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-rw-r--r--target/linux/generic/backport-5.4/080-wireguard-0002-crypto-chacha-move-existing-library-code-into-lib-cr.patch668
1 files changed, 668 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0002-crypto-chacha-move-existing-library-code-into-lib-cr.patch b/target/linux/generic/backport-5.4/080-wireguard-0002-crypto-chacha-move-existing-library-code-into-lib-cr.patch
new file mode 100644
index 0000000000..177b5840d5
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0002-crypto-chacha-move-existing-library-code-into-lib-cr.patch
@@ -0,0 +1,668 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Ard Biesheuvel <ardb@kernel.org>
+Date: Fri, 8 Nov 2019 13:22:08 +0100
+Subject: [PATCH] crypto: chacha - move existing library code into lib/crypto
+
+commit 5fb8ef25803ef33e2eb60b626435828b937bed75 upstream.
+
+Currently, our generic ChaCha implementation consists of a permute
+function in lib/chacha.c that operates on the 64-byte ChaCha state
+directly [and which is always included into the core kernel since it
+is used by the /dev/random driver], and the crypto API plumbing to
+expose it as a skcipher.
+
+In order to support in-kernel users that need the ChaCha streamcipher
+but have no need [or tolerance] for going through the abstractions of
+the crypto API, let's expose the streamcipher bits via a library API
+as well, in a way that permits the implementation to be superseded by
+an architecture specific one if provided.
+
+So move the streamcipher code into a separate module in lib/crypto,
+and expose the init() and crypt() routines to users of the library.
+
+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>
+---
+ arch/arm/crypto/chacha-neon-glue.c | 2 +-
+ arch/arm64/crypto/chacha-neon-glue.c | 2 +-
+ arch/x86/crypto/chacha_glue.c | 2 +-
+ crypto/Kconfig | 1 +
+ crypto/chacha_generic.c | 60 ++--------------------
+ include/crypto/chacha.h | 77 ++++++++++++++++++++++------
+ include/crypto/internal/chacha.h | 53 +++++++++++++++++++
+ lib/Makefile | 3 +-
+ lib/crypto/Kconfig | 26 ++++++++++
+ lib/crypto/Makefile | 4 ++
+ lib/{ => crypto}/chacha.c | 20 ++++----
+ lib/crypto/libchacha.c | 35 +++++++++++++
+ 12 files changed, 199 insertions(+), 86 deletions(-)
+ create mode 100644 include/crypto/internal/chacha.h
+ rename lib/{ => crypto}/chacha.c (88%)
+ create mode 100644 lib/crypto/libchacha.c
+
+--- a/arch/arm/crypto/chacha-neon-glue.c
++++ b/arch/arm/crypto/chacha-neon-glue.c
+@@ -20,7 +20,7 @@
+ */
+
+ #include <crypto/algapi.h>
+-#include <crypto/chacha.h>
++#include <crypto/internal/chacha.h>
+ #include <crypto/internal/simd.h>
+ #include <crypto/internal/skcipher.h>
+ #include <linux/kernel.h>
+--- a/arch/arm64/crypto/chacha-neon-glue.c
++++ b/arch/arm64/crypto/chacha-neon-glue.c
+@@ -20,7 +20,7 @@
+ */
+
+ #include <crypto/algapi.h>
+-#include <crypto/chacha.h>
++#include <crypto/internal/chacha.h>
+ #include <crypto/internal/simd.h>
+ #include <crypto/internal/skcipher.h>
+ #include <linux/kernel.h>
+--- a/arch/x86/crypto/chacha_glue.c
++++ b/arch/x86/crypto/chacha_glue.c
+@@ -7,7 +7,7 @@
+ */
+
+ #include <crypto/algapi.h>
+-#include <crypto/chacha.h>
++#include <crypto/internal/chacha.h>
+ #include <crypto/internal/simd.h>
+ #include <crypto/internal/skcipher.h>
+ #include <linux/kernel.h>
+--- a/crypto/Kconfig
++++ b/crypto/Kconfig
+@@ -1393,6 +1393,7 @@ config CRYPTO_SALSA20
+
+ config CRYPTO_CHACHA20
+ tristate "ChaCha stream cipher algorithms"
++ select CRYPTO_LIB_CHACHA_GENERIC
+ select CRYPTO_BLKCIPHER
+ help
+ The ChaCha20, XChaCha20, and XChaCha12 stream cipher algorithms.
