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Ed25519ph Sign and Verify

See more Ed25519 Examples

Demonstrates how to create an Ed25519ph signature, and then to verify it.

Note: This example requires Chilkat v9.5.0.91 or greater.

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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();

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

    // Use the following test vector from https://www.rfc-editor.org/rfc/rfc8032#page-30

    //    -----TEST abc
    //
    //    ALGORITHM:
    //    Ed25519ph
    //
    //    SECRET KEY:
    //    833fe62409237b9d62ec77587520911e
    //    9a759cec1d19755b7da901b96dca3d42
    //
    //    PUBLIC KEY:
    //    ec172b93ad5e563bf4932c70e1245034
    //    c35467ef2efd4d64ebf819683467e2bf
    //
    //    MESSAGE (length 3 bytes):
    //    616263
    //
    //    SIGNATURE:
    //    98a70222f0b8121aa9d30f813d683f80
    //    9e462b469c7ff87639499bb94e6dae41
    //    31f85042463c2a355a2003d062adf5aa
    //    a10b8c61e636062aaad11c2a26083406

    const priv_key_hex = "833fe62409237b9d62ec77587520911e9a759cec1d19755b7da901b96dca3d42";
    const pub_key_hex = "ec172b93ad5e563bf4932c70e1245034c35467ef2efd4d64ebf819683467e2bf";

    const priv_key = try chilkat.PrivateKey.init();
    defer priv_key.deinit();
    priv_key.loadEd25519(priv_key_hex, pub_key_hex) catch {
        std.debug.print("{s}\n", .{try priv_key.getLastErrorText(alloc)});
        return;
    };

    // The data to be signed...
    const bd = try chilkat.BinData.init();
    defer bd.deinit();
    bd.appendEncoded("616263", "hex") catch {};

    const eddsa = try chilkat.EdDSA.init();
    defer eddsa.deinit();
    // Indicate we want the Ed25519ph instance.
    eddsa.setAlgorithm("Ed25519ph");

    const hex_sig = try eddsa.signBdENC(alloc, bd, "hexlower", priv_key);

    std.debug.print("signature = {s}\n", .{hex_sig});

    // The expected output is: 98a70222f0b8121aa9d30f813d683f80....

    // Verify the signature..
    const pub_key = try chilkat.PublicKey.init();
    defer pub_key.deinit();
    pub_key.loadEd25519(pub_key_hex) catch {
        std.debug.print("{s}\n", .{try pub_key.getLastErrorText(alloc)});
        return;
    };

    eddsa.verifyBdENC(bd, hex_sig, "hexlower", pub_key) catch {
        std.debug.print("{s}\n", .{try eddsa.getLastErrorText(alloc)});
        std.debug.print("Failed to verify the signature.\n", .{});
        return;
    };

    std.debug.print("The Ed25519ph signature is verified!\n", .{});
}