+++ /dev/null
-;;; hashcash.el --- Add hashcash payments to email
-
-;; Copyright (C) 2003 Free Software Foundation
-;; Copyright (C) 1997--2002 Paul E. Foley
-
-;; Maintainer: Paul Foley <mycroft@actrix.gen.nz>
-;; Keywords: mail, hashcash
-
-;; Released under the GNU General Public License
-;; (http://www.gnu.org/licenses/gpl.html)
-
-;;; Commentary:
-
-;; The hashcash binary is at http://www.cypherspace.org/hashcash/
-;;
-;; Call mail-add-payment to add a hashcash payment to a mail message
-;; in the current buffer.
-;;
-;; To automatically add payments to all outgoing mail:
-;; (add-hook 'message-send-hook 'mail-add-payment)
-
-;;; Code:
-
-(eval-and-compile
- (autoload 'executable-find "executable"))
-
-(defcustom hashcash-default-payment 0
- "*The default number of bits to pay to unknown users.
-If this is zero, no payment header will be generated.
-See `hashcash-payment-alist'."
- :type 'integer)
-
-(defcustom hashcash-payment-alist '()
- "*An association list mapping email addresses to payment amounts.
-Elements may consist of (ADDR AMOUNT) or (ADDR STRING AMOUNT), where
-ADDR is the email address of the intended recipient and AMOUNT is
-the value of hashcash payment to be made to that user. STRING, if
-present, is the string to be hashed; if not present ADDR will be used.")
-
-(defcustom hashcash-default-accept-payment 10
- "*The default minimum number of bits to accept on incoming payments."
- :type 'integer)
-
-(defcustom hashcash-accept-resources `((,user-mail-address nil))
- "*An association list mapping hashcash resources to payment amounts.
-Resources named here are to be accepted in incoming payments. If the
-corresponding AMOUNT is NIL, the value of `hashcash-default-accept-payment'
-is used instead.")
-
-(defcustom hashcash-path (executable-find "hashcash")
- "*The path to the hashcash binary.")
-
-(defcustom hashcash-double-spend-database "hashcash.db"
- "*The path to the double-spending database.")
-
-(defcustom hashcash-in-news nil
- "*Specifies whether or not hashcash payments should be made to newsgroups."
- :type 'boolean)
-
-(require 'mail-utils)
-
-(eval-and-compile
- (if (fboundp 'point-at-bol)
- (defalias 'hashcash-point-at-bol 'point-at-bol)
- (defalias 'hashcash-point-at-bol 'line-beginning-position))
-
- (if (fboundp 'point-at-eol)
- (defalias 'hashcash-point-at-eol 'point-at-eol)
- (defalias 'hashcash-point-at-eol 'line-end-position)))
-
-(defun hashcash-strip-quoted-names (addr)
- (setq addr (mail-strip-quoted-names addr))
- (if (and addr (string-match "\\`\\([^+@]+\\)\\+[^@]*\\(@.+\\)" addr))
- (concat (match-string 1 addr) (match-string 2 addr))
- addr))
-
-(defun hashcash-payment-required (addr)
- "Return the hashcash payment value required for the given address."
- (let ((val (assoc addr hashcash-payment-alist)))
- (or (nth 2 val) (nth 1 val) hashcash-default-payment)))
-
-(defun hashcash-payment-to (addr)
- "Return the string with which hashcash payments should collide."
- (let ((val (assoc addr hashcash-payment-alist)))
- (or (nth 1 val) (nth 0 val) addr)))
-
-(defun hashcash-generate-payment (str val)
- "Generate a hashcash payment by finding a VAL-bit collison on STR."
- (if (> val 0)
- (save-excursion
- (set-buffer (get-buffer-create " *hashcash*"))
- (erase-buffer)
- (call-process hashcash-path nil t nil
- "-m" "-q" "-b" (number-to-string val) str)
- (goto-char (point-min))
- (buffer-substring (hashcash-point-at-bol) (hashcash-point-at-eol)))
- nil))
-
-(defun hashcash-check-payment (token str val)
- "Check the validity of a hashcash payment."
- (zerop (call-process hashcash-path nil nil nil "-c"
- "-d" "-f" hashcash-double-spend-database
- "-b" (number-to-string val)
- "-r" str
- token)))
-
-(defun hashcash-version (token)
- "Find the format version of a hashcash token."
