[PATCH] Delete cryptoloop

James Morris
2004-07-21T20:18:30Z

This patch deletes cryptoloop, which is buggy, unmaintained, and
reportedly has mutliple security weaknesses. Dropping cryptoloop should
also help dm-crypt receive more testing and review.

I haven't updated the defconfigs, is this something for arch maintainers
to manage?

drivers/block/Kconfig | 22 ---
drivers/block/Makefile | 1
drivers/block/cryptoloop.c | 268
---------------------------------------------
3 files changed, 2 insertions(+), 289 deletions(-)

diff -urN a/drivers/block/cryptoloop.c b/drivers/block/cryptoloop.c
--- a/drivers/block/cryptoloop.c 2004-07-21 15:40:46.000000000 -0400
+++ b/drivers/block/cryptoloop.c 1969-12-31 19:00:00.000000000 -0500
@@ -1,268 +0,0 @@
-/*
- Linux loop encryption enabling module
-
- Copyright (C) 2002 Herbert Valerio Riedel <hvr@gnu.org>
- Copyright (C) 2003 Fruhwirth Clemens <clemens@endorphin.org>
-
- This module is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- This module 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 General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this module; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-#include <linux/module.h>
-
-#include <linux/init.h>
-#include <linux/string.h>
-#include <linux/crypto.h>
-#include <linux/blkdev.h>
-#include <linux/loop.h>
-#include <asm/semaphore.h>
-#include <asm/uaccess.h>
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("loop blockdevice transferfunction adaptor / CryptoAPI");
-MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
-
-#define LOOP_IV_SECTOR_BITS 9
-#define LOOP_IV_SECTOR_SIZE (1 << LOOP_IV_SECTOR_BITS)
-
-static int
-cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info)
-{
- int err = -EINVAL;
- char cms[LO_NAME_SIZE]; /* cipher-mode string */
- char *cipher;
- char *mode;
- char *cmsp = cms; /* c-m string pointer */
- struct crypto_tfm *tfm = NULL;
-
- /* encryption breaks for non sector aligned offsets */
-
- if (info->lo_offset % LOOP_IV_SECTOR_SIZE)
- goto out;
-
- strncpy(cms, info->lo_crypt_name, LO_NAME_SIZE);
- cms[LO_NAME_SIZE - 1] = 0;
- cipher = strsep(&cmsp, "-");
- mode = strsep(&cmsp, "-");
-
- if (mode == NULL || strcmp(mode, "cbc") == 0)
- tfm = crypto_alloc_tfm(cipher, CRYPTO_TFM_MODE_CBC);
- else if (strcmp(mode, "ecb") == 0)
- tfm = crypto_alloc_tfm(cipher, CRYPTO_TFM_MODE_ECB);
- if (tfm == NULL)
- return -EINVAL;
-
- err = tfm->crt_u.cipher.cit_setkey(tfm, info->lo_encrypt_key,
- info->lo_encrypt_key_size);
-
- if (err != 0)
- goto out_free_tfm;
-
- lo->key_data = tfm;
- return 0;
-
- out_free_tfm:
- crypto_free_tfm(tfm);
-
- out:
- return err;
-}
-
-
-typedef int (*encdec_ecb_t)(struct crypto_tfm *tfm,
- struct scatterlist *sg_out,
- struct scatterlist *sg_in,
- unsigned int nsg);
-
-
-static int
-cryptoloop_transfer_ecb(struct loop_device *lo, int cmd,
- struct page *raw_page, unsigned raw_off,
- struct page *loop_page, unsigned loop_off,
- int size, sector_t IV)
-{
- struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data;
- struct scatterlist sg_out = { NULL, };
- struct scatterlist sg_in = { NULL, };
-
- encdec_ecb_t encdecfunc;
- struct page *in_page, *out_page;
- unsigned in_offs, out_offs;
-
- if (cmd == READ) {
- in_page = raw_page;
- in_offs = raw_off;
- out_page = loop_page;
- out_offs = loop_off;
- encdecfunc = tfm->crt_u.cipher.cit_decrypt;
- } else {
- in_page = loop_page;
- in_offs = loop_off;
- out_page = raw_page;
- out_offs = raw_off;
- encdecfunc = tfm->crt_u.cipher.cit_encrypt;
- }
-
- while (size > 0) {
- const int sz = min(size, LOOP_IV_SECTOR_SIZE);
-
- sg_in.page = in_page;
- sg_in.offset = in_offs;
- sg_in.length = sz;
-
- sg_out.page = out_page;
- sg_out.offset = out_offs;
- sg_out.length = sz;
-
- encdecfunc(tfm, &sg_out, &sg_in, sz);
-
- size -= sz;
- in_offs += sz;
- out_offs += sz;
- }
-
- return 0;
-}
-
-typedef int (*encdec_cbc_t)(struct crypto_tfm *tfm,
- struct scatterlist *sg_out,
- struct scatterlist *sg_in,
- unsigned int nsg, u8 *iv);
-
-static int
-cryptoloop_transfer_cbc(struct loop_device *lo, int cmd,
- struct page *raw_page, unsigned raw_off,
- struct page *loop_page, unsigned loop_off,
- int size, sector_t IV)
-{
- struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data;
- struct scatterlist sg_out = { NULL, };
- struct scatterlist sg_in = { NULL, };
-
- encdec_cbc_t encdecfunc;
- struct page *in_page, *out_page;
- unsigned in_offs, out_offs;
-
- if (cmd == READ) {
- in_page = raw_page;
- in_offs = raw_off;
- out_page = loop_page;
- out_offs = loop_off;
- encdecfunc = tfm->crt_u.cipher.cit_decrypt_iv;
- } else {
- in_page = loop_page;
- in_offs = loop_off;
- out_page = raw_page;
- out_offs = raw_off;
- encdecfunc = tfm->crt_u.cipher.cit_encrypt_iv;
- }
-
- while (size > 0) {
- const int sz = min(size, LOOP_IV_SECTOR_SIZE);
- u32 iv[4] = { 0, };
- iv[0] = cpu_to_le32(IV & 0xffffffff);
-
- sg_in.page = in_page;
- sg_in.offset = in_offs;
- sg_in.length = sz;
-
- sg_out.page = out_page;
- sg_out.offset = out_offs;
- sg_out.length = sz;
-
- encdecfunc(tfm, &sg_out, &sg_in, sz, (u8 *)iv);
-
- IV++;
- size -= sz;
- in_offs += sz;
- out_offs += sz;
- }
-
- return 0;
-}
-
-static int
-cryptoloop_transfer(struct loop_device *lo, int cmd,
- struct page *raw_page, unsigned raw_off,
- struct page *loop_page, unsigned loop_off,
- int size, sector_t IV)
-{
- struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data;
- if(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB)
- {
- lo->transfer = cryptoloop_transfer_ecb;
- return cryptoloop_transfer_ecb(lo, cmd, raw_page, raw_off,
- loop_page, loop_off, size, IV);
- }
- if(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_CBC)
- {
- lo->transfer = cryptoloop_transfer_cbc;
- return cryptoloop_transfer_cbc(lo, cmd, raw_page, raw_off,
- loop_page, loop_off, size, IV);
- }
-
- /* This is not supposed to happen */
-
- printk( KERN_ERR "cryptoloop: unsupported cipher mode in cryptoloop_transfer!\n");
- return -EINVAL;
-}
-
-static int
-cryptoloop_ioctl(struct loop_device *lo, int cmd, unsigned long arg)
-{
- return -EINVAL;
-}
-
-static int
-cryptoloop_release(struct loop_device *lo)
-{
- struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data;
- if (tfm != NULL) {
- crypto_free_tfm(tfm);
- lo->key_data = NULL;
- return 0;
- }
- printk(KERN_ERR "cryptoloop_release(): tfm == NULL?\n");
- return -EINVAL;
-}
-
-static struct loop_func_table cryptoloop_funcs = {
- .number = LO_CRYPT_CRYPTOAPI,
- .init = cryptoloop_init,
- .ioctl = cryptoloop_ioctl,
- .transfer = cryptoloop_transfer,
- .release = cryptoloop_release,
- .owner = THIS_MODULE
-};
-
-static int __init
-init_cryptoloop(void)
-{
- int rc = loop_register_transfer(&cryptoloop_funcs);
-
- if (rc)
- printk(KERN_ERR "cryptoloop: loop_register_transfer failed\n");
- return rc;
-}
-
-static void __exit
-cleanup_cryptoloop(void)
-{
- if (loop_unregister_transfer(LO_CRYPT_CRYPTOAPI))
- printk(KERN_ERR
- "cryptoloop: loop_unregister_transfer failed\n");
-}
-
-module_init(init_cryptoloop);
-module_exit(cleanup_cryptoloop);
diff -urN a/drivers/block/Kconfig b/drivers/block/Kconfig
--- a/drivers/block/Kconfig 2004-07-21 15:40:46.000000000 -0400
+++ b/drivers/block/Kconfig 2004-07-21 15:53:02.000000000 -0400
@@ -229,12 +229,8 @@
on a remote file server.

