From cecde162c97ceb3309b29c98ef1648abcb0379bf Mon Sep 17 00:00:00 2001
From: PiBa-NL <pba_2k3@yahoo.com>
Date: Fri, 22 Nov 2013 16:29:16 +0100
Subject: haproxy-devel, change certificate signer check
 haproxy_cert_signed_by(a,b)

---
 config/haproxy-devel/haproxy.xml       |   5 -
 config/haproxy-devel/haproxy_utils.inc |  29 ++-
 config/haproxy-devel/isCertSigner.inc  | 361 ---------------------------------
 3 files changed, 26 insertions(+), 369 deletions(-)
 delete mode 100644 config/haproxy-devel/isCertSigner.inc

(limited to 'config')

diff --git a/config/haproxy-devel/haproxy.xml b/config/haproxy-devel/haproxy.xml
index f7bac704..299d76c6 100644
--- a/config/haproxy-devel/haproxy.xml
+++ b/config/haproxy-devel/haproxy.xml
@@ -99,11 +99,6 @@
 		<chmod>077</chmod>
 		<item>http://www.pfsense.com/packages/config/haproxy-devel/haproxy_xmlrpcsyncclient.inc</item>
 	</additional_files_needed>
-	<additional_files_needed>
-		<prefix>/usr/local/pkg/</prefix>
-		<chmod>077</chmod>
-		<item>http://www.pfsense.com/packages/config/haproxy-devel/isCertSigner.inc</item>
-	</additional_files_needed>
 	<additional_files_needed>
 		<prefix>/usr/local/pkg/</prefix>
 		<chmod>077</chmod>
diff --git a/config/haproxy-devel/haproxy_utils.inc b/config/haproxy-devel/haproxy_utils.inc
index e826f530..940c816f 100644
--- a/config/haproxy-devel/haproxy_utils.inc
+++ b/config/haproxy-devel/haproxy_utils.inc
@@ -31,6 +31,8 @@
   be moved to the general pfSense php library for possible easy use by other parts of pfSense
 */
 
+require_once("config.inc");
+
 function haproxy_interface_ip($interfacebindname,$userfriendly=false){
 	$list = haproxy_get_bindable_interfaces();
 	$item = $list[$interfacebindname];
@@ -153,11 +155,32 @@ function haproxy_get_bindable_interfaces($ipv="ipv4,ipv6", $interfacetype="any,l
 	return $bindable;
 }
 
+function haproxy_get_cert_extensions($crt){
+	$cert = openssl_x509_parse(base64_decode($crt['crt']));
+	return $cert['extensions'];
+}
+
+function haproxy_get_cert_authoritykeyidentifier($cert)
+{
+	$certextension = haproxy_get_cert_extensions($cert);
+	$lines = preg_split('/[\n]+/',$certextension['authorityKeyIdentifier']);
+	return substr($lines[0],6);// cut off the starting string 'keyid:'
+}
+function haproxy_get_cert_subjectKeyIdentifier($cert)
+{
+	$certextension = haproxy_get_cert_extensions($cert);
+	$lines = preg_split('/[\n]+/',$certextension['subjectKeyIdentifier']);
+	return $lines[0];
+}
+
 function haproxy_cert_signed_by($cert, $signedbycert) {
-	// uses function isCertSigner(a,b) from isCertSigner.inc to check if $cert was signed by $signedbycert
-	// returns true if it is
-	return isCertSigner(base64_decode($cert['crt']), base64_decode($signedbycert['crt']));
+	// checks if $cert was signed by $signedbycert
+	// this does NOT validate a proper signature but only checks if the extension properties match.
+	$authoritykeyid = haproxy_get_cert_authoritykeyidentifier($cert);
+	$subjectid = haproxy_get_cert_subjectKeyIdentifier($signedbycert);
+	return $authoritykeyid == $subjectid;
 }
+
 function haproxy_get_certificates(){
 	global $config;
 	$allcerts = array();
diff --git a/config/haproxy-devel/isCertSigner.inc b/config/haproxy-devel/isCertSigner.inc
deleted file mode 100644
index d964129f..00000000
--- a/config/haproxy-devel/isCertSigner.inc
+++ /dev/null
@@ -1,361 +0,0 @@
-<?php
-/**
- * Is one pem encoded certificate the signer of another?
- *
- * The PHP openssl functionality is severely limited by the lack of a stable
- * api and documentation that might as well have been encrypted itself.
