new file mode 100644
@@ -0,0 +1,325 @@
+/*
+ * QEMU Crypto cipher gnutls algorithms
+ *
+ * Copyright (c) 2021 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "cipherpriv.h"
+
+#include <gnutls/crypto.h>
+
+#if GNUTLS_VERSION_NUMBER >= 0x030608
+#define QEMU_GNUTLS_XTS
+#endif
+
+bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
+ QCryptoCipherMode mode)
+{
+
+ switch (mode) {
+ case QCRYPTO_CIPHER_MODE_ECB:
+ case QCRYPTO_CIPHER_MODE_CBC:
+ switch (alg) {
+ case QCRYPTO_CIPHER_ALG_AES_128:
+ case QCRYPTO_CIPHER_ALG_AES_192:
+ case QCRYPTO_CIPHER_ALG_AES_256:
+ case QCRYPTO_CIPHER_ALG_DES:
+ case QCRYPTO_CIPHER_ALG_3DES:
+ return true;
+ default:
+ return false;
+ }
+#ifdef QEMU_GNUTLS_XTS
+ case QCRYPTO_CIPHER_MODE_XTS:
+ switch (alg) {
+ case QCRYPTO_CIPHER_ALG_AES_128:
+ case QCRYPTO_CIPHER_ALG_AES_256:
+ return true;
+ default:
+ return false;
+ }
+ return true;
+#endif
+ default:
+ return false;
+ }
+}
+
+typedef struct QCryptoCipherGnutls QCryptoCipherGnutls;
+struct QCryptoCipherGnutls {
+ QCryptoCipher base;
+ gnutls_cipher_hd_t handle; /* XTS & CBC mode */
+ gnutls_cipher_algorithm_t galg; /* ECB mode */
+ guint8 *key; /* ECB mode */
+ size_t nkey; /* ECB mode */
+ size_t blocksize;
+};
+
+
+static void
+qcrypto_gnutls_cipher_free(QCryptoCipher *cipher)
+{
+ QCryptoCipherGnutls *ctx = container_of(cipher, QCryptoCipherGnutls, base);
+
+ g_free(ctx->key);
+ if (ctx->handle) {
+ gnutls_cipher_deinit(ctx->handle);
+ }
+ g_free(ctx);
+}
+
+
+static int
+qcrypto_gnutls_cipher_encrypt(QCryptoCipher *cipher,
+ const void *in,
+ void *out,
+ size_t len,
+ Error **errp)
+{
+ QCryptoCipherGnutls *ctx = container_of(cipher, QCryptoCipherGnutls, base);
+ int err;
+
+ if (len % ctx->blocksize) {
+ error_setg(errp, "Length %zu must be a multiple of block size %zu",
+ len, ctx->blocksize);
+ return -1;
+ }
+
+ if (ctx->handle) { /* CBC / XTS mode */
+ err = gnutls_cipher_encrypt2(ctx->handle,
+ in, len,
+ out, len);
+ if (err != 0) {
+ error_setg(errp, "Cannot encrypt data: %s",
+ gnutls_strerror(err));
+ return -1;
+ }
+ } else { /* ECB mode very inefficiently faked with CBC */
+ g_autofree unsigned char *iv = g_new0(unsigned char, ctx->blocksize);
+ while (len) {
+ gnutls_cipher_hd_t handle;
+ gnutls_datum_t gkey = { (unsigned char *)ctx->key, ctx->nkey };
+ int err = gnutls_cipher_init(&handle, ctx->galg, &gkey, NULL);
+ if (err != 0) {
+ error_setg(errp, "Cannot initialize cipher: %s",
+ gnutls_strerror(err));
+ return -1;
+ }
+
+ gnutls_cipher_set_iv(handle, iv, ctx->blocksize);
+
+ err = gnutls_cipher_encrypt2(handle,
+ in, ctx->blocksize,
+ out, ctx->blocksize);
+ if (err != 0) {
+ gnutls_cipher_deinit(handle);
+ error_setg(errp, "Cannot encrypt data: %s",
+ gnutls_strerror(err));
+ return -1;
+ }
+ gnutls_cipher_deinit(handle);
+
+ len -= ctx->blocksize;
+ in += ctx->blocksize;
+ out += ctx->blocksize;
+ }
+ }
+
+ return 0;
+}
+
+
+static int
+qcrypto_gnutls_cipher_decrypt(QCryptoCipher *cipher,
+ const void *in,
+ void *out,
+ size_t len,
+ Error **errp)
+{
+ QCryptoCipherGnutls *ctx = container_of(cipher, QCryptoCipherGnutls, base);
+ int err;
+
+ if (len % ctx->blocksize) {
+ error_setg(errp, "Length %zu must be a multiple of block size %zu",
+ len, ctx->blocksize);
+ return -1;
+ }
+
+ if (ctx->handle) { /* CBC / XTS mode */
+ err = gnutls_cipher_decrypt2(ctx->handle,
+ in, len,
+ out, len);
+
+ if (err != 0) {
+ error_setg(errp, "Cannot decrypt data: %s",
+ gnutls_strerror(err));
+ return -1;
+ }
+ } else { /* ECB mode very inefficiently faked with CBC */
+ g_autofree unsigned char *iv = g_new0(unsigned char, ctx->blocksize);
+ while (len) {
+ gnutls_cipher_hd_t handle;
+ gnutls_datum_t gkey = { (unsigned char *)ctx->key, ctx->nkey };
+ int err = gnutls_cipher_init(&handle, ctx->galg, &gkey, NULL);
+ if (err != 0) {
+ error_setg(errp, "Cannot initialize cipher: %s",
+ gnutls_strerror(err));
