[PATCH consfigurator 3/3] introduce the pass data store.

[David Bremner]

In this initial version, only IDEN1 of the form '--user-passwd-HOST' is
supported.
---
 consfigurator.asd  |  1 +
 src/data/pass.lisp | 60 ++++++++++++++++++++++++++++++++++++++++++++++
 src/package.lisp   |  3 +++
 3 files changed, 64 insertions(+)
 create mode 100644 src/data/pass.lisp

diff --git a/consfigurator.asd b/consfigurator.asd
index d159ba0..c542879 100644
--- a/consfigurator.asd
+++ b/consfigurator.asd
@@ -95,6 +95,7 @@
 	       (:file "src/data/gpgpubkeys")
                (:file "src/data/ssh-askpass")
                (:file "src/data/local-file")
+               (:file "src/data/pass")
                (:file "src/data/files-tree"))
   :in-order-to ((test-op (test-op "consfigurator/tests"))))
 
diff --git a/src/data/pass.lisp b/src/data/pass.lisp
new file mode 100644
index 0000000..fea1c3a
--- /dev/null
+++ b/src/data/pass.lisp
@@ -0,0 +1,60 @@
+;;; Consfigurator -- Lisp declarative configuration management system
+
+;;; Copyright (C) 2022  David Bremner <david at tethera.net>
+
+;;; This file is free software; you can redistribute it and/or modify
+;;; it under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3, or (at your option)
+;;; any later version.
+
+;;; This file is distributed in the hope that it will be useful,
+;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+
+;;; You should have received a copy of the GNU General Public License
+;;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+(in-package :consfigurator.data.pass)
+(named-readtables:in-readtable :consfigurator)
+
+(define-constant =prefix= "--user-passwd-" :test #'equal)
+
+(defun %read-gpg (location)
+  (string-right-trim
+   '(#\Return #\Newline)
+   (util:gpg-file-as-string location)))
+
+(defmethod register-data-source ((type (eql :pass)) &key (location "~/.password-store"))
+  "Provide the contents of a pass(1)  on the machine running the root
+Lisp.  Register this data source multiple times to provide multiple stores.
+
+LOCATION specifies the root of the password store.
+
+When retrieving a password, IDEN1 should be specified as `--user-passwd-HOST'
+and IDEN2 as username. HOST does not need to be an actual hostname and is
+interpreted as a directory in the password store. In particular HOST may
+contain one or more occurences of `/'."
+  (let ((base-path (ensure-directory-pathname (uiop:native-namestring location))))
+    (unless (directory-exists-p base-path)
+      (missing-data-source
+       "~A does not exist, or is not a directory." base-path))
+    (labels ((%make-path (iden1 iden2)
+               (when-let ((host (and (string-prefix-p =prefix= iden1)
+                                     (subseq iden1 (length =prefix=)))))
+                 (util:data-file-path base-path host iden2 :type "gpg")))
+             (check (iden1 iden2)
+               (when-let ((file-path (%make-path iden1 iden2)))
+                 (informat 4 "~&checking pass ~a ~a ~a" iden1 iden2 file-path)
+                 (and (file-exists-p file-path)
+                      (file-write-date file-path))))
+             (extract (iden1 iden2)
+               (when-let ((file-path (%make-path iden1 iden2)))
+                 (informat 4 "~&extracting from pass ~a ~a ~a" iden1 iden2 file-path)
+                 (and (file-exists-p file-path)
+                      (make-instance 'string-data
+                                     :string (%read-gpg file-path)
+                                     :iden1 iden1
+                                     :iden2 iden2
+                                     :version (file-write-date file-path))))))
+      (cons #'check #'extract))))
diff --git a/src/package.lisp b/src/package.lisp
index e8464a7..c4d834e 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -1022,5 +1022,8 @@
 
   (package :consfigurator.data.local-file)
 
+  (package :consfigurator.data.pass
+           (:local-nicknames (#:util  #:consfigurator.data.util)))
+
   (package :consfigurator.data.files-tree
            (:local-nicknames (#:util  #:consfigurator.data.util))))
-- 
2.34.1