/*-
* Copyright (c) 2000-2001, Boris Popov
* All rights reserved.
*
* Copyright (c) 2003, 2004 Tim J. Robbins.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Boris Popov.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/proc.h>
#include <sys/fcntl.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/endian.h>
#include <sys/mbuf.h>
#include <sys/mchain.h>
#include <sys/md4.h>
#include <sys/md5.h>
#include <sys/iconv.h>
#include <netsmb/smb.h>
#include <netsmb/smb_conn.h>
#include <netsmb/smb_subr.h>
#include <netsmb/smb_rq.h>
#include <netsmb/smb_dev.h>
#include <crypto/des/des.h>
#include "opt_netsmb.h"
static u_char N8[] = {0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25};
static void
smb_E(const u_char *key, u_char *data, u_char *dest)
{
des_key_schedule *ksp;
u_char kk[8];
kk[0] = key[0] & 0xfe;
kk[1] = key[0] << 7 | (key[1] >> 1 & 0xfe);
kk[2] = key[1] << 6 | (key[2] >> 2 & 0xfe);
kk[3] = key[2] << 5 | (key[3] >> 3 & 0xfe);
kk[4] = key[3] << 4 | (key[4] >> 4 & 0xfe);
kk[5] = key[4] << 3 | (key[5] >> 5 & 0xfe);
kk[6] = key[5] << 2 | (key[6] >> 6 & 0xfe);
kk[7] = key[6] << 1;
ksp = malloc(sizeof(des_key_schedule), M_SMBTEMP, M_WAITOK);
des_set_key((des_cblock *)kk, *ksp);
des_ecb_encrypt((des_cblock *)data, (des_cblock *)dest, *ksp, 1);
free(ksp, M_SMBTEMP);
}
int
smb_encrypt(const u_char *apwd, u_char *C8, u_char *RN)
{
u_char *p, *P14, *S21;
p = malloc(14 + 21, M_SMBTEMP, M_WAITOK);
bzero(p, 14 + 21);
P14 = p;
S21 = p + 14;
bcopy(apwd, P14, min(14, strlen(apwd)));
/*
* S21 = concat(Ex(P14, N8), zeros(5));
*/
smb_E(P14, N8, S21);
smb_E(P14 + 7, N8, S21 + 8);
smb_E(S21, C8, RN);
smb_E(S21 + 7, C8, RN + 8);
smb_E(S21 + 14, C8, RN + 16);
free(p, M_SMBTEMP);
return 0;
}
int
smb_ntencrypt(const u_char *apwd, u_char *C8, u_char *RN)
{
u_char S21[21];
u_int16_t *unipwd;
MD4_CTX *ctxp;
int len;
len = strlen(apwd);
unipwd = malloc((len + 1) * sizeof(u_int16_t), M_SMBTEMP, M_WAITOK);
/*
* S21 = concat(MD4(U(apwd)), zeros(5));
*/
smb_strtouni(unipwd, apwd);
ctxp = malloc(sizeof(MD4_CTX), M_SMBTEMP, M_WAITOK);
MD4Init(ctxp);
MD4Update(ctxp, (u_char*)unipwd, len * sizeof(u_int16_t));
free(unipwd, M_SMBTEMP);
bzero(S21, 21);
MD4Final(S21, ctxp);
free(ctxp, M_SMBTEMP);
smb_E(S21, C8, RN);
smb_E(S21 + 7, C8, RN + 8);
smb_E(S21 + 14, C8, RN + 16);
return 0;
}
/*
* Calculate message authentication code (MAC) key for virtual circuit.
*/
int
smb_calcmackey(struct smb_vc *vcp)
{
const char *pwd;
u_int16_t *unipwd;
int len;
MD4_CTX md4;
u_char S16[16], S21[21];
KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
("signatures not enabled"));
if (vcp->vc_mackey != NULL) {
free(vcp->vc_mackey, M_SMBTEMP);
vcp->vc_mackey = NULL;
vcp->vc_mackeylen = 0;
vcp->vc_seqno = 0;
}
/*
* The partial MAC key is the concatenation of the 16 byte session
* key and the 24 byte challenge response.
