[PATCH] fs/smb: using crypto lib instead cifs_arc4

John Sanpe
2023-10-22T18:39:32Z

Replace internal logic with an independent arc4 library.

Signed-off-by: John Sanpe <sanpeqf@gmail.com>
---
fs/smb/Kconfig | 1 +
fs/smb/client/cifsencrypt.c | 7 ++--
fs/smb/common/Makefile | 1 -
fs/smb/common/arc4.h | 23 ------------
fs/smb/common/cifs_arc4.c | 74 -------------------------------------
fs/smb/server/auth.c | 6 +--
6 files changed, 7 insertions(+), 105 deletions(-)
delete mode 100644 fs/smb/common/arc4.h
delete mode 100644 fs/smb/common/cifs_arc4.c

diff --git a/fs/smb/Kconfig b/fs/smb/Kconfig
index ef425789fa6a..65e5a437898b 100644
--- a/fs/smb/Kconfig
+++ b/fs/smb/Kconfig
@@ -7,5 +7,6 @@ source "fs/smb/server/Kconfig"

config SMBFS
tristate
+ select CRYPTO_LIB_ARC4
default y if CIFS=y || SMB_SERVER=y
default m if CIFS=m || SMB_SERVER=m
diff --git a/fs/smb/client/cifsencrypt.c b/fs/smb/client/cifsencrypt.c
index ef4c2e3c9fa6..d8754c406b5f 100644
--- a/fs/smb/client/cifsencrypt.c
+++ b/fs/smb/client/cifsencrypt.c
@@ -21,7 +21,7 @@
#include <linux/random.h>
#include <linux/highmem.h>
#include <linux/fips.h>
-#include "../common/arc4.h"
+#include <crypto/arc4.h>
#include <crypto/aead.h>

/*
@@ -826,9 +826,8 @@ calc_seckey(struct cifs_ses *ses)
return -ENOMEM;
}

- cifs_arc4_setkey(ctx_arc4, ses->auth_key.response, CIFS_SESS_KEY_SIZE);
- cifs_arc4_crypt(ctx_arc4, ses->ntlmssp->ciphertext, sec_key,
- CIFS_CPHTXT_SIZE);
+ arc4_setkey(ctx_arc4, ses->auth_key.response, CIFS_SESS_KEY_SIZE);
+ arc4_crypt(ctx_arc4, ses->ntlmssp->ciphertext, sec_key, CIFS_CPHTXT_SIZE);

/* make secondary_key/nonce as session key */
memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE);
diff --git a/fs/smb/common/Makefile b/fs/smb/common/Makefile
index c66dbbc1469c..9e0730a385fb 100644
--- a/fs/smb/common/Makefile
+++ b/fs/smb/common/Makefile
@@ -3,5 +3,4 @@
# Makefile for Linux filesystem routines that are shared by client and server.
#

-obj-$(CONFIG_SMBFS) += cifs_arc4.o
obj-$(CONFIG_SMBFS) += cifs_md4.o
diff --git a/fs/smb/common/arc4.h b/fs/smb/common/arc4.h
deleted file mode 100644
index 12e71ec033a1..000000000000
--- a/fs/smb/common/arc4.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
-/*
- * Common values for ARC4 Cipher Algorithm
- */
-
-#ifndef _CRYPTO_ARC4_H
-#define _CRYPTO_ARC4_H
-
-#include <linux/types.h>
-
-#define ARC4_MIN_KEY_SIZE 1
-#define ARC4_MAX_KEY_SIZE 256
-#define ARC4_BLOCK_SIZE 1
-
-struct arc4_ctx {
- u32 S[256];
- u32 x, y;
-};
-
-int cifs_arc4_setkey(struct arc4_ctx *ctx, const u8 *in_key, unsigned int key_len);
-void cifs_arc4_crypt(struct arc4_ctx *ctx, u8 *out, const u8 *in, unsigned int len);
-
-#endif /* _CRYPTO_ARC4_H */
diff --git a/fs/smb/common/cifs_arc4.c b/fs/smb/common/cifs_arc4.c
deleted file mode 100644
index 043e4cb839fa..000000000000
--- a/fs/smb/common/cifs_arc4.c
+++ /dev/null
@@ -1,74 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * Cryptographic API
- *
- * ARC4 Cipher Algorithm
- *
- * Jon Oberheide <jon@oberheide.org>
- */
-
-#include <linux/module.h>
-#include "arc4.h"
-
-MODULE_LICENSE("GPL");
-
-int cifs_arc4_setkey(struct arc4_ctx *ctx, const u8 *in_key, unsigned int key_len)
-{
- int i, j = 0, k = 0;
-
- ctx->x = 1;
- ctx->y = 0;
-
- for (i = 0; i < 256; i++)
- ctx->S[i] = i;
-
- for (i = 0; i < 256; i++) {
- u32 a = ctx->S[i];
-
- j = (j + in_key[k] + a) & 0xff;
- ctx->S[i] = ctx->S[j];
- ctx->S[j] = a;
- if (++k >= key_len)
- k = 0;
- }
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(cifs_arc4_setkey);
-
-void cifs_arc4_crypt(struct arc4_ctx *ctx, u8 *out, const u8 *in, unsigned int len)
-{
- u32 *const S = ctx->S;
- u32 x, y, a, b;
- u32 ty, ta, tb;
-
- if (len == 0)
- return;
-
- x = ctx->x;
- y = ctx->y;
-
- a = S[x];
- y = (y + a) & 0xff;
- b = S[y];
-
- do {
- S[y] = a;
- a = (a + b) & 0xff;
- S[x] = b;
- x = (x + 1) & 0xff;
- ta = S[x];
- ty = (y + ta) & 0xff;
- tb = S[ty];
- *out++ = *in++ ^ S[a];
- if (--len == 0)
- break;
- y = ty;
- a = ta;
- b = tb;
- } while (true);
-
- ctx->x = x;
- ctx->y = y;
-}
-EXPORT_SYMBOL_GPL(cifs_arc4_crypt);
diff --git a/fs/smb/server/auth.c b/fs/smb/server/auth.c
index 229a6527870d..5640196b313f 100644
--- a/fs/smb/server/auth.c
+++ b/fs/smb/server/auth.c
@@ -29,7 +29,7 @@
#include "mgmt/user_config.h"
#include "crypto_ctx.h"
#include "transport_ipc.h"
-#include "../common/arc4.h"
+#include <crypto/arc4.h>

/*
* Fixed format data defining GSS header and fixed string
@@ -362,9 +362,9 @@ int ksmbd_decode_ntlmssp_auth_blob(struct authenticate_message *authblob,
if (!ctx_arc4)
return -ENOMEM;

- cifs_arc4_setkey(ctx_arc4, sess->sess_key,
+ arc4_setkey(ctx_arc4, sess->sess_key,
SMB2_NTLMV2_SESSKEY_SIZE);
- cifs_arc4_crypt(ctx_arc4, sess->sess_key,
+ arc4_crypt(ctx_arc4, sess->sess_key,
(char *)authblob + sess_key_off, sess_key_len);
kfree_sensitive(ctx_arc4);
}
--
2.41.0