[PATCH resend 10/18] crypto: arm64/aes-ce-ccm: add non-SIMD generic fallback
Ard Biesheuvel
ard.biesheuvel at linaro.org
Mon Jul 24 03:28:12 PDT 2017
The arm64 kernel will shortly disallow nested kernel mode NEON.
So honour this in the ARMv8 Crypto Extensions implementation of
CCM-AES, and fall back to a scalar implementation using the generic
crypto helpers for AES, XOR and incrementing the CTR counter.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
---
arch/arm64/crypto/Kconfig | 1 +
arch/arm64/crypto/aes-ce-ccm-glue.c | 174 ++++++++++++++++----
2 files changed, 140 insertions(+), 35 deletions(-)
diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig
index 2fd4bb6d0b5a..ba637765c19a 100644
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -59,6 +59,7 @@ config CRYPTO_AES_ARM64_CE_CCM
depends on ARM64 && KERNEL_MODE_NEON
select CRYPTO_ALGAPI
select CRYPTO_AES_ARM64_CE
+ select CRYPTO_AES_ARM64
select CRYPTO_AEAD
config CRYPTO_AES_ARM64_CE_BLK
diff --git a/arch/arm64/crypto/aes-ce-ccm-glue.c b/arch/arm64/crypto/aes-ce-ccm-glue.c
index 6a7dbc7c83a6..a1254036f2b1 100644
--- a/arch/arm64/crypto/aes-ce-ccm-glue.c
+++ b/arch/arm64/crypto/aes-ce-ccm-glue.c
@@ -1,7 +1,7 @@
/*
* aes-ccm-glue.c - AES-CCM transform for ARMv8 with Crypto Extensions
*
- * Copyright (C) 2013 - 2014 Linaro Ltd <ard.biesheuvel at linaro.org>
+ * Copyright (C) 2013 - 2017 Linaro Ltd <ard.biesheuvel at linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -9,6 +9,7 @@
*/
#include <asm/neon.h>
+#include <asm/simd.h>
#include <asm/unaligned.h>
#include <crypto/aes.h>
#include <crypto/scatterwalk.h>
@@ -44,6 +45,8 @@ asmlinkage void ce_aes_ccm_decrypt(u8 out[], u8 const in[], u32 cbytes,
asmlinkage void ce_aes_ccm_final(u8 mac[], u8 const ctr[], u32 const rk[],
u32 rounds);
+asmlinkage void __aes_arm64_encrypt(u32 *rk, u8 *out, const u8 *in, int rounds);
+
static int ccm_setkey(struct crypto_aead *tfm, const u8 *in_key,
unsigned int key_len)
{
@@ -103,7 +106,45 @@ static int ccm_init_mac(struct aead_request *req, u8 maciv[], u32 msglen)
return 0;
}
-static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[])
+static void ccm_update_mac(struct crypto_aes_ctx *key, u8 mac[], u8 const in[],
+ u32 abytes, u32 *macp, bool use_neon)
+{
+ if (likely(use_neon)) {
+ ce_aes_ccm_auth_data(mac, in, abytes, macp, key->key_enc,
+ num_rounds(key));
+ } else {
+ if (*macp > 0 && *macp < AES_BLOCK_SIZE) {
+ int added = min(abytes, AES_BLOCK_SIZE - *macp);
+
+ crypto_xor(&mac[*macp], in, added);
+
+ *macp += added;
+ in += added;
+ abytes -= added;
+ }
+
+ while (abytes > AES_BLOCK_SIZE) {
+ __aes_arm64_encrypt(key->key_enc, mac, mac,
+ num_rounds(key));
+ crypto_xor(mac, in, AES_BLOCK_SIZE);
+
+ in += AES_BLOCK_SIZE;
+ abytes -= AES_BLOCK_SIZE;
+ }
+
+ if (abytes > 0) {
+ __aes_arm64_encrypt(key->key_enc, mac, mac,
+ num_rounds(key));
+ crypto_xor(mac, in, abytes);
+ *macp = abytes;
+ } else {
+ *macp = 0;
+ }
+ }
+}
+
+static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[],
+ bool use_neon)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_aead_ctx(aead);
@@ -122,8 +163,7 @@ static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[])
ltag.len = 6;
}
- ce_aes_ccm_auth_data(mac, (u8 *)<ag, ltag.len, &macp, ctx->key_enc,
- num_rounds(ctx));
+ ccm_update_mac(ctx, mac, (u8 *)<ag, ltag.len, &macp, use_neon);
scatterwalk_start(&walk, req->src);
do {
@@ -135,8 +175,7 @@ static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[])
n = scatterwalk_clamp(&walk, len);
}
p = scatterwalk_map(&walk);
- ce_aes_ccm_auth_data(mac, p, n, &macp, ctx->key_enc,
- num_rounds(ctx));
+ ccm_update_mac(ctx, mac, p, n, &macp, use_neon);
len -= n;
scatterwalk_unmap(p);
@@ -145,6 +184,56 @@ static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[])
} while (len);
}
+static int ccm_crypt_fallback(struct skcipher_walk *walk, u8 mac[], u8 iv0[],
+ struct crypto_aes_ctx *ctx, bool enc)
+{
+ u8 buf[AES_BLOCK_SIZE];
+ int err = 0;
+
+ while (walk->nbytes) {
+ int blocks = walk->nbytes / AES_BLOCK_SIZE;
