1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * The AEGIS-128 Authenticated-Encryption Algorithm
4 *   Glue for AES-NI + SSE2 implementation
5 *
6 * Copyright (c) 2017-2018 Ondrej Mosnacek <omosnacek@gmail.com>
7 * Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
8 */
9
10#include <crypto/internal/aead.h>
11#include <crypto/internal/simd.h>
12#include <crypto/internal/skcipher.h>
13#include <crypto/scatterwalk.h>
14#include <linux/module.h>
15#include <asm/fpu/api.h>
16#include <asm/cpu_device_id.h>
17
18#define AEGIS128_BLOCK_ALIGN 16
19#define AEGIS128_BLOCK_SIZE 16
20#define AEGIS128_NONCE_SIZE 16
21#define AEGIS128_STATE_BLOCKS 5
22#define AEGIS128_KEY_SIZE 16
23#define AEGIS128_MIN_AUTH_SIZE 8
24#define AEGIS128_MAX_AUTH_SIZE 16
25
26asmlinkage void crypto_aegis128_aesni_init(void *state, void *key, void *iv);
27
28asmlinkage void crypto_aegis128_aesni_ad(
29		void *state, unsigned int length, const void *data);
30
31asmlinkage void crypto_aegis128_aesni_enc(
32		void *state, unsigned int length, const void *src, void *dst);
33
34asmlinkage void crypto_aegis128_aesni_dec(
35		void *state, unsigned int length, const void *src, void *dst);
36
37asmlinkage void crypto_aegis128_aesni_enc_tail(
38		void *state, unsigned int length, const void *src, void *dst);
39
40asmlinkage void crypto_aegis128_aesni_dec_tail(
41		void *state, unsigned int length, const void *src, void *dst);
42
43asmlinkage void crypto_aegis128_aesni_final(
44		void *state, void *tag_xor, unsigned int cryptlen,
45		unsigned int assoclen);
46
47struct aegis_block {
48	u8 bytes[AEGIS128_BLOCK_SIZE] __aligned(AEGIS128_BLOCK_ALIGN);
49};
50
51struct aegis_state {
52	struct aegis_block blocks[AEGIS128_STATE_BLOCKS];
53};
54
55struct aegis_ctx {
56	struct aegis_block key;
57};
58
59struct aegis_crypt_ops {
60	int (*skcipher_walk_init)(struct skcipher_walk *walk,
61				  struct aead_request *req, bool atomic);
62
63	void (*crypt_blocks)(void *state, unsigned int length, const void *src,
64			     void *dst);
65	void (*crypt_tail)(void *state, unsigned int length, const void *src,
66			   void *dst);
67};
68
69static void crypto_aegis128_aesni_process_ad(
70		struct aegis_state *state, struct scatterlist *sg_src,
71		unsigned int assoclen)
72{
73	struct scatter_walk walk;
74	struct aegis_block buf;
75	unsigned int pos = 0;
76
77	scatterwalk_start(&walk, sg_src);
78	while (assoclen != 0) {
79		unsigned int size = scatterwalk_clamp(&walk, assoclen);
80		unsigned int left = size;
81		void *mapped = scatterwalk_map(&walk);
82		const u8 *src = (const u8 *)mapped;
83
84		if (pos + size >= AEGIS128_BLOCK_SIZE) {
85			if (pos > 0) {
86				unsigned int fill = AEGIS128_BLOCK_SIZE - pos;
87				memcpy(buf.bytes + pos, src, fill);
88				crypto_aegis128_aesni_ad(state,
89							 AEGIS128_BLOCK_SIZE,
90							 buf.bytes);
91				pos = 0;
92				left -= fill;
93				src += fill;
94			}
95
96			crypto_aegis128_aesni_ad(state, left, src);
97
