SQL Server
In this case, the public key is not specifically stored in the signed XML.
Rather, application specific information about the key is stored in the KeyName element.
This example uses the KeyName to find and matching public key.
SQL Server
Verify XML Digital Signature having KeyName
See more XML Digital Signatures Examples
Demonstrates how to verify an XML digital signature where the KeyInfo part contains the KeyName element.In this case, the public key is not specifically stored in the signed XML.
Rather, application specific information about the key is stored in the KeyName element.
This example uses the KeyName to find and matching public key.
This example requires Chilkat v9.5.0.69 or greater.
Chilkat SQL Server Downloads
-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
DECLARE @hr int
DECLARE @iTmp0 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 signed XML to be verified in this example contains the following:
--
-- <?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/2009/xmldsig11#dsa-sha256"/><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/2001/04/xmlenc#sha256"/><ds:DigestValue>XTjDIHSEsDNTO9yn4cKtyXjRUjPFXkOQOLYI5mueZhk=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>NXOIMevGCqFl0Dwtp2KkqkT05GRV8CjmHZ9LhFpt8/d7+lkIi7mITA==</ds:SignatureValue><ds:KeyInfo><ds:KeyName>dsaKey_123</ds:KeyName></ds:KeyInfo></ds:Signature></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/signedUsingKeyName.xml
-- First we'll fetch the signed XML:
DECLARE @url nvarchar(4000)
SELECT @url = 'https://www.chilkatsoft.com/exampleData/signedUsingKeyName.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
DECLARE @verifier int
EXEC @hr = sp_OACreate 'Chilkat.XmlDSig', @verifier OUT
-- Load the XML containing the signature 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 @verifier
RETURN
END
-- (The Chilkat XML Digital Signature API has the capability to handle XML documents with multiple signatures.
-- We know in advance that this signed XML has just one Signature, so we leave the dsig.Selector property at the
-- default value of 0.)
-- Let's get the KeyInfo XML so we can then get the KeyName.
DECLARE @xmlKeyInfo int
EXEC sp_OAMethod @verifier, 'GetKeyInfo', @xmlKeyInfo OUT
EXEC sp_OAGetProperty @verifier, 'LastMethodSuccess', @iTmp0 OUT
IF @iTmp0 = 0
BEGIN
PRINT 'There is no KeyInfo available in the Signature.'
EXEC @hr = sp_OADestroy @http
EXEC @hr = sp_OADestroy @sbXml
EXEC @hr = sp_OADestroy @verifier
RETURN
END
-- Examine the XML:
EXEC sp_OAMethod @xmlKeyInfo, 'GetXml', @sTmp0 OUT
PRINT @sTmp0
-- The KeyInfo XML that is returned looks like this:
--
-- <ds:KeyInfo>
-- <ds:KeyName>dsaKey_123</ds:KeyName>
-- </ds:KeyInfo>
--
-- Get the KeyName.
DECLARE @sbKeyName int
EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbKeyName OUT
EXEC sp_OAMethod @xmlKeyInfo, 'GetChildContent', @sTmp0 OUT, '*:KeyName'
EXEC sp_OAMethod @sbKeyName, 'Append', @success OUT, @sTmp0
EXEC @hr = sp_OADestroy @xmlKeyInfo
-- sbKeyName contains "dsaKey_123"
EXEC sp_OAMethod @sbKeyName, 'GetAsString', @sTmp0 OUT
PRINT @sTmp0
-- The application now locates and loads the public key for verification
-- based on the key name. This example will do the following:
-- If the key name equals "dsaKey_123", then load the DSA key from
-- "qa_data/dsa/dsa1024_public.pem"
--
EXEC sp_OAMethod @sbKeyName, 'ContentsEqual', @iTmp0 OUT, 'dsaKey_123', 0
IF @iTmp0 = 0
BEGIN
PRINT 'I don''t know this key...'
EXEC @hr = sp_OADestroy @http
EXEC @hr = sp_OADestroy @sbXml
EXEC @hr = sp_OADestroy @verifier
EXEC @hr = sp_OADestroy @sbKeyName
RETURN
END
-- The DSA public key used in this example is available at:
-- https://www.chilkatsoft.com/exampleData/dsa1024_public.zip
DECLARE @pubKey int
EXEC @hr = sp_OACreate 'Chilkat.PublicKey', @pubKey OUT
EXEC sp_OAMethod @pubKey, 'LoadFromFile', @success OUT, 'qa_data/dsa/dsa1024_public.pem'
IF @success <> 1
BEGIN
EXEC sp_OAGetProperty @pubKey, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
EXEC @hr = sp_OADestroy @http
EXEC @hr = sp_OADestroy @sbXml
EXEC @hr = sp_OADestroy @verifier
EXEC @hr = sp_OADestroy @sbKeyName
EXEC @hr = sp_OADestroy @pubKey
RETURN
END
-- Provide the DSA public key to the XML DSig verifier:
EXEC sp_OAMethod @verifier, 'SetPublicKey', @success OUT, @pubKey
-- Verify the signature
DECLARE @bVerified int
EXEC sp_OAMethod @verifier, 'VerifySignature', @bVerified OUT, 1
PRINT 'Signature verified = ' + @bVerified
EXEC @hr = sp_OADestroy @http
EXEC @hr = sp_OADestroy @sbXml
EXEC @hr = sp_OADestroy @verifier
EXEC @hr = sp_OADestroy @sbKeyName
EXEC @hr = sp_OADestroy @pubKey
END
GO