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,
28 QCryptoCipherMode mode)
31 case QCRYPTO_CIPHER_ALG_DES_RFB:
32 case QCRYPTO_CIPHER_ALG_AES_128:
33 case QCRYPTO_CIPHER_ALG_AES_192:
34 case QCRYPTO_CIPHER_ALG_AES_256:
35 case QCRYPTO_CIPHER_ALG_CAST5_128:
36 case QCRYPTO_CIPHER_ALG_SERPENT_128:
37 case QCRYPTO_CIPHER_ALG_SERPENT_192:
38 case QCRYPTO_CIPHER_ALG_SERPENT_256:
39 case QCRYPTO_CIPHER_ALG_TWOFISH_128:
40 case QCRYPTO_CIPHER_ALG_TWOFISH_256:
47 case QCRYPTO_CIPHER_MODE_ECB:
48 case QCRYPTO_CIPHER_MODE_CBC:
49 case QCRYPTO_CIPHER_MODE_XTS:
50 case QCRYPTO_CIPHER_MODE_CTR:
57 typedef struct QCryptoCipherGcrypt QCryptoCipherGcrypt;
58 struct QCryptoCipherGcrypt {
59 gcry_cipher_hd_t handle;
60 gcry_cipher_hd_t tweakhandle;
62 /* Initialization vector or Counter */
66 QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
67 QCryptoCipherMode mode,
68 const uint8_t *key, size_t nkey,
71 QCryptoCipher *cipher;
72 QCryptoCipherGcrypt *ctx;
74 int gcryalg, gcrymode;
77 case QCRYPTO_CIPHER_MODE_ECB:
78 case QCRYPTO_CIPHER_MODE_XTS:
79 gcrymode = GCRY_CIPHER_MODE_ECB;
81 case QCRYPTO_CIPHER_MODE_CBC:
82 gcrymode = GCRY_CIPHER_MODE_CBC;
84 case QCRYPTO_CIPHER_MODE_CTR:
85 gcrymode = GCRY_CIPHER_MODE_CTR;
88 error_setg(errp, "Unsupported cipher mode %s",
89 QCryptoCipherMode_lookup[mode]);
93 if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
98 case QCRYPTO_CIPHER_ALG_DES_RFB:
99 gcryalg = GCRY_CIPHER_DES;
102 case QCRYPTO_CIPHER_ALG_AES_128:
103 gcryalg = GCRY_CIPHER_AES128;
106 case QCRYPTO_CIPHER_ALG_AES_192:
107 gcryalg = GCRY_CIPHER_AES192;
110 case QCRYPTO_CIPHER_ALG_AES_256:
111 gcryalg = GCRY_CIPHER_AES256;
114 case QCRYPTO_CIPHER_ALG_CAST5_128:
115 gcryalg = GCRY_CIPHER_CAST5;
118 case QCRYPTO_CIPHER_ALG_SERPENT_128:
119 gcryalg = GCRY_CIPHER_SERPENT128;
122 case QCRYPTO_CIPHER_ALG_SERPENT_192:
123 gcryalg = GCRY_CIPHER_SERPENT192;
126 case QCRYPTO_CIPHER_ALG_SERPENT_256:
127 gcryalg = GCRY_CIPHER_SERPENT256;
130 case QCRYPTO_CIPHER_ALG_TWOFISH_128:
131 gcryalg = GCRY_CIPHER_TWOFISH128;
134 case QCRYPTO_CIPHER_ALG_TWOFISH_256:
135 gcryalg = GCRY_CIPHER_TWOFISH;
139 error_setg(errp, "Unsupported cipher algorithm %s",
140 QCryptoCipherAlgorithm_lookup[alg]);
144 cipher = g_new0(QCryptoCipher, 1);
148 ctx = g_new0(QCryptoCipherGcrypt, 1);
150 err = gcry_cipher_open(&ctx->handle, gcryalg, gcrymode, 0);
152 error_setg(errp, "Cannot initialize cipher: %s",
156 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
157 err = gcry_cipher_open(&ctx->tweakhandle, gcryalg, gcrymode, 0);
159 error_setg(errp, "Cannot initialize cipher: %s",
165 if (cipher->alg == QCRYPTO_CIPHER_ALG_DES_RFB) {
166 /* We're using standard DES cipher from gcrypt, so we need
167 * to munge the key so that the results are the same as the
168 * bizarre RFB variant of DES :-)
170 uint8_t *rfbkey = qcrypto_cipher_munge_des_rfb_key(key, nkey);
171 err = gcry_cipher_setkey(ctx->handle, rfbkey, nkey);
175 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
177 err = gcry_cipher_setkey(ctx->handle, key, nkey);
179 error_setg(errp, "Cannot set key: %s",
