fs/cifs/smb2transport.c - kernel/msm-4.9 - Gitiles

 /*
  *   fs/cifs/smb2transport.c
  *
  *   Copyright (C) International Business Machines  Corp., 2002, 2011
  *                 Etersoft, 2012
  *   Author(s): Steve French (sfrench@us.ibm.com)
  *              Jeremy Allison (jra@samba.org) 2006
  *              Pavel Shilovsky (pshilovsky@samba.org) 2012
  *
  *   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/list.h>
 #include <linux/wait.h>
 #include <linux/net.h>
 #include <linux/delay.h>
 #include <linux/uaccess.h>
 #include <asm/processor.h>
 #include <linux/mempool.h>
 #include <linux/highmem.h>
 #include "smb2pdu.h"
 #include "cifsglob.h"
 #include "cifsproto.h"
 #include "smb2proto.h"
 #include "cifs_debug.h"
 #include "smb2status.h"
 #include "smb2glob.h"

 static int
 smb2_crypto_shash_allocate(struct TCP_Server_Info *server)
 {
 	int rc;
 	unsigned int size;

 	if (server->secmech.sdeschmacsha256 != NULL)
 		return 0; /* already allocated */

 	server->secmech.hmacsha256 = crypto_alloc_shash("hmac(sha256)", 0, 0);
 	if (IS_ERR(server->secmech.hmacsha256)) {
 		cifs_dbg(VFS, "could not allocate crypto hmacsha256\n");
 		rc = PTR_ERR(server->secmech.hmacsha256);
 		server->secmech.hmacsha256 = NULL;
 		return rc;
 	}

 	size = sizeof(struct shash_desc) +
 			crypto_shash_descsize(server->secmech.hmacsha256);
 	server->secmech.sdeschmacsha256 = kmalloc(size, GFP_KERNEL);
 	if (!server->secmech.sdeschmacsha256) {
 		crypto_free_shash(server->secmech.hmacsha256);
 		server->secmech.hmacsha256 = NULL;
 		return -ENOMEM;
 	}
 	server->secmech.sdeschmacsha256->shash.tfm = server->secmech.hmacsha256;
 	server->secmech.sdeschmacsha256->shash.flags = 0x0;

 	return 0;
 }

 static int
 smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
 {
 	unsigned int size;
 	int rc;

 	if (server->secmech.sdesccmacaes != NULL)
 		return 0;  /* already allocated */

 	rc = smb2_crypto_shash_allocate(server);
 	if (rc)
 		return rc;

 	server->secmech.cmacaes = crypto_alloc_shash("cmac(aes)", 0, 0);
 	if (IS_ERR(server->secmech.cmacaes)) {
 		cifs_dbg(VFS, "could not allocate crypto cmac-aes");
 		kfree(server->secmech.sdeschmacsha256);
 		server->secmech.sdeschmacsha256 = NULL;
 		crypto_free_shash(server->secmech.hmacsha256);
 		server->secmech.hmacsha256 = NULL;
 		rc = PTR_ERR(server->secmech.cmacaes);
 		server->secmech.cmacaes = NULL;
 		return rc;
 	}

 	size = sizeof(struct shash_desc) +
 			crypto_shash_descsize(server->secmech.cmacaes);
 	server->secmech.sdesccmacaes = kmalloc(size, GFP_KERNEL);
 	if (!server->secmech.sdesccmacaes) {
 		cifs_dbg(VFS, "%s: Can't alloc cmacaes\n", __func__);
 		kfree(server->secmech.sdeschmacsha256);
 		server->secmech.sdeschmacsha256 = NULL;
 		crypto_free_shash(server->secmech.hmacsha256);
 		crypto_free_shash(server->secmech.cmacaes);
 		server->secmech.hmacsha256 = NULL;
 		server->secmech.cmacaes = NULL;
 		return -ENOMEM;
 	}
 	server->secmech.sdesccmacaes->shash.tfm = server->secmech.cmacaes;
 	server->secmech.sdesccmacaes->shash.flags = 0x0;

 	return 0;
 }

 static struct cifs_ses *
 smb2_find_smb_ses(struct smb2_hdr *smb2hdr, struct TCP_Server_Info *server)
 {
 	struct cifs_ses *ses;

