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SQL Server
Create XML Digital Signature using a DSA Key
See more XML Digital Signatures Examples
Demonstrates how to create an XML digital signature using a DSA key.This example requires Chilkat v9.5.0.69 or greater.
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-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
DECLARE @hr int
-- Important: Do not use nvarchar(max). See the warning about using nvarchar(max).
DECLARE @sTmp0 nvarchar(4000)
DECLARE @success int
SELECT @success = 0
-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.
-- The XML to be signed in this example contains the following:
-- <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-- <Envelope>
-- <Header>
-- <Security>
-- </Security>
-- </Header>
-- <Body Id="abc">
-- <z:FooBar xmlns:z="https://www.example-code.com"/>
-- </Body>
-- </Envelope>
-- The above XML is available at https://www.chilkatsoft.com/exampleData/xmlToSign.xml
-- Fetch the XML and then sign it..
DECLARE @url nvarchar(4000)
SELECT @url = 'https://www.chilkatsoft.com/exampleData/xmlToSign.xml'
DECLARE @http int
EXEC @hr = sp_OACreate 'Chilkat.Http', @http OUT
IF @hr <> 0
BEGIN
PRINT 'Failed to create ActiveX component'
RETURN
END
DECLARE @sbXml int
EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbXml OUT
EXEC sp_OAMethod @http, 'QuickGetSb', @success OUT, @url, @sbXml
IF @success <> 1
BEGIN
EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
EXEC @hr = sp_OADestroy @http
EXEC @hr = sp_OADestroy @sbXml
RETURN
END
-- This example uses a DSA private key for signing.
-- There are many ways of getting an DSA private key using Chilkat. This example
-- will load it from an encrypted PEM file.
-- In case you would like to use it, I put the DSA private key PEM file here:
-- https://www.chilkatsoft.com/exampleData/dsa1024_secret.zip
-- The password is "secret".
DECLARE @dsaKey int
EXEC @hr = sp_OACreate 'Chilkat.PrivateKey', @dsaKey OUT
EXEC sp_OAMethod @dsaKey, 'LoadEncryptedPemFile', @success OUT, 'qa_data/dsa/dsa1024_secret.pem', 'secret'
IF @success <> 1
BEGIN
EXEC sp_OAGetProperty @dsaKey, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
EXEC @hr = sp_OADestroy @http
EXEC @hr = sp_OADestroy @sbXml
EXEC @hr = sp_OADestroy @dsaKey
RETURN
END
-- To create the XML digital signature (i.e. embed the signature within
-- the XML), first specify what is desired, then call the method to
-- create the XML signature.
--
-- For example, the application must provide the following:
-- - Where to put the signature.
-- - What to sign.
-- - The algorithms to be used.
-- - The key to be used for signing.
--
DECLARE @xmlSigGen int
EXEC @hr = sp_OACreate 'Chilkat.XmlDSigGen', @xmlSigGen OUT
-- In this example, we're going to put the signature within the Security element.
-- To specify the location, set the SigLocation property to the XML path to this element,
-- using vertical bar characters to separate tags.
EXEC sp_OASetProperty @xmlSigGen, 'SigLocation', 'Envelope|Header|Security'
-- An XML digital signature contains one or more references. These can be references to the parts
-- of the XML document to be signed (a same document reference), or can be external references.
-- This example will add a single same-document reference. We'll add a reference to the XML fragment
-- at Body, which is indicated by providing the value of the "ID" attribute (where "ID" is case
-- insensitive). In this case, we specify "abc" because Body has an Id="abc".
-- This causes the <Body> ... </Body> XML fragment to be signed.
--
-- For each same-document reference, we must also indicate the hash algorithm and XML canonicalization
-- algorithm to be used. For this example we'll choose SHA1 and Exclusive XML Canonicalization.
EXEC sp_OAMethod @xmlSigGen, 'AddSameDocRef', @success OUT, 'abc', 'sha1', 'EXCL_C14N', '', ''
-- Provide the DSA key to be used for signing:
EXEC sp_OAMethod @xmlSigGen, 'SetPrivateKey', @success OUT, @dsaKey
-- We're leaving the following properties at their default values:
--
-- - SigNamespacePrefix (default is "ds")
-- - SignedInfoCanonAlg (default is EXCL_C14N)
-- - KeyInfoType (default is "KeyValue", where the DSA public key is included in the Signature)
-- Note: Each Reference has it's own specified algorithms for XML canonicalization and hashing,
-- and the actual signature part (the SignedInfo) has it's own hash/canonicalization algorithm.
-- They may or may not be the same. In this example, we use Exclusive XML Canonicalization and SHA1 throughout.
-- The default SignedInfoDigestMethod is sha256, which is a good choice. This example will
-- change it to sha1.
