PureBasic
PureBasic
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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IncludeFile "CkXmlDSigGen.pb"
IncludeFile "CkHttp.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkPrivateKey.pb"
IncludeFile "CkXmlDSig.pb"
Procedure ChilkatExample()
success.i = 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..
url.s = "https://www.chilkatsoft.com/exampleData/xmlToSign.xml"
http.i = CkHttp::ckCreate()
If http.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
sbXml.i = CkStringBuilder::ckCreate()
If sbXml.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
success = CkHttp::ckQuickGetSb(http,url,sbXml)
If success <> 1
Debug CkHttp::ckLastErrorText(http)
CkHttp::ckDispose(http)
CkStringBuilder::ckDispose(sbXml)
ProcedureReturn
EndIf
; 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".
dsaKey.i = CkPrivateKey::ckCreate()
If dsaKey.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
success = CkPrivateKey::ckLoadEncryptedPemFile(dsaKey,"qa_data/dsa/dsa1024_secret.pem","secret")
If success <> 1
Debug CkPrivateKey::ckLastErrorText(dsaKey)
CkHttp::ckDispose(http)
CkStringBuilder::ckDispose(sbXml)
CkPrivateKey::ckDispose(dsaKey)
ProcedureReturn
EndIf
; 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.
;
xmlSigGen.i = CkXmlDSigGen::ckCreate()
If xmlSigGen.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
; 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.
CkXmlDSigGen::setCkSigLocation(xmlSigGen, "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.
CkXmlDSigGen::ckAddSameDocRef(xmlSigGen,"abc","sha1","EXCL_C14N","","")
; Provide the DSA key to be used for signing:
CkXmlDSigGen::ckSetPrivateKey(xmlSigGen,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.
CkXmlDSigGen::setCkSignedInfoDigestMethod(xmlSigGen, "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.
success = CkXmlDSigGen::ckCreateXmlDSigSb(xmlSigGen,sbXml)
If success <> 1
Debug CkXmlDSigGen::ckLastErrorText(xmlSigGen)
CkHttp::ckDispose(http)
CkStringBuilder::ckDispose(sbXml)
CkPrivateKey::ckDispose(dsaKey)
CkXmlDSigGen::ckDispose(xmlSigGen)
ProcedureReturn
EndIf
; Examine the signed XML:
Debug CkStringBuilder::ckGetAsString(sbXml)
; 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:
verifier.i = CkXmlDSig::ckCreate()
If verifier.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
; First load the XML containing the signature(s) to be verified.
success = CkXmlDSig::ckLoadSignatureSb(verifier,sbXml)
If success <> 1
Debug CkXmlDSig::ckLastErrorText(verifier)
CkHttp::ckDispose(http)
CkStringBuilder::ckDispose(sbXml)
CkPrivateKey::ckDispose(dsaKey)
CkXmlDSigGen::ckDispose(xmlSigGen)
CkXmlDSig::ckDispose(verifier)
ProcedureReturn
EndIf
bVerified.i = CkXmlDSig::ckVerifySignature(verifier,1)
If bVerified <> 1
Debug CkXmlDSig::ckLastErrorText(verifier)
EndIf
Debug "Signature verified = " + Str(bVerified)
CkHttp::ckDispose(http)
CkStringBuilder::ckDispose(sbXml)
CkPrivateKey::ckDispose(dsaKey)
CkXmlDSigGen::ckDispose(xmlSigGen)
CkXmlDSig::ckDispose(verifier)
ProcedureReturn
EndProcedure