[Pymoul-svn] SF.net SVN: pymoul: [210] xtea

[<ti...@us...>]

Revision: 210
          http://pymoul.svn.sourceforge.net/pymoul/?rev=210&view=rev
Author:   tiran
Date:     2007-02-27 08:22:39 -0800 (Tue, 27 Feb 2007)

Log Message:
-----------
Initial import of xtea module

Added Paths:
-----------
    xtea/
    xtea/branches/
    xtea/tags/
    xtea/trunk/
    xtea/trunk/CHANGES.txt
    xtea/trunk/INSTALL.txt
    xtea/trunk/LICENSE.txt
    xtea/trunk/MANIFEST.in
    xtea/trunk/Makefile
    xtea/trunk/README.txt
    xtea/trunk/ez_setup.py
    xtea/trunk/setup.py
    xtea/trunk/src/
    xtea/trunk/src/xtea.egg-info/
    xtea/trunk/src/xtea.egg-info/PKG-INFO
    xtea/trunk/src/xtea.egg-info/SOURCES.txt
    xtea/trunk/src/xtea.egg-info/dependency_links.txt
    xtea/trunk/src/xtea.egg-info/top_level.txt
    xtea/trunk/src/xtea.egg-info/zip-safe
    xtea/trunk/src/xtea.py
    xtea/trunk/version.txt

Added: xtea/trunk/CHANGES.txt
===================================================================


Property changes on: xtea/trunk/CHANGES.txt
___________________________________________________________________
Name: svn:keywords
   + 'Id Revision'
Name: svn:eol-style
   + native

Added: xtea/trunk/INSTALL.txt
===================================================================
--- xtea/trunk/INSTALL.txt	                        (rev 0)
+++ xtea/trunk/INSTALL.txt	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1,13 @@
+============
+Requirements
+============
+
+ * Python 2.4+ http://www.python.org/
+ * easy_install http://peak.telecommunity.com/DevCenter/EasyInstall
+ * setuptools (via easy install) 
+
+============
+Installation
+============
+
+ $ python setup.py install


Property changes on: xtea/trunk/INSTALL.txt
___________________________________________________________________
Name: svn:keywords
   + 'Id Revision'
Name: svn:eol-style
   + native

Added: xtea/trunk/LICENSE.txt
===================================================================
--- xtea/trunk/LICENSE.txt	                        (rev 0)
+++ xtea/trunk/LICENSE.txt	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1 @@
+Public Domain
\ No newline at end of file


Property changes on: xtea/trunk/LICENSE.txt
___________________________________________________________________
Name: svn:keywords
   + 'Id Revision'
Name: svn:eol-style
   + native

Added: xtea/trunk/MANIFEST.in
===================================================================
--- xtea/trunk/MANIFEST.in	                        (rev 0)
+++ xtea/trunk/MANIFEST.in	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1,4 @@
+include *.txt setup.py ez_setup.py Makefile
+include src/xtea.py
+
+

Added: xtea/trunk/Makefile
===================================================================
--- xtea/trunk/Makefile	                        (rev 0)
+++ xtea/trunk/Makefile	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1,54 @@
+PYTHON?=python2.5
+PYTHON24=python2.4
+PYTHON25=python2.5
+TESTFLAGS=-v
+TESTOPTS=
+SETUPFLAGS=
+KEYID=AD16AB1B
+
+all: inplace
+
+# Build in-place
+inplace:
+	$(PYTHON) setup.py $(SETUPFLAGS) build_ext -i
+
+build:
+	$(PYTHON) setup.py $(SETUPFLAGS) build
+
+egg24:
+	$(PYTHON24) setup.py $(SETUPFLAGS) bdist_egg
+
+egg25:
+	$(PYTHON25) setup.py $(SETUPFLAGS) bdist_egg
+
+dist25:
+	$(PYTHON25) setup.py $(SETUPFLAGS) bdist_egg \
+	    sdist --formats=zip,gztar
+
+dist_upload: realclean
+	$(PYTHON25) setup.py $(SETUPFLAGS) bdist_egg \
+	    sdist --formats=zip,gztar \
+	    upload --sign --identity=$(KEYID)
+
+# What should the default be?
+test:
+	$(PYTHON) xtea.py
+
+egg: egg24 egg25
+
+distribution: realclean dist25 egg24 gpg
+
+gpg:
+	for F in `find dist -type f -and -not -name '*.asc'`; do \
+	    gpg --detach-sign --armor --default-key $(KEYID) $$F; \
+	done
+	md5sum dist/*.zip dist/*.egg dist/*.gz
+
+clean:
+	find . \( -name '*.o' -o -name '*~' -o -name '*.so' -o -name '*.py[cod]' -o -name '*.dll' \) -exec rm -f {} \;
+	rm -rf build
+
+realclean: clean
+	rm -f TAGS
+	rm -rf dist
+	$(PYTHON) setup.py clean -a