+--- a/crypto/chacha_generic.c
++++ b/crypto/chacha_generic.c
+@@ -8,29 +8,10 @@
+
+ #include <asm/unaligned.h>
+ #include <crypto/algapi.h>
+-#include <crypto/chacha.h>
++#include <crypto/internal/chacha.h>
+ #include <crypto/internal/skcipher.h>
+ #include <linux/module.h>
+
+-static void chacha_docrypt(u32 *state, u8 *dst, const u8 *src,
+- unsigned int bytes, int nrounds)
+-{
+- /* aligned to potentially speed up crypto_xor() */
+- u8 stream[CHACHA_BLOCK_SIZE] __aligned(sizeof(long));
+-
+- while (bytes >= CHACHA_BLOCK_SIZE) {
+- chacha_block(state, stream, nrounds);
+- crypto_xor_cpy(dst, src, stream, CHACHA_BLOCK_SIZE);
+- bytes -= CHACHA_BLOCK_SIZE;
+- dst += CHACHA_BLOCK_SIZE;
+- src += CHACHA_BLOCK_SIZE;
+- }
+- if (bytes) {
+- chacha_block(state, stream, nrounds);
+- crypto_xor_cpy(dst, src, stream, bytes);
+- }
+-}
+-
+ static int chacha_stream_xor(struct skcipher_request *req,
+ const struct chacha_ctx *ctx, const u8 *iv)
+ {
+@@ -48,8 +29,8 @@ static int chacha_stream_xor(struct skci
+ if (nbytes < walk.total)
+ nbytes = round_down(nbytes, CHACHA_BLOCK_SIZE);
+
+- chacha_docrypt(state, walk.dst.virt.addr, walk.src.virt.addr,
+- nbytes, ctx->nrounds);
++ chacha_crypt_generic(state, walk.dst.virt.addr,
++ walk.src.virt.addr, nbytes, ctx->nrounds);
+ err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
+ }
+
+@@ -58,41 +39,10 @@ static int chacha_stream_xor(struct skci
+
+ void crypto_chacha_init(u32 *state, const struct chacha_ctx *ctx, const u8 *iv)
+ {
+- state[0] = 0x61707865; /* "expa" */
+- state[1] = 0x3320646e; /* "nd 3" */
+- state[2] = 0x79622d32; /* "2-by" */
+- state[3] = 0x6b206574; /* "te k" */
+- state[4] = ctx->key[0];
+- state[5] = ctx->key[1];
+- state[6] = ctx->key[2];
+- state[7] = ctx->key[3];
+- state[8] = ctx->key[4];
+- state[9] = ctx->key[5];
+- state[10] = ctx->key[6];
+- state[11] = ctx->key[7];
+- state[12] = get_unaligned_le32(iv + 0);
+- state[13] = get_unaligned_le32(iv + 4);
+- state[14] = get_unaligned_le32(iv + 8);
+- state[15] = get_unaligned_le32(iv + 12);
++ chacha_init_generic(state, ctx->key, iv);
+ }
+ EXPORT_SYMBOL_GPL(crypto_chacha_init);
+
+-static int chacha_setkey(struct crypto_skcipher *tfm, const u8 *key,
+- unsigned int keysize, int nrounds)
+-{
+- struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+- int i;
+-
+- if (keysize != CHACHA_KEY_SIZE)
+- return -EINVAL;
+-
+- for (i = 0; i < ARRAY_SIZE(ctx->key); i++)
+- ctx->key[i] = get_unaligned_le32(key + i * sizeof(u32));
+-
+- ctx->nrounds = nrounds;
+- return 0;
+-}
+-
+ int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
+ unsigned int keysize)
+ {
+@@ -126,7 +76,7 @@ int crypto_xchacha_crypt(struct skcipher
+
+ /* Compute the subkey given the original key and first 128 nonce bits */
+ crypto_chacha_init(state, ctx, req->iv);
+- hchacha_block(state, subctx.key, ctx->nrounds);
++ hchacha_block_generic(state, subctx.key, ctx->nrounds);
+ subctx.nrounds = ctx->nrounds;
+
+ /* Build the real IV */
+--- a/include/crypto/chacha.h
++++ b/include/crypto/chacha.h
+@@ -15,9 +15,8 @@
+ #ifndef _CRYPTO_CHACHA_H
