diff options
Diffstat (limited to 'lisp/net/ntlm.el')
| -rw-r--r-- | lisp/net/ntlm.el | 110 |
1 files changed, 85 insertions, 25 deletions
diff --git a/lisp/net/ntlm.el b/lisp/net/ntlm.el index ebcd21948bf..6d1cf2da71f 100644 --- a/lisp/net/ntlm.el +++ b/lisp/net/ntlm.el @@ -69,7 +69,6 @@ (require 'md4) (require 'hmac-md5) -(require 'calc) (defgroup ntlm nil "NTLM (NT LanManager) authentication." @@ -133,32 +132,93 @@ is not given." domain ;buffer field )))) -(defun ntlm-compute-timestamp () - "Compute an NTLMv2 timestamp. +;; Poor man's bignums: natural numbers represented as lists of bytes +;; in little-endian order. +;; When this code no longer needs to run on Emacs 26 or older, all this +;; silliness should be simplified to use ordinary Lisp integers. + +(eval-and-compile ; for compile-time simplification + (defun ntlm--bignat-of-int (x) + "Convert the natural number X into a bignat." + (declare (pure t)) + (and (not (zerop x)) + (cons (logand x #xff) (ntlm--bignat-of-int (ash x -8))))) + + (defun ntlm--bignat-add (a b &optional carry) + "Add the bignats A and B and the natural number CARRY." + (declare (pure t)) + (and (or a b (and carry (not (zerop carry)))) + (let ((s (+ (if a (car a) 0) + (if b (car b) 0) + (or carry 0)))) + (cons (logand s #xff) + (ntlm--bignat-add (cdr a) (cdr b) (ash s -8)))))) + + (defun ntlm--bignat-shift-left (x n) + "Multiply the bignat X by 2^{8N}." + (declare (pure t)) + (if (zerop n) x (ntlm--bignat-shift-left (cons 0 x) (1- n)))) + + (defun ntlm--bignat-mul-byte (a b) + "Multiply the bignat A with the byte B." + (declare (pure t)) + (let ((p (mapcar (lambda (x) (* x b)) a))) + (ntlm--bignat-add + (mapcar (lambda (x) (logand x #xff)) p) + (cons 0 (mapcar (lambda (x) (ash x -8)) p))))) + + (defun ntlm--bignat-mul (a b) + "Multiply the bignats A and B." + (declare (pure t)) + (and a b (ntlm--bignat-add (ntlm--bignat-mul-byte a (car b)) + (cons 0 (ntlm--bignat-mul a (cdr b)))))) + + (defun ntlm--bignat-of-string (s) + "Convert the string S (in decimal) to a bignat." + (declare (pure t)) + (ntlm--bignat-of-digits (reverse (string-to-list s)))) + + (defun ntlm--bignat-of-digits (digits) + "Convert the little-endian list DIGITS of decimal digits to a bignat." + (declare (pure t)) + (and digits + (ntlm--bignat-add + nil + (ntlm--bignat-mul-byte (ntlm--bignat-of-digits (cdr digits)) 10) + (- (car digits) ?0)))) + + (defun ntlm--bignat-to-int64 (x) + "Convert the bignat X to a 64-bit little-endian number as a string." + (declare (pure t)) + (apply #'unibyte-string (mapcar (lambda (n) (or (nth n x) 0)) + (number-sequence 0 7)))) + ) + +(defun ntlm--time-to-timestamp (time) + "Convert TIME to an NTLMv2 timestamp. Return a unibyte string representing the number of tenths of a microsecond since January 1, 1601 as a 64-bit little-endian -signed integer." - ;; FIXME: This can likely be significantly simplified using the new - ;; bignums support! - (let* ((s-to-tenths-of-us "mul(add(lsh($1,16),$2),10000000)") - (us-to-tenths-of-us "mul($3,10)") - (ps-to-tenths-of-us "idiv($4,100000)") - (tenths-of-us-since-jan-1-1601 - (apply #'calc-eval (concat "add(add(add(" - s-to-tenths-of-us "," - us-to-tenths-of-us ")," - ps-to-tenths-of-us ")," - ;; tenths of microseconds between - ;; 1601-01-01 and 1970-01-01 - "116444736000000000)") - 'rawnum (time-convert nil 'list))) - result-bytes) - (dotimes (_byte 8) - (push (calc-eval "and($1,16#FF)" 'rawnum tenths-of-us-since-jan-1-1601) - result-bytes) - (setq tenths-of-us-since-jan-1-1601 - (calc-eval "rsh($1,8,64)" 'rawnum tenths-of-us-since-jan-1-1601))) - (apply #'unibyte-string (nreverse result-bytes)))) +signed integer. TIME must be on the form (HIGH LOW USEC PSEC)." + (let* ((s-hi (ntlm--bignat-of-int (nth 0 time))) + (s-lo (ntlm--bignat-of-int (nth 1 time))) + (s (ntlm--bignat-add (ntlm--bignat-shift-left s-hi 2) s-lo)) + (us*10 (ntlm--bignat-of-int (* (nth 2 time) 10))) + (ps/1e5 (ntlm--bignat-of-int (/ (nth 3 time) 100000))) + ;; tenths of microseconds between 1601-01-01 and 1970-01-01 + (to-unix-epoch (ntlm--bignat-of-string "116444736000000000")) + (tenths-of-us-since-jan-1-1601 + (ntlm--bignat-add + (ntlm--bignat-add + (ntlm--bignat-add + (ntlm--bignat-mul s (ntlm--bignat-of-int 10000000)) + us*10) + ps/1e5) + to-unix-epoch))) + (ntlm--bignat-to-int64 tenths-of-us-since-jan-1-1601))) + +(defun ntlm-compute-timestamp () + "Current time as an NTLMv2 timestamp, as a unibyte string." + (ntlm--time-to-timestamp (time-convert nil 'list))) (defun ntlm-generate-nonce () "Generate a random nonce, not to be used more than once. |