(C) Sign XML (XAdES) in the Cloud using AWS KMS

See more Signing in the Cloud Examples

Demonstrates how to sign XML using AWS KMS. The signing of the hash happens in AWK KMS. Everything else involving the updating the XML to add the signature happens locally within Chilkat.

Note: This example requires Chilkat v9.5.0.96 or greater.

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#include <C_CkStringBuilder.h>
#include <C_CkCert.h>
#include <C_CkJsonObject.h>
#include <C_CkXmlDSigGen.h>

void ChilkatSample(void)
    {
    HCkStringBuilder sbXml;
    BOOL bCrlf;
    HCkCert cert;
    BOOL success;
    HCkJsonObject jsonAwsKms;
    HCkXmlDSigGen gen;
    BOOL bUsePrivateKey;

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

    // Create the XML to be signed.
    sbXml = CkStringBuilder_Create();

    bCrlf = TRUE;
    CkStringBuilder_AppendLine(sbXml,"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?>",bCrlf);
    CkStringBuilder_AppendLine(sbXml,"<SOAP-ENV:Envelope xmlns:SOAP-ENV=\"http://schemas.xmlsoap.org/soap/envelope/\">",bCrlf);
    CkStringBuilder_AppendLine(sbXml,"    <SOAP-ENV:Header>",bCrlf);
    CkStringBuilder_AppendLine(sbXml,"        <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>",bCrlf);
    CkStringBuilder_AppendLine(sbXml,"    </SOAP-ENV:Header>",bCrlf);
    CkStringBuilder_AppendLine(sbXml,"    <SOAP-ENV:Body xmlns:SOAP-SEC=\"http://schemas.xmlsoap.org/soap/security/2000-12\" SOAP-SEC:id=\"Body\">",bCrlf);
    CkStringBuilder_AppendLine(sbXml,"        <z:FooBar xmlns:z=\"http://example.com\" />",bCrlf);
    CkStringBuilder_AppendLine(sbXml,"    </SOAP-ENV:Body>",bCrlf);
    CkStringBuilder_AppendLine(sbXml,"</SOAP-ENV:Envelope>",bCrlf);

    // Load the certificate used for signing.  The certificate's private key is stored in AWS KMS
    // However, we still need the certificate locally (without private key).
    cert = CkCert_Create();
    success = CkCert_LoadFromFile(cert,"qa_data/certs/myCert.cer");
    if (success == FALSE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkStringBuilder_Dispose(sbXml);
        CkCert_Dispose(cert);
        return;
    }

    // Here's a screenshot of our private key AWS KMS:
    

    // To sign using AWS KMS, 
    // add the following lines of code to specify your AWS authentication credentials,
    // and the ID of the KMS private key.
    jsonAwsKms = CkJsonObject_Create();
    // Set the "service" equal to "aws_kms" to tell Chilkat to use AWS KMS for signing.
    CkJsonObject_UpdateString(jsonAwsKms,"service","aws_kms");
    CkJsonObject_UpdateString(jsonAwsKms,"access_key","ACCESS_KEY");
    CkJsonObject_UpdateString(jsonAwsKms,"secret_key","SECRET_KEY");
    // Make sure to specify the correct region for your case.
    CkJsonObject_UpdateString(jsonAwsKms,"region","us-west-2");
    // In the above screenshot, our key ID is "187012e8-008f-4fc7-b100-5efe6146dff2".  You will use your key ID.
    CkJsonObject_UpdateString(jsonAwsKms,"key_id","187012e8-008f-4fc7-b100-5efe6146dff2");

    success = CkCert_SetCloudSigner(cert,jsonAwsKms);

    // Prepare for signing...
    gen = CkXmlDSigGen_Create();

    // Indicate where the Signature will be inserted.
    CkXmlDSigGen_putSigLocation(gen,"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"
    CkXmlDSigGen_AddSameDocRef(gen,"Body","sha1","EXCL_C14N","","");

    // (You can read about the SignedInfoPrefixList in the online reference documentation.  It's optional..)
    CkXmlDSigGen_putSignedInfoPrefixList(gen,"wsse SOAP-ENV");

    CkXmlDSigGen_putKeyInfoType(gen,"X509Data");
    CkXmlDSigGen_putX509Type(gen,"IssuerSerial");

    bUsePrivateKey = TRUE;
    success = CkXmlDSigGen_SetX509Cert(gen,cert,bUsePrivateKey);
    if (success != TRUE) {
        printf("%s\n",CkXmlDSigGen_lastErrorText(gen));
        CkCert_Dispose(cert);
        CkStringBuilder_Dispose(sbXml);
        CkCert_Dispose(cert);
        CkJsonObject_Dispose(jsonAwsKms);
        CkXmlDSigGen_Dispose(gen);
        return;
    }

    // Everything's specified.  Now create and insert the Signature
    // (The actual signing of the hash will happen on the AWS KMS server.)
    success = CkXmlDSigGen_CreateXmlDSigSb(gen,sbXml);
    if (success != TRUE) {
        printf("%s\n",CkXmlDSigGen_lastErrorText(gen));
        CkStringBuilder_Dispose(sbXml);
        CkCert_Dispose(cert);
        CkJsonObject_Dispose(jsonAwsKms);
        CkXmlDSigGen_Dispose(gen);
        return;
    }

    // Examine the XML with the digital signature inserted
    printf("%s\n",CkStringBuilder_getAsString(sbXml));

    // --------------------------------------------------------------------------------
    // Also see Chilkat's Online WSDL Code Generator
    // to generate code and SOAP Request and Response XML for each operation in a WSDL.
    // --------------------------------------------------------------------------------


    CkStringBuilder_Dispose(sbXml);
    CkCert_Dispose(cert);
    CkJsonObject_Dispose(jsonAwsKms);
    CkXmlDSigGen_Dispose(gen);

    }