cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

ghash.c (4588B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * GHASH routines supporting VMX instructions on the Power 8
      4 *
      5 * Copyright (C) 2015, 2019 International Business Machines Inc.
      6 *
      7 * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
      8 *
      9 * Extended by Daniel Axtens <dja@axtens.net> to replace the fallback
     10 * mechanism. The new approach is based on arm64 code, which is:
     11 *   Copyright (C) 2014 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org>
     12 */
     13
     14#include <linux/types.h>
     15#include <linux/err.h>
     16#include <linux/crypto.h>
     17#include <linux/delay.h>
     18#include <asm/simd.h>
     19#include <asm/switch_to.h>
     20#include <crypto/aes.h>
     21#include <crypto/ghash.h>
     22#include <crypto/scatterwalk.h>
     23#include <crypto/internal/hash.h>
     24#include <crypto/internal/simd.h>
     25#include <crypto/b128ops.h>
     26
     27void gcm_init_p8(u128 htable[16], const u64 Xi[2]);
     28void gcm_gmult_p8(u64 Xi[2], const u128 htable[16]);
     29void gcm_ghash_p8(u64 Xi[2], const u128 htable[16],
     30		  const u8 *in, size_t len);
     31
     32struct p8_ghash_ctx {
     33	/* key used by vector asm */
     34	u128 htable[16];
     35	/* key used by software fallback */
     36	be128 key;
     37};
     38
     39struct p8_ghash_desc_ctx {
     40	u64 shash[2];
     41	u8 buffer[GHASH_DIGEST_SIZE];
     42	int bytes;
     43};
     44
     45static int p8_ghash_init(struct shash_desc *desc)
     46{
     47	struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
     48
     49	dctx->bytes = 0;
     50	memset(dctx->shash, 0, GHASH_DIGEST_SIZE);
     51	return 0;
     52}
     53
     54static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
     55			   unsigned int keylen)
     56{
     57	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm));
     58
     59	if (keylen != GHASH_BLOCK_SIZE)
     60		return -EINVAL;
     61
     62	preempt_disable();
     63	pagefault_disable();
     64	enable_kernel_vsx();
     65	gcm_init_p8(ctx->htable, (const u64 *) key);
     66	disable_kernel_vsx();
     67	pagefault_enable();
     68	preempt_enable();
     69
     70	memcpy(&ctx->key, key, GHASH_BLOCK_SIZE);
     71
     72	return 0;
     73}
     74
     75static inline void __ghash_block(struct p8_ghash_ctx *ctx,
     76				 struct p8_ghash_desc_ctx *dctx)
     77{
     78	if (crypto_simd_usable()) {
     79		preempt_disable();
     80		pagefault_disable();
     81		enable_kernel_vsx();
     82		gcm_ghash_p8(dctx->shash, ctx->htable,
     83				dctx->buffer, GHASH_DIGEST_SIZE);
     84		disable_kernel_vsx();
     85		pagefault_enable();
     86		preempt_enable();
     87	} else {
     88		crypto_xor((u8 *)dctx->shash, dctx->buffer, GHASH_BLOCK_SIZE);
     89		gf128mul_lle((be128 *)dctx->shash, &ctx->key);
     90	}
     91}
     92
     93static inline void __ghash_blocks(struct p8_ghash_ctx *ctx,
     94				  struct p8_ghash_desc_ctx *dctx,
     95				  const u8 *src, unsigned int srclen)
     96{
     97	if (crypto_simd_usable()) {
     98		preempt_disable();
     99		pagefault_disable();
    100		enable_kernel_vsx();
    101		gcm_ghash_p8(dctx->shash, ctx->htable,
    102				src, srclen);
    103		disable_kernel_vsx();
    104		pagefault_enable();
    105		preempt_enable();
    106	} else {
    107		while (srclen >= GHASH_BLOCK_SIZE) {
    108			crypto_xor((u8 *)dctx->shash, src, GHASH_BLOCK_SIZE);
    109			gf128mul_lle((be128 *)dctx->shash, &ctx->key);
    110			srclen -= GHASH_BLOCK_SIZE;
    111			src += GHASH_BLOCK_SIZE;
    112		}
    113	}
    114}
    115
    116static int p8_ghash_update(struct shash_desc *desc,
    117			   const u8 *src, unsigned int srclen)
    118{
    119	unsigned int len;
    120	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
    121	struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
    122
    123	if (dctx->bytes) {
    124		if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
    125			memcpy(dctx->buffer + dctx->bytes, src,
    126				srclen);
    127			dctx->bytes += srclen;
    128			return 0;
    129		}
    130		memcpy(dctx->buffer + dctx->bytes, src,
    131			GHASH_DIGEST_SIZE - dctx->bytes);
    132
    133		__ghash_block(ctx, dctx);
    134
    135		src += GHASH_DIGEST_SIZE - dctx->bytes;
    136		srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
    137		dctx->bytes = 0;
    138	}
    139	len = srclen & ~(GHASH_DIGEST_SIZE - 1);
    140	if (len) {
    141		__ghash_blocks(ctx, dctx, src, len);
    142		src += len;
    143		srclen -= len;
    144	}
    145	if (srclen) {
    146		memcpy(dctx->buffer, src, srclen);
    147		dctx->bytes = srclen;
    148	}
    149	return 0;
    150}
    151
    152static int p8_ghash_final(struct shash_desc *desc, u8 *out)
    153{
    154	int i;
    155	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
    156	struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
    157
    158	if (dctx->bytes) {
    159		for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
    160			dctx->buffer[i] = 0;
    161		__ghash_block(ctx, dctx);
    162		dctx->bytes = 0;
    163	}
    164	memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
    165	return 0;
    166}
    167
    168struct shash_alg p8_ghash_alg = {
    169	.digestsize = GHASH_DIGEST_SIZE,
    170	.init = p8_ghash_init,
    171	.update = p8_ghash_update,
    172	.final = p8_ghash_final,
    173	.setkey = p8_ghash_setkey,
    174	.descsize = sizeof(struct p8_ghash_desc_ctx)
    175		+ sizeof(struct ghash_desc_ctx),
    176	.base = {
    177		 .cra_name = "ghash",
    178		 .cra_driver_name = "p8_ghash",
    179		 .cra_priority = 1000,
    180		 .cra_blocksize = GHASH_BLOCK_SIZE,
    181		 .cra_ctxsize = sizeof(struct p8_ghash_ctx),
    182		 .cra_module = THIS_MODULE,
    183	},
    184};