Make the pkcs1 format more accepting of cruft

We should be able to deal with any random cruft outside of the BEGIN and
END boundaries.

Author: garethsime

src/formats/pkcs1.js

@@ -2,6 +2,30 @@ var ber = require('asn1').Ber;
 var _ = require('../utils')._;
 var utils = require('../utils');
 
+const PRIVATE_OPENING_BOUNDARY = '-----BEGIN RSA PRIVATE KEY-----';
+const PRIVATE_CLOSING_BOUNDARY = '-----END RSA PRIVATE KEY-----';
+
+const PUBLIC_OPENING_BOUNDARY = '-----BEGIN RSA PUBLIC KEY-----';
+const PUBLIC_CLOSING_BOUNDARY = '-----END RSA PUBLIC KEY-----';
+
+/**
+ * Strips everything around the opening and closing lines, including the lines
+ * themselves.
+ */
+function trimSurroundingText(data, opening, closing) {
+    let openingBoundaryIndex = data.indexOf(opening);
+    if (openingBoundaryIndex < 0) {
+        throw Error('Unsupported key format - Missing BEGIN line');
+    }
+
+    let closingBoundaryIndex = data.indexOf(closing, openingBoundaryIndex);
+    if (closingBoundaryIndex < 0) {
+        throw Error('Unsupported key format - Missing END line');
+    }
+
+    return data.substring(openingBoundaryIndex + opening.length, closingBoundaryIndex);
+}
+
 module.exports = {
     privateExport: function (key, options) {
         options = options || {};
@@ -46,8 +70,7 @@ module.exports = {
             }
 
             if (_.isString(data)) {
-                var pem = data.replace('-----BEGIN RSA PRIVATE KEY-----', '')
-                    .replace('-----END RSA PRIVATE KEY-----', '')
+                let pem = trimSurroundingText(data, PRIVATE_OPENING_BOUNDARY, PRIVATE_CLOSING_BOUNDARY)
                     .replace(/\s+|\n\r|\n|\r$/gm, '');
                 buffer = Buffer.from(pem, 'base64');
             } else {
@@ -103,8 +126,7 @@ module.exports = {
             }
 
             if (_.isString(data)) {
-                var pem = data.replace('-----BEGIN RSA PUBLIC KEY-----', '')
-                    .replace('-----END RSA PUBLIC KEY-----', '')
+                var pem = trimSurroundingText(data, PUBLIC_OPENING_BOUNDARY, PUBLIC_CLOSING_BOUNDARY)
                     .replace(/\s+|\n\r|\n|\r$/gm, '');
                 buffer = Buffer.from(pem, 'base64');
             }
@@ -128,12 +150,13 @@ module.exports = {
      * @param data
      */
     autoImport: function (key, data) {
-        if (/^\s*-----BEGIN RSA PRIVATE KEY-----\s*(?=(([A-Za-z0-9+/=]+\s*)+))\1-----END RSA PRIVATE KEY-----\s*$/g.test(data)) {
+        // [\S\s]* matches zero or more of any character
+        if (/^[\S\s]*-----BEGIN RSA PRIVATE KEY-----\s*(?=(([A-Za-z0-9+/=]+\s*)+))\1-----END RSA PRIVATE KEY-----[\S\s]*$/g.test(data)) {
             module.exports.privateImport(key, data);
             return true;
         }
 
-        if (/^\s*-----BEGIN RSA PUBLIC KEY-----\s*(?=(([A-Za-z0-9+/=]+\s*)+))\1-----END RSA PUBLIC KEY-----\s*$/g.test(data)) {
+        if (/^[\S\s]*-----BEGIN RSA PUBLIC KEY-----\s*(?=(([A-Za-z0-9+/=]+\s*)+))\1-----END RSA PUBLIC KEY-----[\S\s]*$/g.test(data)) {
             module.exports.publicImport(key, data);
             return true;
         }

test/tests.js

@@ -336,6 +336,21 @@ describe('NodeRSA', function () {
                         assert.equal(key.exportKey(), fileKeyPKCS1);
                     });
 
+                    it('should gracefully handle data outside of encapsulation boundaries for private keys', function () {
+                        let privateFileWithNoise = 'Lorem ipsum' + fs.readFileSync(keysFolder + 'private_pkcs1.pem') + 'dulce et decorum';
+                        let key = new NodeRSA(privateFileWithNoise);
+                        assert.equal(key.exportKey(), fileKeyPKCS1);
+                    });
+
+                    it('should gracefully handle data outside of encapsulation boundaries for public keys', function () {
+                        let publicFileWithNoise = 'Lorem ipsum' + fs.readFileSync(keysFolder + 'public_pkcs1.pem') + 'dulce et decorum';
+                        let publicNodeRSA = new NodeRSA(publicFileWithNoise);
+                        assert.instanceOf(privateNodeRSA.keyPair, Object);
+                        assert(publicNodeRSA.isPublic());
+                        assert(publicNodeRSA.isPublic(true));
+                        assert(!publicNodeRSA.isPrivate());
+                    });
+
                     it('.importKey() from private components', function () {
                         var key = new NodeRSA();
                         key.importKey({