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M c14n.py


			
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Joshua Boverhof 19 years ago
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6df2d56678
1 changed files with 147 additions and 282 deletions
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    -282
      c14n.py

+ 147
- 282
c14n.py View File

@@ -1,43 +1,42 @@
#! /usr/bin/env python
"""Compatibility module, imported by ZSI if you don't have PyXML 0.7.
No copyright violations -- we're only using parts of PyXML that we
wrote.
"""
_copyright = '''ZSI: Zolera Soap Infrastructure.
Copyright 2001, Zolera Systems, Inc. All Rights Reserved.
Copyright 2002-2003, Rich Salz. All Rights Reserved.
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, and/or
sell copies of the Software, and to permit persons to whom the Software
is furnished to do so, provided that the above copyright notice(s) and
this permission notice appear in all copies of the Software and that
both the above copyright notice(s) and this permission notice appear in
supporting documentation.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS
INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT
OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE
OR PERFORMANCE OF THIS SOFTWARE.
Except as contained in this notice, the name of a copyright holder
shall not be used in advertising or otherwise to promote the sale, use
or other dealings in this Software without prior written authorization
of the copyright holder.
'''XML Canonicalization
Patches Applied to xml.dom.ext.c14n:
http://sourceforge.net/projects/pyxml/
[ 1444526 ] c14n.py: http://www.w3.org/TR/xml-exc-c14n/ fix
-- includes [ 829905 ] c14n.py fix for bug #825115,
Date Submitted: 2003-10-24 23:43
-- include dependent namespace declarations declared in ancestor nodes
(checking attributes and tags),
-- handle InclusiveNamespaces PrefixList parameter
This module generates canonical XML of a document or element.
http://www.w3.org/TR/2001/REC-xml-c14n-20010315
and includes a prototype of exclusive canonicalization
http://www.w3.org/Signature/Drafts/xml-exc-c14n
Requires PyXML 0.7.0 or later.
Known issues if using Ft.Lib.pDomlette:
1. Unicode
2. does not white space normalize attributes of type NMTOKEN and ID?
3. seems to be include "\n" after importing external entities?
Note, this version processes a DOM tree, and consequently it processes
namespace nodes as attributes, not from a node's namespace axis. This
permits simple document and element canonicalization without
XPath. When XPath is used, the XPath result node list is passed and used to
determine if the node is in the XPath result list, but little else.
Authors:
"Joseph M. Reagle Jr." <reagle@w3.org>
"Rich Salz" <rsalz@zolera.com>
$Date$ by $Author$
'''

_copyright += "\n\nPortions are also: "
_copyright += '''Copyright 2001, Zolera Systems Inc. All Rights Reserved.
_copyright = '''Copyright 2001, Zolera Systems Inc. All Rights Reserved.
Copyright 2001, MIT. All Rights Reserved.

Distributed under the terms of:
@@ -48,184 +47,25 @@ or
http://www.w3.org/Consortium/Legal/copyright-software-19980720
'''

import string
from xml.dom import Node
from Namespaces import XMLNS
import cStringIO as StringIO
try:
from xml.dom.ext import c14n
except ImportError, ex:
_implementation2 = None
_attrs = lambda E: (E.attributes and E.attributes.values()) or []
_children = lambda E: E.childNodes or []
else:
class _implementation2(c14n._implementation):
"""Patch for exclusive c14n
"""
def __init__(self, node, write, **kw):
self.unsuppressedPrefixes = kw.get('unsuppressedPrefixes')
self._exclusive = None
if node.nodeType == Node.ELEMENT_NODE:
if not c14n._inclusive(self):
self._exclusive = self._inherit_context(node)
c14n._implementation.__init__(self, node, write, **kw)

def _do_element(self, node, initial_other_attrs = []):
"""Patch for the xml.dom.ext.c14n implemenation _do_element method.
This fixes a problem with sorting of namespaces.
"""
# Get state (from the stack) make local copies.
# ns_parent -- NS declarations in parent
# ns_rendered -- NS nodes rendered by ancestors
# ns_local -- NS declarations relevant to this element
# xml_attrs -- Attributes in XML namespace from parent
# xml_attrs_local -- Local attributes in XML namespace.
ns_parent, ns_rendered, xml_attrs = \
self.state[0], self.state[1].copy(), self.state[2].copy() #0422
ns_local = ns_parent.copy()
xml_attrs_local = {}

