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;
33 struct cipher_counter *counter;
36 typedef struct cipher_counter {
37 unsigned char counter[CIPHER_MAX_IV_SIZE];
38 unsigned char block[CIPHER_MAX_IV_SIZE];
42 static cipher_t *cipher_open(const EVP_CIPHER *evp_cipher) {
43 cipher_t *cipher = xzalloc(sizeof *cipher);
44 cipher->cipher = evp_cipher;
45 EVP_CIPHER_CTX_init(&cipher->ctx);
50 cipher_t *cipher_open_by_name(const char *name) {
51 const EVP_CIPHER *evp_cipher = EVP_get_cipherbyname(name);
53 logger(DEBUG_ALWAYS, LOG_ERR, "Unknown cipher name '%s'!", name);
57 return cipher_open(evp_cipher);
60 cipher_t *cipher_open_by_nid(int nid) {
61 const EVP_CIPHER *evp_cipher = EVP_get_cipherbynid(nid);
63 logger(DEBUG_ALWAYS, LOG_ERR, "Unknown cipher nid %d!", nid);
67 return cipher_open(evp_cipher);
70 cipher_t *cipher_open_blowfish_ofb(void) {
71 return cipher_open(EVP_bf_ofb());
74 void cipher_close(cipher_t *cipher) {
78 EVP_CIPHER_CTX_cleanup(&cipher->ctx);
79 free(cipher->counter);
83 size_t cipher_keylength(const cipher_t *cipher) {
84 if(!cipher || !cipher->cipher)
87 return cipher->cipher->key_len + cipher->cipher->iv_len;
90 bool cipher_set_key(cipher_t *cipher, void *key, bool encrypt) {
94 result = EVP_EncryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, (unsigned char *)key + cipher->cipher->key_len);
96 result = EVP_DecryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, (unsigned char *)key + cipher->cipher->key_len);
101 logger(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
105 bool cipher_set_key_from_rsa(cipher_t *cipher, void *key, size_t len, bool encrypt) {
109 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);
111 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);
116 logger(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
120 bool cipher_set_counter(cipher_t *cipher, const void *counter, size_t len) {
121 if(len > cipher->cipher->iv_len - 4) {
122 logger(DEBUG_ALWAYS, LOG_ERR, "Counter too long");
126 memcpy(cipher->counter->counter, counter, len);
127 cipher->counter->n = 0;
132 bool cipher_set_counter_key(cipher_t *cipher, void *key) {
133 int result = EVP_EncryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, NULL);
135 logger(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
140 cipher->counter = xzalloc(sizeof *cipher->counter);
142 cipher->counter->n = 0;
144 memcpy(cipher->counter->counter, (unsigned char *)key + cipher->cipher->key_len, cipher->cipher->iv_len);
149 bool cipher_gcm_encrypt_start(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen) {
151 if(!EVP_EncryptInit_ex(&cipher->ctx, NULL, NULL, NULL, cipher->counter->counter)
152 || (inlen && !EVP_EncryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, (unsigned char *)indata, inlen))) {
153 logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
161 bool cipher_gcm_encrypt_finish(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen) {
162 int len = 0, pad = 0;
163 if(!(inlen && EVP_EncryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, (unsigned char *)indata, inlen))
164 || !EVP_EncryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
165 logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
168 EVP_CIPHER_CTX_ctrl(&cipher->ctx, EVP_CTRL_GCM_GET_TAG, 16, (unsigned char *)outdata + len + pad);
170 *outlen = len + pad + 16;
174 bool cipher_gcm_encrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen) {
175 int len = 0, pad = 0;
176 if(!EVP_EncryptInit_ex(&cipher->ctx, NULL, NULL, NULL, cipher->counter->counter) ||
177 !EVP_EncryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, (unsigned char *)indata, inlen) ||
178 !EVP_EncryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
179 logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
182 EVP_CIPHER_CTX_ctrl(&cipher->ctx, EVP_CTRL_GCM_GET_TAG, 16, (unsigned char *)outdata + len + pad);
184 *outlen = len + pad + 16;
188 bool cipher_gcm_decrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen) {
192 int len = 0, pad = 0;
193 if(!EVP_DecryptInit_ex(&cipher->ctx, NULL, NULL, NULL, cipher->counter->counter)) {
194 logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
198 EVP_CIPHER_CTX_ctrl(&cipher->ctx, EVP_CTRL_GCM_SET_TAG, 16, (unsigned char *)indata + inlen - 16);
200 if(!EVP_DecryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, (unsigned char *)indata, inlen - 16) ||
201 !EVP_DecryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
202 logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
210 bool cipher_gcm_decrypt_start(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen) {
212 if(!EVP_DecryptInit_ex(&cipher->ctx, NULL, NULL, NULL, cipher->counter->counter)
213 || (inlen && !EVP_DecryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, (unsigned char *)indata, inlen))) {
214 logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
222 bool cipher_gcm_decrypt_finish(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen) {
226 EVP_CIPHER_CTX_ctrl(&cipher->ctx, EVP_CTRL_GCM_SET_TAG, 16, (unsigned char *)indata + inlen - 16);
228 int len = 0, pad = 0;
229 if((inlen > 16 && !EVP_DecryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, (unsigned char *)indata, inlen - 16))
230 || !EVP_DecryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
231 logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
238 bool cipher_encrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen, bool oneshot) {
241 if(EVP_EncryptInit_ex(&cipher->ctx, NULL, NULL, NULL, NULL)
242 && EVP_EncryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, indata, inlen)
243 && EVP_EncryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
244 if(outlen) *outlen = len + pad;
249 if(EVP_EncryptUpdate(&cipher->ctx, outdata, &len, indata, inlen)) {
250 if(outlen) *outlen = len;
255 logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
259 bool cipher_decrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen, bool oneshot) {
262 if(EVP_DecryptInit_ex(&cipher->ctx, NULL, NULL, NULL, NULL)
263 && EVP_DecryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, indata, inlen)
264 && EVP_DecryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
265 if(outlen) *outlen = len + pad;
270 if(EVP_EncryptUpdate(&cipher->ctx, outdata, &len, indata, inlen)) {
271 if(outlen) *outlen = len;
276 logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
280 int cipher_get_nid(const cipher_t *cipher) {
281 if(!cipher || !cipher->cipher)
284 return cipher->cipher->nid;
287 bool cipher_active(const cipher_t *cipher) {
288 return cipher && cipher->cipher && cipher->cipher->nid != 0;