XML Digital Signatures for Widgets support in Opera Presto 2.10

W3C references
XML Digital Signatures for Widgets

Opera Presto offers support for the following sections of the W3C XML Digital Signatures for Widgets. For your reference, items are hyperlinked to their place in the online W3C XML Digital Signatures for Widgets document.

Signature Algorithms

Algorithm Namespace Description Support
RSAwithSHA256 URI This algorithm is the recommended signature algorithm for the purposes of this specification.
The minimum key length is:
  • 2048 for RSA and DSA
The recommended key length is:
  • 4096 bits for RSA and DSA
Yes
DSAwithSHA1 URI This is an algorithm identifier for the DSA with SHA1 signature algorithm.
  • It extends SignatureAlgorithmIdentifier.
No
ECDSAwithSHA256 URI This is the The Elliptic Curve Digital Signature Algorithm.
  • It is the elliptic curve analogue of the DSA (DSS) signature method.
No

Digest Algorithms

Algorithm Namespace Description Support
SHA-256 URI A SHA-256 digest is a 256-bit string. Yes

Canonicalization Algorithms

Algorithm Namespace Description Support
XML Canonicalization 1.0 (omits comments) URI This is the recommended canonicalization algorithm for signature generation.
  • However, a signer can sign a widget package with one of the other algorithms given below.
  • It is optional for an implementation to support additional canonicalization algorithms.
Yes
Exclusive XML Canonicalization 1.0 (omits comments) URI This is the algorithm that generates the exclusive canonical form of a given XML document subset.
  • The term exclusive XML canonicalization refers to the process of applying the exclusive XML canonicalization method to an XML document subset.
Yes
Canonical XML 1.1 URI This is a revision to Canonical XML Version 1.0 to address issues related to inheritance of attributes in the XML namespace when canonicalizing document subsets.
  • This includes the requirement not to inherit xml:id, and to treat xml:base URI path processing properly.
  • Canonical XML Version 1.1 is applicable to XML 1.0 and defined in terms of the XPath 1.0 data model.
  • It is not defined for XML 1.1.
No

Author signature

An author signature is a widget signature with a signature file name that adheres to the naming convention for an author signature, and has a role element whose URI attribute is equivalent to the author role attribute value.

Namespace Description Support
URI It is intended to be generated by the author of the widget (i.e., the entity or entities whom claim authorship over the content of the widget package).
  • A widget package can contain zero or one author signatures.
  • The author signature can be used to determine:
    • Which entity alleges to have authored the widget.
    • That the integrity of the widget is as the author intended.
    • Whether two widgets came from the same author.
Yes

Distributor signatures

This is a widget signature with a signature file name that adheres to the naming convention for a distributor signature, and has a role element whose URI is equivalent to the distributor role attribute value.

Namespace Description Support
URI A distributor signature is intended to be generated by a third party (a distributor) that is distributing the widget on behalf of the author.
  • A widget package can contain zero, one, or more distributor signatures.
  • The distributor signature can be used to determine:
    • That a particular distributor has distributed a widget package.
    • That the integrity of the widget package is as the distributor intended.
Yes

Documentation

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