# Divide attributes into NS, XML, and others.
#other_attrs = initial_other_attrs[:]
other_attrs = []
sort_these_attrs = initial_other_attrs[:]

in_subset = c14n._in_subset(self.subset, node)
#for a in _attrs(node):
sort_these_attrs +=c14n._attrs(node)
for a in sort_these_attrs:
if a.namespaceURI == c14n.XMLNS.BASE:
n = a.nodeName
if n == "xmlns:": n = "xmlns" # DOM bug workaround
ns_local[n] = a.nodeValue
elif a.namespaceURI == c14n.XMLNS.XML:
if c14n._inclusive(self) or (in_subset and c14n._in_subset(self.subset, a)): #020925 Test to see if attribute node in subset
xml_attrs_local[a.nodeName] = a #0426
else:
if c14n._in_subset(self.subset, a): #020925 Test to see if attribute node in subset
other_attrs.append(a)
#add local xml:foo attributes to ancestor's xml:foo attributes
xml_attrs.update(xml_attrs_local)

# Render the node
W, name = self.write, None
if in_subset:
name = node.nodeName
W('<')
W(name)

# Create list of NS attributes to render.
ns_to_render = []
for n,v in ns_local.items():

# If default namespace is XMLNS.BASE or empty,
# and if an ancestor was the same
if n == "xmlns" and v in [ c14n.XMLNS.BASE, '' ] \
and ns_rendered.get('xmlns') in [ c14n.XMLNS.BASE, '', None ]:
continue

# "omit namespace node with local name xml, which defines
# the xml prefix, if its string value is
# http://www.w3.org/XML/1998/namespace."
if n in ["xmlns:xml", "xml"] \
and v in [ 'http://www.w3.org/XML/1998/namespace' ]:
continue


# If not previously rendered
# and it's inclusive or utilized
if (n,v) not in ns_rendered.items() \
and (c14n._inclusive(self) or \
c14n._utilized(n, node, other_attrs, self.unsuppressedPrefixes)):
ns_to_render.append((n, v))

#####################################
# JRB
#####################################
if not c14n._inclusive(self):
if node.prefix is None:
look_for = [('xmlns', node.namespaceURI),]
else:
look_for = [('xmlns:%s' %node.prefix, node.namespaceURI),]
for a in c14n._attrs(node):
if a.namespaceURI != XMLNS.BASE:
#print "ATTRIBUTE: ", (a.namespaceURI, a.prefix)
if a.prefix:
#print "APREFIX: ", a.prefix
look_for.append(('xmlns:%s' %a.prefix, a.namespaceURI))

for key,namespaceURI in look_for:
if ns_rendered.has_key(key):
if ns_rendered[key] == namespaceURI:
# Dont write out
pass
else:
#ns_to_render += [(key, namespaceURI)]
pass
elif (key,namespaceURI) in ns_to_render:
# Dont write out
pass
else:
# Unique write out, rewrite to render
ns_local[key] = namespaceURI
for a in self._exclusive:
if a.nodeName == key:
#self._do_attr(a.nodeName, a.value)
#ns_rendered[key] = namespaceURI
#break
ns_to_render += [(a.nodeName, a.value)]
break
elif key is None and a.nodeName == 'xmlns':
#print "DEFAULT: ", (a.nodeName, a.value)
ns_to_render += [(a.nodeName, a.value)]
break
#print "KEY: ", key
else:
#print "Look for: ", look_for
#print "NS_TO_RENDER: ", ns_to_render
#print "EXCLUSIVE NS: ", map(lambda f: (f.nodeName,f.value),self._exclusive)
raise RuntimeError, \
'can not find namespace (%s="%s") for exclusive canonicalization'\
%(key, namespaceURI)
#####################################



