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 * $FreeBSD: src/sys/netsmb/smb_crypt.c,v 1.1.2.3 2001/09/03 08:55:11 bp Exp $ 36 * $DragonFly: src/sys/netproto/smb/smb_crypt.c,v 1.5 2008/01/05 14:02:40 swildner Exp $ 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 49 #include <sys/endian.h> 50 #include <sys/mbuf.h> 51 #include <sys/mchain.h> 52 53 #include <sys/md4.h> 54 #include <sys/md5.h> 55 #include <sys/iconv.h> 56 57 #include "smb.h" 58 #include "smb_conn.h" 59 #include "smb_subr.h" 60 #include "smb_rq.h" 61 #include "smb_dev.h" 62 63 #include "opt_netsmb.h" 64 65 #include <crypto/des/des.h> 66 67 static u_char N8[] = {0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25}; 68 69 70 static void 71 smb_E(const u_char *key, u_char *data, u_char *dest) 72 { 73 des_key_schedule *ksp; 74 u_char kk[8]; 75 76 kk[0] = key[0] & 0xfe; 77 kk[1] = key[0] << 7 | (key[1] >> 1 & 0xfe); 78 kk[2] = key[1] << 6 | (key[2] >> 2 & 0xfe); 79 kk[3] = key[2] << 5 | (key[3] >> 3 & 0xfe); 80 kk[4] = key[3] << 4 | (key[4] >> 4 & 0xfe); 81 kk[5] = key[4] << 3 | (key[5] >> 5 & 0xfe); 82 kk[6] = key[5] << 2 | (key[6] >> 6 & 0xfe); 83 kk[7] = key[6] << 1; 84 ksp = kmalloc(sizeof(des_key_schedule), M_SMBTEMP, M_WAITOK); 85 des_set_key((des_cblock *)kk, *ksp); 86 des_ecb_encrypt((des_cblock *)data, (des_cblock *)dest, *ksp, 1); 87 kfree(ksp, M_SMBTEMP); 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 = kmalloc(14 + 21, M_SMBTEMP, M_WAITOK | M_ZERO); 96 P14 = p; 97 S21 = p + 14; 98 bcopy(apwd, P14, min(14, strlen(apwd))); 99 /* 100 * S21 = concat(Ex(P14, N8), zeros(5)); 101 */ 102 smb_E(P14, N8, S21); 103 smb_E(P14 + 7, N8, S21 + 8); 104 105 smb_E(S21, C8, RN); 106 smb_E(S21 + 7, C8, RN + 8); 107 smb_E(S21 + 14, C8, RN + 16); 108 kfree(p, M_SMBTEMP); 109 return 0; 110 } 111 112 int 113 smb_ntencrypt(const u_char *apwd, u_char *C8, u_char *RN) 114 { 115 u_char S21[21]; 116 u_int16_t *unipwd; 117 MD4_CTX *ctxp; 118 int len; 119 120 len = strlen(apwd); 121 unipwd = kmalloc((len + 1) * sizeof(u_int16_t), M_SMBTEMP, M_WAITOK); 122 /* 123 * S21 = concat(MD4(U(apwd)), zeros(5)); 124 */ 125 smb_strtouni(unipwd, apwd); 126 ctxp = kmalloc(sizeof(MD4_CTX), M_SMBTEMP, M_WAITOK); 127 MD4Init(ctxp); 128 MD4Update(ctxp, (u_char*)unipwd, len * sizeof(u_int16_t)); 129 kfree(unipwd, M_SMBTEMP); 130 bzero(S21, 21); 131 MD4Final(S21, ctxp); 132 kfree(ctxp, M_SMBTEMP); 133 134 smb_E(S21, C8, RN); 135 smb_E(S21 + 7, C8, RN + 8); 136 smb_E(S21 + 14, C8, RN + 16); 137 return 0; 138 } 139 140 /* 141 * Calculate message authentication code (MAC) key for virtual circuit. 142 */ 143 int 144 smb_calcmackey(struct smb_vc *vcp) 145 { 146 const char *pwd; 147 u_int16_t *unipwd; 148 int len; 149 MD4_CTX md4; 150 u_char S16[16], S21[21]; 151 152 KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE, 153 ("signatures not enabled")); 154 155 if (vcp->vc_mackey != NULL) { 156 kfree(vcp->vc_mackey, M_SMBTEMP); 157 vcp->vc_mackey = NULL; 158 vcp->vc_mackeylen = 0; 159 vcp->vc_seqno = 0; 160 } 161 162 /* 163 * The partial MAC key is the concatenation of the 16 byte session 164 * key and the 24 byte challenge response. 