2 * QEMU Crypto cipher libgcrypt algorithms
4 * Copyright (c) 2015 Red Hat, Inc.
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
21 #include "qemu/osdep.h"
22 #include "crypto/xts.h"
27 bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg)
30 case QCRYPTO_CIPHER_ALG_DES_RFB:
31 case QCRYPTO_CIPHER_ALG_AES_128:
32 case QCRYPTO_CIPHER_ALG_AES_192:
33 case QCRYPTO_CIPHER_ALG_AES_256:
34 case QCRYPTO_CIPHER_ALG_CAST5_128:
35 case QCRYPTO_CIPHER_ALG_SERPENT_128:
36 case QCRYPTO_CIPHER_ALG_SERPENT_192:
37 case QCRYPTO_CIPHER_ALG_SERPENT_256:
38 case QCRYPTO_CIPHER_ALG_TWOFISH_128:
39 case QCRYPTO_CIPHER_ALG_TWOFISH_256:
46 typedef struct QCryptoCipherGcrypt QCryptoCipherGcrypt;
47 struct QCryptoCipherGcrypt {
48 gcry_cipher_hd_t handle;
49 gcry_cipher_hd_t tweakhandle;
54 QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
55 QCryptoCipherMode mode,
56 const uint8_t *key, size_t nkey,
59 QCryptoCipher *cipher;
60 QCryptoCipherGcrypt *ctx;
62 int gcryalg, gcrymode;
65 case QCRYPTO_CIPHER_MODE_ECB:
66 case QCRYPTO_CIPHER_MODE_XTS:
67 gcrymode = GCRY_CIPHER_MODE_ECB;
69 case QCRYPTO_CIPHER_MODE_CBC:
70 gcrymode = GCRY_CIPHER_MODE_CBC;
73 error_setg(errp, "Unsupported cipher mode %d", mode);
77 if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
82 case QCRYPTO_CIPHER_ALG_DES_RFB:
83 gcryalg = GCRY_CIPHER_DES;
86 case QCRYPTO_CIPHER_ALG_AES_128:
87 gcryalg = GCRY_CIPHER_AES128;
90 case QCRYPTO_CIPHER_ALG_AES_192:
91 gcryalg = GCRY_CIPHER_AES192;
94 case QCRYPTO_CIPHER_ALG_AES_256:
95 gcryalg = GCRY_CIPHER_AES256;
98 case QCRYPTO_CIPHER_ALG_CAST5_128:
99 gcryalg = GCRY_CIPHER_CAST5;
102 case QCRYPTO_CIPHER_ALG_SERPENT_128:
103 gcryalg = GCRY_CIPHER_SERPENT128;
106 case QCRYPTO_CIPHER_ALG_SERPENT_192:
107 gcryalg = GCRY_CIPHER_SERPENT192;
110 case QCRYPTO_CIPHER_ALG_SERPENT_256:
111 gcryalg = GCRY_CIPHER_SERPENT256;
114 case QCRYPTO_CIPHER_ALG_TWOFISH_128:
115 gcryalg = GCRY_CIPHER_TWOFISH128;
118 case QCRYPTO_CIPHER_ALG_TWOFISH_256:
119 gcryalg = GCRY_CIPHER_TWOFISH;
123 error_setg(errp, "Unsupported cipher algorithm %d", alg);
127 cipher = g_new0(QCryptoCipher, 1);
131 ctx = g_new0(QCryptoCipherGcrypt, 1);
133 err = gcry_cipher_open(&ctx->handle, gcryalg, gcrymode, 0);
135 error_setg(errp, "Cannot initialize cipher: %s",
139 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
140 err = gcry_cipher_open(&ctx->tweakhandle, gcryalg, gcrymode, 0);
142 error_setg(errp, "Cannot initialize cipher: %s",
148 if (cipher->alg == QCRYPTO_CIPHER_ALG_DES_RFB) {
149 /* We're using standard DES cipher from gcrypt, so we need
150 * to munge the key so that the results are the same as the
151 * bizarre RFB variant of DES :-)
153 uint8_t *rfbkey = qcrypto_cipher_munge_des_rfb_key(key, nkey);
154 err = gcry_cipher_setkey(ctx->handle, rfbkey, nkey);
158 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
160 err = gcry_cipher_setkey(ctx->handle, key, nkey);