Property changes on: xtea/trunk/Makefile
___________________________________________________________________
Name: svn:keywords
   + 'Id Revision'
Name: svn:eol-style
   + native

Added: xtea/trunk/README.txt
===================================================================
--- xtea/trunk/README.txt	                        (rev 0)
+++ xtea/trunk/README.txt	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1,28 @@
+XTEA Block Encryption Algorithm
+
+Author: Paul Chakravarti (paul_dot_chakravarti_at_mac_dot_com)
+License: Public Domain
+
+This module provides a Python implementation of the XTEA block encryption
+algorithm (http://www.cix.co.uk/~klockstone/xtea.pdf). 
+
+The module implements the basic XTEA block encryption algortithm
+(`xtea_encrypt`/`xtea_decrypt`) and also provides a higher level `crypt`
+function which symmetrically encrypts/decrypts a variable length string using
+XTEA in OFB mode as a key generator. The `crypt` function does not use
+`xtea_decrypt` which is provided for completeness only (but can be used
+to support other stream modes - eg CBC/CFB).
+
+This module is intended to provide a simple 'privacy-grade' Python encryption
+algorithm with no external dependencies. The implementation is relatively slow
+and is best suited to small volumes of data. Note that the XTEA algorithm has
+not been subjected to extensive analysis (though is believed to be relatively
+secure - see http://en.wikipedia.org/wiki/XTEA). For applications requiring
+'real' security please use a known and well tested algorithm/implementation.
+
+The security of the algorithm is entirely based on quality (entropy) and
+secrecy of the key. You should generate the key from a known random source and
+exchange using a trusted mechanism. In addition, you should always use a random
+IV to seed the key generator (the IV is not sensitive and does not need to be
+exchanged securely)
+


Property changes on: xtea/trunk/README.txt
___________________________________________________________________
Name: svn:keywords
   + 'Id Revision'
Name: svn:eol-style
   + native

