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/param.h>
39 #include <sys/malloc.h>
40 #include <sys/kernel.h>
41 #include <sys/systm.h>
42 #include <sys/conf.h>
43 #include <sys/proc.h>
44 #include <sys/fcntl.h>
45 #include <sys/socket.h>
46 #include <sys/socketvar.h>
47 #include <sys/sysctl.h>
48 #include <sys/endian.h>
49 #include <sys/mbuf.h>
50 #include <sys/mchain.h>
51 #include <sys/md4.h>
52 #include <sys/md5.h>
53 #include <sys/iconv.h>
54
55 #include <netsmb/smb.h>
56 #include <netsmb/smb_conn.h>
57 #include <netsmb/smb_subr.h>
58 #include <netsmb/smb_rq.h>
59 #include <netsmb/smb_dev.h>
60
61 #include <crypto/des/des.h>
62
63 #include "opt_netsmb.h"
64
65 static u_char N8[] = {0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25};
66
67 static void
smb_E(const u_char * key,u_char * data,u_char * dest)68 smb_E(const u_char *key, u_char *data, u_char *dest)
69 {
70 des_key_schedule *ksp;
71 u_char kk[8];
72
73 kk[0] = key[0] & 0xfe;
74 kk[1] = key[0] << 7 | (key[1] >> 1 & 0xfe);
75 kk[2] = key[1] << 6 | (key[2] >> 2 & 0xfe);
76 kk[3] = key[2] << 5 | (key[3] >> 3 & 0xfe);
77 kk[4] = key[3] << 4 | (key[4] >> 4 & 0xfe);
78 kk[5] = key[4] << 3 | (key[5] >> 5 & 0xfe);
79 kk[6] = key[5] << 2 | (key[6] >> 6 & 0xfe);
80 kk[7] = key[6] << 1;
81 ksp = malloc(sizeof(des_key_schedule), M_SMBTEMP, M_WAITOK);
82 des_set_key(kk, *ksp);
83 des_ecb_encrypt(data, dest, *ksp, 1);
84 free(ksp, M_SMBTEMP);
85 }
86
87 int
smb_encrypt(const u_char * apwd,u_char * C8,u_char * RN)88 smb_encrypt(const u_char *apwd, u_char *C8, u_char *RN)
89 {
90 u_char *p, *P14, *S21;
91
92 p = malloc(14 + 21, M_SMBTEMP, M_WAITOK);
93 bzero(p, 14 + 21);
94 P14 = p;
95 S21 = p + 14;
96 bcopy(apwd, P14, min(14, strlen(apwd)));
97 /*
98 * S21 = concat(Ex(P14, N8), zeros(5));
99 */
100 smb_E(P14, N8, S21);
101 smb_E(P14 + 7, N8, S21 + 8);
102
103 smb_E(S21, C8, RN);
104 smb_E(S21 + 7, C8, RN + 8);
105 smb_E(S21 + 14, C8, RN + 16);
106 free(p, M_SMBTEMP);
107 return 0;
108 }
109
110 int
smb_ntencrypt(const u_char * apwd,u_char * C8,u_char * RN)111 smb_ntencrypt(const u_char *apwd, u_char *C8, u_char *RN)
112 {
113 u_char S21[21];
114 u_int16_t *unipwd;
115 MD4_CTX *ctxp;
116 u_int len;
117
118 len = strlen(apwd);
119 unipwd = malloc((len + 1) * sizeof(u_int16_t), M_SMBTEMP, M_WAITOK);
120 /*
121 * S21 = concat(MD4(U(apwd)), zeros(5));
122 */
123 smb_strtouni(unipwd, apwd);
124 ctxp = malloc(sizeof(MD4_CTX), M_SMBTEMP, M_WAITOK);
125 MD4Init(ctxp);
126 MD4Update(ctxp, (u_char*)unipwd, len * sizeof(u_int16_t));
127 free(unipwd, M_SMBTEMP);
128 bzero(S21, 21);
129 MD4Final(S21, ctxp);
130 free(ctxp, M_SMBTEMP);
131
132 smb_E(S21, C8, RN);
133 smb_E(S21 + 7, C8, RN + 8);
134 smb_E(S21 + 14, C8, RN + 16);
135 return 0;
136 }
137
138 /*
139 * Calculate message authentication code (MAC) key for virtual circuit.
140 */
141 int
smb_calcmackey(struct smb_vc * vcp)142 smb_calcmackey(struct smb_vc *vcp)
143 {
144 const char *pwd;
145 u_int16_t *unipwd;
146 u_int len;
147 MD4_CTX md4;
148 u_char S16[16], S21[21];
149
150 KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
151 ("signatures not enabled"));
152
153 if (vcp->vc_mackey != NULL) {
154 free(vcp->vc_mackey, M_SMBTEMP);
155 vcp->vc_mackey = NULL;
156 vcp->vc_mackeylen = 0;
157 vcp->vc_seqno = 0;
158 }
159
160 /*
161 * The partial MAC key is the concatenation of the 16 byte session
162 * key and the 24 byte challenge response.
