1 // SPDX-License-Identifier: GPL-2.0-only 1 // SPDX-License-Identifier: GPL-2.0-only
2 /* 2 /*
3 * Scalar fixed time AES core transform 3 * Scalar fixed time AES core transform
4 * 4 *
5 * Copyright (C) 2017 Linaro Ltd <ard.biesheuv 5 * Copyright (C) 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
6 */ 6 */
7 7
8 #include <crypto/aes.h> 8 #include <crypto/aes.h>
9 #include <crypto/algapi.h> 9 #include <crypto/algapi.h>
10 #include <linux/module.h> 10 #include <linux/module.h>
11 11
12 static int aesti_set_key(struct crypto_tfm *tf 12 static int aesti_set_key(struct crypto_tfm *tfm, const u8 *in_key,
13 unsigned int key_len) 13 unsigned int key_len)
14 { 14 {
15 struct crypto_aes_ctx *ctx = crypto_tf 15 struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
16 16
17 return aes_expandkey(ctx, in_key, key_ 17 return aes_expandkey(ctx, in_key, key_len);
18 } 18 }
19 19
20 static void aesti_encrypt(struct crypto_tfm *t 20 static void aesti_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
21 { 21 {
22 const struct crypto_aes_ctx *ctx = cry 22 const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
23 unsigned long flags; 23 unsigned long flags;
24 24
25 /* 25 /*
26 * Temporarily disable interrupts to a 26 * Temporarily disable interrupts to avoid races where cachelines are
27 * evicted when the CPU is interrupted 27 * evicted when the CPU is interrupted to do something else.
28 */ 28 */
29 local_irq_save(flags); 29 local_irq_save(flags);
30 30
31 aes_encrypt(ctx, out, in); 31 aes_encrypt(ctx, out, in);
32 32
33 local_irq_restore(flags); 33 local_irq_restore(flags);
34 } 34 }
35 35
36 static void aesti_decrypt(struct crypto_tfm *t 36 static void aesti_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
37 { 37 {
38 const struct crypto_aes_ctx *ctx = cry 38 const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
39 unsigned long flags; 39 unsigned long flags;
40 40
41 /* 41 /*
42 * Temporarily disable interrupts to a 42 * Temporarily disable interrupts to avoid races where cachelines are
43 * evicted when the CPU is interrupted 43 * evicted when the CPU is interrupted to do something else.
44 */ 44 */
45 local_irq_save(flags); 45 local_irq_save(flags);
46 46
47 aes_decrypt(ctx, out, in); 47 aes_decrypt(ctx, out, in);
48 48
49 local_irq_restore(flags); 49 local_irq_restore(flags);
50 } 50 }
51 51
52 static struct crypto_alg aes_alg = { 52 static struct crypto_alg aes_alg = {
53 .cra_name = "aes 53 .cra_name = "aes",
54 .cra_driver_name = "aes 54 .cra_driver_name = "aes-fixed-time",
55 .cra_priority = 100 55 .cra_priority = 100 + 1,
56 .cra_flags = CRYP 56 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
57 .cra_blocksize = AES_ 57 .cra_blocksize = AES_BLOCK_SIZE,
58 .cra_ctxsize = size 58 .cra_ctxsize = sizeof(struct crypto_aes_ctx),
59 .cra_module = THIS 59 .cra_module = THIS_MODULE,
60 60
61 .cra_cipher.cia_min_keysize = AES_ 61 .cra_cipher.cia_min_keysize = AES_MIN_KEY_SIZE,
62 .cra_cipher.cia_max_keysize = AES_ 62 .cra_cipher.cia_max_keysize = AES_MAX_KEY_SIZE,
63 .cra_cipher.cia_setkey = aest 63 .cra_cipher.cia_setkey = aesti_set_key,
64 .cra_cipher.cia_encrypt = aest 64 .cra_cipher.cia_encrypt = aesti_encrypt,
65 .cra_cipher.cia_decrypt = aest 65 .cra_cipher.cia_decrypt = aesti_decrypt
66 }; 66 };
67 67
68 static int __init aes_init(void) 68 static int __init aes_init(void)
69 { 69 {
70 return crypto_register_alg(&aes_alg); 70 return crypto_register_alg(&aes_alg);
71 } 71 }
72 72
73 static void __exit aes_fini(void) 73 static void __exit aes_fini(void)
74 { 74 {
75 crypto_unregister_alg(&aes_alg); 75 crypto_unregister_alg(&aes_alg);
76 } 76 }
77 77
78 module_init(aes_init); 78 module_init(aes_init);
79 module_exit(aes_fini); 79 module_exit(aes_fini);
80 80
81 MODULE_DESCRIPTION("Generic fixed time AES"); 81 MODULE_DESCRIPTION("Generic fixed time AES");
82 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@ 82 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
83 MODULE_LICENSE("GPL v2"); 83 MODULE_LICENSE("GPL v2");
84 84
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