From 6cbb431459e9a0db73264c4144937a136fdb5b83 Mon Sep 17 00:00:00 2001
From: Vineet Kumar <git@vineetk.net>
Date: Fri, 22 May 2026 16:45:27 -0400
Subject: add random password/username generation

---
 kasi.el | 55 ++++++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 44 insertions(+), 11 deletions(-)

diff --git a/kasi.el b/kasi.el
index f2ca588..1031afd 100644
--- a/kasi.el
+++ b/kasi.el
@@ -44,35 +44,68 @@
 
 (defvar kasi-version "1.0")
 
-(defun kasi-filename-short (file)
+(defun kasi--filename-short (file)
   "Returns shortened name of filename."
   (file-name-sans-extension
    (file-relative-name file kasi-dir)))
 
-(defun kasi-filename ()
+(defun kasi--filename ()
   "Returns full filename of the secret file."
   (let* ((filenames (file-expand-wildcards (format "%s/*/*" kasi-dir)))
 	 (options (mapcar (lambda (f)
-			    (kasi-filename-short f))
+			    (kasi--filename-short f))
 			  filenames))
 	 (selected (completing-read "File: " options))
 	 (file (elt filenames (seq-position options selected))))
     file))
 
-(defun kasi-get (file elem)
+(defun kasi--get (file elem)
   "Returns element from secret file."
   (car (with-temp-buffer
 	 (insert-file-contents file)
 	 (alist-get elem (read (current-buffer))))))
 
-(defun kasi-totp (file)
+(defun kasi--totp (file)
   "Returns current TOTP code from secret file."
-  (let* ((totp-secret (kasi-get file 'totp))
+  (let* ((totp-secret (kasi--get file 'totp))
 	 (totp-code (totp (base32-hex-decode totp-secret))))
     (kill-new totp-code)
     (message (format "TOTP %s for %s copied to kill ring"
 		     totp-code
-		     (kasi-filename-short file)))))
+		     (kasi--filename-short file)))))
+
+(defun kasi--random-string (length charset)
+   "Generate a random string of LENGTH using characters from CHARSET.
+Uses /dev/urandom for cryptographic security."
+   ;; I have not seen any other built-in way to get cryptographically
+   ;; random outputs in Emacs.
+   (let* ((bytes (with-temp-buffer
+                   (call-process "dd" nil (current-buffer) nil
+                                 "if=/dev/urandom" "bs=1" (format "count=%d" (* length 4)))
+                   (buffer-string)))
+          (charset-len (length charset))
+          (result ""))
+     (dotimes (i length)
+       (setq result (concat result
+			    (char-to-string
+			     (aref charset
+				   (% (aref bytes i)
+				      charset-len))))))
+     result))
+
+;;;###autoload
+(defun kasi-generate-password (&optional length)
+  "Generate a random password of LENGTH (default 32)."
+  (interactive "P")
+  (let ((charset "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789\"!#$%&'()*+,-./:;<=>?@[]^_`{|}~"))
+    (message (kasi--random-string (or length 32) charset))))
+
+;;;###autoload
+(defun kasi-generate-username (&optional length)
+  "Generate a random username of LENGTH (default 12)."
+  (interactive "P")
+  (let ((charset "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"))
+    (message (kasi--random-string (or length 12) charset))))
 
 ;;;###autoload
 (defun kasi (command file)
@@ -83,15 +116,15 @@
 						username
 						email
 						totp)))
-		     (kasi-filename)))
+		     (kasi--filename)))
   (pcase command
     ('edit (find-file-other-window file))
-    ('totp (kasi-totp file))
+    ('totp (kasi--totp file))
     ((or 'password 'username 'email)
      (progn
-       (kill-new (kasi-get file command))
+       (kill-new (kasi--get file command))
        (message (format "Copied %s for %s to kill ring."
 			command
-			(kasi-filename-short file)))))))
+			(kasi--filename-short file)))))))
 
 (provide 'kasi)
-- 
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