1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * The ChaCha stream cipher (RFC7539) 4 * 5 * Copyright (C) 2015 Martin Willi 6 */ 7 8 #include <crypto/algapi.h> // for crypto_xor_cpy 9 #include <crypto/chacha.h> 10 #include <linux/export.h> 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 14 static void __maybe_unused 15 chacha_crypt_generic(struct chacha_state *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 } 33 34 #ifdef CONFIG_CRYPTO_LIB_CHACHA_ARCH 35 #include "chacha.h" /* $(SRCARCH)/chacha.h */ 36 #else 37 #define chacha_crypt_arch chacha_crypt_generic 38 #define hchacha_block_arch hchacha_block_generic 39 #endif 40 41 void chacha_crypt(struct chacha_state *state, u8 *dst, const u8 *src, 42 unsigned int bytes, int nrounds) 43 { 44 chacha_crypt_arch(state, dst, src, bytes, nrounds); 45 } 46 EXPORT_SYMBOL_GPL(chacha_crypt); 47 48 void hchacha_block(const struct chacha_state *state, 49 u32 out[HCHACHA_OUT_WORDS], int nrounds) 50 { 51 hchacha_block_arch(state, out, nrounds); 52 } 53 EXPORT_SYMBOL_GPL(hchacha_block); 54 55 #ifdef chacha_mod_init_arch 56 static int __init chacha_mod_init(void) 57 { 58 chacha_mod_init_arch(); 59 return 0; 60 } 61 subsys_initcall(chacha_mod_init); 62 63 static void __exit chacha_mod_exit(void) 64 { 65 } 66 module_exit(chacha_mod_exit); 67 #endif 68 69 MODULE_DESCRIPTION("ChaCha stream cipher (RFC7539)"); 70 MODULE_LICENSE("GPL"); 71