+ u32 tail = walk->nbytes % AES_BLOCK_SIZE;
+ u8 *dst = walk->dst.virt.addr;
+ u8 *src = walk->src.virt.addr;
+ u32 nbytes = walk->nbytes;
+
+ if (nbytes == walk->total && tail > 0) {
+ blocks++;
+ tail = 0;
+ }
+
+ do {
+ u32 bsize = AES_BLOCK_SIZE;
+
+ if (nbytes < AES_BLOCK_SIZE)
+ bsize = nbytes;
+
+ crypto_inc(walk->iv, AES_BLOCK_SIZE);
+ __aes_arm64_encrypt(ctx->key_enc, buf, walk->iv,
+ num_rounds(ctx));
+ __aes_arm64_encrypt(ctx->key_enc, mac, mac,
+ num_rounds(ctx));
+ if (enc)
+ crypto_xor(mac, src, bsize);
+ crypto_xor_cpy(dst, src, buf, bsize);
+ if (!enc)
+ crypto_xor(mac, dst, bsize);
+ dst += bsize;
+ src += bsize;
+ nbytes -= bsize;
+ } while (--blocks);
+
+ err = skcipher_walk_done(walk, tail);
+ }
+
+ if (!err) {
+ __aes_arm64_encrypt(ctx->key_enc, buf, iv0, num_rounds(ctx));
+ __aes_arm64_encrypt(ctx->key_enc, mac, mac, num_rounds(ctx));
+ crypto_xor(mac, buf, AES_BLOCK_SIZE);
+ }
+ return err;
+}
+
static int ccm_encrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
@@ -153,39 +242,46 @@ static int ccm_encrypt(struct aead_request *req)
u8 __aligned(8) mac[AES_BLOCK_SIZE];
u8 buf[AES_BLOCK_SIZE];
u32 len = req->cryptlen;
+ bool use_neon = may_use_simd();
int err;
err = ccm_init_mac(req, mac, len);
if (err)
return err;
- kernel_neon_begin_partial(6);
+ if (likely(use_neon))
+ kernel_neon_begin();
if (req->assoclen)
- ccm_calculate_auth_mac(req, mac);
+ ccm_calculate_auth_mac(req, mac, use_neon);
/* preserve the original iv for the final round */
memcpy(buf, req->iv, AES_BLOCK_SIZE);
err = skcipher_walk_aead_encrypt(&walk, req, true);
- while (walk.nbytes) {
- u32 tail = walk.nbytes % AES_BLOCK_SIZE;
-
- if (walk.nbytes == walk.total)
- tail = 0;
+ if (likely(use_neon)) {
+ while (walk.nbytes) {
+ u32 tail = walk.nbytes % AES_BLOCK_SIZE;
- ce_aes_ccm_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
- walk.nbytes - tail, ctx->key_enc,
- num_rounds(ctx), mac, walk.iv);
+ if (walk.nbytes == walk.total)
+ tail = 0;
- err = skcipher_walk_done(&walk, tail);
- }
- if (!err)
- ce_aes_ccm_final(mac, buf, ctx->key_enc, num_rounds(ctx));
+ ce_aes_ccm_encrypt(walk.dst.virt.addr,
+ walk.src.virt.addr,
+ walk.nbytes - tail, ctx->key_enc,
+ num_rounds(ctx), mac, walk.iv);
- kernel_neon_end();
+ err = skcipher_walk_done(&walk, tail);
+ }
+ if (!err)
+ ce_aes_ccm_final(mac, buf, ctx->key_enc,
+ num_rounds(ctx));
+ kernel_neon_end();
+ } else {
+ err = ccm_crypt_fallback(&walk, mac, buf, ctx, true);
+ }
if (err)
return err;
@@ -205,38 +301,46 @@ static int ccm_decrypt(struct aead_request *req)
u8 __aligned(8) mac[AES_BLOCK_SIZE];
u8 buf[AES_BLOCK_SIZE];
u32 len = req->cryptlen - authsize;
+ bool use_neon = may_use_simd();
int err;
err = ccm_init_mac(req, mac, len);
if (err)
return err;
- kernel_neon_begin_partial(6);
+ if (likely(use_neon))
+ kernel_neon_begin();
if (req->assoclen)
- ccm_calculate_auth_mac(req, mac);
+ ccm_calculate_auth_mac(req, mac, use_neon);
/* preserve the original iv for the final round */
memcpy(buf, req->iv, AES_BLOCK_SIZE);
err = skcipher_walk_aead_decrypt(&walk, req, true);
- while (walk.nbytes) {
- u32 tail = walk.nbytes % AES_BLOCK_SIZE;
+ if (likely(use_neon)) {
+ while (walk.nbytes) {
+ u32 tail = walk.nbytes % AES_BLOCK_SIZE;
- if (walk.nbytes == walk.total)
- tail = 0;
+ if (walk.nbytes == walk.total)
+ tail = 0;
- ce_aes_ccm_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
- walk.nbytes - tail, ctx->key_enc,
- num_rounds(ctx), mac, walk.iv);
+ ce_aes_ccm_decrypt(walk.dst.virt.addr,
+ walk.src.virt.addr,
+ walk.nbytes - tail, ctx->key_enc,
+ num_rounds(ctx), mac, walk.iv);
- err = skcipher_walk_done(&walk, tail);
- }
- if (!err)
- ce_aes_ccm_final(mac, buf, ctx->key_enc, num_rounds(ctx));
+ err = skcipher_walk_done(&walk, tail);
+ }
+ if (!err)
+ ce_aes_ccm_final(mac, buf, ctx->key_enc,
+ num_rounds(ctx));
- kernel_neon_end();
+ kernel_neon_end();
+ } else {
+ err = ccm_crypt_fallback(&walk, mac, buf, ctx, false);
+ }
if (err)
return err;
--
2.9.3
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