Added: xtea/trunk/ez_setup.py
===================================================================
--- xtea/trunk/ez_setup.py	                        (rev 0)
+++ xtea/trunk/ez_setup.py	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1,228 @@
+#!python
+"""Bootstrap setuptools installation
+
+If you want to use setuptools in your package's setup.py, just include this
+file in the same directory with it, and add this to the top of your setup.py::
+
+    from ez_setup import use_setuptools
+    use_setuptools()
+
+If you want to require a specific version of setuptools, set a download
+mirror, or use an alternate download directory, you can do so by supplying
+the appropriate options to ``use_setuptools()``.
+
+This file can also be run as a script to install or upgrade setuptools.
+"""
+import sys
+DEFAULT_VERSION = "0.6c5"
+DEFAULT_URL     = "http://cheeseshop.python.org/packages/%s/s/setuptools/" % sys.version[:3]
+
+md5_data = {
+    'setuptools-0.6b1-py2.3.egg': '8822caf901250d848b996b7f25c6e6ca',
+    'setuptools-0.6b1-py2.4.egg': 'b79a8a403e4502fbb85ee3f1941735cb',
+    'setuptools-0.6b2-py2.3.egg': '5657759d8a6d8fc44070a9d07272d99b',
+    'setuptools-0.6b2-py2.4.egg': '4996a8d169d2be661fa32a6e52e4f82a',
+    'setuptools-0.6b3-py2.3.egg': 'bb31c0fc7399a63579975cad9f5a0618',
+    'setuptools-0.6b3-py2.4.egg': '38a8c6b3d6ecd22247f179f7da669fac',
+    'setuptools-0.6b4-py2.3.egg': '62045a24ed4e1ebc77fe039aa4e6f7e5',
+    'setuptools-0.6b4-py2.4.egg': '4cb2a185d228dacffb2d17f103b3b1c4',
+    'setuptools-0.6c1-py2.3.egg': 'b3f2b5539d65cb7f74ad79127f1a908c',
+    'setuptools-0.6c1-py2.4.egg': 'b45adeda0667d2d2ffe14009364f2a4b',
+    'setuptools-0.6c2-py2.3.egg': 'f0064bf6aa2b7d0f3ba0b43f20817c27',
+    'setuptools-0.6c2-py2.4.egg': '616192eec35f47e8ea16cd6a122b7277',
+    'setuptools-0.6c3-py2.3.egg': 'f181fa125dfe85a259c9cd6f1d7b78fa',
+    'setuptools-0.6c3-py2.4.egg': 'e0ed74682c998bfb73bf803a50e7b71e',
+    'setuptools-0.6c3-py2.5.egg': 'abef16fdd61955514841c7c6bd98965e',
+    'setuptools-0.6c4-py2.3.egg': 'b0b9131acab32022bfac7f44c5d7971f',
+    'setuptools-0.6c4-py2.4.egg': '2a1f9656d4fbf3c97bf946c0a124e6e2',
+    'setuptools-0.6c4-py2.5.egg': '8f5a052e32cdb9c72bcf4b5526f28afc',
+    'setuptools-0.6c5-py2.3.egg': 'ee9fd80965da04f2f3e6b3576e9d8167',
+    'setuptools-0.6c5-py2.4.egg': 'afe2adf1c01701ee841761f5bcd8aa64',
+    'setuptools-0.6c5-py2.5.egg': 'a8d3f61494ccaa8714dfed37bccd3d5d',
+}
+
+import sys, os
+
+def _validate_md5(egg_name, data):
+    if egg_name in md5_data:
+        from md5 import md5
+        digest = md5(data).hexdigest()
+        if digest != md5_data[egg_name]:
+            print >>sys.stderr, (
+                "md5 validation of %s failed!  (Possible download problem?)"
+                % egg_name
+            )
+            sys.exit(2)
+    return data
+
+
+def use_setuptools(
+    version=DEFAULT_VERSION, download_base=DEFAULT_URL, to_dir=os.curdir,
+    download_delay=15
+):
+    """Automatically find/download setuptools and make it available on sys.path
+
+    `version` should be a valid setuptools version number that is available
+    as an egg for download under the `download_base` URL (which should end with
+    a '/').  `to_dir` is the directory where setuptools will be downloaded, if
+    it is not already available.  If `download_delay` is specified, it should
+    be the number of seconds that will be paused before initiating a download,
+    should one be required.  If an older version of setuptools is installed,
+    this routine will print a message to ``sys.stderr`` and raise SystemExit in
+    an attempt to abort the calling script.
+    """
+    try:
+        import setuptools
+        if setuptools.__version__ == '0.0.1':
+            print >>sys.stderr, (
+            "You have an obsolete version of setuptools installed.  Please\n"
+            "remove it from your system entirely before rerunning this script."
+            )
+            sys.exit(2)
+    except ImportError:
+        egg = download_setuptools(version, download_base, to_dir, download_delay)
+        sys.path.insert(0, egg)
+        import setuptools; setuptools.bootstrap_install_from = egg
+
+    import pkg_resources
+    try:
+        pkg_resources.require("setuptools>="+version)
+
+    except pkg_resources.VersionConflict, e:
+        # XXX could we install in a subprocess here?
+        print >>sys.stderr, (
+            "The required version of setuptools (>=%s) is not available, and\n"
