/*
* fs/cifs/cifsencrypt.c
*
* Copyright (C) International Business Machines Corp., 2005,2006
* 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 "cifspdu.h"
#include "cifsglob.h"
#include "cifs_debug.h"
#include "md5.h"
#include "cifs_unicode.h"
#include "cifsproto.h"
/* Calculate and return the CIFS signature based on the mac key and the smb pdu */
/* the 16 byte signature must be allocated by the caller */
/* Note we only use the 1st eight bytes */
/* Note that the smb header signature field on input contains the
sequence number before this function is called */
extern void mdfour(unsigned char *out, unsigned char *in, int n);
extern void E_md4hash(const unsigned char *passwd, unsigned char *p16);
static int cifs_calculate_signature(const struct smb_hdr * cifs_pdu,
const char * key, char * signature)
{
struct MD5Context context;
if((cifs_pdu == NULL) || (signature == NULL))
return -EINVAL;
MD5Init(&context);
MD5Update(&context,key,CIFS_SESSION_KEY_SIZE+16);
MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length);
MD5Final(signature,&context);
return 0;
}
int cifs_sign_smb(struct smb_hdr * cifs_pdu, struct TCP_Server_Info * server,
__u32 * pexpected_response_sequence_number)
{
int rc = 0;
char smb_signature[20];
if((cifs_pdu == NULL) || (server == NULL))
return -EINVAL;
if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
return rc;
spin_lock(&GlobalMid_Lock);
cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(server->sequence_number);
cifs_pdu->Signature.Sequence.Reserved = 0;
*pexpected_response_sequence_number = server->sequence_number++;
server->sequence_number++;
spin_unlock(&GlobalMid_Lock);
rc = cifs_calculate_signature(cifs_pdu, server->mac_signing_key,smb_signature);
if(rc)
memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
else
memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
return rc;
}
static int cifs_calc_signature2(const struct kvec * iov, int n_vec,
const char * key, char * signature)
{
struct MD5Context context;
int i;
if((iov == NULL) || (signature == NULL))
return -EINVAL;
MD5Init(&context);
MD5Update(&context,key,CIFS_SESSION_KEY_SIZE+16);
for(i=0;i<n_vec;i++) {
if(iov[i].iov_base == NULL) {
cERROR(1,("null iovec entry"));
return -EIO;
} else if(iov[i].iov_len == 0)
break; /* bail out if we are sent nothing to sign */
/* The first entry includes a length field (which does not get
signed that occupies the first 4 bytes before the header */
if(i==0) {
if (iov[0].iov_len <= 8 ) /* cmd field at offset 9 */
break; /* nothing to sign or corrupt header */
MD5Update(&context,iov[0].iov_base+4, iov[0].iov_len-4);
} else
MD5Update(&context,iov[i].iov_base, iov[i].iov_len);
}
MD5Final(signature,&context);
return 0;
}
int cifs_sign_smb2(struct kvec * iov, int n_vec, struct TCP_Server_Info *server,
__u32 * pexpected_response_sequence_number)
{
int rc = 0;
char smb_signature[20];
struct smb_hdr * cifs_pdu = iov[0].iov_base;
if((cifs_pdu == NULL) || (server == NULL))
return -EINVAL;
if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
return rc;
spin_lock(&GlobalMid_Lock);
cifs_pdu->Signature.Sequence.SequenceNumber =
cpu_to_le32(server->sequence_number);
cifs_pdu->Signature.Sequence.Reserved = 0;
*pexpected_response_sequence_number = server->sequence_number++;
server->sequence_number++;
spin_unlock(&GlobalMid_Lock);
rc = cifs_calc_signature2(iov, n_vec, server->mac_signing_key,
smb_signature);
if(rc)
memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
else
memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
return rc;
}
int cifs_verify_signature(struct smb_hdr * cifs_pdu, const char * mac_key,
__u32 expected_sequence_number)
{
unsigned int rc;
char server_response_sig[8];
