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+/* 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, Christoph Müllner <christoph.muellner@vrull.eu>
+// Copyright (c) 2023, Phoebe Chen <phoebe.chen@sifive.com>
+// Copyright (c) 2023, Jerry Shih <jerry.shih@sifive.com>
+// 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')
+
+#include <linux/linkage.h>
+
+.text
+.option arch, +zvkned
+
+#include "aes-macros.S"
+
+#define KEYP a0
+#define INP a1
+#define OUTP a2
+#define LEN a3
+#define IVP a4
+
+.macro __aes_crypt_zvkned enc, keylen
+ vle32.v v16, (INP)
+ aes_crypt v16, \enc, \keylen
+ vse32.v v16, (OUTP)
+ ret
+.endm
+
+.macro aes_crypt_zvkned enc
+ aes_begin KEYP, 128f, 192f
+ __aes_crypt_zvkned \enc, 256
+128:
+ __aes_crypt_zvkned \enc, 128
+192:
+ __aes_crypt_zvkned \enc, 192
+.endm
+
+// void aes_encrypt_zvkned(const struct crypto_aes_ctx *key,
+// const u8 in[16], u8 out[16]);
+SYM_FUNC_START(aes_encrypt_zvkned)
+ aes_crypt_zvkned 1
+SYM_FUNC_END(aes_encrypt_zvkned)
+
+// Same prototype and calling convention as the encryption function
+SYM_FUNC_START(aes_decrypt_zvkned)
+ aes_crypt_zvkned 0
+SYM_FUNC_END(aes_decrypt_zvkned)
+
+.macro __aes_ecb_crypt enc, keylen
+ srli t0, LEN, 2
+ // t0 is the remaining length in 32-bit words. It's a multiple of 4.
+1:
+ vsetvli t1, t0, e32, m8, ta, ma
+ sub t0, t0, t1 // Subtract number of words processed
+ slli t1, t1, 2 // Words to bytes
+ vle32.v v16, (INP)
+ aes_crypt v16, \enc, \keylen
+ vse32.v v16, (OUTP)
+ add INP, INP, t1
+ add OUTP, OUTP, t1
+ bnez t0, 1b
+
+ ret
+.endm
+
+.macro aes_ecb_crypt enc
+ aes_begin KEYP, 128f, 192f
+ __aes_ecb_crypt \enc, 256
+128:
+ __aes_ecb_crypt \enc, 128
+192:
+ __aes_ecb_crypt \enc, 192
+.endm
+
+// void aes_ecb_encrypt_zvkned(const struct crypto_aes_ctx *key,
+// const u8 *in, u8 *out, size_t len);
+//
+// |len| must be nonzero and a multiple of 16 (AES_BLOCK_SIZE).
+SYM_FUNC_START(aes_ecb_encrypt_zvkned)
+ aes_ecb_crypt 1
+SYM_FUNC_END(aes_ecb_encrypt_zvkned)
+
+// Same prototype and calling convention as the encryption function
+SYM_FUNC_START(aes_ecb_decrypt_zvkned)
+ aes_ecb_crypt 0
+SYM_FUNC_END(aes_ecb_decrypt_zvkned)
+
+.macro aes_cbc_encrypt keylen
+ vle32.v v16, (IVP) // Load IV
+1:
+ vle32.v v17, (INP) // Load plaintext block
+ vxor.vv v16, v16, v17 // XOR with IV or prev ciphertext block
+ aes_encrypt v16, \keylen // Encrypt
+ vse32.v v16, (OUTP) // Store ciphertext block
+ addi INP, INP, 16
+ addi OUTP, OUTP, 16
+ addi LEN, LEN, -16
+ bnez LEN, 1b
+
+ vse32.v v16, (IVP) // Store next IV
+ ret
+.endm
+
+.macro aes_cbc_decrypt keylen
+ srli LEN, LEN, 2 // Convert LEN from bytes to words
+ vle32.v v16, (IVP) // Load IV
+1:
+ vsetvli t0, LEN, e32, m4, ta, ma
+ vle32.v v20, (INP) // Load ciphertext blocks
+ vslideup.vi v16, v20, 4 // Setup prev ciphertext blocks
+ addi t1, t0, -4
+ vslidedown.vx v24, v20, t1 // Save last ciphertext block
+ aes_decrypt v20, \keylen // Decrypt the blocks
+ vxor.vv v20, v20, v16 // XOR with prev ciphertext blocks
+ vse32.v v20, (OUTP) // Store plaintext blocks
+ vmv.v.v v16, v24 // Next "IV" is last ciphertext block
+ slli t1, t0, 2 // Words to bytes
+ add INP, INP, t1
+ add OUTP, OUTP, t1
+ sub LEN, LEN, t0
+ bnez LEN, 1b
+
+ vsetivli zero, 4, e32, m1, ta, ma
+ vse32.v v16, (IVP) // Store next IV
+ ret
+.endm
+
+// void aes_cbc_encrypt_zvkned(const struct crypto_aes_ctx *key,
+// const u8 *in, u8 *out, size_t len, u8 iv[16]);
+//
+// |len| must be nonzero and a multiple of 16 (AES_BLOCK_SIZE).