+            "can't be installed while this script is running. Please install\n"
+            " a more recent version first.\n\n(Currently using %r)"
+        ) % (version, e.args[0])
+        sys.exit(2)
+
+def download_setuptools(
+    version=DEFAULT_VERSION, download_base=DEFAULT_URL, to_dir=os.curdir,
+    delay = 15
+):
+    """Download setuptools from a specified location and return its filename
+
+    `version` should be a valid setuptools version number that is available
+    as an egg for download under the `download_base` URL (which should end
+    with a '/'). `to_dir` is the directory where the egg will be downloaded.
+    `delay` is the number of seconds to pause before an actual download attempt.
+    """
+    import urllib2, shutil
+    egg_name = "setuptools-%s-py%s.egg" % (version,sys.version[:3])
+    url = download_base + egg_name
+    saveto = os.path.join(to_dir, egg_name)
+    src = dst = None
+    if not os.path.exists(saveto):  # Avoid repeated downloads
+        try:
+            from distutils import log
+            if delay:
+                log.warn("""
+---------------------------------------------------------------------------
+This script requires setuptools version %s to run (even to display
+help).  I will attempt to download it for you (from
+%s), but
+you may need to enable firewall access for this script first.
+I will start the download in %d seconds.
+
+(Note: if this machine does not have network access, please obtain the file
+
+   %s
+
+and place it in this directory before rerunning this script.)
+---------------------------------------------------------------------------""",
+                    version, download_base, delay, url
+                ); from time import sleep; sleep(delay)
+            log.warn("Downloading %s", url)
+            src = urllib2.urlopen(url)
+            # Read/write all in one block, so we don't create a corrupt file
+            # if the download is interrupted.
+            data = _validate_md5(egg_name, src.read())
+            dst = open(saveto,"wb"); dst.write(data)
+        finally:
+            if src: src.close()
+            if dst: dst.close()
+    return os.path.realpath(saveto)
+
+def main(argv, version=DEFAULT_VERSION):
+    """Install or upgrade setuptools and EasyInstall"""
+
+    try:
+        import setuptools
+    except ImportError:
+        egg = None
+        try:
+            egg = download_setuptools(version, delay=0)
+            sys.path.insert(0,egg)
+            from setuptools.command.easy_install import main
+            return main(list(argv)+[egg])   # we're done here
+        finally:
+            if egg and os.path.exists(egg):
+                os.unlink(egg)
+    else:
+        if setuptools.__version__ == '0.0.1':
+            # tell the user to uninstall obsolete version
+            use_setuptools(version)
+
+    req = "setuptools>="+version
+    import pkg_resources
+    try:
+        pkg_resources.require(req)
+    except pkg_resources.VersionConflict:
+        try:
+            from setuptools.command.easy_install import main
+        except ImportError:
+            from easy_install import main
+        main(list(argv)+[download_setuptools(delay=0)])
+        sys.exit(0) # try to force an exit
+    else:
+        if argv:
+            from setuptools.command.easy_install import main
+            main(argv)
+        else:
+            print "Setuptools version",version,"or greater has been installed."
+            print '(Run "ez_setup.py -U setuptools" to reinstall or upgrade.)'
+
+
+
+def update_md5(filenames):
+    """Update our built-in md5 registry"""
+
+    import re
+    from md5 import md5
+
+    for name in filenames:
+        base = os.path.basename(name)
+        f = open(name,'rb')
+        md5_data[base] = md5(f.read()).hexdigest()
+        f.close()
+
+    data = ["    %r: %r,\n" % it for it in md5_data.items()]
+    data.sort()
+    repl = "".join(data)
+
+    import inspect
+    srcfile = inspect.getsourcefile(sys.modules[__name__])
+    f = open(srcfile, 'rb'); src = f.read(); f.close()
+
+    match = re.search("\nmd5_data = {\n([^}]+)}", src)
+    if not match:
+        print >>sys.stderr, "Internal error!"
+        sys.exit(2)
+
+    src = src[:match.start(1)] + repl + src[match.end(1):]
+    f = open(srcfile,'w')
+    f.write(src)
+    f.close()
+
+
+if __name__=='__main__':
+    if len(sys.argv)>2 and sys.argv[1]=='--md5update':
+        update_md5(sys.argv[2:])
+    else:
+        main(sys.argv[1:])
+
+
+
+
+