char what_we_think_sig_should_be[20];
if((cifs_pdu == NULL) || (mac_key == NULL))
return -EINVAL;
if (cifs_pdu->Command == SMB_COM_NEGOTIATE)
return 0;
if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
struct smb_com_lock_req * pSMB = (struct smb_com_lock_req *)cifs_pdu;
if(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
return 0;
}
/* BB what if signatures are supposed to be on for session but server does not
send one? BB */
/* Do not need to verify session setups with signature "BSRSPYL " */
if(memcmp(cifs_pdu->Signature.SecuritySignature,"BSRSPYL ",8)==0)
cFYI(1,("dummy signature received for smb command 0x%x",cifs_pdu->Command));
/* save off the origiginal signature so we can modify the smb and check
its signature against what the server sent */
memcpy(server_response_sig,cifs_pdu->Signature.SecuritySignature,8);
cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(expected_sequence_number);
cifs_pdu->Signature.Sequence.Reserved = 0;
rc = cifs_calculate_signature(cifs_pdu, mac_key,
what_we_think_sig_should_be);
if(rc)
return rc;
/* cifs_dump_mem("what we think it should be: ",what_we_think_sig_should_be,16); */
if(memcmp(server_response_sig, what_we_think_sig_should_be, 8))
return -EACCES;
else
return 0;
}
/* We fill in key by putting in 40 byte array which was allocated by caller */
int cifs_calculate_mac_key(char * key, const char * rn, const char * password)
{
char temp_key[16];
if ((key == NULL) || (rn == NULL))
return -EINVAL;
E_md4hash(password, temp_key);
mdfour(key,temp_key,16);
memcpy(key+16,rn, CIFS_SESSION_KEY_SIZE);
return 0;
}
int CalcNTLMv2_partial_mac_key(struct cifsSesInfo * ses, struct nls_table * nls_info)
{
char temp_hash[16];
struct HMACMD5Context ctx;
char * ucase_buf;
__le16 * unicode_buf;
unsigned int i,user_name_len,dom_name_len;
if(ses == NULL)
return -EINVAL;
E_md4hash(ses->password, temp_hash);
hmac_md5_init_limK_to_64(temp_hash, 16, &ctx);
user_name_len = strlen(ses->userName);
if(user_name_len > MAX_USERNAME_SIZE)
return -EINVAL;
if(ses->domainName == NULL)
return -EINVAL; /* BB should we use CIFS_LINUX_DOM */
dom_name_len = strlen(ses->domainName);
if(dom_name_len > MAX_USERNAME_SIZE)
return -EINVAL;
ucase_buf = kmalloc((MAX_USERNAME_SIZE+1), GFP_KERNEL);
if(ucase_buf == NULL)
return -ENOMEM;
unicode_buf = kmalloc((MAX_USERNAME_SIZE+1)*4, GFP_KERNEL);
if(unicode_buf == NULL) {
kfree(ucase_buf);
return -ENOMEM;
}
for(i=0;i<user_name_len;i++)
ucase_buf[i] = nls_info->charset2upper[(int)ses->userName[i]];
ucase_buf[i] = 0;
user_name_len = cifs_strtoUCS(unicode_buf, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
unicode_buf[user_name_len] = 0;
user_name_len++;
for(i=0;i<dom_name_len;i++)
ucase_buf[i] = nls_info->charset2upper[(int)ses->domainName[i]];
ucase_buf[i] = 0;
dom_name_len = cifs_strtoUCS(unicode_buf+user_name_len, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
unicode_buf[user_name_len + dom_name_len] = 0;
hmac_md5_update((const unsigned char *) unicode_buf,
(user_name_len+dom_name_len)*2,&ctx);
hmac_md5_final(ses->server->mac_signing_key,&ctx);
kfree(ucase_buf);
kfree(unicode_buf);
return 0;
}
void CalcNTLMv2_response(const struct cifsSesInfo * ses,char * v2_session_response)
{
struct HMACMD5Context context;
memcpy(v2_session_response + 8, ses->server->cryptKey,8);
/* gen_blob(v2_session_response + 16); */
hmac_md5_init_limK_to_64(ses->server->mac_signing_key, 16, &context);
hmac_md5_update(ses->server->cryptKey,8,&context);
/* hmac_md5_update(v2_session_response+16)client thing,8,&context); */ /* BB fix */
hmac_md5_final(v2_session_response,&context);
cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); /* BB removeme BB */
}
