From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ardb@kernel.org>
Date: Fri, 8 Nov 2019 13:22:30 +0100
Subject: [PATCH] crypto: blake2s - implement generic shash driver

commit 7f9b0880925f1f9d7d59504ea0892d2ae9cfc233 upstream.

Wire up our newly added Blake2s implementation via the shash API.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 crypto/Kconfig                    |  18 ++++
 crypto/Makefile                   |   1 +
 crypto/blake2s_generic.c          | 171 ++++++++++++++++++++++++++++++
 include/crypto/internal/blake2s.h |   5 +
 4 files changed, 195 insertions(+)
 create mode 100644 crypto/blake2s_generic.c

--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -639,6 +639,24 @@ config CRYPTO_XXHASH
 	  xxHash non-cryptographic hash algorithm. Extremely fast, working at
 	  speeds close to RAM limits.
 
+config CRYPTO_BLAKE2S
+	tristate "BLAKE2s digest algorithm"
+	select CRYPTO_LIB_BLAKE2S_GENERIC
+	select CRYPTO_HASH
+	help
+	  Implementation of cryptographic hash function BLAKE2s
+	  optimized for 8-32bit platforms and can produce digests of any size
+	  between 1 to 32.  The keyed hash is also implemented.
+
+	  This module provides the following algorithms:
+
+	  - blake2s-128
+	  - blake2s-160
+	  - blake2s-224
+	  - blake2s-256
+
+	  See https://blake2.net for further information.
+
 config CRYPTO_CRCT10DIF
 	tristate "CRCT10DIF algorithm"
 	select CRYPTO_HASH
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -74,6 +74,7 @@ obj-$(CONFIG_CRYPTO_STREEBOG) += streebo
 obj-$(CONFIG_CRYPTO_WP512) += wp512.o
 CFLAGS_wp512.o := $(call cc-option,-fno-schedule-insns)  # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79149
 obj-$(CONFIG_CRYPTO_TGR192) += tgr192.o
+obj-$(CONFIG_CRYPTO_BLAKE2S) += blake2s_generic.o
 obj-$(CONFIG_CRYPTO_GF128MUL) += gf128mul.o
 obj-$(CONFIG_CRYPTO_ECB) += ecb.o
 obj-$(CONFIG_CRYPTO_CBC) += cbc.o
--- /dev/null
+++ b/crypto/blake2s_generic.c
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#include <crypto/internal/blake2s.h>
+#include <crypto/internal/simd.h>
+#include <crypto/internal/hash.h>
+
+#include <linux/types.h>
+#include <linux/jump_label.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+static int crypto_blake2s_setkey(struct crypto_shash *tfm, const u8 *key,
+				 unsigned int keylen)
+{
+	struct blake2s_tfm_ctx *tctx = crypto_shash_ctx(tfm);
+
+	if (keylen == 0 || keylen > BLAKE2S_KEY_SIZE) {
+		crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+
+	memcpy(tctx->key, key, keylen);
+	tctx->keylen = keylen;
+
+	return 0;
+}
+
+static int crypto_blake2s_init(struct shash_desc *desc)
+{
+	struct blake2s_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
+	struct blake2s_state *state = shash_desc_ctx(desc);
+	const int outlen = crypto_shash_digestsize(desc->tfm);
+
+	if (tctx->keylen)
+		blake2s_init_key(state, outlen, tctx->key, tctx->keylen);
+	else
+		blake2s_init(state, outlen);
+
+	return 0;
+}
+
+static int crypto_blake2s_update(struct shash_desc *desc, const u8 *in,
+				 unsigned int inlen)
+{
+	struct blake2s_state *state = shash_desc_ctx(desc);
+	const size_t fill = BLAKE2S_BLOCK_SIZE - state->buflen;
+
+	if (unlikely(!inlen))
+		return 0;
+	if (inlen > fill) {
+		memcpy(state->buf + state->buflen, in, fill);
+		blake2s_compress_generic(state, state->buf, 1, BLAKE2S_BLOCK_SIZE);
+		state->buflen = 0;
+		in += fill;
+		inlen -= fill;
+	}
+	if (inlen > BLAKE2S_BLOCK_SIZE) {
+		const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2S_BLOCK_SIZE);
+		/* Hash one less (full) block than strictly possible */
+		blake2s_compress_generic(state, in, nblocks - 1, BLAKE2S_BLOCK_SIZE);
+		in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
+		inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
+	}
