tiny.reticulum.packet.proof

1const std = @import("std");2const reticulum = @import("../root.zig");34const identity = reticulum.identity;5const wire = reticulum.wire;67pub const BuildError = wire.proof.EncodeError;8/// True, so a proof carries the signature alone unless the caller asks for the9/// longer form, following Reticulum@1.5.0 RNS/Reticulum.py:262.10pub const default_implicit = true;1112/// Signs the proved packet's hash with the answering identity's private key and13/// writes the proof payload into `out`, following Reticulum@1.5.014/// RNS/Identity.py:943-953. An explicit proof carries that hash ahead of the15/// signature, and an implicit one carries the signature alone. The call returns16/// `error.OutputTooSmall` when `out` is shorter than the payload.17pub fn build(18    packet_hash: [32]u8,19    private: *const identity.Private,20    implicit: bool,21    out: []u8,22) BuildError![]u8 {23    const signature = private.sign(&packet_hash);24    const value: wire.proof.Proof = if (implicit)25        .{ .implicit = .{ .signature = signature } }26    else27        .{ .explicit = .{ .packet_hash = packet_hash, .signature = signature } };28    return wire.proof.encode(value, out);29}3031/// Returns the first 16 bytes of a proved packet's hash, the address a proof32/// packet carries, following Reticulum@1.5.0 RNS/Packet.py:381-384.33pub fn destinationHash(packet_hash: [32]u8) [16]u8 {34    return wire.proof.destinationHash(packet_hash);35}3637/// Builds the unencrypted HEADER_1 packet that carries a proof, addressed to38/// the first 16 bytes of the proved packet's hash and starting at zero hops,39/// following Reticulum@1.5.0 RNS/Packet.py:178-242.40pub fn makePacket(packet_hash: [32]u8, payload: []const u8) wire.Packet {41    return .{42        .ifac = 0,43        .header = .one,44        .context_flag = 0,45        .transport = .broadcast,46        .destination_type = .single,47        .packet_type = .proof,48        .hops = 0,49        .transport_id = null,50        .destination = destinationHash(packet_hash),51        .context = .none,52        .payload = payload,53    };54}5556test "Reticulum@1.5.0 RNS/Identity.py:943-953 builds both proof lengths" {57    var key_bytes: identity.KeyBytes = undefined;58    for (&key_bytes, 0..) |*byte, index| byte.* = @intCast(index + 1);59    var private = identity.Private.fromBytes(key_bytes);60    defer private.zero();61    const packet_hash: [32]u8 = @splat(0xa5);62    var out: [wire.proof.explicit_bytes]u8 = undefined;63    const implicit = try build(packet_hash, &private, true, &out);64    try std.testing.expectEqual(@as(usize, wire.proof.implicit_bytes), implicit.len);65    try std.testing.expect((try wire.proof.decode(implicit)) == .implicit);66    const explicit = try build(packet_hash, &private, false, &out);67    try std.testing.expectEqual(@as(usize, wire.proof.explicit_bytes), explicit.len);68    try std.testing.expect((try wire.proof.decode(explicit)) == .explicit);69}7071test "Reticulum@1.5.0 RNS/Packet.py:485-520 validates built proof payloads" {72    var key_bytes: identity.KeyBytes = undefined;73    for (&key_bytes, 0..) |*byte, index| byte.* = @intCast(index + 1);74    var private = identity.Private.fromBytes(key_bytes);75    defer private.zero();76    var public = private.public();77    defer public.zero();78    const packet_hash: [32]u8 = @splat(0x5a);79    var out: [wire.proof.explicit_bytes]u8 = undefined;80    var implicit_receipt = reticulum.packet.receipt.Receipt{81        .hash = packet_hash,82        .truncated = packet_hash[0..16].*,83        .destination = @splat(1),84        .sent_at = 1,85        .timeout = 12,86    };87    const implicit = try build(packet_hash, &private, default_implicit, &out);88    try std.testing.expect(implicit_receipt.validateProof(89        try wire.proof.decode(implicit),90        &public,91        2,92    ));93    var explicit_receipt = implicit_receipt;94    explicit_receipt.status = .sent;95    const explicit = try build(packet_hash, &private, false, &out);96    try std.testing.expect(explicit_receipt.validateProof(97        try wire.proof.decode(explicit),98        &public,99        3,100    ));101}102103test "Reticulum@1.5.0 RNS/Packet.py:381-384 proof destination is the hash prefix" {104    var packet_hash: [32]u8 = undefined;105    for (&packet_hash, 0..) |*byte, index| byte.* = @intCast(index);106    try std.testing.expectEqualSlices(u8, packet_hash[0..16], &destinationHash(packet_hash));107    const value = makePacket(packet_hash, "proof");108    try std.testing.expectEqual(wire.HeaderType.one, value.header);109    try std.testing.expectEqual(wire.PacketType.proof, value.packet_type);110    try std.testing.expectEqual(wire.Context.none, value.context);111    try std.testing.expectEqual(@as(u8, 0), value.hops);112}

1pub const proof = @import("proof.zig");