note 97999 modified in function.ssh2-auth-pubkey-file by danbrown

Setting up public key authentication:

1.  Login to the unix server you want to connect using putty.
2.  mkdir .ssh (there is a dot before ssh)
3.  cd .ssh
4.  ssh-keygen -t rsa mykey
5.  Enter passphrase as test
6.  ls -al -> you will find two files mykey , mykey.pub
7.  cat mykey.pub >>authorized_keys
8.  cat mykey
9.  Copy what you get on screen to notepad and save it as "c:\mykey" (within quotes)
10.  cat mykey.pub
11.  Copy what you get on screen to notepad and save it as "c:\mykey.pub" (within quotes)

<?php

function my_ssh_disconnect($reason, $message, $language) 
{
  printf("Server disconnected with reason code [%d] and message: %s\n", $reason, $message);
}

//Open a connection forcing 3des-cbc when sending packets, any strength aes cipher when receiving packets, no compression in either direction, and Group1 key exchange. 
$methods = array(
  'kex' => 'diffie-hellman-group1-sha1',
  'client_to_server' => array(
   'crypt' => 'aes256-cbc',
   'comp' => 'none',
   'mac' => 'hmac-sha1'),
  'server_to_client' => array(
   'crypt' => 'aes256-cbc',
   'comp' => 'none',
   'mac' => 'hmac-sha1'));

$callbacks = array('disconnect' => 'my_ssh_disconnect');

      // Function to run a command on the unix server

      function run_cmd($ssh_host, $user_name, $keyfilename, $ssh_command)
      {
          $connection = ssh2_connect($ssh_host, 22, $methods, $callbacks);
          if (!$connection) die('Connection failed');
          if (ssh2_auth_pubkey_file($connection, $user_name, $keyfilename.".pub", $keyfilename, 'test'))
          {
            echo "Public Key Authentication Successful as user: $user_name";
          }
          else
          {
            die('Public Key Authentication Failed');
          }

          $stream = ssh2_exec($connection, $ssh_command);
          $i=0;
          stream_set_blocking($stream, true);
          $line = stream_get_line($stream, 1024, "\n");
          while (!feof($stream))                                                                               
          {
                  echo $line.' ';
                  $line = stream_get_line($stream, 1024, "\n");
                  $i++;
          }  
          echo "Count : ".$i;
          flush();
          unset($stream);  
      }

      function my_ssh_disconnect($reason, $message, $language)
      {
            printf("Server disconnected with reason code [%d] and message: %s\n",
            $reason, $message);
      }

      // Main Code

      $user_name = "USERID";
      $keydir = "c:\\";
      $search_string = 'needle';
      $keyfilename= $keydir.'mykey';
      $ssh_host = "foo.bar.com";
      $ssh_command = 'grep "'.$search_string.'" /haystack/*.log';
      run_cmd($ssh_host, $user_name, $keyfilename, $ssh_command);

      $ssh_command = 'ls -al';
      run_cmd($ssh_host, $user_name, $keyfilename, $ssh_command);
?>

--was--
Setting up public key authentication:

1.  Login to the unix server you want to connect using putty.
2.  mkdir .ssh (there is a dot before ssh)
3.  cd .ssh
4.  ssh-keygen -t rsa mykey
5.  Enter passphrase as test
6.  ls -al -> you will find two files mykey , mykey.pub
7.  cat mykey.pub >>authorized_keys
8.  cat mykey
9.  Copy what you get on screen to notepad and save it as "c:\mykey" (within quotes)
10.  cat mykey.pub
11.  Copy what you get on screen to notepad and save it as "c:\mykey.pub" (within quotes)

PHP Code:

function my_ssh_disconnect($reason, $message, $language) 
{
  printf("Server disconnected with reason code [%d] and message: %s\n", $reason, $message);
}

//Open a connection forcing 3des-cbc when sending packets, any strength aes cipher when receiving packets, no compression in either direction, and Group1 key exchange. 
$methods = array(
  'kex' => 'diffie-hellman-group1-sha1',
  'client_to_server' => array(
   'crypt' => 'aes256-cbc',
   'comp' => 'none',
   'mac' => 'hmac-sha1'),
  'server_to_client' => array(
   'crypt' => 'aes256-cbc',
   'comp' => 'none',
   'mac' => 'hmac-sha1'));

$callbacks = array('disconnect' => 'my_ssh_disconnect');

      // Function to run a command on the unix server

      function run_cmd($ssh_host, $user_name, $keyfilename, $ssh_command)
      {
          $connection = ssh2_connect($ssh_host, 22, $methods, $callbacks);
          if (!$connection) die('Connection failed');
          if (ssh2_auth_pubkey_file($connection, $user_name, $keyfilename.".pub", $keyfilename, 'test'))
          {
            echo "Public Key Authentication Successful as user: $user_name";
          }
          else
          {
            die('Public Key Authentication Failed');
          }

          $stream = ssh2_exec($connection, $ssh_command);
          $i=0;
          stream_set_blocking($stream, true);
          $line = stream_get_line($stream, 1024, "\n");
          while (!feof($stream))                                                                               
          {
                  echo $line.' ';
                  $line = stream_get_line($stream, 1024, "\n");
                  $i++;
          }  
          echo "Count : ".$i;
          flush();
          unset($stream);  
      }

      function my_ssh_disconnect($reason, $message, $language)
      {
            printf("Server disconnected with reason code [%d] and message: %s\n",
            $reason, $message);
      }

      // Main Code

      $user_name = "USERID";
      $keydir = "c:\\";
      $search_string = 'needle';
      $keyfilename= $keydir.'mykey';
      $ssh_host = "foo.bar.com";
      $ssh_command = 'grep "'.$search_string.'" /haystack/*.log';
      run_cmd($ssh_host, $user_name, $keyfilename, $ssh_command);

      $ssh_command = 'ls -al';
      run_cmd($ssh_host, $user_name, $keyfilename, $ssh_command);
?>

http://php.net/manual/en/function.ssh2-auth-pubkey-file.php