 	spin_lock(&cifs_tcp_ses_lock);
 	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
 		if (ses->Suid != smb2hdr->SessionId)
 			continue;
 		spin_unlock(&cifs_tcp_ses_lock);
 		return ses;
 	}
 	spin_unlock(&cifs_tcp_ses_lock);

 	return NULL;
 }


 int
 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 {
 	int i, rc;
 	unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
 	unsigned char *sigptr = smb2_signature;
 	struct kvec *iov = rqst->rq_iov;
 	int n_vec = rqst->rq_nvec;
 	struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
 	struct cifs_ses *ses;

 	ses = smb2_find_smb_ses(smb2_pdu, server);
 	if (!ses) {
 		cifs_dbg(VFS, "%s: Could not find session\n", __func__);
 		return 0;
 	}

 	memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
 	memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE);

 	rc = smb2_crypto_shash_allocate(server);
 	if (rc) {
 		cifs_dbg(VFS, "%s: shah256 alloc failed\n", __func__);
 		return rc;
 	}

 	rc = crypto_shash_setkey(server->secmech.hmacsha256,
 		ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 		return rc;
 	}

 	rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not init sha256", __func__);
 		return rc;
 	}

 	for (i = 0; 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;
 		}
 		/*
 		 * 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 */
 			rc =
 			crypto_shash_update(
 				&server->secmech.sdeschmacsha256->shash,
 				iov[i].iov_base + 4, iov[i].iov_len - 4);
 		} else {
 			rc =
 			crypto_shash_update(
 				&server->secmech.sdeschmacsha256->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++) {
 		struct kvec p_iov;

 		cifs_rqst_page_to_kvec(rqst, i, &p_iov);
 		crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
 					p_iov.iov_base, p_iov.iov_len);
 		kunmap(rqst->rq_pages[i]);
 	}

 	rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
 				sigptr);
 	if (rc)
 		cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);

 	memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);

 	return rc;
 }

 int
 generate_smb3signingkey(struct cifs_ses *ses)
 {
 	unsigned char zero = 0x0;
 	__u8 i[4] = {0, 0, 0, 1};
 	__u8 L[4] = {0, 0, 0, 128};
 	int rc = 0;
 	unsigned char prfhash[SMB2_HMACSHA256_SIZE];
 	unsigned char *hashptr = prfhash;

 	memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
 	memset(ses->smb3signingkey, 0x0, SMB3_SIGNKEY_SIZE);

 	rc = smb3_crypto_shash_allocate(ses->server);
 	if (rc) {
 		cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
 		goto smb3signkey_ret;
 	}

 	rc = crypto_shash_setkey(ses->server->secmech.hmacsha256,
 		ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not set with session key\n", __func__);
 		goto smb3signkey_ret;
 	}

 	rc = crypto_shash_init(&ses->server->secmech.sdeschmacsha256->shash);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
 		goto smb3signkey_ret;
 	}

 	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 				i, 4);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not update with n\n", __func__);
 		goto smb3signkey_ret;
 	}

 	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 				"SMB2AESCMAC", 12);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not update with label\n", __func__);
 		goto smb3signkey_ret;
 	}

 	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 				&zero, 1);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not update with zero\n", __func__);
 		goto smb3signkey_ret;
 	}

 	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 				"SmbSign", 8);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not update with context\n", __func__);
 		goto smb3signkey_ret;
 	}

 	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 				L, 4);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not update with L\n", __func__);
 		goto smb3signkey_ret;
 	}

 	rc = crypto_shash_final(&ses->server->secmech.sdeschmacsha256->shash,
 				hashptr);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
 		goto smb3signkey_ret;
 	}

 	memcpy(ses->smb3signingkey, hashptr, SMB3_SIGNKEY_SIZE);

 smb3signkey_ret:
 	return rc;
 }

 int
 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 {
 	int i;
 	int rc = 0;
 	unsigned char smb3_signature[SMB2_CMACAES_SIZE];
 	unsigned char *sigptr = smb3_signature;
 	struct kvec *iov = rqst->rq_iov;
 	int n_vec = rqst->rq_nvec;
 	struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
 	struct cifs_ses *ses;

 	ses = smb2_find_smb_ses(smb2_pdu, server);
 	if (!ses) {
 		cifs_dbg(VFS, "%s: Could not find session\n", __func__);
 		return 0;
 	}

 	memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
 	memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE);

 	rc = crypto_shash_setkey(server->secmech.cmacaes,
 		ses->smb3signingkey, SMB2_CMACAES_SIZE);

