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 EVP_CIPHER_CTX_init(&cipher->ctx);
43 cipher_t *cipher_open_by_name(const char *name) {
44 const EVP_CIPHER *evp_cipher = EVP_get_cipherbyname(name);
46 logger(DEBUG_ALWAYS, LOG_ERR, "Unknown cipher name '%s'!", name);
50 return cipher_open(evp_cipher);
53 cipher_t *cipher_open_by_nid(int nid) {
54 const EVP_CIPHER *evp_cipher = EVP_get_cipherbynid(nid);
56 logger(DEBUG_ALWAYS, LOG_ERR, "Unknown cipher nid %d!", nid);
60 return cipher_open(evp_cipher);
63 cipher_t *cipher_open_blowfish_ofb(void) {
64 return cipher_open(EVP_bf_ofb());
67 void cipher_close(cipher_t *cipher) {
71 EVP_CIPHER_CTX_cleanup(&cipher->ctx);
75 size_t cipher_keylength(const cipher_t *cipher) {
76 if(!cipher || !cipher->cipher)
79 return cipher->cipher->key_len + cipher->cipher->iv_len;
82 size_t cipher_blocksize(const cipher_t *cipher) {
83 if(!cipher || !cipher->cipher)
86 return cipher->cipher->block_size;
89 bool cipher_set_key(cipher_t *cipher, void *key, bool encrypt) {
93 result = EVP_EncryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, (unsigned char *)key + cipher->cipher->key_len);
95 result = EVP_DecryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, (unsigned char *)key + cipher->cipher->key_len);
100 logger(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
104 bool cipher_set_key_from_rsa(cipher_t *cipher, void *key, size_t len, bool encrypt) {
108 result = EVP_EncryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key + len - cipher->cipher->key_len, (unsigned char *)key + len - cipher->cipher->iv_len - cipher->cipher->key_len);
110 result = EVP_DecryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key + len - cipher->cipher->key_len, (unsigned char *)key + len - cipher->cipher->iv_len - cipher->cipher->key_len);
115 logger(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
119 bool cipher_encrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen, bool oneshot) {
122 if(EVP_EncryptInit_ex(&cipher->ctx, NULL, NULL, NULL, NULL)
123 && EVP_EncryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, indata, inlen)
124 && EVP_EncryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
125 if(outlen) *outlen = len + pad;
130 if(EVP_EncryptUpdate(&cipher->ctx, outdata, &len, indata, inlen)) {
131 if(outlen) *outlen = len;
136 logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
140 bool cipher_decrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen, bool oneshot) {
143 if(EVP_DecryptInit_ex(&cipher->ctx, NULL, NULL, NULL, NULL)
144 && EVP_DecryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, indata, inlen)
145 && EVP_DecryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
146 if(outlen) *outlen = len + pad;
151 if(EVP_EncryptUpdate(&cipher->ctx, outdata, &len, indata, inlen)) {
152 if(outlen) *outlen = len;
157 logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
161 int cipher_get_nid(const cipher_t *cipher) {
162 if(!cipher || !cipher->cipher)
165 return cipher->cipher->nid;
168 bool cipher_active(const cipher_t *cipher) {
169 return cipher && cipher->cipher && cipher->cipher->nid != 0;