1/*-
2 * Copyright (c) 2000-2001, Boris Popov
3 * All rights reserved.
4 *
5 * Copyright (c) 2003, 2004 Tim J. Robbins.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *    This product includes software developed by Boris Popov.
19 * 4. Neither the name of the author nor the names of any co-contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <sys/cdefs.h>
37__FBSDID("$FreeBSD$");
38
39#include <sys/param.h>
40#include <sys/malloc.h>
41#include <sys/kernel.h>
42#include <sys/systm.h>
43#include <sys/conf.h>
44#include <sys/proc.h>
45#include <sys/fcntl.h>
46#include <sys/socket.h>
47#include <sys/socketvar.h>
48#include <sys/sysctl.h>
49#include <sys/endian.h>
50#include <sys/mbuf.h>
51#include <sys/mchain.h>
52#include <sys/md4.h>
53#include <sys/md5.h>
54#include <sys/iconv.h>
55
56#include <netsmb/smb.h>
57#include <netsmb/smb_conn.h>
58#include <netsmb/smb_subr.h>
59#include <netsmb/smb_rq.h>
60#include <netsmb/smb_dev.h>
61
62#include <crypto/des/des.h>
63
64#include "opt_netsmb.h"
65
66static u_char N8[] = {0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25};
67
68
69static void
70smb_E(const u_char *key, u_char *data, u_char *dest)
71{
72	des_key_schedule *ksp;
73	u_char kk[8];
74
75	kk[0] = key[0] & 0xfe;
76	kk[1] = key[0] << 7 | (key[1] >> 1 & 0xfe);
77	kk[2] = key[1] << 6 | (key[2] >> 2 & 0xfe);
78	kk[3] = key[2] << 5 | (key[3] >> 3 & 0xfe);
79	kk[4] = key[3] << 4 | (key[4] >> 4 & 0xfe);
80	kk[5] = key[4] << 3 | (key[5] >> 5 & 0xfe);
81	kk[6] = key[5] << 2 | (key[6] >> 6 & 0xfe);
82	kk[7] = key[6] << 1;
83	ksp = malloc(sizeof(des_key_schedule), M_SMBTEMP, M_WAITOK);
84	des_set_key((des_cblock *)kk, *ksp);
85	des_ecb_encrypt((des_cblock *)data, (des_cblock *)dest, *ksp, 1);
86	free(ksp, M_SMBTEMP);
87}
88
89
90int
91smb_encrypt(const u_char *apwd, u_char *C8, u_char *RN)
92{
93	u_char *p, *P14, *S21;
94
95	p = malloc(14 + 21, M_SMBTEMP, M_WAITOK);
96	bzero(p, 14 + 21);
97	P14 = p;
98	S21 = p + 14;
99	bcopy(apwd, P14, min(14, strlen(apwd)));
100	/*
101	 * S21 = concat(Ex(P14, N8), zeros(5));
102	 */
103	smb_E(P14, N8, S21);
104	smb_E(P14 + 7, N8, S21 + 8);
105
106	smb_E(S21, C8, RN);
107	smb_E(S21 + 7, C8, RN + 8);
108	smb_E(S21 + 14, C8, RN + 16);
109	free(p, M_SMBTEMP);
110	return 0;
111}
112
113int
114smb_ntencrypt(const u_char *apwd, u_char *C8, u_char *RN)
115{
116	u_char S21[21];
117	u_int16_t *unipwd;
118	MD4_CTX *ctxp;
119	int len;
120
121	len = strlen(apwd);
122	unipwd = malloc((len + 1) * sizeof(u_int16_t), M_SMBTEMP, M_WAITOK);
123	/*
124	 * S21 = concat(MD4(U(apwd)), zeros(5));
125	 */
126	smb_strtouni(unipwd, apwd);
127	ctxp = malloc(sizeof(MD4_CTX), M_SMBTEMP, M_WAITOK);
128	MD4Init(ctxp);
129	MD4Update(ctxp, (u_char*)unipwd, len * sizeof(u_int16_t));
130	free(unipwd, M_SMBTEMP);
131	bzero(S21, 21);
132	MD4Final(S21, ctxp);
133	free(ctxp, M_SMBTEMP);
134
135	smb_E(S21, C8, RN);
136	smb_E(S21 + 7, C8, RN + 8);
137	smb_E(S21 + 14, C8, RN + 16);
138	return 0;
139}
140
141/*
142 * Calculate message authentication code (MAC) key for virtual circuit.
143 */
144int
145smb_calcmackey(struct smb_vc *vcp)
146{
147	const char *pwd;
148	u_int16_t *unipwd;
149	int len;
150	MD4_CTX md4;
151	u_char S16[16], S21[21];
152
153	KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
154	    ("signatures not enabled"));
155
156	if (vcp->vc_mackey != NULL) {
157		free(vcp->vc_mackey, M_SMBTEMP);
158		vcp->vc_mackey = NULL;
159		vcp->vc_mackeylen = 0;
160		vcp->vc_seqno = 0;
161	}
162
163	/*
164	 * The partial MAC key is the concatenation of the 16 byte session
165	 * key and the 24 byte challenge response.
