Straightforward C14N¶

Performs the C14N transformation of a straightforward XML document.

Documentation¶

A Python interface to SC14N <https://www.cryptosys.net/sc14n/>.

class sc14n.C14n¶

Perform C14N transformation of XML document.

static file2digest(xmlfile, nameorid='', tranopt=0, digalg=0, tranmethod=0, exclparams='', advopts=0)¶

Compute digest value of C14N transformation of XML document (file-to-digest).

Parameters

xmlfile (str) -- Name of input XML file.
nameorid (str) -- To specify the tag name or Id. See remarks for C14n.file2file().
tranopt (Tran) -- Transformation option.
digalg (DigAlg) -- Digest algorithm.
tranmethod (TranMethod) -- Transformation method.
exclparams (str) -- InclusiveNamespaces PrefixList parameter for exclusive c14n.
advopts (AdvOptions) -- Advanced option flags.

Returns

Message digest in base64-encoded string.

Return type

str

static file2file(outfile, xmlfile, nameorid='', tranopt=0, tranmethod=0, exclparams='', advopts=0)¶

Perform C14N transformation of XML document (file-to-file).

Parameters

outfile (str) -- Name of output file to create.
xmlfile (str) -- Name of input XML file.
nameorid (str) -- To specify the tag name or Id.
tranopt (Tran) -- Transformation option.
tranmethod (TranMethod) -- Transformation method.
exclparams (str) -- InclusiveNamespaces PrefixList parameter for exclusive c14n.
advopts (AdvOptions) -- Advanced option flags.

Returns

True if successful, False otherwise.

Return type

bool

Remarks:

Use the nameorid parameter to specify the element of the XML document to include or exclude.

With options Tran.OMITBYTAG or Tran.SUBSETBYTAG, nameorid specifies the element's tag name.

By default, the first element with a matching tag name will be chosen.
To specify the Nth element, write as tagname[N] where N=1,2,3,...

With options Tran.OMITBYID or Tran.SUBSETBYID, nameorid specifies the element's Id.

The default Id attribute name is Id, so the argument myvalue will find the element with attribute Id="myvalue".
To use a different attribute name - for example ID - write in the form ID=myvalue with no quotes.

Exactly one element will be excluded or included. Tag names and Id values are case sensitive. It is an error (NO_DATA_ERROR) if no matching element is found.

Examples

>>> # Example 1. Excludes the first element with the tag name <Signature>
>>> r = C14n.file2file("c14nfile1.txt", "input.xml", "Signature", Tran.OMITBYTAG)
True
>>> # Example 2. Finds and transforms the first element with the tag name <SignedInfo>
>>> r = C14n.file2file("c14nfile2.txt", "input.xml", "SignedInfo", Tran.SUBSETBYTAG)
True
>>> # Example 3. Finds and transforms the third element with the tag name <Data>
>>> r = C14n.file2file("c14nfile3.txt", "input.xml", "Data[3]", Tran.SUBSETBYTAG)
True
>>> # Example 4. Finds and transforms the element with attribute Id="foo"
>>> r = C14n.file2file("c14nfile4.txt", "input.xml", "foo", Tran.SUBSETBYID)
True
>>> # Example 5. Finds and transforms the element with attribute ID="bar"
>>> r = C14n.file2file("c14nfile5.txt", "input.xml", "ID=bar", Tran.SUBSETBYID)
True
>>> # Example 6. Excludes element with attribute Id="thesig"
>>> r = C14n.file2file("c14nfile6.txt", "input.xml", "thesig", Tran.OMITBYID)
True

static file2string(xmlfile, nameorid='', tranopt=0, tranmethod=0, exclparams='', advopts=0)¶

Perform C14N transformation of XML document (file-to-string).

Parameters

xmlfile (str) -- Name of input XML file.
nameorid (str) -- To specify the tag name or Id. See remarks for C14n.file2file().
tranopt (Tran) -- Transformation option.
tranmethod (TranMethod) -- Transformation method.
exclparams (str) -- InclusiveNamespaces PrefixList parameter for exclusive c14n.
advopts (AdvOptions) -- Advanced option flags.

Returns

UTF-8-encoded string.