Property changes on: xtea/trunk/ez_setup.py
___________________________________________________________________
Name: svn:executable
   + 
Name: svn:keywords
   + 'Id Revision'
Name: svn:eol-style
   + native

Added: xtea/trunk/setup.py
===================================================================
--- xtea/trunk/setup.py	                        (rev 0)
+++ xtea/trunk/setup.py	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1,71 @@
+#!/usr/bin/env python
+"""XTEA Block Encryption Algorithm
+
+This module provides a Python implementation of the XTEA block encryption
+algorithm (http://www.cix.co.uk/~klockstone/xtea.pdf). 
+
+The module implements the basic XTEA block encryption algortithm
+(`xtea_encrypt`/`xtea_decrypt`) and also provides a higher level `crypt`
+function which symmetrically encrypts/decrypts a variable length string using
+XTEA in OFB mode as a key generator. The `crypt` function does not use
+`xtea_decrypt` which is provided for completeness only (but can be used
+to support other stream modes - eg CBC/CFB).
+"""
+__author__ = "Christian Heimes"
+__version__ = "$Id: setup.py 203 2007-02-27 14:31:27Z tiran $"
+__revision__ = "$Revision: 203 $"
+
+import sys
+
+if sys.version_info < (2,4):
+    raise RuntimeError("Python 2.4+ required:\n%s" % sys.version)
+
+# boot strap easy setup
+SETUPTOOLS_VERSION = "0.6c1"
+from ez_setup import use_setuptools
+use_setuptools(version=SETUPTOOLS_VERSION)
+
+# import the rest
+from setuptools import setup
+from setuptools import find_packages
+
+from distutils.core import setup
+
+VERSION = "1.0"
+
+me = "Christian Heimes"
+email = "chr...@ch..."
+
+setup_infos = dict(
+    name = "xtea",
+    version = VERSION,
+    description = __doc__[:__doc__.find('\n')].strip(),
+    long_description = '\n'.join([line
+                                  for line in __doc__.split('\n')[1:]]),
+    author = "Paul Chakravarti",
+    author_email = "paul_dot_chakravarti_at_mac_dot_com",
+    maintainer = "Christian Heimes",
+    maintainer_email = "chr...@ch...",
+    url = "http://sourceforge.net/projects/pymoul/",
+    download_url= "http://cheeseshop.python.org/pypi/",
+    license = "Public Domain",
+    keywords = ["xtea", "crypt", "encryption", "decryption"],
+    platforms = ['Independent'],
+    classifiers = (
+        'Development Status :: 6 - Mature',
+        'Intended Audience :: Developers',
+        'License :: Public Domain',
+	'Operating System :: OS Independent'
+        'Natural Language :: English',
+        'Programming Language :: Python',
+        'Topic :: Software Development :: Libraries'
+    ),
+    setup_requires = ["setuptools>="+SETUPTOOLS_VERSION,],
+    #packages = ['xtea'],
+    py_modules = ['xtea'],
+    package_dir = {'' : 'src'},
+    zip_safe = True,
+)
+
+setup(**setup_infos)
+


Property changes on: xtea/trunk/setup.py
___________________________________________________________________
Name: svn:executable
   + 
Name: svn:keywords
   + 'Id Revision'
Name: svn:eol-style
   + native

Added: xtea/trunk/src/xtea.egg-info/PKG-INFO
===================================================================
--- xtea/trunk/src/xtea.egg-info/PKG-INFO	                        (rev 0)
+++ xtea/trunk/src/xtea.egg-info/PKG-INFO	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1,28 @@
+Metadata-Version: 1.0
+Name: xtea
+Version: 1.0
+Summary: XTEA Block Encryption Algorithm
+Home-page: http://sourceforge.net/projects/pymoul/
+Author: Christian Heimes
+Author-email: chr...@ch...
+License: Public Domain
+Download-URL: http://cheeseshop.python.org/pypi/
+Description: 
+        This module provides a Python implementation of the XTEA block encryption
+        algorithm (http://www.cix.co.uk/~klockstone/xtea.pdf).
+        
+        The module implements the basic XTEA block encryption algortithm
+        (`xtea_encrypt`/`xtea_decrypt`) and also provides a higher level `crypt`
+        function which symmetrically encrypts/decrypts a variable length string using
+        XTEA in OFB mode as a key generator. The `crypt` function does not use
+        `xtea_decrypt` which is provided for completeness only (but can be used
+        to support other stream modes - eg CBC/CFB).
+        
+Keywords: xtea,crypt,encryption,decryption
+Platform: Independent
+Classifier: Development Status :: 6 - Mature
+Classifier: Intended Audience :: Developers
+Classifier: License :: Public Domain
+Classifier: Operating System :: OS IndependentNatural Language :: English
+Classifier: Programming Language :: Python
+Classifier: Topic :: Software Development :: Libraries