# Sort and render the ns, marking what was rendered.
ns_to_render.sort(c14n._sorter_ns)
for n,v in ns_to_render:
#XXX JRB, getting 'xmlns,None' here when xmlns=''
if v: self._do_attr(n, v)
else:
v = ''
self._do_attr(n, v)
ns_rendered[n]=v #0417

# If exclusive or the parent is in the subset, add the local xml attributes
# Else, add all local and ancestor xml attributes
# Sort and render the attributes.
if not c14n._inclusive(self) or c14n._in_subset(self.subset,node.parentNode): #0426
other_attrs.extend(xml_attrs_local.values())
else:
other_attrs.extend(xml_attrs.values())
#print "OTHER: ", other_attrs
other_attrs.sort(c14n._sorter)
for a in other_attrs:
self._do_attr(a.nodeName, a.value)
W('>')


# Push state, recurse, pop state.
state, self.state = self.state, (ns_local, ns_rendered, xml_attrs)
for c in c14n._children(node):
c14n._implementation.handlers[c.nodeType](self, c)
self.state = state

if name: W('</%s>' % name)
c14n._implementation.handlers[c14n.Node.ELEMENT_NODE] = _do_element


_IN_XML_NS = lambda n: n.namespaceURI == XMLNS.XML
try:
from xml.ns import XMLNS
except:
class XMLNS:
BASE = "http://www.w3.org/2000/xmlns/"
XML = "http://www.w3.org/XML/1998/namespace"
try:
import cStringIO
StringIO = cStringIO
except ImportError:
import StringIO

_attrs = lambda E: (E.attributes and E.attributes.values()) or []
_children = lambda E: E.childNodes or []
_IN_XML_NS = lambda n: n.name.startswith("xmlns")
_inclusive = lambda n: n.unsuppressedPrefixes == None


# Does a document/PI has lesser/greater document order than the
# first element?
@@ -251,24 +91,53 @@ def _sorter_ns(n1,n2):
def _utilized(n, node, other_attrs, unsuppressedPrefixes):
'''_utilized(n, node, other_attrs, unsuppressedPrefixes) -> boolean
Return true if that nodespace is utilized within the node'''

if n.startswith('xmlns:'):
n = n[6:]
elif n.startswith('xmlns'):
n = n[5:]
if n == node.prefix or n in unsuppressedPrefixes: return 1
if (n=="" and node.prefix in ["#default", None]) or \
n == node.prefix or n in unsuppressedPrefixes:
return 1
for attr in other_attrs:
if n == attr.prefix: return 1
# For exclusive need to look at attributes
if unsuppressedPrefixes is not None:
for attr in _attrs(node):
if n == attr.prefix: return 1
return 0

_in_subset = lambda subset, node: not subset or node in subset

#
# JRB. Currently there is a bug in do_element, but since the underlying
# Data Structures in c14n have changed I can't just apply the
# _implementation2 patch above. But this will work OK for most uses,
# just not XML Signatures.
#
def _inclusiveNamespacePrefixes(node, context, unsuppressedPrefixes):
'''http://www.w3.org/TR/xml-exc-c14n/
InclusiveNamespaces PrefixList parameter, which lists namespace prefixes that
are handled in the manner described by the Canonical XML Recommendation'''
inclusive = []
if node.prefix:
usedPrefixes = ['xmlns:%s' %node.prefix]
else:
usedPrefixes = ['xmlns']

for a in _attrs(node):
if a.nodeName.startswith('xmlns') or not a.prefix: continue
usedPrefixes.append('xmlns:%s' %a.prefix)

