163 lines
4.1 KiB
C
163 lines
4.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* AES XTS routines supporting VMX In-core instructions on Power 8
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*
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* Copyright (C) 2015 International Business Machines Inc.
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*
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* Author: Leonidas S. Barbosa <leosilva@linux.vnet.ibm.com>
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*/
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#include <asm/simd.h>
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#include <asm/switch_to.h>
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#include <crypto/aes.h>
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#include <crypto/internal/simd.h>
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#include <crypto/internal/skcipher.h>
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#include <crypto/xts.h>
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#include "aesp8-ppc.h"
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struct p8_aes_xts_ctx {
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struct crypto_skcipher *fallback;
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struct aes_key enc_key;
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struct aes_key dec_key;
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struct aes_key tweak_key;
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};
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static int p8_aes_xts_init(struct crypto_skcipher *tfm)
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{
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struct p8_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
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struct crypto_skcipher *fallback;
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fallback = crypto_alloc_skcipher("xts(aes)", 0,
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CRYPTO_ALG_NEED_FALLBACK |
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CRYPTO_ALG_ASYNC);
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if (IS_ERR(fallback)) {
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pr_err("Failed to allocate xts(aes) fallback: %ld\n",
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PTR_ERR(fallback));
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return PTR_ERR(fallback);
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}
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crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
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crypto_skcipher_reqsize(fallback));
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ctx->fallback = fallback;
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return 0;
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}
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static void p8_aes_xts_exit(struct crypto_skcipher *tfm)
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{
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struct p8_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
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crypto_free_skcipher(ctx->fallback);
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}
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static int p8_aes_xts_setkey(struct crypto_skcipher *tfm, const u8 *key,
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unsigned int keylen)
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{
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struct p8_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
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int ret;
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ret = xts_verify_key(tfm, key, keylen);
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if (ret)
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return ret;
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preempt_disable();
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pagefault_disable();
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enable_kernel_vsx();
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ret = aes_p8_set_encrypt_key(key + keylen/2, (keylen/2) * 8, &ctx->tweak_key);
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ret |= aes_p8_set_encrypt_key(key, (keylen/2) * 8, &ctx->enc_key);
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ret |= aes_p8_set_decrypt_key(key, (keylen/2) * 8, &ctx->dec_key);
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disable_kernel_vsx();
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pagefault_enable();
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preempt_enable();
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ret |= crypto_skcipher_setkey(ctx->fallback, key, keylen);
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return ret ? -EINVAL : 0;
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}
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static int p8_aes_xts_crypt(struct skcipher_request *req, int enc)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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const struct p8_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
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struct skcipher_walk walk;
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unsigned int nbytes;
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u8 tweak[AES_BLOCK_SIZE];
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int ret;
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if (req->cryptlen < AES_BLOCK_SIZE)
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return -EINVAL;
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if (!crypto_simd_usable() || (req->cryptlen % XTS_BLOCK_SIZE) != 0) {
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struct skcipher_request *subreq = skcipher_request_ctx(req);
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*subreq = *req;
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skcipher_request_set_tfm(subreq, ctx->fallback);
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return enc ? crypto_skcipher_encrypt(subreq) :
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crypto_skcipher_decrypt(subreq);
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}
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ret = skcipher_walk_virt(&walk, req, false);
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if (ret)
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return ret;
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preempt_disable();
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pagefault_disable();
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enable_kernel_vsx();
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aes_p8_encrypt(walk.iv, tweak, &ctx->tweak_key);
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disable_kernel_vsx();
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pagefault_enable();
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preempt_enable();
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while ((nbytes = walk.nbytes) != 0) {
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preempt_disable();
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pagefault_disable();
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enable_kernel_vsx();
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if (enc)
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aes_p8_xts_encrypt(walk.src.virt.addr,
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walk.dst.virt.addr,
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round_down(nbytes, AES_BLOCK_SIZE),
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&ctx->enc_key, NULL, tweak);
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else
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aes_p8_xts_decrypt(walk.src.virt.addr,
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walk.dst.virt.addr,
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round_down(nbytes, AES_BLOCK_SIZE),
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&ctx->dec_key, NULL, tweak);
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disable_kernel_vsx();
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pagefault_enable();
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preempt_enable();
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ret = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
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}
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return ret;
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}
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static int p8_aes_xts_encrypt(struct skcipher_request *req)
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{
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return p8_aes_xts_crypt(req, 1);
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}
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static int p8_aes_xts_decrypt(struct skcipher_request *req)
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{
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return p8_aes_xts_crypt(req, 0);
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}
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struct skcipher_alg p8_aes_xts_alg = {
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.base.cra_name = "xts(aes)",
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.base.cra_driver_name = "p8_aes_xts",
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.base.cra_module = THIS_MODULE,
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.base.cra_priority = 2000,
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.base.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
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.base.cra_blocksize = AES_BLOCK_SIZE,
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.base.cra_ctxsize = sizeof(struct p8_aes_xts_ctx),
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.setkey = p8_aes_xts_setkey,
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.encrypt = p8_aes_xts_encrypt,
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.decrypt = p8_aes_xts_decrypt,
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.init = p8_aes_xts_init,
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.exit = p8_aes_xts_exit,
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.min_keysize = 2 * AES_MIN_KEY_SIZE,
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.max_keysize = 2 * AES_MAX_KEY_SIZE,
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.ivsize = AES_BLOCK_SIZE,
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};
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