[libvirt PATCH 2/2] storage: add support for qcow2 LUKS encryption
Daniel P. Berrangé
berrange at redhat.com
Wed Sep 16 17:04:52 UTC 2020
The storage driver was wired up to support creating raw volumes in LUKS
format, but was never adapted to support LUKS-in-qcow2. This is trivial
as it merely requires the encryption properties to be prefixed with
the "encrypt." prefix, and "encrypt.format=luks" when creating the
volume.
Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
---
src/storage/storage_util.c | 70 +++++++++++++++++++++++++++++---------
src/util/virqemu.c | 23 +++++++++----
src/util/virqemu.h | 1 +
3 files changed, 72 insertions(+), 22 deletions(-)
diff --git a/src/storage/storage_util.c b/src/storage/storage_util.c
index cf82ea0a87..e5e4fe428f 100644
--- a/src/storage/storage_util.c
+++ b/src/storage/storage_util.c
@@ -707,7 +707,7 @@ storageBackendCreateQemuImgOpts(virStorageEncryptionInfoDefPtr encinfo,
virStorageFileFormatTypeToString(info->backingFormat));
if (encinfo)
- virQEMUBuildQemuImgKeySecretOpts(&buf, encinfo, info->secretAlias);
+ virQEMUBuildQemuImgKeySecretOpts(&buf, info->format, encinfo, info->secretAlias);
if (info->preallocate) {
if (info->size_arg > info->allocation)
@@ -761,7 +761,8 @@ storageBackendCreateQemuImgCheckEncryption(int format,
{
virStorageEncryptionPtr enc = vol->target.encryption;
- if (format == VIR_STORAGE_FILE_RAW) {
+ if (format == VIR_STORAGE_FILE_RAW ||
+ format == VIR_STORAGE_FILE_QCOW2) {
if (enc->format != VIR_STORAGE_ENCRYPTION_FORMAT_LUKS) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("unsupported volume encryption format %d"),
@@ -927,21 +928,34 @@ storageBackendCreateQemuImgSecretObject(virCommandPtr cmd,
}
-/* Add a --image-opts to the qemu-img resize command line:
+/* Add a --image-opts to the qemu-img resize command line for use
+ * with encryption:
* --image-opts driver=luks,file.filename=$volpath,key-secret=$secretAlias
+ * or
+ * --image-opts driver=qcow2,file.filename=$volpath,encrypt.key-secret=$secretAlias
*
- * NB: format=raw is assumed
*/
static int
storageBackendResizeQemuImgImageOpts(virCommandPtr cmd,
+ int format,
const char *path,
const char *secretAlias)
{
g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER;
g_autofree char *commandStr = NULL;
+ const char *encprefix;
+ const char *driver;
- virBufferAsprintf(&buf, "driver=luks,key-secret=%s,file.filename=",
- secretAlias);
+ if (format == VIR_STORAGE_FILE_QCOW2) {
+ driver = "qcow2";
+ encprefix = "encrypt.";
+ } else {
+ driver = "luks";
+ encprefix = "";
+ }
+
+ virBufferAsprintf(&buf, "driver=%s,%skey-secret=%s,file.filename=",
+ driver, encprefix, secretAlias);
virQEMUBuildBufferEscapeComma(&buf, path);
commandStr = virBufferContentAndReset(&buf);
@@ -1006,6 +1020,16 @@ virStorageBackendCreateQemuImgSetInfo(virStoragePoolObjPtr pool,
return -1;
}
}
+ if (inputvol && inputvol->target.format == VIR_STORAGE_FILE_RAW &&
+ inputvol->target.encryption) {
+ if (vol->target.encryption->format == VIR_STORAGE_ENCRYPTION_FORMAT_LUKS) {
+ info->type = "luks";
+ } else {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("Only luks encryption is supported for raw files"));
+ return -1;
+ }
+ }
if (inputvol &&
storageBackendCreateQemuImgSetInput(inputvol, convertStep, info) < 0)
@@ -1056,6 +1080,8 @@ virStorageBackendCreateQemuImgCmdFromVol(virStoragePoolObjPtr pool,
virStorageEncryptionPtr inputenc = inputvol ? inputvol->target.encryption : NULL;
virStorageEncryptionInfoDefPtr encinfo = NULL;
g_autofree char *inputSecretAlias = NULL;
+ const char *encprefix;
+ const char *inputencprefix;
virCheckFlags(VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA, NULL);
@@ -1134,24 +1160,34 @@ virStorageBackendCreateQemuImgCmdFromVol(virStoragePoolObjPtr pool,
