DataFlex
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.
DataFlex
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 DataFlex Downloads
Use ChilkatAx-win32.pkg
Procedure Test
Boolean iSuccess
String sUrl
Handle hoHttp
Variant vSbXml
Handle hoSbXml
Handle hoVerifier
Variant vXmlKeyInfo
Handle hoXmlKeyInfo
Handle hoSbKeyName
Variant vPubKey
Handle hoPubKey
Boolean iBVerified
String sTemp1
Boolean bTemp1
Move False To iSuccess
// 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:
Move "https://www.chilkatsoft.com/exampleData/signedUsingKeyName.xml" To sUrl
Get Create (RefClass(cComChilkatHttp)) To hoHttp
If (Not(IsComObjectCreated(hoHttp))) Begin
Send CreateComObject of hoHttp
End
Get Create (RefClass(cComChilkatStringBuilder)) To hoSbXml
If (Not(IsComObjectCreated(hoSbXml))) Begin
Send CreateComObject of hoSbXml
End
Get pvComObject of hoSbXml to vSbXml
Get ComQuickGetSb Of hoHttp sUrl vSbXml To iSuccess
If (iSuccess <> True) Begin
Get ComLastErrorText Of hoHttp To sTemp1
Showln sTemp1
Procedure_Return
End
Get Create (RefClass(cComChilkatXmlDSig)) To hoVerifier
If (Not(IsComObjectCreated(hoVerifier))) Begin
Send CreateComObject of hoVerifier
End
// Load the XML containing the signature to be verified.
Get pvComObject of hoSbXml to vSbXml
Get ComLoadSignatureSb Of hoVerifier vSbXml To iSuccess
If (iSuccess <> True) Begin
Get ComLastErrorText Of hoVerifier To sTemp1
Showln sTemp1
Procedure_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.
Get ComGetKeyInfo Of hoVerifier To vXmlKeyInfo
If (IsComObject(vXmlKeyInfo)) Begin
Get Create (RefClass(cComChilkatXml)) To hoXmlKeyInfo
Set pvComObject Of hoXmlKeyInfo To vXmlKeyInfo
End
Get ComLastMethodSuccess Of hoVerifier To bTemp1
If (bTemp1 = False) Begin
Showln "There is no KeyInfo available in the Signature."
Procedure_Return
End
// Examine the XML:
Get ComGetXml Of hoXmlKeyInfo To sTemp1
Showln sTemp1
// The KeyInfo XML that is returned looks like this:
//
// <ds:KeyInfo>
// <ds:KeyName>dsaKey_123</ds:KeyName>
// </ds:KeyInfo>
//
// Get the KeyName.
Get Create (RefClass(cComChilkatStringBuilder)) To hoSbKeyName
If (Not(IsComObjectCreated(hoSbKeyName))) Begin
Send CreateComObject of hoSbKeyName
End
Get ComGetChildContent Of hoXmlKeyInfo "*:KeyName" To sTemp1
Get ComAppend Of hoSbKeyName sTemp1 To iSuccess
Send Destroy of hoXmlKeyInfo
// sbKeyName contains "dsaKey_123"
Get ComGetAsString Of hoSbKeyName To sTemp1
Showln sTemp1
// 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"
//
Get ComContentsEqual Of hoSbKeyName "dsaKey_123" False To bTemp1
If (bTemp1 = False) Begin
Showln "I don't know this key..."
Procedure_Return
End
// The DSA public key used in this example is available at:
// https://www.chilkatsoft.com/exampleData/dsa1024_public.zip
Get Create (RefClass(cComChilkatPublicKey)) To hoPubKey
If (Not(IsComObjectCreated(hoPubKey))) Begin
Send CreateComObject of hoPubKey
End
Get ComLoadFromFile Of hoPubKey "qa_data/dsa/dsa1024_public.pem" To iSuccess
If (iSuccess <> True) Begin
Get ComLastErrorText Of hoPubKey To sTemp1
Showln sTemp1
Procedure_Return
End
// Provide the DSA public key to the XML DSig verifier:
Get pvComObject of hoPubKey to vPubKey
Get ComSetPublicKey Of hoVerifier vPubKey To iSuccess
// Verify the signature
Get ComVerifySignature Of hoVerifier True To iBVerified
Showln "Signature verified = " iBVerified
End_Procedure