u8)); |
| 160 | + |
| 161 | + if (base64url) { |
| 162 | + return result |
| 163 | + .replace(/\+/g, '-') |
| 164 | + .replace(/\//g, '_'); |
| 165 | + } |
| 166 | + |
| 167 | + return result; |
| 168 | +} |
| 169 | + |
| 170 | +async function runBotGuard(rawChallengeData) { |
| 171 | + const challengeData = parseChallengeData(rawChallengeData) |
| 172 | + const interpreterJavascript = challengeData.interpreterJavascript.privateDoNotAccessOrElseSafeScriptWrappedValue; |
| 173 | + |
| 174 | + if (interpreterJavascript) { |
| 175 | + new Function(interpreterJavascript)(); |
| 176 | + } else throw new Error('Could not load VM'); |
| 177 | + |
| 178 | + const botguard = await BotGuardClient.create({ |
| 179 | + globalName: challengeData.globalName, |
| 180 | + globalObj: globalThis, |
| 181 | + program: challengeData.program |
| 182 | + }); |
| 183 | + |
| 184 | + const webPoSignalOutput = []; |
| 185 | + const botguardResponse = await botguard.snapshot({ webPoSignalOutput }); |
| 186 | + return { webPoSignalOutput, botguardResponse } |
| 187 | +} |
| 188 | + |
| 189 | +async function obtainPoToken(webPoSignalOutput, integrityTokenResponse, identifier) { |
| 190 | + const integrityToken = integrityTokenResponse[0]; |
| 191 | + const getMinter = webPoSignalOutput[0]; |
| 192 | + |
| 193 | + if (!getMinter) |
| 194 | + throw new Error('PMD:Undefined'); |
| 195 | + |
| 196 | + const mintCallback = await getMinter(base64ToU8(integrityToken)); |
| 197 | + |
| 198 | + if (!(mintCallback instanceof Function)) |
| 199 | + throw new Error('APF:Failed'); |
| 200 | + |
| 201 | + const result = await mintCallback(new TextEncoder().encode(identifier)); |
| 202 | + |
| 203 | + if (!result) |
| 204 | + throw new Error('YNJ:Undefined'); |
| 205 | + |
| 206 | + if (!(result instanceof Uint8Array)) |
| 207 | + throw new Error('ODM:Invalid'); |
| 208 | + |
| 209 | + return u8ToBase64(result, true); |
| 210 | +} |
| 211 | +</script></head><body></body></html> |
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