helper functions for Diaspora cert mangling

1 files changed, 52 insertions, 0 deletions

diff --git a/include/certfns.php b/include/certfns.php
new file mode 100644
index 000000000..70d2b54a0
--- /dev/null
+++ b/include/certfns.php
@@ -0,0 +1,52 @@
+<?php
+
+require_once('library/ASNValue.class.php');
+
+function DerToPem($Der, $Private=false)
+{
+    //Encode:
+    $Der = base64_encode($Der);
+    //Split lines:
+    $lines = str_split($Der, 65);
+    $body = implode("\n", $lines);
+    //Get title:
+    $title = $Private? 'RSA PRIVATE KEY' : 'PUBLIC KEY';
+    //Add wrapping:
+    $result = "-----BEGIN {$title}-----\n";
+    $result .= $body . "\n";
+    $result .= "-----END {$title}-----\n";
+ 
+    return $result;
+}
+
+function pkcs8_encode($Modulus,$PublicExponent) {
+	//Encode key sequence
+	$modulus = new ASNValue(ASNValue::TAG_INTEGER);
+	$modulus->SetIntBuffer($Modulus);
+	$publicExponent = new ASNValue(ASNValue::TAG_INTEGER);
+	$publicExponent->SetInt($PublicExponent);
+	$keySequenceItems = array($modulus, $publicExponent);
+	$keySequence = new ASNValue(ASNValue::TAG_SEQUENCE);
+	$keySequence->SetSequence($keySequenceItems);
+	//Encode bit string
+	$bitStringValue = $keySequence->Encode();
+	$bitStringValue = chr(0x00) . $bitStringValue; //Add unused bits byte
+	$bitString = new ASNValue(ASNValue::TAG_BITSTRING);
+	$bitString->Value = $bitStringValue;
+	//Encode body
+	$bodyValue = "\x30\x0d\x06\x09\x2a\x86\x48\x86\xf7\x0d\x01\x01\x01\x05\x00" . $bitString->Encode();
+	$body = new ASNValue(ASNValue::TAG_SEQUENCE);
+	$body->Value = $bodyValue;
+	//Get DER encoded public key:
+	$PublicDER = $body->Encode();
+	return $PublicDER;
+}
+
+
+function metopem($m,$e) {
+	$der = pkcs8_emcode($m,$e);
+	$key = DerToPem($der,true);
+	return $key;
+}	
+
+