From 02a80de4724dbc971f1b85534b249c69b69815d1 Mon Sep 17 00:00:00 2001
From: Tomas Mraz <tmraz@fedoraproject.org>
Date: Thu, 3 Jan 2013 14:54:02 +0100
Subject: [PATCH] allow empty passphrase in PBKDF2 needed for cryptsetup
 (=891266)

---
 libgcrypt-1.5.0-empty-passphrase.patch | 54 ++++++++++++++++++++++++++
 libgcrypt.spec                         |  8 +++-
 2 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 libgcrypt-1.5.0-empty-passphrase.patch

diff --git a/libgcrypt-1.5.0-empty-passphrase.patch b/libgcrypt-1.5.0-empty-passphrase.patch
new file mode 100644
index 0000000..c989420
--- /dev/null
+++ b/libgcrypt-1.5.0-empty-passphrase.patch
@@ -0,0 +1,54 @@
+commit 8528f1ba40e587dc17e02822e529fbd7ac69a189
+Author: Milan Broz <mbroz@redhat.com>
+Date:   Mon Oct 29 17:18:09 2012 +0100
+
+    PBKDF2: Allow empty passphrase.
+    
+    * cipher/kdf.c (gcry_kdf_derive): Allow empty passphrase for PBKDF2.
+    * tests/t-kdf.c (check_pbkdf2): Add test case for above.
+    --
+    
+    While it is insecure, the PBKDF2 implementations usually
+    allows to derive key only from salt.
+    
+    This particular case is used e.g. in cryptsetup when
+    you use empty file as keyfile for LUKS keyslot.
+    
+    Test vector is compared with two independent implementations.
+    
+    Signed-off-by: Milan Broz <mbroz@redhat.com>
+
+diff --git a/cipher/kdf.c b/cipher/kdf.c
+index d981022..46e8550 100644
+--- a/cipher/kdf.c
++++ b/cipher/kdf.c
+@@ -238,7 +238,7 @@ gcry_kdf_derive (const void *passphrase, size_t passphraselen,
+ {
+   gpg_err_code_t ec;
+ 
+-  if (!passphrase || !passphraselen)
++  if (!passphrase || (!passphraselen && algo != GCRY_KDF_PBKDF2))
+     {
+       ec = GPG_ERR_INV_DATA;
+       goto leave;
+diff --git a/tests/t-kdf.c b/tests/t-kdf.c
+index 7209525..06c0026 100644
+--- a/tests/t-kdf.c
++++ b/tests/t-kdf.c
+@@ -917,7 +917,15 @@ check_pbkdf2 (void)
+       16,
+       "\x56\xfa\x6a\xa7\x55\x48\x09\x9d\xcc\x37"
+       "\xd7\xf0\x34\x25\xe0\xc3"
+-    }
++    },
++    { /* empty password test, not in RFC-6070 */
++      "", 0,
++      "salt", 4,
++      2,
++      20,
++      "\x13\x3a\x4c\xe8\x37\xb4\xd2\x52\x1e\xe2"
++      "\xbf\x03\xe1\x1c\x71\xca\x79\x4e\x07\x97"
++    },
+   };
+   int tvidx;
+   gpg_error_t err;
diff --git a/libgcrypt.spec b/libgcrypt.spec
index 3a9ffb9..cc91552 100644
--- a/libgcrypt.spec
+++ b/libgcrypt.spec
@@ -1,6 +1,6 @@
 Name: libgcrypt
 Version: 1.5.0
-Release: 8%{?dist}
+Release: 9%{?dist}
 URL: http://www.gnupg.org/
 Source0: libgcrypt-%{version}-hobbled.tar.bz2
 # The original libgcrypt sources now contain potentially patented ECC
@@ -25,6 +25,8 @@ Patch7: libgcrypt-1.5.0-fips-cavs.patch
 Patch8: libgcrypt-1.5.0-set-enforced-mode.patch
 # fix for memory leaks an other errors found by Coverity scan
 Patch9: libgcrypt-1.5.0-leak.patch
+# allow empty passphrase (upstreamed)
+Patch10: libgcrypt-1.5.0-empty-passphrase.patch
 
 # Technically LGPLv2.1+, but Fedora's table doesn't draw a distinction.
 # Documentation and some utilities are GPLv2+ licensed. These files
@@ -66,6 +68,7 @@ applications using libgcrypt.
 %patch7 -p1 -b .cavs
 %patch8 -p1 -b .enforce
 %patch9 -p1 -b .leak
+%patch10 -p1 -b .emptypass
 
 mv AUTHORS AUTHORS.iso88591
 iconv -f ISO-8859-1 -t UTF-8 AUTHORS.iso88591 >AUTHORS
@@ -179,6 +182,9 @@ exit 0
 %doc COPYING
 
 %changelog
+* Thu Jan  3 2013 Tomas Mraz <tmraz@redhat.com> 1.5.0-9
+- allow empty passphrase in PBKDF2 needed for cryptsetup (=891266)
+
 * Mon Dec  3 2012 Tomas Mraz <tmraz@redhat.com> 1.5.0-8
 - fix multilib conflict in libgcrypt-config
 - fix minor memory leaks and other bugs found by Coverity scan