#define QCOW2_EXT_MAGIC_END 0
#define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
#define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
+#define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77
static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename)
{
}
+static ssize_t qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset,
+ uint8_t *buf, size_t buflen,
+ void *opaque, Error **errp)
+{
+ BlockDriverState *bs = opaque;
+ BDRVQcow2State *s = bs->opaque;
+ ssize_t ret;
+
+ if ((offset + buflen) > s->crypto_header.length) {
+ error_setg(errp, "Request for data outside of extension header");
+ return -1;
+ }
+
+ ret = bdrv_pread(bs->file,
+ s->crypto_header.offset + offset, buf, buflen);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not read encryption header");
+ return -1;
+ }
+ return ret;
+}
+
+
+static ssize_t qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen,
+ void *opaque, Error **errp)
+{
+ BlockDriverState *bs = opaque;
+ BDRVQcow2State *s = bs->opaque;
+ int64_t ret;
+ int64_t clusterlen;
+
+ ret = qcow2_alloc_clusters(bs, headerlen);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret,
+ "Cannot allocate cluster for LUKS header size %zu",
+ headerlen);
+ return -1;
+ }
+
+ s->crypto_header.length = headerlen;
+ s->crypto_header.offset = ret;
+
+ /* Zero fill remaining space in cluster so it has predictable
+ * content in case of future spec changes */
+ clusterlen = size_to_clusters(s, headerlen) * s->cluster_size;
+ ret = bdrv_pwrite_zeroes(bs->file,
+ ret + headerlen,
+ clusterlen - headerlen, 0);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not zero fill encryption header");
+ return -1;
+ }
+
+ return ret;
+}
+
+
+static ssize_t qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset,
+ const uint8_t *buf, size_t buflen,
+ void *opaque, Error **errp)
+{
+ BlockDriverState *bs = opaque;
+ BDRVQcow2State *s = bs->opaque;
+ ssize_t ret;
+
+ if ((offset + buflen) > s->crypto_header.length) {
+ error_setg(errp, "Request for data outside of extension header");
+ return -1;
+ }
+
+ ret = bdrv_pwrite(bs->file,
+ s->crypto_header.offset + offset, buf, buflen);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not read encryption header");
+ return -1;
+ }
+ return ret;
+}
+
+
/*
* read qcow2 extension and fill bs
* start reading from start_offset
*/
static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset,
uint64_t end_offset, void **p_feature_table,
- Error **errp)
+ int flags, Error **errp)
{
BDRVQcow2State *s = bs->opaque;
QCowExtension ext;
}
break;
+ case QCOW2_EXT_MAGIC_CRYPTO_HEADER: {
+ unsigned int cflags = 0;
+ if (s->crypt_method_header != QCOW_CRYPT_LUKS) {
+ error_setg(errp, "CRYPTO header extension only "
+ "expected with LUKS encryption method");
+ return -EINVAL;
+ }
+ if (ext.len != sizeof(Qcow2CryptoHeaderExtension)) {
+ error_setg(errp, "CRYPTO header extension size %u, "
+ "but expected size %zu", ext.len,
+ sizeof(Qcow2CryptoHeaderExtension));
+ return -EINVAL;
+ }
+
+ ret = bdrv_pread(bs->file, offset, &s->crypto_header, ext.len);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret,
+ "Unable to read CRYPTO header extension");
+ return ret;
+ }
+ be64_to_cpus(&s->crypto_header.offset);
+ be64_to_cpus(&s->crypto_header.length);
+
+ if ((s->crypto_header.offset % s->cluster_size) != 0) {
+ error_setg(errp, "Encryption header offset '%" PRIu64 "' is "
+ "not a multiple of cluster size '%u'",
+ s->crypto_header.offset, s->cluster_size);
+ return -EINVAL;
+ }
+
+ if (flags & BDRV_O_NO_IO) {
+ cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
+ }
+ s->crypto = qcrypto_block_open(s->crypto_opts,
