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