121 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			JavaScript
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			121 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			JavaScript
		
	
	
		
			Executable File
		
	
	
	
	
| /*global module*/
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| var Buffer = require('safe-buffer').Buffer;
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| var DataStream = require('./data-stream');
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| var jwa = require('jwa');
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| var Stream = require('stream');
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| var toString = require('./tostring');
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| var util = require('util');
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| var JWS_REGEX = /^[a-zA-Z0-9\-_]+?\.[a-zA-Z0-9\-_]+?\.([a-zA-Z0-9\-_]+)?$/;
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| 
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| function isObject(thing) {
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|   return Object.prototype.toString.call(thing) === '[object Object]';
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| }
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| 
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| function safeJsonParse(thing) {
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|   if (isObject(thing))
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|     return thing;
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|   try { return JSON.parse(thing); }
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|   catch (e) { return undefined; }
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| }
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| 
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| function headerFromJWS(jwsSig) {
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|   var encodedHeader = jwsSig.split('.', 1)[0];
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|   return safeJsonParse(Buffer.from(encodedHeader, 'base64').toString('binary'));
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| }
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| 
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| function securedInputFromJWS(jwsSig) {
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|   return jwsSig.split('.', 2).join('.');
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| }
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| 
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| function signatureFromJWS(jwsSig) {
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|   return jwsSig.split('.')[2];
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| }
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| 
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| function payloadFromJWS(jwsSig, encoding) {
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|   encoding = encoding || 'utf8';
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|   var payload = jwsSig.split('.')[1];
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|   return Buffer.from(payload, 'base64').toString(encoding);
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| }
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| 
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| function isValidJws(string) {
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|   return JWS_REGEX.test(string) && !!headerFromJWS(string);
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| }
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| 
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| function jwsVerify(jwsSig, algorithm, secretOrKey) {
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|   if (!algorithm) {
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|     var err = new Error("Missing algorithm parameter for jws.verify");
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|     err.code = "MISSING_ALGORITHM";
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|     throw err;
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|   }
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|   jwsSig = toString(jwsSig);
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|   var signature = signatureFromJWS(jwsSig);
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|   var securedInput = securedInputFromJWS(jwsSig);
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|   var algo = jwa(algorithm);
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|   return algo.verify(securedInput, signature, secretOrKey);
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| }
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| 
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| function jwsDecode(jwsSig, opts) {
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|   opts = opts || {};
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|   jwsSig = toString(jwsSig);
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| 
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|   if (!isValidJws(jwsSig))
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|     return null;
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| 
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|   var header = headerFromJWS(jwsSig);
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| 
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|   if (!header)
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|     return null;
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| 
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|   var payload = payloadFromJWS(jwsSig);
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|   if (header.typ === 'JWT' || opts.json)
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|     payload = JSON.parse(payload, opts.encoding);
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| 
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|   return {
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|     header: header,
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|     payload: payload,
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|     signature: signatureFromJWS(jwsSig)
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|   };
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| }
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| 
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| function VerifyStream(opts) {
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|   opts = opts || {};
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|   var secretOrKey = opts.secret||opts.publicKey||opts.key;
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|   var secretStream = new DataStream(secretOrKey);
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|   this.readable = true;
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|   this.algorithm = opts.algorithm;
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|   this.encoding = opts.encoding;
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|   this.secret = this.publicKey = this.key = secretStream;
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|   this.signature = new DataStream(opts.signature);
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|   this.secret.once('close', function () {
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|     if (!this.signature.writable && this.readable)
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|       this.verify();
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|   }.bind(this));
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| 
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|   this.signature.once('close', function () {
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|     if (!this.secret.writable && this.readable)
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|       this.verify();
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|   }.bind(this));
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| }
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| util.inherits(VerifyStream, Stream);
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| VerifyStream.prototype.verify = function verify() {
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|   try {
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|     var valid = jwsVerify(this.signature.buffer, this.algorithm, this.key.buffer);
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|     var obj = jwsDecode(this.signature.buffer, this.encoding);
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|     this.emit('done', valid, obj);
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|     this.emit('data', valid);
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|     this.emit('end');
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|     this.readable = false;
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|     return valid;
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|   } catch (e) {
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|     this.readable = false;
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|     this.emit('error', e);
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|     this.emit('close');
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|   }
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| };
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| 
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| VerifyStream.decode = jwsDecode;
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| VerifyStream.isValid = isValidJws;
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| VerifyStream.verify = jwsVerify;
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| 
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| module.exports = VerifyStream;
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