+ qcow2_crypto_hdr_read_func,
+ bs, cflags, errp);
+ if (!s->crypto) {
+ return -EINVAL;
+ }
+ } break;
+
default:
/* unknown magic - save it in case we need to rewrite the header */
{
.type = QEMU_OPT_NUMBER,
.help = "Clean unused cache entries after this time (in seconds)",
},
- BLOCK_CRYPTO_OPT_DEF_QCOW_KEY_SECRET("encrypt."),
+ BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.",
+ "ID of secret providing qcow2 AES key or LUKS passphrase"),
{ /* end of list */ }
},
};
Q_CRYPTO_BLOCK_FORMAT_QCOW, encryptopts, errp);
break;
+ case QCOW_CRYPT_LUKS:
+ if (encryptfmt && !g_str_equal(encryptfmt, "luks")) {
+ error_setg(errp,
+ "Header reported 'luks' encryption format but "
+ "options specify '%s'", encryptfmt);
+ ret = -EINVAL;
+ goto fail;
+ }
+ qdict_del(encryptopts, "format");
+ r->crypto_opts = block_crypto_open_opts_init(
+ Q_CRYPTO_BLOCK_FORMAT_LUKS, encryptopts, errp);
+ break;
+
default:
error_setg(errp, "Unsupported encryption method %d",
s->crypt_method_header);
if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) {
void *feature_table = NULL;
qcow2_read_extensions(bs, header.header_length, ext_end,
- &feature_table, NULL);
+ &feature_table, flags, NULL);
report_unsupported_feature(errp, feature_table,
s->incompatible_features &
~QCOW2_INCOMPAT_MASK);
s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1);
s->refcount_max += s->refcount_max - 1;
- if (header.crypt_method > QCOW_CRYPT_AES) {
- error_setg(errp, "Unsupported encryption method: %" PRIu32,
- header.crypt_method);
- ret = -EINVAL;
- goto fail;
- }
s->crypt_method_header = header.crypt_method;
if (s->crypt_method_header) {
if (bdrv_uses_whitelist() &&
goto fail;
}
+ if (s->crypt_method_header == QCOW_CRYPT_AES) {
+ s->crypt_physical_offset = false;
+ } else {
+ /* Assuming LUKS and any future crypt methods we
+ * add will all use physical offsets, due to the
+ * fact that the alternative is insecure... */
+ s->crypt_physical_offset = true;
+ }
+
bs->encrypted = true;
bs->valid_key = true;
}
/* read qcow2 extensions */
if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL,
- &local_err)) {
+ flags, &local_err)) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto fail;
}
- if (s->crypt_method_header == QCOW_CRYPT_AES) {
- unsigned int cflags = 0;
- if (flags & BDRV_O_NO_IO) {
- cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
- }
- s->crypto = qcrypto_block_open(s->crypto_opts, NULL, NULL,
- cflags, errp);
- if (!s->crypto) {
+ /* qcow2_read_extension may have set up the crypto context
+ * if the crypt method needs a header region, some methods
+ * don't need header extensions, so must check here
+ */
+ if (s->crypt_method_header && !s->crypto) {
+ if (s->crypt_method_header == QCOW_CRYPT_AES) {
+ unsigned int cflags = 0;
+ if (flags & BDRV_O_NO_IO) {
+ cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
+ }
+ s->crypto = qcrypto_block_open(s->crypto_opts, NULL, NULL,
+ cflags, errp);
+ if (!s->crypto) {
+ ret = -EINVAL;
+ goto fail;
+ }
+ } else if (!(flags & BDRV_O_NO_IO)) {
+ error_setg(errp, "Missing CRYPTO header for crypt method %d",
+ s->crypt_method_header);
ret = -EINVAL;
goto fail;
}
assert((cur_bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
Error *err = NULL;
if (qcrypto_block_decrypt(s->crypto,
- offset >> BDRV_SECTOR_BITS,
+ (s->crypt_physical_offset ?
+ cluster_offset + offset_in_cluster :
+ offset) >> BDRV_SECTOR_BITS,
cluster_data,
cur_bytes,
&err) < 0) {
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size);
- if (qcrypto_block_encrypt(s->crypto, offset >> BDRV_SECTOR_BITS,
+ if (qcrypto_block_encrypt(s->crypto,
+ (s->crypt_physical_offset ?
