--- /dev/null
+/**
+ * AES XTS routines supporting VMX In-core instructions on Power 8
+ *
+ * Copyright (C) 2015 International Business Machines Inc.
+ *
+ * This program 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 Foundations; version 2 only.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY of FITNESS FOR A PARTICUPAR 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 program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Author: Leonidas S. Barbosa <leosilva@linux.vnet.ibm.com>
+ */
+
+#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/crypto.h>
+#include <linux/delay.h>
+#include <linux/hardirq.h>
+#include <asm/switch_to.h>
+#include <crypto/aes.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/xts.h>
+
+#include "aesp8-ppc.h"
+
+struct p8_aes_xts_ctx {
+ struct crypto_blkcipher *fallback;
+ struct aes_key enc_key;
+ struct aes_key dec_key;
+ struct aes_key tweak_key;
+};
+
+static int p8_aes_xts_init(struct crypto_tfm *tfm)
+{
+ const char *alg;
+ struct crypto_blkcipher *fallback;
+ struct p8_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ if (!(alg = crypto_tfm_alg_name(tfm))) {
+ printk(KERN_ERR "Failed to get algorithm name.\n");
+ return -ENOENT;
+ }
+
+ fallback =
+ crypto_alloc_blkcipher(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
+ if (IS_ERR(fallback)) {
+ printk(KERN_ERR
+ "Failed to allocate transformation for '%s': %ld\n",
+ alg, PTR_ERR(fallback));
+ return PTR_ERR(fallback);
+ }
+ printk(KERN_INFO "Using '%s' as fallback implementation.\n",
+ crypto_tfm_alg_driver_name((struct crypto_tfm *) fallback));
+
+ crypto_blkcipher_set_flags(
+ fallback,
+ crypto_blkcipher_get_flags((struct crypto_blkcipher *)tfm));
+ ctx->fallback = fallback;
+
+ return 0;
+}
+
+static void p8_aes_xts_exit(struct crypto_tfm *tfm)
+{
+ struct p8_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ if (ctx->fallback) {
+ crypto_free_blkcipher(ctx->fallback);
+ ctx->fallback = NULL;
+ }
+}
+
+static int p8_aes_xts_setkey(struct crypto_tfm *tfm, const u8 *key,
+ unsigned int keylen)
+{
+ int ret;
+ struct p8_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ ret = xts_check_key(tfm, key, keylen);
+ if (ret)
+ return ret;
+
+ preempt_disable();
+ pagefault_disable();
+ enable_kernel_vsx();
+ ret = aes_p8_set_encrypt_key(key + keylen/2, (keylen/2) * 8, &ctx->tweak_key);
+ ret += aes_p8_set_encrypt_key(key, (keylen/2) * 8, &ctx->enc_key);
+ ret += aes_p8_set_decrypt_key(key, (keylen/2) * 8, &ctx->dec_key);
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
+
+ ret += crypto_blkcipher_setkey(ctx->fallback, key, keylen);
+ return ret;
+}
+
+static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
+ struct scatterlist *dst,
+ struct scatterlist *src,
+ unsigned int nbytes, int enc)
+{
+ int ret;
+ u8 tweak[AES_BLOCK_SIZE];
+ u8 *iv;
+ struct blkcipher_walk walk;
+ struct p8_aes_xts_ctx *ctx =
+ crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
+ struct blkcipher_desc fallback_desc = {
+ .tfm = ctx->fallback,
+ .info = desc->info,
+ .flags = desc->flags
+ };
+
+ if (in_interrupt()) {
+ ret = enc ? crypto_blkcipher_encrypt(&fallback_desc, dst, src, nbytes) :
+ crypto_blkcipher_decrypt(&fallback_desc, dst, src, nbytes);
+ } else {
+ preempt_disable();
+ pagefault_disable();
+ enable_kernel_vsx();
+
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+
+ iv = (u8 *)walk.iv;
+ ret = blkcipher_walk_virt(desc, &walk);
+ memset(tweak, 0, AES_BLOCK_SIZE);
+ aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
+
+ while ((nbytes = walk.nbytes)) {
+ if (enc)
+ aes_p8_xts_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
+ nbytes & AES_BLOCK_MASK, &ctx->enc_key, NULL, tweak);
+ else
+ aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
+ nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
+
+ nbytes &= AES_BLOCK_SIZE - 1;
+ ret = blkcipher_walk_done(desc, &walk, nbytes);
+ }
+
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
+ }
+ return ret;
+}
+
+static int p8_aes_xts_encrypt(struct blkcipher_desc *desc,
+ struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ return p8_aes_xts_crypt(desc, dst, src, nbytes, 1);
+}
+
+static int p8_aes_xts_decrypt(struct blkcipher_desc *desc,
+ struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ return p8_aes_xts_crypt(desc, dst, src, nbytes, 0);
+}
+
+struct crypto_alg p8_aes_xts_alg = {
+ .cra_name = "xts(aes)",
+ .cra_driver_name = "p8_aes_xts",
+ .cra_module = THIS_MODULE,
+ .cra_priority = 2000,
+ .cra_type = &crypto_blkcipher_type,
+ .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK,
+ .cra_alignmask = 0,
+ .cra_blocksize = AES_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(struct p8_aes_xts_ctx),
+ .cra_init = p8_aes_xts_init,
+ .cra_exit = p8_aes_xts_exit,
+ .cra_blkcipher = {
+ .ivsize = AES_BLOCK_SIZE,
+ .min_keysize = 2 * AES_MIN_KEY_SIZE,
+ .max_keysize = 2 * AES_MAX_KEY_SIZE,
+ .setkey = p8_aes_xts_setkey,
+ .encrypt = p8_aes_xts_encrypt,
+ .decrypt = p8_aes_xts_decrypt,
+ }
+};
projects / cascardo / linux.git / commitdiff