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 <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