*/
vcp->vc_mackeylen = 16 + 24;
vcp->vc_mackey = malloc(vcp->vc_mackeylen, M_SMBTEMP, M_WAITOK);
/*
* Calculate session key:
* MD4(MD4(U(PN)))
*/
pwd = smb_vc_getpass(vcp);
len = strlen(pwd);
unipwd = malloc((len + 1) * sizeof(u_int16_t), M_SMBTEMP, M_WAITOK);
smb_strtouni(unipwd, pwd);
MD4Init(&md4);
MD4Update(&md4, (u_char *)unipwd, len * sizeof(u_int16_t));
MD4Final(S16, &md4);
MD4Init(&md4);
MD4Update(&md4, S16, 16);
MD4Final(vcp->vc_mackey, &md4);
free(unipwd, M_SMBTEMP);
/*
* Calculate response to challenge:
* Ex(concat(MD4(U(pass)), zeros(5)), C8)
*/
bzero(S21, 21);
bcopy(S16, S21, 16);
smb_E(S21, vcp->vc_ch, vcp->vc_mackey + 16);
smb_E(S21 + 7, vcp->vc_ch, vcp->vc_mackey + 24);
smb_E(S21 + 14, vcp->vc_ch, vcp->vc_mackey + 32);
return (0);
}
/*
* Sign request with MAC.
*/
int
smb_rq_sign(struct smb_rq *rqp)
{
struct smb_vc *vcp = rqp->sr_vc;
struct mbchain *mbp;
struct mbuf *mb;
MD5_CTX md5;
u_char digest[16];
KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
("signatures not enabled"));
if (vcp->vc_mackey == NULL)
/* XXX Should assert that cmd == SMB_COM_NEGOTIATE. */
return (0);
/*
* This is a bit of a kludge. If the request is non-TRANSACTION,
* or it is the first request of a transaction, give it the next
* sequence number, and expect the reply to have the sequence number
* following that one. Otherwise, it is a secondary request in
* a transaction, and it gets the same sequence numbers as the
* primary request.
*/
if (rqp->sr_t2 == NULL ||
(rqp->sr_t2->t2_flags & SMBT2_SECONDARY) == 0) {
rqp->sr_seqno = vcp->vc_seqno++;
rqp->sr_rseqno = vcp->vc_seqno++;
} else {
/*
* Sequence numbers are already in the struct because
* smb_t2_request_int() uses the same one for all the
* requests in the transaction.
* (At least we hope so.)
*/
KASSERT(rqp->sr_t2 == NULL ||
(rqp->sr_t2->t2_flags & SMBT2_SECONDARY) == 0 ||
rqp->sr_t2->t2_rq == rqp,
("sec t2 rq not using same smb_rq"));
}
/* Initialize sec. signature field to sequence number + zeros. */
le32enc(rqp->sr_rqsig, rqp->sr_seqno);
le32enc(rqp->sr_rqsig + 4, 0);
/*
* Compute HMAC-MD5 of packet data, keyed by MAC key.
* Store the first 8 bytes in the sec. signature field.
*/
smb_rq_getrequest(rqp, &mbp);
MD5Init(&md5);
MD5Update(&md5, vcp->vc_mackey, vcp->vc_mackeylen);
for (mb = mbp->mb_top; mb != NULL; mb = mb->m_next)
MD5Update(&md5, mtod(mb, void *), mb->m_len);
MD5Final(digest, &md5);
bcopy(digest, rqp->sr_rqsig, 8);
return (0);
}
/*
* Verify reply signature.
*/
int
smb_rq_verify(struct smb_rq *rqp)
{
struct smb_vc *vcp = rqp->sr_vc;
struct mdchain *mdp;
u_char sigbuf[8];
MD5_CTX md5;
u_char digest[16];
struct mbuf *mb;
KASSERT(vcp->vc_hflags2 & SMB_FLAGS2_SECURITY_SIGNATURE,
("signatures not enabled"));
if (vcp->vc_mackey == NULL)
/* XXX Should check that this is a SMB_COM_NEGOTIATE reply. */
return (0);
/*
* Compute HMAC-MD5 of packet data, keyed by MAC key.
* We play games to pretend the security signature field
* contains their sequence number, to avoid modifying
* the packet itself.
*/
smb_rq_getreply(rqp, &mdp);
mb = mdp->md_top;
KASSERT(mb->m_len >= SMB_HDRLEN, ("forgot to m_pullup"));
MD5Init(&md5);
MD5Update(&md5, vcp->vc_mackey, vcp->vc_mackeylen);
MD5Update(&md5, mtod(mb, void *), 14);
*(u_int32_t *)sigbuf = htole32(rqp->sr_rseqno);
*(u_int32_t *)(sigbuf + 4) = 0;
MD5Update(&md5, sigbuf, 8);
MD5Update(&md5, mtod(mb, u_char *) + 22, mb->m_len - 22);
for (mb = mb->m_next; mb != NULL; mb = mb->m_next)
MD5Update(&md5, mtod(mb, void *), mb->m_len);
MD5Final(digest, &md5);
/*
* Now verify the signature.
*/
if (bcmp(mtod(mdp->md_top, u_char *) + 14, digest, 8) != 0)
return (EAUTH);
return (0);
}
