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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * The ChaCha stream cipher (RFC7539)4 *5 * Copyright (C) 2015 Martin Willi6 */7 8#include <linux/kernel.h>9#include <linux/export.h>10#include <linux/module.h>11 12#include <crypto/algapi.h> // for crypto_xor_cpy13#include <crypto/chacha.h>14 15void chacha_crypt_generic(u32 *state, u8 *dst, const u8 *src,16 unsigned int bytes, int nrounds)17{18 /* aligned to potentially speed up crypto_xor() */19 u8 stream[CHACHA_BLOCK_SIZE] __aligned(sizeof(long));20 21 while (bytes >= CHACHA_BLOCK_SIZE) {22 chacha_block_generic(state, stream, nrounds);23 crypto_xor_cpy(dst, src, stream, CHACHA_BLOCK_SIZE);24 bytes -= CHACHA_BLOCK_SIZE;25 dst += CHACHA_BLOCK_SIZE;26 src += CHACHA_BLOCK_SIZE;27 }28 if (bytes) {29 chacha_block_generic(state, stream, nrounds);30 crypto_xor_cpy(dst, src, stream, bytes);31 }32}33EXPORT_SYMBOL(chacha_crypt_generic);34 35MODULE_DESCRIPTION("ChaCha stream cipher (RFC7539)");36MODULE_LICENSE("GPL");37