Ruby
Create XML Digital Signature using Certificate on Smart Card

Demonstrates how to load a certificate located on a smart card or USB token and then use it for creating an XML digital signature such that the cryptographic signing happens on the smart card.
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require 'chilkat'

success = false

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

scmd = Chilkat::CkScMinidriver.new()

# Reader names (smart card readers or USB tokens) can be discovered
# via List Readers or Find Smart Cards
readerName = "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0"
success = scmd.AcquireContext(readerName)
if (success == false)
    print scmd.lastErrorText() + "\n";
    exit
end

# If successful, the name of the currently inserted smart card is available:
print "Card name: " + scmd.cardName() + "\n";

# If desired, perform regular PIN authentication with the smartcard.
# For more details about smart card PIN authentication, see the Smart Card PIN Authentication Example
retval = scmd.PinAuthenticate("user","000000")
if (retval != 0)
    print "PIN Authentication failed." + "\n";
end

# You can find a cerficate using any of the following certificate parts:
# "subjectDN" -- The full distinguished name of the cert.
# "subjectDN_withTags" -- Same as above, but in a format that includes the subject part tags, such as the "CN=" in "CN=something"
# "subjectCN" -- The common name part (CN) of the certificate's subject.
# "serial" -- The certificate serial number.
# "serial:issuerCN" -- The certificate serial number + the issuer's common name, delimited with a colon char.
# These are the same certificate parts that can be retrieved by listing certificates on the smart card (or USB token).
# See List Certificates on Smart Card Example
certPart = "subjectCN"
partValue = "PIVKey E42D60A759D39147A26E0AF2FB1183C5"

# If the certificate is found, it is loaded into the cert object.
cert = Chilkat::CkCert.new()
success = scmd.FindCert(certPart,partValue,cert)
if (success == false)
    print "Failed to find the certificate." + "\n";
    scmd.DeleteContext()
    exit
end

print "Successfully loaded the cert object from the smart card / USB token." + "\n";

# Note: When successful, the cert object is internally linked to the ScMinidriver object's authenticated session.
# The cert object can now be used to sign or do other cryptographic operations that occur on the smart card / USB token.
# If your application calls PinDeauthenticate or DeleteContext, the cert will no longer be able to sign on the smart card
# because the smart card ScMinidriver session will no longer be authenticated or deleted.

# ------------------------------------------------------------------------------------------------------------
# We have the certificate.  Now let's do the XML digital signature..

# Create the following XML to be signed:

# <?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>

xml = Chilkat::CkXml.new()
xml.put_Tag("SOAP-ENV:Envelope")
xml.AddAttribute("xmlns:SOAP-ENV","http://schemas.xmlsoap.org/soap/envelope/")
xml.UpdateAttrAt("SOAP-ENV:Header|wsse:Security",true,"xmlns:wsse","http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd")
xml.UpdateAttrAt("SOAP-ENV:Header|wsse:Security",true,"SOAP-ENV:mustUnderstand","1")
xml.UpdateAttrAt("SOAP-ENV:Body",true,"xmlns:SOAP-SEC","http://schemas.xmlsoap.org/soap/security/2000-12")
xml.UpdateAttrAt("SOAP-ENV:Body",true,"SOAP-SEC:id","Body")
xml.UpdateAttrAt("SOAP-ENV:Body|z:FooBar",true,"xmlns:z","http://example.com")

# Prepare for signing...
gen = Chilkat::CkXmlDSigGen.new()

# Indicate where the Signature will be inserted.
gen.put_SigLocation("SOAP-ENV:Envelope|SOAP-ENV:Header|wsse:Security")

# Add a reference to the fragment of the XML to be signed.

# Note: "Body" refers to the XML element having an "id" equal to "Body", where "id" is case insensitive
# and where any namespace might qualify the attribute.  In this case, the SOAP-ENV:Body fragment is signed
# NOT because the tag = "Body", but because it has SOAP-SEC:id="Body"
gen.AddSameDocRef("Body","sha1","EXCL_C14N","","")

# (You can read about the SignedInfoPrefixList in the online reference documentation.  It's optional..)
gen.put_SignedInfoPrefixList("wsse SOAP-ENV")

# Provide the private key for signing via the certificate, and indicate that
# we want the base64 of the certificate embedded in the KeyInfo.
gen.put_KeyInfoType("X509Data")
gen.put_X509Type("Certificate")

# Note: Our certificate was loaded from the smartcard and is internally linked to the authenticated ScMinidriver session.
# The signing will occur on the smart card using the chosen certificate.
bUsePrivateKey = true
success = gen.SetX509Cert(cert,bUsePrivateKey)
if (success != true)
    print gen.lastErrorText() + "\n";
    exit
end

# Everything's specified.  Now create and insert the Signature
sbXml = Chilkat::CkStringBuilder.new()
xml.GetXmlSb(sbXml)
success = gen.CreateXmlDSigSb(sbXml)
if (success != true)
    print gen.lastErrorText() + "\n";
    exit
end

# Examine the XML with the digital signature inserted
print sbXml.getAsString() + "\n";

# ------------------------------------------------------------------------------------------------------------
# Cleanup our ScMinidriver session...

# When finished with operations that required authentication, you may if you wish, deauthenticate the session.
success = scmd.PinDeauthenticate("user")
if (success == false)
    print scmd.lastErrorText() + "\n";
end

# Delete the context when finished with the card.
success = scmd.DeleteContext()
if (success == false)
    print scmd.lastErrorText() + "\n";
end