| /* |
| * 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. |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License as published by the Free |
| * Software Foundation; either version 2 of the License, or (at your option) |
| * any later version. |
| */ |
| |
| #include <crypto/algapi.h> |
| #include <crypto/internal/aead.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 "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 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) |
| { |
| 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) |
| { |
| 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) |
| { |
| static const struct aegis128_ops 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; |
| |
| 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) |
| { |
| static const struct aegis128_ops 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); |
| |
| crypto_aegis128_crypt(req, &tag, cryptlen, &ops); |
| |
| return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0; |
| } |
| |
| static int crypto_aegis128_init_tfm(struct crypto_aead *tfm) |
| { |
| return 0; |
| } |
| |
| static void crypto_aegis128_exit_tfm(struct crypto_aead *tfm) |
| { |
| } |
| |
| static struct aead_alg crypto_aegis128_alg = { |
| .setkey = crypto_aegis128_setkey, |
| .setauthsize = crypto_aegis128_setauthsize, |
| .encrypt = crypto_aegis128_encrypt, |
| .decrypt = crypto_aegis128_decrypt, |
| .init = crypto_aegis128_init_tfm, |
| .exit = crypto_aegis128_exit_tfm, |
| |
| .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) |
| { |
| return crypto_register_aead(&crypto_aegis128_alg); |
| } |
| |
| static void __exit crypto_aegis128_module_exit(void) |
| { |
| crypto_unregister_aead(&crypto_aegis128_alg); |
| } |
| |
| module_init(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"); |