1 ;;; ntlm.el --- NTLM (NT LanManager) authentication support
3 ;; Copyright (C) 2001 Taro Kawagishi
4 ;; Author: Taro Kawagishi <tarok@transpulse.org>
5 ;; Keywords: NTLM, SASL
7 ;; Created: February 2001
9 ;; This program is free software; you can redistribute it and/or modify
10 ;; it under the terms of the GNU General Public License as published by
11 ;; the Free Software Foundation; either version 2, or (at your option)
14 ;; This program is distributed in the hope that it will be useful,
15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 ;; GNU General Public License for more details.
19 ;; You should have received a copy of the GNU General Public License
20 ;; along with this program; see the file COPYING. If not, write to the
21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
22 ;; Boston, MA 02111-1307, USA.
26 ;; This library is a direct translation of the Samba release 2.2.0
27 ;; implementation of Windows NT and LanManager compatible password
30 ;; Interface functions:
32 ;; ntlm-build-auth-request
33 ;; This will return a binary string, which should be used in the
34 ;; base64 encoded form and it is the caller's responsibility to encode
35 ;; the returned string with base64.
37 ;; ntlm-build-auth-response
38 ;; It is the caller's responsibility to pass a base64 decoded string
39 ;; (which will be a binary string) as the first argument and to
40 ;; encode the returned string with base64. The second argument user
41 ;; should be given in user@domain format.
43 ;; ntlm-get-password-hashes
46 ;; NTLM authentication procedure example:
48 ;; 1. Open a network connection to the Exchange server at the IMAP port (143)
49 ;; 2. Receive an opening message such as:
50 ;; "* OK Microsoft Exchange IMAP4rev1 server version 5.5.2653.7 (XXXX) ready"
51 ;; 3. Ask for IMAP server capability by sending "NNN capability"
52 ;; 4. Receive a capability message such as:
53 ;; "* CAPABILITY IMAP4 IMAP4rev1 IDLE LITERAL+ LOGIN-REFERRALS MAILBOX-REFERRALS NAMESPACE AUTH=NTLM"
54 ;; 5. Ask for NTLM authentication by sending a string
55 ;; "NNN authenticate ntlm"
56 ;; 6. Receive continuation acknowledgment "+"
57 ;; 7. Send NTLM authentication request generated by 'ntlm-build-auth-request
58 ;; 8. Receive NTLM challenge string following acknowledgment "+"
59 ;; 9. Generate response to challenge by 'ntlm-build-auth-response
60 ;; (here two hash function values of the user password are encrypted)
61 ;; 10. Receive authentication completion message such as
62 ;; "NNN OK AUTHENTICATE NTLM completed."
69 ;;; NTLM authentication interface functions
71 (defun ntlm-build-auth-request (user &optional domain)
72 "Return the NTLM authentication request string for USER and DOMAIN.
73 USER is a string representing a user name to be authenticated and
74 DOMAIN is a NT domain. USER can include a NT domain part as in
75 user@domain where the string after @ is used as the domain if DOMAIN
78 (let ((request-ident (concat "NTLMSSP" (make-string 1 0)))
79 (request-msgType (concat (make-string 1 1) (make-string 3 0)))
81 (request-flags (concat (make-string 1 7) (make-string 1 178)
85 (when (string-match "@" user)
87 (setq domain (substring user (1+ (match-beginning 0)))))
88 (setq user (substring user 0 (match-beginning 0))))
89 ;; set fields offsets within the request struct
90 (setq lu (length user))
91 (setq ld (length domain))
92 (setq off-u 32) ;offset to the string 'user
93 (setq off-d (+ 32 lu)) ;offset to the string 'domain
94 ;; pack the request struct in a string
95 (concat request-ident ;8 bytes
96 request-msgType ;4 bytes
97 request-flags ;4 bytes
98 (md4-pack-int16 lu) ;user field, count field
99 (md4-pack-int16 lu) ;user field, max count field
100 (md4-pack-int32 (cons 0 off-u)) ;user field, offset field
101 (md4-pack-int16 ld) ;domain field, count field
102 (md4-pack-int16 ld) ;domain field, max count field
103 (md4-pack-int32 (cons 0 off-d)) ;domain field, offset field
108 (defun ntlm-build-auth-response (challenge user password-hashes)
109 "Return the response string to a challenge string CHALLENGE given by
110 the NTLM based server for the user USER and the password hash list
