Java Requires Chilkat v11.0.0+

Verify a .p7m and get Algorithm Information

See more Digital Signatures Examples

Demonstrates how to verify a .p7m and then examine the algorithms used by the signature. Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Crypt2;
import com.chilkatsoft.chilkat2.JsonObject;

public class ChilkatExample {

    public static void main(String[] args) {
        // This example requires the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        Crypt2 crypt = new Crypt2();

        String inFile = "qa_data/p7m/brainpoolP256r1.p7m";
        String outFile = "qa_output/something.dat";

        // Verify and extract the signed data.
        try {
            crypt.verifyP7M(inFile, outFile);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Examine details about the signature(s)
        JsonObject json = new JsonObject();
        crypt.getLastJsonData(json);
        json.setEmitCompact(false);
        System.out.println(json.emit());

        // Sample output

        // {
        //   "pkcs7": {
        //     "verify": {
        //       "digestAlgorithms": [
        //         "sha256"
        //       ],
        //       "signerInfo": [
        //         {
        //           "cert": {
        //             "serialNumber": "FFFFE552B302FFFFFF1E34C3ACEB2FFFF",
        //             "issuerCN": "The common name of the cert...",
        //             "issuerDN": "",
        //             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
        //             "digestAlgName": "SHA256"
        //           },
        //           "contentType": "1.2.840.113549.1.7.1",
        //           "signingTime": "190409140500Z",
        //           "messageDigest": "lQe9If7vZKFf/NlSYu5Esmlw3phVK/RFsbbb1uH73t8=",
        //           "signingAlgOid": "1.2.840.10045.4.3.2",
        //           "signerDigest": "lQe9If7vZKFf/NlSYu5Esmlw3phVK/RFsbbb1uH73t8=",
        //           "authAttr": [
        //             {
        //               "oid": "1.2.840.113549.1.9.3",
        //               "oidName": "contentType"
        //             },
        //             {
        //               "oid": "1.2.840.113549.1.9.5",
        //               "oidName": "signingTime"
        //             },
        //             {
        //               "oid": "1.2.840.113549.1.9.52",
        //               "oidName": "1.2.840.113549.1.9.52",
        //               "der": "MBs ... AwI="
        //             },
        //             {
        //               "oid": "1.2.840.113549.1.9.4",
        //               "oidName": "messageDigest"
        //             },
        //             {
        //               "oid": "1.2.840.113549.1.9.16.2.47",
        //               "oidName": "signingCertificateV2",
        //               "der": "MCYw .. 7PlQ=="
        //             },
        //             {
        //               "oid": "1.2.840.113549.1.9.20",
        //               "oidName": "1.2.840.113549.1.9.20"
        //             }
        //           ]
        //         }
        //       ]
        //     }
        //   }
        // }

        // Code for parsing the above JSON...
        String strVal = "";
        String certSerialNumber = "";
        String certIssuerCN = "";
        String certIssuerDN = "";
        String certDigestAlgOid = "";
        String certDigestAlgName = "";
        String contentType = "";
        String signingTime = "";
        String messageDigest = "";
        String signingAlgOid = "";
        String signerDigest = "";
        int j = 0;
        int count_j = 0;
        String oid = "";
        String oidName = "";
        String der = "";

        int i = 0;
        int count_i = json.sizeOfArray("pkcs7.verify.digestAlgorithms");
        while (i < count_i) {
            json.setI(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.setI(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");
            messageDigest = json.stringOf("pkcs7.verify.signerInfo[i].messageDigest");
            signingAlgOid = json.stringOf("pkcs7.verify.signerInfo[i].signingAlgOid");
            signerDigest = json.stringOf("pkcs7.verify.signerInfo[i].signerDigest");
            j = 0;
            count_j = json.sizeOfArray("pkcs7.verify.signerInfo[i].authAttr");
            while (j < count_j) {
                json.setJ(j);
                oid = json.stringOf("pkcs7.verify.signerInfo[i].authAttr[j].oid");
                oidName = json.stringOf("pkcs7.verify.signerInfo[i].authAttr[j].oidName");
                der = json.stringOf("pkcs7.verify.signerInfo[i].authAttr[j].der");
                j = j + 1;
            }

            i = i + 1;
        }

        System.out.println("Success!");
    }
}