linux/arch/x86/crypto/aegis128-aesni-glue.c
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   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
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