[mrthankyou] smtplib partial modeling.

python/ql/src/experimental/semmle/python/libraries/SmtpLib.qll

@@ -0,0 +1,90 @@
+private import python
+private import semmle.python.dataflow.new.DataFlow
+private import experimental.semmle.python.Concepts
+private import semmle.python.ApiGraphs
+
+module SmtpLib {
+  private API::Node smtpLib() { result = API::moduleImport("smtplib") }
+
+  private API::Node smtpConnectionInstance() { result = smtpLib().getMember("SMTP_SSL") }
+
+  API::Node smtpMimeMultipartInstance() {
+    result = API::moduleImport("email.mime.multipart").getMember("MIMEMultipart")
+  }
+
+  API::Node smtpMimeTextInstance() {
+    result = API::moduleImport("email.mime.text").getMember("MIMEText")
+  }
+
+  DataFlow::Node smtpMimeTextHTMLInstance() {
+    // select SmtpLib::smtpMimeTextInstance().getAUse().getALocalSource().getACall()
+    exists(API::Node mimeTextInstance, DataFlow::CallCfgNode callNode |
+      mimeTextInstance = smtpMimeTextInstance().getReturn() and
+      callNode = mimeTextInstance.getACall() and
+      callNode.getArg(1).asExpr().(Unicode).getText() = "html" and
+      result = callNode
+    )
+  }
+
+  class SmtpLibSendMail extends DataFlow::CallCfgNode, EmailSender {
+    SmtpLibSendMail() { this = smtpConnectionInstance().getMember("sendmail").getACall() }
+
+    override DataFlow::Node getPlainTextBody() {
+      result in [this.getArg(1), this.getArgByName("message")]
+    }
+
+    override DataFlow::Node getHtmlBody() {
+      result in [this.getArg(8), this.getArgByName("html_message")]
+    }
+
+    override DataFlow::Node getTo() {
+      result in [this.getArg(3), this.getArgByName("recipient_list")]
+    }
+
+    override DataFlow::Node getFrom() {
+      result in [this.getArg(2), this.getArgByName("from_email")]
+    }
+
+    override DataFlow::Node getSubject() {
+      result in [this.getArg(0), this.getArgByName("subject")]
+    }
+  }
+}
+
+// MIMEMultipart has two ways it can add tainted data:
+//    MIMEMultipart(_subparts=(part1, part2))
+//    or
+//    message = MIMEMultipart("alternative")
+//    message.attach(part1)
+//
+//
+// select SmtpLib::smtpMimeTextHTMLInstance()
+// select API::moduleImport("email.mime.multipart")
+//       .getMember("MIMEMultipart")
+//       .getACall()
+//       .getArgByName("_subparts")
+//
+// from DataFlow::Node arg1
+// where
+//   arg1 =
+//     API::moduleImport("email.mime.multipart")
+//         .getMember("MIMEMultipart")
+//         .getReturn()
+//         .getMember("attach")
+//         .getACall()
+//         .getArg(0)
+//
+// select SmtpLib::smtpMimeTextHTMLInstance() //.getReturn()
+//
+//.getArg(1) //.getAUse()
+//
+// Work on the smtpMimeTextHTMLInstance function
+from DataFlow::CallCfgNode result1
+where
+  exists(API::Node mimeTextInstance, DataFlow::CallCfgNode callNode |
+    mimeTextInstance = SmtpLib::smtpMimeTextInstance().getReturn() and
+    callNode = mimeTextInstance.getACall() and
+    callNode.getArg(1).asExpr().(Unicode).getText() = "html" and
+    result1 = callNode
+  )
+select result1