From 71c02863246167b3d1639b8278681ca8ebedcb4e Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Thu, 19 Aug 2021 20:34:59 +1000 Subject: [PATCH] cifs: fork arc4 and create a separate module for it for cifs and other users We can not drop ARC4 and basically destroy CIFS connectivity for almost all CIFS users so create a new forked ARC4 module that CIFS and other subsystems that have a hard dependency on ARC4 can use. Signed-off-by: Ronnie Sahlberg Signed-off-by: Steve French --- fs/Kconfig | 7 +++ fs/Makefile | 1 + fs/cifs/Kconfig | 1 - fs/cifs/cifsencrypt.c | 8 ++-- fs/cifs_common/Makefile | 6 +++ fs/cifs_common/arc4.h | 23 ++++++++++ fs/cifs_common/cifs_arc4.c | 87 ++++++++++++++++++++++++++++++++++++++ 7 files changed, 128 insertions(+), 5 deletions(-) create mode 100644 fs/cifs_common/Makefile create mode 100644 fs/cifs_common/arc4.h create mode 100644 fs/cifs_common/cifs_arc4.c diff --git a/fs/Kconfig b/fs/Kconfig index a7749c126b8e..6d719f2c5828 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -358,7 +358,14 @@ config NFS_V4_2_SSC_HELPER source "net/sunrpc/Kconfig" source "fs/ceph/Kconfig" + source "fs/cifs/Kconfig" + +config CIFS_COMMON + tristate + default y if CIFS=y + default m if CIFS=m + source "fs/coda/Kconfig" source "fs/afs/Kconfig" source "fs/9p/Kconfig" diff --git a/fs/Makefile b/fs/Makefile index f98f3e691c37..77b0e79c8b4f 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -96,6 +96,7 @@ obj-$(CONFIG_LOCKD) += lockd/ obj-$(CONFIG_NLS) += nls/ obj-$(CONFIG_UNICODE) += unicode/ obj-$(CONFIG_SYSV_FS) += sysv/ +obj-$(CONFIG_CIFS_COMMON) += cifs_common/ obj-$(CONFIG_CIFS) += cifs/ obj-$(CONFIG_HPFS_FS) += hpfs/ obj-$(CONFIG_NTFS_FS) += ntfs/ diff --git a/fs/cifs/Kconfig b/fs/cifs/Kconfig index 2e8b132efdbc..aa4457d72392 100644 --- a/fs/cifs/Kconfig +++ b/fs/cifs/Kconfig @@ -10,7 +10,6 @@ config CIFS select CRYPTO_SHA512 select CRYPTO_CMAC select CRYPTO_HMAC - select CRYPTO_LIB_ARC4 select CRYPTO_AEAD2 select CRYPTO_CCM select CRYPTO_GCM diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c index 7680e0a9bea3..6679e07e533e 100644 --- a/fs/cifs/cifsencrypt.c +++ b/fs/cifs/cifsencrypt.c @@ -22,7 +22,7 @@ #include #include #include -#include +#include "../cifs_common/arc4.h" #include int __cifs_calc_signature(struct smb_rqst *rqst, @@ -699,9 +699,9 @@ calc_seckey(struct cifs_ses *ses) return -ENOMEM; } - arc4_setkey(ctx_arc4, ses->auth_key.response, CIFS_SESS_KEY_SIZE); - arc4_crypt(ctx_arc4, ses->ntlmssp->ciphertext, sec_key, - CIFS_CPHTXT_SIZE); + 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); /* make secondary_key/nonce as session key */ memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE); diff --git a/fs/cifs_common/Makefile b/fs/cifs_common/Makefile new file mode 100644 index 000000000000..2fc9b40345c4 --- /dev/null +++ b/fs/cifs_common/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Makefile for Linux filesystem routines that are shared by client and server. +# + +obj-$(CONFIG_CIFS_COMMON) += cifs_arc4.o diff --git a/fs/cifs_common/arc4.h b/fs/cifs_common/arc4.h new file mode 100644 index 000000000000..12e71ec033a1 --- /dev/null +++ b/fs/cifs_common/arc4.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Common values for ARC4 Cipher Algorithm + */ + +#ifndef _CRYPTO_ARC4_H +#define _CRYPTO_ARC4_H + +#include + +#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/cifs_common/cifs_arc4.c b/fs/cifs_common/cifs_arc4.c new file mode 100644 index 000000000000..b964cc682944 --- /dev/null +++ b/fs/cifs_common/cifs_arc4.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Cryptographic API + * + * ARC4 Cipher Algorithm + * + * Jon Oberheide + */ + +#include +#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); + +static int __init +init_cifs_common(void) +{ + return 0; +} +static void __init +exit_cifs_common(void) +{ +} + +module_init(init_cifs_common) +module_exit(exit_cifs_common)