1 /*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (c) 2000-2001, Boris Popov
5 * All rights reserved.
6 *
7 * Copyright (c) 2003, 2004 Tim J. Robbins.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by Boris Popov.
21 * 4. Neither the name of the author nor the names of any co-contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 */
37
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 #include <sys/param.h>
42 #include <sys/malloc.h>
43 #include <sys/kernel.h>
44 #include <sys/systm.h>
45 #include <sys/conf.h>
46 #include <sys/proc.h>
47 #include <sys/fcntl.h>
48 #include <sys/socket.h>
49 #include <sys/socketvar.h>
50 #include <sys/sysctl.h>
51 #include <sys/endian.h>
52 #include <sys/mbuf.h>
53 #include <sys/mchain.h>
54 #include <sys/md4.h>
55 #include <sys/md5.h>
56 #include <sys/iconv.h>
57
58 #include <netsmb/smb.h>
59 #include <netsmb/smb_conn.h>
60 #include <netsmb/smb_subr.h>
61 #include <netsmb/smb_rq.h>
62 #include <netsmb/smb_dev.h>
63
64 #include <crypto/des/des.h>
65
66 #include "opt_netsmb.h"
67
68 static u_char N8[] = {0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25};
69
70
71 static void
72 smb_E(const u_char *key, u_char *data, u_char *dest)
73 {
74 des_key_schedule *ksp;
75 u_char kk[8];
76
77 kk[0] = key[0] & 0xfe;
78 kk[1] = key[0] << 7 | (key[1] >> 1 & 0xfe);
79 kk[2] = key[1] << 6 | (key[2] >> 2 & 0xfe);
80 kk[3] = key[2] << 5 | (key[3] >> 3 & 0xfe);
81 kk[4] = key[3] << 4 | (key[4] >> 4 & 0xfe);
82 kk[5] = key[4] << 3 | (key[5] >> 5 & 0xfe);
83 kk[6] = key[5] << 2 | (key[6] >> 6 & 0xfe);
84 kk[7] = key[6] << 1;
85 ksp = malloc(sizeof(des_key_schedule), M_SMBTEMP, M_WAITOK);
86 des_set_key((des_cblock *)kk, *ksp);
87 des_ecb_encrypt((des_cblock *)data, (des_cblock *)dest, *ksp, 1);
88 free(ksp, M_SMBTEMP);
89 }
90
91
92 int
93 smb_encrypt(const u_char *apwd, u_char *C8, u_char *RN)
94 {
95 u_char *p, *P14, *S21;
96
97 p = malloc(14 + 21, M_SMBTEMP, M_WAITOK);
98 bzero(p, 14 + 21);
99 P14 = p;
100 S21 = p + 14;
101 bcopy(apwd, P14, min(14, strlen(apwd)));
102 /*
103 * S21 = concat(Ex(P14, N8), zeros(5));
104 */
105 smb_E(P14, N8, S21);
106 smb_E(P14 + 7, N8, S21 + 8);
107
108 smb_E(S21, C8, RN);
109 smb_E(S21 + 7, C8, RN + 8);
110 smb_E(S21 + 14, C8, RN + 16);
111 free(p, M_SMBTEMP);
112 return 0;
113 }
114
115 int
116 smb_ntencrypt(const u_char *apwd, u_char *C8, u_char *RN)
117 {
118 u_char S21[21];
119 u_int16_t *unipwd;
120 MD4_CTX *ctxp;
121 u_int len;
122
123 len = strlen(apwd);
124 unipwd = malloc((len + 1) * sizeof(u_int16_t), M_SMBTEMP, M_WAITOK);
125 /*
126 * S21 = concat(MD4(U(apwd)), zeros(5));
127 */
128 smb_strtouni(unipwd, apwd);
129 ctxp = malloc(sizeof(MD4_CTX), M_SMBTEMP, M_WAITOK);
130 MD4Init(ctxp);
131 MD4Update(ctxp, (u_char*)unipwd, len * sizeof(u_int16_t));
132 free(unipwd, M_SMBTEMP);
133 bzero(S21, 21);
134 MD4Final(S21, ctxp);
135 free(ctxp, M_SMBTEMP);
136
137 smb_E(S21, C8, RN);
138 smb_E(S21 + 7, C8, RN + 8);
139 smb_E(S21 + 14, C8, RN + 16);
140 return 0;
141 }
142
143 /*
144 * Calculate message authentication code (MAC) key for virtual circuit.
145 */
146 int
147 smb_calcmackey(struct smb_vc *vcp)
148 {
149 const char *pwd;
150 u_int16_t *unipwd;
151 u_int len;
152 MD4_CTX md4;
153 u_char S16[16], S21[21];
154
155 KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
156 ("signatures not enabled"));
157
158 if (vcp->vc_mackey != NULL) {
159 free(vcp->vc_mackey, M_SMBTEMP);
160 vcp->vc_mackey = NULL;
161 vcp->vc_mackeylen = 0;
162 vcp->vc_seqno = 0;
163 }
164
165 /*
166 * The partial MAC key is the concatenation of the 16 byte session
167 * key and the 24 byte challenge response.
