Zig 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. Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

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

    const crypt = try chilkat.Crypt2.init();
    defer crypt.deinit();

    const in_file = "qa_data/p7m/brainpoolP256r1.p7m";
    const out_file = "qa_output/something.dat";

    // Verify and extract the signed data.
    crypt.verifyP7M(in_file, out_file) catch {
        std.debug.print("{s}\n", .{try crypt.getLastErrorText(alloc)});
        return;
    };

    // Examine details about the signature(s)
    const json = try chilkat.JsonObject.init();
    defer json.deinit();
    crypt.getLastJsonData(json);
    json.setEmitCompact(false);
    std.debug.print("{s}\n", .{try json.emit(alloc)});

    // 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...
    var i: i32 = 0;
    var count_i: i32 = 0;
    var str_val: [:0]const u8 = "";
    var cert_serial_number: [:0]const u8 = "";
    var cert_issuer_cn: [:0]const u8 = "";
    var cert_issuer_dn: [:0]const u8 = "";
    var cert_digest_alg_oid: [:0]const u8 = "";
    var cert_digest_alg_name: [:0]const u8 = "";
    var content_type: [:0]const u8 = "";
    var signing_time: [:0]const u8 = "";
    var message_digest: [:0]const u8 = "";
    var signing_alg_oid: [:0]const u8 = "";
    var signer_digest: [:0]const u8 = "";
    var j: i32 = 0;
    var count_j: i32 = 0;
    var oid: [:0]const u8 = "";
    var oid_name: [:0]const u8 = "";
    var der: [:0]const u8 = "";

    i = 0;
    count_i = json.sizeOfArray("pkcs7.verify.digestAlgorithms");
    while (i < count_i) {
        json.setI(i);
        str_val = try json.stringOf(alloc, "pkcs7.verify.digestAlgorithms[i]");
        i = i + 1;
    }

    i = 0;
    count_i = json.sizeOfArray("pkcs7.verify.signerInfo");
    while (i < count_i) {
        json.setI(i);
        cert_serial_number = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].cert.serialNumber");
        cert_issuer_cn = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].cert.issuerCN");
        cert_issuer_dn = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].cert.issuerDN");
        cert_digest_alg_oid = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].cert.digestAlgOid");
        cert_digest_alg_name = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].cert.digestAlgName");
        content_type = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].contentType");
        signing_time = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].signingTime");
        message_digest = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].messageDigest");
        signing_alg_oid = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].signingAlgOid");
        signer_digest = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].signerDigest");
        j = 0;
        count_j = json.sizeOfArray("pkcs7.verify.signerInfo[i].authAttr");
        while (j < count_j) {
            json.setJ(j);
            oid = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].authAttr[j].oid");
            oid_name = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].authAttr[j].oidName");
            der = try json.stringOf(alloc, "pkcs7.verify.signerInfo[i].authAttr[j].der");
            j = j + 1;
        }

        i = i + 1;
    }

    std.debug.print("Success!\n", .{});
}