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 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 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 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 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 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 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