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Load ECC Public Key from JWK Format (JSON Web Key)

See more ECC Examples

Demonstrates how to load an ECC public key from JWK (JSON Web Key) format.

Note: This example requires Chilkat v9.5.0.66 or later.

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

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

    // Note: This example requires Chilkat v9.5.0.66 or later.

    // First build a JWK sample to load..
    const json = try chilkat.JsonObject.init();
    defer json.deinit();
    json.updateString("kty", "EC") catch {};
    json.updateString("crv", "P-256") catch {};
    json.updateString("x", "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE") catch {};
    json.updateString("y", "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU") catch {};

    // The JSON contains the following:
    // {
    //   "kty": "EC",
    //   "crv": "P-256",
    //   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
    //   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
    // }

    // Note: The JSON can contain other members, such as "use", "kid", or anything else.  These will be ignored.
    json.setEmitCompact(false);

    // Show the JWK string to be loaded:
    const jwk_str = try json.emit(alloc);

    const pub_key = try chilkat.PublicKey.init();
    defer pub_key.deinit();
    // The LoadFromString method will automatically detect the format.
    pub_key.loadFromString(jwk_str) catch {
        std.debug.print("{s}\n", .{try pub_key.getLastErrorText(alloc)});
        return;
    };

    // OK.. the JWK is loaded.  It can be used in whatever way desired...

    // The key can be retrieved in any other format, such as XML or PEM..
    std.debug.print("{s}\n", .{try pub_key.getXml(alloc)});

    // XML output:
    // <ECCPublicKey curve="secp256r1"
    //    x="A01532A3C0900053DE60FBEFEFCCA58793301598D308B41E6F4E364E388C2711"
    //    y="BEF432C599148C94143D4FF46C2CB73E3E6A41D7EEF23C047EA11E60667DE425">
    //    MIIBSzCCAQMGByqGSM49AgEwgfcCAQEwLAYHKoZIzj0BAQIhAP////8AAAABAAAAAAAAAAAAAAAA////////////////MFsEIP////8AAAABAAAAAAAAAAAAAAAA///////////////8BCBaxjXYqjqT57PrvVV2mIa8ZR0GsMxTsPY7zjw+J9JgSwMVAMSdNgiG5wSTamZ44ROdJreBn36QBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt6zOg9KE5RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA//////////+85vqtpxeehPO5ysL8YyVRAgEBA0IABKAVMqPAkABT3mD77+/MpYeTMBWY0wi0Hm9ONk44jCcRvvQyxZkUjJQUPU/0bCy3Pj5qQdfu8jwEfqEeYGZ95CU=
    // </ECCPublicKey>

    // Choose PCKS1 or PCKS8 PEM format..
    const b_prefer_pkcs1 = false;
    std.debug.print("{s}\n", .{try pub_key.getPem(alloc, b_prefer_pkcs1)});

    // PEM output
    // -----BEGIN PUBLIC KEY-----
    // MIIBSzCCAQMGByqGSM49AgEwgfcCAQEwLAYHKoZIzj0BAQIhAP////8AAAABAAAA
    // AAAAAAAAAAAA////////////////MFsEIP////8AAAABAAAAAAAAAAAAAAAA////
    // ///////////8BCBaxjXYqjqT57PrvVV2mIa8ZR0GsMxTsPY7zjw+J9JgSwMVAMSd
    // NgiG5wSTamZ44ROdJreBn36QBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt6zOg9KE5
    // RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA
    // //////////+85vqtpxeehPO5ysL8YyVRAgEBA0IABKAVMqPAkABT3mD77+/MpYeT
    // MBWY0wi0Hm9ONk44jCcRvvQyxZkUjJQUPU/0bCy3Pj5qQdfu8jwEfqEeYGZ95CU=
    // -----END PUBLIC KEY-----
}