basic diaspora encryption

This commit is contained in:
Friendika 2011-08-08 21:44:29 -07:00
parent 6be5da67b1
commit df3062c612

90
include/diaspora.php Normal file
View file

@ -0,0 +1,90 @@
<?php
function diaspora_base_message($type,$data) {
$tpl = get_markup_template('diaspora_' . $type . '.tpl');
if(! $tpl)
return '';
return replace_macros($tpl,$data);
}
function diaspora_msg_build($msg,$user,$contact,$prvkey,$pubkey) {
$a = get_app();
$inner_aes_key = random_string(16);
$b_inner_aes_key = base64_encode($inner_aes_key);
$inner_iv = random_string(16);
$b_inner_iv = base64_encode($inner_iv);
$outer_aes_key = random_string(16);
$b_outer_aes_key = base64_encode($outer_aes_key);
$outer_iv = random_string(16);
$b_outer_iv = base64_encode($outer_iv);
$handle = 'acct:' . $user['nickname'] . '@' . substr($a->get_baseurl(), strpos('://') + 3);
$padded_data = pkcs5_pad($msg);
$inner_encrypted = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $inner_aes_key, $padded_data, MCRYPT_MODE_CBC, $inner_iv);
$b64_data = base64_encode($inner_encrypted);
$b64url_data = base64url_encode($b64_data);
$b64url_stripped = str_replace(array("\n","\r"," ","\t"),array('','','',''),$b64url_data);
$lines = str_split($b64url_stripped,60);
$data = implode("\n",$lines);
$data = $data . (($data[-1] != "\n") ? "\n" : '') ;
$type = 'application/atom+xml';
$encoding = 'base64url';
$alg = 'RSA-SHA256';
$signable_data = $data . '.' . base64url_encode($type) . "\n" . '.'
. base64url_encode($encoding) . "\n" . '.' . base64url_encode($alg) . "\n";
$signature = '';
$result = openssl_sign($signable_data,$signature,$prvkey,'SHA256');
$sig = base64url_encode($signature);
$decrypted_header = <<< EOT
<decrypted_header>
<iv>$b_inner_iv</iv>
<aes_key>$b_inner_aes_key</aes_key>
<author>
<name>{$contact['name']}</name>
<uri>$handle</uri>
</author>
</decrypted_header>
EOT;
$decrypted_header = pkcs5_pad($decrypted_header);
$ciphertext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $outer_aes_key, $decrypted_header, MCRYPT_MODE_CBC, $outer_iv);
$outer_json = json_encode(array('iv' => $b64_outer_iv,'key' => $b64_outer_aes_key));
$encrypted_outer_key_bundle = '';
openssl_public_encrypt($outer_json,$encrypted_outer_key_bundle,$pubkey);
$b64_encrypted_outer_key_bundle = base64_encode($encrypted_outer_key_bundle);
$encrypted_header_json_object = json_encode(array('aes_key' => base64_encode($encrypted_outer_key_bundle),
'ciphertext' => base64_encode($ciphertext)));
$encrypted_header = '<encrypted_header>' . base64_encode($encrypted_header_json_object) . '</encrypted_header>';
$magicenv = <<< EOT
<?xml version='1.0' encoding='UTF-8'?>
<entry xmlns='http://www.w3.org/2005/Atom'>
$encrypted_header
<me:env xmlns:me="http://salmon-protocol.org/ns/magic-env">
<me:encoding>base64url</me:encoding>
<me:alg>RSA-SHA256</me:alg>
<me:data type="application/atom+xml">$data</me:data>
<me:sig>$sig</me:sig>
</me:env>
</entry>
EOT;
return $magic_env;
}