storage: add support for qcow2 LUKS encryption

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.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

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 (inputvol->target.encryption->format == VIR_STORAGE_ENCRYPTION_FORMAT_LUKS) {
+            info->inputType = "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;
     }

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) {
+        virBufferAddLit(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, ",");
     }

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);

tests/storagevolxml2argvdata/qcow2-luks-convert-encrypt.argv

@@ -0,0 +1,18 @@
+qemu-img \
+create \
+-f qcow2 \
+--object secret,id=OtherDemoLuks.img_encrypt0,file=/path/to/secretFile \
+-o encrypt.format=luks,encrypt.key-secret=OtherDemoLuks.img_encrypt0,\
+compat=0.10 /var/lib/libvirt/images/OtherDemoLuks.img 5242880K
+qemu-img \
+convert \
+--image-opts \
+-n \
+--target-image-opts \
+--object secret,id=OtherDemoLuks.img_encrypt0,file=/path/to/secretFile \
+--object secret,id=OtherDemoLuksConvert.img_encrypt0,\
+file=/path/to/inputSecretFile driver=qcow2,\
+file.filename=/var/lib/libvirt/images/OtherDemoLuksConvert.img,\
+encrypt.key-secret=OtherDemoLuksConvert.img_encrypt0 driver=qcow2,\
+file.filename=/var/lib/libvirt/images/OtherDemoLuks.img,\
+encrypt.key-secret=OtherDemoLuks.img_encrypt0

tests/storagevolxml2argvdata/qcow2-luks-convert-encrypt2fileqcow2.argv

@@ -0,0 +1,14 @@
+qemu-img \
+create \
+-f qcow2 \
+-o compat=0.10 /var/lib/libvirt/images/sparse-qcow2.img 1073741824K
+qemu-img \
+convert \
+--image-opts \
+-n \
+--target-image-opts \
+--object secret,id=OtherDemoLuksConvert.img_encrypt0,\
+file=/path/to/inputSecretFile driver=qcow2,\
+file.filename=/var/lib/libvirt/images/OtherDemoLuksConvert.img,\
+encrypt.key-secret=OtherDemoLuksConvert.img_encrypt0 driver=qcow2,\
+file.filename=/var/lib/libvirt/images/sparse-qcow2.img

tests/storagevolxml2argvdata/qcow2-luks-convert-encrypt2fileraw.argv

@@ -0,0 +1,13 @@
+qemu-img \
+create \
+-f raw /var/lib/libvirt/images/sparse.img 1073741824K
+qemu-img \
+convert \
+--image-opts \
+-n \
+--target-image-opts \
+--object secret,id=OtherDemoLuksConvert.img_encrypt0,\
+file=/path/to/inputSecretFile driver=qcow2,\
+file.filename=/var/lib/libvirt/images/OtherDemoLuksConvert.img,\
+encrypt.key-secret=OtherDemoLuksConvert.img_encrypt0 driver=raw,\
+file.filename=/var/lib/libvirt/images/sparse.img

tests/storagevolxml2argvdata/qcow2-luks.argv

@@ -0,0 +1,8 @@
+qemu-img \
+create \
+-f qcow2 \
+-b /dev/null \
+--object secret,id=OtherDemoLuks.img_encrypt0,file=/path/to/secretFile \
+-o backing_fmt=raw,encrypt.format=luks,\
+encrypt.key-secret=OtherDemoLuks.img_encrypt0,\
+compat=0.10 /var/lib/libvirt/images/OtherDemoLuks.img 5242880K

tests/storagevolxml2argvtest.c

@@ -255,6 +255,9 @@ mymain(void)
     DO_TEST("pool-dir", "vol-luks-cipher",
             NULL, NULL,
             "luks-cipher", 0);
+    DO_TEST("pool-dir", "vol-qcow2-luks",
+            NULL, NULL,
+            "qcow2-luks", 0);
 
     DO_TEST("pool-dir", "vol-luks-convert",
             "pool-dir", "vol-file",
@@ -276,6 +279,18 @@ mymain(void)
             "pool-dir", "vol-luks-convert",
             "luks-convert-encrypt2fileqcow2", 0);
 
