PHP code for creating payment requests

php/README.txt

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+Useful PHP5 code for generating/handling Payment messages.
+
+Relies on Protobuf-PHP for reading/writing protocol buffer encoded files:
+  http://drslump.github.com/Protobuf-PHP/
+See that website for installation instructions.
+
+paymentrequest.php was generated from the paymentrequest.proto file by running the
+protoc-gen-php tool in the directory above this one, like this:
+
+  protoc-gen-php -o php -i $(pwd) paymentrequest.proto
+

php/certificates.php

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+<?php
+/*
+ * Some routines for dealing with certificates
+ * All assume you have support for openssl compiled into
+ * php.
+ */
+
+/*
+ * Return true if $certificate is a root cert.
+ * $certificate must be a parsed array, not raw unparsed data.
+ */
+function is_root_certificate($certificate)
+{
+    return $certificate['issuer'] == $certificate['subject'];
+}
+
+/*
+ * Given a parsed leaf certificate, fetch its parent
+ * and return its (unparsed) data.
+ */
+function fetch_certificate_parent($leafCertificate)
+{
+    $pattern = '/CA Issuers - URI:(\\S*)/';
+    $matches = array();
+    $nMatches = preg_match_all($pattern, $leafCertificate['extensions']['authorityInfoAccess'], $matches);
+    if ($nMatches == 0) return false;
+    foreach ($matches[1] as $url) {
+        $parentCert = file_get_contents($url);
+        if ($parentCert && parse_certificate($parentCert)) return $parentCert;
+    }
+    return false;
+}
+
+/*
+ * Either parse a PEM certificate, or convert DER to PEM and then
+ * parse.
+ */
+function parse_certificate($certData)
+{
+    $begin = "-----BEGIN CERTIFICATE-----";
+    $end = "-----END CERTIFICATE-----";
+
+    if (strpos($certData, $begin) !== false) {
+        return openssl_x509_parse($certData);
+    }
+    $d = $begin."\n";
+    $d .= chunk_split(base64_encode($certData));
+    $d .= $end."\n";
+    return openssl_x509_parse($d);
+}
+
+function pem2der($pem_data) {
+   $begin = "CERTIFICATE-----";
+   $end   = "-----END";
+   if (strpos($pem_data, $begin) === false) return $pem_data;
+   $pem_data = substr($pem_data, strpos($pem_data, $begin)+strlen($begin));    
+   $pem_data = substr($pem_data, 0, strpos($pem_data, $end));
+   $der = base64_decode($pem_data);
+   return $der;
+}
+
+/*
+ * Fetch a whole certificate chain, starting with
+ * a leaf certificate. Returns raw certificate data
+ * in an array, leaf certificate first.
+ */
+function fetch_chain($leaf)
+{
+    $result = array();
+
+    $cert = parse_certificate($leaf);
+    if ($cert === false) return false;
+    $certData = pem2der($leaf);
+
+    while ($cert !== false && !is_root_certificate($cert))
+    {
+        $result[] = $certData;
+        $certData = fetch_certificate_parent($cert);
+        $cert = parse_certificate($certData);
+    }
+
+    return $result;
+}
+
+?>