+SYM_FUNC_START(aes_cbc_encrypt_zvkned)
+ aes_begin KEYP, 128f, 192f
+ aes_cbc_encrypt 256
+128:
+ aes_cbc_encrypt 128
+192:
+ aes_cbc_encrypt 192
+SYM_FUNC_END(aes_cbc_encrypt_zvkned)
+
+// Same prototype and calling convention as the encryption function
+SYM_FUNC_START(aes_cbc_decrypt_zvkned)
+ aes_begin KEYP, 128f, 192f
+ aes_cbc_decrypt 256
+128:
+ aes_cbc_decrypt 128
+192:
+ aes_cbc_decrypt 192
+SYM_FUNC_END(aes_cbc_decrypt_zvkned)
+
+.macro aes_cbc_cts_encrypt keylen
+
+ // CBC-encrypt all blocks except the last. But don't store the
+ // second-to-last block to the output buffer yet, since it will be
+ // handled specially in the ciphertext stealing step. Exception: if the
+ // message is single-block, still encrypt the last (and only) block.
+ li t0, 16
+ j 2f
+1:
+ vse32.v v16, (OUTP) // Store ciphertext block
+ addi OUTP, OUTP, 16
+2:
+ vle32.v v17, (INP) // Load plaintext block
+ vxor.vv v16, v16, v17 // XOR with IV or prev ciphertext block
+ aes_encrypt v16, \keylen // Encrypt
+ addi INP, INP, 16
+ addi LEN, LEN, -16
+ bgt LEN, t0, 1b // Repeat if more than one block remains
+
+ // Special case: if the message is a single block, just do CBC.
+ beqz LEN, .Lcts_encrypt_done\@
+
+ // Encrypt the last two blocks using ciphertext stealing as follows:
+ // C[n-1] = Encrypt(Encrypt(P[n-1] ^ C[n-2]) ^ P[n])
+ // C[n] = Encrypt(P[n-1] ^ C[n-2])[0..LEN]
+ //
+ // C[i] denotes the i'th ciphertext block, and likewise P[i] the i'th
+ // plaintext block. Block n, the last block, may be partial; its length
+ // is 1 <= LEN <= 16. If there are only 2 blocks, C[n-2] means the IV.
+ //
+ // v16 already contains Encrypt(P[n-1] ^ C[n-2]).
+ // INP points to P[n]. OUTP points to where C[n-1] should go.
+ // To support in-place encryption, load P[n] before storing C[n].
+ addi t0, OUTP, 16 // Get pointer to where C[n] should go
+ vsetvli zero, LEN, e8, m1, tu, ma
+ vle8.v v17, (INP) // Load P[n]
+ vse8.v v16, (t0) // Store C[n]
+ vxor.vv v16, v16, v17 // v16 = Encrypt(P[n-1] ^ C[n-2]) ^ P[n]
+ vsetivli zero, 4, e32, m1, ta, ma
+ aes_encrypt v16, \keylen
+.Lcts_encrypt_done\@:
+ vse32.v v16, (OUTP) // Store C[n-1] (or C[n] in single-block case)
+ ret
+.endm
+
+#define LEN32 t4 // Length of remaining full blocks in 32-bit words
+#define LEN_MOD16 t5 // Length of message in bytes mod 16
+
+.macro aes_cbc_cts_decrypt keylen
+ andi LEN32, LEN, ~15
+ srli LEN32, LEN32, 2
+ andi LEN_MOD16, LEN, 15
+
+ // Save C[n-2] in v28 so that it's available later during the ciphertext
+ // stealing step. If there are fewer than three blocks, C[n-2] means
+ // the IV, otherwise it means the third-to-last ciphertext block.
+ vmv.v.v v28, v16 // IV
+ add t0, LEN, -33
+ bltz t0, .Lcts_decrypt_loop\@
+ andi t0, t0, ~15
+ add t0, t0, INP
+ vle32.v v28, (t0)
+
+ // CBC-decrypt all full blocks. For the last full block, or the last 2
+ // full blocks if the message is block-aligned, this doesn't write the
+ // correct output blocks (unless the message is only a single block),
+ // because it XORs the wrong values with the raw AES plaintexts. But we
+ // fix this after this loop without redoing the AES decryptions. This
+ // approach allows more of the AES decryptions to be parallelized.