162 error_setg(errp, "Cannot set key: %s",
166 err = gcry_cipher_setkey(ctx->tweakhandle, key + nkey, nkey);
168 err = gcry_cipher_setkey(ctx->handle, key, nkey);
171 error_setg(errp, "Cannot set key: %s",
175 switch (cipher->alg) {
176 case QCRYPTO_CIPHER_ALG_AES_128:
177 case QCRYPTO_CIPHER_ALG_AES_192:
178 case QCRYPTO_CIPHER_ALG_AES_256:
179 case QCRYPTO_CIPHER_ALG_SERPENT_128:
180 case QCRYPTO_CIPHER_ALG_SERPENT_192:
181 case QCRYPTO_CIPHER_ALG_SERPENT_256:
182 case QCRYPTO_CIPHER_ALG_TWOFISH_128:
183 case QCRYPTO_CIPHER_ALG_TWOFISH_256:
186 case QCRYPTO_CIPHER_ALG_CAST5_128:
190 g_assert_not_reached();
194 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
195 ctx->iv = g_new0(uint8_t, ctx->blocksize);
198 cipher->opaque = ctx;
202 gcry_cipher_close(ctx->handle);
203 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
204 gcry_cipher_close(ctx->tweakhandle);
212 void qcrypto_cipher_free(QCryptoCipher *cipher)
214 QCryptoCipherGcrypt *ctx;
218 ctx = cipher->opaque;
219 gcry_cipher_close(ctx->handle);
220 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
221 gcry_cipher_close(ctx->tweakhandle);
229 static void qcrypto_gcrypt_xts_encrypt(const void *ctx,
235 err = gcry_cipher_encrypt((gcry_cipher_hd_t)ctx, dst, length, src, length);
239 static void qcrypto_gcrypt_xts_decrypt(const void *ctx,
245 err = gcry_cipher_decrypt((gcry_cipher_hd_t)ctx, dst, length, src, length);
249 int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
255 QCryptoCipherGcrypt *ctx = cipher->opaque;
258 if (len % ctx->blocksize) {
259 error_setg(errp, "Length %zu must be a multiple of block size %zu",
260 len, ctx->blocksize);
264 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
265 xts_encrypt(ctx->handle, ctx->tweakhandle,
266 qcrypto_gcrypt_xts_encrypt,
267 qcrypto_gcrypt_xts_decrypt,
268 ctx->iv, len, out, in);
270 err = gcry_cipher_encrypt(ctx->handle,
274 error_setg(errp, "Cannot encrypt data: %s",
284 int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
290 QCryptoCipherGcrypt *ctx = cipher->opaque;
293 if (len % ctx->blocksize) {
294 error_setg(errp, "Length %zu must be a multiple of block size %zu",
295 len, ctx->blocksize);
299 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
300 xts_decrypt(ctx->handle, ctx->tweakhandle,
301 qcrypto_gcrypt_xts_encrypt,
302 qcrypto_gcrypt_xts_decrypt,
303 ctx->iv, len, out, in);
305 err = gcry_cipher_decrypt(ctx->handle,
309 error_setg(errp, "Cannot decrypt data: %s",
318 int qcrypto_cipher_setiv(QCryptoCipher *cipher,
319 const uint8_t *iv, size_t niv,
322 QCryptoCipherGcrypt *ctx = cipher->opaque;
325 if (niv != ctx->blocksize) {
326 error_setg(errp, "Expected IV size %zu not %zu",
327 ctx->blocksize, niv);
332 memcpy(ctx->iv, iv, niv);
334 gcry_cipher_reset(ctx->handle);
335 err = gcry_cipher_setiv(ctx->handle, iv, niv);
337 error_setg(errp, "Cannot set IV: %s",