(MFC) P7S - Access Signature Information (date/time, certificate used, etc.)

Examine a PKCS7 signature (.p7s) and get information about it. Note: This example requires Chilkat v9.5.0.75 or greater.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkBinData.h>
#include <CkCrypt2.h>
#include <CkJsonObject.h>
#include <CkDateTime.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    // First load the .p7s file into a BinData object..
    CkBinData bd;
    bool success = bd.LoadFile("qa_data/p7s/sample.p7s");
    if (success != true) {
        strOut.append("Failed to load .p7s file.");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // IMPORTANT:  This example requires Chilkat v9.5.0.75 or greater.
    CkCrypt2 crypt;

    // Assuming this is a signature that contains the original data that was signed..
    success = crypt.OpaqueVerifyBd(bd);
    if (success != true) {
        strOut.append(crypt.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Examine the LastJsonData after signature verification..
    CkJsonObject *json = crypt.LastJsonData();
    json->put_EmitCompact(false);
    strOut.append(json->emit());
    strOut.append("\r\n");

    // --
    // IMPORTANT:  This example requires Chilkat v9.5.0.75 or greater.
    // --

    // Sample output...
    // Go to http://tools.chilkat.io/jsonParse.cshtml
    // and paste the JSON into the online form to generate JSON parsing code.

    // {
    //   "pkcs7": {
    //     "verify": {
    //       "digestAlgorithms": [
    //         "sha256"
    //       ],
    //       "signerInfo": [
    //         {
    //           "cert": {
    //             "serialNumber": "AAC5FC48C0FD8FBB",
    //             "issuerCN": "AC ABCDEF RFB v5",
    //             "issuerDN": "",
    //             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
    //             "digestAlgName": "SHA-256"
    //           },
    //           "contentType": "1.2.840.113549.1.7.1",
    //           "signingTime": "180607195054Z",
    //           "messageDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8=",
    //           "signingAlgOid": "1.2.840.113549.1.1.11",
    //           "signerDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8="
    //         },
    //         {
    //           "cert": {
    //             "serialNumber": "324FB38ABD59723F",
    //             "issuerCN": "AC ABCDEF RFB v5",
    //             "issuerDN": "",
    //             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
    //             "digestAlgName": "SHA-256"
    //           },
    //           "contentType": "1.2.840.113549.1.7.1",
    //           "signingTime": "180608182517Z",
    //           "messageDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8=",
    //           "signingAlgOid": "1.2.840.113549.1.1.11",
    //           "signerDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8="
    //         }
    //       ]
    //     }
    //   }
    // }
    // 

    int i;
    int count_i;
    const char *strVal = 0;
    const char *certSerialNumber = 0;
    const char *certIssuerCN = 0;
    const char *certIssuerDN = 0;
    const char *certDigestAlgOid = 0;
    const char *certDigestAlgName = 0;
    const char *contentType = 0;
    const char *signingTime = 0;
    const char *messageDigest = 0;
    const char *signingAlgOid = 0;
    const char *signerDigest = 0;
    CkDateTime dt;

    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);
        certSerialNumber = json->stringOf("pkcs7.verify.signerInfo[i].cert.serialNumber");
        certIssuerCN = json->stringOf("pkcs7.verify.signerInfo[i].cert.issuerCN");
        certIssuerDN = json->stringOf("pkcs7.verify.signerInfo[i].cert.issuerDN");
        certDigestAlgOid = json->stringOf("pkcs7.verify.signerInfo[i].cert.digestAlgOid");
        certDigestAlgName = json->stringOf("pkcs7.verify.signerInfo[i].cert.digestAlgName");
        contentType = json->stringOf("pkcs7.verify.signerInfo[i].contentType");
        signingTime = json->stringOf("pkcs7.verify.signerInfo[i].signingTime");

        // The signingTime isin UTCTime format.
        // UTCTime values take the form of either "YYMMDDhhmm[ss]Z" or "YYMMDDhhmm[ss](+|-)hhmm"
        // Starting in Chilkat v9.5.0.77, the SetFromTimestamp method auto-recognizes the UTCTime format and parses it correctly.
        success = dt.SetFromTimestamp(signingTime);
        // To get the signingTime in other date/time formats, look at the online reference documentation for CkDateTime.
        // There are numerous methods such as GetAsDateTime, GetAsIso8601, GetAsUnixTime, GetAsRfc822, etc.

        messageDigest = json->stringOf("pkcs7.verify.signerInfo[i].messageDigest");
        signingAlgOid = json->stringOf("pkcs7.verify.signerInfo[i].signingAlgOid");
        signerDigest = json->stringOf("pkcs7.verify.signerInfo[i].signerDigest");
        i = i + 1;
    }

    delete json;

    // println crypt.LastErrorText;
    strOut.append("Success.");
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }