From 399dc2e20b241e772fa16defcc2e2dbe063ac290 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= <ppisar@redhat.com>
Date: Wed, 27 Aug 2014 15:38:54 +0200
Subject: [PATCH] Fix reading IV with new-lines from a file
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Decrypting filehandle data by fh_crypt() could produce bad decrypted
data if the initizalization vector read from the filehandle contained
a new-line character. This caused random failures of 'autogenerating
and autoreading IV should also round-trip' test in t/fh_encrypt.t.

This patch fixes it by reading first 10 characters regardless of
current line separator.

CPAN RT #28370

Signed-off-by: Petr Písař <ppisar@redhat.com>
---
 lib/Crypt/CipherSaber.pm | 14 +++++++++-----
 t/fh_encrypt.t           | 40 +++++++++++++++++++++++++++++++++++++++-
 2 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/lib/Crypt/CipherSaber.pm b/lib/Crypt/CipherSaber.pm
index 7cb7cc0..2db153c 100644
--- a/lib/Crypt/CipherSaber.pm
+++ b/lib/Crypt/CipherSaber.pm
@@ -67,6 +67,15 @@ sub fh_crypt
         $iv = $self->_gen_iv() if length($iv) == 1;
         $self->_setup_key($iv);
         print OUT $iv;
+    } else {
+        if ( 10 != $in->read($iv, 10) )
+        {
+            require Carp;
+            Carp::carp( 'Could not read IV from input filehandle' );
+            return;
+        }
+        ( $iv ) = unpack( "a10", $iv );
+        $self->_setup_key($iv);
     }
 
     my $state = $self->[1];
@@ -75,11 +84,6 @@ sub fh_crypt
 
     while (<$in>)
     {
-        unless ($iv)
-        {
-            ( $iv, $_ ) = unpack( "a10a*", $_ );
-            $self->_setup_key($iv);
-        }
         my $line;
         ( $line, $state, @vars ) = _do_crypt( $state, $_, @vars );
         print OUT $line;
diff --git a/t/fh_encrypt.t b/t/fh_encrypt.t
index 35a74fb..e595ff9 100644
--- a/t/fh_encrypt.t
+++ b/t/fh_encrypt.t
@@ -6,7 +6,7 @@ BEGIN
 }
 
 use strict;
-use Test::More tests => 6;
+use Test::More tests => 7;
 use_ok( 'Crypt::CipherSaber' );
 
 # tests the fh_crypt() method
@@ -114,6 +114,44 @@ while (<SOURCE>)
 
 ok( ! $status, 'autogenerating and autoreading IV should also round-trip' );
 
+# IV retrieved from encrypted file can contain new-line characters. Check that
+# fh_encrypt can deal with it
+{
+	local $/ = "\012";
+
+	open( IN, 'smiles.png' )      or die "Cannot read smiles.png: $!";
+	open( OUT, '> smiles_2.cs1' ) or die "Cannot write to smiles_2.cs1: $!";
+	binmode( IN );
+	binmode( OUT );
+	$cs->fh_crypt( \*IN, \*OUT, $/ x 10 );
+	close IN;
+	close OUT;
+
+	open( IN, 'smiles_2.cs1'    ) or die "Cannot read smiles_2.cs1: $!";
+	open( OUT, '> smiles_2.png' ) or die "Cannot write to smiles_2.png $!";
+	binmode( IN );
+	binmode( OUT );
+	$cs->fh_crypt( \*IN, \*OUT );
+	close IN;
+	close OUT;
+
+	open( SOURCE, 'smiles.png' )   or die "Cannot read smiles.png: $!";
+	open( DEST,   'smiles_2.png' ) or die "Cannot read smiles_2.png: $!";
+	binmode SOURCE;
+	binmode DEST;
+	$status = 0;
+	while (<SOURCE>)
+	{
+		unless ($_ eq <DEST>)
+		{
+			$status = 1;
+			last;
+		}
+	}
+	ok( ! $status, 'IV with new-lines in the encrypted file' );
+}
+
+
 END
 {
 	1 while unlink qw( smiles_2.cs1 smiles_2.png outsmiles.cs1 outsmiles.png );
-- 
2.4.3