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(kk, *ksp); 87 des_ecb_encrypt(data, 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 } 312