+ #define _CRYPTO_CHACHA_H
+
+-#include <crypto/skcipher.h>
++#include <asm/unaligned.h>
+ #include <linux/types.h>
+-#include <linux/crypto.h>
+
+ /* 32-bit stream position, then 96-bit nonce (RFC7539 convention) */
+ #define CHACHA_IV_SIZE 16
+@@ -29,26 +28,70 @@
+ /* 192-bit nonce, then 64-bit stream position */
+ #define XCHACHA_IV_SIZE 32
+
+-struct chacha_ctx {
+- u32 key[8];
+- int nrounds;
+-};
+-
+-void chacha_block(u32 *state, u8 *stream, int nrounds);
++void chacha_block_generic(u32 *state, u8 *stream, int nrounds);
+ static inline void chacha20_block(u32 *state, u8 *stream)
+ {
+- chacha_block(state, stream, 20);
++ chacha_block_generic(state, stream, 20);
+ }
+-void hchacha_block(const u32 *in, u32 *out, int nrounds);
+
+-void crypto_chacha_init(u32 *state, const struct chacha_ctx *ctx, const u8 *iv);
++void hchacha_block_arch(const u32 *state, u32 *out, int nrounds);
++void hchacha_block_generic(const u32 *state, u32 *out, int nrounds);
++
++static inline void hchacha_block(const u32 *state, u32 *out, int nrounds)
++{
++ if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CHACHA))
++ hchacha_block_arch(state, out, nrounds);
++ else
++ hchacha_block_generic(state, out, nrounds);
++}
+
+-int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
+- unsigned int keysize);
+-int crypto_chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
+- unsigned int keysize);
++void chacha_init_arch(u32 *state, const u32 *key, const u8 *iv);
++static inline void chacha_init_generic(u32 *state, const u32 *key, const u8 *iv)
++{
++ state[0] = 0x61707865; /* "expa" */
++ state[1] = 0x3320646e; /* "nd 3" */
++ state[2] = 0x79622d32; /* "2-by" */
++ state[3] = 0x6b206574; /* "te k" */
++ state[4] = key[0];
++ state[5] = key[1];
++ state[6] = key[2];
++ state[7] = key[3];
++ state[8] = key[4];
++ state[9] = key[5];
++ state[10] = key[6];
++ state[11] = key[7];
++ state[12] = get_unaligned_le32(iv + 0);
++ state[13] = get_unaligned_le32(iv + 4);
++ state[14] = get_unaligned_le32(iv + 8);
++ state[15] = get_unaligned_le32(iv + 12);
++}
+
+-int crypto_chacha_crypt(struct skcipher_request *req);
+-int crypto_xchacha_crypt(struct skcipher_request *req);
++static inline void chacha_init(u32 *state, const u32 *key, const u8 *iv)
++{
++ if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CHACHA))
++ chacha_init_arch(state, key, iv);
++ else
++ chacha_init_generic(state, key, iv);
++}
++
++void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src,
++ unsigned int bytes, int nrounds);
++void chacha_crypt_generic(u32 *state, u8 *dst, const u8 *src,
++ unsigned int bytes, int nrounds);
++
++static inline void chacha_crypt(u32 *state, u8 *dst, const u8 *src,
++ unsigned int bytes, int nrounds)
++{
++ if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CHACHA))
++ chacha_crypt_arch(state, dst, src, bytes, nrounds);
++ else
++ chacha_crypt_generic(state, dst, src, bytes, nrounds);
++}
++
++static inline void chacha20_crypt(u32 *state, u8 *dst, const u8 *src,
++ unsigned int bytes)
++{
++ chacha_crypt(state, dst, src, bytes, 20);
++}
+