There are several ways of encrypting disks. Some of these require
- kernel patches. The vanilla kernel offers the cryptoloop option
- and a Device Mapper target (which is superior, as it supports all
- file systems). If you want to use the cryptoloop, say Y to both
- LOOP and CRYPTOLOOP, and make sure you have a recent (version 2.12
- or later) version of util-linux. Additionally, be aware that
- the cryptoloop is not safe for storing journaled filesystems.
+ kernel patches. The vanilla kernel offers a Device Mapper target
+ which supports all file systems.

Note that this loop device has nothing to do with the loopback
device used for network connections from the machine to itself.
@@ -244,20 +240,6 @@

Most users will answer N here.

-config BLK_DEV_CRYPTOLOOP
- tristate "Cryptoloop Support"
- select CRYPTO
- depends on BLK_DEV_LOOP
- ---help---
- Say Y here if you want to be able to use the ciphers that are
- provided by the CryptoAPI as loop transformation. This might be
- used as hard disk encryption.
-
- WARNING: This device is not safe for journaled file systems like
- ext3 or Reiserfs. Please use the Device Mapper crypto module
- instead, which can be configured to be on-disk compatible with the
- cryptoloop device.
-
config BLK_DEV_NBD
tristate "Network block device support"
depends on NET
diff -urN a/drivers/block/Makefile b/drivers/block/Makefile
--- a/drivers/block/Makefile 2004-07-21 15:40:46.000000000 -0400
+++ b/drivers/block/Makefile 2004-07-21 15:53:41.000000000 -0400
@@ -38,7 +38,6 @@

obj-$(CONFIG_BLK_DEV_UMEM) += umem.o
obj-$(CONFIG_BLK_DEV_NBD) += nbd.o
-obj-$(CONFIG_BLK_DEV_CRYPTOLOOP) += cryptoloop.o

obj-$(CONFIG_VIODASD) += viodasd.o
obj-$(CONFIG_BLK_DEV_SX8) += sx8.o