crypto: aegis - Add generic AEGIS AEAD implementations
This patch adds the generic implementation of the AEGIS family of AEAD
algorithms (AEGIS-128, AEGIS-128L, and AEGIS-256). The original
authors of AEGIS are Hongjun Wu and Bart Preneel.
At the time of writing, AEGIS is one of the finalists in CAESAR, an
open competition intended to select a portfolio of alternatives to
the problematic AES-GCM:
https://competitions.cr.yp.to/caesar-submissions.html
https://competitions.cr.yp.to/round3/aegisv11.pdf
Signed-off-by: Ondrej Mosnacek <omosnacek@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/aegis128.c b/crypto/aegis128.c
new file mode 100644
index 0000000..3827130
--- /dev/null
+++ b/crypto/aegis128.c
@@ -0,0 +1,463 @@
+/*
+ * 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;
+ u8 *src, *dst;
+ unsigned int chunksize;
+
+ ops->skcipher_walk_init(&walk, req, false);
+
+ while (walk.nbytes) {
+ src = walk.src.virt.addr;
+ dst = walk.dst.virt.addr;
+ chunksize = walk.nbytes;
+
+ ops->crypt_chunk(state, dst, src, chunksize);
+
+ skcipher_walk_done(&walk, 0);
+ }
+}
+
+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_flags = CRYPTO_ALG_TYPE_AEAD,
+ .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");