(SQL Server) Create XML Digital Signature using a ECDSA Key

Demonstrates how to create an XML digital signature using a ECDSA key.

This example requires Chilkat v9.5.0.69 or greater.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

// Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
//
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @sTmp0 nvarchar(4000)
    -- This example requires the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    -- The SOAP XML to be signed in this example contains the following:

    -- <?xml version="1.0" encoding="UTF-8" standalone="no" ?>
    -- <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
    --     <SOAP-ENV:Header>
    --         <wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" SOAP-ENV:mustUnderstand="1"></wsse:Security>
    --     </SOAP-ENV:Header>
    --     <SOAP-ENV:Body xmlns:SOAP-SEC="http://schemas.xmlsoap.org/soap/security/2000-12" SOAP-SEC:id="Body">
    --         <z:FooBar xmlns:z="http://example.com" />
    --     </SOAP-ENV:Body>
    -- </SOAP-ENV:Envelope>
    -- 

    -- The above XML is available at https://www.chilkatsoft.com/exampleData/soapToSign.xml
    -- Fetch the XML and then sign it..

    DECLARE @url nvarchar(4000)
    SELECT @url = 'https://www.chilkatsoft.com/exampleData/soapToSign.xml'
    DECLARE @http int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.Http', @http OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @sbSoapXml int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.StringBuilder', @sbSoapXml OUT

    DECLARE @success int
    EXEC sp_OAMethod @http, 'QuickGetSb', @success OUT, @url, @sbSoapXml
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @sbSoapXml
        RETURN
      END

    -- This example uses an ECDSA private key for signing.  
    -- There are many ways to load an ECDSA private key using Chilkat.  This example
    -- will load from an unencrypted PEM file.

    -- For your convenience, Chilkat put this sample ECDSA PEM here:  https://www.chilkatsoft.com/exampleData/secp256r1-key.zip
    DECLARE @ecKey int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.PrivateKey', @ecKey OUT

    EXEC sp_OAMethod @ecKey, 'LoadPemFile', @success OUT, 'qa_data/ecc/secp256r1-key.pem'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ecKey, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @sbSoapXml
        EXEC @hr = sp_OADestroy @ecKey
        RETURN
      END

    -- To create the XML digital signature (i.e. embed the signature within
    -- the SOAP XML), we specify what is desired, and 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_9_5_0.XmlDSigGen', @xmlSigGen OUT

    -- In this example, the Signature will be placed within the wsse: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', 'SOAP-ENV:Envelope|SOAP-ENV:Header|wsse:Security'

    -- An XML digital signature contains one or more references.  A given reference
    -- can be a same-document reference (to an XML fragment), or an external reference.
    -- This example will add a single same-document reference.  We'll add a reference to the XML fragment
    -- at SOAP-ENV:Body, which is indicated by providing the value of the "Id" attribute (where "Id" is case
    -- insensitive).  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 SHA-256 and Exclusive XML Canonicalization.
    EXEC sp_OAMethod @xmlSigGen, 'AddSameDocRef', @success OUT, 'Body', 'sha256', 'EXCL_C14N', '', ''

    -- Let's provide the ECDSA key to be used for signing:
    EXEC sp_OAMethod @xmlSigGen, 'SetPrivateKey', @success OUT, @ecKey

    -- We're leaving the following properties at their default values:
    -- 
    --    - SigNamespacePrefix (default is "ds")
    --    - SignedInfoCanonAlg  (default is EXCL_C14N)
    --    - SignedInfoDigestMethod (default is sha256)
    --    - KeyInfoType (default is "KeyValue", where the ECDSA public key is included in the Signature)

    -- Note: Each Reference specifies its own algorithms for XML canonicalization and hashing.
    -- The SignedInfo part also has specified hash and canonicalization algorithms, which may be different
    -- than the algorithms used in the References.
    -- In this example, we use Exclusive XML Canonicalization and SHA-256 throughout.

    -- Finally, we're going to set one property that's optional, but commonly used.
    -- It's the SignedInfoPrefixList.  In this case, we're using Exclusive Canonicalization, and the signature
    -- will be placed in a location within the XML document where namespace prefixes are used in the ancestors.
    -- Specifically, the "wsse" and "SOAP-ENV" namespace prefixes are used.
    EXEC sp_OASetProperty @xmlSigGen, 'SignedInfoPrefixList', 'wsse SOAP-ENV'

    -- OK, everything's specified, so let's create the XML digital signature:
    -- This in-place signs the XML.  If successful, sbSoapXml will contain the 
    -- XML with the digital signature at the specified location.
    EXEC sp_OAMethod @xmlSigGen, 'CreateXmlDSigSb', @success OUT, @sbSoapXml
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @xmlSigGen, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @sbSoapXml
        EXEC @hr = sp_OADestroy @ecKey
        EXEC @hr = sp_OADestroy @xmlSigGen
        RETURN
      END

    -- Examine the signed SOAP XML:
    EXEC sp_OAMethod @sbSoapXml, 'GetAsString', @sTmp0 OUT
    PRINT @sTmp0

    -- This is the signed SOAP XML.
    -- 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" ?>
    -- <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
    --     <SOAP-ENV:Header>
    --         <wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" SOAP-ENV:mustUnderstand="1"><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#"><InclusiveNamespaces xmlns="http://www.w3.org/2001/10/xml-exc-c14n#" PrefixList="wsse SOAP-ENV"/></ds:CanonicalizationMethod><ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha256"/><ds:Reference URI="#Body"><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>OwgHPZNfDkXnZsjpfzXqAcT3RV3HzmTsEy2bP44FJ0M=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>jmPSGgtirHSjjcs/o0NIDwwvy4aFBCEosSN+XP5NLVuGpRYnS2EM7mItiw6TKmESAoJYV23ZN4pZ9BFRKSvZqw==</ds:SignatureValue><ds:KeyInfo><ds:KeyValue><ds:ECKeyValue xmlns="http://www.w3.org/2009/xmldsig11#"><ds:NamedCurve URI="urn:oid:1.2.840.10045.3.1.7" /><ds:PublicKey>BOVKaiLPKEDChhkA64UEBOXTv/VFHnhrUPN+bXqCvEl7rroAYpH5tKzbiGTtMSlp4JO9Pxg44zeX7EoWDvOrpD0=</ds:PublicKey></ds:ECKeyValue></ds:KeyValue></ds:KeyInfo></ds:Signature></wsse:Security>
    --     </SOAP-ENV:Header>
    --     <SOAP-ENV:Body xmlns:SOAP-SEC="http://schemas.xmlsoap.org/soap/security/2000-12" SOAP-SEC:id="Body">
    --         <z:FooBar xmlns:z="http://example.com" />
    --     </SOAP-ENV:Body>
    -- </SOAP-ENV:Envelope>

    -- The above signed XML contains the ECDSA public key in the ECKeyValue fragment (within the ds:KeyInfo).
    -- The signature can easily be verified like this:

    DECLARE @verifier int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.XmlDSig', @verifier OUT

    -- First load the XML containing the signature(s) to be verified.
    EXEC sp_OAMethod @verifier, 'LoadSignatureSb', @success OUT, @sbSoapXml
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @verifier, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @sbSoapXml
        EXEC @hr = sp_OADestroy @ecKey
        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 @sbSoapXml
    EXEC @hr = sp_OADestroy @ecKey
    EXEC @hr = sp_OADestroy @xmlSigGen
    EXEC @hr = sp_OADestroy @verifier


END
GO