From 9a33498fed26a8df9c9f35f39a78a174bf50a513 Mon Sep 17 00:00:00 2001 From: n1474335 Date: Wed, 28 Jul 2021 14:32:39 +0100 Subject: [PATCH] Added 'TLS JA3 Fingerprint' operation --- src/core/config/Categories.json | 1 + src/core/operations/TLSJA3Fingerprint.mjs | 198 +++++++++++++++++++ tests/operations/index.mjs | 1 + tests/operations/tests/TLSJA3Fingerprint.mjs | 55 ++++++ 4 files changed, 255 insertions(+) create mode 100644 src/core/operations/TLSJA3Fingerprint.mjs create mode 100644 tests/operations/tests/TLSJA3Fingerprint.mjs diff --git a/src/core/config/Categories.json b/src/core/config/Categories.json index 95e5870e5..ff472caf1 100755 --- a/src/core/config/Categories.json +++ b/src/core/config/Categories.json @@ -193,6 +193,7 @@ "Protobuf Decode", "VarInt Encode", "VarInt Decode", + "TLS JA3 Fingerprint", "Format MAC addresses", "Change IP format", "Group IP addresses", diff --git a/src/core/operations/TLSJA3Fingerprint.mjs b/src/core/operations/TLSJA3Fingerprint.mjs new file mode 100644 index 000000000..119bdac52 --- /dev/null +++ b/src/core/operations/TLSJA3Fingerprint.mjs @@ -0,0 +1,198 @@ +/** + * @author n1474335 [n1474335@gmail.com] + * @copyright Crown Copyright 2021 + * @license Apache-2.0 + */ + +import Operation from "../Operation.mjs"; +import OperationError from "../errors/OperationError.mjs"; +import Utils from "../Utils.mjs"; +import Stream from "../lib/Stream.mjs"; +import {runHash} from "../lib/Hash.mjs"; + +/** + * TLS JA3 Fingerprint operation + */ +class TLSJA3Fingerprint extends Operation { + + /** + * TLSJA3Fingerprint constructor + */ + constructor() { + super(); + + this.name = "TLS JA3 Fingerprint"; + this.module = "Crypto"; + this.description = "Generates a JA3 fingerprint to help identify TLS clients based on hashing together values from the Client Hello.

Input: A hex stream of the TLS Client Hello application layer."; + this.infoURL = "https://engineering.salesforce.com/tls-fingerprinting-with-ja3-and-ja3s-247362855967"; + this.inputType = "string"; + this.outputType = "string"; + this.args = [ + { + name: "Input format", + type: "option", + value: ["Hex", "Base64", "Raw"] + }, + { + name: "Output format", + type: "option", + value: ["Hash digest", "JA3 string", "Full details"] + } + ]; + } + + /** + * @param {string} input + * @param {Object[]} args + * @returns {string} + */ + run(input, args) { + const [inputFormat, outputFormat] = args; + + input = Utils.convertToByteArray(input, inputFormat); + const s = new Stream(new Uint8Array(input)); + + const handshake = s.readInt(1); + if (handshake !== 0x16) + throw new OperationError("Not handshake data."); + + // Version + s.moveForwardsBy(2); + + // Length + const length = s.readInt(2); + if (s.length !== length + 5) + throw new OperationError("Incorrect handshake length."); + + // Handshake type + const handshakeType = s.readInt(1); + if (handshakeType !== 1) + throw new OperationError("Not a Client Hello."); + + // Handshake length + const handshakeLength = s.readInt(3); + if (s.length !== handshakeLength + 9) + throw new OperationError("Not enough data in Client Hello."); + + // Hello version + const helloVersion = s.readInt(2); + + // Random + s.moveForwardsBy(32); + + // Session ID + const sessionIDLength = s.readInt(1); + s.moveForwardsBy(sessionIDLength); + + // Cipher suites + const cipherSuitesLength = s.readInt(2); + const cipherSuites = s.getBytes(cipherSuitesLength); + const cs = new Stream(cipherSuites); + const cipherSegment = parseJA3Segment(cs, 2); + + // Compression Methods + const compressionMethodsLength = s.readInt(1); + s.moveForwardsBy(compressionMethodsLength); + + // Extensions + const extensionsLength = s.readInt(2); + const extensions = s.getBytes(extensionsLength); + const es = new Stream(extensions); + let ecsLen, ecs, ellipticCurves = "", ellipticCurvePointFormats = ""; + const exts = []; + while (es.hasMore()) { + const type = es.readInt(2); + const length = es.readInt(2); + switch (type) { + case 0x0a: // Elliptic curves + ecsLen = es.readInt(2); + ecs = new Stream(es.getBytes(ecsLen)); + ellipticCurves = parseJA3Segment(ecs, 2); + break; + case 0x0b: // Elliptic curve point formats + ecsLen = es.readInt(1); + ecs = new Stream(es.getBytes(ecsLen)); + ellipticCurvePointFormats = parseJA3Segment(ecs, 1); + break; + default: + es.moveForwardsBy(length); + } + if (!GREASE_CIPHERSUITES.includes(type)) + exts.push(type); + } + + // Output + const ja3 = [ + helloVersion.toString(), + cipherSegment, + exts.join("-"), + ellipticCurves, + ellipticCurvePointFormats + ]; + const ja3Str = ja3.join(","); + const ja3Hash = runHash("md5", Utils.strToArrayBuffer(ja3Str)); + + switch (outputFormat) { + case "JA3 string": + return ja3Str; + case "Full details": + return `Hash digest: +${ja3Hash} + +Full JA3 string: +${ja3Str} + +TLS Version: +${helloVersion.toString()} +Cipher Suites: +${cipherSegment} +Extensions: +${exts.join("-")} +Elliptic Curves: +${ellipticCurves} +Elliptic Curve Point Formats: +${ellipticCurvePointFormats}`; + case "Hash digest": + default: + return ja3Hash; + } + } + +} + +/** + * Parses a JA3 segment, returning a "-" separated list + * + * @param {Stream} stream + * @returns {string} + */ +function parseJA3Segment(stream, size=2) { + const segment = []; + while (stream.hasMore()) { + const element = stream.readInt(size); + if (!GREASE_CIPHERSUITES.includes(element)) + segment.push(element); + } + return segment.join("-"); +} + +const GREASE_CIPHERSUITES = [ + 0x0a0a, + 0x1a1a, + 0x2a2a, + 0x3a3a, + 0x4a4a, + 0x5a5a, + 0x6a6a, + 0x7a7a, + 0x8a8a, + 0x9a9a, + 0xaaaa, + 0xbaba, + 0xcaca, + 0xdada, + 0xeaea, + 0xfafa +]; + +export default TLSJA3Fingerprint; diff --git a/tests/operations/index.mjs b/tests/operations/index.mjs index f2225fc6d..fdce51317 100644 --- a/tests/operations/index.mjs +++ b/tests/operations/index.mjs @@ -104,6 +104,7 @@ import "./tests/Unicode.mjs"; import "./tests/RSA.mjs"; import "./tests/CBOREncode.mjs"; import "./tests/CBORDecode.mjs"; +import "./tests/TLSJA3Fingerprint.mjs"; // Cannot test operations that use the File type yet diff --git a/tests/operations/tests/TLSJA3Fingerprint.mjs b/tests/operations/tests/TLSJA3Fingerprint.mjs new file mode 100644 index 000000000..4f1534fb9 --- /dev/null +++ b/tests/operations/tests/TLSJA3Fingerprint.mjs @@ -0,0 +1,55 @@ +/** + * TLSJA3Fingerprint tests. + * + * @author n1474335 [n1474335@gmail.com] + * @copyright Crown Copyright 2021 + * @license Apache-2.0 + */ +import TestRegister from "../../lib/TestRegister.mjs"; + +TestRegister.addTests([ + { + name: "TLS JA3 Fingerprint: TLS 1.0", + input: "16030100a4010000a00301543dd2dd48f517ca9a93b1e599f019fdece704a23e86c1dcac588427abbaddf200005cc014c00a0039003800880087c00fc00500350084c012c00800160013c00dc003000ac013c00900330032009a009900450044c00ec004002f009600410007c011c007c00cc002000500040015001200090014001100080006000300ff0100001b000b000403000102000a000600040018001700230000000f000101", + expectedOutput: "503053a0c5b2bd9b9334bf7f3d3b8852", + recipeConfig: [ + { + "op": "TLS JA3 Fingerprint", + "args": ["Hex", "Hash digest"] + } + ], + }, + { + name: "TLS JA3 Fingerprint: TLS 1.1", + input: "16030100a4010000a00302543dd2ed907e47d0086f34bee2c52dd6ccd8de63ba9387f5e810b09d9d49b38000005cc014c00a0039003800880087c00fc00500350084c012c00800160013c00dc003000ac013c00900330032009a009900450044c00ec004002f009600410007c011c007c00cc002000500040015001200090014001100080006000300ff0100001b000b000403000102000a000600040018001700230000000f000101", + expectedOutput: "a314eb64cee6cb832aaaa372c8295bab", + recipeConfig: [ + { + "op": "TLS JA3 Fingerprint", + "args": ["Hex", "Hash digest"] + } + ], + }, + { + name: "TLS JA3 Fingerprint: TLS 1.2", + input: "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", + expectedOutput: "c1a36e1a870786cc75edddc0009eaf3a", + recipeConfig: [ + { + "op": "TLS JA3 Fingerprint", + "args": ["Hex", "Hash digest"] + } + ], + }, + { + name: "TLS JA3 Fingerprint: TLS 1.3", + input: "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", + expectedOutput: "4826a90ec2daf4f7b4b64cc1c8bd343b", + recipeConfig: [ + { + "op": "TLS JA3 Fingerprint", + "args": ["Hex", "Hash digest"] + } + ], + }, +]);