--- /dev/null
+/*
+ * QEMU block full disk encryption
+ *
+ * Copyright (c) 2015-2016 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 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 "block/block_int.h"
+#include "sysemu/block-backend.h"
+#include "crypto/block.h"
+#include "qapi/opts-visitor.h"
+#include "qapi-visit.h"
+#include "qapi/error.h"
+
+#define BLOCK_CRYPTO_OPT_LUKS_KEY_SECRET "key-secret"
+#define BLOCK_CRYPTO_OPT_LUKS_CIPHER_ALG "cipher-alg"
+#define BLOCK_CRYPTO_OPT_LUKS_CIPHER_MODE "cipher-mode"
+#define BLOCK_CRYPTO_OPT_LUKS_IVGEN_ALG "ivgen-alg"
+#define BLOCK_CRYPTO_OPT_LUKS_IVGEN_HASH_ALG "ivgen-hash-alg"
+#define BLOCK_CRYPTO_OPT_LUKS_HASH_ALG "hash-alg"
+
+typedef struct BlockCrypto BlockCrypto;
+
+struct BlockCrypto {
+ QCryptoBlock *block;
+};
+
+
+static int block_crypto_probe_generic(QCryptoBlockFormat format,
+ const uint8_t *buf,
+ int buf_size,
+ const char *filename)
+{
+ if (qcrypto_block_has_format(format, buf, buf_size)) {
+ return 100;
+ } else {
+ return 0;
+ }
+}
+
+
+static ssize_t block_crypto_read_func(QCryptoBlock *block,
+ size_t offset,
+ uint8_t *buf,
+ size_t buflen,
+ Error **errp,
+ void *opaque)
+{
+ BlockDriverState *bs = opaque;
+ ssize_t ret;
+
+ ret = bdrv_pread(bs->file->bs, offset, buf, buflen);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not read encryption header");
+ return ret;
+ }
+ return ret;
+}
+
+
+struct BlockCryptoCreateData {
+ const char *filename;
+ QemuOpts *opts;
+ BlockBackend *blk;
+ uint64_t size;
+};
+
+
+static ssize_t block_crypto_write_func(QCryptoBlock *block,
+ size_t offset,
+ const uint8_t *buf,
+ size_t buflen,
+ Error **errp,
+ void *opaque)
+{
+ struct BlockCryptoCreateData *data = opaque;
+ ssize_t ret;
+
+ ret = blk_pwrite(data->blk, offset, buf, buflen);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not write encryption header");
+ return ret;
+ }
+ return ret;
+}
+
+
+static ssize_t block_crypto_init_func(QCryptoBlock *block,
+ size_t headerlen,
+ Error **errp,
+ void *opaque)
+{
+ struct BlockCryptoCreateData *data = opaque;
+ int ret;
+
+ /* User provided size should reflect amount of space made
+ * available to the guest, so we must take account of that
+ * which will be used by the crypto header
+ */
+ data->size += headerlen;
+
+ qemu_opt_set_number(data->opts, BLOCK_OPT_SIZE, data->size, &error_abort);
+ ret = bdrv_create_file(data->filename, data->opts, errp);
+ if (ret < 0) {
+ return -1;
+ }
+
+ data->blk = blk_new_open(data->filename, NULL, NULL,
+ BDRV_O_RDWR | BDRV_O_PROTOCOL, errp);
+ if (!data->blk) {
+ return -1;
+ }
+
+ return 0;
+}
+
+
+static QemuOptsList block_crypto_runtime_opts_luks = {
+ .name = "crypto",
+ .head = QTAILQ_HEAD_INITIALIZER(block_crypto_runtime_opts_luks.head),
+ .desc = {
+ {
+ .name = BLOCK_CRYPTO_OPT_LUKS_KEY_SECRET,
+ .type = QEMU_OPT_STRING,
+ .help = "ID of the secret that provides the encryption key",
+ },
+ { /* end of list */ }
+ },
+};
+
+
+static QemuOptsList block_crypto_create_opts_luks = {
+ .name = "crypto",
+ .head = QTAILQ_HEAD_INITIALIZER(block_crypto_create_opts_luks.head),
+ .desc = {
+ {
+ .name = BLOCK_OPT_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Virtual disk size"
+ },
+ {
+ .name = BLOCK_CRYPTO_OPT_LUKS_KEY_SECRET,
