Wordpress s3 Protected Link

miralize

Hey guys,

I'm have quite a bothersome problem. My client wants to store files, (often very large) on their s3 bucket. The site is to sell the items and I decided to use wordpress. I'm using the shopp plugin, and I got most of it working. The thing I'm having a problem with is the encrypted link to download.

When a customer pays for an item, they are redirected to the reciept page, where they would usually get a link to the download, if it was on the server. But its not.

I've found a plugin which works perfectly in wordpress, here, which can grab your access key, secret key and uses a shortcode for the file link. Problem is i have to use a field that is in the shopp plugin, called spec for each file, and that doesnt support the shortcode. How do I strip the shortcode and backend information so that all it needs is the name of a file on the s3 hosting.

php is here
[PHP]<?php
/*
Plugin Name: Amazon S3 URL Generator
Plugin URI: http://codepolice.net/2008/12/08/generate-expiring-urls-for-amazon-s3-via-a-wordpress-plugin/
Description: Allows you to add a Querystring protected URL to a object in a Amazon S3 bucket.
Version: 0.5
Date: 2008-01-20
Author: ola@27kilobyte.se
Author URI: http://codepolice.net
Contributors: Made by stuckish@27kilobyte.se, Based on script by George Pearce (http://www.fused.org.uk/2008/08/s3-query-string-authentication-generator/comment-page-1/#comment-5501)
*/

function s3Url($text) {
$AWS_S3_KEY = get_option('aws_s3_key');
$AWS_S3_SECRET = get_option('aws_s3_secret');;
$tag_pattern = '/(\[S3 bucket\=(.*?)\ text\=(.*?)\](.*?)\[\/S3\])/i';

// if you want to remove the password (ish) protection, remove the above and the } else { exit; } from the bottom of the script.
define("AWS_S3_KEY", $AWS_S3_KEY); // replace this with your AWS S3 key
define("AWS_S3_SECRET", $AWS_S3_SECRET); // replace this with your secret key.
$expires = time()+get_option('expire_seconds');

if (preg_match_all ($tag_pattern, $text, $matches)) {

for ($m=0; $m<count($matches[0]); $m++) {
$bucket = $matches[2][$m];
$link_text = $matches[3][$m];
$resource = $matches[4][$m];

$string_to_sign = "GET\n\n\n{$expires}\n/{$bucket}/{$resource}";
$signature = urlencode(base64_encode((hash_hmac("sha1", utf8_encode($string_to_sign), AWS_S3_SECRET, TRUE))));

$authentication_params = "AWSAccessKeyId=".AWS_S3_KEY;
$authentication_params.= "&Expires={$expires}";
$authentication_params.= "&Signature={$signature}";

$tag_pattern_match = "/(\[S3 bucket\=(.*?)\ text\={$link_text}\]{$resource}\[\/S3\])/i";

if(strlen($link_text) == 0)
{
$link = "http://{$bucket}/{$resource}?{$authentication_params}";
}
else
{
$link = "<a href='http://{$bucket}/{$resource}?{$authentication_params}'>{$link_text}</a>";
}

$text = preg_replace($tag_pattern_match,$link,$text);
}
}

return $text;
}

function s3_url_generator_menu() {
add_options_page('S3 URL Generator Options', 'S3 URL Generator', 8, __FILE__, 's3_url_generator_options');
}

function s3_url_generator_options() {
?>
<div class="wrap">
<h2>Amazon S3 URL Generator</h2>
<form method="post" action="options.php">
<?php wp_nonce_field('update-options'); ?>
<table class="form-table">
<tr valign="top">
<th scope="row">Amazon S3 Key</th>
<td><input type="text" name="aws_s3_key" style="width: 400px;" value="<?php echo get_option('aws_s3_key'); ?>" /></td>
</tr>
<tr valign="top">
<th scope="row">Amazon S3 Secret</th>
<td><input type="text" name="aws_s3_secret" style="width: 400px;" value="<?php echo get_option('aws_s3_secret'); ?>" /></td>
</tr>
<tr valign="top">
<th scope="row">Expire (In seconds)</th>
<td><input type="text" name="expire_seconds" style="width: 400px;" value="<?php echo get_option('expire_seconds'); ?>" /></td>
</tr>
</table>
<input type="hidden" name="action" value="update" />
<input type="hidden" name="page_options" value="aws_s3_key,aws_s3_secret,expire_seconds" />

<p class="submit">
<input type="submit" name="Submit" value="<?php _e('Save Changes') ?>" />
</p>

<h3>Usage</h3>
<p>
[S3 bucket=yourbucket text=your link text]the_object_name.txt[/S3]
</p>
<p>
Read more at my blog - <a target="_blank" href="http://www.codepolice.net/2008/12/08/generate-expiring-urls-for-amazon-s3-via-a-wordpress-plugin/"&gt; codepolice.net/2008/12/08/generate-expiring-urls-for-amazon-s3-via-a-wordpress-plugin/</a>
</p>
<p>
This is just a "exprimental" version. If you have suggestions on how to improve this plugin pleace comment in the blog.
</p>

</form>
</div>
<?php
}
add_action('admin_menu', 's3_url_generator_menu');
add_filter('the_content', 's3Url');
?>[/PHP]

Thanks.

Sean