 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
 		return rc;
 	}

 	/*
 	 * we already allocate sdesccmacaes when we init smb3 signing key,
 	 * so unlike smb2 case we do not have to check here if secmech are
 	 * initialized
 	 */
 	rc = crypto_shash_init(&server->secmech.sdesccmacaes->shash);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
 		return rc;
 	}

 	for (i = 0; i < n_vec; i++) {
 		if (iov[i].iov_len == 0)
 			continue;
 		if (iov[i].iov_base == NULL) {
 			cifs_dbg(VFS, "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 */
 			rc =
 			crypto_shash_update(
 				&server->secmech.sdesccmacaes->shash,
 				iov[i].iov_base + 4, iov[i].iov_len - 4);
 		} else {
 			rc =
 			crypto_shash_update(
 				&server->secmech.sdesccmacaes->shash,
 				iov[i].iov_base, iov[i].iov_len);
 		}
 		if (rc) {
 			cifs_dbg(VFS, "%s: Couldn't update cmac aes with payload\n",
 							__func__);
 			return rc;
 		}
 	}

 	/* now hash over the rq_pages array */
 	for (i = 0; i < rqst->rq_npages; i++) {
 		struct kvec p_iov;

 		cifs_rqst_page_to_kvec(rqst, i, &p_iov);
 		crypto_shash_update(&server->secmech.sdesccmacaes->shash,
 					p_iov.iov_base, p_iov.iov_len);
 		kunmap(rqst->rq_pages[i]);
 	}

 	rc = crypto_shash_final(&server->secmech.sdesccmacaes->shash,
 						sigptr);
 	if (rc)
 		cifs_dbg(VFS, "%s: Could not generate cmac aes\n", __func__);

 	memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);

 	return rc;
 }

 /* must be called with server->srv_mutex held */
 static int
 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 {
 	int rc = 0;
 	struct smb2_hdr *smb2_pdu = rqst->rq_iov[0].iov_base;

 	if (!(smb2_pdu->Flags & SMB2_FLAGS_SIGNED) ||
 	    server->tcpStatus == CifsNeedNegotiate)
 		return rc;

 	if (!server->session_estab) {
 		strncpy(smb2_pdu->Signature, "BSRSPYL", 8);
 		return rc;
 	}

 	rc = server->ops->calc_signature(rqst, server);

 	return rc;
 }

 int
 smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 {
 	unsigned int rc;
 	char server_response_sig[16];
 	struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)rqst->rq_iov[0].iov_base;

 	if ((smb2_pdu->Command == SMB2_NEGOTIATE) ||
 	    (smb2_pdu->Command == SMB2_SESSION_SETUP) ||
 	    (smb2_pdu->Command == SMB2_OPLOCK_BREAK) ||
 	    (!server->session_estab))
 		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(smb2_pdu->Signature, "BSRSPYL ", 8) == 0)
 		cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
 			 smb2_pdu->Command);

 	/*
 	 * Save off the origiginal signature so we can modify the smb and check
 	 * our calculated signature against what the server sent.
 	 */
 	memcpy(server_response_sig, smb2_pdu->Signature, SMB2_SIGNATURE_SIZE);

 	memset(smb2_pdu->Signature, 0, SMB2_SIGNATURE_SIZE);

 	mutex_lock(&server->srv_mutex);
 	rc = server->ops->calc_signature(rqst, server);
 	mutex_unlock(&server->srv_mutex);

 	if (rc)
 		return rc;

 	if (memcmp(server_response_sig, smb2_pdu->Signature,
 		   SMB2_SIGNATURE_SIZE))
 		return -EACCES;
 	else
 		return 0;
 }

