From 629e64743474a040863ef1267eb48568c6e3e80c Mon Sep 17 00:00:00 2001

Message-Id: <629e64743474a040863ef1267eb48568c6e3e80c@dist-git>

From: John Ferlan <jferlan@redhat.com>

Date: Mon, 25 Jul 2016 12:42:49 -0400

Subject: [PATCH] encryption: Add <cipher> and <ivgen> to encryption

https://bugzilla.redhat.com/show_bug.cgi?id=1301021

For a luks device, allow the configuration of a specific cipher to be

used for encrypting the volume.

Signed-off-by: John Ferlan <jferlan@redhat.com>

(cherry picked from commit 2552fec248c665f3417a5d36840555da6bbe96a4)

---

 docs/formatstorageencryption.html.in               |  83 ++++++++++++-

 docs/schemas/storagecommon.rng                     |  44 ++++++-

 src/conf/domain_conf.c                             |  11 ++

 src/util/virstorageencryption.c                    | 136 +++++++++++++++++++++

 src/util/virstorageencryption.h                    |  14 +++

 .../qemuxml2argv-luks-disk-cipher.xml              |  45 +++++++

 .../qemuxml2xmlout-luks-disk-cipher.xml            |   1 +

 tests/qemuxml2xmltest.c                            |   1 +

 tests/storagevolxml2xmlin/vol-luks-cipher.xml      |  23 ++++

 tests/storagevolxml2xmlout/vol-luks-cipher.xml     |  23 ++++

 tests/storagevolxml2xmltest.c                      |   1 +

 11 files changed, 376 insertions(+), 6 deletions(-)

 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-luks-disk-cipher.xml

 create mode 120000 tests/qemuxml2xmloutdata/qemuxml2xmlout-luks-disk-cipher.xml

 create mode 100644 tests/storagevolxml2xmlin/vol-luks-cipher.xml

 create mode 100644 tests/storagevolxml2xmlout/vol-luks-cipher.xml

diff --git a/docs/formatstorageencryption.html.in b/docs/formatstorageencryption.html.in

index 380763e..f2b0ffd 100644

--- a/docs/formatstorageencryption.html.in

+++ b/docs/formatstorageencryption.html.in

@@ -68,6 +68,60 @@

       be used as the passphrase to decrypt the volume.

       Since 2.1.0.

+    

+      For volume creation, it is possible to specify the encryption

+      algorithm used to encrypt the luks volume. The following two

+      optional elements may be provided for that purpose. It is hypervisor

+      dependent as to which algorithms are supported. The default algorithm

+      used by the storage driver backend when using qemu-img to create

+      the volume is 'aes-256-cbc' using 'essiv' for initialization vector

+      generation and 'sha256' hash algorithm for both the cipher and the

+      initialization vector generation.

+    

+

+    

+      
cipher

+      
This element describes the cipher algorithm to be used to either

+          encrypt or decrypt the luks volume. This element has the following

+          attributes:

+          

+            
name

+            
The name of the cipher algorithm used for data encryption,

+            such as 'aes', 'des', 'cast5', 'serpent', 'twofish', etc.

+            Support of the specific algorithm is storage driver

+            implementation dependent.

+            
size

+            
The size of the cipher in bits, such as '256', '192', '128',

+            etc. Support of the specific size for a specific cipher is

+            hypervisor dependent.

+            
mode

+            
An optional cipher algorithm mode such as 'cbc', 'xts',

+            'ecb', etc. Support of the specific cipher mode is

+            hypervisor dependent.

+            
hash

+            
An optional master key hash algorithm such as 'md5', 'sha1',

+            'sha256', etc. Support of the specific hash algorithm is

+            hypervisor dependent.

+          

+      

+      
ivgen

+      
This optional element describes the initialization vector

+          generation algorithm used in conjunction with the

+          cipher. If the cipher is not provided,

+          then an error will be generated by the parser.

+          

+            
name

+            
The name of the algorithm, such as 'plain', 'plain64',

+            'essiv', etc. Support of the specific algorithm is hypervisor

+            dependent.

+            
hash

+            
An optional hash algorithm such as 'md5', 'sha1', 'sha256',

+            etc. Support of the specific ivgen hash algorithm is hypervisor

+            dependent.

