Re: [libvirt PATCH 2/2] 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. Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- 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