Added: xtea/trunk/src/xtea.egg-info/SOURCES.txt
===================================================================
--- xtea/trunk/src/xtea.egg-info/SOURCES.txt	                        (rev 0)
+++ xtea/trunk/src/xtea.egg-info/SOURCES.txt	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1,15 @@
+CHANGES.txt
+INSTALL.txt
+LICENSE.txt
+MANIFEST.in
+Makefile
+README.txt
+ez_setup.py
+setup.py
+version.txt
+src/xtea.py
+src/xtea.egg-info/PKG-INFO
+src/xtea.egg-info/SOURCES.txt
+src/xtea.egg-info/dependency_links.txt
+src/xtea.egg-info/top_level.txt
+src/xtea.egg-info/zip-safe


Property changes on: xtea/trunk/src/xtea.egg-info/SOURCES.txt
___________________________________________________________________
Name: svn:keywords
   + 'Id Revision'
Name: svn:eol-style
   + native

Added: xtea/trunk/src/xtea.egg-info/dependency_links.txt
===================================================================
--- xtea/trunk/src/xtea.egg-info/dependency_links.txt	                        (rev 0)
+++ xtea/trunk/src/xtea.egg-info/dependency_links.txt	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1 @@
+


Property changes on: xtea/trunk/src/xtea.egg-info/dependency_links.txt
___________________________________________________________________
Name: svn:keywords
   + 'Id Revision'
Name: svn:eol-style
   + native

Added: xtea/trunk/src/xtea.egg-info/top_level.txt
===================================================================
--- xtea/trunk/src/xtea.egg-info/top_level.txt	                        (rev 0)
+++ xtea/trunk/src/xtea.egg-info/top_level.txt	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1 @@
+xtea


Property changes on: xtea/trunk/src/xtea.egg-info/top_level.txt
___________________________________________________________________
Name: svn:keywords
   + 'Id Revision'
Name: svn:eol-style
   + native

Added: xtea/trunk/src/xtea.egg-info/zip-safe
===================================================================
--- xtea/trunk/src/xtea.egg-info/zip-safe	                        (rev 0)
+++ xtea/trunk/src/xtea.egg-info/zip-safe	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1 @@
+