+          

+      

+    

+

     
Examples

@@ -81,9 +135,12 @@

       </encryption>

-      Here is a simple example, specifying use of the luks format

-      where it's assumed that a secret has been defined using a

-      usage element with a id of "luks_example":

+      Assuming a 

+      luks secret is already defined using a

+      usage element with an name of "luks_example",

+      a simple example specifying use of the luks format

+      for either volume creation without a specific cipher being defined or

+      as part of a domain volume definition:

       <encryption format='luks'>

@@ -91,5 +148,25 @@

       </encryption>

+    

+      Here is an example, specifying use of the luks format for

+      a specific cipher algorihm for volume creation:

+    

+    

+      <volume>

+        <name>twofish.luks</name>

+        <capacity unit='G'>5</capacity>

+        <target>

+          <path>/var/lib/libvirt/images/demo.luks</path>

+          <format type='luks'/>

+          <encryption format='luks'>

+             <secret type='passphrase' usage='luks_example'/>

+             <cipher name='twofish' size='256' mode='cbc' hash='sha256'/>

+             <ivgen name='plain64' hash='sha256'/>

+          </encryption>

+        </target>

+      </volume>

+    

+

   </body>

 </html>

diff --git a/docs/schemas/storagecommon.rng b/docs/schemas/storagecommon.rng

index 63b55b4..316fbae 100644

--- a/docs/schemas/storagecommon.rng

+++ b/docs/schemas/storagecommon.rng

@@ -15,9 +15,19 @@

           <value>luks</value>

         </choice>

       </attribute>

-      <zeroOrMore>

-        <ref name='secret'/>

-      </zeroOrMore>

+      <interleave>

+        <zeroOrMore>

+          <ref name='secret'/>

+        </zeroOrMore>

+        <optional>

+          <element name='cipher'>

+            <ref name='keycipher'/>

+          </element>

+          <element name='ivgen'>

+            <ref name='keyivgen'/>

+          </element>

+        </optional>

+      </interleave>

     </element>

   </define>

@@ -136,4 +146,32 @@

     </optional>

   </define>

+  <define name='keycipher'>

+    <attribute name='name'>

+      <text/>

+    </attribute>

+    <attribute name='size'>

+      <ref name="unsignedInt"/>

+    </attribute>

+    <optional>

+      <attribute name='mode'>

+        <text/>

+      </attribute>

+      <attribute name='hash'>

+        <text/>

+      </attribute>

+    </optional>

+  </define>

+

+  <define name='keyivgen'>

+    <attribute name='name'>

+      <text/>

+    </attribute>

+    <optional>

+      <attribute name='hash'>

+        <text/>

+      </attribute>

+    </optional>

+  </define>

+

 </grammar>

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c

index 8b9b623..abf889a 100644

--- a/src/conf/domain_conf.c

+++ b/src/conf/domain_conf.c

@@ -7869,6 +7869,17 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,

         def->startupPolicy = val;

     }

+    if (encryption) {

+        if (encryption->format == VIR_STORAGE_ENCRYPTION_FORMAT_LUKS &&

+            encryption->encinfo.cipher_name) {

+

+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",

+                           _("supplying the <cipher> for a domain is "

+                             "unnecessary"));

+            goto error;

+        }

+    }

+

     def->dst = target;

     target = NULL;

     def->src->auth = authdef;

diff --git a/src/util/virstorageencryption.c b/src/util/virstorageencryption.c

index 2b59420..116a235 100644

--- a/src/util/virstorageencryption.c

+++ b/src/util/virstorageencryption.c

@@ -35,6 +35,7 @@

 #include "viruuid.h"

 #include "virfile.h"

 #include "virsecret.h"

+#include "virstring.h"

 #define VIR_FROM_THIS VIR_FROM_STORAGE

@@ -46,6 +47,17 @@ VIR_ENUM_IMPL(virStorageEncryptionFormat,

               "default", "qcow", "luks")

 static void

+virStorageEncryptionInfoDefFree(virStorageEncryptionInfoDefPtr def)

+{

+    VIR_FREE(def->cipher_name);

+    VIR_FREE(def->cipher_mode);

+    VIR_FREE(def->cipher_hash);

+    VIR_FREE(def->ivgen_name);

+    VIR_FREE(def->ivgen_hash);

+}

+

+

+static void

 virStorageEncryptionSecretFree(virStorageEncryptionSecretPtr secret)

 {

     if (!secret)

@@ -64,6 +76,7 @@ virStorageEncryptionFree(virStorageEncryptionPtr enc)

     for (i = 0; i < enc->nsecrets; i++)

         virStorageEncryptionSecretFree(enc->secrets[i]);

+    virStorageEncryptionInfoDefFree(&enc->encinfo);

     VIR_FREE(enc->secrets);

     VIR_FREE(enc);

