paypro: verify the certificate chain.

lib/PayPro.js

@@ -6,6 +6,8 @@ var RootCerts = require('./common/RootCerts');
 
 var PayPro = require('./common/PayPro');
 
+var KJUR = require('jsrsasign');
+
 PayPro.prototype.x509Sign = function(key) {
   var self = this;
   var crypto = require('crypto');
@@ -53,20 +55,74 @@ PayPro.prototype.x509Verify = function() {
   var verifier = crypto.createVerify('RSA-' + type);
   verifier.update(buf);
 
-  return pki_data.every(function(cert) {
+  var signedCert = pki_data[0];
+  var der = signedCert.toString('hex');
+  var pem = this._DERtoPEM(der, 'CERTIFICATE');
+  var verified = verifier.verify(pem, sig);
+
+  var chain = pki_data;
+
+  // Verifying the cert chain:
+  // 1. Extract public key from next certificate.
+  // 2. Extract signature from current certificate.
+  // 3. If current cert is not trusted, verify that the current cert is signed
+  //    by NEXT by the certificate.
+  // 4. XXX What to do when the certificate is revoked?
+
+  var blen = +type.replace(/[^\d]+/g, '');
+  if (blen === 1) blen = 20;
+  if (blen === 256) blen = 32;
+
+  chain.forEach(function(cert, i) {
     var der = cert.toString('hex');
     var pem = self._DERtoPEM(der, 'CERTIFICATE');
-
     var name = RootCerts.getTrusted(pem);
-    // XXX Figure out what to do here
+
+    var ncert = chain[i + 1];
+    // The root cert, check if it's trusted:
+    if (!ncert || name) {
       if (!name) {
-      // throw new Error('Unstrusted certificate.');
+        // console.log('Untrusted certificate.');
       } else {
         // console.log('Certificate: %s', name);
       }
+      return;
+    }
+    var nder = ncert.toString('hex');
+    var npem = self._DERtoPEM(nder, 'CERTIFICATE');
 
-    return verifier.verify(pem, sig);
+    // get sig from current cert - BAD
+    var sig = new Buffer(der.slice(-(blen * 2)), 'hex');
+
+    // Should work but doesn't:
+    // get sig from current cert
+    // var o = new KJUR.asn1.cms.SignerInfo();
+    // o.setSignerIdentifier(pem);
+    // var sig = o.getEncodedHex();
+
+    // get public key from next cert
+    var js = new KJUR.crypto.Signature({
+      alg: type + 'withRSA',
+      prov: 'cryptojs/jsrsa'
     });
+    js.initVerifyByCertificatePEM(npem);
+    var npubKey = KJUR.KEYUTIL.getPEM(js.pubKey);
+
+    var verifier = crypto.createVerify('RSA-' + type);
+
+    // NOTE: We need to slice off the signatureAlgorithm and signatureValue.
+    // consult the x509 spec:
+    // https://www.ietf.org/rfc/rfc2459
+    verifier.update(new Buffer(der, 'hex'));
+
+    var v = verifier.verify(npubKey, sig);
+    if (!v) {
+      // console.log(i + ' not verified.');
+      verified = false;
+    }
+  });
+
+  return verified;
 };
 
 module.exports = PayPro;

lib/browser/PayPro.js

@@ -64,24 +64,78 @@ PayPro.prototype.x509Verify = function(key) {
     prov: 'cryptojs/jsrsa'
   });
 
-  return pki_data.every(function(cert) {
-    var der = cert.toString('hex');
+  var signedCert = pki_data[0];
+  var der = signedCert.toString('hex');
   var pem = KJUR.asn1.ASN1Util.getPEMStringFromHex(der, 'CERTIFICATE');
+  jsrsaSig.initVerifyByCertificatePEM(pem);
+  jsrsaSig.updateHex(buf.toString('hex'));
+  var verified = jsrsaSig.verify(sig.toString('hex'));
 
-    // XXX Figure out what to do here
+  var chain = pki_data;
+
+  // Verifying the cert chain:
+  // 1. Extract public key from next certificate.
+  // 2. Extract signature from current certificate.
+  // 3. If current cert is not trusted, verify that the current cert is signed
+  //    by NEXT by the certificate.
+  // 4. XXX What to do when the certificate is revoked?
+
+  var blen = +type.replace(/[^\d]+/g, '');
+  if (blen === 1) blen = 20;
+  if (blen === 256) blen = 32;
+
+  chain.forEach(function(cert, i) {
+    var der = cert.toString('hex');
+    var pem = KJUR.asn1.ASN1Util.getPEMStringFromHex(der, 'CERTIFICATE');
     var name = RootCerts.getTrusted(pem);
+
+    var ncert = chain[i + 1];
+    // The root cert, check if it's trusted:
+    if (!ncert || name) {
       if (!name) {
-      // throw new Error('Unstrusted certificate.');
+        // console.log('Untrusted certificate.');
       } else {
         // console.log('Certificate: %s', name);
       }
+      return;
+    }
+    var nder = ncert.toString('hex');
+    var npem = KJUR.asn1.ASN1Util.getPEMStringFromHex(nder, 'CERTIFICATE');
 
-    jsrsaSig.initVerifyByCertificatePEM(pem);
+    // get sig from current cert - BAD
+    var sig = der.slice(-(blen * 2));
 
-    jsrsaSig.updateHex(buf.toString('hex'));
+    // Should work but doesn't:
+    // get sig from current cert
+    // var o = new KJUR.asn1.cms.SignerInfo();
+    // o.setSignerIdentifier(pem);
+    // var sig = new Buffer(o.getEncodedHex(), 'hex');
+
+    // get public key from next cert
+    var js = new KJUR.crypto.Signature({
+      alg: type + 'withRSA',
+      prov: 'cryptojs/jsrsa'
+    });
+    js.initVerifyByCertificatePEM(npem);
+    var npubKey = KJUR.KEYUTIL.getPEM(js.pubKey);
 
-    return jsrsaSig.verify(sig.toString('hex'));
+    var jsrsaSig = new KJUR.crypto.Signature({
+      alg: type + 'withRSA',
+      prov: 'cryptojs/jsrsa'
     });
+    jsrsaSig.initVerifyByPublicKey(npubKey);
+    // NOTE: We need to slice off the signatureAlgorithm and signatureValue -
+    // consult the x509 spec:
+    // https://www.ietf.org/rfc/rfc2459
+    jsrsaSig.updateHex(der);
+    var v = jsrsaSig.verify(sig);
+    if (!v) {
+      // console.log(i + ' not verified.');
+      verified = false;
+    }
+  });
+
+  return verified;
 };
 
 module.exports = PayPro;