166	 */
167	vcp->vc_mackeylen = 16 + 24;
168	vcp->vc_mackey = malloc(vcp->vc_mackeylen, M_SMBTEMP, M_WAITOK);
169
170	/*
171	 * Calculate session key:
172	 *	MD4(MD4(U(PN)))
173	 */
174	pwd = smb_vc_getpass(vcp);
175	len = strlen(pwd);
176	unipwd = malloc((len + 1) * sizeof(u_int16_t), M_SMBTEMP, M_WAITOK);
177	smb_strtouni(unipwd, pwd);
178	MD4Init(&md4);
179	MD4Update(&md4, (u_char *)unipwd, len * sizeof(u_int16_t));
180	MD4Final(S16, &md4);
181	MD4Init(&md4);
182	MD4Update(&md4, S16, 16);
183	MD4Final(vcp->vc_mackey, &md4);
184	free(unipwd, M_SMBTEMP);
185
186	/*
187	 * Calculate response to challenge:
188	 *	Ex(concat(MD4(U(pass)), zeros(5)), C8)
189	 */
190	bzero(S21, 21);
191	bcopy(S16, S21, 16);
192	smb_E(S21, vcp->vc_ch, vcp->vc_mackey + 16);
193	smb_E(S21 + 7, vcp->vc_ch, vcp->vc_mackey + 24);
194	smb_E(S21 + 14, vcp->vc_ch, vcp->vc_mackey + 32);
195
196	return (0);
197}
198
199/*
200 * Sign request with MAC.
201 */
202int
203smb_rq_sign(struct smb_rq *rqp)
204{
205	struct smb_vc *vcp = rqp->sr_vc;
206	struct mbchain *mbp;
207	struct mbuf *mb;
208	MD5_CTX md5;
209	u_char digest[16];
210
211	KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
212	    ("signatures not enabled"));
213
214	if (vcp->vc_mackey == NULL)
215		/* XXX Should assert that cmd == SMB_COM_NEGOTIATE. */
216		return (0);
217
218	/*
219	 * This is a bit of a kludge. If the request is non-TRANSACTION,
220	 * or it is the first request of a transaction, give it the next
221	 * sequence number, and expect the reply to have the sequence number
222	 * following that one. Otherwise, it is a secondary request in
223	 * a transaction, and it gets the same sequence numbers as the
224	 * primary request.
225	 */
226	if (rqp->sr_t2 == NULL ||
227	    (rqp->sr_t2->t2_flags & SMBT2_SECONDARY) == 0) {
228		rqp->sr_seqno = vcp->vc_seqno++;
229		rqp->sr_rseqno = vcp->vc_seqno++;
230	} else {
231		/*
232		 * Sequence numbers are already in the struct because
233		 * smb_t2_request_int() uses the same one for all the
234		 * requests in the transaction.
235		 * (At least we hope so.)
236		 */
237		KASSERT(rqp->sr_t2 == NULL ||
238		    (rqp->sr_t2->t2_flags & SMBT2_SECONDARY) == 0 ||
239		    rqp->sr_t2->t2_rq == rqp,
240		    ("sec t2 rq not using same smb_rq"));
241	}
242
243	/* Initialize sec. signature field to sequence number + zeros. */
244	le32enc(rqp->sr_rqsig, rqp->sr_seqno);
245	le32enc(rqp->sr_rqsig + 4, 0);
246
247	/*
248	 * Compute HMAC-MD5 of packet data, keyed by MAC key.
249	 * Store the first 8 bytes in the sec. signature field.
250	 */
251	smb_rq_getrequest(rqp, &mbp);
252	MD5Init(&md5);
253	MD5Update(&md5, vcp->vc_mackey, vcp->vc_mackeylen);
254	for (mb = mbp->mb_top; mb != NULL; mb = mb->m_next)
255		MD5Update(&md5, mtod(mb, void *), mb->m_len);
256	MD5Final(digest, &md5);
257	bcopy(digest, rqp->sr_rqsig, 8);
258
259	return (0);
260}
261
262/*
263 * Verify reply signature.
264 */
265int
266smb_rq_verify(struct smb_rq *rqp)
267{
268	struct smb_vc *vcp = rqp->sr_vc;
269	struct mdchain *mdp;
270	u_char sigbuf[8];
271	MD5_CTX md5;
272	u_char digest[16];
273	struct mbuf *mb;
274
275	KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
276	    ("signatures not enabled"));
277
278	if (vcp->vc_mackey == NULL)
279		/* XXX Should check that this is a SMB_COM_NEGOTIATE reply. */
280		return (0);
281
282	/*
283	 * Compute HMAC-MD5 of packet data, keyed by MAC key.
284	 * We play games to pretend the security signature field
285	 * contains their sequence number, to avoid modifying
286	 * the packet itself.
287	 */
288	smb_rq_getreply(rqp, &mdp);
289	mb = mdp->md_top;
290	KASSERT(mb->m_len >= SMB_HDRLEN, ("forgot to m_pullup"));
291	MD5Init(&md5);
292	MD5Update(&md5, vcp->vc_mackey, vcp->vc_mackeylen);
293	MD5Update(&md5, mtod(mb, void *), 14);
294	*(u_int32_t *)sigbuf = htole32(rqp->sr_rseqno);
295	*(u_int32_t *)(sigbuf + 4) = 0;
296	MD5Update(&md5, sigbuf, 8);
297	MD5Update(&md5, mtod(mb, u_char *) + 22, mb->m_len - 22);
298	for (mb = mb->m_next; mb != NULL; mb = mb->m_next)
299		MD5Update(&md5, mtod(mb, void *), mb->m_len);
300	MD5Final(digest, &md5);
301
302	/*
303	 * Now verify the signature.
304	 */
305	if (bcmp(mtod(mdp->md_top, u_char *) + 14, digest, 8) != 0)
306		return (EAUTH);
307
308	return (0);
309}
310