183 err = gcry_cipher_setkey(ctx->tweakhandle, key + nkey, nkey);
185 err = gcry_cipher_setkey(ctx->handle, key, nkey);
188 error_setg(errp, "Cannot set key: %s",
192 switch (cipher->alg) {
193 case QCRYPTO_CIPHER_ALG_AES_128:
194 case QCRYPTO_CIPHER_ALG_AES_192:
195 case QCRYPTO_CIPHER_ALG_AES_256:
196 case QCRYPTO_CIPHER_ALG_SERPENT_128:
197 case QCRYPTO_CIPHER_ALG_SERPENT_192:
198 case QCRYPTO_CIPHER_ALG_SERPENT_256:
199 case QCRYPTO_CIPHER_ALG_TWOFISH_128:
200 case QCRYPTO_CIPHER_ALG_TWOFISH_256:
203 case QCRYPTO_CIPHER_ALG_CAST5_128:
207 g_assert_not_reached();
211 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
212 if (ctx->blocksize != XTS_BLOCK_SIZE) {
214 "Cipher block size %zu must equal XTS block size %d",
215 ctx->blocksize, XTS_BLOCK_SIZE);
218 ctx->iv = g_new0(uint8_t, ctx->blocksize);
221 cipher->opaque = ctx;
225 gcry_cipher_close(ctx->handle);
226 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
227 gcry_cipher_close(ctx->tweakhandle);
235 void qcrypto_cipher_free(QCryptoCipher *cipher)
237 QCryptoCipherGcrypt *ctx;
241 ctx = cipher->opaque;
242 gcry_cipher_close(ctx->handle);
243 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
244 gcry_cipher_close(ctx->tweakhandle);
252 static void qcrypto_gcrypt_xts_encrypt(const void *ctx,
258 err = gcry_cipher_encrypt((gcry_cipher_hd_t)ctx, dst, length, src, length);
262 static void qcrypto_gcrypt_xts_decrypt(const void *ctx,
268 err = gcry_cipher_decrypt((gcry_cipher_hd_t)ctx, dst, length, src, length);
272 int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
278 QCryptoCipherGcrypt *ctx = cipher->opaque;
281 if (len % ctx->blocksize) {
282 error_setg(errp, "Length %zu must be a multiple of block size %zu",
283 len, ctx->blocksize);
287 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
288 xts_encrypt(ctx->handle, ctx->tweakhandle,
289 qcrypto_gcrypt_xts_encrypt,
290 qcrypto_gcrypt_xts_decrypt,
291 ctx->iv, len, out, in);
293 err = gcry_cipher_encrypt(ctx->handle,
297 error_setg(errp, "Cannot encrypt data: %s",
307 int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
313 QCryptoCipherGcrypt *ctx = cipher->opaque;
316 if (len % ctx->blocksize) {
317 error_setg(errp, "Length %zu must be a multiple of block size %zu",
318 len, ctx->blocksize);
322 if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
323 xts_decrypt(ctx->handle, ctx->tweakhandle,
324 qcrypto_gcrypt_xts_encrypt,
325 qcrypto_gcrypt_xts_decrypt,
326 ctx->iv, len, out, in);
328 err = gcry_cipher_decrypt(ctx->handle,
332 error_setg(errp, "Cannot decrypt data: %s",
341 int qcrypto_cipher_setiv(QCryptoCipher *cipher,
342 const uint8_t *iv, size_t niv,
345 QCryptoCipherGcrypt *ctx = cipher->opaque;
348 if (niv != ctx->blocksize) {
349 error_setg(errp, "Expected IV size %zu not %zu",
350 ctx->blocksize, niv);
355 memcpy(ctx->iv, iv, niv);
357 if (cipher->mode == QCRYPTO_CIPHER_MODE_CTR) {
358 err = gcry_cipher_setctr(ctx->handle, iv, niv);
360 error_setg(errp, "Cannot set Counter: %s",
365 gcry_cipher_reset(ctx->handle);
366 err = gcry_cipher_setiv(ctx->handle, iv, niv);
368 error_setg(errp, "Cannot set IV: %s",