165 */ 166 vcp->vc_mackeylen = 16 + 24; 167 vcp->vc_mackey = kmalloc(vcp->vc_mackeylen, M_SMBTEMP, M_WAITOK); 168 169 /* 170 * Calculate session key: 171 * MD4(MD4(U(PN))) 172 */ 173 pwd = smb_vc_getpass(vcp); 174 len = strlen(pwd); 175 unipwd = kmalloc((len + 1) * sizeof(u_int16_t), M_SMBTEMP, M_WAITOK); 176 smb_strtouni(unipwd, pwd); 177 MD4Init(&md4); 178 MD4Update(&md4, (u_char *)unipwd, len * sizeof(u_int16_t)); 179 MD4Final(S16, &md4); 180 MD4Init(&md4); 181 MD4Update(&md4, S16, 16); 182 MD4Final(vcp->vc_mackey, &md4); 183 kfree(unipwd, M_SMBTEMP); 184 185 /* 186 * Calculate response to challenge: 187 * Ex(concat(MD4(U(pass)), zeros(5)), C8) 188 */ 189 bzero(S21, 21); 190 bcopy(S16, S21, 16); 191 smb_E(S21, vcp->vc_ch, vcp->vc_mackey + 16); 192 smb_E(S21 + 7, vcp->vc_ch, vcp->vc_mackey + 24); 193 smb_E(S21 + 14, vcp->vc_ch, vcp->vc_mackey + 32); 194 195 return (0); 196 } 197 198 /* 199 * Sign request with MAC. 200 */ 201 int 202 smb_rq_sign(struct smb_rq *rqp) 203 { 204 struct smb_vc *vcp = rqp->sr_vc; 205 struct mbchain *mbp; 206 struct mbuf *mb; 207 MD5_CTX md5; 208 u_char digest[16]; 209 210 KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE, 211 ("signatures not enabled")); 212 213 if (vcp->vc_mackey == NULL) 214 /* XXX Should assert that cmd == SMB_COM_NEGOTIATE. */ 215 return (0); 216 217 /* 218 * This is a bit of a kludge. If the request is non-TRANSACTION, 219 * or it is the first request of a transaction, give it the next 220 * sequence number, and expect the reply to have the sequence number 221 * following that one. Otherwise, it is a secondary request in 222 * a transaction, and it gets the same sequence numbers as the 223 * primary request. 224 */ 225 if (rqp->sr_t2 == NULL || 226 (rqp->sr_t2->t2_flags & SMBT2_SECONDARY) == 0) { 227 rqp->sr_seqno = vcp->vc_seqno++; 228 rqp->sr_rseqno = vcp->vc_seqno++; 229 } else { 230 /* 231 * Sequence numbers are already in the struct because 232 * smb_t2_request_int() uses the same one for all the 233 * requests in the transaction. 234 * (At least we hope so.) 235 */ 236 KASSERT(rqp->sr_t2 == NULL || 237 (rqp->sr_t2->t2_flags & SMBT2_SECONDARY) == 0 || 238 rqp->sr_t2->t2_rq == rqp, 239 ("sec t2 rq not using same smb_rq")); 240 } 241 242 /* Initialize sec. signature field to sequence number + zeros. */ 243 *(u_int32_t *)rqp->sr_rqsig = htole32(rqp->sr_seqno); 244 *(u_int32_t *)(rqp->sr_rqsig + 4) = 0; 245 246 /* 247 * Compute HMAC-MD5 of packet data, keyed by MAC key. 248 * Store the first 8 bytes in the sec. signature field. 249 */ 250 smb_rq_getrequest(rqp, &mbp); 251 MD5Init(&md5); 252 MD5Update(&md5, vcp->vc_mackey, vcp->vc_mackeylen); 253 for (mb = mbp->mb_top; mb != NULL; mb = mb->m_next) 254 MD5Update(&md5, mtod(mb, void *), mb->m_len); 255 MD5Final(digest, &md5); 256 bcopy(digest, rqp->sr_rqsig, 8); 257 258 return (0); 259 } 260 261 /* 262 * Verify reply signature. 263 */ 264 int 265 smb_rq_verify(struct smb_rq *rqp) 266 { 267 struct smb_vc *vcp = rqp->sr_vc; 268 struct mdchain *mdp; 269 u_char sigbuf[8]; 270 MD5_CTX md5; 271 u_char digest[16]; 272 struct mbuf *mb; 273 274 KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE, 275 ("signatures not enabled")); 276 277 if (vcp->vc_mackey == NULL) 278 /* XXX Should check that this is a SMB_COM_NEGOTIATE reply. */ 279 return (0); 280 281 /* 282 * Compute HMAC-MD5 of packet data, keyed by MAC key. 283 * We play games to pretend the security signature field 284 * contains their sequence number, to avoid modifying 285 * the packet itself. 286 */ 287 smb_rq_getreply(rqp, &mdp); 288 mb = mdp->md_top; 289 KASSERT(mb->m_len >= SMB_HDRLEN, ("forgot to m_pullup")); 290 MD5Init(&md5); 291 MD5Update(&md5, vcp->vc_mackey, vcp->vc_mackeylen); 292 MD5Update(&md5, mtod(mb, void *), 14); 293 *(u_int32_t *)sigbuf = htole32(rqp->sr_rseqno); 294 *(u_int32_t *)(sigbuf + 4) = 0; 295 MD5Update(&md5, sigbuf, 8); 296 MD5Update(&md5, mtod(mb, u_char *) + 22, mb->m_len - 22); 297 for (mb = mb->m_next; mb != NULL; mb = mb->m_next) 298 MD5Update(&md5, mtod(mb, void *), mb->m_len); 299 MD5Final(digest, &md5); 300 301 /* 302 * Now verify the signature. 303 */ 304 if (bcmp(mtod(mdp->md_top, u_char *) + 14, digest, 8) != 0) 305 return (EAUTH); 306 307 return (0); 308 } 309