From 504e155f5de6f11a432ce963f4926b8d77a4bd8c Mon Sep 17 00:00:00 2001
From: Jaidyn Ann <10477760+JadedCtrl@users.noreply.github.com>
Date: Thu, 14 Sep 2023 18:45:03 -0500
Subject: [PATCH] Begin (provisional!!) RSA key management

---
 activitypub-servist.asd  |  2 +-
 activitypub-servist.lisp | 93 ++++++++++++++++++++++++++++++++++++++--
 2 files changed, 90 insertions(+), 5 deletions(-)

diff --git a/activitypub-servist.asd b/activitypub-servist.asd
index 41c10e7..f5d4343 100644
--- a/activitypub-servist.asd
+++ b/activitypub-servist.asd
@@ -1,3 +1,3 @@
 (defsystem "activitypub-servist"
-  :depends-on ("alexandria" "clack" "purl" "str" "webtentacle" "yason")
+  :depends-on ("alexandria" "clack" "inferior-shell" "ironclad" "purl" "str" "webtentacle" "yason")
   :components ((:file "activitypub-servist")))
diff --git a/activitypub-servist.lisp b/activitypub-servist.lisp
index 6da8db8..3408bcb 100644
--- a/activitypub-servist.lisp
+++ b/activitypub-servist.lisp
@@ -19,8 +19,6 @@
 
 (in-package #:activitypub-servist)
 
-;;(ql:quickload '(alexandria asn1 clack cl-base64 ironclad purl str trivia trivial-utf-8 webtentacle yason))
-
 
 (defun users ()
   "List of the server's usernames."
@@ -29,7 +27,7 @@
 
 (defun directories ()
   "Alist of the server's paths and their response functions."
-  '(("u/" . http-dir) (".well-known/webfinger" . http-webfinger)))
+  '(("u/" . http-user-dir) (".well-known/webfinger" . http-webfinger)))
 
 
 
@@ -131,7 +129,6 @@ the plist in the docstring for its WEBTENTACLE:SERVER function."
     ("404, you goddamn fool!")))
 
 
-
 ;; ————————————————————————————————————————
 ;; Invocation
 ;; ————————————————————————————————————————
@@ -204,3 +201,91 @@ or “/bear/apple/” or “/bear/”, but not “/bear” (not a directory)."
   "Split a pathname into a list of its components.
 “/u/bear/apple.txt” → '(“u” “bear” “apple.txt”)"
   (str:split #\/ pathname :omit-nulls 't))
+
+
+
+;; ————————————————————————————————————————
+;; RSA keys
+;; ————————————————————————————————————————
+;; At the moment, I’ve yet to use figure out how to create PEM representations of
+;; a public keypair properly in Lisp.
+;; So at the moment, keys are generated into PEM files by the openssl binary on
+;; the host’s system; and the output of the openssl command is used to parse into
+;; Ironclad keys.
+;; In the future, I’ll stop that. But at the moment,I want to focus on other core
+;; parts of ActivityPub; I’ve tired of messing with ASN1 & co.
+
+(defun parse-openssl-output (lines &optional (results '()))
+  "When passed the output of the shell command `openssl rsa -text -noout`, will
+parse the output into a plist containing relavent numbers:
+  :n (modulus), :e (public exponent), :d (private exponent), :p (1st prime),
+  :q (2nd prime), :e1 (1st exponent), :e2 (2nd exponent), and :c (coefficient)."
+  (let ((line (str:trim (car lines))))
+    (cond
+      ((not lines)
+       (mapcar
+        (lambda (result-item)
+          (if (stringp result-item)
+              (parse-integer (str:replace-all ":" "" result-item) :radix 16)
+              result-item))
+        results))
+      ((str:starts-with-p "Private" line)
+       (parse-openssl-output (cdr lines) results))
+      ((str:starts-with-p "modulus:" line)
+       (parse-openssl-output (cdr lines) (nconc results '(:n))))
+      ((str:starts-with-p "prime1" line)
+       (parse-openssl-output (cdr lines) (nconc results '(:p))))
+      ((str:starts-with-p "prime2" line)
+       (parse-openssl-output (cdr lines) (nconc results '(:q))))
+      ((str:starts-with-p "exponent1" line)
+       (parse-openssl-output (cdr lines) (nconc results '(:e1))))
+      ((str:starts-with-p "exponent2" line)
+       (parse-openssl-output (cdr lines) (nconc results '(:e2))))
+      ((str:starts-with-p "coefficient" line)
+       (parse-openssl-output (cdr lines) (nconc results '(:c))))
+      ((str:starts-with-p "privateExponent" line)
+       (parse-openssl-output (cdr lines) (nconc results '(:d))))
+      ((str:starts-with-p "publicExponent" line)
+       (parse-openssl-output
+        (cdr lines)
+        (nconc
+         results
+         (list
+          :e
+          (parse-integer
+           (car (str:split #\space
+                           (str:replace-first
+                            "publicExponent: "
+                            ""
+                            line))))))))
+      ('t
+       (let* ((last-element (car (last results)))
+              (total-string (if (stringp last-element)
+                                (str:concat last-element line)
+                                line)))
+         (parse-openssl-output (cdr lines)
+                               (if (stringp last-element)
+                                   (nconc (reverse (cdr (reverse results)))
+                                          (list total-string))
+                                   (nconc results
+                                          (list total-string)))))))))
+
+
+(defun openssl-shell-pem-keypair (pem-file)
+  "Given a private RSA PEM file, this will parse it into two returned values:
+An Ironclad private key, and an Ironclad public key."
+  (let ((key-values
+          (parse-openssl-output
+           (inferior-shell:run/lines
+            (str:concat "openssl rsa -text -noout -in " pem-file)))))
+    (values (ironclad:make-private-key
+             :rsa
+             :n (getf key-values :n)
+             :e (getf key-values :e)
+             :d (getf key-values :d)
+             :p (getf key-values :p)
+             :q (getf key-values :q))
+            (ironclad:make-public-key
+                         :rsa
+                         :n (getf key-values :n)
+                         :e (getf key-values :e)))))