111 PASSWORD-HASHES. NTLM uses two hash values which are represented
112 by PASSWORD-HASHES. PASSWORD-HASHES should be a return value of
113 (list (ntlm-smb-passwd-hash password) (ntlm-md4hash password))"
114 (let* ((rchallenge (string-as-unibyte challenge))
115 ;; get fields within challenge struct
116 ;;(ident (substring rchallenge 0 8)) ;ident, 8 bytes
117 ;;(msgType (substring rchallenge 8 12)) ;msgType, 4 bytes
118 (uDomain (substring rchallenge 12 20)) ;uDomain, 8 bytes
119 (flags (substring rchallenge 20 24)) ;flags, 4 bytes
120 (challengeData (substring rchallenge 24 32)) ;challengeData, 8 bytes
121 uDomain-len uDomain-offs
122 ;; response struct and its fields
123 lmRespData ;lmRespData, 24 bytes
124 ntRespData ;ntRespData, 24 bytes
125 domain ;ascii domain string
126 lu ld off-lm off-nt off-d off-u off-w off-s)
127 ;; extract domain string from challenge string
128 (setq uDomain-len (md4-unpack-int16 (substring uDomain 0 2)))
129 (setq uDomain-offs (md4-unpack-int32 (substring uDomain 4 8)))
131 (ntlm-unicode2ascii (substring challenge
133 (+ (cdr uDomain-offs) uDomain-len))
135 ;; overwrite domain in case user is given in <user>@<domain> format
136 (when (string-match "@" user)
137 (setq domain (substring user (1+ (match-beginning 0))))
138 (setq user (substring user 0 (match-beginning 0))))
140 ;; generate response data
142 (ntlm-smb-owf-encrypt (car password-hashes) challengeData))
144 (ntlm-smb-owf-encrypt (cadr password-hashes) challengeData))
146 ;; get offsets to fields to pack the response struct in a string
147 (setq lu (length user))
148 (setq ld (length domain))
149 (setq off-lm 64) ;offset to string 'lmResponse
150 (setq off-nt (+ 64 24)) ;offset to string 'ntResponse
151 (setq off-d (+ 64 48)) ;offset to string 'uDomain
152 (setq off-u (+ 64 48 (* 2 ld))) ;offset to string 'uUser
153 (setq off-w (+ 64 48 (* 2 (+ ld lu)))) ;offset to string 'uWks
154 (setq off-s (+ 64 48 (* 2 (+ ld lu lu)))) ;offset to string 'sessionKey
155 ;; pack the response struct in a string
156 (concat "NTLMSSP\0" ;response ident field, 8 bytes
157 (md4-pack-int32 '(0 . 3)) ;response msgType field, 4 bytes
159 ;; lmResponse field, 8 bytes
160 ;;AddBytes(response,lmResponse,lmRespData,24);
161 (md4-pack-int16 24) ;len field
162 (md4-pack-int16 24) ;maxlen field
163 (md4-pack-int32 (cons 0 off-lm)) ;field offset
165 ;; ntResponse field, 8 bytes
166 ;;AddBytes(response,ntResponse,ntRespData,24);
167 (md4-pack-int16 24) ;len field
168 (md4-pack-int16 24) ;maxlen field
169 (md4-pack-int32 (cons 0 off-nt)) ;field offset
171 ;; uDomain field, 8 bytes
172 ;;AddUnicodeString(response,uDomain,domain);
173 ;;AddBytes(response, uDomain, udomain, 2*ld);
174 (md4-pack-int16 (* 2 ld)) ;len field
175 (md4-pack-int16 (* 2 ld)) ;maxlen field
176 (md4-pack-int32 (cons 0 off-d)) ;field offset
178 ;; uUser field, 8 bytes
179 ;;AddUnicodeString(response,uUser,u);
180 ;;AddBytes(response, uUser, uuser, 2*lu);
181 (md4-pack-int16 (* 2 lu)) ;len field
182 (md4-pack-int16 (* 2 lu)) ;maxlen field
183 (md4-pack-int32 (cons 0 off-u)) ;field offset
185 ;; uWks field, 8 bytes
186 ;;AddUnicodeString(response,uWks,u);
187 (md4-pack-int16 (* 2 lu)) ;len field
188 (md4-pack-int16 (* 2 lu)) ;maxlen field
189 (md4-pack-int32 (cons 0 off-w)) ;field offset
191 ;; sessionKey field, 8 bytes
192 ;;AddString(response,sessionKey,NULL);
193 (md4-pack-int16 0) ;len field
194 (md4-pack-int16 0) ;maxlen field
195 (md4-pack-int32 (cons 0 (- off-s off-lm))) ;field offset
197 ;; flags field, 4 bytes
201 lmRespData ;lmResponse, 24 bytes
202 ntRespData ;ntResponse, 24 bytes
203 (ntlm-ascii2unicode domain ;unicode domain string, 2*ld bytes
205 (ntlm-ascii2unicode user ;unicode user string, 2*lu bytes
207 (ntlm-ascii2unicode user ;unicode user string, 2*lu bytes
211 (defun ntlm-get-password-hashes (password)
212 "Return a pair of SMB hash and NT MD4 hash of the given password PASSWORD"
213 (list (ntlm-smb-passwd-hash password)
214 (ntlm-md4hash password)))
216 (defun ntlm-ascii2unicode (str len)
217 "Convert an ASCII string into a NT Unicode string, which is
218 little-endian utf16."