 /*
  * Set message id for the request. Should be called after wait_for_free_request
  * and when srv_mutex is held.
  */
 static inline void
 smb2_seq_num_into_buf(struct TCP_Server_Info *server, struct smb2_hdr *hdr)
 {
 	unsigned int i, num = le16_to_cpu(hdr->CreditCharge);

 	hdr->MessageId = get_next_mid64(server);
 	/* skip message numbers according to CreditCharge field */
 	for (i = 1; i < num; i++)
 		get_next_mid(server);
 }

 static struct mid_q_entry *
 smb2_mid_entry_alloc(const struct smb2_hdr *smb_buffer,
 		     struct TCP_Server_Info *server)
 {
 	struct mid_q_entry *temp;

 	if (server == NULL) {
 		cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
 		return NULL;
 	}

 	temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
 	if (temp == NULL)
 		return temp;
 	else {
 		memset(temp, 0, sizeof(struct mid_q_entry));
 		temp->mid = le64_to_cpu(smb_buffer->MessageId);
 		temp->pid = current->pid;
 		temp->command = smb_buffer->Command;	/* Always LE */
 		temp->when_alloc = jiffies;
 		temp->server = server;

 		/*
 		 * The default is for the mid to be synchronous, so the
 		 * default callback just wakes up the current task.
 		 */
 		temp->callback = cifs_wake_up_task;
 		temp->callback_data = current;
 	}

 	atomic_inc(&midCount);
 	temp->mid_state = MID_REQUEST_ALLOCATED;
 	return temp;
 }

 static int
 smb2_get_mid_entry(struct cifs_ses *ses, struct smb2_hdr *buf,
 		   struct mid_q_entry **mid)
 {
 	if (ses->server->tcpStatus == CifsExiting)
 		return -ENOENT;

 	if (ses->server->tcpStatus == CifsNeedReconnect) {
 		cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
 		return -EAGAIN;
 	}

 	if (ses->status == CifsNew) {
 		if ((buf->Command != SMB2_SESSION_SETUP) &&
 		    (buf->Command != SMB2_NEGOTIATE))
 			return -EAGAIN;
 		/* else ok - we are setting up session */
 	}

 	if (ses->status == CifsExiting) {
 		if (buf->Command != SMB2_LOGOFF)
 			return -EAGAIN;
 		/* else ok - we are shutting down the session */
 	}

 	*mid = smb2_mid_entry_alloc(buf, ses->server);
 	if (*mid == NULL)
 		return -ENOMEM;
 	spin_lock(&GlobalMid_Lock);
 	list_add_tail(&(*mid)->qhead, &ses->server->pending_mid_q);
 	spin_unlock(&GlobalMid_Lock);
 	return 0;
 }

 int
 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 		   bool log_error)
 {
 	unsigned int len = get_rfc1002_length(mid->resp_buf);
 	struct kvec iov;
 	struct smb_rqst rqst = { .rq_iov = &iov,
 				 .rq_nvec = 1 };

 	iov.iov_base = (char *)mid->resp_buf;
 	iov.iov_len = get_rfc1002_length(mid->resp_buf) + 4;

 	dump_smb(mid->resp_buf, min_t(u32, 80, len));
 	/* convert the length into a more usable form */
 	if (len > 24 && server->sign) {
 		int rc;

 		rc = smb2_verify_signature(&rqst, server);
 		if (rc)
 			cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
 				 rc);
 	}

 	return map_smb2_to_linux_error(mid->resp_buf, log_error);
 }

 struct mid_q_entry *
 smb2_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
 {
 	int rc;
 	struct smb2_hdr *hdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
 	struct mid_q_entry *mid;

 	smb2_seq_num_into_buf(ses->server, hdr);

 	rc = smb2_get_mid_entry(ses, hdr, &mid);
 	if (rc)
 		return ERR_PTR(rc);
 	rc = smb2_sign_rqst(rqst, ses->server);
 	if (rc) {
 		cifs_delete_mid(mid);
 		return ERR_PTR(rc);
 	}
 	return mid;
 }

 struct mid_q_entry *
 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
 {
 	int rc;
 	struct smb2_hdr *hdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
 	struct mid_q_entry *mid;

 	smb2_seq_num_into_buf(server, hdr);

 	mid = smb2_mid_entry_alloc(hdr, server);
 	if (mid == NULL)
 		return ERR_PTR(-ENOMEM);

 	rc = smb2_sign_rqst(rqst, server);
 	if (rc) {
 		DeleteMidQEntry(mid);
 		return ERR_PTR(rc);
 	}