+    DO_TEST("pool-dir", "vol-qcow2-luks",
+            "pool-dir", "vol-qcow2-luks-convert",
+            "qcow2-luks-convert-encrypt", 0);
+
+    DO_TEST("pool-dir", "vol-file",
+            "pool-dir", "vol-qcow2-luks-convert",
+            "qcow2-luks-convert-encrypt2fileraw", 0);
+
+    DO_TEST("pool-dir", "vol-file-qcow2",
+            "pool-dir", "vol-qcow2-luks-convert",
+            "qcow2-luks-convert-encrypt2fileqcow2", 0);
+
     return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
 }
 

tests/storagevolxml2xmlin/vol-qcow2-luks-convert.xml

@@ -0,0 +1,31 @@
+<volume>
+  <name>OtherDemoLuksConvert.img</name>
+  <key>/var/lib/libvirt/images/OtherDemoLuksConvert.img</key>
+  <source>
+  </source>
+  <capacity unit="G">5</capacity>
+  <allocation>294912</allocation>
+  <target>
+    <path>/var/lib/libvirt/images/OtherDemoLuksConvert.img</path>
+    <format type='qcow2'/>
+    <permissions>
+      <mode>0644</mode>
+      <owner>0</owner>
+      <group>0</group>
+      <label>unconfined_u:object_r:virt_image_t:s0</label>
+    </permissions>
+    <encryption format='luks'>
+      <secret type='passphrase' uuid='e78d4b51-a2af-485f-b0f5-afca709a80f4'/>
+    </encryption>
+  </target>
+  <backingStore>
+    <path>/dev/null</path>
+    <format type='raw'/>
+    <permissions>
+      <mode>0644</mode>
+      <owner>0</owner>
+      <group>0</group>
+      <label>unconfined_u:object_r:virt_image_t:s0</label>
+    </permissions>
+  </backingStore>
+</volume>

tests/storagevolxml2xmlin/vol-qcow2-luks.xml

@@ -0,0 +1,31 @@
+<volume>
+  <name>OtherDemoLuks.img</name>
+  <key>/var/lib/libvirt/images/OtherDemoLuks.img</key>
+  <source>
+  </source>
+  <capacity unit="G">5</capacity>
+  <allocation>294912</allocation>
+  <target>
+    <path>/var/lib/libvirt/images/OtherDemoLuks.img</path>
+    <format type='qcow2'/>
+    <permissions>
+      <mode>0644</mode>
+      <owner>0</owner>
+      <group>0</group>
+      <label>unconfined_u:object_r:virt_image_t:s0</label>
+    </permissions>
+    <encryption format='luks'>
+      <secret type='passphrase' uuid='e78d4b51-a2af-485f-b0f5-afca709a80f4'/>
+    </encryption>
+  </target>
+  <backingStore>
+    <path>/dev/null</path>
+    <format type='raw'/>
+    <permissions>
+      <mode>0644</mode>
+      <owner>0</owner>
+      <group>0</group>
+      <label>unconfined_u:object_r:virt_image_t:s0</label>
+    </permissions>
+  </backingStore>
+</volume>

tests/storagevolxml2xmlout/vol-qcow2-luks.xml

@@ -0,0 +1,31 @@
+<volume type='file'>
+  <name>OtherDemoLuks.img</name>
+  <key>/var/lib/libvirt/images/OtherDemoLuks.img</key>
+  <source>
+  </source>
+  <capacity unit='bytes'>5368709120</capacity>
+  <allocation unit='bytes'>294912</allocation>
+  <target>
+    <path>/var/lib/libvirt/images/OtherDemoLuks.img</path>
+    <format type='qcow2'/>
+    <permissions>
+      <mode>0644</mode>
+      <owner>0</owner>
+      <group>0</group>
+      <label>unconfined_u:object_r:virt_image_t:s0</label>
+    </permissions>
+    <encryption format='luks'>
+      <secret type='passphrase' uuid='e78d4b51-a2af-485f-b0f5-afca709a80f4'/>
+    </encryption>
+  </target>
+  <backingStore>
+    <path>/dev/null</path>
+    <format type='raw'/>
+    <permissions>
+      <mode>0644</mode>
+      <owner>0</owner>
+      <group>0</group>
+      <label>unconfined_u:object_r:virt_image_t:s0</label>
+    </permissions>
+  </backingStore>
+</volume>

tests/storagevolxml2xmltest.c

@@ -87,6 +87,7 @@ mymain(void)
     DO_TEST("pool-dir", "vol-qcow2-0.10-lazy");
     DO_TEST("pool-dir", "vol-qcow2-nobacking");
     DO_TEST("pool-dir", "vol-qcow2-encryption");
+    DO_TEST("pool-dir", "vol-qcow2-luks");
     DO_TEST("pool-dir", "vol-luks");
     DO_TEST("pool-dir", "vol-luks-cipher");
     DO_TEST("pool-disk", "vol-partition");