Add sunshar, a "secure unshar" for ports committers, which:

  - Does not execute unknown commands nor call sh(1) at all.
  - Does not overwrite existing files by default.
  - Does not extract files into upper directories.
  - Does have a dry run (-n) flag to see what would have been extracted.
  - Does have a strip (-p N) flag to strip any number of levels from
    pathnames.

It (so far) only supports shell archives made with BSD shar.

3 files changed, 368 insertions, 0 deletions

diff --git a/Tools/scripts/sunshar.rb b/Tools/scripts/sunshar.rb
new file mode 100755
index 0000000..70b038e
--- /dev/null
+++ b/Tools/scripts/sunshar.rb
@@ -0,0 +1,299 @@
+#!/usr/bin/env ruby
+# -*- ruby -*-
+#
+# Copyright (c) 2001-2004 Akinori MUSHA
+#
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+# $FreeBSD$
+
+RCS_ID = %q$Idaemons: /home/cvs/sunshar/sunshar.rb,v 1.13 2004/02/28 14:15:47 knu Exp $
+RCS_REVISION = RCS_ID.split[2]
+MYNAME = File.basename($0)
+
+require 'parsearg'
+require 'fileutils'
+require 'shellwords'
+require 'stringio'
+
+begin
+  require 'features/ruby18/dir'
+rescue LoadError; end
+
+$USAGE = 'usage'
+
+$strip_level = 0
+$force = false
+$dryrun = false
+$quiet = false
+$dir = nil
+
+def info(*s)
+  puts(*s) unless $quiet
+end
+
+def usage
+  print <<-EOF
+#{MYNAME} rev.#{RCS_REVISION}
+
+usage:  #{MYNAME} [-fnq] [-p level] [file]
+        #{MYNAME} -h
+  -d dir  chdir   -- chdir to dir before extracting files
+  -f      force   -- allow overwriting, ignore errors
+  -h      help    -- show this help
+  -n      dry run -- show what would have been extracted
+  -p N    strip   -- strip N levels from pathnames (cf. patch(1)\'s -p)
+  -q      quiet   -- be quiet
+  EOF
+end
+
+def main
+  parseArgs(0, nil, 'fhnq', 'd:', 'p:')
+
+  if $OPT_h
+    usage
+    exit 0
+  end
+
+  if $OPT_f
+    $force = true
+  end
+
+  if $OPT_n
+    $dryrun = true
+  end
+
+  if $OPT_q
+    $quiet = true
+  end
+
+  $dir = $OPT_d || '.'
+
+  if $OPT_p
+    $strip_level = $OPT_p.to_i rescue -1
+
+    if $strip_level < 0
+      STDERR.puts "negative value ignored: #{$OPT_p}"
+    end
+  end
+
+  nerrors = 0
+
+  if ARGV.empty?
+    info "extracting files from stdin into #{$dir}"
+
+    begin
+      Dir.chdir($dir) {
+	unshar_stream(STDIN)
+      }
+
+      info "done."
+    rescue => e
+      STDERR.puts "error in extracting stdin: #{e.message}"
+      nerrors += 1
+    end
+  else
+    for file in ARGV
+      info "extracting files from #{file} into #{$dir}"
+
+      begin
+	File.open(file) do |f|
+	  Dir.chdir($dir) {
+	    unshar_stream(f)
+	  }
+	end
+
+	info "done."
+      rescue => e
+	STDERR.puts "error in extracting #{file}: #{e.message}"
+	nerrors += 1
+      end
+    end
+  end
+
+  exit nerrors
+end
+
+def unshar_stream(io)
+  e = nil
+
+  while line = io.gets
+    if /^(\s*)\# This is a shell archive/ =~ line
+      indent = $1.length
+      break
+    end
+  end
+
+  if io.eof?
+    raise "not a shell archive."
+  end
+
+  f = nil
+  prefix = nil
+  file = nil
+  boundary = nil
+
+  while line = io.gets
+    line.slice!(0, indent)
+
+    if f
+      if line.strip == boundary
+	f.close
+	f = nil
+	next
+      end
+
+      if line.sub!(/^#{Regexp.quote(prefix)}/, '')
+	f.print line
+      else
+	raise "line #{io.lineno}: broken archive: #{line}"
+      end
+
+      next
+    end
+
+    case line
+    when /^exit\s*$/
+      break
+    when /^echo\s+(.+)$/
+      # info $1
+    when /^mkdir\s+(?:-p\s+)?(.+)$/
+      dir = nil
+
+      Shellwords.shellwords($1).each do |word|
+	if /^[^\-]/ =~ word
+	  dir = word
+	  break
+	end
+      end
+
+      next if dir.nil?
+
+      dir = strip_filename(dir.strip + '/')
+      if dir.chomp('/').empty?
+	next