98			src += left & ~(AEGIS128_BLOCK_SIZE - 1);
99			left &= AEGIS128_BLOCK_SIZE - 1;
100		}
101
102		memcpy(buf.bytes + pos, src, left);
103		pos += left;
104		assoclen -= size;
105
106		scatterwalk_unmap(mapped);
107		scatterwalk_advance(&walk, size);
108		scatterwalk_done(&walk, 0, assoclen);
109	}
110
111	if (pos > 0) {
112		memset(buf.bytes + pos, 0, AEGIS128_BLOCK_SIZE - pos);
113		crypto_aegis128_aesni_ad(state, AEGIS128_BLOCK_SIZE, buf.bytes);
114	}
115}
116
117static void crypto_aegis128_aesni_process_crypt(
118		struct aegis_state *state, struct skcipher_walk *walk,
119		const struct aegis_crypt_ops *ops)
120{
121	while (walk->nbytes >= AEGIS128_BLOCK_SIZE) {
122		ops->crypt_blocks(state,
123				  round_down(walk->nbytes, AEGIS128_BLOCK_SIZE),
124				  walk->src.virt.addr, walk->dst.virt.addr);
125		skcipher_walk_done(walk, walk->nbytes % AEGIS128_BLOCK_SIZE);
126	}
127
128	if (walk->nbytes) {
129		ops->crypt_tail(state, walk->nbytes, walk->src.virt.addr,
130				walk->dst.virt.addr);
131		skcipher_walk_done(walk, 0);
132	}
133}
134
135static struct aegis_ctx *crypto_aegis128_aesni_ctx(struct crypto_aead *aead)
136{
137	u8 *ctx = crypto_aead_ctx(aead);
138	ctx = PTR_ALIGN(ctx, __alignof__(struct aegis_ctx));
139	return (void *)ctx;
140}
141
142static int crypto_aegis128_aesni_setkey(struct crypto_aead *aead, const u8 *key,
143					unsigned int keylen)
144{
145	struct aegis_ctx *ctx = crypto_aegis128_aesni_ctx(aead);
146
147	if (keylen != AEGIS128_KEY_SIZE)
148		return -EINVAL;
149
150	memcpy(ctx->key.bytes, key, AEGIS128_KEY_SIZE);
151
152	return 0;
153}
154
155static int crypto_aegis128_aesni_setauthsize(struct crypto_aead *tfm,
156						unsigned int authsize)
157{
158	if (authsize > AEGIS128_MAX_AUTH_SIZE)
159		return -EINVAL;
160	if (authsize < AEGIS128_MIN_AUTH_SIZE)
161		return -EINVAL;
162	return 0;
163}
164
165static void crypto_aegis128_aesni_crypt(struct aead_request *req,
166					struct aegis_block *tag_xor,
167					unsigned int cryptlen,
168					const struct aegis_crypt_ops *ops)
169{
170	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
171	struct aegis_ctx *ctx = crypto_aegis128_aesni_ctx(tfm);
172	struct skcipher_walk walk;
173	struct aegis_state state;
174
175	ops->skcipher_walk_init(&walk, req, true);
176
177	kernel_fpu_begin();
178
179	crypto_aegis128_aesni_init(&state, ctx->key.bytes, req->iv);
180	crypto_aegis128_aesni_process_ad(&state, req->src, req->assoclen);
181	crypto_aegis128_aesni_process_crypt(&state, &walk, ops);
182	crypto_aegis128_aesni_final(&state, tag_xor, req->assoclen, cryptlen);
183
184	kernel_fpu_end();
185}
186
187static int crypto_aegis128_aesni_encrypt(struct aead_request *req)
188{
189	static const struct aegis_crypt_ops OPS = {
190		.skcipher_walk_init = skcipher_walk_aead_encrypt,
191		.crypt_blocks = crypto_aegis128_aesni_enc,
192		.crypt_tail = crypto_aegis128_aesni_enc_tail,
193	};
194
195	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
196	struct aegis_block tag = {};