- * In particular the documention on openssl_verify() never explains where
- * to get the actual signature to verify.  The isCertSigner() function below
- * will accept two PEM encoded certs as arguments and will return true if
- * one certificate was used to sign the other.  It only relies on the
- * openssl_pkey_get_public() and openssl_public_decrypt() openssl functions,
- * which should stay fairly stable.  The ASN parsing code snippets were mostly
- * borrowed from the horde project's smime.php.
- *
- * @author Mike Green <mikey at badpenguins dot com>
- * @copyright Copyright (c) 2010, Mike Green
- * @license http://opensource.org/licenses/gpl-2.0.php GPLv2
- */
-
-/**
- * If viewSource is in the request string, show the source, luke.
- */
-if (isset($_REQUEST['viewSource'])) {
-    die(highlight_file(__FILE__));
-    }
-
-/**
- * Extract signature from der encoded cert.
- * Expects x509 der encoded certificate consisting of a section container
- * containing 2 sections and a bitstream.  The bitstream contains the
- * original encrypted signature, encrypted by the public key of the issuing
- * signer.
- * @param string $der
- * @return string on success
- * @return bool false on failures
- */
-function extractSignature($der=false) {
-    if (strlen($der) < 5) { return false; }
-    // skip container sequence
-    $der = substr($der,4);
-    // now burn through two sequences and the return the final bitstream
-    while(strlen($der) > 1) {
-        $class = ord($der[0]);
-        $classHex = dechex($class);
-        switch($class) {
-            // BITSTREAM
-            case 0x03:
-                $len = ord($der[1]);
-                $bytes = 0;
-                if ($len & 0x80) {
-                    $bytes = $len & 0x0f;
-                    $len = 0;
-                    for ($i = 0; $i < $bytes; $i++) {
-                        $len = ($len << 8) | ord($der[$i + 2]);
-                        }
-                    }
-                return substr($der,3 + $bytes, $len);
-            break;
-            // SEQUENCE
-            case 0x30:
-                $len = ord($der[1]);
-                $bytes = 0;
-                if ($len & 0x80) {
-                    $bytes = $len & 0x0f;
-                    $len = 0;
-                    for($i = 0; $i < $bytes; $i++) {
-                        $len = ($len << 8) | ord($der[$i + 2]);
-                        }
-                    }
-                $contents = substr($der, 2 + $bytes, $len);
-                $der = substr($der,2 + $bytes + $len);
-            break;
-            default:
-                return false;
-            break;
-            }
-        }
-    return false;
-    }
-
-/**
- * Get signature algorithm oid from der encoded signature data.
- * Expects decrypted signature data from a certificate in der format.
- * This ASN1 data should contain the following structure:
- * SEQUENCE
- *    SEQUENCE
- *       OID    (signature algorithm)
- *       NULL
- * OCTET STRING (signature hash)
- * @return bool false on failures
- * @return string oid
- */
-function getSignatureAlgorithmOid($der=null) {
-    // Validate this is the der we need...
-    if (!is_string($der) or strlen($der) < 5) { return false; }
-    $bit_seq1 = 0;
-    $bit_seq2 = 2;
-    $bit_oid  = 4;
-    if (ord($der[$bit_seq1]) !== 0x30) {
-        die('Invalid DER passed to getSignatureAlgorithmOid()');
-        }
-    if (ord($der[$bit_seq2]) !== 0x30) {
-        die('Invalid DER passed to getSignatureAlgorithmOid()');
-        }
-    if (ord($der[$bit_oid]) !== 0x06) {
-        die('Invalid DER passed to getSignatureAlgorithmOid');
-        }
-    // strip out what we don't need and get the oid
-    $der = substr($der,$bit_oid);
-    // Get the oid
-    $len = ord($der[1]);
-    $bytes = 0;
-    if ($len & 0x80) {
-        $bytes = $len & 0x0f;
-        $len = 0;
-        for ($i = 0; $i < $bytes; $i++) {
-            $len = ($len << 8) | ord($der[$i + 2]);
-            }
-        }
-    $oid_data = substr($der, 2 + $bytes, $len);
-    // Unpack the OID
-    $oid  = floor(ord($oid_data[0]) / 40);
-    $oid .= '.' . ord($oid_data[0]) % 40;
-    $value = 0;
-    $i = 1;
-    while ($i < strlen($oid_data)) {
-        $value = $value << 7;
-        $value = $value | (ord($oid_data[$i]) & 0x7f);
-        if (!(ord($oid_data[$i]) & 0x80)) {
-            $oid .= '.' . $value;
-            $value = 0;
-            }
-        $i++;
-        }
-    return $oid;
-    }
-
-/**
- * Get signature hash from der encoded signature data.
- * Expects decrypted signature data from a certificate in der format.
