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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Scalar fixed time AES core transform4 *5 * Copyright (C) 2017 Linaro Ltd <ard.biesheuvel@linaro.org>6 */7 8#include <crypto/aes.h>9#include <crypto/algapi.h>10#include <linux/module.h>11 12static int aesti_set_key(struct crypto_tfm *tfm, const u8 *in_key,13 unsigned int key_len)14{15 struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);16 17 return aes_expandkey(ctx, in_key, key_len);18}19 20static void aesti_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)21{22 const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);23 unsigned long flags;24 25 /*26 * Temporarily disable interrupts to avoid races where cachelines are27 * evicted when the CPU is interrupted to do something else.28 */29 local_irq_save(flags);30 31 aes_encrypt(ctx, out, in);32 33 local_irq_restore(flags);34}35 36static void aesti_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)37{38 const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);39 unsigned long flags;40 41 /*42 * Temporarily disable interrupts to avoid races where cachelines are43 * evicted when the CPU is interrupted to do something else.44 */45 local_irq_save(flags);46 47 aes_decrypt(ctx, out, in);48 49 local_irq_restore(flags);50}51 52static struct crypto_alg aes_alg = {53 .cra_name = "aes",54 .cra_driver_name = "aes-fixed-time",55 .cra_priority = 100 + 1,56 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,57 .cra_blocksize = AES_BLOCK_SIZE,58 .cra_ctxsize = sizeof(struct crypto_aes_ctx),59 .cra_module = THIS_MODULE,60 61 .cra_cipher.cia_min_keysize = AES_MIN_KEY_SIZE,62 .cra_cipher.cia_max_keysize = AES_MAX_KEY_SIZE,63 .cra_cipher.cia_setkey = aesti_set_key,64 .cra_cipher.cia_encrypt = aesti_encrypt,65 .cra_cipher.cia_decrypt = aesti_decrypt66};67 68static int __init aes_init(void)69{70 return crypto_register_alg(&aes_alg);71}72 73static void __exit aes_fini(void)74{75 crypto_unregister_alg(&aes_alg);76}77 78module_init(aes_init);79module_exit(aes_fini);80 81MODULE_DESCRIPTION("Generic fixed time AES");82MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");83MODULE_LICENSE("GPL v2");84