(C++) Verify a CAdES-BES Signature and Examine Signature Contents

Demonstrates how to validate a .p7m (.p7s) signature and examine the contents of the signature.

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#include <CkCrypt2.h>
#include <CkJsonObject.h>
#include <CkDtObj.h>

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

    CkCrypt2 crypt;

    const char *outputFile = "qa_output/original.xml";
    const char *inFile = "qa_data/p7m/fattura_signature.xml.p7m";

    // Verify the signature and extract the contained file, which in this case is XML.
    bool success = crypt.VerifyP7M(inFile,outputFile);
    if (success == false) {
        std::cout << crypt.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Signature validated." << "\r\n";

    // Now let's examine the information about the signature.
    CkJsonObject *json = crypt.LastJsonData();
    if (crypt.get_LastMethodSuccess() == false) {
        // This should never be the case...
        std::cout << "No information available." << "\r\n";
        return;
    }

    json->put_EmitCompact(false);
    std::cout << json->emit() << "\r\n";

    // Here's an example of the information about the signature:
    // {
    //   "pkcs7": {
    //     "verify": {
    //       "certs": [
    //         {
    //           "issuerCN": "Xyz EU Qualified Certificates CA G1",
    //           "serial": "99A28A51AC389999"
    //         }
    //       ],
    //       "useConstructedOctets": true,
    //       "digestAlgorithms": [
    //         "sha256"
    //       ],
    //       "signerInfo": [
    //         {
    //           "cert": {
    //             "subjectKeyIdentifier": "5VM4x8AWnXf07yzbXuLtbb0U3yY=",
    //             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
    //             "digestAlgName": "SHA256"
    //           },
    //           "signingAlgOid": "1.2.840.113549.1.1.11",
    //           "signingAlgName": "RSA-SHA256-PKCSV-1_5",
    //           "authAttr": {
    //             "1.2.840.113549.1.9.3": {
    //               "name": "contentType",
    //               "oid": "1.2.840.113549.1.7.1"
    //             },
    //             "1.2.840.113549.1.9.5": {
    //               "name": "signingTime",
    //               "utctime": "190901152340Z"
    //             },
    //             "1.2.840.113549.1.9.4": {
    //               "name": "messageDigest",
    //               "digest": "y+gd/zAQK33A//HInhaZba7w1fUJleV9AHbP1Ntx6U0="
    //             },
    //             "1.2.840.113549.1.9.16.2.47": {
    //               "name": "signingCertificateV2",
    //               "der": "MIH4MI..w4vv0="
    //             }
    //           }
    //         }
    //       ]
    //     }
    //   }
    // }

    // Use this online tool to generate parsing code from sample JSON: 
    // Generate Parsing Code from JSON

    // Chilkat functions returning "const char *" return a pointer to temporary internal memory owned and managed by Chilkat.
    // See this example explaining how this memory should be used: const char * functions.

    CkDtObj authAttrSigningTimeUtctime;
    const char *issuerCN = 0;
    const char *serial = 0;
    const char *strVal = 0;
    const char *certSubjectKeyIdentifier = 0;
    const char *certDigestAlgOid = 0;
    const char *certDigestAlgName = 0;
    const char *signingAlgOid = 0;
    const char *signingAlgName = 0;
    const char *authAttrContentTypeName = 0;
    const char *authAttrContentTypeOid = 0;
    const char *authAttrSigningTimeName = 0;
    const char *authAttrMessageDigestName = 0;
    const char *authAttrMessageDigestDigest = 0;
    const char *authAttrSigningCertificateV2Name = 0;
    const char *authAttrSigningCertificateV2Der = 0;

    int i = 0;
    int count_i = json->SizeOfArray("pkcs7.verify.certs");
    while (i < count_i) {
        json->put_I(i);
        issuerCN = json->stringOf("pkcs7.verify.certs[i].issuerCN");
        serial = json->stringOf("pkcs7.verify.certs[i].serial");
        i = i + 1;
    }

    i = 0;
    count_i = json->SizeOfArray("pkcs7.verify.digestAlgorithms");
    while (i < count_i) {
        json->put_I(i);
        strVal = json->stringOf("pkcs7.verify.digestAlgorithms[i]");
        i = i + 1;
    }

    i = 0;
    count_i = json->SizeOfArray("pkcs7.verify.signerInfo");
    while (i < count_i) {
        json->put_I(i);
        certSubjectKeyIdentifier = json->stringOf("pkcs7.verify.signerInfo[i].cert.subjectKeyIdentifier");
        certDigestAlgOid = json->stringOf("pkcs7.verify.signerInfo[i].cert.digestAlgOid");
        certDigestAlgName = json->stringOf("pkcs7.verify.signerInfo[i].cert.digestAlgName");
        signingAlgOid = json->stringOf("pkcs7.verify.signerInfo[i].signingAlgOid");
        signingAlgName = json->stringOf("pkcs7.verify.signerInfo[i].signingAlgName");
        authAttrContentTypeName = json->stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.3\".name");
        authAttrContentTypeOid = json->stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.3\".oid");
        authAttrSigningTimeName = json->stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.5\".name");
        json->DtOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.5\".utctime",false,authAttrSigningTimeUtctime);
        authAttrMessageDigestName = json->stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.4\".name");
        authAttrMessageDigestDigest = json->stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.4\".digest");
        authAttrSigningCertificateV2Name = json->stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.16.2.47\".name");
        authAttrSigningCertificateV2Der = json->stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.16.2.47\".der");
        i = i + 1;
    }

    delete json;
    }