+ cluster_offset + offset_in_cluster :
+ offset) >> BDRV_SECTOR_BITS,
cluster_data,
cur_bytes, &err) < 0) {
error_free(err);
buflen -= ret;
}
+ /* Full disk encryption header pointer extension */
+ if (s->crypto_header.offset != 0) {
+ cpu_to_be64s(&s->crypto_header.offset);
+ cpu_to_be64s(&s->crypto_header.length);
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER,
+ &s->crypto_header, sizeof(s->crypto_header),
+ buflen);
+ be64_to_cpus(&s->crypto_header.offset);
+ be64_to_cpus(&s->crypto_header.length);
+ if (ret < 0) {
+ goto fail;
+ }
+ buf += ret;
+ buflen -= ret;
+ }
+
/* Feature table */
if (s->qcow_version >= 3) {
Qcow2Feature features[] = {
return qcow2_update_header(bs);
}
+static int qcow2_crypt_method_from_format(const char *encryptfmt)
+{
+ if (g_str_equal(encryptfmt, "luks")) {
+ return QCOW_CRYPT_LUKS;
+ } else if (g_str_equal(encryptfmt, "aes")) {
+ return QCOW_CRYPT_AES;
+ } else {
+ return -EINVAL;
+ }
+}
static int qcow2_set_up_encryption(BlockDriverState *bs, const char *encryptfmt,
QemuOpts *opts, Error **errp)
QCryptoBlock *crypto = NULL;
int ret = -EINVAL;
QDict *options, *encryptopts;
+ int fmt;
options = qemu_opts_to_qdict(opts, NULL);
qdict_extract_subqdict(options, &encryptopts, "encrypt.");
QDECREF(options);
- if (!g_str_equal(encryptfmt, "aes")) {
- error_setg(errp, "Unknown encryption format '%s', expected 'aes'",
- encryptfmt);
- ret = -EINVAL;
- goto out;
+ fmt = qcow2_crypt_method_from_format(encryptfmt);
+
+ switch (fmt) {
+ case QCOW_CRYPT_LUKS:
+ cryptoopts = block_crypto_create_opts_init(
+ Q_CRYPTO_BLOCK_FORMAT_LUKS, encryptopts, errp);
+ break;
+ case QCOW_CRYPT_AES:
+ cryptoopts = block_crypto_create_opts_init(
+ Q_CRYPTO_BLOCK_FORMAT_QCOW, encryptopts, errp);
+ break;
+ default:
+ error_setg(errp, "Unknown encryption format '%s'", encryptfmt);
+ break;
}
- cryptoopts = block_crypto_create_opts_init(
- Q_CRYPTO_BLOCK_FORMAT_QCOW, encryptopts, errp);
if (!cryptoopts) {
ret = -EINVAL;
goto out;
}
- s->crypt_method_header = QCOW_CRYPT_AES;
+ s->crypt_method_header = fmt;
crypto = qcrypto_block_create(cryptoopts,
- NULL, NULL,
+ qcow2_crypto_hdr_init_func,
+ qcow2_crypto_hdr_write_func,
bs, errp);
if (!crypto) {
ret = -EINVAL;
const char *compat = NULL;
uint64_t cluster_size = s->cluster_size;
bool encrypt;
+ int encformat;
int refcount_bits = s->refcount_bits;
Error *local_err = NULL;
int ret;
error_report("Changing the encryption flag is not supported");
return -ENOTSUP;
}
+ } else if (!strcmp(desc->name, BLOCK_OPT_ENCRYPT_FORMAT)) {
+ encformat = qcow2_crypt_method_from_format(
+ qemu_opt_get(opts, BLOCK_OPT_ENCRYPT_FORMAT));
+
+ if (encformat != s->crypt_method_header) {
+ error_report("Changing the encryption format is not supported");
+ return -ENOTSUP;
+ }
} else if (!strcmp(desc->name, BLOCK_OPT_CLUSTER_SIZE)) {
cluster_size = qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE,
cluster_size);
{
.name = BLOCK_OPT_ENCRYPT_FORMAT,
.type = QEMU_OPT_STRING,
- .help = "Encrypt the image, format choices: 'aes'",
+ .help = "Encrypt the image, format choices: 'aes', 'luks'",
},
- BLOCK_CRYPTO_OPT_DEF_QCOW_KEY_SECRET("encrypt."),
+ BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.",
+ "ID of secret providing qcow AES key or LUKS passphrase"),
+ BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."),
+ BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."),
+ BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."),
+ BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."),
+ BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."),
+ BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."),
{
.name = BLOCK_OPT_CLUSTER_SIZE,
.type = QEMU_OPT_SIZE,
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