+ .type = QEMU_OPT_STRING,
+ .help = "ID of the secret that provides the encryption key",
+ },
+ {
+ .name = BLOCK_CRYPTO_OPT_LUKS_CIPHER_ALG,
+ .type = QEMU_OPT_STRING,
+ .help = "Name of encryption cipher algorithm",
+ },
+ {
+ .name = BLOCK_CRYPTO_OPT_LUKS_CIPHER_MODE,
+ .type = QEMU_OPT_STRING,
+ .help = "Name of encryption cipher mode",
+ },
+ {
+ .name = BLOCK_CRYPTO_OPT_LUKS_IVGEN_ALG,
+ .type = QEMU_OPT_STRING,
+ .help = "Name of IV generator algorithm",
+ },
+ {
+ .name = BLOCK_CRYPTO_OPT_LUKS_IVGEN_HASH_ALG,
+ .type = QEMU_OPT_STRING,
+ .help = "Name of IV generator hash algorithm",
+ },
+ {
+ .name = BLOCK_CRYPTO_OPT_LUKS_HASH_ALG,
+ .type = QEMU_OPT_STRING,
+ .help = "Name of encryption hash algorithm",
+ },
+ { /* end of list */ }
+ },
+};
+
+
+static QCryptoBlockOpenOptions *
+block_crypto_open_opts_init(QCryptoBlockFormat format,
+ QemuOpts *opts,
+ Error **errp)
+{
+ OptsVisitor *ov;
+ QCryptoBlockOpenOptions *ret = NULL;
+ Error *local_err = NULL;
+ Error *end_err = NULL;
+
+ ret = g_new0(QCryptoBlockOpenOptions, 1);
+ ret->format = format;
+
+ ov = opts_visitor_new(opts);
+
+ visit_start_struct(opts_get_visitor(ov),
+ NULL, NULL, 0, &local_err);
+ if (local_err) {
+ goto out;
+ }
+
+ switch (format) {
+ case Q_CRYPTO_BLOCK_FORMAT_LUKS:
+ visit_type_QCryptoBlockOptionsLUKS_members(
+ opts_get_visitor(ov), &ret->u.luks, &local_err);
+ break;
+
+ default:
+ error_setg(&local_err, "Unsupported block format %d", format);
+ break;
+ }
+
+ visit_end_struct(opts_get_visitor(ov), &end_err);
+ error_propagate(&local_err, end_err);
+
+ out:
+ if (local_err) {
+ error_propagate(errp, local_err);
+ qapi_free_QCryptoBlockOpenOptions(ret);
+ ret = NULL;
+ }
+ opts_visitor_cleanup(ov);
+ return ret;
+}
+
+
+static QCryptoBlockCreateOptions *
+block_crypto_create_opts_init(QCryptoBlockFormat format,
+ QemuOpts *opts,
+ Error **errp)
+{
+ OptsVisitor *ov;
+ QCryptoBlockCreateOptions *ret = NULL;
+ Error *local_err = NULL;
+ Error *end_err = NULL;
+
+ ret = g_new0(QCryptoBlockCreateOptions, 1);
+ ret->format = format;
+
+ ov = opts_visitor_new(opts);
+
+ visit_start_struct(opts_get_visitor(ov),
+ NULL, NULL, 0, &local_err);
+ if (local_err) {
+ goto out;
+ }
+
+ switch (format) {
+ case Q_CRYPTO_BLOCK_FORMAT_LUKS:
+ visit_type_QCryptoBlockCreateOptionsLUKS_members(
+ opts_get_visitor(ov), &ret->u.luks, &local_err);
+ break;
+
+ default:
+ error_setg(&local_err, "Unsupported block format %d", format);
+ break;
+ }
+
+ visit_end_struct(opts_get_visitor(ov), &end_err);
+ error_propagate(&local_err, end_err);
+
+ out:
+ if (local_err) {
+ error_propagate(errp, local_err);
+ qapi_free_QCryptoBlockCreateOptions(ret);
+ ret = NULL;
+ }
+ opts_visitor_cleanup(ov);
+ return ret;
+}
+
+
+static int block_crypto_open_generic(QCryptoBlockFormat format,
+ QemuOptsList *opts_spec,
+ BlockDriverState *bs,
+ QDict *options,
+ int flags,
+ Error **errp)
+{
+ BlockCrypto *crypto = bs->opaque;
+ QemuOpts *opts = NULL;
+ Error *local_err = NULL;
+ int ret = -EINVAL;
+ QCryptoBlockOpenOptions *open_opts = NULL;
+ unsigned int cflags = 0;
+
+ opts = qemu_opts_create(opts_spec, NULL, 0, &error_abort);
+ qemu_opts_absorb_qdict(opts, options, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ goto cleanup;
+ }
+
