| /** |
| * AES CTR routines supporting VMX instructions on the 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 Foundation; 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 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 program; if not, write to the Free Software |
| * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| * |
| * Author: Marcelo Henrique Cerri <mhcerri@br.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 "aesp8-ppc.h" |
| |
| struct p8_aes_ctr_ctx { |
| struct crypto_blkcipher *fallback; |
| struct aes_key enc_key; |
| }; |
| |
| static int p8_aes_ctr_init(struct crypto_tfm *tfm) |
| { |
| const char *alg; |
| struct crypto_blkcipher *fallback; |
| struct p8_aes_ctr_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_ctr_exit(struct crypto_tfm *tfm) |
| { |
| struct p8_aes_ctr_ctx *ctx = crypto_tfm_ctx(tfm); |
| |
| if (ctx->fallback) { |
| crypto_free_blkcipher(ctx->fallback); |
| ctx->fallback = NULL; |
| } |
| } |
| |
| static int p8_aes_ctr_setkey(struct crypto_tfm *tfm, const u8 *key, |
| unsigned int keylen) |
| { |
| int ret; |
| struct p8_aes_ctr_ctx *ctx = crypto_tfm_ctx(tfm); |
| |
| pagefault_disable(); |
| enable_kernel_altivec(); |
| enable_kernel_vsx(); |
| ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key); |
| pagefault_enable(); |
| |
| ret += crypto_blkcipher_setkey(ctx->fallback, key, keylen); |
| return ret; |
| } |
| |
| static void p8_aes_ctr_final(struct p8_aes_ctr_ctx *ctx, |
| struct blkcipher_walk *walk) |
| { |
| u8 *ctrblk = walk->iv; |
| u8 keystream[AES_BLOCK_SIZE]; |
| u8 *src = walk->src.virt.addr; |
| u8 *dst = walk->dst.virt.addr; |
| unsigned int nbytes = walk->nbytes; |
| |
| pagefault_disable(); |
| enable_kernel_altivec(); |
| enable_kernel_vsx(); |
| aes_p8_encrypt(ctrblk, keystream, &ctx->enc_key); |
| pagefault_enable(); |
| |
| crypto_xor(keystream, src, nbytes); |
| memcpy(dst, keystream, nbytes); |
| crypto_inc(ctrblk, AES_BLOCK_SIZE); |
| } |
| |
| static int p8_aes_ctr_crypt(struct blkcipher_desc *desc, |
| struct scatterlist *dst, |
| struct scatterlist *src, unsigned int nbytes) |
| { |
| int ret; |
| u64 inc; |
| struct blkcipher_walk walk; |
| struct p8_aes_ctr_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 = crypto_blkcipher_encrypt(&fallback_desc, dst, src, |
| nbytes); |
| } else { |
| blkcipher_walk_init(&walk, dst, src, nbytes); |
| ret = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE); |
| while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) { |
| pagefault_disable(); |
| enable_kernel_altivec(); |
| enable_kernel_vsx(); |
| aes_p8_ctr32_encrypt_blocks(walk.src.virt.addr, |
| walk.dst.virt.addr, |
| (nbytes & |
| AES_BLOCK_MASK) / |
| AES_BLOCK_SIZE, |
| &ctx->enc_key, |
| walk.iv); |
| pagefault_enable(); |
| |
| /* We need to update IV mostly for last bytes/round */ |
| inc = (nbytes & AES_BLOCK_MASK) / AES_BLOCK_SIZE; |
| if (inc > 0) |
| while (inc--) |
| crypto_inc(walk.iv, AES_BLOCK_SIZE); |
| |
| nbytes &= AES_BLOCK_SIZE - 1; |
| ret = blkcipher_walk_done(desc, &walk, nbytes); |
| } |
| if (walk.nbytes) { |
| p8_aes_ctr_final(ctx, &walk); |
| ret = blkcipher_walk_done(desc, &walk, 0); |
| } |
| } |
| |
| return ret; |
| } |
| |
| struct crypto_alg p8_aes_ctr_alg = { |
| .cra_name = "ctr(aes)", |
| .cra_driver_name = "p8_aes_ctr", |
| .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 = 1, |
| .cra_ctxsize = sizeof(struct p8_aes_ctr_ctx), |
| .cra_init = p8_aes_ctr_init, |
| .cra_exit = p8_aes_ctr_exit, |
| .cra_blkcipher = { |
| .ivsize = AES_BLOCK_SIZE, |
| .min_keysize = AES_MIN_KEY_SIZE, |
| .max_keysize = AES_MAX_KEY_SIZE, |
| .setkey = p8_aes_ctr_setkey, |
| .encrypt = p8_aes_ctr_crypt, |
| .decrypt = p8_aes_ctr_crypt, |
| }, |
| }; |