/* SPDX-License-Identifier: Apache-2.0 OR BSD-2-Clause */
//
// This file is dual-licensed, meaning that you can use it under your
// choice of either of the following two licenses:
//
// Copyright 2023 The OpenSSL Project Authors. All Rights Reserved.
//
// Licensed under the Apache License 2.0 (the "License"). You can obtain
// a copy in the file LICENSE in the source distribution or at
// https://www.openssl.org/source/license.html
//
// or
//
// Copyright (c) 2023, Jerry Shih <[email protected]>
// Copyright 2024 Google LLC
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// The generated code of this file depends on the following RISC-V extensions:
// - RV64I
// - RISC-V Vector ('V') with VLEN >= 128
// - RISC-V Vector AES block cipher extension ('Zvkned')
// - RISC-V Vector Cryptography Bit-manipulation extension ('Zvkb')
#include <linux/linkage.h>
.text
.option arch, +zvkned, +zvkb
#include "aes-macros.S"
#define KEYP a0
#define INP a1
#define OUTP a2
#define LEN a3
#define IVP a4
#define LEN32 a5
#define VL_E32 a6
#define VL_BLOCKS a7
.macro aes_ctr32_crypt keylen
// LEN32 = number of blocks, rounded up, in 32-bit words.
addi t0, LEN, 15
srli t0, t0, 4
slli LEN32, t0, 2
// Create a mask that selects the last 32-bit word of each 128-bit
// block. This is the word that contains the (big-endian) counter.
li t0, 0x88
vsetvli t1, zero, e8, m1, ta, ma
vmv.v.x v0, t0
// Load the IV into v31. The last 32-bit word contains the counter.
vsetivli zero, 4, e32, m1, ta, ma
vle32.v v31, (IVP)
// Convert the big-endian counter into little-endian.
vsetivli zero, 4, e32, m1, ta, mu
vrev8.v v31, v31, v0.t
// Splat the IV to v16 (with LMUL=4). The number of copies is the
// maximum number of blocks that will be processed per iteration.
vsetvli zero, LEN32, e32, m4, ta, ma
vmv.v.i v16, 0
vaesz.vs v16, v31
// v20 = [x, x, x, 0, x, x, x, 1, ...]
viota.m v20, v0, v0.t
// v16 = [IV0, IV1, IV2, counter+0, IV0, IV1, IV2, counter+1, ...]
vsetvli VL_E32, LEN32, e32, m4, ta, mu
vadd.vv v16, v16, v20, v0.t
j 2f
1:
// Set the number of blocks to process in this iteration. vl=VL_E32 is
// the length in 32-bit words, i.e. 4 times the number of blocks.
vsetvli VL_E32, LEN32, e32, m4, ta, mu
// Increment the counters by the number of blocks processed in the
// previous iteration.
vadd.vx v16, v16, VL_BLOCKS, v0.t
2:
// Prepare the AES inputs into v24.
vmv.v.v v24, v16
vrev8.v v24, v24, v0.t // Convert counters back to big-endian.
// Encrypt the AES inputs to create the next portion of the keystream.
aes_encrypt v24, \keylen
// XOR the data with the keystream.
vsetvli t0, LEN, e8, m4, ta, ma
vle8.v v20, (INP)
vxor.vv v20, v20, v24
vse8.v v20, (OUTP)
// Advance the pointers and update the remaining length.
add INP, INP, t0
add OUTP, OUTP, t0
sub LEN, LEN, t0
sub LEN32, LEN32, VL_E32
srli VL_BLOCKS, VL_E32, 2
// Repeat if more data remains.
bnez LEN, 1b
// Update *IVP to contain the next counter.
vsetivli zero, 4, e32, m1, ta, mu
vadd.vx v16, v16, VL_BLOCKS, v0.t
vrev8.v v16, v16, v0.t // Convert counters back to big-endian.
vse32.v v16, (IVP)
ret
.endm
// void aes_ctr32_crypt_zvkned_zvkb(const struct crypto_aes_ctx *key,
// const u8 *in, u8 *out, size_t len,
// u8 iv[16]);
SYM_FUNC_START(aes_ctr32_crypt_zvkned_zvkb)
aes_begin KEYP, 128f, 192f
aes_ctr32_crypt 256
128:
aes_ctr32_crypt 128
192:
aes_ctr32_crypt 192
SYM_FUNC_END(aes_ctr32_crypt_zvkned_zvkb)