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/skcipher.h> 12 #include <crypto/scatterwalk.h> 13 #include <linux/module.h> 14 #include <asm/fpu/api.h> 15 #include <asm/cpu_device_id.h> 16 17 #define AEGIS128_BLOCK_ALIGN 16 18 #define AEGIS128_BLOCK_SIZE 16 19 #define AEGIS128_NONCE_SIZE 16 20 #define AEGIS128_STATE_BLOCKS 5 21 #define AEGIS128_KEY_SIZE 16 22 #define AEGIS128_MIN_AUTH_SIZE 8 23 #define AEGIS128_MAX_AUTH_SIZE 16 24 25 struct aegis_block { 26 u8 bytes[AEGIS128_BLOCK_SIZE] __aligned(AEGIS128_BLOCK_ALIGN); 27 }; 28 29 struct aegis_state { 30 struct aegis_block blocks[AEGIS128_STATE_BLOCKS]; 31 }; 32 33 struct aegis_ctx { 34 struct aegis_block key; 35 }; 36 37 asmlinkage void aegis128_aesni_init(struct aegis_state *state, 38 const struct aegis_block *key, 39 const u8 iv[AEGIS128_NONCE_SIZE]); 40 41 asmlinkage void aegis128_aesni_ad(struct aegis_state *state, const u8 *data, 42 unsigned int len); 43 44 asmlinkage void aegis128_aesni_enc(struct aegis_state *state, const u8 *src, 45 u8 *dst, unsigned int len); 46 47 asmlinkage void aegis128_aesni_dec(struct aegis_state *state, const u8 *src, 48 u8 *dst, unsigned int len); 49 50 asmlinkage void aegis128_aesni_enc_tail(struct aegis_state *state, 51 const u8 *src, u8 *dst, 52 unsigned int len); 53 54 asmlinkage void aegis128_aesni_dec_tail(struct aegis_state *state, 55 const u8 *src, u8 *dst, 56 unsigned int len); 57 58 asmlinkage void aegis128_aesni_final(struct aegis_state *state, 59 struct aegis_block *tag_xor, 60 unsigned int assoclen, 61 unsigned int cryptlen); 62 63 static void crypto_aegis128_aesni_process_ad( 64 struct aegis_state *state, struct scatterlist *sg_src, 65 unsigned int assoclen) 66 { 67 struct scatter_walk walk; 68 struct aegis_block buf; 69 unsigned int pos = 0; 70 71 scatterwalk_start(&walk, sg_src); 72 while (assoclen != 0) { 73 unsigned int size = scatterwalk_next(&walk, assoclen); 74 const u8 *src = walk.addr; 75 unsigned int left = size; 76 77 if (pos + size >= AEGIS128_BLOCK_SIZE) { 78 if (pos > 0) { 79 unsigned int fill = AEGIS128_BLOCK_SIZE - pos; 80 memcpy(buf.bytes + pos, src, fill); 81 aegis128_aesni_ad(state, buf.bytes, 82 AEGIS128_BLOCK_SIZE); 83 pos = 0; 84 left -= fill; 85 src += fill; 86 } 87 88 aegis128_aesni_ad(state, src, 89 left & ~(AEGIS128_BLOCK_SIZE - 1)); 90 src += left & ~(AEGIS128_BLOCK_SIZE - 1); 91 left &= AEGIS128_BLOCK_SIZE - 1; 92 } 93 94 memcpy(buf.bytes + pos, src, left); 95 pos += left; 96 assoclen -= size; 97 98 scatterwalk_done_src(&walk, size); 99 } 100 101 if (pos > 0) { 102 memset(buf.bytes + pos, 0, AEGIS128_BLOCK_SIZE - pos); 103 aegis128_aesni_ad(state, buf.bytes, AEGIS128_BLOCK_SIZE); 104 } 105 } 106 107 static __always_inline int 108 crypto_aegis128_aesni_process_crypt(struct aegis_state *state, 109 struct skcipher_walk *walk, bool enc) 110 { 111 int err = 0; 112 113 while (walk->nbytes >= AEGIS128_BLOCK_SIZE) { 114 if (enc) 115 aegis128_aesni_enc(state, walk->src.virt.addr, 116 walk->dst.virt.addr, 117 round_down(walk->nbytes, 118 AEGIS128_BLOCK_SIZE)); 119 else 120 aegis128_aesni_dec(state, walk->src.virt.addr, 121 walk->dst.virt.addr, 122 round_down(walk->nbytes, 123 AEGIS128_BLOCK_SIZE)); 124 kernel_fpu_end(); 125 err = skcipher_walk_done(walk, 126 walk->nbytes % AEGIS128_BLOCK_SIZE); 127 kernel_fpu_begin(); 128 } 129 130 if (walk->nbytes) { 131 if (enc) 132 aegis128_aesni_enc_tail(state, walk->src.virt.addr, 133 walk->dst.virt.addr, 134 walk->nbytes); 135 else 136 aegis128_aesni_dec_tail(state, walk->src.virt.addr, 137 walk->dst.virt.addr, 138 walk->nbytes); 139 kernel_fpu_end(); 140 err = skcipher_walk_done(walk, 0); 141 kernel_fpu_begin(); 142 } 143 return err; 144 } 145 146 static struct aegis_ctx *crypto_aegis128_aesni_ctx(struct crypto_aead *aead) 147 { 148 u8 *ctx = crypto_aead_ctx(aead); 149 ctx = PTR_ALIGN(ctx, __alignof__(struct aegis_ctx)); 150 return (void *)ctx; 151 } 152 153 static int crypto_aegis128_aesni_setkey(struct crypto_aead *aead, const