Added: xtea/trunk/src/xtea.py
===================================================================
--- xtea/trunk/src/xtea.py	                        (rev 0)
+++ xtea/trunk/src/xtea.py	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1,128 @@
+""" 
+XTEA Block Encryption Algorithm
+
+Author: Paul Chakravarti (paul_dot_chakravarti_at_mac_dot_com)
+License: Public Domain
+
+This module provides a Python implementation of the XTEA block encryption
+algorithm (http://www.cix.co.uk/~klockstone/xtea.pdf). 
+
+The module implements the basic XTEA block encryption algortithm
+(`xtea_encrypt`/`xtea_decrypt`) and also provides a higher level `crypt`
+function which symmetrically encrypts/decrypts a variable length string using
+XTEA in OFB mode as a key generator. The `crypt` function does not use
+`xtea_decrypt` which is provided for completeness only (but can be used
+to support other stream modes - eg CBC/CFB).
+
+This module is intended to provide a simple 'privacy-grade' Python encryption
+algorithm with no external dependencies. The implementation is relatively slow
+and is best suited to small volumes of data. Note that the XTEA algorithm has
+not been subjected to extensive analysis (though is believed to be relatively
+secure - see http://en.wikipedia.org/wiki/XTEA). For applications requiring
+'real' security please use a known and well tested algorithm/implementation.
+
+The security of the algorithm is entirely based on quality (entropy) and
+secrecy of the key. You should generate the key from a known random source and
+exchange using a trusted mechanism. In addition, you should always use a random
+IV to seed the key generator (the IV is not sensitive and does not need to be
+exchanged securely)
+
+    >>> import os
+    >>> iv = 'ABCDEFGH'
+    >>> z = crypt('0123456789012345','Hello There',iv)
+    >>> z.encode('hex')
+    'fe196d0a40d6c222b9eff3'
+    >>> crypt('0123456789012345',z,iv)
+    'Hello There'
+
+""" 
+
+import struct
+
+def crypt(key,data,iv='\00\00\00\00\00\00\00\00',n=32):
+    """
+        Encrypt/decrypt variable length string using XTEA cypher as
+        key generator (OFB mode)
+        * key = 128 bit (16 char) 
+        * iv = 64 bit (8 char)
+        * data = string (any length)
+
+        >>> import os
+        >>> key = os.urandom(16)
+        >>> iv = os.urandom(8)
+        >>> data = os.urandom(10000)
+        >>> z = crypt(key,data,iv)
+        >>> crypt(key,z,iv) == data
+        True
+
+    """
+    def keygen(key,iv,n):
+        while True:
+            iv = xtea_encrypt(key,iv,n)
+            for k in iv:
+                yield ord(k)
+    xor = [ chr(x^y) for (x,y) in zip(map(ord,data),keygen(key,iv,n)) ]
+    return "".join(xor)
+
+def xtea_encrypt(key,block,n=32,endian="!"):
+    """
+        Encrypt 64 bit data block using XTEA block cypher
+        * key = 128 bit (16 char) 
+        * block = 64 bit (8 char)
+        * n = rounds (default 32)
+        * endian = byte order (see 'struct' doc - default big/network) 
+
+        >>> z = xtea_encrypt('0123456789012345','ABCDEFGH')
+        >>> z.encode('hex')
+        'b67c01662ff6964a'
+
+        Only need to change byte order if sending/receiving from 
+        alternative endian implementation 
+
+        >>> z = xtea_encrypt('0123456789012345','ABCDEFGH',endian="<")
+        >>> z.encode('hex')
+        'ea0c3d7c1c22557f'
+
+    """
+    v0,v1 = struct.unpack(endian+"2L",block)
+    k = struct.unpack(endian+"4L",key)
+    sum,delta,mask = 0L,0x9e3779b9L,0xffffffffL
+    for round in range(n):
+        v0 = (v0 + (((v1<<4 ^ v1>>5) + v1) ^ (sum + k[sum & 3]))) & mask
+        sum = (sum + delta) & mask
+        v1 = (v1 + (((v0<<4 ^ v0>>5) + v0) ^ (sum + k[sum>>11 & 3]))) & mask
+    return struct.pack(endian+"2L",v0,v1)
+
+def xtea_decrypt(key,block,n=32,endian="!"):
+    """
+        Decrypt 64 bit data block using XTEA block cypher
+        * key = 128 bit (16 char) 
+        * block = 64 bit (8 char)
+        * n = rounds (default 32)
+        * endian = byte order (see 'struct' doc - default big/network) 
+
+        >>> z = 'b67c01662ff6964a'.decode('hex')
+        >>> xtea_decrypt('0123456789012345',z)
+        'ABCDEFGH'
+
+        Only need to change byte order if sending/receiving from 
+        alternative endian implementation 
+
+        >>> z = 'ea0c3d7c1c22557f'.decode('hex')
+        >>> xtea_decrypt('0123456789012345',z,endian="<")
+        'ABCDEFGH'
+
+    """
+    v0,v1 = struct.unpack(endian+"2L",block)
+    k = struct.unpack(endian+"4L",key)
+    delta,mask = 0x9e3779b9L,0xffffffffL
+    sum = (delta * n) & mask
+    for round in range(n):
+        v1 = (v1 - (((v0<<4 ^ v0>>5) + v0) ^ (sum + k[sum>>11 & 3]))) & mask
+        sum = (sum - delta) & mask
+        v0 = (v0 - (((v1<<4 ^ v1>>5) + v1) ^ (sum + k[sum & 3]))) & mask
+    return struct.pack(endian+"2L",v0,v1)
+
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()


Property changes on: xtea/trunk/src/xtea.py
___________________________________________________________________
Name: svn:keywords
   + 'Id Revision'
Name: svn:eol-style
   + native

Added: xtea/trunk/version.txt
===================================================================
--- xtea/trunk/version.txt	                        (rev 0)
+++ xtea/trunk/version.txt	2007-02-27 16:22:39 UTC (rev 210)
@@ -0,0 +1 @@
+1.0


Property changes on: xtea/trunk/version.txt
___________________________________________________________________
Name: svn:keywords
   + 'Id Revision'
Name: svn:eol-style
   + native


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