// SPDX-License-Identifier: GPL-2.0-or-later /* * The AEGIS-128 Authenticated-Encryption Algorithm * * Copyright (c) 2017-2018 Ondrej Mosnacek <omosnacek@gmail.com> * Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved. */ #include <crypto/algapi.h> #include <crypto/internal/aead.h> #include <crypto/internal/simd.h> #include <crypto/internal/skcipher.h> #include <crypto/scatterwalk.h> #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/scatterlist.h> #include <asm/simd.h> #include "aegis.h" #define AEGIS128_NONCE_SIZE 16 #define AEGIS128_STATE_BLOCKS 5 #define AEGIS128_KEY_SIZE 16 #define AEGIS128_MIN_AUTH_SIZE 8 #define AEGIS128_MAX_AUTH_SIZE 16 struct aegis_state { union aegis_block blocks[AEGIS128_STATE_BLOCKS]; }; struct aegis_ctx { union aegis_block key; }; struct aegis128_ops { int (*skcipher_walk_init)(struct skcipher_walk *walk, struct aead_request *req, bool atomic); void (*crypt_chunk)(struct aegis_state *state, u8 *dst, const u8 *src, unsigned int size); }; static bool have_simd; static const union aegis_block crypto_aegis_const[2] = { { .words64 = { cpu_to_le64(U64_C(0x0d08050302010100)), cpu_to_le64(U64_C(0x6279e99059372215)), } }, { .words64 = { cpu_to_le64(U64_C(0xf12fc26d55183ddb)), cpu_to_le64(U64_C(0xdd28b57342311120)), } }, }; static bool aegis128_do_simd(void) { #ifdef CONFIG_CRYPTO_AEGIS128_SIMD if (have_simd) return crypto_simd_usable(); #endif return false; } bool crypto_aegis128_have_simd(void); void crypto_aegis128_update_simd(struct aegis_state *state, const void *msg); void crypto_aegis128_encrypt_chunk_simd(struct aegis_state *state, u8 *dst, const u8 *src, unsigned int size); void crypto_aegis128_decrypt_chunk_simd(struct aegis_state *state, u8 *dst, const u8 *src, unsigned int size); static void crypto_aegis128_update(struct aegis_state *state) { union aegis_block tmp; unsigned int i; tmp = state->blocks[AEGIS128_STATE_BLOCKS - 1]; for (i = AEGIS128_STATE_BLOCKS - 1; i > 0; i--) crypto_aegis_aesenc(&state->blocks[i], &state->blocks[i - 1], &state->blocks[i]); crypto_aegis_aesenc(&state->blocks[0], &tmp, &state->blocks[0]); } static void crypto_aegis128_update_a(struct aegis_state *state, const union aegis_block *msg) { if (aegis128_do_simd()) { crypto_aegis128_update_simd(state, msg); return; } crypto_aegis128_update(state); crypto_aegis_block_xor(&state->blocks[0], msg); } static void crypto_aegis128_update_u(struct aegis_state *state, const void *msg) { if (aegis128_do_simd()) { crypto_aegis128_update_simd(state, msg); return; } crypto_aegis128_update(state); crypto_xor(state->blocks[0].bytes, msg, AEGIS_BLOCK_SIZE); } static void crypto_aegis128_init(struct aegis_state *state, const union aegis_block *key, const u8 *iv) { union aegis_block key_iv; unsigned int i; key_iv = *key; crypto_xor(key_iv.bytes, iv, AEGIS_BLOCK_SIZE); state->blocks[0] = key_iv; state->blocks[1] = crypto_aegis_const[1]; state->blocks[2] = crypto_aegis_const[0]; state->blocks[3] = *key; state->blocks[4] = *key; crypto_aegis_block_xor(&state->blocks[3], &crypto_aegis_const[0]); crypto_aegis_block_xor(&state->blocks[4], &crypto_aegis_const[1]); for (i = 0; i < 5; i++) { crypto_aegis128_update_a(state, key); crypto_aegis128_update_a(state, &key_iv); } } static void crypto_aegis128_ad(struct aegis_state *state, const u8 *src, unsigned int size) { if (AEGIS_ALIGNED(src)) { const union aegis_block *src_blk = (const union aegis_block *)src; while (size >= AEGIS_BLOCK_SIZE) { crypto_aegis128_update_a(state, src_blk); size -= AEGIS_BLOCK_SIZE; src_blk++; } } else { while (size >= AEGIS_BLOCK_SIZE) { crypto_aegis128_update_u(state, src); size -= AEGIS_BLOCK_SIZE; src += AEGIS_BLOCK_SIZE; } } } static void crypto_aegis128_encrypt_chunk(struct aegis_state *state, u8 *dst, const u8 *src, unsigned int size) { union aegis_block tmp; if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) { while (size >= AEGIS_BLOCK_SIZE) { union aegis_block *dst_blk = (union aegis_block *)dst; const union aegis_block *src_blk = (const union aegis_block *)src; tmp = state->blocks[2]; crypto_aegis_block_and(&tmp, &state->blocks[3]); crypto_aegis_block_xor(&tmp, &state->blocks[4]); crypto_aegis_block_xor(&tmp, &state->blocks[1]); crypto_aegis_block_xor(&tmp, src_blk); crypto_aegis128_update_a(state, src_blk); *dst_blk = tmp; size -= AEGIS_BLOCK_SIZE; src += AEGIS_BLOCK_SIZE; dst += AEGIS_BLOCK_SIZE; } } else { while (size >= AEGIS_BLOCK_SIZE) { tmp = state->blocks[2]; crypto_aegis_block_and(&tmp, &state->blocks[3]); crypto_aegis_block_xor(&tmp, &state->blocks[4]); crypto_aegis_block_xor(&tmp, &state->blocks[1]); crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE); crypto_aegis128_update_u(state, src); memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE); size -= AEGIS_BLOCK_SIZE; src += AEGIS_BLOCK_SIZE; dst += AEGIS_BLOCK_SIZE; } } if (size > 0) { union aegis_block msg = {}; memcpy(msg.bytes, src, size); tmp = state->blocks[2]; crypto_aegis_block_and(&tmp, &state->blocks[3]); crypto_aegis_block_xor(&tmp, &state->blocks[4]); crypto_aegis_block_xor(&tmp, &state->blocks[1]); crypto_aegis128_update_a(state, &msg); crypto_aegis_block_xor(&msg, &tmp); memcpy(dst, msg.bytes, size); } } static void crypto_aegis128_decrypt_chunk(struct aegis_state *state, u8 *dst, const u8 *src, unsigned int size) { union aegis_block tmp; if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) { while (size >= AEGIS_BLOCK_SIZE) { union aegis_block *dst_blk = (union aegis_block *)dst; const union aegis_block *src_blk = (const union aegis_block *)src; tmp = state->blocks[2]; crypto_aegis_block_and(&tmp, &state->blocks[3]); crypto_aegis_block_xor(&tmp, &state->blocks[4]); crypto_aegis_block_xor(&tmp, &state->blocks[1]); crypto_aegis_block_xor(&tmp, src_blk); crypto_aegis128_update_a(state, &tmp); *dst_blk = tmp; size -= AEGIS_BLOCK_SIZE; src += AEGIS_BLOCK_SIZE; dst += AEGIS_BLOCK_SIZE; } } else { while (size >= AEGIS_BLOCK_SIZE) { tmp = state->blocks[2]; crypto_aegis_block_and(&tmp, &state->blocks[3]); crypto_aegis_block_xor(&tmp, &state->blocks[4]); crypto_aegis_block_xor(&tmp, &state->blocks[1]); crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE); crypto_aegis128_update_a(state, &tmp); memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE); size -= AEGIS_BLOCK_SIZE; src += AEGIS_BLOCK_SIZE; dst += AEGIS_BLOCK_SIZE; } } if (size > 0) { union aegis_block msg = {}; memcpy(msg.bytes, src, size); tmp = state->blocks[2]; crypto_aegis_block_and(&tmp, &state->blocks[3]); crypto_aegis_block_xor(&tmp, &state->blocks[4]); crypto_aegis_block_xor(&tmp, &state->blocks[1]); crypto_aegis_block_xor(&msg, &tmp); memset(msg.bytes + size, 0, AEGIS_BLOCK_SIZE - size); crypto_aegis128_update_a(state, &msg); memcpy(dst, msg.bytes, size); } } static void crypto_aegis128_process_ad(struct aegis_state *state, struct scatterlist *sg_src, unsigned int assoclen) { struct scatter_walk walk; union aegis_block buf; unsigned int pos = 0; scatterwalk_start(&walk, sg_src); while (assoclen != 0) { unsigned int size = scatterwalk_clamp(&walk, assoclen); unsigned int left = size; void *mapped = scatterwalk_map(&walk); const u8 *src = (const u8 *)mapped; if (pos + size >= AEGIS_BLOCK_SIZE) { if (pos > 0) { unsigned int fill = AEGIS_BLOCK_SIZE - pos; memcpy(buf.bytes + pos, src, fill); crypto_aegis128_update_a(state, &buf); pos = 0; left -= fill; src += fill; } crypto_aegis128_ad(state, src, left); src += left & ~(AEGIS_BLOCK_SIZE - 1); left &= AEGIS_BLOCK_SIZE - 1; } memcpy(buf.bytes + pos, src, left); pos += left; assoclen -= size; scatterwalk_unmap(mapped); scatterwalk_advance(&walk, size); scatterwalk_done(&walk, 0, assoclen); } if (pos > 0) { memset(buf.bytes + pos, 0, AEGIS_BLOCK_SIZE - pos); crypto_aegis128_update_a(state, &buf); } } static void crypto_aegis128_process_crypt(struct aegis_state *state, struct aead_request *req, const struct aegis128_ops *ops) { struct skcipher_walk walk; ops->skcipher_walk_init(&walk, req, false); while (walk.nbytes) { unsigned int nbytes = walk.nbytes; if (nbytes < walk.total) nbytes = round_down(nbytes, walk.stride); ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr, nbytes); skcipher_walk_done(&walk, walk.nbytes - nbytes); } } static void crypto_aegis128_final(struct aegis_state *state, union aegis_block *tag_xor, u64 assoclen, u64 cryptlen) { u64 assocbits = assoclen * 8; u64 cryptbits = cryptlen * 8; union aegis_block tmp; unsigned int i; tmp.words64[0] = cpu_to_le64(assocbits); tmp.words64[1] = cpu_to_le64(cryptbits); crypto_aegis_block_xor(&tmp, &state->blocks[3]); for (i = 0; i < 7; i++) crypto_aegis128_update_a(state, &tmp); for (i = 0; i < AEGIS128_STATE_BLOCKS; i++) crypto_aegis_block_xor(tag_xor, &state->blocks[i]); } static int crypto_aegis128_setkey(struct crypto_aead *aead, const u8 *key, unsigned int keylen) { struct aegis_ctx *ctx = crypto_aead_ctx(aead); if (keylen != AEGIS128_KEY_SIZE) { crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN); return -EINVAL; } memcpy(ctx->key.bytes, key, AEGIS128_KEY_SIZE); return 0; } static int crypto_aegis128_setauthsize(struct crypto_aead *tfm, unsigned int authsize) { if (authsize > AEGIS128_MAX_AUTH_SIZE) return -EINVAL; if (authsize < AEGIS128_MIN_AUTH_SIZE) return -EINVAL; return 0; } static void crypto_aegis128_crypt(struct aead_request *req, union aegis_block *tag_xor, unsigned int cryptlen, const struct aegis128_ops *ops) { struct crypto_aead *tfm = crypto_aead_reqtfm(req); struct aegis_ctx *ctx = crypto_aead_ctx(tfm); struct aegis_state state; crypto_aegis128_init(&state, &ctx->key, req->iv); crypto_aegis128_process_ad(&state, req->src, req->assoclen); crypto_aegis128_process_crypt(&state, req, ops); crypto_aegis128_final(&state, tag_xor, req->assoclen, cryptlen); } static int crypto_aegis128_encrypt(struct aead_request *req) { const struct aegis128_ops *ops = &(struct aegis128_ops){ .skcipher_walk_init = skcipher_walk_aead_encrypt, .crypt_chunk = crypto_aegis128_encrypt_chunk, }; struct crypto_aead *tfm = crypto_aead_reqtfm(req); union aegis_block tag = {}; unsigned int authsize = crypto_aead_authsize(tfm); unsigned int cryptlen = req->cryptlen; if (aegis128_do_simd()) ops = &(struct aegis128_ops){ .skcipher_walk_init = skcipher_walk_aead_encrypt, .crypt_chunk = crypto_aegis128_encrypt_chunk_simd }; crypto_aegis128_crypt(req, &tag, cryptlen, ops); scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen, authsize, 1); return 0; } static int crypto_aegis128_decrypt(struct aead_request *req) { const struct aegis128_ops *ops = &(struct aegis128_ops){ .skcipher_walk_init = skcipher_walk_aead_decrypt, .crypt_chunk = crypto_aegis128_decrypt_chunk, }; static const u8 zeros[AEGIS128_MAX_AUTH_SIZE] = {}; struct crypto_aead *tfm = crypto_aead_reqtfm(req); union aegis_block tag; unsigned int authsize = crypto_aead_authsize(tfm); unsigned int cryptlen = req->cryptlen - authsize; scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen, authsize, 0); if (aegis128_do_simd()) ops = &(struct aegis128_ops){ .skcipher_walk_init = skcipher_walk_aead_decrypt, .crypt_chunk = crypto_aegis128_decrypt_chunk_simd }; crypto_aegis128_crypt(req, &tag, cryptlen, ops); return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0; } static struct aead_alg crypto_aegis128_alg = { .setkey = crypto_aegis128_setkey, .setauthsize = crypto_aegis128_setauthsize, .encrypt = crypto_aegis128_encrypt, .decrypt = crypto_aegis128_decrypt, .ivsize = AEGIS128_NONCE_SIZE, .maxauthsize = AEGIS128_MAX_AUTH_SIZE, .chunksize = AEGIS_BLOCK_SIZE, .base = { .cra_blocksize = 1, .cra_ctxsize = sizeof(struct aegis_ctx), .cra_alignmask = 0, .cra_priority = 100, .cra_name = "aegis128", .cra_driver_name = "aegis128-generic", .cra_module = THIS_MODULE, } }; static int __init crypto_aegis128_module_init(void) { if (IS_ENABLED(CONFIG_CRYPTO_AEGIS128_SIMD)) have_simd = crypto_aegis128_have_simd(); return crypto_register_aead(&crypto_aegis128_alg); } static void __exit crypto_aegis128_module_exit(void) { crypto_unregister_aead(&crypto_aegis128_alg); } subsys_initcall(crypto_aegis128_module_init); module_exit(crypto_aegis128_module_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>"); MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm"); MODULE_ALIAS_CRYPTO("aegis128"); MODULE_ALIAS_CRYPTO("aegis128-generic");