GNUnet 0.22.2
crypto_symmetric.c
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1/*
2 This file is part of GNUnet.
3 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2013 GNUnet e.V.
4
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your option) any later version.
9
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Affero General Public License for more details.
14
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
17
18 SPDX-License-Identifier: AGPL3.0-or-later
19 */
20
29#include "platform.h"
30#include "gnunet_util_lib.h"
31#include <gcrypt.h>
32
33#define LOG(kind, ...) GNUNET_log_from (kind, "util-crypto-symmetric", \
34 __VA_ARGS__)
35
41void
42GNUNET_CRYPTO_symmetric_create_session_key (struct
43 GNUNET_CRYPTO_SymmetricSessionKey *
44 key)
45{
46 gcry_randomize (key->aes_key,
47 GNUNET_CRYPTO_AES_KEY_LENGTH,
48 GCRY_STRONG_RANDOM);
49 gcry_randomize (key->twofish_key,
50 GNUNET_CRYPTO_AES_KEY_LENGTH,
51 GCRY_STRONG_RANDOM);
52}
53
54
63static int
64setup_cipher_aes (gcry_cipher_hd_t *handle,
65 const struct GNUNET_CRYPTO_SymmetricSessionKey *sessionkey,
66 const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv)
67{
68 int rc;
69
70 GNUNET_assert (0 ==
71 gcry_cipher_open (handle, GCRY_CIPHER_AES256,
72 GCRY_CIPHER_MODE_CFB, 0));
73 rc = gcry_cipher_setkey (*handle,
74 sessionkey->aes_key,
75 sizeof(sessionkey->aes_key));
76 GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
77 rc = gcry_cipher_setiv (*handle,
78 iv->aes_iv,
79 sizeof(iv->aes_iv));
80 GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
81 return GNUNET_OK;
82}
83
84
93static int
94setup_cipher_twofish (gcry_cipher_hd_t *handle,
95 const struct
96 GNUNET_CRYPTO_SymmetricSessionKey *sessionkey,
97 const struct
98 GNUNET_CRYPTO_SymmetricInitializationVector *iv)
99{
100 int rc;
101
102 GNUNET_assert (0 ==
103 gcry_cipher_open (handle, GCRY_CIPHER_TWOFISH,
104 GCRY_CIPHER_MODE_CFB, 0));
105 rc = gcry_cipher_setkey (*handle,
106 sessionkey->twofish_key,
107 sizeof(sessionkey->twofish_key));
108 GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
109 rc = gcry_cipher_setiv (*handle,
110 iv->twofish_iv,
111 sizeof(iv->twofish_iv));
112 GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
113 return GNUNET_OK;
114}
115
116
130ssize_t
131GNUNET_CRYPTO_symmetric_encrypt (const void *block,
132 size_t size,
133 const struct
134 GNUNET_CRYPTO_SymmetricSessionKey *sessionkey,
135 const struct
136 GNUNET_CRYPTO_SymmetricInitializationVector *iv,
137 void *result)
138{
139 gcry_cipher_hd_t handle;
140 char tmp[GNUNET_NZL(size)];
141
142 if (GNUNET_OK != setup_cipher_aes (&handle, sessionkey, iv))
143 return -1;
144 GNUNET_assert (0 == gcry_cipher_encrypt (handle, tmp, size, block, size));
145 gcry_cipher_close (handle);
146 if (GNUNET_OK != setup_cipher_twofish (&handle, sessionkey, iv))
147 return -1;
148 GNUNET_assert (0 == gcry_cipher_encrypt (handle, result, size, tmp, size));
149 gcry_cipher_close (handle);
150 memset (tmp, 0, sizeof(tmp));
151 return size;
152}
153
154
168ssize_t
169GNUNET_CRYPTO_symmetric_decrypt (const void *block,
170 size_t size,
171 const struct
172 GNUNET_CRYPTO_SymmetricSessionKey *sessionkey,
173 const struct
174 GNUNET_CRYPTO_SymmetricInitializationVector *iv,
175 void *result)
176{
177 gcry_cipher_hd_t handle;
178 char tmp[size];
179
180 if (GNUNET_OK != setup_cipher_twofish (&handle, sessionkey, iv))
181 return -1;
182 GNUNET_assert (0 == gcry_cipher_decrypt (handle, tmp, size, block, size));
183 gcry_cipher_close (handle);
184 if (GNUNET_OK != setup_cipher_aes (&handle, sessionkey, iv))
185 return -1;
186 GNUNET_assert (0 == gcry_cipher_decrypt (handle, result, size, tmp, size));
187 gcry_cipher_close (handle);
188 memset (tmp, 0, sizeof(tmp));
189 return size;
190}
191
192
202void
203GNUNET_CRYPTO_symmetric_derive_iv (struct
204 GNUNET_CRYPTO_SymmetricInitializationVector *
205 iv,
206 const struct
207 GNUNET_CRYPTO_SymmetricSessionKey *skey,
208 const void *salt,
209 size_t salt_len,
210 ...)