219 (let ((utf (make-string (* 2 len) 0)) (i 0) val)
220 (while (and (< i len)
221 (not (zerop (setq val (aref str i)))))
222 (aset utf (* 2 i) val)
223 (aset utf (1+ (* 2 i)) 0)
227 (defun ntlm-unicode2ascii (str len)
228 "Extract 7 bits ASCII part of a little endian utf16 string STR of length LEN."
229 (let ((buf (make-string len 0)) (i 0) (j 0))
231 (aset buf i (logand (aref str j) 127)) ;(string-to-number "7f" 16)
236 (defun ntlm-smb-passwd-hash (passwd)
237 "Return the SMB password hash string of 16 bytes long for the given password
238 string PASSWD. PASSWD is truncated to 14 bytes if longer."
239 (let ((len (min (length passwd) 14)))
241 (concat (substring (upcase passwd) 0 len) ;fill top 14 bytes with passwd
242 (make-string (- 15 len) 0)))))
244 (defun ntlm-smb-owf-encrypt (passwd c8)
245 "Return the response string of 24 bytes long for the given password
246 string PASSWD based on the DES encryption. PASSWD is of at most 14
247 bytes long and the challenge string C8 of 8 bytes long."
248 (let ((len (min (length passwd) 16)) p22)
249 (setq p22 (concat (substring passwd 0 len) ;fill top 16 bytes with passwd
250 (make-string (- 22 len) 0)))
251 (ntlm-smb-des-e-p24 p22 c8)))
253 (defun ntlm-smb-des-e-p24 (p22 c8)
254 "Return a 24 bytes hashed string for a 21 bytes string P22 and a 8 bytes
256 (concat (ntlm-smb-hash c8 p22 t) ;hash first 8 bytes of p22
257 (ntlm-smb-hash c8 (substring p22 7) t)
258 (ntlm-smb-hash c8 (substring p22 14) t)))
260 (defconst ntlm-smb-sp8 [75 71 83 33 64 35 36 37])
262 (defun ntlm-smb-des-e-p16 (p15)
263 "Return a 16 bytes hashed string for a 15 bytes string P15."
264 (concat (ntlm-smb-hash ntlm-smb-sp8 p15 t) ;hash of first 8 bytes of p15
265 (ntlm-smb-hash ntlm-smb-sp8 ;hash of last 8 bytes of p15
266 (substring p15 7) t)))
268 (defun ntlm-smb-hash (in key forw)
269 "Return the hash string of length 8 for a string IN of length 8 and
270 a string KEY of length 8. FORW is t or nil."
271 (let ((out (make-string 8 0))
272 outb ;string of length 64
273 (inb (make-string 64 0))
274 (keyb (make-string 64 0))
275 (key2 (ntlm-smb-str-to-key key))
278 (unless (zerop (logand (aref in (/ i 8)) (lsh 1 (- 7 (% i 8)))))
280 (unless (zerop (logand (aref key2 (/ i 8)) (lsh 1 (- 7 (% i 8)))))
283 (setq outb (ntlm-smb-dohash inb keyb forw))
286 (unless (zerop (aref outb i))
287 (setq aa (aref out (/ i 8)))
289 (logior aa (lsh 1 (- 7 (% i 8))))))
293 (defun ntlm-smb-str-to-key (str)
294 "Return a string of length 8 for the given string STR of length 7."