168 */
169 vcp->vc_mackeylen = 16 + 24;
170 vcp->vc_mackey = malloc(vcp->vc_mackeylen, M_SMBTEMP, M_WAITOK);
171
172 /*
173 * Calculate session key:
174 * MD4(MD4(U(PN)))
175 */
176 pwd = smb_vc_getpass(vcp);
177 len = strlen(pwd);
178 unipwd = malloc((len + 1) * sizeof(u_int16_t), M_SMBTEMP, M_WAITOK);
179 smb_strtouni(unipwd, pwd);
180 MD4Init(&md4);
181 MD4Update(&md4, (u_char *)unipwd, len * sizeof(u_int16_t));
182 MD4Final(S16, &md4);
183 MD4Init(&md4);
184 MD4Update(&md4, S16, 16);
185 MD4Final(vcp->vc_mackey, &md4);
186 free(unipwd, M_SMBTEMP);
187
188 /*
189 * Calculate response to challenge:
190 * Ex(concat(MD4(U(pass)), zeros(5)), C8)
191 */
192 bzero(S21, 21);
193 bcopy(S16, S21, 16);
194 smb_E(S21, vcp->vc_ch, vcp->vc_mackey + 16);
195 smb_E(S21 + 7, vcp->vc_ch, vcp->vc_mackey + 24);
196 smb_E(S21 + 14, vcp->vc_ch, vcp->vc_mackey + 32);
197
198 return (0);
199 }
200
201 /*
202 * Sign request with MAC.
203 */
204 int
205 smb_rq_sign(struct smb_rq *rqp)
206 {
207 struct smb_vc *vcp = rqp->sr_vc;
208 struct mbchain *mbp;
209 struct mbuf *mb;
210 MD5_CTX md5;
211 u_char digest[16];
212
213 KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
214 ("signatures not enabled"));
215
216 if (vcp->vc_mackey == NULL)
217 /* XXX Should assert that cmd == SMB_COM_NEGOTIATE. */
218 return (0);
219
220 /*
221 * This is a bit of a kludge. If the request is non-TRANSACTION,
222 * or it is the first request of a transaction, give it the next
223 * sequence number, and expect the reply to have the sequence number
224 * following that one. Otherwise, it is a secondary request in
225 * a transaction, and it gets the same sequence numbers as the
226 * primary request.
227 */
228 if (rqp->sr_t2 == NULL ||
229 (rqp->sr_t2->t2_flags & SMBT2_SECONDARY) == 0) {
230 rqp->sr_seqno = vcp->vc_seqno++;
231 rqp->sr_rseqno = vcp->vc_seqno++;
232 } else {
233 /*
234 * Sequence numbers are already in the struct because
235 * smb_t2_request_int() uses the same one for all the
236 * requests in the transaction.
237 * (At least we hope so.)
238 */
239 KASSERT(rqp->sr_t2 == NULL ||
240 (rqp->sr_t2->t2_flags & SMBT2_SECONDARY) == 0 ||
241 rqp->sr_t2->t2_rq == rqp,
242 ("sec t2 rq not using same smb_rq"));
243 }
244
245 /* Initialize sec. signature field to sequence number + zeros. */
246 le32enc(rqp->sr_rqsig, rqp->sr_seqno);
247 le32enc(rqp->sr_rqsig + 4, 0);
248
249 /*
250 * Compute HMAC-MD5 of packet data, keyed by MAC key.
251 * Store the first 8 bytes in the sec. signature field.
252 */
253 smb_rq_getrequest(rqp, &mbp);
254 MD5Init(&md5);
255 MD5Update(&md5, vcp->vc_mackey, vcp->vc_mackeylen);
256 for (mb = mbp->mb_top; mb != NULL; mb = mb->m_next)
257 MD5Update(&md5, mtod(mb, void *), mb->m_len);
258 MD5Final(digest, &md5);
259 bcopy(digest, rqp->sr_rqsig, 8);
260
261 return (0);
262 }
263
264 /*
265 * Verify reply signature.
266 */
267 int
268 smb_rq_verify(struct smb_rq *rqp)
269 {
270 struct smb_vc *vcp = rqp->sr_vc;
271 struct mdchain *mdp;
272 u_char sigbuf[8];
273 MD5_CTX md5;
274 u_char digest[16];
275 struct mbuf *mb;
276
277 KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
278 ("signatures not enabled"));
279
280 if (vcp->vc_mackey == NULL)
281 /* XXX Should check that this is a SMB_COM_NEGOTIATE reply. */
282 return (0);
283
284 /*
285 * Compute HMAC-MD5 of packet data, keyed by MAC key.
286 * We play games to pretend the security signature field
287 * contains their sequence number, to avoid modifying
288 * the packet itself.
289 */
290 smb_rq_getreply(rqp, &mdp);
291 mb = mdp->md_top;
292 KASSERT(mb->m_len >= SMB_HDRLEN, ("forgot to m_pullup"));
293 MD5Init(&md5);
294 MD5Update(&md5, vcp->vc_mackey, vcp->vc_mackeylen);
295 MD5Update(&md5, mtod(mb, void *), 14);
296 *(u_int32_t *)sigbuf = htole32(rqp->sr_rseqno);
297 *(u_int32_t *)(sigbuf + 4) = 0;
298 MD5Update(&md5, sigbuf, 8);
299 MD5Update(&md5, mtod(mb, u_char *) + 22, mb->m_len - 22);
300 for (mb = mb->m_next; mb != NULL; mb = mb->m_next)
301 MD5Update(&md5, mtod(mb, void *), mb->m_len);
302 MD5Final(digest, &md5);
303
304 /*
305 * Now verify the signature.
306 */
307 if (bcmp(mtod(mdp->md_top, u_char *) + 14, digest, 8) != 0)
308 return (EAUTH);
309
310 return (0);
311 }
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