Initial import

1 files changed, 216 insertions, 0 deletions

diff --git a/drivers/block/cryptoloop.c b/drivers/block/cryptoloop.c
new file mode 100644
index 000000000..99e773cb7
--- /dev/null
+++ b/drivers/block/cryptoloop.c
@@ -0,0 +1,216 @@
+/*
+   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/scatterlist.h>
+#include <asm/uaccess.h>
+#include "loop.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;
+	int cipher_len;
+	int mode_len;
+	char cms[LO_NAME_SIZE];			/* cipher-mode string */
+	char *cipher;
+	char *mode;
+	char *cmsp = cms;			/* c-m string pointer */
+	struct crypto_blkcipher *tfm;
+
+	/* 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 = cmsp;
+	cipher_len = strcspn(cmsp, "-");
+
+	mode = cmsp + cipher_len;
+	mode_len = 0;
+	if (*mode) {
+		mode++;
+		mode_len = strcspn(mode, "-");
+	}
+
+	if (!mode_len) {
+		mode = "cbc";
+		mode_len = 3;
+	}
+
+	if (cipher_len + mode_len + 3 > LO_NAME_SIZE)
+		return -EINVAL;
+
+	memmove(cms, mode, mode_len);
+	cmsp = cms + mode_len;
+	*cmsp++ = '(';
+	memcpy(cmsp, info->lo_crypt_name, cipher_len);
+	cmsp += cipher_len;
+	*cmsp++ = ')';
+	*cmsp = 0;
+
+	tfm = crypto_alloc_blkcipher(cms, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(tfm))
+		return PTR_ERR(tfm);
+
+	err = crypto_blkcipher_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_blkcipher(tfm);
+
+ out:
+	return err;
+}
+
+
+typedef int (*encdec_cbc_t)(struct blkcipher_desc *desc,
+			struct scatterlist *sg_out,
+			struct scatterlist *sg_in,
+			unsigned int nsg);
+
+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_blkcipher *tfm = lo->key_data;
+	struct blkcipher_desc desc = {
+		.tfm = tfm,
+		.flags = CRYPTO_TFM_REQ_MAY_SLEEP,
+	};
+	struct scatterlist sg_out;
+	struct scatterlist sg_in;
+
+	encdec_cbc_t encdecfunc;
+	struct page *in_page, *out_page;
+	unsigned in_offs, out_offs;
+	int err;
+
+	sg_init_table(&sg_out, 1);
+	sg_init_table(&sg_in, 1);
+
+	if (cmd == READ) {
+		in_page = raw_page;
+		in_offs = raw_off;
+		out_page = loop_page;
+		out_offs = loop_off;
+		encdecfunc = crypto_blkcipher_crt(tfm)->decrypt;
+	} else {
+		in_page = loop_page;
+		in_offs = loop_off;
+		out_page = raw_page;
+		out_offs = raw_off;
+		encdecfunc = crypto_blkcipher_crt(tfm)->encrypt;
+	}
+
+	while (size > 0) {
+		const int sz = min(size, LOOP_IV_SECTOR_SIZE);
+		u32 iv[4] = { 0, };
+		iv[0] = cpu_to_le32(IV & 0xffffffff);
+
+		sg_set_page(&sg_in, in_page, sz, in_offs);
+		sg_set_page(&sg_out, out_page, sz, out_offs);
+
+		desc.info = iv;
+		err = encdecfunc(&desc, &sg_out, &sg_in, sz);
+		if (err)
+			return err;
+
+		IV++;
+		size -= sz;
+		in_offs += sz;
+		out_offs += sz;
+	}
+
+	return 0;
+}
+
+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_blkcipher *tfm = lo->key_data;
+	if (tfm != NULL) {
+		crypto_free_blkcipher(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);