+.Lcts_decrypt_loop\@:
+ vsetvli t0, LEN32, e32, m4, ta, ma
+ addi t1, t0, -4
+ vle32.v v20, (INP) // Load next set of ciphertext blocks
+ vmv.v.v v24, v16 // Get IV or last ciphertext block of prev set
+ vslideup.vi v24, v20, 4 // Setup prev ciphertext blocks
+ vslidedown.vx v16, v20, t1 // Save last ciphertext block of this set
+ aes_decrypt v20, \keylen // Decrypt this set of blocks
+ vxor.vv v24, v24, v20 // XOR prev ciphertext blocks with decrypted blocks
+ vse32.v v24, (OUTP) // Store this set of plaintext blocks
+ sub LEN32, LEN32, t0
+ slli t0, t0, 2 // Words to bytes
+ add INP, INP, t0
+ add OUTP, OUTP, t0
+ bnez LEN32, .Lcts_decrypt_loop\@
+
+ vsetivli zero, 4, e32, m4, ta, ma
+ vslidedown.vx v20, v20, t1 // Extract raw plaintext of last full block
+ addi t0, OUTP, -16 // Get pointer to last full plaintext block
+ bnez LEN_MOD16, .Lcts_decrypt_non_block_aligned\@
+
+ // Special case: if the message is a single block, just do CBC.
+ li t1, 16
+ beq LEN, t1, .Lcts_decrypt_done\@
+
+ // Block-aligned message. Just fix up the last 2 blocks. We need:
+ //
+ // P[n-1] = Decrypt(C[n]) ^ C[n-2]
+ // P[n] = Decrypt(C[n-1]) ^ C[n]
+ //
+ // We have C[n] in v16, Decrypt(C[n]) in v20, and C[n-2] in v28.
+ // Together with Decrypt(C[n-1]) ^ C[n-2] from the output buffer, this
+ // is everything needed to fix the output without re-decrypting blocks.
+ addi t1, OUTP, -32 // Get pointer to where P[n-1] should go
+ vxor.vv v20, v20, v28 // Decrypt(C[n]) ^ C[n-2] == P[n-1]
+ vle32.v v24, (t1) // Decrypt(C[n-1]) ^ C[n-2]
+ vse32.v v20, (t1) // Store P[n-1]
+ vxor.vv v20, v24, v16 // Decrypt(C[n-1]) ^ C[n-2] ^ C[n] == P[n] ^ C[n-2]
+ j .Lcts_decrypt_finish\@
+
+.Lcts_decrypt_non_block_aligned\@:
+ // Decrypt the last two blocks using ciphertext stealing as follows:
+ //
+ // P[n-1] = Decrypt(C[n] || Decrypt(C[n-1])[LEN_MOD16..16]) ^ C[n-2]
+ // P[n] = (Decrypt(C[n-1]) ^ C[n])[0..LEN_MOD16]
+ //
+ // We already have Decrypt(C[n-1]) in v20 and C[n-2] in v28.
+ vmv.v.v v16, v20 // v16 = Decrypt(C[n-1])
+ vsetvli zero, LEN_MOD16, e8, m1, tu, ma
+ vle8.v v20, (INP) // v20 = C[n] || Decrypt(C[n-1])[LEN_MOD16..16]
+ vxor.vv v16, v16, v20 // v16 = Decrypt(C[n-1]) ^ C[n]
+ vse8.v v16, (OUTP) // Store P[n]
+ vsetivli zero, 4, e32, m1, ta, ma
+ aes_decrypt v20, \keylen // v20 = Decrypt(C[n] || Decrypt(C[n-1])[LEN_MOD16..16])
+.Lcts_decrypt_finish\@:
+ vxor.vv v20, v20, v28 // XOR with C[n-2]
+ vse32.v v20, (t0) // Store last full plaintext block
+.Lcts_decrypt_done\@:
+ ret
+.endm
+
+.macro aes_cbc_cts_crypt keylen
+ vle32.v v16, (IVP) // Load IV
+ beqz a5, .Lcts_decrypt\@
+ aes_cbc_cts_encrypt \keylen
+.Lcts_decrypt\@:
+ aes_cbc_cts_decrypt \keylen
+.endm
+
+// void aes_cbc_cts_crypt_zvkned(const struct crypto_aes_ctx *key,
+// const u8 *in, u8 *out, size_t len,
+// const u8 iv[16], bool enc);
+//
+// Encrypts or decrypts a message with the CS3 variant of AES-CBC-CTS.
+// This is the variant that unconditionally swaps the last two blocks.
+SYM_FUNC_START(aes_cbc_cts_crypt_zvkned)
+ aes_begin KEYP, 128f, 192f
+ aes_cbc_cts_crypt 256
+128:
+ aes_cbc_cts_crypt 128
+192:
+ aes_cbc_cts_crypt 192
+SYM_FUNC_END(aes_cbc_cts_crypt_zvkned)