/*
* fs/cifs/cifsencrypt.c
*
* Encryption and hashing operations relating to NTLM, NTLMv2. See MS-NLMP
* for more detailed information
*
* Copyright (C) International Business Machines Corp., 2005,2013
* Author(s): Steve French (sfrench@us.ibm.com)
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/fs.h>
#include <linux/slab.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifs_debug.h"
#include "cifs_unicode.h"
#include "cifsproto.h"
#include "ntlmssp.h"
#include <linux/ctype.h>
#include <linux/random.h>
#include <linux/highmem.h>
#include <crypto/skcipher.h>
#include <crypto/aead.h>
static int
cifs_crypto_shash_md5_allocate(struct TCP_Server_Info *server)
{
int rc;
unsigned int size;
if (server->secmech.sdescmd5 != NULL)
return 0; /* already allocated */
server->secmech.md5 = crypto_alloc_shash("md5", 0, 0);
if (IS_ERR(server->secmech.md5)) {
cifs_dbg(VFS, "could not allocate crypto md5\n");
rc = PTR_ERR(server->secmech.md5);
server->secmech.md5 = NULL;
return rc;
}
size = sizeof(struct shash_desc) +
crypto_shash_descsize(server->secmech.md5);
server->secmech.sdescmd5 = kmalloc(size, GFP_KERNEL);
if (!server->secmech.sdescmd5) {
crypto_free_shash(server->secmech.md5);
server->secmech.md5 = NULL;
return -ENOMEM;
}
server->secmech.sdescmd5->shash.tfm = server->secmech.md5;
server->secmech.sdescmd5->shash.flags = 0x0;
return 0;
}
int __cifs_calc_signature(struct smb_rqst *rqst,
struct TCP_Server_Info *server, char *signature,
struct shash_desc *shash)
{
int i;
int rc;
struct kvec *iov = rqst->rq_iov;
int n_vec = rqst->rq_nvec;
if (n_vec < 2 || iov[0].iov_len != 4)
return -EIO;
for (i = 1; i < n_vec; i++) {
if (iov[i].iov_len == 0)
continue;
if (iov[i].iov_base == NULL) {
cifs_dbg(VFS, "null iovec entry\n");
return -EIO;
}
if (i == 1 && iov[1].iov_len <= 4)
break; /* nothing to sign or corrupt header */
rc = crypto_shash_update(shash,
iov[i].iov_base, iov[i].iov_len);
if (rc) {
cifs_dbg(VFS, "%s: Could not update with payload\n",
__func__);
return rc;
}
}
/* now hash over the rq_pages array */
for (i = 0; i < rqst->rq_npages; i++) {
void *kaddr = kmap(rqst->rq_pages[i]);
size_t len = rqst->rq_pagesz;
if (i == rqst->rq_npages - 1)
len = rqst->rq_tailsz;
crypto_shash_update(shash, kaddr, len);
kunmap(rqst->rq_pages[i]);
}
rc = crypto_shash_final(shash, signature);
if (rc)
cifs_dbg(VFS, "%s: Could not generate hash\n", __func__);
return rc;
}
/*
* Calculate and return the CIFS signature based on the mac key and SMB PDU.
* The 16 byte signature must be allocated by the caller. Note we only use the
* 1st eight bytes and that the smb header signature field on input contains
* the sequence number before this function is called. Also, this function
* should be called with the server->srv_mutex held.
*/
static int cifs_calc_signature(struct smb_rqst *rqst,
struct TCP_Server_Info *server, char *signature)
{
int rc;
if (!rqst->rq_iov || !signature || !server)
return -EINVAL;
if (!server->secmech.sdescmd5) {
rc = cifs_crypto_shash_md5_allocate(server);
if (rc) {
cifs_dbg(VFS, "%s: Can't alloc md5 crypto\n", __func__);
return -1;
}
}
rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
if (rc) {
cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
return rc;
}
rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
server->session_key.response, server->session_key.len);
if (rc) {
cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
return rc;
}
return __cifs_calc_signature(rqst,