+ return -1;
+ }
+
+ gnutls_cipher_set_iv(handle, iv, ctx->blocksize);
+
+ err = gnutls_cipher_decrypt2(handle,
+ in, ctx->blocksize,
+ out, ctx->blocksize);
+ if (err != 0) {
+ gnutls_cipher_deinit(handle);
+ error_setg(errp, "Cannot encrypt data: %s",
+ gnutls_strerror(err));
+ return -1;
+ }
+ gnutls_cipher_deinit(handle);
+
+ len -= ctx->blocksize;
+ in += ctx->blocksize;
+ out += ctx->blocksize;
+ }
+ }
+
+ return 0;
+}
+
+static int
+qcrypto_gnutls_cipher_setiv(QCryptoCipher *cipher,
+ const uint8_t *iv, size_t niv,
+ Error **errp)
+{
+ QCryptoCipherGnutls *ctx = container_of(cipher, QCryptoCipherGnutls, base);
+
+ if (niv != ctx->blocksize) {
+ error_setg(errp, "Expected IV size %zu not %zu",
+ ctx->blocksize, niv);
+ return -1;
+ }
+
+ gnutls_cipher_set_iv(ctx->handle, (unsigned char *)iv, niv);
+
+ return 0;
+}
+
+
+static struct QCryptoCipherDriver gnutls_driver = {
+ .cipher_encrypt = qcrypto_gnutls_cipher_encrypt,
+ .cipher_decrypt = qcrypto_gnutls_cipher_decrypt,
+ .cipher_setiv = qcrypto_gnutls_cipher_setiv,
+ .cipher_free = qcrypto_gnutls_cipher_free,
+};
+
+static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
+ QCryptoCipherMode mode,
+ const uint8_t *key,
+ size_t nkey,
+ Error **errp)
+{
+ QCryptoCipherGnutls *ctx;
+ gnutls_datum_t gkey = { (unsigned char *)key, nkey };
+ gnutls_cipher_algorithm_t galg = GNUTLS_CIPHER_UNKNOWN;
+ int err;
+
+ switch (mode) {
+#ifdef QEMU_GNUTLS_XTS
+ case QCRYPTO_CIPHER_MODE_XTS:
+ switch (alg) {
+ case QCRYPTO_CIPHER_ALG_AES_128:
+ galg = GNUTLS_CIPHER_AES_128_XTS;
+ break;
+ case QCRYPTO_CIPHER_ALG_AES_256:
+ galg = GNUTLS_CIPHER_AES_256_XTS;
+ break;
+ default:
+ break;
+ }
+ break;
+#endif
+
+ case QCRYPTO_CIPHER_MODE_ECB:
+ case QCRYPTO_CIPHER_MODE_CBC:
+ switch (alg) {
+ case QCRYPTO_CIPHER_ALG_AES_128:
+ galg = GNUTLS_CIPHER_AES_128_CBC;
+ break;
+ case QCRYPTO_CIPHER_ALG_AES_192:
+ galg = GNUTLS_CIPHER_AES_192_CBC;
+ break;
+ case QCRYPTO_CIPHER_ALG_AES_256:
+ galg = GNUTLS_CIPHER_AES_256_CBC;
+ break;
+ case QCRYPTO_CIPHER_ALG_DES:
+ galg = GNUTLS_CIPHER_DES_CBC;
+ break;
+ case QCRYPTO_CIPHER_ALG_3DES:
+ galg = GNUTLS_CIPHER_3DES_CBC;
+ break;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+
+ if (galg == GNUTLS_CIPHER_UNKNOWN) {
+ error_setg(errp, "Unsupported cipher algorithm %s with %s mode",
+ QCryptoCipherAlgorithm_str(alg),
+ QCryptoCipherMode_str(mode));
+ return NULL;
+ }
+
+ if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
+ return NULL;
+ }
+
+ ctx = g_new0(QCryptoCipherGnutls, 1);
+ ctx->base.driver = &gnutls_driver;
+
+ if (mode == QCRYPTO_CIPHER_MODE_ECB) {
+ ctx->key = g_new0(guint8, nkey);
+ memcpy(ctx->key, key, nkey);
+ ctx->nkey = nkey;
+ ctx->galg = galg;
+ } else {
+ err = gnutls_cipher_init(&ctx->handle, galg, &gkey, NULL);
+ if (err != 0) {
+ error_setg(errp, "Cannot initialize cipher: %s",
+ gnutls_strerror(err));
+ goto error;
+ }
+ }
+
+ if (alg == QCRYPTO_CIPHER_ALG_DES ||
+ alg == QCRYPTO_CIPHER_ALG_3DES)
+ ctx->blocksize = 8;
+ else
+ ctx->blocksize = 16;
+
+ return &ctx->base;
+
+ error:
+ qcrypto_gnutls_cipher_free(&ctx->base);
+ return NULL;
+}
@@ -136,6 +136,8 @@ qcrypto_cipher_validate_key_length(QCryptoCipherAlgorithm alg,
#include "cipher-gcrypt.c.inc"
#elif defined CONFIG_NETTLE
#include "cipher-nettle.c.inc"
+#elif defined CONFIG_GNUTLS_CRYPTO
+#include "cipher-gnutls.c.inc"
#else
#include "cipher-builtin.c.inc"
#endif
Add an implementation of the QEMU cipher APIs to the gnutls crypto backend. XTS support is only available for gnutls version >= 3.6.8. Since ECB mode is not exposed by gnutls APIs, we can't use the private XTS code for compatibility. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- crypto/cipher-gnutls.c.inc | 325 +++++++++++++++++++++++++++++++++++++ crypto/cipher.c | 2 + 2 files changed, 327 insertions(+) create mode 100644 crypto/cipher-gnutls.c.inc