+      end
+
+      begin
+	FileUtils.mkdir_p(dir) unless $dryrun
+	info "c - #{dir}"
+      rescue => e
+	info "c - #{dir} ... failed: #{e.message}"
+	raise e
+      end
+    when /sed\s+(.+)>(.+)<<(.+)/
+      prefix = Shellwords.shellwords($1).first
+      file = Shellwords.shellwords($2).first
+      boundary = Shellwords.shellwords($3).first
+
+      next unless prefix && file && boundary
+
+      if /s(.)\^(.*)\1\1/ =~ prefix
+	prefix = $2
+      else
+	next
+      end
+
+      file = strip_filename(file)
+
+      next if file.empty? || boundary.empty?
+
+      overwrite = false
+
+      if File.exist?(file)
+	if $force
+	  overwrite = true
+	else
+	  info "x - #{file} ... skipped"
+	  next
+	end
+      end
+
+      dir = File.dirname(file)
+
+      if !File.directory?(dir + "/.")
+	begin
+	  FileUtils.mkdir_p(dir) unless $dryrun
+	  info "d - #{dir}"
+	rescue => e
+	  info "d - #{dir} ... failed: #{e.message}"
+	  raise e
+	end
+      end
+
+      begin
+        f = $dryrun ? StringIO.new : File.open(file, 'w')
+	if overwrite
+	  info "x - #{file} ... overwritten"
+	else
+	  info "x - #{file}"
+	end
+      rescue => e
+	info "x - #{file} ... failed! (#{e.message})"
+
+	if $force
+	  f = nil
+	  next
+	else
+	  raise e
+	end
+      end
+    end
+  end
+
+  raise e if e
+end
+
+def strip_filename(file)
+  sfile = file.gsub(%r"/{2,}", "/")
+
+  if 0 < $strip_level
+    sfile.sub!(%r"^([^/]*/){1,#{$strip_level}}", '')
+  end
+
+  case sfile
+  when %r"^[~/]"
+    raise "reference to absolute directory: #{file} (use -p N)"
+  when %r"(^|/)\.\.(?:/|$)"
+    raise "reference to parent directory: #{file} (use -p N)"
+  end
+
+  sfile
+end
+
+def signal_handler(sig)
+  info "\nInterrupted."
+
+  exit 255
+end
+
+if $0 == __FILE__
+  for sig in [2, 3, 15]
+    trap(sig) do
+      signal_handler(sig)
+    end
+  end
+
+  main
+end
diff --git a/Tools/scripts/sunshar/Makefile b/Tools/scripts/sunshar/Makefile
new file mode 100644
index 0000000..581e717
--- /dev/null
+++ b/Tools/scripts/sunshar/Makefile
@@ -0,0 +1,13 @@
+# $FreeBSD$
+# $Idaemons: /home/cvs/sunshar/Makefile,v 1.1.1.1 2001/09/09 13:49:08 knu Exp $
+
+PREFIX?=	/usr/local
+BINDIR=		${PREFIX}/bin
+MANDIR=		${PREFIX}/man/man
+
+SCRIPTS=	sunshar.rb
+MAN=		sunshar.1
+
+.PATH:	${.CURDIR}/..
+
+.include <bsd.prog.mk>
diff --git a/Tools/scripts/sunshar/sunshar.1 b/Tools/scripts/sunshar/sunshar.1
new file mode 100644
index 0000000..ee24f22
--- /dev/null
+++ b/Tools/scripts/sunshar/sunshar.1
@@ -0,0 +1,56 @@
+.\" $FreeBSD$
+.\" $Idaemons: /home/cvs/sunshar/sunshar.1,v 1.2 2004/02/28 14:14:53 knu Exp $
+.\"
+.Dd September 9, 2001
+.Dt SUNSHAR 1
+.Os FreeBSD
+.Sh NAME
+.Nm sunshar
+.Nd a secure unshar
+.Sh SYNOPSIS
+.Nm
+.Op Fl hfnq
+.Op Fl p Ar number
+.Op Ar file ...
+.Sh DESCRIPTION
+The
+.Nm
+command extracts files from the given shell archive(s).  If no file
+name is given, it reads from the standard input.
+.Pp
+It brings you security because it never executes dangerous commands
+possibly contained in a shell archive.  Also, it does not overwrite
+existing files unless the
+.Fl f
+option is specified.
+.Sh OPTIONS
+The following command line arguments are supported:
+.Pp
+.Bl -tag -width "-p number" -compact
+.It Fl h
+Show help and exit.
+.Pp
+.It Fl f
+Allow overwriting existing files, and ignore errors and continue.
+.Pp
+.It Fl p Ar number
+Strip
+.Ar number
+levels of path components from path names. (cf.
+.Xr patch 1 's
+.Fl p
+option)
+.Pp
+.It Fl n
+Do not extract anything but just show what would have been extracted.
+.Pp
+.It Fl q
+Be quiet.
+.El
+.Sh SEE ALSO
+.Xr shar 1
+.Sh AUTHORS
+.An Akinori MUSHA Aq knu@iDaemons.org
+.Sh BUGS
+.Nm
+only supports shell archives made with BSD shar.