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("$FreeBSD$"); 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 } 340