for attr in context:
n = attr.nodeName
if n in unsuppressedPrefixes:
inclusive.append(attr)
elif n.startswith('xmlns:') and n[6:] in unsuppressedPrefixes:
inclusive.append(attr)
elif n.startswith('xmlns') and n[5:] in unsuppressedPrefixes:
inclusive.append(attr)
elif attr.nodeName in usedPrefixes:
inclusive.append(attr)

return inclusive

#_in_subset = lambda subset, node: not subset or node in subset
_in_subset = lambda subset, node: subset is None or node in subset # rich's tweak


class _implementation:
'''Implementation class for C14N. This accompanies a node during it's
processing and includes the parameters and processing state.'''
@@ -278,25 +147,23 @@ class _implementation:

def __init__(self, node, write, **kw):
'''Create and run the implementation.'''

self.write = write
self.subset = kw.get('subset')
if self.subset:
self.comments = kw.get('comments', 1)
else:
self.comments = kw.get('comments', 0)
self.comments = kw.get('comments', 0)
self.unsuppressedPrefixes = kw.get('unsuppressedPrefixes')
nsdict = kw.get('nsdict', { 'xml': XMLNS.XML, 'xmlns': XMLNS.BASE })
# Processing state.
self.state = (nsdict, ['xml'], [])
self.state = (nsdict, {'xml':''}, {}) #0422
if node.nodeType == Node.DOCUMENT_NODE:
self._do_document(node)
elif node.nodeType == Node.ELEMENT_NODE:
self.documentOrder = _Element # At document element
if self.unsuppressedPrefixes is not None:
self._do_element(node)
if not _inclusive(self):
inherited = _inclusiveNamespacePrefixes(node, self._inherit_context(node),
self.unsuppressedPrefixes)
self._do_element(node, inherited)
else:
inherited = self._inherit_context(node)
self._do_element(node, inherited)
@@ -355,11 +222,10 @@ class _implementation:
Process a text or CDATA node. Render various special characters
as their C14N entity representations.'''
if not _in_subset(self.subset, node): return
s = node.data \
.replace("&", "&amp;") \
.replace("<", "&lt;") \
.replace(">", "&gt;") \
.replace("\015", "&#xD;")
s = string.replace(node.data, "&", "&amp;")
s = string.replace(s, "<", "&lt;")
s = string.replace(s, ">", "&gt;")
s = string.replace(s, "\015", "&#xD;")
if s: self.write(s)
handlers[Node.TEXT_NODE] = _do_text
handlers[Node.CDATA_SECTION_NODE] = _do_text
@@ -410,46 +276,51 @@ class _implementation:
W(' ')
W(n)
W('="')
s = value \
.replace("&", "&amp;") \
.replace("<", "&lt;") \
.replace('"', '&quot;') \
.replace('\011', '&#x9') \
.replace('\012', '&#xA') \
.replace('\015', '&#xD')
s = string.replace(value, "&", "&amp;")
s = string.replace(s, "<", "&lt;")
s = string.replace(s, '"', '&quot;')
s = string.replace(s, '\011', '&#x9')
s = string.replace(s, '\012', '&#xA')
s = string.replace(s, '\015', '&#xD')
W(s)
W('"')


def _do_element(self, node, initial_other_attrs = []):
'''_do_element(self, node, initial_other_attrs = []) -> None
Process an element (and its children).'''

# Get state (from the stack) make local copies.
# ns_parent -- NS declarations in parent
# ns_rendered -- NS nodes rendered by ancestors
# xml_attrs -- Attributes in XML namespace from parent
# ns_local -- NS declarations relevant to this element
# ns_parent -- NS declarations in parent
# ns_rendered -- NS nodes rendered by ancestors
# ns_local -- NS declarations relevant to this element
# xml_attrs -- Attributes in XML namespace from parent
# xml_attrs_local -- Local attributes in XML namespace.
ns_parent, ns_rendered, xml_attrs = \
self.state[0], self.state[1][:], self.state[2][:]
self.state[0], self.state[1].copy(), self.state[2].copy() #0422
ns_local = ns_parent.copy()
xml_attrs_local = {}

# Divide attributes into NS, XML, and others.
other_attrs = initial_other_attrs[:]
other_attrs = []
in_subset = _in_subset(self.subset, node)
for a in _attrs(node):
for a in _attrs(node) + initial_other_attrs:
if a.namespaceURI == XMLNS.BASE:
n = a.nodeName
if n == "xmlns:": n = "xmlns" # DOM bug workaround
ns_local[n] = a.nodeValue
elif a.namespaceURI == XMLNS.XML:
if self.unsuppressedPrefixes is None or in_subset:
xml_attrs.append(a)
if _inclusive(self) or (in_subset and _in_subset(self.subset, a)): #020925 Test to see if attribute node in subset
xml_attrs_local[a.nodeName] = a #0426
else:
other_attrs.append(a)
if _in_subset(self.subset, a): #020925 Test to see if attribute node in subset
other_attrs.append(a)
#add local xml:foo attributes to ancestor's xml:foo attributes
xml_attrs.update(xml_attrs_local)

# Render the node
W, name = self.write, None
if in_subset:
if in_subset:
name = node.nodeName
W('<')
W(name)
@@ -457,25 +328,25 @@ class _implementation:
# Create list of NS attributes to render.
ns_to_render = []
for n,v in ns_local.items():
pval = ns_parent.get(n)

# If default namespace is XMLNS.BASE or empty, skip
if n == "xmlns" \
and v in [ XMLNS.BASE, '' ] and pval in [ XMLNS.BASE, '' ]:
# If default namespace is XMLNS.BASE or empty,
# and if an ancestor was the same
if n == "xmlns" and v in [ XMLNS.BASE, '' ] \
and ns_rendered.get('xmlns') in [ XMLNS.BASE, '', None ]:
continue

# "omit namespace node with local name xml, which defines
# the xml prefix, if its string value is
# http://www.w3.org/XML/1998/namespace."
if n == "xmlns:xml" \
if n in ["xmlns:xml", "xml"] \
and v in [ 'http://www.w3.org/XML/1998/namespace' ]:
continue

# If different from parent, or parent didn't render
# and if not exclusive, or this prefix is needed or
# not suppressed
if (v != pval or n not in ns_rendered) \
and (self.unsuppressedPrefixes is None or \
# If not previously rendered
# and it's inclusive or utilized
if (n,v) not in ns_rendered.items() \
and (_inclusive(self) or \
_utilized(n, node, other_attrs, self.unsuppressedPrefixes)):
ns_to_render.append((n, v))

@@ -483,12 +354,15 @@ class _implementation:
ns_to_render.sort(_sorter_ns)
for n,v in ns_to_render:
self._do_attr(n, v)
ns_rendered.append(n)
ns_rendered[n]=v #0417

# Add in the XML attributes (don't pass to children, since
# we're rendering them), sort, and render.
other_attrs.extend(xml_attrs)
xml_attrs = []
# If exclusive or the parent is in the subset, add the local xml attributes
# Else, add all local and ancestor xml attributes
# Sort and render the attributes.
if not _inclusive(self) or _in_subset(self.subset,node.parentNode): #0426
other_attrs.extend(xml_attrs_local.values())
else:
other_attrs.extend(xml_attrs.values())
other_attrs.sort(_sorter)
for a in other_attrs:
self._do_attr(a.nodeName, a.value)
@@ -520,17 +394,8 @@ def Canonicalize(node, output=None, **kw):
prefixes that should be inherited.
'''
if output:
if _implementation2 is None:
_implementation(node, output.write, **kw)
else:
apply(_implementation2, (node, output.write), kw)
apply(_implementation, (node, output.write), kw)
else:
s = StringIO.StringIO()
if _implementation2 is None:
_implementation(node, s.write, **kw)
else:
apply(_implementation2, (node, s.write), kw)
apply(_implementation, (node, s.write), kw)
return s.getvalue()


if __name__ == '__main__': print _copyright

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