211{
212 va_list argp;
213
214 va_start (argp, salt_len);
215 GNUNET_CRYPTO_symmetric_derive_iv_v (iv, skey, salt, salt_len, argp);
216 va_end (argp);
217}
218
219
220void
221GNUNET_CRYPTO_symmetric_derive_iv_v (struct
222 GNUNET_CRYPTO_SymmetricInitializationVector
223 *iv,
224 const struct
225 GNUNET_CRYPTO_SymmetricSessionKey *skey,
226 const void *salt,
227 size_t salt_len,
228 va_list argp)
229{
230 char aes_salt[salt_len + 4];
231 char twofish_salt[salt_len + 4];
232
233 GNUNET_memcpy (aes_salt, salt, salt_len);
234 GNUNET_memcpy (&aes_salt[salt_len], "AES!", 4);
235 GNUNET_memcpy (twofish_salt, salt, salt_len);
236 GNUNET_memcpy (&twofish_salt[salt_len], "FISH", 4);
237 GNUNET_CRYPTO_kdf_v (iv->aes_iv,
238 sizeof(iv->aes_iv),
239 aes_salt,
240 salt_len + 4,
241 skey->aes_key,
242 sizeof(skey->aes_key),
243 argp);
244 GNUNET_CRYPTO_kdf_v (iv->twofish_iv,
245 sizeof(iv->twofish_iv),
246 twofish_salt,
247 salt_len + 4,
248 skey->twofish_key,
249 sizeof(skey->twofish_key),
250 argp);
251}
252
253
254/* end of crypto_symmetric.c */
setup_cipher_aes
static int setup_cipher_aes(gcry_cipher_hd_t *handle, const struct GNUNET_CRYPTO_SymmetricSessionKey *sessionkey, const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv)
Initialize AES cipher.
Definition: crypto_symmetric.c:64
setup_cipher_twofish
static int setup_cipher_twofish(gcry_cipher_hd_t *handle, const struct GNUNET_CRYPTO_SymmetricSessionKey *sessionkey, const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv)
Initialize TWOFISH cipher.
Definition: crypto_symmetric.c:94
key
struct GNUNET_HashCode key
The key used in the DHT.
Definition: gnunet-dht-put.c:37
result
static int result
Global testing status.
Definition: gnunet-regex-profiler.c:240
salt
static struct GNUNET_CRYPTO_PowSalt salt
Salt for PoW calculations.
Definition: gnunet-scrypt.c:34
handle
static struct GNUNET_VPN_Handle * handle
Handle to vpn service.
Definition: gnunet-vpn.c:35
gnunet_util_lib.h
GNUNET_CRYPTO_symmetric_create_session_key
void GNUNET_CRYPTO_symmetric_create_session_key(struct GNUNET_CRYPTO_SymmetricSessionKey *key)
Create a new SessionKey (for symmetric encryption).
Definition: crypto_symmetric.c:42
GNUNET_CRYPTO_symmetric_encrypt
ssize_t GNUNET_CRYPTO_symmetric_encrypt(const void *block, size_t size, const struct GNUNET_CRYPTO_SymmetricSessionKey *sessionkey, const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv, void *result)
Encrypt a block with a symmetric session key.
Definition: crypto_symmetric.c:131
GNUNET_CRYPTO_symmetric_derive_iv
void GNUNET_CRYPTO_symmetric_derive_iv(struct GNUNET_CRYPTO_SymmetricInitializationVector *iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *skey, const void *salt, size_t salt_len,...)
Derive an IV.
Definition: crypto_symmetric.c:203
GNUNET_CRYPTO_symmetric_decrypt
ssize_t GNUNET_CRYPTO_symmetric_decrypt(const void *block, size_t size, const struct GNUNET_CRYPTO_SymmetricSessionKey *sessionkey, const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv, void *result)
Decrypt a given block with the session key.
Definition: crypto_symmetric.c:169
GNUNET_NZL
#define GNUNET_NZL(l)
Macro used to avoid using 0 for the length of a variable-size array (Non-Zero-Length).
Definition: gnunet_common.h:232
GNUNET_CRYPTO_AES_KEY_LENGTH
#define GNUNET_CRYPTO_AES_KEY_LENGTH
length of the sessionkey in bytes (256 BIT sessionkey)
Definition: gnunet_crypto_lib.h:110
GNUNET_CRYPTO_kdf_v
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_kdf_v(void *result, size_t out_len, const void *xts, size_t xts_len, const void *skm, size_t skm_len, va_list argp)
Derive key.
Definition: crypto_kdf.c:38
GNUNET_CRYPTO_symmetric_derive_iv_v
void GNUNET_CRYPTO_symmetric_derive_iv_v(struct GNUNET_CRYPTO_SymmetricInitializationVector *iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *skey, const void *salt, size_t salt_len, va_list argp)
Derive an IV.
Definition: crypto_symmetric.c:221
GNUNET_memcpy
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
Definition: gnunet_common.h:1316
GNUNET_OK
@ GNUNET_OK
Definition: gnunet_common.h:111
GNUNET_assert
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
Definition: gnunet_common.h:956
size
static unsigned int size
Size of the "table".
Definition: peer.c:68
GNUNET_CRYPTO_SymmetricInitializationVector
IV for sym cipher.
Definition: gnunet_crypto_lib.h:512
GNUNET_CRYPTO_SymmetricInitializationVector::aes_iv
unsigned char aes_iv[(256/8)/2]
Definition: gnunet_crypto_lib.h:513
GNUNET_CRYPTO_SymmetricInitializationVector::twofish_iv
unsigned char twofish_iv[(256/8)/2]
Definition: gnunet_crypto_lib.h:515
GNUNET_CRYPTO_SymmetricSessionKey
type for session keys
Definition: gnunet_crypto_lib.h:480
GNUNET_CRYPTO_SymmetricSessionKey::twofish_key
unsigned char twofish_key[(256/8)]
Actual key for TwoFish.
Definition: gnunet_crypto_lib.h:489
GNUNET_CRYPTO_SymmetricSessionKey::aes_key
unsigned char aes_key[(256/8)]
Actual key for AES.
Definition: gnunet_crypto_lib.h:484