Add new post.

wmealing · Sep 12, 2024 · 74bd6f2 · 74bd6f2
1 parent 0fbe62b
commit 74bd6f2
Show file tree

Hide file tree

Showing 3 changed files with 279 additions and 1 deletion.
diff --git a/sending-email-in-common-lisp.html b/sending-email-in-common-lisp.html
diff --git a/sending-email-in-common-lisp.org b/sending-email-in-common-lisp.org
@@ -0,0 +1,101 @@
+#+TITLE: Sending email in common-lisp
+
+#+OPTIONS: ^:nil num:nil toc:nil date:nil author:nil html-postamble:nil
+#+SETUPFILE: "./setupfile.org"
+#+HTML_HEAD: <meta name="description" content="Wade Mealings documentation" />
+
+* Summary:
+
+This page covers how to send an email from your common-lisp coding using the cl-smtp library using googles gmail servers.
+
+
+* Introduction
+
+This post covers a working example on how to send email from the common-lisp (cl) language using googles servers.  The provided
+example has been tested as an individual, and regularly used from the 'google workspace' account.
+
+
+* Requirements:
+
+
+   An Application password.
+
+   [[https://knowledge.workspace.google.com/kb/how-to-create-app-passwords-000009237][Google detailed getting one here.]]  One fact that was missed is that you now need 2FA
+   configured for the account or you can not make app passwords.
+
+
+* Ideas for improvement.
+
+** 1. Secret Storage mechanism.
+
+   The application password needs to be stored somewhere, my advice is not to have it stored in plaintext.
+
+   If your application is hosted on a containerized platform, you can pass it as environment variables, or
+   some of them have secrets file. 
+
+** 2. Preventing secret leaks.
+
+   After the secret is loaded into memory, destroy the file or environment setting so it is harder for attackers
+   to abuse the information.
+
+   #+BEGIN_SRC lisp
+  (setf (uiop:getenv "SOME_ENVIRONMENT_VARIABLE") "PASSWORD-REMOVED-FOR-SECURITY-REASONS")
+   #+END_SRC
+
+   When it is loaded, use  [[https://github.com/rotatef/secret-values][Secret Values]] which will prevent passwords appearing in backtraces or logs.
+
+** 3. Preventing accidental/intention spamming.
+
+   Your application may accidentally send out hundreds of mail if a function is run repeatedly accidentally.
+   It is important that the program keep an accurate, reliable mechanism to know when a limits are abused.
+
+
+* The code:
+:LOGBOOK:
+- Note taken on [2024-09-13 Fri 00:25]
+:END:
+
+   Listed below is the common-lisp code that is required to send email.   The "password" is stored
+   in the environment variable GMAIL_KEY, as a single string.  Google often displays on the 'app password'
+   page as 4 sets of 4 characters, aka xxxx xxxx xxxx xxxx , however experience shows that there was no space required.
+
+   #+BEGIN_SRC lisp
+
+     (ql:quickload "cl-smtp")
+     (ql:quickload "cl-mime")
+
+     (defun email-report (&key to cc subject html)
+            "Generic send SMTP mail with some TEXT to RECIEPIENTS"
+            (let ((from "[email protected]")
+                  (login "[email protected]")
+                  (passwd (uiop:getenv "GMAIL_KEY")))
+
+              (cl-smtp:with-smtp-mail (out "smtp.gmail.com" to cc
+                                           :ssl :tls
+                                           :authentication `(,login ,passwd))
+
+                (format out "To: ~A~%" to )
+                (format out "Subject: ~A~%" subject)
+
+                (cl-mime:print-mime out (make-instance 'cl-mime:mime
+                                                       :type "text" :subtype "html"
+                                                       :encoding :base64
+                                                       :content html) t t))))
+
+     (devar html-mail-content "<html><h1> THis is html, but not really. </h1></html>")
+
+     (email-report :to "[email protected]"
+                   :cc *cc-list*
+                   :subject email-subject
+                   :html html-content)
+   #+END_SRC
+
+* Conclusion
+
+This example works for both personal and google workspace accounts. 
+
+
+
+* Resources:
+
+https://gitlab.common-lisp.net/cl-smtp/cl-smtp
diff --git a/setupfile.org b/setupfile.org
@@ -9,4 +9,9 @@
 #+HTML_HEAD:  <link rel="stylesheet" href="reset.css">
 #+HTML_HEAD:  <link rel="stylesheet" href="index.css">
 #+HTML_HEAD: <meta name="author" content="Wade Mealing" />
-#+HTML_HEAD_EXTRA: <meta http-equiv="Content-Security-Policy"  content="default-src 'self' 'unsafe-inline'; img-src https://*; child-src 'none';" />
+--- #+HTML_HEAD_EXTRA: <meta http-equiv="Content-Security-Policy"  content="default-src 'self' 'unsafe-inline'; img-src https://*; child-src 'none';" />
+#+HTML_HEAD_EXTRA: <meta http-equiv="Content-Security-Policy"  content="script-src 'self' ajax.googleapis.com;"" />
+
+
+
+*