// SPDX-License-Identifier: GPL-2.0-only /* * Scalar fixed time AES core transform * * Copyright (C) 2017 Linaro Ltd <ard.biesheuvel@linaro.org> */ #include <crypto/aes.h> #include <linux/crypto.h> #include <linux/module.h> static int aesti_set_key(struct crypto_tfm *tfm, const u8 *in_key, unsigned int key_len) { struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm); return aes_expandkey(ctx, in_key, key_len); } static void aesti_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) { const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm); unsigned long flags; /* * Temporarily disable interrupts to avoid races where cachelines are * evicted when the CPU is interrupted to do something else. */ local_irq_save(flags); aes_encrypt(ctx, out, in); local_irq_restore(flags); } static void aesti_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) { const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm); unsigned long flags; /* * Temporarily disable interrupts to avoid races where cachelines are * evicted when the CPU is interrupted to do something else. */ local_irq_save(flags); aes_decrypt(ctx, out, in); local_irq_restore(flags); } static struct crypto_alg aes_alg = { .cra_name = "aes", .cra_driver_name = "aes-fixed-time", .cra_priority = 100 + 1, .cra_flags = CRYPTO_ALG_TYPE_CIPHER, .cra_blocksize = AES_BLOCK_SIZE, .cra_ctxsize = sizeof(struct crypto_aes_ctx), .cra_module = THIS_MODULE, .cra_cipher.cia_min_keysize = AES_MIN_KEY_SIZE, .cra_cipher.cia_max_keysize = AES_MAX_KEY_SIZE, .cra_cipher.cia_setkey = aesti_set_key, .cra_cipher.cia_encrypt = aesti_encrypt, .cra_cipher.cia_decrypt = aesti_decrypt }; static int __init aes_init(void) { return crypto_register_alg(&aes_alg); } static void __exit aes_fini(void) { crypto_unregister_alg(&aes_alg); } module_init(aes_init); module_exit(aes_fini); MODULE_DESCRIPTION("Generic fixed time AES"); MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); MODULE_LICENSE("GPL v2");