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: releng/5.3/sys/netsmb/smb_crypt.c 124087 2004-01-02 22:38:42Z tjr $");
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 "opt_netsmb.h"
63
64 #ifdef NETSMBCRYPTO
65
66 #include <crypto/des/des.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 #endif
91
92
93 int
94 smb_encrypt(const u_char *apwd, u_char *C8, u_char *RN)
95 {
96 #ifdef NETSMBCRYPTO
97 u_char *p, *P14, *S21;
98
99 p = malloc(14 + 21, M_SMBTEMP, M_WAITOK);
100 bzero(p, 14 + 21);
101 P14 = p;
102 S21 = p + 14;
103 bcopy(apwd, P14, min(14, strlen(apwd)));
104 /*
105 * S21 = concat(Ex(P14, N8), zeros(5));
106 */
107 smb_E(P14, N8, S21);
108 smb_E(P14 + 7, N8, S21 + 8);
109
110 smb_E(S21, C8, RN);
111 smb_E(S21 + 7, C8, RN + 8);
112 smb_E(S21 + 14, C8, RN + 16);
113 free(p, M_SMBTEMP);
114 return 0;
115 #else
116 SMBERROR("password encryption is not available\n");
117 bzero(RN, 24);
118 return EAUTH;
119 #endif
120 }
121
122 int
123 smb_ntencrypt(const u_char *apwd, u_char *C8, u_char *RN)
124 {
125 #ifdef NETSMBCRYPTO
126 u_char S21[21];
127 u_int16_t *unipwd;
128 MD4_CTX *ctxp;
129 int len;
130
131 len = strlen(apwd);
132 unipwd = malloc((len + 1) * sizeof(u_int16_t), M_SMBTEMP, M_WAITOK);
133 /*
134 * S21 = concat(MD4(U(apwd)), zeros(5));
135 */
136 smb_strtouni(unipwd, apwd);
137 ctxp = malloc(sizeof(MD4_CTX), M_SMBTEMP, M_WAITOK);
138 MD4Init(ctxp);
139 MD4Update(ctxp, (u_char*)unipwd, len * sizeof(u_int16_t));
140 free(unipwd, M_SMBTEMP);
141 bzero(S21, 21);
142 MD4Final(S21, ctxp);
143 free(ctxp, M_SMBTEMP);
144
145 smb_E(S21, C8, RN);
146 smb_E(S21 + 7, C8, RN + 8);
147 smb_E(S21 + 14, C8, RN + 16);
148 return 0;
149 #else
150 SMBERROR("password encryption is not available\n");
151 bzero(RN, 24);
152 return EAUTH;
153 #endif
154 }
155
156 /*
157 * Calculate message authentication code (MAC) key for virtual circuit.
158 */
159 int
160 smb_calcmackey(struct smb_vc *vcp)
161 {
162 #ifdef NETSMBCRYPTO
163 const char *pwd;
164 u_int16_t *unipwd;
165 int len;
166 MD4_CTX md4;
167 u_char S16[16], S21[21];
168
169 KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
170 ("signatures not enabled"));
171
172 if (vcp->vc_mackey != NULL) {
173 free(vcp->vc_mackey, M_SMBTEMP);
174 vcp->vc_mackey = NULL;
175 vcp->vc_mackeylen = 0;
176 vcp->vc_seqno = 0;
177 }
178
179 /*
180 * The partial MAC key is the concatenation of the 16 byte session
181 * key and the 24 byte challenge response.
182 */
183 vcp->vc_mackeylen = 16 + 24;
184 vcp->vc_mackey = malloc(vcp->vc_mackeylen, M_SMBTEMP, M_WAITOK);
185
186 /*
187 * Calculate session key:
188 * MD4(MD4(U(PN)))
189 */
190 pwd = smb_vc_getpass(vcp);
191 len = strlen(pwd);
192 unipwd = malloc((len + 1) * sizeof(u_int16_t), M_SMBTEMP, M_WAITOK);
193 smb_strtouni(unipwd, pwd);
194 MD4Init(&md4);
195 MD4Update(&md4, (u_char *)unipwd, len * sizeof(u_int16_t));
196 MD4Final(S16, &md4);
197 MD4Init(&md4);
198 MD4Update(&md4, S16, 16);
199 MD4Final(vcp->vc_mackey, &md4);
200 free(unipwd, M_SMBTEMP);
201
202 /*
203 * Calculate response to challenge:
204 * Ex(concat(MD4(U(pass)), zeros(5)), C8)
205 */
206 bzero(S21, 21);
207 bcopy(S16, S21, 16);
208 smb_E(S21, vcp->vc_ch, vcp->vc_mackey + 16);
209 smb_E(S21 + 7, vcp->vc_ch, vcp->vc_mackey + 24);
210 smb_E(S21 + 14, vcp->vc_ch, vcp->vc_mackey + 32);
211
212 return (0);
213 #else
214 panic("smb_calcmackey: encryption not available");
215 return (0);
216 #endif /* NETSMBCRYPTO */
217 }
218
219 /*
220 * Sign request with MAC.
