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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/block/cryptoloop.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/block/cryptoloop.c')
-rw-r--r-- | drivers/block/cryptoloop.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/drivers/block/cryptoloop.c b/drivers/block/cryptoloop.c new file mode 100644 index 000000000000..5be6f998d8c5 --- /dev/null +++ b/drivers/block/cryptoloop.c @@ -0,0 +1,268 @@ +/* + 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); |