Google身份验证器扫描时无效的条形码

Question

here's my code in generating the qr code

public function getUrl($user, $hostname, $secret) {
      $encoder = "https://chart.googleapis.com/chart?chs=200x200&chld=M%70&cht=qr&chl=";
      $encoderURL = sprintf( "%sotpauth://totp/%s@%s",$encoder, $user, $hostname);
      $finalEncodorURL = $encoderURL . "%26secret=". urlencode($secret);
      return $finalEncodorURL;
}

supposedly this will generate a qr code, and it does. but when i scan this code using google authenticator app, it will generate an error

The barcode 'otpauth://totp/[e-mail]&secret=UOPKN6QFW3J6PW74' is not a valid authentication barcode.

but when "manual entry" using the secret key, it'll work and i can login just fine using the generated key.

i found stuffs in the internet saying i should urlencode the data, i did, but still it wont work.

here's a sample url generated by the function above:

https://chart.googleapis.com/chart?chs=200x200&chld=M%70&cht=qr&chl=otpauth://totp/[e-mail]%26secret=UOPKN6QFW3J6PW74

am i missing something or did something wrong?

Answer 1

You should fully URL encode the data that you pass to the charts API.

otpauth%3A%2F%2Ftotp%2Fuser4%40noemail.com%26secret%3DUOPKN6QFW3J6PW74

That should ensure that the data is encoded properly.