1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Common values for the ChaCha20 algorithm 4 */ 5 6 #ifndef _CRYPTO_CHACHA20_H 7 #define _CRYPTO_CHACHA20_H 8 9 #include <crypto/skcipher.h> 10 #include <linux/types.h> 11 #include <linux/crypto.h> 12 13 #define CHACHA20_IV_SIZE 16 14 #define CHACHA20_KEY_SIZE 32 15 #define CHACHA20_BLOCK_SIZE 64 16 17 struct chacha20_ctx { 18 u32 key[8]; 19 }; 20 21 void chacha20_block(u32 *state, u8 *stream); 22 void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv); 23 int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key, 24 unsigned int keysize); 25 int crypto_chacha20_crypt(struct skcipher_request *req); 26 27 enum chacha_constants { /* expand 32-byte k */ 28 CHACHA_CONSTANT_EXPA = 0x61707865U, 29 CHACHA_CONSTANT_ND_3 = 0x3320646eU, 30 CHACHA_CONSTANT_2_BY = 0x79622d32U, 31 CHACHA_CONSTANT_TE_K = 0x6b206574U 32 }; 33 chacha_init_consts(u32 * state)34static inline void chacha_init_consts(u32 *state) 35 { 36 state[0] = CHACHA_CONSTANT_EXPA; 37 state[1] = CHACHA_CONSTANT_ND_3; 38 state[2] = CHACHA_CONSTANT_2_BY; 39 state[3] = CHACHA_CONSTANT_TE_K; 40 } 41 42 #endif 43