(C) 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.

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#include <C_CkBinData.h>
#include <C_CkCrypt2.h>
#include <C_CkJsonObject.h>
#include <C_CkDateTime.h>

void ChilkatSample(void)
    {
    HCkBinData bd;
    BOOL success;
    HCkCrypt2 crypt;
    HCkJsonObject json;
    int i;
    int count_i;
    const char *strVal;
    const char *certSerialNumber;
    const char *certIssuerCN;
    const char *certIssuerDN;
    const char *certDigestAlgOid;
    const char *certDigestAlgName;
    const char *contentType;
    const char *signingTime;
    const char *messageDigest;
    const char *signingAlgOid;
    const char *signerDigest;
    HCkDateTime dt;

    // 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..
    bd = CkBinData_Create();
    success = CkBinData_LoadFile(bd,"qa_data/p7s/sample.p7s");
    if (success != TRUE) {
        printf("Failed to load .p7s file.\n");
        CkBinData_Dispose(bd);
        return;
    }

    // IMPORTANT:  This example requires Chilkat v9.5.0.75 or greater.
    crypt = CkCrypt2_Create();

    // Assuming this is a signature that contains the original data that was signed..
    success = CkCrypt2_OpaqueVerifyBd(crypt,bd);
    if (success != TRUE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkBinData_Dispose(bd);
        CkCrypt2_Dispose(crypt);
        return;
    }

    // Examine the LastJsonData after signature verification..
    json = CkCrypt2_LastJsonData(crypt);
    CkJsonObject_putEmitCompact(json,FALSE);
    printf("%s\n",CkJsonObject_emit(json));

    // --
    // 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="
    //         }
    //       ]
    //     }
    //   }
    // }
    // 

    dt = CkDateTime_Create();

    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);
        certSerialNumber = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].cert.serialNumber");
        certIssuerCN = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].cert.issuerCN");
        certIssuerDN = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].cert.issuerDN");
        certDigestAlgOid = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].cert.digestAlgOid");
        certDigestAlgName = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].cert.digestAlgName");
        contentType = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].contentType");
        signingTime = CkJsonObject_stringOf(json,"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 = CkDateTime_SetFromTimestamp(dt,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 = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].messageDigest");
        signingAlgOid = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].signingAlgOid");
        signerDigest = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].signerDigest");
        i = i + 1;
    }

    CkJsonObject_Dispose(json);

    // println crypt.LastErrorText;
    printf("Success.\n");


    CkBinData_Dispose(bd);
    CkCrypt2_Dispose(crypt);
    CkDateTime_Dispose(dt);

    }