(C) Verify and Unwrap S/MIME, and get Information about CMS Signature

Demonstrates calling the Verify method to verify and unwrap S/MIME. The MIME is restored to the original structure that it would have originally had prior to signing. The Verify method works with both detached signatures, as well as opaque/attached signatures.

Calls LastJsonData to get information about the signature(s) that were verified.

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#include <C_CkMime.h>
#include <C_CkJsonObject.h>
#include <C_CkDtObj.h>

void ChilkatSample(void)
    {
    HCkMime mime;
    BOOL success;
    BOOL verified;
    HCkJsonObject json;
    HCkDtObj signingTime;
    HCkDtObj authAttrSigningTimeUtctime;
    const char *issuerCN;
    const char *serial;
    const char *strVal;
    const char *certSerialNumber;
    const char *certIssuerCN;
    const char *certDigestAlgOid;
    const char *certDigestAlgName;
    const char *contentType;
    const char *messageDigest;
    const char *signingAlgOid;
    const char *signingAlgName;
    const char *authAttrContentTypeName;
    const char *authAttrContentTypeOid;
    const char *authAttrSigningTimeName;
    const char *authAttrMessageDigestName;
    const char *authAttrMessageDigestDigest;
    const char *authAttr1_2_840_113549_1_9_15Der;
    const char *authAttr1_3_6_1_4_1_311_16_4Der;
    int i;
    int count_i;

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

    mime = CkMime_Create();

    // Load the signed MIME from a file...
    success = CkMime_LoadMimeFile(mime,"qa_data/mime/detached_sig.eml");
    if (success == FALSE) {
        printf("%s\n",CkMime_lastErrorText(mime));
        CkMime_Dispose(mime);
        return;
    }

    // Verify the S/MIME and restore the MIME
    // to the structure/content it had prior to signing.
    verified = CkMime_Verify(mime);
    if (verified == FALSE) {
        printf("%s\n",CkMime_lastErrorText(mime));
        CkMime_Dispose(mime);
        return;
    }

    // Examine the details of what was verified.
    json = CkMime_LastJsonData(mime);
    CkJsonObject_putEmitCompact(json,FALSE);
    printf("%s\n",CkJsonObject_emit(json));

    // The code to parse the following JSON (i.e. extract desired information) is shown below..

    // {
    //   "pkcs7": {
    //     "verify": {
    //       "certs": [
    //         {
    //           "issuerCN": "VeriSign Class 1 Public Primary Certification Authority - G3",
    //           "serial": "0702A21A85B84B659E180A6EE6F5A365"
    //         },
    //         {
    //           "issuerCN": "VeriSign Class 1 Public Primary Certification Authority - G3",
    //           "serial": "008B5B75568454850B00CFAF3848CEB1A4"
    //         },
    //         {
    //           "issuerCN": "Symantec Class 1 Individual Subscriber CA - G5",
    //           "serial": "619C55C32FF6BD1A7B7E0330D21C8F3C"
    //         }
    //       ],
    //       "digestAlgorithms": [
    //         "sha1"
    //       ],
    //       "signerInfo": [
    //         {
    //           "cert": {
    //             "serialNumber": "619C55C32FF6BD1A7B7E0330D21C8F3C",
    //             "issuerCN": "Symantec Class 1 Individual Subscriber CA - G5",
    //             "digestAlgOid": "1.3.14.3.2.26",
    //             "digestAlgName": "SHA1"
    //           },
    //           "contentType": "1.2.840.113549.1.7.1",
    //           "signingTime": "160428055000Z",
    //           "messageDigest": "2hJJVmO/jtaJV5uCKMFzIkRRvtY=",
    //           "signingAlgOid": "1.2.840.113549.1.1.1",
    //           "signingAlgName": "RSA-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": "160428055000Z"
    //             },
    //             "1.2.840.113549.1.9.4": {
    //               "name": "messageDigest",
    //               "digest": "2hJJVmO/jtaJV5uCKMFzIkRRvtY="
    //             },
    //             "1.2.840.113549.1.9.15": {
    //               "der": "MFAwCwYJYIZIAWUDBAECMAoGCCqGSIb3DQMHMA4GCCqGSIb3DQMCAgIAgDANBggqhkiG9w0DAgIBQDAHBgUrDgMCBzANBggqhkiG9w0DAgIBKA=="
    //             },
    //             "1.3.6.1.4.1.311.16.4": {
    //               "der": "MIG7MIG...7fgMw0hyPPA=="
    //             }
    //           }
    //         }
    //       ]
    //     }
    //   }
    // }

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

    signingTime = CkDtObj_Create();
    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);
        certSerialNumber = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].cert.serialNumber");
        certIssuerCN = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].cert.issuerCN");
        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");
        CkJsonObject_DtOf(json,"pkcs7.verify.signerInfo[i].signingTime",FALSE,signingTime);
        messageDigest = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].messageDigest");
        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");
        authAttr1_2_840_113549_1_9_15Der = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.15\".der");
        authAttr1_3_6_1_4_1_311_16_4Der = CkJsonObject_stringOf(json,"pkcs7.verify.signerInfo[i].authAttr.\"1.3.6.1.4.1.311.16.4\".der");
        i = i + 1;
    }

    CkJsonObject_Dispose(json);


    CkMime_Dispose(mime);
    CkDtObj_Dispose(signingTime);
    CkDtObj_Dispose(authAttrSigningTimeUtctime);

    }