163 */
164 vcp->vc_mackeylen = 16 + 24;
165 vcp->vc_mackey = malloc(vcp->vc_mackeylen, M_SMBTEMP, M_WAITOK);
166
167 /*
168 * Calculate session key:
169 * MD4(MD4(U(PN)))
170 */
171 pwd = smb_vc_getpass(vcp);
172 len = strlen(pwd);
173 unipwd = malloc((len + 1) * sizeof(u_int16_t), M_SMBTEMP, M_WAITOK);
174 smb_strtouni(unipwd, pwd);
175 MD4Init(&md4);
176 MD4Update(&md4, (u_char *)unipwd, len * sizeof(u_int16_t));
177 MD4Final(S16, &md4);
178 MD4Init(&md4);
179 MD4Update(&md4, S16, 16);
180 MD4Final(vcp->vc_mackey, &md4);
181 free(unipwd, M_SMBTEMP);
182
183 /*
184 * Calculate response to challenge:
185 * Ex(concat(MD4(U(pass)), zeros(5)), C8)
186 */
187 bzero(S21, 21);
188 bcopy(S16, S21, 16);
189 smb_E(S21, vcp->vc_ch, vcp->vc_mackey + 16);
190 smb_E(S21 + 7, vcp->vc_ch, vcp->vc_mackey + 24);
191 smb_E(S21 + 14, vcp->vc_ch, vcp->vc_mackey + 32);
192
193 return (0);
194 }
195
196 /*
197 * Sign request with MAC.
198 */
199 int
smb_rq_sign(struct smb_rq * rqp)200 smb_rq_sign(struct smb_rq *rqp)
201 {
202 struct smb_vc *vcp = rqp->sr_vc;
203 struct mbchain *mbp;
204 struct mbuf *mb;
205 MD5_CTX md5;
206 u_char digest[16];
207
208 KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
209 ("signatures not enabled"));
210
211 if (vcp->vc_mackey == NULL)
212 /* XXX Should assert that cmd == SMB_COM_NEGOTIATE. */
213 return (0);
214
215 /*
216 * This is a bit of a kludge. If the request is non-TRANSACTION,
217 * or it is the first request of a transaction, give it the next
218 * sequence number, and expect the reply to have the sequence number
219 * following that one. Otherwise, it is a secondary request in
220 * a transaction, and it gets the same sequence numbers as the
221 * primary request.
222 */
223 if (rqp->sr_t2 == NULL ||
224 (rqp->sr_t2->t2_flags & SMBT2_SECONDARY) == 0) {
225 rqp->sr_seqno = vcp->vc_seqno++;
226 rqp->sr_rseqno = vcp->vc_seqno++;
227 } else {
228 /*
229 * Sequence numbers are already in the struct because
230 * smb_t2_request_int() uses the same one for all the
231 * requests in the transaction.
232 * (At least we hope so.)
233 */
234 KASSERT(rqp->sr_t2 == NULL ||
235 (rqp->sr_t2->t2_flags & SMBT2_SECONDARY) == 0 ||
236 rqp->sr_t2->t2_rq == rqp,
237 ("sec t2 rq not using same smb_rq"));
238 }
239
240 /* Initialize sec. signature field to sequence number + zeros. */
241 le32enc(rqp->sr_rqsig, rqp->sr_seqno);
242 le32enc(rqp->sr_rqsig + 4, 0);
243
244 /*
245 * Compute HMAC-MD5 of packet data, keyed by MAC key.
246 * Store the first 8 bytes in the sec. signature field.
247 */
248 smb_rq_getrequest(rqp, &mbp);
249 MD5Init(&md5);
250 MD5Update(&md5, vcp->vc_mackey, vcp->vc_mackeylen);
251 for (mb = mbp->mb_top; mb != NULL; mb = mb->m_next)
252 MD5Update(&md5, mtod(mb, void *), mb->m_len);
253 MD5Final(digest, &md5);
254 bcopy(digest, rqp->sr_rqsig, 8);
255
256 return (0);
257 }
258
259 /*
260 * Verify reply signature.
261 */
262 int
smb_rq_verify(struct smb_rq * rqp)263 smb_rq_verify(struct smb_rq *rqp)
264 {
265 struct smb_vc *vcp = rqp->sr_vc;
266 struct mdchain *mdp;
267 u_char sigbuf[8];
268 MD5_CTX md5;
269 u_char digest[16];
270 struct mbuf *mb;
271
272 KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
273 ("signatures not enabled"));
274
275 if (vcp->vc_mackey == NULL)
276 /* XXX Should check that this is a SMB_COM_NEGOTIATE reply. */
277 return (0);
278
279 /*
280 * Compute HMAC-MD5 of packet data, keyed by MAC key.
281 * We play games to pretend the security signature field
282 * contains their sequence number, to avoid modifying
283 * the packet itself.
284 */
285 smb_rq_getreply(rqp, &mdp);
286 mb = mdp->md_top;
287 KASSERT(mb->m_len >= SMB_HDRLEN, ("forgot to m_pullup"));
288 MD5Init(&md5);
289 MD5Update(&md5, vcp->vc_mackey, vcp->vc_mackeylen);
290 MD5Update(&md5, mtod(mb, void *), 14);
291 *(u_int32_t *)sigbuf = htole32(rqp->sr_rseqno);
292 *(u_int32_t *)(sigbuf + 4) = 0;
293 MD5Update(&md5, sigbuf, 8);
294 MD5Update(&md5, mtod(mb, u_char *) + 22, mb->m_len - 22);
295 for (mb = mb->m_next; mb != NULL; mb = mb->m_next)
296 MD5Update(&md5, mtod(mb, void *), mb->m_len);
297 MD5Final(digest, &md5);
298
299 /*
300 * Now verify the signature.
301 */
302 if (bcmp(mtod(mdp->md_top, u_char *) + 14, digest, 8) != 0)
303 return (EAUTH);
304
305 return (0);
306 }
307