virCommandAddArgFormat(cmd, "%lluK", info.size_arg);
} else {
/* source */
- if (inputenc)
+ if (inputenc) {
+ if (inputvol->target.format == VIR_STORAGE_FILE_QCOW2)
+ inputencprefix = "encrypt.";
+ else
+ inputencprefix = "";
virCommandAddArgFormat(cmd,
- "driver=luks,file.filename=%s,key-secret=%s",
- info.inputPath, inputSecretAlias);
- else
+ "driver=%s,file.filename=%s,%skey-secret=%s",
+ info.inputType, info.inputPath, inputencprefix, inputSecretAlias);
+ } else {
virCommandAddArgFormat(cmd, "driver=%s,file.filename=%s",
info.inputType ? info.inputType : "raw",
info.inputPath);
+ }
/* dest */
- if (enc)
+ if (enc) {
+ if (vol->target.format == VIR_STORAGE_FILE_QCOW2)
+ encprefix = "encrypt.";
+ else
+ encprefix = "";
+
virCommandAddArgFormat(cmd,
- "driver=%s,file.filename=%s,key-secret=%s",
- info.type, info.path, info.secretAlias);
- else
+ "driver=%s,file.filename=%s,%skey-secret=%s",
+ info.type, info.path, encprefix, info.secretAlias);
+ } else {
virCommandAddArgFormat(cmd, "driver=%s,file.filename=%s",
info.type, info.path);
-
+ }
}
VIR_FREE(info.secretAlias);
@@ -2276,7 +2312,9 @@ storageBackendResizeQemuImg(virStoragePoolObjPtr pool,
secretAlias) < 0)
goto cleanup;
- if (storageBackendResizeQemuImgImageOpts(cmd, vol->target.path,
+ if (storageBackendResizeQemuImgImageOpts(cmd,
+ vol->target.format,
+ vol->target.path,
secretAlias) < 0)
goto cleanup;
}
diff --git a/src/util/virqemu.c b/src/util/virqemu.c
index 25d6fd35c5..bbb38eed75 100644
--- a/src/util/virqemu.c
+++ b/src/util/virqemu.c
@@ -28,6 +28,7 @@
#include "virqemu.h"
#include "virstring.h"
#include "viralloc.h"
+#include "virstoragefile.h"
#define VIR_FROM_THIS VIR_FROM_NONE
@@ -407,36 +408,46 @@ virQEMUBuildBufferEscapeComma(virBufferPtr buf, const char *str)
*/
void
virQEMUBuildQemuImgKeySecretOpts(virBufferPtr buf,
+ int format,
virStorageEncryptionInfoDefPtr encinfo,
const char *alias)
{
- virBufferAsprintf(buf, "key-secret=%s,", alias);
+ const char *encprefix;
+
+ if (format == VIR_STORAGE_FILE_QCOW2) {
+ virBufferAsprintf(buf, "encrypt.format=luks,");
+ encprefix = "encrypt.";
+ } else {
+ encprefix = "";
+ }
+
+ virBufferAsprintf(buf, "%skey-secret=%s,", encprefix, alias);
if (!encinfo->cipher_name)
return;
- virBufferAddLit(buf, "cipher-alg=");
+ virBufferAsprintf(buf, "%scipher-alg=", encprefix);
virQEMUBuildBufferEscapeComma(buf, encinfo->cipher_name);
virBufferAsprintf(buf, "-%u,", encinfo->cipher_size);
if (encinfo->cipher_mode) {
- virBufferAddLit(buf, "cipher-mode=");
+ virBufferAsprintf(buf, "%scipher-mode=", encprefix);
virQEMUBuildBufferEscapeComma(buf, encinfo->cipher_mode);
virBufferAddLit(buf, ",");
}
if (encinfo->cipher_hash) {
- virBufferAddLit(buf, "hash-alg=");
+ virBufferAsprintf(buf, "%shash-alg=", encprefix);
virQEMUBuildBufferEscapeComma(buf, encinfo->cipher_hash);
virBufferAddLit(buf, ",");
}
if (!encinfo->ivgen_name)
return;
- virBufferAddLit(buf, "ivgen-alg=");
+ virBufferAsprintf(buf, "%sivgen-alg=", encprefix);
virQEMUBuildBufferEscapeComma(buf, encinfo->ivgen_name);
virBufferAddLit(buf, ",");
if (encinfo->ivgen_hash) {
- virBufferAddLit(buf, "ivgen-hash-alg=");
+ virBufferAsprintf(buf, "%sivgen-hash-alg=", encprefix);
virQEMUBuildBufferEscapeComma(buf, encinfo->ivgen_hash);
virBufferAddLit(buf, ",");
}
diff --git a/src/util/virqemu.h b/src/util/virqemu.h
index b1296cb657..be14c04d51 100644
--- a/src/util/virqemu.h
+++ b/src/util/virqemu.h
@@ -60,6 +60,7 @@ char *virQEMUBuildDriveCommandlineFromJSON(virJSONValuePtr src);
void virQEMUBuildBufferEscapeComma(virBufferPtr buf, const char *str);
void virQEMUBuildQemuImgKeySecretOpts(virBufferPtr buf,
+ int format,
virStorageEncryptionInfoDefPtr enc,
const char *alias)
ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3);
--
2.26.2
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