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Get ECC Public Key in JWK Format (JSON Web Key)

See more ECC Examples

Demonstrates how to get an ECC public key in 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.

    // Load a PEM file into memory.
    const sb_pem = try chilkat.StringBuilder.init();
    defer sb_pem.deinit();
    sb_pem.loadFile("qa_data/pem/ecc_public.pem", "utf-8") catch {
        std.debug.print("Failed to load PEM file.\n", .{});
        return;
    };

    // Load the PEM into a public key object.
    const pub_key = try chilkat.PublicKey.init();
    defer pub_key.deinit();
    pub_key.loadFromString(try sb_pem.getAsString(alloc)) catch {
        std.debug.print("{s}\n", .{try pub_key.getLastErrorText(alloc)});
        return;
    };

    // Get the public key in JWK format:
    const jwk = try pub_key.getJwk(alloc);

    // The GetJwk method will return the JWK in the most compact JSON format possible,
    // as a single line with no extra whitespace.  To get a more human-readable JWK (for this example),
    // load into a Chilkat JSON object and emit non-compact:

    const json = try chilkat.JsonObject.init();
    defer json.deinit();
    json.load(jwk) catch {};
    json.setEmitCompact(false);
    std.debug.print("ECC Public Key in JWK format:\n", .{});
    std.debug.print("{s}\n", .{try json.emit(alloc)});

    // Sample output:
    // {
    //   "kty": "EC",
    //   "crv": "P-256",
    //   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
    //   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU"
    // }
    //
    // Additional information can be added like this:
    json.appendString("use", "enc") catch {};
    json.appendString("kid", "123ABC") catch {};

    // Now examine the JSON:
    std.debug.print("{s}\n", .{try json.emit(alloc)});

    // {
    //   "kty": "EC",
    //   "crv": "P-256",
    //   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
    //   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
    //   "use": "enc",
    //   "kid": "123ABC"
    // }
}