+ #endif /* _CRYPTO_CHACHA_H */
+--- /dev/null
++++ b/include/crypto/internal/chacha.h
+@@ -0,0 +1,53 @@
++/* SPDX-License-Identifier: GPL-2.0 */
++
++#ifndef _CRYPTO_INTERNAL_CHACHA_H
++#define _CRYPTO_INTERNAL_CHACHA_H
++
++#include <crypto/chacha.h>
++#include <crypto/internal/skcipher.h>
++#include <linux/crypto.h>
++
++struct chacha_ctx {
++ u32 key[8];
++ int nrounds;
++};
++
++void crypto_chacha_init(u32 *state, const struct chacha_ctx *ctx, const u8 *iv);
++
++static inline int chacha_setkey(struct crypto_skcipher *tfm, const u8 *key,
++ unsigned int keysize, int nrounds)
++{
++ struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
++ int i;
++
++ if (keysize != CHACHA_KEY_SIZE)
++ return -EINVAL;
++
++ for (i = 0; i < ARRAY_SIZE(ctx->key); i++)
++ ctx->key[i] = get_unaligned_le32(key + i * sizeof(u32));
++
++ ctx->nrounds = nrounds;
++ return 0;
++}
++
++static inline int chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
++ unsigned int keysize)
++{
++ return chacha_setkey(tfm, key, keysize, 20);
++}
++
++static int inline chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
++ unsigned int keysize)
++{
++ return chacha_setkey(tfm, key, keysize, 12);
++}
++
++int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
++ unsigned int keysize);
++int crypto_chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
++ unsigned int keysize);
++
++int crypto_chacha_crypt(struct skcipher_request *req);
++int crypto_xchacha_crypt(struct skcipher_request *req);
++
++#endif /* _CRYPTO_CHACHA_H */
+--- a/lib/Makefile
++++ b/lib/Makefile
+@@ -26,8 +26,7 @@ endif
+
+ lib-y := ctype.o string.o vsprintf.o cmdline.o \
+ rbtree.o radix-tree.o timerqueue.o xarray.o \
+- idr.o extable.o \
+- sha1.o chacha.o irq_regs.o argv_split.o \
++ idr.o extable.o sha1.o irq_regs.o argv_split.o \
+ flex_proportions.o ratelimit.o show_mem.o \
+ is_single_threaded.o plist.o decompress.o kobject_uevent.o \
+ earlycpio.o seq_buf.o siphash.o dec_and_lock.o \
+--- a/lib/crypto/Kconfig
++++ b/lib/crypto/Kconfig
+@@ -8,6 +8,32 @@ config CRYPTO_LIB_AES
+ config CRYPTO_LIB_ARC4
+ tristate
+
++config CRYPTO_ARCH_HAVE_LIB_CHACHA
++ tristate
++ help
++ Declares whether the architecture provides an arch-specific
++ accelerated implementation of the ChaCha library interface,
++ either builtin or as a module.
++
++config CRYPTO_LIB_CHACHA_GENERIC
++ tristate
++ select CRYPTO_ALGAPI
++ help
++ This symbol can be depended upon by arch implementations of the
++ ChaCha library interface that require the generic code as a
++ fallback, e.g., for SIMD implementations. If no arch specific
++ implementation is enabled, this implementation serves the users
++ of CRYPTO_LIB_CHACHA.
++
++config CRYPTO_LIB_CHACHA
++ tristate "ChaCha library interface"
++ depends on CRYPTO_ARCH_HAVE_LIB_CHACHA || !CRYPTO_ARCH_HAVE_LIB_CHACHA
++ select CRYPTO_LIB_CHACHA_GENERIC if CRYPTO_ARCH_HAVE_LIB_CHACHA=n
++ help
++ Enable the ChaCha library interface. This interface may be fulfilled
++ by either the generic implementation or an arch-specific one, if one
++ is available and enabled.
