Commit 220d83b5 authored by Enzo Matsumiya's avatar Enzo Matsumiya Committed by Steve French
Browse files

smb: client: make SHA-512 TFM ephemeral 



The SHA-512 shash TFM is used only briefly during Session Setup stage,
when computing SMB 3.1.1 preauth hash.

There's no need to keep it allocated in servers' secmech the whole time,
so keep its lifetime inside smb311_update_preauth_hash().

This also makes smb311_crypto_shash_allocate() redundant, so expose
smb3_crypto_shash_allocate() and use that.

Signed-off-by: default avatarEnzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent db44ca9f

fs/smb/client/cifsencrypt.c

+0 −1
Original line number Diff line number Diff line
@@ -700,7 +700,6 @@ cifs_crypto_secmech_release(struct TCP_Server_Info *server) 
	cifs_free_hash(&server->secmech.aes_cmac);

	cifs_free_hash(&server->secmech.hmacsha256);

	cifs_free_hash(&server->secmech.md5);

	cifs_free_hash(&server->secmech.sha512);



	if (!SERVER_IS_CHAN(server)) {

		if (server->secmech.enc) {

fs/smb/client/cifsglob.h

+0 −1
Original line number Diff line number Diff line
@@ -180,7 +180,6 @@ struct session_key { 
struct cifs_secmech {

	struct shash_desc *md5; /* md5 hash function, for CIFS/SMB1 signatures */

	struct shash_desc *hmacsha256; /* hmac-sha256 hash function, for SMB2 signatures */

	struct shash_desc *sha512; /* sha512 hash function, for SMB3.1.1 preauth hash */

	struct shash_desc *aes_cmac; /* block-cipher based MAC function, for SMB3 signatures */



	struct crypto_aead *enc; /* smb3 encryption AEAD TFM (AES-CCM and AES-GCM) */

fs/smb/client/sess.c

+1 −1
Original line number Diff line number Diff line
@@ -624,7 +624,7 @@ cifs_ses_add_channel(struct cifs_ses *ses, 
	 * to sign packets before we generate the channel signing key

	 * (we sign with the session key)

	 */

	rc = smb311_crypto_shash_allocate(chan->server);

	rc = smb3_crypto_shash_allocate(chan->server);

	if (rc) {

		cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);

		mutex_unlock(&ses->session_mutex);

fs/smb/client/smb2misc.c

+14 −14
Original line number Diff line number Diff line
@@ -906,41 +906,41 @@ smb311_update_preauth_hash(struct cifs_ses *ses, struct TCP_Server_Info *server, 
		|| (hdr->Status !=

		    cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))))

		return 0;



ok:

	rc = smb311_crypto_shash_allocate(server);

	if (rc)

	rc = cifs_alloc_hash("sha512", &sha512);

	if (rc) {

		cifs_dbg(VFS, "%s: Could not allocate SHA512 shash, rc=%d\n", __func__, rc);

		return rc;

	}



	sha512 = server->secmech.sha512;

	rc = crypto_shash_init(sha512);

	if (rc) {

		cifs_dbg(VFS, "%s: Could not init sha512 shash\n", __func__);

		return rc;

		cifs_dbg(VFS, "%s: Could not init SHA512 shash, rc=%d\n", __func__, rc);

		goto err_free;

	}



	rc = crypto_shash_update(sha512, ses->preauth_sha_hash,

				 SMB2_PREAUTH_HASH_SIZE);

	if (rc) {

		cifs_dbg(VFS, "%s: Could not update sha512 shash\n", __func__);

		return rc;

		cifs_dbg(VFS, "%s: Could not update SHA512 shash, rc=%d\n", __func__, rc);

		goto err_free;

	}



	for (i = 0; i < nvec; i++) {

		rc = crypto_shash_update(sha512, iov[i].iov_base, iov[i].iov_len);

		if (rc) {

			cifs_dbg(VFS, "%s: Could not update sha512 shash\n",

				 __func__);

			return rc;

			cifs_dbg(VFS, "%s: Could not update SHA512 shash, rc=%d\n", __func__, rc);

			goto err_free;

		}

	}



	rc = crypto_shash_final(sha512, ses->preauth_sha_hash);

	if (rc) {

		cifs_dbg(VFS, "%s: Could not finalize sha512 shash\n",

			 __func__);

		return rc;

		cifs_dbg(VFS, "%s: Could not finalize SHA12 shash, rc=%d\n", __func__, rc);

		goto err_free;

	}

err_free:

	cifs_free_hash(&sha512);



	return 0;

}

fs/smb/client/smb2proto.h

+1 −1
Original line number Diff line number Diff line
@@ -291,7 +291,7 @@ extern int smb2_validate_and_copy_iov(unsigned int offset, 
extern void smb2_copy_fs_info_to_kstatfs(

	 struct smb2_fs_full_size_info *pfs_inf,

	 struct kstatfs *kst);

extern int smb311_crypto_shash_allocate(struct TCP_Server_Info *server);

extern int smb3_crypto_shash_allocate(struct TCP_Server_Info *server);

extern int smb311_update_preauth_hash(struct cifs_ses *ses,

				      struct TCP_Server_Info *server,

				      struct kvec *iov, int nvec);