295 (let ((key (make-string 8 0))
297 (aset key 0 (lsh (aref str 0) -1))
299 (lsh (logand (aref str 0) 1) 6)
300 (lsh (aref str 1) -2)))
302 (lsh (logand (aref str 1) 3) 5)
303 (lsh (aref str 2) -3)))
305 (lsh (logand (aref str 2) 7) 4)
306 (lsh (aref str 3) -4)))
308 (lsh (logand (aref str 3) 15) 3)
309 (lsh (aref str 4) -5)))
311 (lsh (logand (aref str 4) 31) 2)
312 (lsh (aref str 5) -6)))
314 (lsh (logand (aref str 5) 63) 1)
315 (lsh (aref str 6) -7)))
316 (aset key 7 (logand (aref str 6) 127))
318 (aset key i (lsh (aref key i) 1))
322 (defconst ntlm-smb-perm1 [57 49 41 33 25 17 9
331 (defconst ntlm-smb-perm2 [14 17 11 24 1 5
340 (defconst ntlm-smb-perm3 [58 50 42 34 26 18 10 2
341 60 52 44 36 28 20 12 4
342 62 54 46 38 30 22 14 6
343 64 56 48 40 32 24 16 8
344 57 49 41 33 25 17 9 1
345 59 51 43 35 27 19 11 3
346 61 53 45 37 29 21 13 5
347 63 55 47 39 31 23 15 7])
349 (defconst ntlm-smb-perm4 [32 1 2 3 4 5
358 (defconst ntlm-smb-perm5 [16 7 20 21
367 (defconst ntlm-smb-perm6 [40 8 48 16 56 24 64 32
368 39 7 47 15 55 23 63 31
369 38 6 46 14 54 22 62 30
370 37 5 45 13 53 21 61 29
371 36 4 44 12 52 20 60 28
372 35 3 43 11 51 19 59 27
373 34 2 42 10 50 18 58 26
374 33 1 41 9 49 17 57 25])
376 (defconst ntlm-smb-sc [1 1 2 2 2 2 2 2 1 2 2 2 2 2 2 1])
378 (defconst ntlm-smb-sbox [[[14 4 13 1 2 15 11 8 3 10 6 12 5 9 0 7]
379 [ 0 15 7 4 14 2 13 1 10 6 12 11 9 5 3 8]
380 [ 4 1 14 8 13 6 2 11 15 12 9 7 3 10 5 0]
381 [15 12 8 2 4 9 1 7 5 11 3 14 10 0 6 13]]
382 [[15 1 8 14 6 11 3 4 9 7 2 13 12 0 5 10]
383 [ 3 13 4 7 15 2 8 14 12 0 1 10 6 9 11 5]
384 [ 0 14 7 11 10 4 13 1 5 8 12 6 9 3 2 15]
385 [13 8 10 1 3 15 4 2 11 6 7 12 0 5 14 9]]
386 [[10 0 9 14 6 3 15 5 1 13 12 7 11 4 2 8]
387 [13 7 0 9 3 4 6 10 2 8 5 14 12 11 15 1]
388 [13 6 4 9 8 15 3 0 11 1 2 12 5 10 14 7]
389 [ 1 10 13 0 6 9 8 7 4 15 14 3 11 5 2 12]]
390 [[ 7 13 14 3 0 6 9 10 1 2 8 5 11 12 4 15]
391 [13 8 11 5 6 15 0 3 4 7 2 12 1 10 14 9]
392 [10 6 9 0 12 11 7 13 15 1 3 14 5 2 8 4]
393 [ 3 15 0 6 10 1 13 8 9 4 5 11 12 7 2 14]]
394 [[ 2 12 4 1 7 10 11 6 8 5 3 15 13 0 14 9]
395 [14 11 2 12 4 7 13 1 5 0 15 10 3 9 8 6]
396 [ 4 2 1 11 10 13 7 8 15 9 12 5 6 3 0 14]
397 [11 8 12 7 1 14 2 13 6 15 0 9 10 4 5 3]]
398 [[12 1 10 15 9 2 6 8 0 13 3 4 14 7 5 11]
399 [10 15 4 2 7 12 9 5 6 1 13 14 0 11 3 8]
400 [ 9 14 15 5 2 8 12 3 7 0 4 10 1 13 11 6]
401 [ 4 3 2 12 9 5 15 10 11 14 1 7 6 0 8 13]]
402 [[ 4 11 2 14 15 0 8 13 3 12 9 7 5 10 6 1]
403 [13 0 11 7 4 9 1 10 14 3 5 12 2 15 8 6]
404 [ 1 4 11 13 12 3 7 14 10 15 6 8 0 5 9 2]
405 [ 6 11 13 8 1 4 10 7 9 5 0 15 14 2 3 12]]
406 [[13 2 8 4 6 15 11 1 10 9 3 14 5 0 12 7]
407 [ 1 15 13 8 10 3 7 4 12 5 6 11 0 14 9 2]
408 [ 7 11 4 1 9 12 14 2 0 6 10 13 15 3 5 8]
409 [ 2 1 14 7 4 10 8 13 15 12 9 0 3 5 6 11]]])
411 (defsubst ntlm-string-permute (in perm n)
