jv@mh.nl (Johan Vromans) (05/14/91)
Submitted-by: Johan Vromans <jv@mh.nl> Posting-number: Volume 19, Issue 62 Archive-name: md4.el/part01 md4.el defines the functions to have automatic validation and insertion of MD4 signatures using GNUS. Johan ----- #!/bin/sh # This is a shell archive (produced by shar 3.49) # To extract the files from this archive, save it to a file, remove # everything above the "!/bin/sh" line above, and type "sh file_name". # # made 05/11/1991 14:27 UTC by jv@pronto # Source directory /u1/users/jv # # existing files will NOT be overwritten unless -c is specified # # This shar contains: # length mode name # ------ ---------- ------------------------------------------ # 4010 -r--r--r-- md4.el # # ============= md4.el ============== if test -f 'md4.el' -a X"$1" != X"-c"; then echo 'x - skipping md4.el (File already exists)' else echo 'x - extracting md4.el (Text)' sed 's/^X//' << 'SHAR_EOF' > 'md4.el' && X;; @(#)@ md4 1.1 - MD4 support for GNUS X;; X;; This file defines functions to calculate a MD4 signature, add X;; it to outgoing postings, and validate it on incoming postings. X;; X;; It uses "gnus-Inews-article-hook", called by GNUS just before passing X;; the articel to inews, to install the signature. X;; X;; "gnus-Article-prepare-hook" is used to validate the signature on X;; an article if you read it. X;; X;; This file, if useful, is covered by the GPL. X;; X;; Johan Vromans <jv@mh.nl> X X;; Customizations X X(defvar md4-command "md4" "*Where to find md4") X X(defvar md4-signature-header "X-Md4-Signature") X X(defvar md4-insertion t X "*Controls MD4 signature insertion. If nil, no signature is X calculated nor inserted.") X X(defvar md4-validation 1 X "*Controls MD4 signature validation. If nil, no validation is X performed. If t, validation is performed, and failures are reported. X Any other value causes validation to be performed, and failures as X well as successes to be reported.") X X;; Hook definitions and insertions. X X(add-hook 'gnus-Inews-article-hook 'md4-add-signature) X(add-hook 'gnus-Article-prepare-hook 'md4-validate-signature) X;; X;; Calcuates the MD4 signature for the article to be posted, which X;; is assumed to be in the current buffer. X;; X(defun md4-add-signature () X "Adds a MD4-signature to the article being posted. Must be called Xfrom gnus-Inews-article-hook." X (interactive) X X (if (null md4-insertion) X nil X (let (start-of-body end-of-body sigfile) X X ;; .signature handling. may be system specific X (goto-char (point-max)) X (setq end-of-body (point-marker)) X (if (file-exists-p X (setq sigfile X (or gnus-signature-file (expand-file-name "~/.signature")))) X (progn X (insert "-- \n") ; that is what I get inserted... X (insert-file sigfile)) X (setq sigfile nil)) X X (goto-char (point-min)) X (search-forward "\n\n") X (setq start-of-body (point-marker)) ; remember where X X ;; Run md4 and add the signature. X (forward-line -1) X (insert md4-signature-header ": ") X (insert (md4-signature-region start-of-body (point-max))) X (insert "\n") X X (if sigfile X (delete-region end-of-body (point-max))) X ))) X X;; X;; Validate MD4 signature. A message is shown with the result. X;; If the signature does not match, buffer "*MD4 Buffer*" holds more X;; information. X;; X(defun md4-validate-signature () X "Checks a MD4-signature in the article being read. May be called Xfrom gnus-article-prepare-hook." X (interactive) X X (if (null md4-validation) X nil X (let (start-of-body) X (goto-char (point-min)) X (search-forward "\n\n") X (setq start-of-body (point-marker)) ; remember where X X ;; Check if a signature header is present X (goto-char (point-min)) X (if (search-forward X (concat "\n" md4-signature-header ": ") X start-of-body t) X (let (signature (here (point))) X (forward-line 1) X (setq signature (buffer-substring here (1- (point)))) X X ;; Validate X (if (string= X signature X (md4-signature-region start-of-body (point-max))) X (progn X (if (not (equal md4-validation t)) X (message "MD4 signature valid.")) X (bury-buffer md4-buffer)) X (beep) X (save-excursion X (set-buffer md4-buffer) X (goto-char (point-min)) X (insert (message "MD4 signature mismatch!") X "\nPosted: " signature X "\nCalculated: ") X (goto-char (point-min)))) X ))))) X X(defun md4-signature-region (start end) X "Calculates MD4 signature." X X ;; Get buffer and clear it X (setq md4-buffer (get-buffer-create "*MD4 Buffer*")) X (save-excursion X (set-buffer md4-buffer) X (erase-buffer)) X X ;; Run md4 X (call-process-region start end X md4-command nil md4-buffer nil) X X ;; Verify normal result X (save-excursion X (set-buffer md4-buffer) X (if (= (buffer-size) 33) X (buffer-substring (point-min) (1- (point-max))) X (error "Unexpected result from %s: %s" md4-command X (buffer-substring (point-min) (point-max)))))) SHAR_EOF chmod 0444 md4.el || echo 'restore of md4.el failed' Wc_c="`wc -c < 'md4.el'`" test 4010 -eq "$Wc_c" || echo 'md4.el: original size 4010, current size' "$Wc_c" fi exit 0 -- Kent Landfield INTERNET: kent@sparky.IMD.Sterling.COM Sterling Software, IMD UUCP: uunet!sparky!kent Phone: (402) 291-8300 FAX: (402) 291-4362 Please send comp.sources.misc-related mail to kent@uunet.uu.net. exit 0 # Just in case... -- Kent Landfield INTERNET: kent@sparky.IMD.Sterling.COM Sterling Software, IMD UUCP: uunet!sparky!kent Phone: (402) 291-8300 FAX: (402) 291-4362 Please send comp.sources.misc-related mail to kent@uunet.uu.net.