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C

Get Certificate CRL Distribution Points

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Demonstrates how to get a certificate's CRL Distribution Points extension data (assuming it exists). In the vast majority of cases, there will be one CRL Distribution Point.

Note: This example requires Chilkat v9.5.0.76 or greater.

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C
#include <C_CkCert.h>
#include <C_CkXml.h>
#include <C_CkStringBuilder.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkCert cert;
    const char *extensionXmlStr;
    HCkXml xml;
    HCkStringBuilder sbDistPoint;

    success = FALSE;

    cert = CkCert_Create();

    success = CkCert_LoadFromFile(cert,"qa_data/certs/test_haswdt.cer");
    if (success != TRUE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkCert_Dispose(cert);
        return;
    }

    // Get the CRL Distribution Points extension, which is at OID 2.5.29.31
    extensionXmlStr = CkCert_getExtensionAsXml(cert,"2.5.29.31");
    if (CkCert_getLastMethodSuccess(cert) == FALSE) {
        printf("Certificate does not have the CDP extension.\n");
        CkCert_Dispose(cert);
        return;
    }

    xml = CkXml_Create();
    CkXml_LoadXml(xml,extensionXmlStr);

    // See what we have..
    printf("%s\n",CkXml_getXml(xml));

    // We should get XML like this:

    // <?xml version="1.0" encoding="utf-8" ?>
    // <sequence>
    //     <sequence>
    //         <contextSpecific tag="0" constructed="1">
    //             <contextSpecific tag="0" constructed="1">
    //                 <contextSpecific tag="6" constructed="0">aHR0cDovL2NybC5jb21vZG9jYS5jb20vQ09NT0RPUlNBQ2xpZW50QXV0aGVudGljYXRpb25hbmRTZWN1
    // cmVFbWFpbENBLmNybA==</contextSpecific>
    //             </contextSpecific>
    //         </contextSpecific>
    //     </sequence>
    // </sequence>
    // 

    // Assuming there is one CRL Distribution Point...
    sbDistPoint = CkStringBuilder_Create();
    success = CkXml_GetChildContentSb(xml,"sequence|contextSpecific|contextSpecific|contextSpecific",sbDistPoint);
    if (success == TRUE) {
        CkStringBuilder_Decode(sbDistPoint,"base64","utf-8");
        printf("CRL Distribution Point:  %s\n",CkStringBuilder_getAsString(sbDistPoint));
    }

    // Sample output:
    // CRL Distribution Point:  http://crl.comodoca.com/COMODORSAClientAuthenticationandSecureEmailCA.crl


    CkCert_Dispose(cert);
    CkXml_Dispose(xml);
    CkStringBuilder_Dispose(sbDistPoint);

    }