412 "Return a string of length N for a string IN and a permutation vector
413 PERM of size N. The length of IN should be height of PERM."
414 (let ((i 0) (out (make-string n 0)))
416 (aset out i (aref in (- (aref perm i) 1)))
420 (defsubst ntlm-string-lshift (str count len)
421 "Return a string by circularly shifting a string STR by COUNT to the left.
422 length of STR is LEN."
423 (let ((c (% count len)))
424 (concat (substring str c len) (substring str 0 c))))
426 (defsubst ntlm-string-xor (in1 in2 n)
427 "Return exclusive-or of sequences in1 and in2"
428 (let ((w (make-string n 0)) (i 0))
430 (aset w i (logxor (aref in1 i) (aref in2 i)))
434 (defun ntlm-smb-dohash (in key forw)
435 "Return the hash value for a string IN and a string KEY.
436 Length of IN and KEY are 64. FORW non nill means forward, nil means
438 (let (pk1 ;string of length 56
439 c ;string of length 28
440 d ;string of length 28
441 cd ;string of length 56
442 (ki (make-vector 16 0)) ;vector of string of length 48
443 pd1 ;string of length 64
444 l ;string of length 32
445 r ;string of length 32
446 rl ;string of length 64
448 (setq pk1 (ntlm-string-permute key ntlm-smb-perm1 56))
449 (setq c (substring pk1 0 28))
450 (setq d (substring pk1 28 56))
454 (setq c (ntlm-string-lshift c (aref ntlm-smb-sc i) 28))
455 (setq d (ntlm-string-lshift d (aref ntlm-smb-sc i) 28))
456 (setq cd (concat (substring c 0 28) (substring d 0 28)))
457 (aset ki i (ntlm-string-permute cd ntlm-smb-perm2 48))
460 (setq pd1 (ntlm-string-permute in ntlm-smb-perm3 64))
462 (setq l (substring pd1 0 32))
463 (setq r (substring pd1 32 64))
466 (let (er ;string of length 48
467 erk ;string of length 48
468 (b (make-vector 8 0)) ;vector of strings of length 6
469 cb ;string of length 32
470 pcb ;string of length 32
471 r2 ;string of length 32
474 (setq er (ntlm-string-permute r ntlm-smb-perm4 48))
475 (setq erk (ntlm-string-xor er
476 (aref ki (if forw i (- 15 i)))
481 (aset b j (substring erk jj (+ jj 6)))
486 (setq m (logior (lsh (aref bj 0) 1) (aref bj 5)))
487 (setq n (logior (lsh (aref bj 1) 3)
492 (setq sbox-jmn (aref (aref (aref ntlm-smb-sbox j) m) n))
495 (if (zerop (logand sbox-jmn (lsh 1 (- 3 k))))
503 (setq cb (concat cb (substring (aref b j) 0 4)))
506 (setq pcb (ntlm-string-permute cb ntlm-smb-perm5 32))
507 (setq r2 (ntlm-string-xor l pcb 32))
511 (setq rl (concat r l))
512 (ntlm-string-permute rl ntlm-smb-perm6 64)))
514 (defun ntlm-md4hash (passwd)
515 "Return the 16 bytes MD4 hash of a string PASSWD after converting it
516 into a Unicode string. PASSWD is truncated to 128 bytes if longer."
518 ;; Password cannot be longer than 128 characters
519 (setq len (length passwd))
522 ;; Password must be converted to NT unicode
523 (setq wpwd (ntlm-ascii2unicode passwd len))
524 ;; Calculate length in bytes
530 ;;; ntlm.el ends here