- ;; Version 1.2 looks like n:yymmdd:rrrrr:xxxxxxxxxxxxxxxx
- ;; This carries its own version number embedded in the token,
- ;; so no further format number changes should be necessary
- ;; in the X-Payment header.
- ;;
- ;; Version 1.1 looks like yymmdd:rrrrr:xxxxxxxxxxxxxxxx
- ;; You need to upgrade your hashcash binary.
- ;;
- ;; Version 1.0 looked like nnnnnrrrrrxxxxxxxxxxxxxxxx
- ;; This is no longer supported.
- (cond ((equal (aref token 1) ?:) 1.2)
- ((equal (aref token 6) ?:) 1.1)
- (t (error "Unknown hashcash format version"))))
-
-;;;###autoload
-(defun hashcash-insert-payment (arg)
- "Insert X-Payment and X-Hashcash headers with a payment for ARG"
- (interactive "sPay to: ")
- (let ((pay (hashcash-generate-payment (hashcash-payment-to arg)
- (hashcash-payment-required arg))))
- (when pay
-; (insert-before-markers "X-Payment: hashcash "
-; (number-to-string (hashcash-version pay)) " "
-; pay "\n")
- (insert-before-markers "X-Hashcash: " pay "\n"))))
-
-;;;###autoload
-(defun hashcash-verify-payment (token &optional resource amount)
- "Verify a hashcash payment"
- (let ((key (if (< (hashcash-version token) 1.2)
- (nth 1 (split-string token ":"))
- (nth 2 (split-string token ":")))))
- (cond ((null resource)
- (let ((elt (assoc key hashcash-accept-resources)))
- (and elt (hashcash-check-payment token (car elt)
- (or (cadr elt) hashcash-default-accept-payment)))))
- ((equal token key)
- (hashcash-check-payment token resource
- (or amount hashcash-default-accept-payment)))
- (t nil))))
-
-;;;###autoload
-(defun mail-add-payment (&optional arg)
- "Add X-Payment: and X-Hashcash: headers with a hashcash payment
-for each recipient address. Prefix arg sets default payment temporarily."
- (interactive "P")
- (let ((hashcash-default-payment (if arg (prefix-numeric-value arg)
- hashcash-default-payment))
- (addrlist nil))
- (save-excursion
- (save-restriction
- (goto-char (point-min))
- (search-forward mail-header-separator)
- (beginning-of-line)
- (narrow-to-region (point-min) (point))
- (let ((to (hashcash-strip-quoted-names (mail-fetch-field "To" nil t)))
- (cc (hashcash-strip-quoted-names (mail-fetch-field "Cc" nil t)))
- (ng (hashcash-strip-quoted-names (mail-fetch-field "Newsgroups"
- nil t))))
- (when to
- (setq addrlist (split-string to ",[ \t\n]*")))
- (when cc
- (setq addrlist (nconc addrlist (split-string cc ",[ \t\n]*"))))
- (when (and hashcash-in-news ng)
- (setq addrlist (nconc addrlist (split-string ng ",[ \t\n]*")))))
- (when addrlist
- (mapcar #'hashcash-insert-payment addrlist))))) ; mapc
- t)
-
-;;;###autoload
-(defun mail-check-payment (&optional arg)
- "Look for a valid X-Payment: or X-Hashcash: header.
-Prefix arg sets default accept amount temporarily."
- (interactive "P")
- (let ((hashcash-default-accept-payment (if arg (prefix-numeric-value arg)
- hashcash-default-accept-payment))
- (version (hashcash-version (hashcash-generate-payment "x" 1))))
- (save-excursion
- (goto-char (point-min))
- (search-forward "\n\n")
- (beginning-of-line)
- (let ((end (point))
- (ok nil))
- (goto-char (point-min))
- (while (and (not ok) (search-forward "X-Payment: hashcash " end t))
- (let ((value (split-string
- (buffer-substring (point) (hashcash-point-at-eol))
- " ")))
- (when (equal (car value) (number-to-string version))
- (setq ok (hashcash-verify-payment (cadr value))))))
- (goto-char (point-min))
- (while (and (not ok) (search-forward "X-Hashcash: " end t))
- (setq ok (hashcash-verify-payment
- (buffer-substring (point) (hashcash-point-at-eol)))))
- (when ok
- (message "Payment valid"))
- ok))))
-
-(provide 'hashcash)
-
-;;; arch-tag: 0e7fe983-a124-4392-9788-0dbcbd2c4d62
projects / gnus / blobdiff