Fix padding of encrypted data (bz #1452622)

0001-Fix-padding-of-encrypted-data.patch

@@ -0,0 +1,55 @@
+From: "Daniel P. Berrange" <berrange@redhat.com>
+Date: Tue, 2 May 2017 11:32:43 +0100
+Subject: [PATCH] Fix padding of encrypted data
+
+If we are encoding a block of data that is 16 bytes in length,
+we cannot leave it as 16 bytes, we must pad it out to the next
+block boundary, 32 bytes. Without this padding, the decoder will
+incorrectly treat the last byte of plain text as the padding
+length, as it can't distinguish padded from non-padded data.
+
+The problem exhibited itself when using a 16 byte passphrase
+for a LUKS volume
+
+  $ virsh secret-set-value 55806c7d-8e93-456f-829b-607d8c198367 \
+       $(echo -n 1234567812345678 | base64)
+  Secret value set
+
+  $ virsh start demo
+  error: Failed to start domain demo
+  error: internal error: process exited while connecting to monitor: >>>>>>>>>>Len 16
+  2017-05-02T10:35:40.016390Z qemu-system-x86_64: -object \
+    secret,id=virtio-disk1-luks-secret0,data=SEtNi5vDUeyseMKHwc1c1Q==,\
+    keyid=masterKey0,iv=zm7apUB1A6dPcH53VW960Q==,format=base64: \
+    Incorrect number of padding bytes (56) found on decrypted data
+
+Notice how the padding '56' corresponds to the ordinal value of
+the character '8'.
+
+Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
+(cherry picked from commit 71890992daf37ec78b00b4ce873369421dc99731)
+---
+ src/util/vircrypto.c | 10 ++++++++--
+ 1 file changed, 8 insertions(+), 2 deletions(-)
+
+diff --git a/src/util/vircrypto.c b/src/util/vircrypto.c
+index 03410a1..8f1e0b7 100644
+--- a/src/util/vircrypto.c
++++ b/src/util/vircrypto.c
+@@ -152,8 +152,14 @@ virCryptoEncryptDataAESgnutls(gnutls_cipher_algorithm_t gnutls_enc_alg,
+     uint8_t *ciphertext;
+     size_t ciphertextlen;
+ 
+-    /* Allocate a padded buffer, copy in the data */
+-    ciphertextlen = VIR_ROUND_UP(datalen, 16);
++    /* Allocate a padded buffer, copy in the data.
++     *
++     * NB, we must *always* have at least 1 byte of
++     * padding - we can't skip it on multiples of
++     * 16, otherwise decoder can't distinguish padded
++     * data from non-padded data. Hence datalen + 1
++     */
++    ciphertextlen = VIR_ROUND_UP(datalen + 1, 16);
+     if (VIR_ALLOC_N(ciphertext, ciphertextlen) < 0)
+         return -1;
+     memcpy(ciphertext, data, datalen);

libvirt.spec

@@ -220,7 +220,7 @@
 Summary: Library providing a simple virtualization API
 Name: libvirt
 Version: 2.2.1
-Release: 1%{?dist}%{?extra_release}
+Release: 2%{?dist}%{?extra_release}
 License: LGPLv2+
 Group: Development/Libraries
 BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root
@@ -231,6 +231,9 @@ URL: http://libvirt.org/
 %endif
 Source: http://libvirt.org/sources/%{?mainturl}libvirt-%{version}.tar.xz
 
+# Fix padding of encrypted data (bz #1452622)
+Patch0001: 0001-Fix-padding-of-encrypted-data.patch
+
 Requires: libvirt-daemon = %{version}-%{release}
 Requires: libvirt-daemon-config-network = %{version}-%{release}
 Requires: libvirt-daemon-config-nwfilter = %{version}-%{release}
@@ -1914,6 +1917,9 @@ exit 0
 
 
 %changelog
+* Tue May 30 2017 Cole Robinson <crobinso@redhat.com> - 2.2.1-2
+- Fix padding of encrypted data (bz #1452622)
+
 * Wed May 10 2017 Cole Robinson <crobinso@redhat.com> - 2.2.1-1
 - Rebased to version 2.2.1
 - Fix spice port allocation collisions (bz #1390413)