u8 *key, 154 unsigned int keylen) 155 { 156 struct aegis_ctx *ctx = crypto_aegis128_aesni_ctx(aead); 157 158 if (keylen != AEGIS128_KEY_SIZE) 159 return -EINVAL; 160 161 memcpy(ctx->key.bytes, key, AEGIS128_KEY_SIZE); 162 163 return 0; 164 } 165 166 static int crypto_aegis128_aesni_setauthsize(struct crypto_aead *tfm, 167 unsigned int authsize) 168 { 169 if (authsize > AEGIS128_MAX_AUTH_SIZE) 170 return -EINVAL; 171 if (authsize < AEGIS128_MIN_AUTH_SIZE) 172 return -EINVAL; 173 return 0; 174 } 175 176 static __always_inline int 177 crypto_aegis128_aesni_crypt(struct aead_request *req, 178 struct aegis_block *tag_xor, 179 unsigned int cryptlen, bool enc) 180 { 181 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 182 struct aegis_ctx *ctx = crypto_aegis128_aesni_ctx(tfm); 183 struct skcipher_walk walk; 184 struct aegis_state state; 185 int err; 186 187 if (enc) 188 err = skcipher_walk_aead_encrypt(&walk, req, false); 189 else 190 err = skcipher_walk_aead_decrypt(&walk, req, false); 191 if (err) 192 return err; 193 194 kernel_fpu_begin(); 195 196 aegis128_aesni_init(&state, &ctx->key, req->iv); 197 crypto_aegis128_aesni_process_ad(&state, req->src, req->assoclen); 198 err = crypto_aegis128_aesni_process_crypt(&state, &walk, enc); 199 if (err == 0) 200 aegis128_aesni_final(&state, tag_xor, req->assoclen, cryptlen); 201 kernel_fpu_end(); 202 return err; 203 } 204 205 static int crypto_aegis128_aesni_encrypt(struct aead_request *req) 206 { 207 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 208 struct aegis_block tag = {}; 209 unsigned int authsize = crypto_aead_authsize(tfm); 210 unsigned int cryptlen = req->cryptlen; 211 int err; 212 213 err = crypto_aegis128_aesni_crypt(req, &tag, cryptlen, true); 214 if (err) 215 return err; 216 217 scatterwalk_map_and_copy(tag.bytes, req->dst, 218 req->assoclen + cryptlen, authsize, 1); 219 return 0; 220 } 221 222 static int crypto_aegis128_aesni_decrypt(struct aead_request *req) 223 { 224 static const struct aegis_block zeros = {}; 225 226 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 227 struct aegis_block tag; 228 unsigned int authsize = crypto_aead_authsize(tfm); 229 unsigned int cryptlen = req->cryptlen - authsize; 230 int err; 231 232 scatterwalk_map_and_copy(tag.bytes, req->src, 233 req->assoclen + cryptlen, authsize, 0); 234 235 err = crypto_aegis128_aesni_crypt(req, &tag, cryptlen, false); 236 if (err) 237 return err; 238 239 return crypto_memneq(tag.bytes, zeros.bytes, authsize) ? -EBADMSG : 0; 240 } 241 242 static struct aead_alg crypto_aegis128_aesni_alg = { 243 .setkey = crypto_aegis128_aesni_setkey, 244 .setauthsize = crypto_aegis128_aesni_setauthsize, 245 .encrypt = crypto_aegis128_aesni_encrypt, 246 .decrypt = crypto_aegis128_aesni_decrypt, 247 248 .ivsize = AEGIS128_NONCE_SIZE, 249 .maxauthsize = AEGIS128_MAX_AUTH_SIZE, 250 .chunksize = AEGIS128_BLOCK_SIZE, 251 252 .base = { 253 .cra_blocksize = 1, 254 .cra_ctxsize = sizeof(struct aegis_ctx) + 255 __alignof__(struct aegis_ctx), 256 .cra_priority = 400, 257 258 .cra_name = "aegis128", 259 .cra_driver_name = "aegis128-aesni", 260 261 .cra_module = THIS_MODULE, 262 } 263 }; 264 265 static int __init crypto_aegis128_aesni_module_init(void) 266 { 267 if (!boot_cpu_has(X86_FEATURE_XMM4_1) || 268 !boot_cpu_has(X86_FEATURE_AES) || 269 !cpu_has_xfeatures(XFEATURE_MASK_SSE, NULL)) 270 return -ENODEV; 271 272 return crypto_register_aead(&crypto_aegis128_aesni_alg); 273 } 274 275 static void __exit crypto_aegis128_aesni_module_exit(void) 276 { 277 crypto_unregister_aead(&crypto_aegis128_aesni_alg); 278 } 279 280 module_init(crypto_aegis128_aesni_module_init); 281 module_exit(crypto_aegis128_aesni_module_exit); 282 283 MODULE_LICENSE("GPL"); 284 MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>"); 285 MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm -- AESNI+SSE4.1 implementation"); 286 MODULE_ALIAS_CRYPTO("aegis128"); 287 MODULE_ALIAS_CRYPTO("aegis128-aesni"); 288