2020-10-27 04:18:44 +08:00
|
|
|
const std = @import("std");
|
|
|
|
const assert = std.debug.assert;
|
|
|
|
|
|
|
|
const segfault = true;
|
|
|
|
|
|
|
|
pub const JournalHeader = packed struct {
|
|
|
|
hash_chain_root: u128 = undefined,
|
|
|
|
prev_hash_chain_root: u128,
|
|
|
|
checksum: u128 = undefined,
|
|
|
|
magic: u64,
|
|
|
|
command: u32,
|
|
|
|
size: u32,
|
|
|
|
|
|
|
|
pub fn calculate_checksum(self: *const JournalHeader, entry: []const u8) u128 {
|
|
|
|
assert(entry.len >= @sizeOf(JournalHeader));
|
|
|
|
assert(entry.len == self.size);
|
|
|
|
|
2021-06-11 04:56:55 +08:00
|
|
|
const checksum_offset = @offsetOf(JournalHeader, "checksum");
|
2020-10-27 04:18:44 +08:00
|
|
|
const checksum_size = @sizeOf(@TypeOf(self.checksum));
|
|
|
|
assert(checksum_offset == 0 + 16 + 16);
|
|
|
|
assert(checksum_size == 16);
|
|
|
|
|
|
|
|
var target: [32]u8 = undefined;
|
|
|
|
std.crypto.hash.Blake3.hash(entry[checksum_offset + checksum_size ..], target[0..], .{});
|
|
|
|
return @bitCast(u128, target[0..checksum_size].*);
|
|
|
|
}
|
|
|
|
|
|
|
|
pub fn calculate_hash_chain_root(self: *const JournalHeader) u128 {
|
|
|
|
const hash_chain_root_size = @sizeOf(@TypeOf(self.hash_chain_root));
|
|
|
|
assert(hash_chain_root_size == 16);
|
|
|
|
|
2021-06-11 04:56:55 +08:00
|
|
|
const prev_hash_chain_root_offset = @offsetOf(JournalHeader, "prev_hash_chain_root");
|
2020-10-27 04:18:44 +08:00
|
|
|
const prev_hash_chain_root_size = @sizeOf(@TypeOf(self.prev_hash_chain_root));
|
|
|
|
assert(prev_hash_chain_root_offset == 0 + 16);
|
|
|
|
assert(prev_hash_chain_root_size == 16);
|
|
|
|
|
2021-06-11 04:56:55 +08:00
|
|
|
const checksum_offset = @offsetOf(JournalHeader, "checksum");
|
2020-10-27 04:18:44 +08:00
|
|
|
const checksum_size = @sizeOf(@TypeOf(self.checksum));
|
|
|
|
assert(checksum_offset == 0 + 16 + 16);
|
|
|
|
assert(checksum_size == 16);
|
|
|
|
|
|
|
|
assert(prev_hash_chain_root_offset + prev_hash_chain_root_size == checksum_offset);
|
|
|
|
|
|
|
|
const header = @bitCast([@sizeOf(JournalHeader)]u8, self.*);
|
|
|
|
const source = header[prev_hash_chain_root_offset .. checksum_offset + checksum_size];
|
|
|
|
assert(source.len == prev_hash_chain_root_size + checksum_size);
|
|
|
|
var target: [32]u8 = undefined;
|
|
|
|
std.crypto.hash.Blake3.hash(source, target[0..], .{});
|
|
|
|
if (segfault) {
|
|
|
|
return @bitCast(u128, target[0..hash_chain_root_size].*);
|
|
|
|
} else {
|
|
|
|
var array = target[0..hash_chain_root_size].*;
|
|
|
|
return @bitCast(u128, array);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
pub fn set_checksum_and_hash_chain_root(self: *JournalHeader, entry: []const u8) void {
|
|
|
|
self.checksum = self.calculate_checksum(entry);
|
|
|
|
self.hash_chain_root = self.calculate_hash_chain_root();
|
|
|
|
}
|
|
|
|
};
|
|
|
|
|
|
|
|
test "fixed" {
|
|
|
|
var buffer = [_]u8{0} ** 65536;
|
|
|
|
var entry = std.mem.bytesAsValue(JournalHeader, buffer[0..@sizeOf(JournalHeader)]);
|
|
|
|
entry.* = .{
|
|
|
|
.prev_hash_chain_root = 0,
|
|
|
|
.magic = 0,
|
|
|
|
.command = 0,
|
|
|
|
.size = 64 + 128,
|
|
|
|
};
|
|
|
|
entry.set_checksum_and_hash_chain_root(buffer[0..entry.size]);
|
|
|
|
try std.io.null_writer.print("{}\n", .{entry});
|
|
|
|
}
|