++
+ config CRYPTO_LIB_DES
+ tristate
+
+--- a/lib/crypto/Makefile
++++ b/lib/crypto/Makefile
+@@ -1,5 +1,9 @@
+ # SPDX-License-Identifier: GPL-2.0
+
++# chacha is used by the /dev/random driver which is always builtin
++obj-y += chacha.o
++obj-$(CONFIG_CRYPTO_LIB_CHACHA_GENERIC) += libchacha.o
++
+ obj-$(CONFIG_CRYPTO_LIB_AES) += libaes.o
+ libaes-y := aes.o
+
+--- a/lib/chacha.c
++++ /dev/null
+@@ -1,113 +0,0 @@
+-// SPDX-License-Identifier: GPL-2.0-or-later
+-/*
+- * The "hash function" used as the core of the ChaCha stream cipher (RFC7539)
+- *
+- * Copyright (C) 2015 Martin Willi
+- */
+-
+-#include <linux/kernel.h>
+-#include <linux/export.h>
+-#include <linux/bitops.h>
+-#include <linux/cryptohash.h>
+-#include <asm/unaligned.h>
+-#include <crypto/chacha.h>
+-
+-static void chacha_permute(u32 *x, int nrounds)
+-{
+- int i;
+-
+- /* whitelist the allowed round counts */
+- WARN_ON_ONCE(nrounds != 20 && nrounds != 12);
+-
+- for (i = 0; i < nrounds; i += 2) {
+- x[0] += x[4]; x[12] = rol32(x[12] ^ x[0], 16);
+- x[1] += x[5]; x[13] = rol32(x[13] ^ x[1], 16);
+- x[2] += x[6]; x[14] = rol32(x[14] ^ x[2], 16);
+- x[3] += x[7]; x[15] = rol32(x[15] ^ x[3], 16);
+-
+- x[8] += x[12]; x[4] = rol32(x[4] ^ x[8], 12);
+- x[9] += x[13]; x[5] = rol32(x[5] ^ x[9], 12);
+- x[10] += x[14]; x[6] = rol32(x[6] ^ x[10], 12);
+- x[11] += x[15]; x[7] = rol32(x[7] ^ x[11], 12);
+-
+- x[0] += x[4]; x[12] = rol32(x[12] ^ x[0], 8);
+- x[1] += x[5]; x[13] = rol32(x[13] ^ x[1], 8);
+- x[2] += x[6]; x[14] = rol32(x[14] ^ x[2], 8);
+- x[3] += x[7]; x[15] = rol32(x[15] ^ x[3], 8);
+-
+- x[8] += x[12]; x[4] = rol32(x[4] ^ x[8], 7);
+- x[9] += x[13]; x[5] = rol32(x[5] ^ x[9], 7);
+- x[10] += x[14]; x[6] = rol32(x[6] ^ x[10], 7);
+- x[11] += x[15]; x[7] = rol32(x[7] ^ x[11], 7);
+-
+- x[0] += x[5]; x[15] = rol32(x[15] ^ x[0], 16);
+- x[1] += x[6]; x[12] = rol32(x[12] ^ x[1], 16);
+- x[2] += x[7]; x[13] = rol32(x[13] ^ x[2], 16);
+- x[3] += x[4]; x[14] = rol32(x[14] ^ x[3], 16);
+-
+- x[10] += x[15]; x[5] = rol32(x[5] ^ x[10], 12);
+- x[11] += x[12]; x[6] = rol32(x[6] ^ x[11], 12);
+- x[8] += x[13]; x[7] = rol32(x[7] ^ x[8], 12);
+- x[9] += x[14]; x[4] = rol32(x[4] ^ x[9], 12);
+-
+- x[0] += x[5]; x[15] = rol32(x[15] ^ x[0], 8);
+- x[1] += x[6]; x[12] = rol32(x[12] ^ x[1], 8);
+- x[2] += x[7]; x[13] = rol32(x[13] ^ x[2], 8);
+- x[3] += x[4]; x[14] = rol32(x[14] ^ x[3], 8);
+-
+- x[10] += x[15]; x[5] = rol32(x[5] ^ x[10], 7);
+- x[11] += x[12]; x[6] = rol32(x[6] ^ x[11], 7);
+- x[8] += x[13]; x[7] = rol32(x[7] ^ x[8], 7);
+- x[9] += x[14]; x[4] = rol32(x[4] ^ x[9], 7);
+- }
+-}
+-
+-/**
+- * chacha_block - generate one keystream block and increment block counter
+- * @state: input state matrix (16 32-bit words)
+- * @stream: output keystream block (64 bytes)
+- * @nrounds: number of rounds (20 or 12; 20 is recommended)
+- *
+- * This is the ChaCha core, a function from 64-byte strings to 64-byte strings.
+- * The caller has already converted the endianness of the input. This function
+- * also handles incrementing the block counter in the input matrix.