 }

@@ -81,6 +94,23 @@ virStorageEncryptionSecretCopy(const virStorageEncryptionSecret *src)

     return ret;

 }

+

+static int

+virStorageEncryptionInfoDefCopy(const virStorageEncryptionInfoDef *src,

+                                virStorageEncryptionInfoDefPtr dst)

+{

+    dst->cipher_size = src->cipher_size;

+    if (VIR_STRDUP(dst->cipher_name, src->cipher_name) < 0 ||

+        VIR_STRDUP(dst->cipher_mode, src->cipher_mode) < 0 ||

+        VIR_STRDUP(dst->cipher_hash, src->cipher_hash) < 0 ||

+        VIR_STRDUP(dst->ivgen_name, src->ivgen_name) < 0 ||

+        VIR_STRDUP(dst->ivgen_hash, src->ivgen_hash) < 0)

+        return -1;

+

+    return 0;

+}

+

+

 virStorageEncryptionPtr

 virStorageEncryptionCopy(const virStorageEncryption *src)

 {

@@ -101,6 +131,9 @@ virStorageEncryptionCopy(const virStorageEncryption *src)

             goto error;

     }

+    if (virStorageEncryptionInfoDefCopy(&src->encinfo, &ret->encinfo) < 0)

+        goto error;

+

     return ret;

  error:

@@ -154,6 +187,61 @@ virStorageEncryptionSecretParse(xmlXPathContextPtr ctxt,

     return NULL;

 }

+

+static int

+virStorageEncryptionInfoParseCipher(xmlNodePtr info_node,

+                                    virStorageEncryptionInfoDefPtr info)

+{

+    int ret = -1;

+    char *size_str = NULL;

+

+    if (!(info->cipher_name = virXMLPropString(info_node, "name"))) {

+        virReportError(VIR_ERR_XML_ERROR, "%s",

+                       _("cipher info missing 'name' attribute"));

+        goto cleanup;

+    }

+

+    if ((size_str = virXMLPropString(info_node, "size")) &&

+        virStrToLong_uip(size_str, NULL, 10, &info->cipher_size) < 0) {

+        virReportError(VIR_ERR_XML_ERROR,

+                       _("cannot parse cipher size: '%s'"),

+                       size_str);

+        goto cleanup;

+    }

+

+    if (!size_str) {

+        virReportError(VIR_ERR_XML_ERROR, "%s",

+                       _("cipher info missing 'size' attribute"));

+        goto cleanup;

+    }

+

+    info->cipher_mode = virXMLPropString(info_node, "mode");

+    info->cipher_hash = virXMLPropString(info_node, "hash");

+

+    ret = 0;

+

+ cleanup:

+    VIR_FREE(size_str);

+    return ret;

+}

+

+

+static int

+virStorageEncryptionInfoParseIvgen(xmlNodePtr info_node,

+                                   virStorageEncryptionInfoDefPtr info)

+{

+    if (!(info->ivgen_name = virXMLPropString(info_node, "name"))) {

+        virReportError(VIR_ERR_XML_ERROR, "%s",

+                       _("missing ivgen info name string"));

+        return -1;

+    }

+

+    info->ivgen_hash = virXMLPropString(info_node, "hash");

+

+    return 0;

+}

+

+

 static virStorageEncryptionPtr

 virStorageEncryptionParseXML(xmlXPathContextPtr ctxt)

 {

@@ -197,6 +285,28 @@ virStorageEncryptionParseXML(xmlXPathContextPtr ctxt)

         VIR_FREE(nodes);

     }

+    if (ret->format == VIR_STORAGE_ENCRYPTION_FORMAT_LUKS) {

+        xmlNodePtr tmpnode;

+

+        if ((tmpnode = virXPathNode("./cipher[1]", ctxt))) {

+            if (virStorageEncryptionInfoParseCipher(tmpnode, &ret->encinfo) < 0)

+                goto cleanup;

+        }

+

+        if ((tmpnode = virXPathNode("./ivgen[1]", ctxt))) {

+            /* If no cipher node, then fail */

+            if (!ret->encinfo.cipher_name) {

+                virReportError(VIR_ERR_XML_ERROR, "%s",

+                                _("ivgen element found, but cipher is missing"));

+                goto cleanup;

+            }

+

+            if (virStorageEncryptionInfoParseIvgen(tmpnode, &ret->encinfo) < 0)

+                goto cleanup;

+        }

+    }

+

+

     return ret;

  cleanup:

@@ -251,6 +361,28 @@ virStorageEncryptionSecretFormat(virBufferPtr buf,

     return 0;

 }

+

+static void

+virStorageEncryptionInfoDefFormat(virBufferPtr buf,

+                                  const virStorageEncryptionInfoDef *enc)

+{

+    virBufferEscapeString(buf, "<cipher name='%s'", enc->cipher_name);

+    virBufferAsprintf(buf, " size='%u'", enc->cipher_size);

+    if (enc->cipher_mode)

+        virBufferEscapeString(buf, " mode='%s'", enc->cipher_mode);

+    if (enc->cipher_hash)

+        virBufferEscapeString(buf, " hash='%s'", enc->cipher_hash);

+    virBufferAddLit(buf, "/>\n");

+

+    if (enc->ivgen_name) {

+        virBufferEscapeString(buf, "<ivgen name='%s'", enc->ivgen_name);

+        if (enc->ivgen_hash)

+            virBufferEscapeString(buf, " hash='%s'", enc->ivgen_hash);

+        virBufferAddLit(buf, "/>\n");

+    }

+}

+

+

 int

 virStorageEncryptionFormat(virBufferPtr buf,

                            virStorageEncryptionPtr enc)

@@ -271,6 +403,10 @@ virStorageEncryptionFormat(virBufferPtr buf,

             return -1;

     }

+    if (enc->format == VIR_STORAGE_ENCRYPTION_FORMAT_LUKS &&

+        enc->encinfo.cipher_name)

+        virStorageEncryptionInfoDefFormat(buf, &enc->encinfo);

+

     virBufferAdjustIndent(buf, -2);

     virBufferAddLit(buf, "</encryption>\n");

diff --git a/src/util/virstorageencryption.h b/src/util/virstorageencryption.h

index 5e1be3b..fa439fb 100644

--- a/src/util/virstorageencryption.h

+++ b/src/util/virstorageencryption.h

@@ -44,6 +44,18 @@ struct _virStorageEncryptionSecret {

     virSecretLookupTypeDef seclookupdef;

 };

+/* It's possible to dictate the cipher and if necessary iv */

+typedef struct _virStorageEncryptionInfoDef virStorageEncryptionInfoDef;

+typedef virStorageEncryptionInfoDef *virStorageEncryptionInfoDefPtr;

+struct _virStorageEncryptionInfoDef {

+    unsigned int cipher_size;

+    char *cipher_name;

+    char *cipher_mode;

+    char *cipher_hash;

+    char *ivgen_name;

+    char *ivgen_hash;

+};

+

 typedef enum {

     /* "default" is only valid for volume creation */

     VIR_STORAGE_ENCRYPTION_FORMAT_DEFAULT = 0,

@@ -61,6 +73,8 @@ struct _virStorageEncryption {

     size_t nsecrets;

     virStorageEncryptionSecretPtr *secrets;

+

+    virStorageEncryptionInfoDef encinfo;

 };

 virStorageEncryptionPtr virStorageEncryptionCopy(const virStorageEncryption *src)

diff --git a/tests/qemuxml2argvdata/qemuxml2argv-luks-disk-cipher.xml b/tests/qemuxml2argvdata/qemuxml2argv-luks-disk-cipher.xml