- * This ASN1 data should contain the following structure:
- * SEQUENCE
- *    SEQUENCE
- *       OID    (signature algorithm)
- *       NULL
- * OCTET STRING (signature hash)
- * @return bool false on failures
- * @return string hash
- */
-function getSignatureHash($der=null) {
-    // Validate this is the der we need...
-    if (!is_string($der) or strlen($der) < 5) { return false; }
-    if (ord($der[0]) !== 0x30) {
-        die('Invalid DER passed to getSignatureHash()');
-        }
-    // strip out the container sequence
-    $der = substr($der,2);
-    if (ord($der[0]) !== 0x30) {
-        die('Invalid DER passed to getSignatureHash()');
-        }
-    // Get the length of the first sequence so we can strip it out.
-    $len = ord($der[1]);
-    $bytes = 0;
-    if ($len & 0x80) {
-        $bytes = $len & 0x0f;
-        $len = 0;
-        for ($i = 0; $i < $bytes; $i++) {
-            $len = ($len << 8) | ord($der[$i + 2]);
-            }
-        }
-    $der = substr($der, 2 + $bytes + $len);
-    // Now we should have an octet string
-    if (ord($der[0]) !== 0x04) {
-        die('Invalid DER passed to getSignatureHash()');
-        }
-    $len = ord($der[1]);
-    $bytes = 0;
-    if ($len & 0x80) {
-        $bytes = $len & 0x0f;
-        $len = 0;
-        for ($i = 0; $i < $bytes; $i++) {
-            $len = ($len << 8) | ord($der[$i + 2]);
-            }
-        }
-    return bin2hex(substr($der, 2 + $bytes, $len));
-    }
-
-/**
- * Determine if one cert was used to sign another
- * Note that more than one CA cert can give a positive result, some certs
- * re-issue signing certs after having only changed the expiration dates.
- * @param string $cert - PEM encoded cert
- * @param string $caCert - PEM encoded cert that possibly signed $cert
- * @return bool
- */
-function isCertSigner($certPem=null,$caCertPem=null) {
-    if (!function_exists('openssl_pkey_get_public')) {
-        die('Need the openssl_pkey_get_public() function.');
-        }
-    if (!function_exists('openssl_public_decrypt')) {
-        die('Need the openssl_public_decrypt() function.');
-        }
-    if (!function_exists('hash')) {
-        die('Need the php hash() function.');
-        }
-    if (empty($certPem) or empty($caCertPem)) { return false; }
-    // Convert the cert to der for feeding to extractSignature.
-    $certDer = pemToDer($certPem);
-    if (!is_string($certDer)) { die('invalid certPem'); }
-    // Grab the encrypted signature from the der encoded cert.
-    $encryptedSig = extractSignature($certDer);
-    if (!is_string($encryptedSig)) {
-        die('Failed to extract encrypted signature from certPem.');
-        }
-    // Extract the public key from the ca cert, which is what has
-    // been used to encrypt the signature in the cert.
-    $pubKey = openssl_pkey_get_public($caCertPem);
-    if ($pubKey === false) {
-        die('Failed to extract the public key from the ca cert.');
-        }
-    // Attempt to decrypt the encrypted signature using the CA's public
-    // key, returning the decrypted signature in $decryptedSig.  If
-    // it can't be decrypted, this ca was not used to sign it for sure...
-    $rc = openssl_public_decrypt($encryptedSig,$decryptedSig,$pubKey);
-    if ($rc === false) { return false; }
-    // We now have the decrypted signature, which is der encoded
-    // asn1 data containing the signature algorithm and signature hash.
-    // Now we need what was originally hashed by the issuer, which is
-    // the original DER encoded certificate without the issuer and
-    // signature information.
-    $origCert = stripSignerAsn($certDer);
-    if ($origCert === false) {
-        die('Failed to extract unsigned cert.');
-        }
-    // Get the oid of the signature hash algorithm, which is required
-    // to generate our own hash of the original cert.  This hash is
-    // what will be compared to the issuers hash.
-    $oid = getSignatureAlgorithmOid($decryptedSig);
-    if ($oid === false) {
-        die('Failed to determine the signature algorithm.');
-        }
-    switch($oid) {
-        case '1.2.840.113549.2.2':     $algo = 'md2';    break;
-        case '1.2.840.113549.2.4':     $algo = 'md4';    break;
-        case '1.2.840.113549.2.5':     $algo = 'md5';    break;
-        case '1.3.14.3.2.18':          $algo = 'sha';    break;
-        case '1.3.14.3.2.26':          $algo = 'sha1';   break;
-        case '2.16.840.1.101.3.4.2.1': $algo = 'sha256'; break;
-        case '2.16.840.1.101.3.4.2.2': $algo = 'sha384'; break;
-        case '2.16.840.1.101.3.4.2.3': $algo = 'sha512'; break;
-        default:
-            die('Unknown signature hash algorithm oid: ' . $oid);
-        break;
-        }
-    // Get the issuer generated hash from the decrypted signature.
