1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * The AEGIS-128 Authenticated-Encryption Algorithm
4 * Glue for AES-NI + SSE4.1 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
26 struct aegis_block {
27 u8 bytes[AEGIS128_BLOCK_SIZE] __aligned(AEGIS128_BLOCK_ALIGN);
28 };
29
30 struct aegis_state {
31 struct aegis_block blocks[AEGIS128_STATE_BLOCKS];
32 };
33
34 struct aegis_ctx {
35 struct aegis_block key;
36 };
37
38 asmlinkage void aegis128_aesni_init(struct aegis_state *state,
39 const struct aegis_block *key,
40 const u8 iv[AEGIS128_NONCE_SIZE]);
41
42 asmlinkage void aegis128_aesni_ad(struct aegis_state *state, const u8 *data,
43 unsigned int len);
44
45 asmlinkage void aegis128_aesni_enc(struct aegis_state *state, const u8 *src,
46 u8 *dst, unsigned int len);
47
48 asmlinkage void aegis128_aesni_dec(struct aegis_state *state, const u8 *src,
49 u8 *dst, unsigned int len);
50
51 asmlinkage void aegis128_aesni_enc_tail(struct aegis_state *state,
52 const u8 *src, u8 *dst,
53 unsigned int len);
54
55 asmlinkage void aegis128_aesni_dec_tail(struct aegis_state *state,
56 const u8 *src, u8 *dst,
57 unsigned int len);
58
59 asmlinkage void aegis128_aesni_final(struct aegis_state *state,
60 struct aegis_block *tag_xor,
61 unsigned int assoclen,
62 unsigned int cryptlen);
63
crypto_aegis128_aesni_process_ad(struct aegis_state * state,struct scatterlist * sg_src,unsigned int assoclen)64 static void crypto_aegis128_aesni_process_ad(
65 struct aegis_state *state, struct scatterlist *sg_src,
66 unsigned int assoclen)
67 {
68 struct scatter_walk walk;
69 struct aegis_block buf;
70 unsigned int pos = 0;
71
72 scatterwalk_start(&walk, sg_src);
73 while (assoclen != 0) {
74 unsigned int size = scatterwalk_next(&walk, assoclen);
75 const u8 *src = walk.addr;
76 unsigned int left = size;
77
78 if (pos + size >= AEGIS128_BLOCK_SIZE) {
79 if (pos > 0) {
80 unsigned int fill = AEGIS128_BLOCK_SIZE - pos;
81 memcpy(buf.bytes + pos, src, fill);
82 aegis128_aesni_ad(state, buf.bytes,
83 AEGIS128_BLOCK_SIZE);
84 pos = 0;
85 left -= fill;
86 src += fill;
87 }
88
89 aegis128_aesni_ad(state, src,
90 left & ~(AEGIS128_BLOCK_SIZE - 1));
91 src += left & ~(AEGIS128_BLOCK_SIZE - 1);
92 left &= AEGIS128_BLOCK_SIZE - 1;
93 }
94
95 memcpy(buf.bytes + pos, src, left);
96 pos += left;
97 assoclen -= size;
98
99 scatterwalk_done_src(&walk, size);
100 }
101
102 if (pos > 0) {
103 memset(buf.bytes + pos, 0, AEGIS128_BLOCK_SIZE - pos);
104 aegis128_aesni_ad(state, buf.bytes, AEGIS128_BLOCK_SIZE);
105 }
106 }
107
108 static __always_inline void
crypto_aegis128_aesni_process_crypt(struct aegis_state * state,struct skcipher_walk * walk,bool enc)109 crypto_aegis128_aesni_process_crypt(struct aegis_state *state,
110 struct skcipher_walk *walk, bool enc)
111 {
112 while (walk->nbytes >= AEGIS128_BLOCK_SIZE) {
113 if (enc)
114 aegis128_aesni_enc(state, walk->src.virt.addr,
115 walk->dst.virt.addr,
116 round_down(walk->nbytes,
117 AEGIS128_BLOCK_SIZE));
118 else
119 aegis128_aesni_dec(state, walk->src.virt.addr,
120 walk->dst.virt.addr,
121 round_down(walk->nbytes,
122 AEGIS128_BLOCK_SIZE));
123 skcipher_walk_done(walk, walk->nbytes % AEGIS128_BLOCK_SIZE);
124 }
125
126 if (walk->nbytes) {
127 if (enc)
128 aegis128_aesni_enc_tail(state, walk->src.virt.addr,
129 walk->dst.virt.addr,
130 walk->nbytes);
131 else
132 aegis128_aesni_dec_tail(state, walk->src.virt.addr,
133 walk->dst.virt.addr,
134 walk->nbytes);
135 skcipher_walk_done(walk, 0);
136 }
137 }
138
crypto_aegis128_aesni_ctx(struct crypto_aead * aead)139 static struct aegis_ctx *crypto_aegis128_aesni_ctx(struct crypto_aead *aead)
140 {
141 u8 *ctx = crypto_aead_ctx(aead);
142 ctx = PTR_ALIGN(ctx, __alignof__(struct aegis_ctx));
143 return (void *)ctx;
144 }
145
crypto_aegis128_aesni_setkey(struct crypto_aead * aead,const u8 * key,unsigned int keylen)146 static int crypto_aegis128_aesni_setkey(struct crypto_aead *aead, const u8 *key,
147 unsigned int keylen)
148 {
149 struct aegis_ctx *ctx = crypto_aegis128_aesni_ctx(aead);
150
151 if (keylen != AEGIS128_KEY_SIZE)
152 return -EINVAL;
153
