[LON-CAPA-cvs] cvs: loncom / lonlocal.pm

[foxr]

foxr		Thu Jun 17 05:27:24 2004 EDT

  Modified files:              
    /loncom	lonlocal.pm 
  Log:
  Debug local secure key exchange support
  
  
Index: loncom/lonlocal.pm
diff -u loncom/lonlocal.pm:1.4 loncom/lonlocal.pm:1.5
--- loncom/lonlocal.pm:1.4	Tue Jun  1 05:53:44 2004
+++ loncom/lonlocal.pm	Thu Jun 17 05:27:23 2004
@@ -1,5 +1,5 @@
 #
-# $Id: lonlocal.pm,v 1.4 2004/06/01 09:53:44 foxr Exp $
+# $Id: lonlocal.pm,v 1.5 2004/06/17 09:27:23 foxr Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -56,6 +56,15 @@
 my $lastError;			# Reason for last failure.
 
 
+#  Debugging:
+
+my $DEBUG = 1;
+
+sub Debug {
+    my $msg = shift;
+    print STDERR "$msg\n";
+}
+
 # Initialization
 
 $perlvar = LONCAPA::Configuration::read_conf('loncapa.conf');
@@ -63,7 +72,7 @@
 
 #------------------------------------------------------------------------
 #
-# Name          BuildKey
+# Name          CreateCipherKey
 # Description:  Create an encryption key.
 # Returns:      The key.
 #
@@ -73,13 +82,15 @@
     my $binaryKey;
     my $cipherkey;
     
-    # we'll use the output of /dev/random to produce our key.
+    # we'll use the output of /dev/urandom to produce our key.
     # On a system with decent entropy, this ought to be much more
     # random than all the playing that used to be done to get a key.
-    #
+    # On a system with not so decent entropy we'll still get an ok key.
+    # My concern with /dev/random is that we may block for an indefinite
+    # time period...where for us decent keys are probably good enough.
     
     $keylength   =  IDEA::keysize();
-    open(RANDOM, "</dev/random");
+    open(RANDOM, "</dev/urandom");
     sysread(RANDOM, $binaryKey, $keylength);
     close RANDOM;
     
@@ -111,7 +122,7 @@
     #
     $fileindex++;
     my $CertificateDir = $perlvar->{lonCertificateDirectory};
-    my $Filename       = $CertificateDir.$pathsep.".$fileindex.".$PID;
+    my $Filename       = $CertificateDir.$pathsep.".$fileindex.".$$;
 
     # If this file already exists, this is a recoverable error... we just
     # delete the earlier incarnation of the file.
@@ -134,7 +145,7 @@
     # the file is created with the appropriate locked down permissions.
 
     if(! sysopen(KEYFILE, $Filename, O_CREAT | O_EXCL | O_WRONLY, 0600)) {
-	$lastError = "Creation of key file failed ".$ERRNO;
+	$lastError = "Creation of key file failed ".$!;
 	return undef;
     }
     # Create the key, write it to the file and close the file:
@@ -143,7 +154,7 @@
     print KEYFILE "$key\n";
     close KEYFILE;
 
-    return \($key, $Filename);
+    return ($key, $Filename);
 
     
 }
@@ -165,13 +176,17 @@
 #
 sub ReadKeyFile {
     my $Filename = shift;
+    Debug("ReadKeyFile: $Filename");
+
 
     if(! open(KEYFILE, "<$Filename")) {
+	Debug(" Open of $Filename failed\n");
 	$lastError = "Key file open failed";
 	return undef
     }
     my $key = <KEYFILE>;
-    chomp;
+    chomp($key);
+    Debug(" Read key: $key");
     close KEYFILE;
     unlink $Filename;
     #
@@ -179,6 +194,7 @@
     #  permissions:
     #
     if(-e $Filename) {
+	Debug("File did not get deleted");
 	$lastError = "Key file still exists after unlink";
 	return undef;
     }
@@ -189,9 +205,13 @@
     #  replacing our file... of course if they read this comment they'll
     #  be too smart to put an incorrectly sized file
     #
-    if(length($key) != IDEA::keysize*2) {
+    my $keylen = length($key);
+    my $rightlen= IDEA::keysize()*2;
+    if($keylen != $rightlen) {
+	Debug("Key is incorrect length is $keylen sb $rightlen");
 	$lastError = "Key file has incorrect length";
 	return undef;
     }
+    Debug("Returning key: $key to caller");
     return $key;   
 }