 	return mid;
 }
	/*
	* fs/cifs/smb2transport.c
	*
	* Copyright (C) International Business Machines Corp., 2002, 2011
	* Etersoft, 2012
	* Author(s): Steve French (sfrench@us.ibm.com)
	* Jeremy Allison (jra@samba.org) 2006
	* Pavel Shilovsky (pshilovsky@samba.org) 2012
	*
	* 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/list.h>
	#include <linux/wait.h>
	#include <linux/net.h>
	#include <linux/delay.h>
	#include <linux/uaccess.h>
	#include <asm/processor.h>
	#include <linux/mempool.h>
	#include <linux/highmem.h>
	#include "smb2pdu.h"
	#include "cifsglob.h"
	#include "cifsproto.h"
	#include "smb2proto.h"
	#include "cifs_debug.h"
	#include "smb2status.h"
	#include "smb2glob.h"

	static int
	smb2_crypto_shash_allocate(struct TCP_Server_Info *server)
	{
	int rc;
	unsigned int size;

	if (server->secmech.sdeschmacsha256 != NULL)
	return 0; /* already allocated */

	server->secmech.hmacsha256 = crypto_alloc_shash("hmac(sha256)", 0, 0);
	if (IS_ERR(server->secmech.hmacsha256)) {
	cifs_dbg(VFS, "could not allocate crypto hmacsha256\n");
	rc = PTR_ERR(server->secmech.hmacsha256);
	server->secmech.hmacsha256 = NULL;
	return rc;
	}

	size = sizeof(struct shash_desc) +
	crypto_shash_descsize(server->secmech.hmacsha256);
	server->secmech.sdeschmacsha256 = kmalloc(size, GFP_KERNEL);
	if (!server->secmech.sdeschmacsha256) {
	crypto_free_shash(server->secmech.hmacsha256);
	server->secmech.hmacsha256 = NULL;
	return -ENOMEM;
	}
	server->secmech.sdeschmacsha256->shash.tfm = server->secmech.hmacsha256;
	server->secmech.sdeschmacsha256->shash.flags = 0x0;

	return 0;
	}

	static int
	smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
	{
	unsigned int size;
	int rc;

	if (server->secmech.sdesccmacaes != NULL)
	return 0; /* already allocated */

	rc = smb2_crypto_shash_allocate(server);
	if (rc)
	return rc;

	server->secmech.cmacaes = crypto_alloc_shash("cmac(aes)", 0, 0);
	if (IS_ERR(server->secmech.cmacaes)) {
	cifs_dbg(VFS, "could not allocate crypto cmac-aes");
	kfree(server->secmech.sdeschmacsha256);
	server->secmech.sdeschmacsha256 = NULL;
	crypto_free_shash(server->secmech.hmacsha256);
	server->secmech.hmacsha256 = NULL;
	rc = PTR_ERR(server->secmech.cmacaes);
	server->secmech.cmacaes = NULL;
	return rc;
	}

	size = sizeof(struct shash_desc) +
	crypto_shash_descsize(server->secmech.cmacaes);
	server->secmech.sdesccmacaes = kmalloc(size, GFP_KERNEL);
	if (!server->secmech.sdesccmacaes) {
	cifs_dbg(VFS, "%s: Can't alloc cmacaes\n", __func__);
	kfree(server->secmech.sdeschmacsha256);
	server->secmech.sdeschmacsha256 = NULL;
	crypto_free_shash(server->secmech.hmacsha256);
	crypto_free_shash(server->secmech.cmacaes);
	server->secmech.hmacsha256 = NULL;
	server->secmech.cmacaes = NULL;
	return -ENOMEM;
	}
	server->secmech.sdesccmacaes->shash.tfm = server->secmech.cmacaes;
	server->secmech.sdesccmacaes->shash.flags = 0x0;

	return 0;
	}

	static struct cifs_ses *
	smb2_find_smb_ses(struct smb2_hdr smb2hdr, struct TCP_Server_Info server)
	{
	struct cifs_ses *ses;

	spin_lock(&cifs_tcp_ses_lock);
	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
	if (ses->Suid != smb2hdr->SessionId)
	continue;
	spin_unlock(&cifs_tcp_ses_lock);
	return ses;
	}
	spin_unlock(&cifs_tcp_ses_lock);

