add support for node-rsa

Author: erik-krogh

javascript/ql/lib/semmle/javascript/frameworks/CryptoLibraries.qll

@@ -689,3 +689,28 @@ private module ExpressJwt {
     Key() { this = DataFlow::moduleMember("express-jwt", "sign").getACall().getArgument(1) }
   }
 }
+
+/**
+ * Provides classes for working with the `node-rsa` package (https://www.npmjs.com/package/node-rsa)
+ */
+private module NodeRsa {
+  private class CreateKey extends CryptographicKeyCreation, API::InvokeNode {
+    CryptographicAlgorithm algorithm;
+
+    CreateKey() {
+      this = API::moduleImport("node-rsa").getAnInstantiation()
+      or
+      this = API::moduleImport("node-rsa").getInstance().getMember("generateKeyPair").getACall()
+    }
+
+    override CryptographicAlgorithm getAlgorithm() { result.matchesName("rsa") }
+
+    override int getSize() {
+      result = this.getArgument(0).getIntValue()
+      or
+      result = this.getOptionArgument(0, "b").getIntValue()
+    }
+
+    override predicate isSymmetricKey() { none() }
+  }
+}

javascript/ql/test/query-tests/Security/CWE-326/InsufficientKeySize.expected

@@ -6,3 +6,6 @@
 | tst.js:19:12:19:57 | forge.r ... rd, 64) | Creation of an symmetric RC2 key uses 64 bits, which is below 128 and considered breakable. |
 | tst.js:26:12:26:53 | forge.c ... , key2) | Creation of an symmetric AESCBC key uses 64 bits, which is below 128 and considered breakable. |
 | tst.js:30:12:30:56 | forge.c ... , key3) | Creation of an symmetric 3DESCBC key uses 64 bits, which is below 128 and considered breakable. |
+| tst.js:35:13:35:43 | crypto. ... an(512) | Creation of an asymmetric key uses 512 bits, which is below 2048 and considered breakable. |
+| tst.js:39:13:39:33 | new Nod ... : 512}) | Creation of an asymmetric RSA key uses 512 bits, which is below 2048 and considered breakable. |
+| tst.js:43:1:43:31 | key.gen ...  65537) | Creation of an asymmetric RSA key uses 512 bits, which is below 2048 and considered breakable. |

javascript/ql/test/query-tests/Security/CWE-326/tst.js

@@ -33,4 +33,12 @@ var key4 = myBuffer.getBytes(16);
 var good5 = forge.cipher.createDecipher('AES-CBC', key4); // OK
 
 var bad10 = crypto.createDiffieHellman(512);
-var good6 = crypto.createDiffieHellman(2048);
+var good6 = crypto.createDiffieHellman(2048);
+
+const NodeRSA = require('node-rsa');
+var bad11 = new NodeRSA({b: 512}); // NOT OK
+var good7 = new NodeRSA({b: 4096}); // OK
+
+var key = new NodeRSA(); // OK
+key.generateKeyPair(512, 65537); // NOT OK
+key.generateKeyPair(4096, 65537); // OK