new file mode 100644

index 0000000..9ce15c0

--- /dev/null

+++ b/tests/qemuxml2argvdata/qemuxml2argv-luks-disk-cipher.xml

@@ -0,0 +1,45 @@

+<domain type='qemu'>

+  <name>encryptdisk</name>

+  <uuid>496898a6-e6ff-f7c8-5dc2-3cf410945ee9</uuid>

+  <memory unit='KiB'>1048576</memory>

+  <currentMemory unit='KiB'>524288</currentMemory>

+  <vcpu placement='static'>1</vcpu>

+  <os>

+    <type arch='x86_64' machine='pc-i440fx-2.1'>hvm</type>

+    <boot dev='hd'/>

+  </os>

+  <clock offset='utc'/>

+  <on_poweroff>destroy</on_poweroff>

+  <on_reboot>restart</on_reboot>

+  <on_crash>destroy</on_crash>

+  <devices>

+    <emulator>/usr/bin/qemu</emulator>

+    <disk type='file' device='disk'>

+      <driver name='qemu' type='luks'/>

+      <source file='/storage/guest_disks/encryptdisk'/>

+      <target dev='vda' bus='virtio'/>

+      <encryption format='luks'>

+        <secret type='passphrase' uuid='0a81f5b2-8403-7b23-c8d6-21ccc2f80d6f'/>

+      </encryption>

+      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>

+    </disk>

+    <disk type='file' device='disk'>

+      <driver name='qemu' type='luks'/>

+      <source file='/storage/guest_disks/encryptdisk2'/>

+      <target dev='vdb' bus='virtio'/>

+      <encryption format='luks'>

+        <secret type='passphrase' usage='mycluster_myname'/>

+      </encryption>

+      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>

+    </disk>

+    <controller type='usb' index='0'>

+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>

+    </controller>

+    <controller type='pci' index='0' model='pci-root'/>

+    <input type='mouse' bus='ps2'/>

+    <input type='keyboard' bus='ps2'/>

+    <memballoon model='virtio'>

+      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>

+    </memballoon>

+  </devices>

+</domain>

diff --git a/tests/qemuxml2xmloutdata/qemuxml2xmlout-luks-disk-cipher.xml b/tests/qemuxml2xmloutdata/qemuxml2xmlout-luks-disk-cipher.xml

new file mode 120000

index 0000000..fa55233

--- /dev/null

+++ b/tests/qemuxml2xmloutdata/qemuxml2xmlout-luks-disk-cipher.xml

@@ -0,0 +1 @@

+../qemuxml2argvdata/qemuxml2argv-luks-disk-cipher.xml

\ No newline at end of file

diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c

index a757fdb..d00d209 100644

--- a/tests/qemuxml2xmltest.c

+++ b/tests/qemuxml2xmltest.c

@@ -503,6 +503,7 @@ mymain(void)

     DO_TEST("encrypted-disk");

     DO_TEST("encrypted-disk-usage");

     DO_TEST("luks-disks");

+    DO_TEST("luks-disk-cipher");

     DO_TEST("memtune");

     DO_TEST("memtune-unlimited");

     DO_TEST("blkiotune");

diff --git a/tests/storagevolxml2xmlin/vol-luks-cipher.xml b/tests/storagevolxml2xmlin/vol-luks-cipher.xml

new file mode 100644

index 0000000..009246f

--- /dev/null

+++ b/tests/storagevolxml2xmlin/vol-luks-cipher.xml

@@ -0,0 +1,23 @@

+<volume>

+  <name>LuksDemo.img</name>

+  <key>/var/lib/libvirt/images/LuksDemo.img</key>

+  <source>

+  </source>

+  <capacity unit="G">5</capacity>

+  <allocation>294912</allocation>

+  <target>

+    <path>/var/lib/libvirt/images/LuksDemo.img</path>

+    <format type='luks'/>

+    <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' usage='mumblyfratz'/>

+      <cipher name='serpent' size='256' mode='cbc' hash='sha256'/>

+      <ivgen name='plain64' hash='sha256'/>

+    </encryption>

+  </target>

+</volume>

diff --git a/tests/storagevolxml2xmlout/vol-luks-cipher.xml b/tests/storagevolxml2xmlout/vol-luks-cipher.xml

new file mode 100644

index 0000000..9014849

--- /dev/null

+++ b/tests/storagevolxml2xmlout/vol-luks-cipher.xml

@@ -0,0 +1,23 @@

+<volume type='file'>

+  <name>LuksDemo.img</name>

+  <key>/var/lib/libvirt/images/LuksDemo.img</key>

+  <source>

+  </source>

+  <capacity unit='bytes'>5368709120</capacity>

+  <allocation unit='bytes'>294912</allocation>

+  <target>

+    <path>/var/lib/libvirt/images/LuksDemo.img</path>

+    <format type='luks'/>

+    <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' usage='mumblyfratz'/>

+      <cipher name='serpent' size='256' mode='cbc' hash='sha256'/>

+      <ivgen name='plain64' hash='sha256'/>

+    </encryption>

+  </target>

+</volume>

diff --git a/tests/storagevolxml2xmltest.c b/tests/storagevolxml2xmltest.c

index a36a706..db82bea 100644

--- a/tests/storagevolxml2xmltest.c

+++ b/tests/storagevolxml2xmltest.c

@@ -106,6 +106,7 @@ mymain(void)

     DO_TEST("pool-dir", "vol-qcow2-0.10-lazy");

     DO_TEST("pool-dir", "vol-qcow2-nobacking");

     DO_TEST("pool-dir", "vol-luks");

+    DO_TEST("pool-dir", "vol-luks-cipher");

     DO_TEST("pool-disk", "vol-partition");

     DO_TEST("pool-logical", "vol-logical");

     DO_TEST("pool-logical", "vol-logical-backing");

-- 

2.9.2