Python: Pycurl SSL Disabled

Author: Porcupiney Hairs

python/ql/lib/semmle/python/frameworks/Pycurl.qll

@@ -37,6 +37,15 @@ module Pycurl {
     /** Gets a reference to an instance of `pycurl.Curl`. */
     private API::Node instance() { result = classRef().getReturn() }
 
+    /** Gets a reference to an instance of `pycurl.Curl.setopt`. */
+    private API::Node setopt() { result = instance().getMember("setopt") }
+
+    /** Gets a reference to an instance of `pycurl.Curl.SSL_VERIFYPEER`. */
+    private API::Node sslverifypeer() {
+      result = API::moduleImport("pycurl").getMember("SSL_VERIFYPEER") or
+      result = instance().getMember("SSL_VERIFYPEER")
+    }
+
     /**
      * When the first parameter value of the `setopt` function is set to `pycurl.URL`,
      * the second parameter value is the request resource link.
@@ -45,7 +54,7 @@ module Pycurl {
      */
     private class OutgoingRequestCall extends Http::Client::Request::Range, DataFlow::CallCfgNode {
       OutgoingRequestCall() {
-        this = instance().getMember("setopt").getACall() and
+        this = setopt().getACall() and
         this.getArg(0).asCfgNode().(AttrNode).getName() = "URL"
       }
 
@@ -58,9 +67,41 @@ module Pycurl {
       override predicate disablesCertificateValidation(
         DataFlow::Node disablingNode, DataFlow::Node argumentOrigin
       ) {
-        // TODO: Look into disabling certificate validation
         none()
       }
     }
+
+    /**
+     * When the first parameter value of the `setopt` function is set to `SSL_VERIFYPEER` or `SSL_VERIFYHOST`,
+     * the second parameter value disables or enable SSL certifiacte verification.
+     *
+     * See http://pycurl.io/docs/latest/curlobject.html#pycurl.Curl.setopt.
+     */
+    private class CurlSslCall extends Http::Client::Request::Range, DataFlow::CallCfgNode {
+      CurlSslCall() {
+        this = setopt().getACall() and
+        this.getArg(0).asCfgNode().(AttrNode).getName() = ["SSL_VERIFYPEER", "SSL_VERIFYHOST"]
+      }
+
+      override DataFlow::Node getAUrlPart() { none() }
+
+      override string getFramework() { result = "pycurl.Curl" }
+
+      override predicate disablesCertificateValidation(
+        DataFlow::Node disablingNode, DataFlow::Node argumentOrigin
+      ) {
+        exists(API::CallNode c |
+          c = setopt().getACall() and
+          sslverifypeer().getAValueReachableFromSource() = c.getArg(0) and
+          (
+            exists(IntegerLiteral i | i.getValue() = 0 and c.getArg(1).asExpr() = i)
+            or
+            exists(BooleanLiteral b | b.booleanValue() = false)
+          )
+        |
+          disablingNode = c and argumentOrigin = c.getArg(1)
+        )
+      }
+    }
   }
 }