2 cipher.c -- Symmetric block cipher handling
3 Copyright (C) 2007-2013 Guus Sliepen <guus@tinc-vpn.org>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20 #include "../system.h"
22 #include <openssl/rand.h>
23 #include <openssl/err.h>
24 #include <openssl/evp.h>
26 #include "../cipher.h"
27 #include "../logger.h"
28 #include "../xalloc.h"
32 const EVP_CIPHER *cipher;
35 static cipher_t *cipher_open(const EVP_CIPHER *evp_cipher) {
36 cipher_t *cipher = xzalloc(sizeof *cipher);
37 cipher->cipher = evp_cipher;
38 cipher->ctx = EVP_CIPHER_CTX_new();
45 cipher_t *cipher_open_by_name(const char *name) {
46 const EVP_CIPHER *evp_cipher = EVP_get_cipherbyname(name);
48 logger(DEBUG_ALWAYS, LOG_ERR, "Unknown cipher name '%s'!", name);
52 return cipher_open(evp_cipher);
55 cipher_t *cipher_open_by_nid(int nid) {
56 const EVP_CIPHER *evp_cipher = EVP_get_cipherbynid(nid);
58 logger(DEBUG_ALWAYS, LOG_ERR, "Unknown cipher nid %d!", nid);
62 return cipher_open(evp_cipher);
65 cipher_t *cipher_open_blowfish_ofb(void) {
66 return cipher_open(EVP_bf_ofb());
69 void cipher_close(cipher_t *cipher) {
73 EVP_CIPHER_CTX_free(cipher->ctx);
77 size_t cipher_keylength(const cipher_t *cipher) {
78 if(!cipher || !cipher->cipher)
81 return EVP_CIPHER_key_length(cipher->cipher) + EVP_CIPHER_iv_length(cipher->cipher);
84 size_t cipher_blocksize(const cipher_t *cipher) {
85 if(!cipher || !cipher->cipher)
88 return EVP_CIPHER_block_size(cipher->cipher);
91 bool cipher_set_key(cipher_t *cipher, void *key, bool encrypt) {
95 result = EVP_EncryptInit_ex(cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, (unsigned char *)key + EVP_CIPHER_key_length(cipher->cipher));
97 result = EVP_DecryptInit_ex(cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, (unsigned char *)key + EVP_CIPHER_key_length(cipher->cipher));
102 logger(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
106 bool cipher_set_key_from_rsa(cipher_t *cipher, void *key, size_t len, bool encrypt) {
110 result = EVP_EncryptInit_ex(cipher->ctx, cipher->cipher, NULL, (unsigned char *)key + len - EVP_CIPHER_key_length(cipher->cipher), (unsigned char *)key + len - EVP_CIPHER_iv_length(cipher->cipher) - EVP_CIPHER_key_length(cipher->cipher));
112 result = EVP_DecryptInit_ex(cipher->ctx, cipher->cipher, NULL, (unsigned char *)key + len - EVP_CIPHER_key_length(cipher->cipher), (unsigned char *)key + len - EVP_CIPHER_iv_length(cipher->cipher) - EVP_CIPHER_key_length(cipher->cipher));
117 logger(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
121 bool cipher_encrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen, bool oneshot) {
124 if(EVP_EncryptInit_ex(cipher->ctx, NULL, NULL, NULL, NULL)
125 && EVP_EncryptUpdate(cipher->ctx, (unsigned char *)outdata, &len, indata, inlen)
126 && EVP_EncryptFinal(cipher->ctx, (unsigned char *)outdata + len, &pad)) {
127 if(outlen) *outlen = len + pad;
132 if(EVP_EncryptUpdate(cipher->ctx, outdata, &len, indata, inlen)) {
133 if(outlen) *outlen = len;
138 logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
142 bool cipher_decrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen, bool oneshot) {
145 if(EVP_DecryptInit_ex(cipher->ctx, NULL, NULL, NULL, NULL)
146 && EVP_DecryptUpdate(cipher->ctx, (unsigned char *)outdata, &len, indata, inlen)
147 && EVP_DecryptFinal(cipher->ctx, (unsigned char *)outdata + len, &pad)) {
148 if(outlen) *outlen = len + pad;
153 if(EVP_EncryptUpdate(cipher->ctx, outdata, &len, indata, inlen)) {
154 if(outlen) *outlen = len;
159 logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
163 int cipher_get_nid(const cipher_t *cipher) {
164 if(!cipher || !cipher->cipher)
167 return EVP_CIPHER_nid(cipher->cipher);
170 bool cipher_active(const cipher_t *cipher) {
171 return cipher && cipher->cipher && EVP_CIPHER_nid(cipher->cipher) != 0;