197	unsigned int authsize = crypto_aead_authsize(tfm);
198	unsigned int cryptlen = req->cryptlen;
199
200	crypto_aegis128_aesni_crypt(req, &tag, cryptlen, &OPS);
201
202	scatterwalk_map_and_copy(tag.bytes, req->dst,
203				 req->assoclen + cryptlen, authsize, 1);
204	return 0;
205}
206
207static int crypto_aegis128_aesni_decrypt(struct aead_request *req)
208{
209	static const struct aegis_block zeros = {};
210
211	static const struct aegis_crypt_ops OPS = {
212		.skcipher_walk_init = skcipher_walk_aead_decrypt,
213		.crypt_blocks = crypto_aegis128_aesni_dec,
214		.crypt_tail = crypto_aegis128_aesni_dec_tail,
215	};
216
217	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
218	struct aegis_block tag;
219	unsigned int authsize = crypto_aead_authsize(tfm);
220	unsigned int cryptlen = req->cryptlen - authsize;
221
222	scatterwalk_map_and_copy(tag.bytes, req->src,
223				 req->assoclen + cryptlen, authsize, 0);
224
225	crypto_aegis128_aesni_crypt(req, &tag, cryptlen, &OPS);
226
227	return crypto_memneq(tag.bytes, zeros.bytes, authsize) ? -EBADMSG : 0;
228}
229
230static int crypto_aegis128_aesni_init_tfm(struct crypto_aead *aead)
231{
232	return 0;
233}
234
235static void crypto_aegis128_aesni_exit_tfm(struct crypto_aead *aead)
236{
237}
238
239static struct aead_alg crypto_aegis128_aesni_alg = {
240	.setkey = crypto_aegis128_aesni_setkey,
241	.setauthsize = crypto_aegis128_aesni_setauthsize,
242	.encrypt = crypto_aegis128_aesni_encrypt,
243	.decrypt = crypto_aegis128_aesni_decrypt,
244	.init = crypto_aegis128_aesni_init_tfm,
245	.exit = crypto_aegis128_aesni_exit_tfm,
246
247	.ivsize = AEGIS128_NONCE_SIZE,
248	.maxauthsize = AEGIS128_MAX_AUTH_SIZE,
249	.chunksize = AEGIS128_BLOCK_SIZE,
250
251	.base = {
252		.cra_flags = CRYPTO_ALG_INTERNAL,
253		.cra_blocksize = 1,
254		.cra_ctxsize = sizeof(struct aegis_ctx) +
255			       __alignof__(struct aegis_ctx),
256		.cra_alignmask = 0,
257		.cra_priority = 400,
258
259		.cra_name = "__aegis128",
260		.cra_driver_name = "__aegis128-aesni",
261
262		.cra_module = THIS_MODULE,
263	}
264};
265
266static struct simd_aead_alg *simd_alg;
267
268static int __init crypto_aegis128_aesni_module_init(void)
269{
270	if (!boot_cpu_has(X86_FEATURE_XMM2) ||
271	    !boot_cpu_has(X86_FEATURE_AES) ||
272	    !cpu_has_xfeatures(XFEATURE_MASK_SSE, NULL))
273		return -ENODEV;
274
275	return simd_register_aeads_compat(&crypto_aegis128_aesni_alg, 1,
276					  &simd_alg);
277}
278
279static void __exit crypto_aegis128_aesni_module_exit(void)
280{
281	simd_unregister_aeads(&crypto_aegis128_aesni_alg, 1, &simd_alg);
282}
283
284module_init(crypto_aegis128_aesni_module_init);
285module_exit(crypto_aegis128_aesni_module_exit);
286
287MODULE_LICENSE("GPL");
288MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
289MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm -- AESNI+SSE2 implementation");
290MODULE_ALIAS_CRYPTO("aegis128");
291MODULE_ALIAS_CRYPTO("aegis128-aesni");
292