221 */
222 int
223 smb_rq_sign(struct smb_rq *rqp)
224 {
225 #ifdef NETSMBCRYPTO
226 struct smb_vc *vcp = rqp->sr_vc;
227 struct mbchain *mbp;
228 struct mbuf *mb;
229 MD5_CTX md5;
230 u_char digest[16];
231
232 KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
233 ("signatures not enabled"));
234
235 if (vcp->vc_mackey == NULL)
236 /* XXX Should assert that cmd == SMB_COM_NEGOTIATE. */
237 return (0);
238
239 /*
240 * This is a bit of a kludge. If the request is non-TRANSACTION,
241 * or it is the first request of a transaction, give it the next
242 * sequence number, and expect the reply to have the sequence number
243 * following that one. Otherwise, it is a secondary request in
244 * a transaction, and it gets the same sequence numbers as the
245 * primary request.
246 */
247 if (rqp->sr_t2 == NULL ||
248 (rqp->sr_t2->t2_flags & SMBT2_SECONDARY) == 0) {
249 rqp->sr_seqno = vcp->vc_seqno++;
250 rqp->sr_rseqno = vcp->vc_seqno++;
251 } else {
252 /*
253 * Sequence numbers are already in the struct because
254 * smb_t2_request_int() uses the same one for all the
255 * requests in the transaction.
256 * (At least we hope so.)
257 */
258 KASSERT(rqp->sr_t2 == NULL ||
259 (rqp->sr_t2->t2_flags & SMBT2_SECONDARY) == 0 ||
260 rqp->sr_t2->t2_rq == rqp,
261 ("sec t2 rq not using same smb_rq"));
262 }
263
264 /* Initialize sec. signature field to sequence number + zeros. */
265 *(u_int32_t *)rqp->sr_rqsig = htole32(rqp->sr_seqno);
266 *(u_int32_t *)(rqp->sr_rqsig + 4) = 0;
267
268 /*
269 * Compute HMAC-MD5 of packet data, keyed by MAC key.
270 * Store the first 8 bytes in the sec. signature field.
271 */
272 smb_rq_getrequest(rqp, &mbp);
273 MD5Init(&md5);
274 MD5Update(&md5, vcp->vc_mackey, vcp->vc_mackeylen);
275 for (mb = mbp->mb_top; mb != NULL; mb = mb->m_next)
276 MD5Update(&md5, mtod(mb, void *), mb->m_len);
277 MD5Final(digest, &md5);
278 bcopy(digest, rqp->sr_rqsig, 8);
279
280 return (0);
281 #else
282 panic("smb_rq_sign: encryption not available");
283 return (0);
284 #endif /* NETSMBCRYPTO */
285 }
286
287 /*
288 * Verify reply signature.
289 */
290 int
291 smb_rq_verify(struct smb_rq *rqp)
292 {
293 #ifdef NETSMBCRYPTO
294 struct smb_vc *vcp = rqp->sr_vc;
295 struct mdchain *mdp;
296 u_char sigbuf[8];
297 MD5_CTX md5;
298 u_char digest[16];
299 struct mbuf *mb;
300
301 KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
302 ("signatures not enabled"));
303
304 if (vcp->vc_mackey == NULL)
305 /* XXX Should check that this is a SMB_COM_NEGOTIATE reply. */
306 return (0);
307
308 /*
309 * Compute HMAC-MD5 of packet data, keyed by MAC key.
310 * We play games to pretend the security signature field
311 * contains their sequence number, to avoid modifying
312 * the packet itself.
313 */
314 smb_rq_getreply(rqp, &mdp);
315 mb = mdp->md_top;
316 KASSERT(mb->m_len >= SMB_HDRLEN, ("forgot to m_pullup"));
317 MD5Init(&md5);
318 MD5Update(&md5, vcp->vc_mackey, vcp->vc_mackeylen);
319 MD5Update(&md5, mtod(mb, void *), 14);
320 *(u_int32_t *)sigbuf = htole32(rqp->sr_rseqno);
321 *(u_int32_t *)(sigbuf + 4) = 0;
322 MD5Update(&md5, sigbuf, 8);
323 MD5Update(&md5, mtod(mb, u_char *) + 22, mb->m_len - 22);
324 for (mb = mb->m_next; mb != NULL; mb = mb->m_next)
325 MD5Update(&md5, mtod(mb, void *), mb->m_len);
326 MD5Final(digest, &md5);
327
328 /*
329 * Now verify the signature.
330 */
331 if (bcmp(mtod(mdp->md_top, u_char *) + 14, digest, 8) != 0)
332 return (EAUTH);
333
334 return (0);
335 #else
336 panic("smb_rq_verify: encryption not available");
337 return (0);
338 #endif /* NETSMBCRYPTO */
339 }
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