EXEC sp_OASetProperty @xmlSigGen, 'SignedInfoDigestMethod', 'sha1'
-- OK, everything's specified, so let's create the XML digital signature:
-- This in-place signs the XML. If successful, sbXml will contain the
-- XML with the digital signature at the specified location.
EXEC sp_OAMethod @xmlSigGen, 'CreateXmlDSigSb', @success OUT, @sbXml
IF @success <> 1
BEGIN
EXEC sp_OAGetProperty @xmlSigGen, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
EXEC @hr = sp_OADestroy @http
EXEC @hr = sp_OADestroy @sbXml
EXEC @hr = sp_OADestroy @dsaKey
EXEC @hr = sp_OADestroy @xmlSigGen
RETURN
END
-- Examine the signed XML:
EXEC sp_OAMethod @sbXml, 'GetAsString', @sTmp0 OUT
PRINT @sTmp0
-- Below is the signed XML that is produced.
-- Chilkat emits the Signature in compact form on a single line. Whitespace in XML signatures
-- matters. Chilkat's opinion is that writing the Signature without whitespace minimizes the chance
-- for problems with whatever software might be verifying the signature.
-- <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-- <Envelope>
-- <Header>
-- <Security>
-- <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#"><ds:SignedInfo><ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/><ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#dsa-sha1"/><ds:Reference URI="#abc"><ds:Transforms><ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/></ds:Transforms><ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/><ds:DigestValue>77X3L6odxTBow1W1dIiqZW1foow=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>Ci/KiAqoQLvNyK94n8TJwdJ6dVpIIy8tJg+9s8utmB92cW8lTd+U7g==</ds:SignatureValue><ds:KeyInfo><ds:KeyValue><ds:DSAKeyValue><ds:P>AN+Af9FvnqYl84Own8m/MHza9vVFEbpySOiWyeIM8diDjaES9i+UykaX9BGc0oaRJHtrHhe+gboMBGHfP+gYcgbqzeyVCi2kHghRD/TK7uI4jN8Yv8tfM6AO0QrDFfxFq4IV+qTZbSoCkbWaopQ+kEOY6B4btFxJ1YuE48mExMZ3</ds:P><ds:Q>AOCv5pwf4kvMW37Yzt0iH6URKOlD</ds:Q><ds:G>FO3eoDcpuU9Z25OQGFtC+M2ifczcKyRkFwTauGR3mIw0wePPiu3Ocr7A81SA8GQ9x3hWO5jyP//jL3jxYy8fgBg2RXwiic3nwT2rZfu50g6tPUpz1stKz/+Mxjulo6XuaMSOWwjU021IxVMzxQ1/L8QiwiIrwxvfQOaMY8HJgvw=</ds:G><ds:Y>JJmZQvWtrZ+Nb2YV47SfGAave8uOIedGlmg+CseoqKZC2aFcWM6kR0giUwQx834dhxQScRhqzxFxQPk/x+5hyG8LQbXW+BELmT1BiyodobYUAet4rSIt4EU4KU0iYw1drpcWT1jqI07l5xNi28heYSfSF5Odv2qwXxVKDSEeEkM=</ds:Y></ds:DSAKeyValue></ds:KeyValue></ds:KeyInfo></ds:Signature></Security>
-- </Header>
-- <Body Id="abc">
-- <z:FooBar xmlns:z="https://www.example-code.com"/>
-- </Body>
-- </Envelope>
-- The above signed XML contains the DSA public key in the DSAKeyValue fragment (within the ds:KeyInfo).
-- The signature can easily be verified like this:
DECLARE @verifier int
EXEC @hr = sp_OACreate 'Chilkat.XmlDSig', @verifier OUT
-- First load the XML containing the signature(s) to be verified.
EXEC sp_OAMethod @verifier, 'LoadSignatureSb', @success OUT, @sbXml
IF @success <> 1
BEGIN
EXEC sp_OAGetProperty @verifier, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
EXEC @hr = sp_OADestroy @http
EXEC @hr = sp_OADestroy @sbXml
EXEC @hr = sp_OADestroy @dsaKey
EXEC @hr = sp_OADestroy @xmlSigGen
EXEC @hr = sp_OADestroy @verifier
RETURN
END
DECLARE @bVerified int
EXEC sp_OAMethod @verifier, 'VerifySignature', @bVerified OUT, 1
IF @bVerified <> 1
BEGIN
EXEC sp_OAGetProperty @verifier, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
END
PRINT 'Signature verified = ' + @bVerified
EXEC @hr = sp_OADestroy @http
EXEC @hr = sp_OADestroy @sbXml
EXEC @hr = sp_OADestroy @dsaKey
EXEC @hr = sp_OADestroy @xmlSigGen
EXEC @hr = sp_OADestroy @verifier
END
GO