Tcl Library Source Code

--- blowfish-1.0.4.tcl	2019-06-06 09:52:21 +0200
+++ blowfish-1.0.5.tcl	2019-06-06 10:02:41 +0200
@@ -509,18 +509,27 @@
     if {[eof $in]} {
         fileevent $in readable {}
         set state(reading) 0
-    }
-
-    set data [read $in $chunksize]
-    # FIX ME: we should ony pad after eof
-    if {[string length $pad] > 0} {
-        set data [Pad $data 8]
-    }
-
-    if {$out == {}} {
-        append state(output) [$state(cmd) $Key $data]
+        set data $state(remainder)
+        # Only pad at the end of the stream.
+        if {[string length $pad] > 0} {
+            set data [Pad $data 8 $pad]
+        }
     } else {
-        puts -nonewline $out [$state(cmd) $Key $data]
+        set data [read $in $chunksize]
+        puts "Chunk: reading [string len $data] bytes"
+        set data $state(remainder)$data
+        # If data is not a multiple of 8, state(remainder) will hold
+        # excess bytes for the next round.
+        set pagedlen [expr {([string length $data] / 8) * 8}]
+        set state(remainder) [string range $data $pagedlen end]
+        set data [string range $data 0 $pagedlen-1]
+    }
+    if {[string length $data] > 0} {
+        if {$out == {}} {
+            append state(output) [$state(cmd) $Key $data]
+        } else {
+            puts -nonewline $out [$state(cmd) $Key $data]
+        }
     }
 }
 
@@ -585,7 +594,7 @@
 proc ::blowfish::Pad {data blocksize {fill \0}} {
     set len [string length $data]
     if {$len == 0} {
-        set data [string repeat $fill $blocksize]
+        # do not pad an empty string
     } elseif {($len % $blocksize) != 0} {
         set pad [expr {$blocksize - ($len % $blocksize)}]
         append data [string repeat $fill $pad]
@@ -682,6 +691,7 @@
             set state(cmd) Decrypt
         }
         set state(output) ""
+        set state(remainder) ""
         fileevent $opts(-in) readable \
             [list [namespace origin Chunk] \
                  $Key $opts(-in) $opts(-out) $opts(-chunksize) $opts(-pad)]