-    $decryptedHash = getSignatureHash($decryptedSig);
-    // Ok, hash the original unsigned cert with the same algorithm
-    // and if it matches $decryptedHash we have a winner.
-    $certHash = hash($algo,$origCert);
-    return ($decryptedHash === $certHash);
-    }
-
-/**
- * Convert pem encoded certificate to DER encoding
- * @return string $derEncoded on success
- * @return bool false on failures
- */
-function pemToDer($pem=null) {
-    if (!is_string($pem)) { return false; }
-    $cert_split = preg_split('/(-----((BEGIN)|(END)) CERTIFICATE-----)/',$pem);
-    if (!isset($cert_split[1])) { return false; }
-    return base64_decode($cert_split[1]);
-    }
-
-/**
- * Obtain der cert with issuer and signature sections stripped.
- * @param string $der - der encoded certificate
- * @return string $der on success
- * @return bool false on failures.
- */
-function stripSignerAsn($der=null) {
-    if (!is_string($der) or strlen($der) < 8) { return false; }
-    $bit = 4;
-    $len   = ord($der[($bit + 1)]);
-    $bytes = 0;
-    if ($len & 0x80) {
-        $bytes = $len & 0x0f;
-        $len   = 0;
-        for($i = 0; $i < $bytes; $i++) {
-            $len = ($len << 8) | ord($der[$bit + $i + 2]);
-            }
-        }
-    return substr($der,4,$len + 4);
-    }
-/*
-/ **
- * HTML form starts here...
- * /
-
-$answer = 'Enter PEM Encoded Certificates for the Issuer and Subject '
-        . 'and click Submit.  Include the entire certificates, including '
-        . 'the BEGIN CERTIFICATE and END CERTIFICATE lines.';
-
-if (isset($_POST['subjectPem']) and isset($_POST['issuerPem'])) {
-    if (strlen($_POST['subjectPem']) > 0 and strlen($_POST['issuerPem']) > 0) {
-        $rc = isCertSigner($_POST['subjectPem'],$_POST['issuerPem']);
-        if ($rc === true) {
-            $answer = 'The issuer cert DID sign the subject cert.';
-            } else {
-            $answer = 'The issuer cert DID NOT sign the subject cert.';
-            }
-        }
-    }
-?>
-<HTML>
-<BODY BGCOLOR="white">
-<HEAD>
-<TITLE>Is This The Cert Signer?</TITLE>
-<STYLE TYPE="text/css">
-textarea {
-    font-size: 11px;
-    }
-</STYLE>
-</HEAD>
-<BODY>
-<DIV ALIGN="center">
-<FORM NAME="check_certs" METHOD="post" action="<?= $_SERVER['PHP_SELF']; ?>">
-<TABLE BORDER="1" WIDTH="500px">
-    <TR>
-        <TD><?= $answer; ?></TD>
-    </TR>
-    <TR>
-        <TH>Issuer Certificate (<A HREF="#" ONCLICK="javascript:document.check_certs.issuerPem.value='';">clear</A>)</TH>
-    </TR>
-    <TR>
-        <TD>
-            <TEXTAREA NAME="issuerPem" ROWS="20" COLS="70"><?= (isset($_POST['issuerPem'])) ? $_POST['issuerPem'] : ''; ?></TEXTAREA>
-        </TD>
-    </TR>
-    <TR>
-        <TH>Subject Certificate (<A HREF="#" ONCLICK="javascript:document.check_certs.subjectPem.value='';">clear</A>)</TH>
-    </TR>
-    <TR>
-        <TD>
-            <TEXTAREA NAME="subjectPem" ROWS="20" COLS="70"><?= (isset($_POST['subjectPem'])) ? $_POST['subjectPem'] : ''; ?></TEXTAREA>
-        </TD>
-    </TR>
-    <TR>
-        <TD ALIGN="right">
-            (<A HREF="<?= $_SERVER['PHP_SELF']; ?>?viewSource">view source</A>)
-            <INPUT TYPE="submit" NAME="submit" VALUE="submit">
-        </TD>
-    </TR>
-</TABLE>
-</FORM>
-</DIV>
-</BODY>
-</HTML>
-
-*/
-?>
\ No newline at end of file
-- 
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