root/arch/riscv/crypto/aes-macros.S
/* 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
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// 1. Redistributions of source code must retain the above copyright
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// This file contains macros that are shared by the other aes-*.S files.  The
// generated code of these macros depends on the following RISC-V extensions:
// - RV64I
// - RISC-V Vector ('V') with VLEN >= 128
// - RISC-V Vector AES block cipher extension ('Zvkned')

// Loads the AES round keys from \keyp into vector registers and jumps to code
// specific to the length of the key.  Specifically:
//   - If AES-128, loads round keys into v1-v11 and jumps to \label128.
//   - If AES-192, loads round keys into v1-v13 and jumps to \label192.
//   - If AES-256, loads round keys into v1-v15 and continues onwards.
//
// Also sets vl=4 and vtype=e32,m1,ta,ma.  Clobbers t0 and t1.
.macro  aes_begin       keyp, label128, label192, key_len
.ifb \key_len
        lwu             t0, 480(\keyp)  // t0 = key length in bytes
.endif
        li              t1, 24          // t1 = key length for AES-192
        vsetivli        zero, 4, e32, m1, ta, ma
        vle32.v         v1, (\keyp)
        addi            \keyp, \keyp, 16
        vle32.v         v2, (\keyp)
        addi            \keyp, \keyp, 16
        vle32.v         v3, (\keyp)
        addi            \keyp, \keyp, 16
        vle32.v         v4, (\keyp)
        addi            \keyp, \keyp, 16
        vle32.v         v5, (\keyp)
        addi            \keyp, \keyp, 16
        vle32.v         v6, (\keyp)
        addi            \keyp, \keyp, 16
        vle32.v         v7, (\keyp)
        addi            \keyp, \keyp, 16
        vle32.v         v8, (\keyp)
        addi            \keyp, \keyp, 16
        vle32.v         v9, (\keyp)
        addi            \keyp, \keyp, 16
        vle32.v         v10, (\keyp)
        addi            \keyp, \keyp, 16
        vle32.v         v11, (\keyp)
.ifb \key_len
        blt             t0, t1, \label128       // If AES-128, goto label128.
.else
        blt             \key_len, t1, \label128 // If AES-128, goto label128.
.endif
        addi            \keyp, \keyp, 16
        vle32.v         v12, (\keyp)
        addi            \keyp, \keyp, 16
        vle32.v         v13, (\keyp)
.ifb \key_len
        beq             t0, t1, \label192       // If AES-192, goto label192.
.else
        beq             \key_len, t1, \label192 // If AES-192, goto label192.
.endif
        // Else, it's AES-256.
        addi            \keyp, \keyp, 16
        vle32.v         v14, (\keyp)
        addi            \keyp, \keyp, 16
        vle32.v         v15, (\keyp)
.endm

// Encrypts \data using zvkned instructions, using the round keys loaded into
// v1-v11 (for AES-128), v1-v13 (for AES-192), or v1-v15 (for AES-256).  \keylen
// is the AES key length in bits.  vl and vtype must already be set
// appropriately.  Note that if vl > 4, multiple blocks are encrypted.
.macro  aes_encrypt     data, keylen
        vaesz.vs        \data, v1
        vaesem.vs       \data, v2
        vaesem.vs       \data, v3
        vaesem.vs       \data, v4
        vaesem.vs       \data, v5
        vaesem.vs       \data, v6
        vaesem.vs       \data, v7
        vaesem.vs       \data, v8
        vaesem.vs       \data, v9
        vaesem.vs       \data, v10
.if \keylen == 128
        vaesef.vs       \data, v11
.elseif \keylen == 192
        vaesem.vs       \data, v11
        vaesem.vs       \data, v12
        vaesef.vs       \data, v13
.else
        vaesem.vs       \data, v11
        vaesem.vs       \data, v12
        vaesem.vs       \data, v13
        vaesem.vs       \data, v14
        vaesef.vs       \data, v15
.endif
.endm

// Same as aes_encrypt, but decrypts instead of encrypts.
.macro  aes_decrypt     data, keylen
.if \keylen == 128
        vaesz.vs        \data, v11
.elseif \keylen == 192
        vaesz.vs        \data, v13
        vaesdm.vs       \data, v12
        vaesdm.vs       \data, v11
.else
        vaesz.vs        \data, v15
        vaesdm.vs       \data, v14
        vaesdm.vs       \data, v13
        vaesdm.vs       \data, v12
        vaesdm.vs       \data, v11
.endif
        vaesdm.vs       \data, v10
        vaesdm.vs       \data, v9
        vaesdm.vs       \data, v8
        vaesdm.vs       \data, v7
        vaesdm.vs       \data, v6
        vaesdm.vs       \data, v5
        vaesdm.vs       \data, v4
        vaesdm.vs       \data, v3
        vaesdm.vs       \data, v2
        vaesdf.vs       \data, v1
.endm

// Expands to aes_encrypt or aes_decrypt according to \enc, which is 1 or 0.
.macro  aes_crypt       data, enc, keylen
.if \enc
        aes_encrypt     \data, \keylen
.else
        aes_decrypt     \data, \keylen
.endif
.endm