+ open_opts = block_crypto_open_opts_init(format, opts, errp);
+ if (!open_opts) {
+ goto cleanup;
+ }
+
+ if (flags & BDRV_O_NO_IO) {
+ cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
+ }
+ crypto->block = qcrypto_block_open(open_opts,
+ block_crypto_read_func,
+ bs,
+ cflags,
+ errp);
+
+ if (!crypto->block) {
+ ret = -EIO;
+ goto cleanup;
+ }
+
+ bs->encrypted = 1;
+ bs->valid_key = 1;
+
+ ret = 0;
+ cleanup:
+ qapi_free_QCryptoBlockOpenOptions(open_opts);
+ return ret;
+}
+
+
+static int block_crypto_create_generic(QCryptoBlockFormat format,
+ const char *filename,
+ QemuOpts *opts,
+ Error **errp)
+{
+ int ret = -EINVAL;
+ QCryptoBlockCreateOptions *create_opts = NULL;
+ QCryptoBlock *crypto = NULL;
+ struct BlockCryptoCreateData data = {
+ .size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
+ BDRV_SECTOR_SIZE),
+ .opts = opts,
+ .filename = filename,
+ };
+
+ create_opts = block_crypto_create_opts_init(format, opts, errp);
+ if (!create_opts) {
+ return -1;
+ }
+
+ crypto = qcrypto_block_create(create_opts,
+ block_crypto_init_func,
+ block_crypto_write_func,
+ &data,
+ errp);
+
+ if (!crypto) {
+ ret = -EIO;
+ goto cleanup;
+ }
+
+ ret = 0;
+ cleanup:
+ qcrypto_block_free(crypto);
+ blk_unref(data.blk);
+ qapi_free_QCryptoBlockCreateOptions(create_opts);
+ return ret;
+}
+
+static int block_crypto_truncate(BlockDriverState *bs, int64_t offset)
+{
+ BlockCrypto *crypto = bs->opaque;
+ size_t payload_offset =
+ qcrypto_block_get_payload_offset(crypto->block);
+
+ offset += payload_offset;
+
+ return bdrv_truncate(bs->file->bs, offset);
+}
+
+static void block_crypto_close(BlockDriverState *bs)
+{
+ BlockCrypto *crypto = bs->opaque;
+ qcrypto_block_free(crypto->block);
+}
+
+
+#define BLOCK_CRYPTO_MAX_SECTORS 32
+
+static coroutine_fn int
+block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num,
+ int remaining_sectors, QEMUIOVector *qiov)
+{
+ BlockCrypto *crypto = bs->opaque;
+ int cur_nr_sectors; /* number of sectors in current iteration */
+ uint64_t bytes_done = 0;
+ uint8_t *cipher_data = NULL;
+ QEMUIOVector hd_qiov;
+ int ret = 0;
+ size_t payload_offset =
+ qcrypto_block_get_payload_offset(crypto->block) / 512;
+
+ qemu_iovec_init(&hd_qiov, qiov->niov);
+
+ /* Bounce buffer so we have a linear mem region for
+ * entire sector. XXX optimize so we avoid bounce
+ * buffer in case that qiov->niov == 1
+ */
+ cipher_data =
+ qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_SECTORS * 512,
+ qiov->size));
+ if (cipher_data == NULL) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+
+ while (remaining_sectors) {
+ cur_nr_sectors = remaining_sectors;
+
+ if (cur_nr_sectors > BLOCK_CRYPTO_MAX_SECTORS) {
+ cur_nr_sectors = BLOCK_CRYPTO_MAX_SECTORS;
+ }
+
+ qemu_iovec_reset(&hd_qiov);
+ qemu_iovec_add(&hd_qiov, cipher_data, cur_nr_sectors * 512);
+
+ ret = bdrv_co_readv(bs->file->bs,
+ payload_offset + sector_num,
+ cur_nr_sectors, &hd_qiov);
+ if (ret < 0) {
+ goto cleanup;
+ }
+
+ if (qcrypto_block_decrypt(crypto->block,
+ sector_num,
+ cipher_data, cur_nr_sectors * 512,
+ NULL) < 0) {
+ ret = -EIO;
+ goto cleanup;
+ }
+
+ qemu_iovec_from_buf(qiov, bytes_done,
+ cipher_data, cur_nr_sectors * 512);
+
+ remaining_sectors -= cur_nr_sectors;
+ sector_num += cur_nr_sectors;
+ bytes_done += cur_nr_sectors * 512;
