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

See more Signing in the Cloud Examples

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);

    }