diff options
Diffstat (limited to 'qemu/block/crypto.c')
| -rw-r--r-- | qemu/block/crypto.c | 586 |
1 files changed, 586 insertions, 0 deletions
diff --git a/qemu/block/crypto.c b/qemu/block/crypto.c new file mode 100644 index 000000000..1903e84fb --- /dev/null +++ b/qemu/block/crypto.c @@ -0,0 +1,586 @@ +/* + * 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); |