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: src/sys/netsmb/smb_crypt.c,v 1.10 2006/08/22 03:05:51 marcel Exp $");
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
66 static u_char N8[] = {0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25};
67
68
69 static void
70 smb_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
90 int
91 smb_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
113 int
114 smb_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 */
144 int
145 smb_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 */
202 int
203 smb_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 */
265 int
266 smb_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
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