+ }
+
+ cleanup:
+ qemu_iovec_destroy(&hd_qiov);
+ qemu_vfree(cipher_data);
+
+ return ret;
+}
+
+
+static coroutine_fn int
+block_crypto_co_writev(BlockDriverState *bs, int64_t sector_num,
+ int remaining_sectors, QEMUIOVector *qiov)
+{
+ BlockCrypto *crypto = bs->opaque;
+ int cur_nr_sectors; /* number of sectors in current iteration */
+ uint64_t bytes_done = 0;
+ uint8_t *cipher_data = NULL;
+ QEMUIOVector hd_qiov;
+ int ret = 0;
+ size_t payload_offset =
+ qcrypto_block_get_payload_offset(crypto->block) / 512;
+
+ qemu_iovec_init(&hd_qiov, qiov->niov);
+
+ /* Bounce buffer so we have a linear mem region for
+ * entire sector. XXX optimize so we avoid bounce
+ * buffer in case that qiov->niov == 1
+ */
+ cipher_data =
+ qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_SECTORS * 512,
+ qiov->size));
+ if (cipher_data == NULL) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+
+ while (remaining_sectors) {
+ cur_nr_sectors = remaining_sectors;
+
+ if (cur_nr_sectors > BLOCK_CRYPTO_MAX_SECTORS) {
+ cur_nr_sectors = BLOCK_CRYPTO_MAX_SECTORS;
+ }
+
+ qemu_iovec_to_buf(qiov, bytes_done,
+ cipher_data, cur_nr_sectors * 512);
+
+ if (qcrypto_block_encrypt(crypto->block,
+ sector_num,
+ cipher_data, cur_nr_sectors * 512,
+ NULL) < 0) {
+ ret = -EIO;
+ goto cleanup;
+ }
+
+ qemu_iovec_reset(&hd_qiov);
+ qemu_iovec_add(&hd_qiov, cipher_data, cur_nr_sectors * 512);
+
+ ret = bdrv_co_writev(bs->file->bs,
+ payload_offset + sector_num,
+ cur_nr_sectors, &hd_qiov);
+ if (ret < 0) {
+ goto cleanup;
+ }
+
+ remaining_sectors -= cur_nr_sectors;
+ sector_num += cur_nr_sectors;
+ bytes_done += cur_nr_sectors * 512;
+ }
+
+ cleanup:
+ qemu_iovec_destroy(&hd_qiov);
+ qemu_vfree(cipher_data);
+
+ return ret;
+}
+
+
+static int64_t block_crypto_getlength(BlockDriverState *bs)
+{
+ BlockCrypto *crypto = bs->opaque;
+ int64_t len = bdrv_getlength(bs->file->bs);
+
+ ssize_t offset = qcrypto_block_get_payload_offset(crypto->block);
+
+ len -= offset;
+
+ return len;
+}
+
+
+static int block_crypto_probe_luks(const uint8_t *buf,
+ int buf_size,
+ const char *filename) {
+ return block_crypto_probe_generic(Q_CRYPTO_BLOCK_FORMAT_LUKS,
+ buf, buf_size, filename);
+}
+
+static int block_crypto_open_luks(BlockDriverState *bs,
+ QDict *options,
+ int flags,
+ Error **errp)
+{
+ return block_crypto_open_generic(Q_CRYPTO_BLOCK_FORMAT_LUKS,
+ &block_crypto_runtime_opts_luks,
+ bs, options, flags, errp);
+}
+
+static int block_crypto_create_luks(const char *filename,
+ QemuOpts *opts,
+ Error **errp)
+{
+ return block_crypto_create_generic(Q_CRYPTO_BLOCK_FORMAT_LUKS,
+ filename, opts, errp);
+}
+
+BlockDriver bdrv_crypto_luks = {
+ .format_name = "luks",
+ .instance_size = sizeof(BlockCrypto),
+ .bdrv_probe = block_crypto_probe_luks,
+ .bdrv_open = block_crypto_open_luks,
+ .bdrv_close = block_crypto_close,
+ .bdrv_create = block_crypto_create_luks,
+ .bdrv_truncate = block_crypto_truncate,
+ .create_opts = &block_crypto_create_opts_luks,
+
+ .bdrv_co_readv = block_crypto_co_readv,
+ .bdrv_co_writev = block_crypto_co_writev,
+ .bdrv_getlength = block_crypto_getlength,
+};
+
+static void block_crypto_init(void)
+{
+ bdrv_register(&bdrv_crypto_luks);
+}
+
+block_init(block_crypto_init);
Code Review / kvmfornfv.git / blobdiff