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);