CODEWITHSUNDEEP
node.jsflutterdart
Meet Parsaniya
Meet Parsaniya

Reputation: 63

Flutter: Hmac Crypto Package

I'm trying to take the process of converting a secret hmac string. Code on node.js and Dart doe not give same result.

Dart Code:

String credentials = "031f0b737d155ed67bb9a3a174e10f6e";
      String stringForTokenGeneration = "/627b533efd2da43909008561/63bfe56832156f9174527aa6?expires=1674823949447";
      Codec<String, String> stringToBase64 = utf8.fuse(base64);
      String encoded = stringToBase64.encode(credentials);
      // String decoded = stringToBase64.decode(encoded);


      var key = utf8.encode(encoded);
      var bytes = utf8.encode(stringForTokenGeneration);

      var hmacSha1 = Hmac(sha1, key); // HMAC-SHA256
      var digest = hmacSha1.convert(bytes);
      _counter=" $digest";

      print("HMAC digest as bytes: ${digest.bytes}");
      print("HMAC digest as hex string: $digest");

nodejs Code

const crypto = require('crypto');

let proxySecret = "031f0b737d155ed67bb9a3a174e10f6e";


proxySecret = Buffer.from(proxySecret, 'base64');


let stringForTokenGeneration = '/627b533efd2da43909008561/63bfe56832156f9174527aa6?expires=1674823949447';

console.log(`string For Token Generation: ${stringForTokenGeneration}`);

let signature = crypto.createHmac('sha1', proxySecret).update(stringForTokenGeneration).digest('hex');

console.log(`Auth Token: ${signature}`);

I want Dart code to return same signature as node

Upvotes: 0

Views: 304

Answers (1)

Richard Heap
Richard Heap

Reputation: 51751

It looks like you are just missing the conversion to hex at the end. The hex codec is in package:convert which you will need to add to your pubspec.yaml.

Here it is using pointycastle but will likely work with hmac from package:crypto too.

import 'dart:convert';
import 'dart:typed_data';

import 'package:pointycastle/export.dart';
import 'package:convert/convert.dart';

void main() {
  final credentials = '031f0b737d155ed67bb9a3a174e10f6e';
  final forTokenGeneration =
      '/627b533efd2da43909008561/63bfe56832156f9174527aa6?expires=1674823949447';

  final hmac = HMac(SHA1Digest(), 64)
    ..init(KeyParameter(base64.decode(credentials)));
  final sigBytes = hmac.process(utf8.encode(forTokenGeneration) as Uint8List);
  final signature = hex.encode(sigBytes);

  print(signature); // 7dead8b06e017b9727cb52f5bf36665d840a8126
}

Upvotes: 1

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