+- */
+-void chacha_block(u32 *state, u8 *stream, int nrounds)
+-{
+- u32 x[16];
+- int i;
+-
+- memcpy(x, state, 64);
+-
+- chacha_permute(x, nrounds);
+-
+- for (i = 0; i < ARRAY_SIZE(x); i++)
+- put_unaligned_le32(x[i] + state[i], &stream[i * sizeof(u32)]);
+-
+- state[12]++;
+-}
+-EXPORT_SYMBOL(chacha_block);
+-
+-/**
+- * hchacha_block - abbreviated ChaCha core, for XChaCha
+- * @in: input state matrix (16 32-bit words)
+- * @out: output (8 32-bit words)
+- * @nrounds: number of rounds (20 or 12; 20 is recommended)
+- *
+- * HChaCha is the ChaCha equivalent of HSalsa and is an intermediate step
+- * towards XChaCha (see https://cr.yp.to/snuffle/xsalsa-20081128.pdf). HChaCha
+- * skips the final addition of the initial state, and outputs only certain words
+- * of the state. It should not be used for streaming directly.
+- */
+-void hchacha_block(const u32 *in, u32 *out, int nrounds)
+-{
+- u32 x[16];
+-
+- memcpy(x, in, 64);
+-
+- chacha_permute(x, nrounds);
+-
+- memcpy(&out[0], &x[0], 16);
+- memcpy(&out[4], &x[12], 16);
+-}
+-EXPORT_SYMBOL(hchacha_block);
+--- /dev/null
++++ b/lib/crypto/chacha.c
+@@ -0,0 +1,115 @@
++// SPDX-License-Identifier: GPL-2.0-or-later
++/*
++ * The "hash function" used as the core of the ChaCha stream cipher (RFC7539)
++ *
++ * Copyright (C) 2015 Martin Willi
++ */
++
++#include <linux/bug.h>
++#include <linux/kernel.h>
++#include <linux/export.h>
++#include <linux/bitops.h>
++#include <linux/string.h>
++#include <linux/cryptohash.h>
++#include <asm/unaligned.h>
++#include <crypto/chacha.h>
++
++static void chacha_permute(u32 *x, int nrounds)
++{
++ int i;
++
++ /* whitelist the allowed round counts */
++ WARN_ON_ONCE(nrounds != 20 && nrounds != 12);
++
++ for (i = 0; i < nrounds; i += 2) {
++ x[0] += x[4]; x[12] = rol32(x[12] ^ x[0], 16);
++ x[1] += x[5]; x[13] = rol32(x[13] ^ x[1], 16);
++ x[2] += x[6]; x[14] = rol32(x[14] ^ x[2], 16);
++ x[3] += x[7]; x[15] = rol32(x[15] ^ x[3], 16);
++
++ x[8] += x[12]; x[4] = rol32(x[4] ^ x[8], 12);
++ x[9] += x[13]; x[5] = rol32(x[5] ^ x[9], 12);
++ x[10] += x[14]; x[6] = rol32(x[6] ^ x[10], 12);
++ x[11] += x[15]; x[7] = rol32(x[7] ^ x[11], 12);
++
++ x[0] += x[4]; x[12] = rol32(x[12] ^ x[0], 8);
++ x[1] += x[5]; x[13] = rol32(x[13] ^ x[1], 8);
++ x[2] += x[6]; x[14] = rol32(x[14] ^ x[2], 8);
++ x[3] += x[7]; x[15] = rol32(x[15] ^ x[3], 8);
++
++ x[8] += x[12]; x[4] = rol32(x[4] ^ x[8], 7);
++ x[9] += x[13]; x[5] = rol32(x[5] ^ x[9], 7);
++ x[10] += x[14]; x[6] = rol32(x[6] ^ x[10], 7);
++ x[11] += x[15]; x[7] = rol32(x[7] ^ x[11], 7);
++
++ x[0] += x[5]; x[15] = rol32(x[15] ^ x[0], 16);
++ x[1] += x[6]; x[12] = rol32(x[12] ^ x[1], 16);
++ x[2] += x[7]; x[13] = rol32(x[13] ^ x[2], 16);
++ x[3] += x[4]; x[14] = rol32(x[14] ^ x[3], 16);
++
++ x[10] += x[15]; x[5] = rol32(x[5] ^ x[10], 12);
++ x[11] += x[12]; x[6] = rol32(x[6] ^ x[11], 12);
++ x[8] += x[13]; x[7] = rol32(x[7] ^ x[8], 12);
++ x[9] += x[14]; x[4] = rol32(x[4] ^ x[9], 12);
++
++ x[0] += x[5]; x[15] = rol32(x[15] ^ x[0], 8);
++ x[1] += x[6]; x[12] = rol32(x[12] ^ x[1], 8);
++ x[2] += x[7]; x[13] = rol32(x[13] ^ x[2], 8);
++ x[3] += x[4]; x[14] = rol32(x[14] ^ x[3], 8);
++
++ x[10] += x[15]; x[5] = rol32(x[5] ^ x[10], 7);
++ x[11] += x[12]; x[6] = rol32(x[6] ^ x[11], 7);
++ x[8] += x[13]; x[7] = rol32(x[7] ^ x[8], 7);
++ x[9] += x[14]; x[4] = rol32(x[4] ^ x[9], 7);
++ }
++}
++
++/**
++ * chacha_block - generate one keystream block and increment block counter
++ * @state: input state matrix (16 32-bit words)
++ * @stream: output keystream block (64 bytes)
++ * @nrounds: number of rounds (20 or 12; 20 is recommended)
++ *
++ * This is the ChaCha core, a function from 64-byte strings to 64-byte strings.