	return NULL;
	}


	int
	smb2_calc_signature(struct smb_rqst rqst, struct TCP_Server_Info server)
	{
	int i, rc;
	unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
	unsigned char *sigptr = smb2_signature;
	struct kvec *iov = rqst->rq_iov;
	int n_vec = rqst->rq_nvec;
	struct smb2_hdr smb2_pdu = (struct smb2_hdr )iov[0].iov_base;
	struct cifs_ses *ses;

	ses = smb2_find_smb_ses(smb2_pdu, server);
	if (!ses) {
	cifs_dbg(VFS, "%s: Could not find session\n", __func__);
	return 0;
	}

	memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
	memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE);

	rc = smb2_crypto_shash_allocate(server);
	if (rc) {
	cifs_dbg(VFS, "%s: shah256 alloc failed\n", __func__);
	return rc;
	}

	rc = crypto_shash_setkey(server->secmech.hmacsha256,
	ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
	if (rc) {
	cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
	return rc;
	}

	rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
	if (rc) {
	cifs_dbg(VFS, "%s: Could not init sha256", __func__);
	return rc;
	}

	for (i = 0; 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;
	}
	/*
	* 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 */
	rc =
	crypto_shash_update(
	&server->secmech.sdeschmacsha256->shash,
	iov[i].iov_base + 4, iov[i].iov_len - 4);
	} else {
	rc =
	crypto_shash_update(
	&server->secmech.sdeschmacsha256->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++) {
	struct kvec p_iov;

	cifs_rqst_page_to_kvec(rqst, i, &p_iov);
	crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
	p_iov.iov_base, p_iov.iov_len);
	kunmap(rqst->rq_pages[i]);
	}

	rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
	sigptr);
	if (rc)
	cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);

	memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);

	return rc;
	}

	int
	generate_smb3signingkey(struct cifs_ses *ses)
	{
	unsigned char zero = 0x0;
	__u8 i[4] = {0, 0, 0, 1};
	__u8 L[4] = {0, 0, 0, 128};
	int rc = 0;
	unsigned char prfhash[SMB2_HMACSHA256_SIZE];
	unsigned char *hashptr = prfhash;

	memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
	memset(ses->smb3signingkey, 0x0, SMB3_SIGNKEY_SIZE);

	rc = smb3_crypto_shash_allocate(ses->server);
	if (rc) {
	cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
	goto smb3signkey_ret;
	}

	rc = crypto_shash_setkey(ses->server->secmech.hmacsha256,
	ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
	if (rc) {
	cifs_dbg(VFS, "%s: Could not set with session key\n", __func__);
	goto smb3signkey_ret;
	}

	rc = crypto_shash_init(&ses->server->secmech.sdeschmacsha256->shash);
	if (rc) {
	cifs_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
	goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
	i, 4);
	if (rc) {
	cifs_dbg(VFS, "%s: Could not update with n\n", __func__);
	goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
	"SMB2AESCMAC", 12);
	if (rc) {
	cifs_dbg(VFS, "%s: Could not update with label\n", __func__);
	goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
	&zero, 1);
	if (rc) {
	cifs_dbg(VFS, "%s: Could not update with zero\n", __func__);
	goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
	"SmbSign", 8);
	if (rc) {
	cifs_dbg(VFS, "%s: Could not update with context\n", __func__);
	goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
	L, 4);
	if (rc) {
	cifs_dbg(VFS, "%s: Could not update with L\n", __func__);
	goto smb3signkey_ret;
	}

	rc = crypto_shash_final(&ses->server->secmech.sdeschmacsha256->shash,
	hashptr);
	if (rc) {
	cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
	goto smb3signkey_ret;
	}

	memcpy(ses->smb3signingkey, hashptr, SMB3_SIGNKEY_SIZE);

	smb3signkey_ret:
	return rc;
	}

	int
	smb3_calc_signature(struct smb_rqst rqst, struct TCP_Server_Info server)
	{
	int i;
	int rc = 0;
	unsigned char smb3_signature[SMB2_CMACAES_SIZE];
	unsigned char *sigptr = smb3_signature;
	struct kvec *iov = rqst->rq_iov;
	int n_vec = rqst->rq_nvec;
	struct smb2_hdr smb2_pdu = (struct smb2_hdr )iov[0].iov_base;
	struct cifs_ses *ses;

	ses = smb2_find_smb_ses(smb2_pdu, server);
	if (!ses) {
	cifs_dbg(VFS, "%s: Could not find session\n", __func__);
	return 0;
	}

	memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
	memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE);

	rc = crypto_shash_setkey(server->secmech.cmacaes,
	ses->smb3signingkey, SMB2_CMACAES_SIZE);

	if (rc) {
	cifs_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
	return rc;
	}

