e_chacha.c revision 1.6
1/* $OpenBSD: e_chacha.c,v 1.6 2020/01/26 02:39:58 tb Exp $ */ 2/* 3 * Copyright (c) 2014 Joel Sing <jsing@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18#include <openssl/opensslconf.h> 19 20#ifndef OPENSSL_NO_CHACHA 21 22#include <openssl/chacha.h> 23#include <openssl/evp.h> 24#include <openssl/objects.h> 25 26#include "evp_locl.h" 27 28static int chacha_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, 29 const unsigned char *in, size_t len); 30static int chacha_init(EVP_CIPHER_CTX *ctx, const unsigned char *key, 31 const unsigned char *iv, int enc); 32 33static const EVP_CIPHER chacha20_cipher = { 34 .nid = NID_chacha20, 35 .block_size = 1, 36 .key_len = 32, 37 .iv_len = 16, /* OpenSSL has 8 byte counter followed by 8 byte iv */ 38 .flags = EVP_CIPH_STREAM_CIPHER | EVP_CIPH_ALWAYS_CALL_INIT | 39 EVP_CIPH_CUSTOM_IV, 40 .init = chacha_init, 41 .do_cipher = chacha_cipher, 42 .ctx_size = sizeof(ChaCha_ctx) 43}; 44 45const EVP_CIPHER * 46EVP_chacha20(void) 47{ 48 return (&chacha20_cipher); 49} 50 51static int 52chacha_init(EVP_CIPHER_CTX *ctx, const unsigned char *key, 53 const unsigned char *iv, int enc) 54{ 55 if (key != NULL) 56 ChaCha_set_key((ChaCha_ctx *)ctx->cipher_data, key, 57 EVP_CIPHER_CTX_key_length(ctx) * 8); 58 if (iv != NULL) { 59 const unsigned char *openssl_iv = iv + 8; 60 const unsigned char *counter = iv; 61 62 ChaCha_set_iv((ChaCha_ctx *)ctx->cipher_data, openssl_iv, 63 counter); 64 } 65 return 1; 66} 67 68static int 69chacha_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in, 70 size_t len) 71{ 72 ChaCha((ChaCha_ctx *)ctx->cipher_data, out, in, len); 73 return 1; 74} 75 76#endif 77