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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* SMB MAC Signing support.
*/
#include <strings.h>
#include <security/cryptoki.h>
#include <security/pkcs11.h>
#include <smbsrv/libsmb.h>
#include <smbsrv/smb.h>
/*
* smb_mac_init
*
* Calculates the MAC key using the specified user session
* key (NTLM or NTLMv2).
*
* Returns SMBAUTH_SUCCESS if key generation was successful,
* SMBAUTH_FAILURE if not.
*/
int
smb_mac_init(smb_sign_ctx_t *sign_ctx, smb_auth_info_t *auth)
{
unsigned char S16[SMBAUTH_SESSION_KEY_SZ];
if (smb_auth_gen_session_key(auth, S16) != SMBAUTH_SUCCESS)
return (SMBAUTH_FAILURE);
bcopy(S16, sign_ctx->ssc_mackey, SMBAUTH_SESSION_KEY_SZ);
bcopy(auth->cs, &(sign_ctx->ssc_mackey[SMBAUTH_SESSION_KEY_SZ]),
auth->cs_len);
sign_ctx->ssc_keylen = SMBAUTH_SESSION_KEY_SZ + auth->cs_len;
return (SMBAUTH_SUCCESS);
}
/*
* smb_mac_calc
*
* Calculates MAC signature for the given buffer and returns
* it in the mac_sign parameter.
*
* The MAC signature is calculated as follows:
*
* data = concat(MAC_Key, MAC_Key_Len, SMB_Msg, SMB_Msg_Len);
* hash = MD5(data);
* MAC = head(hash, 8);
*
* The tricky part is that a sequence number should be used
* in calculation instead of the signature field in the
* SMB header.
*
* Returns SMBAUTH_SUCCESS if cryptology framework use was successful,
* SMBAUTH_FAILURE if not.
*/
int
smb_mac_calc(smb_sign_ctx_t *sign_ctx, const unsigned char *buf,
size_t buf_len, unsigned char *mac_sign)
{
CK_RV rv;
CK_MECHANISM mechanism;
CK_SESSION_HANDLE hSession;
unsigned long diglen = MD_DIGEST_LEN;
int rc = SMBAUTH_FAILURE;
int offset_end_of_sig = (SMB_SIG_OFFS + SMB_SIG_SIZE);
unsigned char seq_buf[SMB_SIG_SIZE];
unsigned char mac[16];
/*
* put seq_num into the first 4 bytes and
* zero out the next 4 bytes
*/
bcopy(&sign_ctx->ssc_seqnum, seq_buf, 4);
bzero(seq_buf + 4, 4);
mechanism.mechanism = CKM_MD5;
mechanism.pParameter = 0;
mechanism.ulParameterLen = 0;
rv = SUNW_C_GetMechSession(mechanism.mechanism, &hSession);
if (rv != CKR_OK)
return (SMBAUTH_FAILURE);
/* Initialize the digest operation in the session */
rv = C_DigestInit(hSession, &mechanism);
if (rv != CKR_OK)
goto smbmacdone;
/* init with the MAC key */
rv = C_DigestUpdate(hSession, sign_ctx->ssc_mackey,
sign_ctx->ssc_keylen);
if (rv != CKR_OK)
goto smbmacdone;
/* copy in SMB packet info till signature field */
rv = C_DigestUpdate(hSession, (CK_BYTE_PTR)buf, SMB_SIG_OFFS);
if (rv != CKR_OK)
goto smbmacdone;
/* copy in the seq_buf instead of the signature */
rv = C_DigestUpdate(hSession, seq_buf, sizeof (seq_buf));
if (rv != CKR_OK)
goto smbmacdone;
/* copy in the rest of the packet, skipping the signature */
rv = C_DigestUpdate(hSession, (CK_BYTE_PTR)buf + offset_end_of_sig,
buf_len - offset_end_of_sig);
if (rv != CKR_OK)
goto smbmacdone;
rv = C_DigestFinal(hSession, mac, &diglen);
if (rv != CKR_OK)
goto smbmacdone;
bcopy(mac, mac_sign, SMB_SIG_SIZE);
rc = SMBAUTH_SUCCESS;
smbmacdone:
(void) C_CloseSession(hSession);
return (rc);
}
/*
* smb_mac_chk
*
* Calculates MAC signature for the given buffer
* and compares it to the signature in the given context.
* Return 1 if the signature are match, otherwise, return (0);
*/
int
smb_mac_chk(smb_sign_ctx_t *sign_ctx,
const unsigned char *buf, size_t buf_len)
{
unsigned char mac_sign[SMB_SIG_SIZE];
/* calculate mac signature */
if (smb_mac_calc(sign_ctx, buf, buf_len, mac_sign) != SMBAUTH_SUCCESS)
return (0);
/* compare the signatures */
if (memcmp(sign_ctx->ssc_sign, mac_sign, SMB_SIG_SIZE) == 0)
return (1);
return (0);
}
/*
* smb_mac_sign
*
* Calculates MAC signature for the given buffer,
* and write it to the buffer's signature field.
*
* Returns SMBAUTH_SUCCESS if cryptology framework use was successful,
* SMBAUTH_FAILURE if not.
*/
int
smb_mac_sign(smb_sign_ctx_t *sign_ctx, unsigned char *buf, size_t buf_len)
{
unsigned char mac_sign[SMB_SIG_SIZE];
/* calculate mac signature */
if (smb_mac_calc(sign_ctx, buf, buf_len, mac_sign) != SMBAUTH_SUCCESS)
return (SMBAUTH_FAILURE);
/* put mac signature in the header's signature field */
(void) memcpy(buf + SMB_SIG_OFFS, mac_sign, SMB_SIG_SIZE);
return (SMBAUTH_SUCCESS);
}
void
smb_mac_inc_seqnum(smb_sign_ctx_t *sign_ctx)
{
sign_ctx->ssc_seqnum++;
}
void
smb_mac_dec_seqnum(smb_sign_ctx_t *sign_ctx)
{
sign_ctx->ssc_seqnum--;
}
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