	/*
	* we already allocate sdesccmacaes when we init smb3 signing key,
	* so unlike smb2 case we do not have to check here if secmech are
	* initialized
	*/
	rc = crypto_shash_init(&server->secmech.sdesccmacaes->shash);
	if (rc) {
	cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
	return rc;
	}

	for (i = 0; i < n_vec; i++) {
	if (iov[i].iov_len == 0)
	continue;
	if (iov[i].iov_base == NULL) {
	cifs_dbg(VFS, "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 */
	rc =
	crypto_shash_update(
	&server->secmech.sdesccmacaes->shash,
	iov[i].iov_base + 4, iov[i].iov_len - 4);
	} else {
	rc =
	crypto_shash_update(
	&server->secmech.sdesccmacaes->shash,
	iov[i].iov_base, iov[i].iov_len);
	}
	if (rc) {
	cifs_dbg(VFS, "%s: Couldn't update cmac aes with payload\n",
	__func__);
	return rc;
	}
	}

	/* now hash over the rq_pages array */
	for (i = 0; i < rqst->rq_npages; i++) {
	struct kvec p_iov;

	cifs_rqst_page_to_kvec(rqst, i, &p_iov);
	crypto_shash_update(&server->secmech.sdesccmacaes->shash,
	p_iov.iov_base, p_iov.iov_len);
	kunmap(rqst->rq_pages[i]);
	}

	rc = crypto_shash_final(&server->secmech.sdesccmacaes->shash,
	sigptr);
	if (rc)
	cifs_dbg(VFS, "%s: Could not generate cmac aes\n", __func__);

	memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);

	return rc;
	}

	/* must be called with server->srv_mutex held */
	static int
	smb2_sign_rqst(struct smb_rqst rqst, struct TCP_Server_Info server)
	{
	int rc = 0;
	struct smb2_hdr *smb2_pdu = rqst->rq_iov[0].iov_base;

	if (!(smb2_pdu->Flags & SMB2_FLAGS_SIGNED) \|\|
	server->tcpStatus == CifsNeedNegotiate)
	return rc;

	if (!server->session_estab) {
	strncpy(smb2_pdu->Signature, "BSRSPYL", 8);
	return rc;
	}

	rc = server->ops->calc_signature(rqst, server);

	return rc;
	}

	int
	smb2_verify_signature(struct smb_rqst rqst, struct TCP_Server_Info server)
	{
	unsigned int rc;
	char server_response_sig[16];
	struct smb2_hdr smb2_pdu = (struct smb2_hdr )rqst->rq_iov[0].iov_base;

	if ((smb2_pdu->Command == SMB2_NEGOTIATE) \|\|
	(smb2_pdu->Command == SMB2_SESSION_SETUP) \|\|
	(smb2_pdu->Command == SMB2_OPLOCK_BREAK) \|\|
	(!server->session_estab))
	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(smb2_pdu->Signature, "BSRSPYL ", 8) == 0)
	cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
	smb2_pdu->Command);

	/*
	* Save off the origiginal signature so we can modify the smb and check
	* our calculated signature against what the server sent.
	*/
	memcpy(server_response_sig, smb2_pdu->Signature, SMB2_SIGNATURE_SIZE);

	memset(smb2_pdu->Signature, 0, SMB2_SIGNATURE_SIZE);

	mutex_lock(&server->srv_mutex);
	rc = server->ops->calc_signature(rqst, server);
	mutex_unlock(&server->srv_mutex);

	if (rc)
	return rc;

	if (memcmp(server_response_sig, smb2_pdu->Signature,
	SMB2_SIGNATURE_SIZE))
	return -EACCES;
	else
	return 0;
	}