154 memcpy(ctx->key.bytes, key, AEGIS128_KEY_SIZE);
155
156 return 0;
157 }
158
crypto_aegis128_aesni_setauthsize(struct crypto_aead * tfm,unsigned int authsize)159 static int crypto_aegis128_aesni_setauthsize(struct crypto_aead *tfm,
160 unsigned int authsize)
161 {
162 if (authsize > AEGIS128_MAX_AUTH_SIZE)
163 return -EINVAL;
164 if (authsize < AEGIS128_MIN_AUTH_SIZE)
165 return -EINVAL;
166 return 0;
167 }
168
169 static __always_inline void
crypto_aegis128_aesni_crypt(struct aead_request * req,struct aegis_block * tag_xor,unsigned int cryptlen,bool enc)170 crypto_aegis128_aesni_crypt(struct aead_request *req,
171 struct aegis_block *tag_xor,
172 unsigned int cryptlen, bool enc)
173 {
174 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
175 struct aegis_ctx *ctx = crypto_aegis128_aesni_ctx(tfm);
176 struct skcipher_walk walk;
177 struct aegis_state state;
178
179 if (enc)
180 skcipher_walk_aead_encrypt(&walk, req, true);
181 else
182 skcipher_walk_aead_decrypt(&walk, req, true);
183
184 kernel_fpu_begin();
185
186 aegis128_aesni_init(&state, &ctx->key, req->iv);
187 crypto_aegis128_aesni_process_ad(&state, req->src, req->assoclen);
188 crypto_aegis128_aesni_process_crypt(&state, &walk, enc);
189 aegis128_aesni_final(&state, tag_xor, req->assoclen, cryptlen);
190
191 kernel_fpu_end();
192 }
193
crypto_aegis128_aesni_encrypt(struct aead_request * req)194 static int crypto_aegis128_aesni_encrypt(struct aead_request *req)
195 {
196 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
197 struct aegis_block tag = {};
198 unsigned int authsize = crypto_aead_authsize(tfm);
199 unsigned int cryptlen = req->cryptlen;
200
201 crypto_aegis128_aesni_crypt(req, &tag, cryptlen, true);
202
203 scatterwalk_map_and_copy(tag.bytes, req->dst,
204 req->assoclen + cryptlen, authsize, 1);
205 return 0;
206 }
207
crypto_aegis128_aesni_decrypt(struct aead_request * req)208 static int crypto_aegis128_aesni_decrypt(struct aead_request *req)
209 {
210 static const struct aegis_block zeros = {};
211
212 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
213 struct aegis_block tag;
214 unsigned int authsize = crypto_aead_authsize(tfm);
215 unsigned int cryptlen = req->cryptlen - authsize;
216
217 scatterwalk_map_and_copy(tag.bytes, req->src,
218 req->assoclen + cryptlen, authsize, 0);
219
220 crypto_aegis128_aesni_crypt(req, &tag, cryptlen, false);
221
222 return crypto_memneq(tag.bytes, zeros.bytes, authsize) ? -EBADMSG : 0;
223 }
224
225 static struct aead_alg crypto_aegis128_aesni_alg = {
226 .setkey = crypto_aegis128_aesni_setkey,
227 .setauthsize = crypto_aegis128_aesni_setauthsize,
228 .encrypt = crypto_aegis128_aesni_encrypt,
229 .decrypt = crypto_aegis128_aesni_decrypt,
230
231 .ivsize = AEGIS128_NONCE_SIZE,
232 .maxauthsize = AEGIS128_MAX_AUTH_SIZE,
233 .chunksize = AEGIS128_BLOCK_SIZE,
234
235 .base = {
236 .cra_flags = CRYPTO_ALG_INTERNAL,
237 .cra_blocksize = 1,
238 .cra_ctxsize = sizeof(struct aegis_ctx) +
239 __alignof__(struct aegis_ctx),
240 .cra_priority = 400,
241
242 .cra_name = "__aegis128",
243 .cra_driver_name = "__aegis128-aesni",
244
245 .cra_module = THIS_MODULE,
246 }
247 };
248
249 static struct simd_aead_alg *simd_alg;
250
crypto_aegis128_aesni_module_init(void)251 static int __init crypto_aegis128_aesni_module_init(void)
252 {
253 if (!boot_cpu_has(X86_FEATURE_XMM4_1) ||
254 !boot_cpu_has(X86_FEATURE_AES) ||
255 !cpu_has_xfeatures(XFEATURE_MASK_SSE, NULL))
256 return -ENODEV;
257
258 return simd_register_aeads_compat(&crypto_aegis128_aesni_alg, 1,
259 &simd_alg);
260 }
261
crypto_aegis128_aesni_module_exit(void)262 static void __exit crypto_aegis128_aesni_module_exit(void)
263 {
264 simd_unregister_aeads(&crypto_aegis128_aesni_alg, 1, &simd_alg);
265 }
266
267 module_init(crypto_aegis128_aesni_module_init);
268 module_exit(crypto_aegis128_aesni_module_exit);
269
270 MODULE_LICENSE("GPL");
271 MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
272 MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm -- AESNI+SSE4.1 implementation");
273 MODULE_ALIAS_CRYPTO("aegis128");
274 MODULE_ALIAS_CRYPTO("aegis128-aesni");
275