Return type

str

static string2digest(xmldata, nameorid='', tranopt=0, digalg=0, tranmethod=0, exclparams='', advopts=0)¶

Compute digest value of C14N transformation of XML document (string-to-digest).

Parameters

xmldata (str) -- XML data to be processed.
nameorid (str) -- To specify the tag name or Id. See remarks for C14n.file2file().
tranopt (Tran) -- Transformation option.
digalg (DigAlg) -- Digest algorithm.
tranmethod (TranMethod) -- Transformation method.
exclparams (str) -- InclusiveNamespaces PrefixList parameter for exclusive c14n.
advopts (AdvOptions) -- Advanced option flags.

Returns

Message digest in base64-encoded string.

Return type

str

static string2string(xmldata, nameorid='', tranopt=0, tranmethod=0, exclparams='', advopts=0)¶

Perform C14N transformation of XML document (string-to-string).

Parameters

xmldata (str) -- XML data to be processed.
nameorid (str) -- To specify the tag name or Id. See remarks for C14n.file2file().
tranopt (Tran) -- Transformation option.
tranmethod (TranMethod) -- Transformation method.
exclparams (str) -- InclusiveNamespaces PrefixList parameter for exclusive c14n.
advopts (AdvOptions) -- Advanced option flags.

Returns

UTF-8-encoded string.

Return type

str

class sc14n.Tran¶

Transformation options.

See also: remarks for C14n.file2file().

ENTIRE = 0¶: Transform the entire document.

OMITBYID = 17¶: Omit (exclude) the element with the given Id.

OMITBYTAG = 1¶: Omit (exclude) the element with the given tag name.

SUBSETBYID = 18¶: Transform the subset with the given Id.

SUBSETBYTAG = 2¶: Transform the subset with the given tag name.

class sc14n.TranMethod¶

Transformation methods.

EXCLUSIVE = 256¶: Exclusive c14n without comments from RFC 3741.

EXCLUSIVE_WITHCOMMENTS = 2304¶: Exclusive C14N with comments from RFC 3741.

INCLUSIVE = 0¶: Inclusive c14n without comments from RFC 3076 (default).

INCLUSIVE_WITHCOMMENTS = 2048¶: Inclusive C14N with comments from RFC 3076.

class sc14n.DigAlg¶

Message digest algorithms.

DEFAULT = 0¶: Use default digest algorithm.

SHA1 = 0¶: Use SHA-1 digest (default)

SHA256 = 8192¶: Use SHA-256 digest

class sc14n.AdvOptions¶

Advanced option flags.

DEFAULT = 0¶: Use default options.

FLATTEN = 65536¶: Flatten the XML - remove all ignorable whitespace between tags.

class sc14n.Gen¶

General info about the core library DLL.

static compile_time()¶: Return date and time the core library DLL was last compiled.

static core_platform()¶: Return the platform of the core library DLL: Win32 or Win64.

static licence_type()¶: Return licence type: D = Developer T = Trial.

static module_name()¶: Return full path name of the current process's core library DLL.

static version()¶: Return the release version of the core library DLL as an integer value.

class sc14n.Err¶

Details of errors returned by the core library.

static error_lookup(n)¶: Return a description of error code n.

static last_error()¶: Return the last error message set by the toolkit, if any.

exception sc14n.Error(value)¶: Raised when a call to a core library function returns an error, or some obviously wrong parameter is detected.

Notes¶

The following C14N transformations are supported:
- "inclusive canonicalization" from Canonical XML Version 1.0 (reproduced as RFC 3076) with identifiers
  http://www.w3.org/TR/2001/REC-xml-c14n-20010315
  
  http://www.w3.org/TR/2001/REC-xml-c14n-20010315#WithComments
- "exclusive canonicalization" from Exclusive XML Canonical Version 1.0 (reproduced as RFC 3741) with identifiers
  http://www.w3.org/2001/10/xml-exc-c14n#
  
  http://www.w3.org/2001/10/xml-exc-c14n#WithComments
Input is expected to be a well-formed XML document.
Supported XML encodings are UTF-8, ISO-8859-1 and US-ASCII.
With Python 3, input in a "string" is expected to be a standard Python 3 UTF-8 string (str type). Output in a "string" is always a UTF-8-encoded str type.

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