XML integration with ADO+

Written by Pawan Bangar


One ofrepparttar most important design goals for ADO+ was powerful XML support. Microsoft designed ADO+ hand in hand withrepparttar 105104 .NET XML framework. Both are components of a single architecture. The unification of ADO+ withrepparttar 105105 XML framework happens inrepparttar 105106 dataset.

For beginners datasets has methods that can read and write XML. For reading XML,repparttar 105107 XML framework parser is used, either explicitly or implicitly. For writing XML out,repparttar 105108 XML framework XmlWriter is utilized.

In spite of whererepparttar 105109 data originated,repparttar 105110 dataset can save out its contents, both schema and data as XML. The schema is encoded as an internal W3C schema section, generally known as XSD, andrepparttar 105111 data is encoded as XML that be conventional to that schema. Becauserepparttar 105112 dataset's native serialization format is XML, it is an tremendous medium for moving data between tiers in a disconnected fashion just likerepparttar 105113 disconnected recordset.

Indeed, .NET Web services make intense use of datasets to transport data inrepparttar 105114 context of a schema between tiers of an application. Just like populatingrepparttar 105115 dataset via its object model or through managed providers, loadingrepparttar 105116 dataset with XML is a two stage process.

1) The schema is created, and thenrepparttar 105117 data is loaded. Ifrepparttar 105118 XML document comes with a schema, that schema is used to createrepparttar 105119 relational structure ofrepparttar 105120 dataset. If not,repparttar 105121 dataset can infer schema fromrepparttar 105122 containment relationships withinrepparttar 105123 document. In general speaking, elements that are not scalar valued are mapped to tables, whereas attributes and scalar valued elements are mapped to columns.

2) The process of inferring schema is useful when constructing an application that has to consume XML that comes with no schema. But for production applications, it is highly desirable to takerepparttar 105124 inferred schema, modify it as appropriate, and load that schema in beforerepparttar 105125 actual data is loaded. That way,repparttar 105126 process of loadingrepparttar 105127 document is deterministic, so you don't have to worry about what a slight change inrepparttar 105128 incoming document will do torepparttar 105129 inference heuristics.



Digital Signaturesin xml

Written by Pawan Bangar


The Xml Digital Signatures providesrepparttar security services of data integrity, authentication, and nonrepudiation.

In a simple shorthand notationrepparttar 105102 structures of DSIG signatures with its four elements. Elements appear zero or more times if followed by "*", zero or once if followed by"?", and once or more if followed by "+". When not followed by a symbol, elements appear only once.

Removing attributes and contents inrepparttar 105103 notation it becomes an example of signature object using three of its four elements.

The signature object containsrepparttar 105104 cryptographic hash of any signed information, and a reference torepparttar 105105 information itself. The signed information may be an arbitrary document. However, often, it will be an XML object. The ability to sign only specific elements of XML documents is one ofrepparttar 105106 most important features of DSIG. It letsrepparttar 105107 unsigned parts ofrepparttar 105108 XML document is enhanced, modified, or removed for privacy or efficiency, keepingrepparttar 105109 signature valid.

DSIG signatures may contain eitherrepparttar 105110 signed XML object contained inrepparttar 105111 XML object, or detached fromrepparttar 105112 signed object or document. Whenrepparttar 105113 signed XML object envelopsrepparttar 105114 signature,repparttar 105115 enveloped signature value itself is not included inrepparttar 105116 signature calculation and validation computation. For this you userepparttar 105117 enveloped-signature transform, removingrepparttar 105118 whole signature element in which it is contained fromrepparttar 105119 digest calculation.

Public key digital signatures that provide nonrepudiation, such as RSA, are computationally intensive operations; therefore, DSIG also allows shared-key authentication that provides authentication but nonrepudiation. Collision resistant hashing ofrepparttar 105120 signed content is also used to save computational requirements.

Generating DSIG signatures:

1. Identity resources to be signed. 2. Calculatingrepparttar 105121 digest value and composing reference elements for each resource. 3. Composingrepparttar 105122 signed info element from all references. 4. Computing value of signature method over identity resources to be signed element by applying algorithms like DSA, RSA-SHA1, etc 5. Composingrepparttar 105123 signature elements with signedInfo, signature value, identity key used to sign, and other optional objects like signature properties.

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