(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 <C_CkCrypt2.h>
#include <C_CkJsonObject.h>
#include <C_CkDtObj.h>

void ChilkatSample(void)
    {
    HCkCrypt2 crypt;
    const char *outputFile;
    const char *inFile;
    BOOL success;
    HCkJsonObject json;
    HCkDtObj authAttrSigningTimeUtctime;
    const char *issuerCN;
    const char *serial;
    const char *strVal;
    const char *certSubjectKeyIdentifier;
    const char *certDigestAlgOid;
    const char *certDigestAlgName;
    const char *signingAlgOid;
    const char *signingAlgName;
    const char *authAttrContentTypeName;
    const char *authAttrContentTypeOid;
    const char *authAttrSigningTimeName;
    const char *authAttrMessageDigestName;
    const char *authAttrMessageDigestDigest;
    const char *authAttrSigningCertificateV2Name;
    const char *authAttrSigningCertificateV2Der;
    int i;
    int count_i;

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

    crypt = CkCrypt2_Create();

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

    // Verify the signature and extract the contained file, which in this case is XML.
    success = CkCrypt2_VerifyP7M(crypt,inFile,outputFile);
    if (success == FALSE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkCrypt2_Dispose(crypt);
        return;
    }

    printf("Signature validated.\n");

    // Now let's examine the information about the signature.
    json = CkCrypt2_LastJsonData(crypt);
    if (CkCrypt2_getLastMethodSuccess(crypt) == FALSE) {
        // This should never be the case...
        printf("No information available.\n");
        CkCrypt2_Dispose(crypt);
        return;
    }

    CkJsonObject_putEmitCompact(json,FALSE);
    printf("%s\n",CkJsonObject_emit(json));

    // 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.

    authAttrSigningTimeUtctime = CkDtObj_Create();

    i = 0;
    count_i = CkJsonObject_SizeOfArray(json,"pkcs7.verify.certs");
    while (i < count_i) {
        CkJsonObject_putI(json,i);
        issuerCN = CkJsonObject_stringOf(json,"pkcs7.verify.certs[i].issuerCN");
        serial = CkJsonObject_stringOf(json,"pkcs7.verify.certs[i].serial");
        i = i + 1;
    }

    i = 0;
    count_i = CkJsonObject_SizeOfArray(json,"pkcs7.verify.digestAlgorithms");
    while (i < count_i) {
        CkJsonObject_putI(json,i);
        strVal = CkJsonObject_stringOf(json,"pkcs7.verify.digestAlgorithms[i]");
        i = i + 1;
    }

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

    CkJsonObject_Dispose(json);


    CkCrypt2_Dispose(crypt);
    CkDtObj_Dispose(authAttrSigningTimeUtctime);

    }