when downloading certficate binary data , result is invalid certificate

Question

I'm receiving binary data in php as certificate content and I want to download it to browser . I'm getting this message always when opening it with certificate viewer :

hex(19).pfx
Could not display 'hex(19).pfx'
Reason:   Unrecognized or unsupported data.

this binary data is correct , I put it in a file on the server immediately and it made a valid certificate .

I think the problem is in two where :

• output of command

  exec('ssh root@192.168.0.137 "echo '.$bindata.' | xxd -p -r | tr -d \'\n\' "',$output);

while $bindata is coming from converting certificate pfx file after making it in bash with xxd -p

• or it's in the header , there is a lost or addition :

  header("Content-Description: File Transfer");
  header("Content-Type: application/octet-stream");
  header("Content-Transfer-Encoding: binary");
  header("Content-Disposition: attachment; filename=hex.pfx");
  header('Content-Length: '.  strlen($output[0]));
  header('Expires: 0');
  header('Cache-Control: must-revalidate');
  header('Pragma: public');
  echo $output[0];
  exit();
  

  what's the wrong ?

Answer 1

solution is to remove spaces of the output of xxd

in bash :

res=`xxd -p $exportedkey`
echo "${res//[[:space:]]/}"

in php :

$hex = hex2bin($result);
header("Content-Description: File Transfer");
header("Content-Type: application/octet-stream");
header("Content-Transfer-Encoding: binary");
header("Content-Disposition: attachment; filename=hex.pfx");
header('Content-Length: '.  strlen($hex));
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');

echo $hex;
exit(); 

hope it helps at least someone