	/*
	* Set message id for the request. Should be called after wait_for_free_request
	* and when srv_mutex is held.
	*/
	static inline void
	smb2_seq_num_into_buf(struct TCP_Server_Info server, struct smb2_hdr hdr)
	{
	unsigned int i, num = le16_to_cpu(hdr->CreditCharge);

	hdr->MessageId = get_next_mid64(server);
	/* skip message numbers according to CreditCharge field */
	for (i = 1; i < num; i++)
	get_next_mid(server);
	}

	static struct mid_q_entry *
	smb2_mid_entry_alloc(const struct smb2_hdr *smb_buffer,
	struct TCP_Server_Info *server)
	{
	struct mid_q_entry *temp;

	if (server == NULL) {
	cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
	return NULL;
	}

	temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
	if (temp == NULL)
	return temp;
	else {
	memset(temp, 0, sizeof(struct mid_q_entry));
	temp->mid = le64_to_cpu(smb_buffer->MessageId);
	temp->pid = current->pid;
	temp->command = smb_buffer->Command; /* Always LE */
	temp->when_alloc = jiffies;
	temp->server = server;

	/*
	* The default is for the mid to be synchronous, so the
	* default callback just wakes up the current task.
	*/
	temp->callback = cifs_wake_up_task;
	temp->callback_data = current;
	}

	atomic_inc(&midCount);
	temp->mid_state = MID_REQUEST_ALLOCATED;
	return temp;
	}

	static int
	smb2_get_mid_entry(struct cifs_ses ses, struct smb2_hdr buf,
	struct mid_q_entry **mid)
	{
	if (ses->server->tcpStatus == CifsExiting)
	return -ENOENT;

	if (ses->server->tcpStatus == CifsNeedReconnect) {
	cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
	return -EAGAIN;
	}

	if (ses->status == CifsNew) {
	if ((buf->Command != SMB2_SESSION_SETUP) &&
	(buf->Command != SMB2_NEGOTIATE))
	return -EAGAIN;
	/* else ok - we are setting up session */
	}

	if (ses->status == CifsExiting) {
	if (buf->Command != SMB2_LOGOFF)
	return -EAGAIN;
	/* else ok - we are shutting down the session */
	}

	*mid = smb2_mid_entry_alloc(buf, ses->server);
	if (*mid == NULL)
	return -ENOMEM;
	spin_lock(&GlobalMid_Lock);
	list_add_tail(&(*mid)->qhead, &ses->server->pending_mid_q);
	spin_unlock(&GlobalMid_Lock);
	return 0;
	}

	int
	smb2_check_receive(struct mid_q_entry mid, struct TCP_Server_Info server,
	bool log_error)
	{
	unsigned int len = get_rfc1002_length(mid->resp_buf);
	struct kvec iov;
	struct smb_rqst rqst = { .rq_iov = &iov,
	.rq_nvec = 1 };

	iov.iov_base = (char *)mid->resp_buf;
	iov.iov_len = get_rfc1002_length(mid->resp_buf) + 4;

	dump_smb(mid->resp_buf, min_t(u32, 80, len));
	/* convert the length into a more usable form */
	if (len > 24 && server->sign) {
	int rc;

	rc = smb2_verify_signature(&rqst, server);
	if (rc)
	cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
	rc);
	}

	return map_smb2_to_linux_error(mid->resp_buf, log_error);
	}

	struct mid_q_entry *
	smb2_setup_request(struct cifs_ses ses, struct smb_rqst rqst)
	{
	int rc;
	struct smb2_hdr hdr = (struct smb2_hdr )rqst->rq_iov[0].iov_base;
	struct mid_q_entry *mid;

	smb2_seq_num_into_buf(ses->server, hdr);

	rc = smb2_get_mid_entry(ses, hdr, &mid);
	if (rc)
	return ERR_PTR(rc);
	rc = smb2_sign_rqst(rqst, ses->server);
	if (rc) {
	cifs_delete_mid(mid);
	return ERR_PTR(rc);
	}
	return mid;
	}

	struct mid_q_entry *
	smb2_setup_async_request(struct TCP_Server_Info server, struct smb_rqst rqst)
	{
	int rc;
	struct smb2_hdr hdr = (struct smb2_hdr )rqst->rq_iov[0].iov_base;
	struct mid_q_entry *mid;

	smb2_seq_num_into_buf(server, hdr);

	mid = smb2_mid_entry_alloc(hdr, server);
	if (mid == NULL)
	return ERR_PTR(-ENOMEM);

	rc = smb2_sign_rqst(rqst, server);
	if (rc) {
	DeleteMidQEntry(mid);
	return ERR_PTR(rc);
	}

	return mid;
	}