+	memcpy(state->buf + state->buflen, in, inlen);
+	state->buflen += inlen;
+
+	return 0;
+}
+
+static int crypto_blake2s_final(struct shash_desc *desc, u8 *out)
+{
+	struct blake2s_state *state = shash_desc_ctx(desc);
+
+	blake2s_set_lastblock(state);
+	memset(state->buf + state->buflen, 0,
+	       BLAKE2S_BLOCK_SIZE - state->buflen); /* Padding */
+	blake2s_compress_generic(state, state->buf, 1, state->buflen);
+	cpu_to_le32_array(state->h, ARRAY_SIZE(state->h));
+	memcpy(out, state->h, state->outlen);
+	memzero_explicit(state, sizeof(*state));
+
+	return 0;
+}
+
+static struct shash_alg blake2s_algs[] = {{
+	.base.cra_name		= "blake2s-128",
+	.base.cra_driver_name	= "blake2s-128-generic",
+	.base.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
+	.base.cra_ctxsize	= sizeof(struct blake2s_tfm_ctx),
+	.base.cra_priority	= 200,
+	.base.cra_blocksize     = BLAKE2S_BLOCK_SIZE,
+	.base.cra_module	= THIS_MODULE,
+
+	.digestsize		= BLAKE2S_128_HASH_SIZE,
+	.setkey			= crypto_blake2s_setkey,
+	.init			= crypto_blake2s_init,
+	.update			= crypto_blake2s_update,
+	.final			= crypto_blake2s_final,
+	.descsize		= sizeof(struct blake2s_state),
+}, {
+	.base.cra_name		= "blake2s-160",
+	.base.cra_driver_name	= "blake2s-160-generic",
+	.base.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
+	.base.cra_ctxsize	= sizeof(struct blake2s_tfm_ctx),
+	.base.cra_priority	= 200,
+	.base.cra_blocksize     = BLAKE2S_BLOCK_SIZE,
+	.base.cra_module	= THIS_MODULE,
+
+	.digestsize		= BLAKE2S_160_HASH_SIZE,
+	.setkey			= crypto_blake2s_setkey,
+	.init			= crypto_blake2s_init,
+	.update			= crypto_blake2s_update,
+	.final			= crypto_blake2s_final,
+	.descsize		= sizeof(struct blake2s_state),
+}, {
+	.base.cra_name		= "blake2s-224",
+	.base.cra_driver_name	= "blake2s-224-generic",
+	.base.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
+	.base.cra_ctxsize	= sizeof(struct blake2s_tfm_ctx),
+	.base.cra_priority	= 200,
+	.base.cra_blocksize     = BLAKE2S_BLOCK_SIZE,
+	.base.cra_module	= THIS_MODULE,
+
+	.digestsize		= BLAKE2S_224_HASH_SIZE,
+	.setkey			= crypto_blake2s_setkey,
+	.init			= crypto_blake2s_init,
+	.update			= crypto_blake2s_update,
+	.final			= crypto_blake2s_final,
+	.descsize		= sizeof(struct blake2s_state),
+}, {
+	.base.cra_name		= "blake2s-256",
+	.base.cra_driver_name	= "blake2s-256-generic",
+	.base.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
+	.base.cra_ctxsize	= sizeof(struct blake2s_tfm_ctx),
+	.base.cra_priority	= 200,
+	.base.cra_blocksize     = BLAKE2S_BLOCK_SIZE,
+	.base.cra_module	= THIS_MODULE,
+
+	.digestsize		= BLAKE2S_256_HASH_SIZE,
+	.setkey			= crypto_blake2s_setkey,
+	.init			= crypto_blake2s_init,
+	.update			= crypto_blake2s_update,
+	.final			= crypto_blake2s_final,
+	.descsize		= sizeof(struct blake2s_state),
+}};
+
+static int __init blake2s_mod_init(void)
+{
+	return crypto_register_shashes(blake2s_algs, ARRAY_SIZE(blake2s_algs));
+}
+
+static void __exit blake2s_mod_exit(void)
+{
+	crypto_unregister_shashes(blake2s_algs, ARRAY_SIZE(blake2s_algs));
+}
+
+subsys_initcall(blake2s_mod_init);
+module_exit(blake2s_mod_exit);
+
+MODULE_ALIAS_CRYPTO("blake2s-128");
+MODULE_ALIAS_CRYPTO("blake2s-128-generic");
+MODULE_ALIAS_CRYPTO("blake2s-160");
+MODULE_ALIAS_CRYPTO("blake2s-160-generic");
+MODULE_ALIAS_CRYPTO("blake2s-224");
+MODULE_ALIAS_CRYPTO("blake2s-224-generic");
+MODULE_ALIAS_CRYPTO("blake2s-256");
+MODULE_ALIAS_CRYPTO("blake2s-256-generic");
+MODULE_LICENSE("GPL v2");
--- a/include/crypto/internal/blake2s.h
+++ b/include/crypto/internal/blake2s.h
@@ -5,6 +5,11 @@
 
 #include <crypto/blake2s.h>
 
+struct blake2s_tfm_ctx {
+	u8 key[BLAKE2S_KEY_SIZE];
+	unsigned int keylen;
+};
+
 void blake2s_compress_generic(struct blake2s_state *state,const u8 *block,
 			      size_t nblocks, const u32 inc);