original development tree for Linux kernel GTP module; now long in mainline.
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/*
* 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 <linux/slab.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifs_debug.h"
#include "md5.h"
#include "cifs_unicode.h"
#include "cifsproto.h"
#include <linux/ctype.h>
#include <linux/random.h>
/* 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 */
/* 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);
extern void SMBencrypt(unsigned char *passwd, const unsigned char *c8,
unsigned char *p24);
static int cifs_calculate_signature(const struct smb_hdr *cifs_pdu,
const struct mac_key *key, char *signature)
{
struct MD5Context context;
if ((cifs_pdu == NULL) || (signature == NULL) || (key == NULL))
return -EINVAL;
cifs_MD5_init(&context);
cifs_MD5_update(&context, (char *)&key->data, key->len);
cifs_MD5_update(&context, cifs_pdu->Protocol, cifs_pdu->smb_buf_length);
cifs_MD5_final(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 struct mac_key *key, char *signature)
{
struct MD5Context context;
int i;
if ((iov == NULL) || (signature == NULL) || (key == NULL))
return -EINVAL;
cifs_MD5_init(&context);
cifs_MD5_update(&context, (char *)&key->data, key->len);
for (i = 0; i < n_vec; i++) {
if (iov[i].iov_len == 0)
continue;
if (iov[i].iov_base == NULL) {
cERROR(1, "null iovec entry");
return -EIO;
}
/* 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 */
cifs_MD5_update(&context, iov[0].iov_base+4,
iov[0].iov_len-4);
} else
cifs_MD5_update(&context, iov[i].iov_base, iov[i].iov_len);
}
cifs_MD5_final(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 struct mac_key *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(struct mac_key *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->data.ntlm, temp_key, 16);
memcpy(key->data.ntlm+16, rn, CIFS_SESS_KEY_SIZE);
key->len = 40;
return 0;
}
int CalcNTLMv2_partial_mac_key(struct cifsSesInfo *ses,
const 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->ntlmv2_hash, &ctx);
kfree(ucase_buf);
kfree(unicode_buf);
return 0;
}
#ifdef CONFIG_CIFS_WEAK_PW_HASH
void calc_lanman_hash(const char *password, const char *cryptkey, bool encrypt,
char *lnm_session_key)
{
int i;
char password_with_pad[CIFS_ENCPWD_SIZE];
memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
if (password)
strncpy(password_with_pad, password, CIFS_ENCPWD_SIZE);
if (!encrypt && extended_security & CIFSSEC_MAY_PLNTXT) {
memset(lnm_session_key, 0, CIFS_SESS_KEY_SIZE);
memcpy(lnm_session_key, password_with_pad,
CIFS_ENCPWD_SIZE);
return;
}
/* calculate old style session key */
/* calling toupper is less broken than repeatedly
calling nls_toupper would be since that will never
work for UTF8, but neither handles multibyte code pages
but the only alternative would be converting to UCS-16 (Unicode)
(using a routine something like UniStrupr) then
uppercasing and then converting back from Unicode - which
would only worth doing it if we knew it were utf8. Basically
utf8 and other multibyte codepages each need their own strupper
function since a byte at a time will ont work. */
for (i = 0; i < CIFS_ENCPWD_SIZE; i++)
password_with_pad[i] = toupper(password_with_pad[i]);
SMBencrypt(password_with_pad, cryptkey, lnm_session_key);
/* clear password before we return/free memory */
memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
}
#endif /* CIFS_WEAK_PW_HASH */
static int calc_ntlmv2_hash(struct cifsSesInfo *ses,
const struct nls_table *nls_cp)
{
int rc = 0;
int len;
char nt_hash[16];
struct HMACMD5Context *pctxt;
wchar_t *user;
wchar_t *domain;
pctxt = kmalloc(sizeof(struct HMACMD5Context), GFP_KERNEL);
if (pctxt == NULL)
return -ENOMEM;
/* calculate md4 hash of password */
E_md4hash(ses->password, nt_hash);
/* convert Domainname to unicode and uppercase */
hmac_md5_init_limK_to_64(nt_hash, 16, pctxt);
/* convert ses->userName to unicode and uppercase */
len = strlen(ses->userName);
user = kmalloc(2 + (len * 2), GFP_KERNEL);
if (user == NULL)
goto calc_exit_2;
len = cifs_strtoUCS((__le16 *)user, ses->userName, len, nls_cp);
UniStrupr(user);
hmac_md5_update((char *)user, 2*len, pctxt);
/* convert ses->domainName to unicode and uppercase */
if (ses->domainName) {
len = strlen(ses->domainName);
domain = kmalloc(2 + (len * 2), GFP_KERNEL);
if (domain == NULL)
goto calc_exit_1;
len = cifs_strtoUCS((__le16 *)domain, ses->domainName, len,
nls_cp);
/* the following line was removed since it didn't work well
with lower cased domain name that passed as an option.
Maybe converting the domain name earlier makes sense */
/* UniStrupr(domain); */
hmac_md5_update((char *)domain, 2*len, pctxt);
kfree(domain);
}
calc_exit_1:
kfree(user);
calc_exit_2:
/* BB FIXME what about bytes 24 through 40 of the signing key?
compare with the NTLM example */
hmac_md5_final(ses->server->ntlmv2_hash, pctxt);
kfree(pctxt);
return rc;
}
void setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf,
const struct nls_table *nls_cp)
{
int rc;
struct ntlmv2_resp *buf = (struct ntlmv2_resp *)resp_buf;
struct HMACMD5Context context;
buf->blob_signature = cpu_to_le32(0x00000101);
buf->reserved = 0;
buf->time = cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
get_random_bytes(&buf->client_chal, sizeof(buf->client_chal));
buf->reserved2 = 0;
buf->names[0].type = cpu_to_le16(NTLMSSP_DOMAIN_TYPE);
buf->names[0].length = 0;
buf->names[1].type = 0;
buf->names[1].length = 0;
/* calculate buf->ntlmv2_hash */
rc = calc_ntlmv2_hash(ses, nls_cp);
if (rc)
cERROR(1, "could not get v2 hash rc %d", rc);
CalcNTLMv2_response(ses, resp_buf);
/* now calculate the MAC key for NTLMv2 */
hmac_md5_init_limK_to_64(ses->server->ntlmv2_hash, 16, &context);
hmac_md5_update(resp_buf, 16, &context);
hmac_md5_final(ses->server->mac_signing_key.data.ntlmv2.key, &context);
memcpy(&ses->server->mac_signing_key.data.ntlmv2.resp, resp_buf,
sizeof(struct ntlmv2_resp));
ses->server->mac_signing_key.len = 16 + sizeof(struct ntlmv2_resp);
}
void CalcNTLMv2_response(const struct cifsSesInfo *ses,
char *v2_session_response)
{
struct HMACMD5Context context;
/* rest of v2 struct already generated */
memcpy(v2_session_response + 8, ses->server->cryptKey, 8);
hmac_md5_init_limK_to_64(ses->server->ntlmv2_hash, 16, &context);
hmac_md5_update(v2_session_response+8,
sizeof(struct ntlmv2_resp) - 8, &context);
hmac_md5_final(v2_session_response, &context);
/* cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); */
}