++ * The caller has already converted the endianness of the input. This function
++ * also handles incrementing the block counter in the input matrix.
++ */
++void chacha_block_generic(u32 *state, u8 *stream, int nrounds)
++{
++ u32 x[16];
++ int i;
++
++ memcpy(x, state, 64);
++
++ chacha_permute(x, nrounds);
++
++ for (i = 0; i < ARRAY_SIZE(x); i++)
++ put_unaligned_le32(x[i] + state[i], &stream[i * sizeof(u32)]);
++
++ state[12]++;
++}
++EXPORT_SYMBOL(chacha_block_generic);
++
++/**
++ * hchacha_block_generic - abbreviated ChaCha core, for XChaCha
++ * @state: input state matrix (16 32-bit words)
++ * @out: output (8 32-bit words)
++ * @nrounds: number of rounds (20 or 12; 20 is recommended)
++ *
++ * HChaCha is the ChaCha equivalent of HSalsa and is an intermediate step
++ * towards XChaCha (see https://cr.yp.to/snuffle/xsalsa-20081128.pdf). HChaCha
++ * skips the final addition of the initial state, and outputs only certain words
++ * of the state. It should not be used for streaming directly.
++ */
++void hchacha_block_generic(const u32 *state, u32 *stream, int nrounds)
++{
++ u32 x[16];
++
++ memcpy(x, state, 64);
++
++ chacha_permute(x, nrounds);
++
++ memcpy(&stream[0], &x[0], 16);
++ memcpy(&stream[4], &x[12], 16);
++}
++EXPORT_SYMBOL(hchacha_block_generic);
+--- /dev/null
++++ b/lib/crypto/libchacha.c
+@@ -0,0 +1,35 @@
++// SPDX-License-Identifier: GPL-2.0-or-later
++/*
++ * The ChaCha stream cipher (RFC7539)
++ *
++ * Copyright (C) 2015 Martin Willi
++ */
++
++#include <linux/kernel.h>
++#include <linux/export.h>
++#include <linux/module.h>
++
++#include <crypto/algapi.h> // for crypto_xor_cpy
++#include <crypto/chacha.h>
++
++void chacha_crypt_generic(u32 *state, u8 *dst, const u8 *src,
++ unsigned int bytes, int nrounds)
++{
++ /* aligned to potentially speed up crypto_xor() */
++ u8 stream[CHACHA_BLOCK_SIZE] __aligned(sizeof(long));
++
++ while (bytes >= CHACHA_BLOCK_SIZE) {
++ chacha_block_generic(state, stream, nrounds);
++ crypto_xor_cpy(dst, src, stream, CHACHA_BLOCK_SIZE);
++ bytes -= CHACHA_BLOCK_SIZE;
++ dst += CHACHA_BLOCK_SIZE;
++ src += CHACHA_BLOCK_SIZE;
++ }
++ if (bytes) {
++ chacha_block_generic(state, stream, nrounds);
++ crypto_xor_cpy(dst, src, stream, bytes);
++ }
++}
++EXPORT_SYMBOL(chacha_crypt_generic);
++
++MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.25.1) at 2025-03-31 05:21:54 +0000