When I run exec command in php script , it is not giving any output but return value is 0

When I run an exec command in my php script, it is not giving any output but return value is 0

Background : I am trying to implement AS2 communication functionality using AS2Secure PHP code. When I am trying to send message to partner after signing and encrypting. But at the time of encrypting , it is not encrypting , we are sending only signed message.

Here is the exec command function:

openssl smime  -encrypt -in "C:\Users\Maggy\AppData\Local\Temp\as2A5B3.tmp" -out "C:\Users\Maggy\AppData\Local\Temp\as2B18B.tmp" -des3 "D:\as2secure_code_build-0.9.0\partners\maggy\clientcertificate.pem"

I ran the the same command in the command line and it is successfully giving output.

Here is the PHP code:

    public static function exec($command, $return_output = false){
        $output = array();
        $return_var = 0;
        try{

    AS2Log::info(false, 'This is AS2Adapter File and IN EXEC FUNCTION CALLED'.$command);
    // AS2Log::info(false, 'INPUT DATA as FOLLOWS'.file_get_contents($input));
            exec($command , $output, $return_var);
    //          proc_open($command , $output, $return_var);
    //            passthru ("$command , 2>&1");
    AS2Log::info(false, 'This is AS2Adapter File and IN EXEC FUNCTION EXECUTED and Result will             
    be ~~~~~~~~~~~~~~~~~~~~~');


    AS2Log::info(false, 'This is AS2Adapter File and IN EXEC FUNCTION COMPLETED                         
    SUCCESSFULLY'.$output[0]);

    $line = (isset($output[0])?$output[0]:'Unexpected error in command line : ' . $command);
            if ($return_var) throw new Exception($line, (int)$return_var);
        }
        catch(Exception $e){
            throw $e;
        }
        
    AS2Log::info(false, 'This is RETURN OUTPUT LOOKS LIKE : '.file_get_contents($output));

    AS2Log::info(false, 'This is RETURN VAR LOOKS LIKE : '.file_get_contents($return_var));

    if ($return_output){
        return $output;
    AS2Log::info(false, 'This is AS2Adapter File and FINAL OUTPUT LOOKS LIKE : '.$output);

    }
    else
        return $return_var;
    }

Can you please help me resolve this issue?

I have tried shell_exec and it is giving the same result.

I have tried the passthru command but it didn’t give any result.

I am trying to do the signed and encrypted the message but it is only signing the message, not encrypting.