Akirayasha/relbench_O2

RelBench-O2: Constant-Time Assembly at -O2

Overview

This dataset collects the rel_bench constant-time programs, re-cut into one self-contained program per record, compiled with LLVM/Clang-17 at -O2 for three targets, and checked for constant-timeness with binsec -sse -checkct.

Constant-time source code is not enough: the optimizer can reintroduce a secret-dependent branch or memory access that the -O0 build does not have, and it does so differently per target. The intended tasks are transpilation (translate the assembly to another ISA) and classification/repair (decide whether a build leaks, and fix it if it does).

Dataset Structure

Column	Description
task_name	Sample identifier, e.g. ct_select_1
flag_x86_64	BinSec constant-time verdict for the x86-64 -O2 build: secure, insecure, or unknown
flag_aarch64_linux	Same, for the AArch64 -O2 build
flag_riscv	Same, for the RISC-V -O2 build
x86_64	x86-64 assembly at -O2 (Intel syntax, built with -masm=intel)
aarch64_linux	AArch64 assembly at -O2
riscv	RISC-V RV64 (rv64gc/lp64d) assembly at -O2
test_c	C source of the BinSec harness (test.c) -- tags inputs secret/public through the high_input_N / low_input_N markers and calls the function under analysis
binsec_output_x86_64	Full binsec -checkct log for the x86-64 -O2 build -- the evidence flag_x86_64 was parsed from, including the leaking instruction addresses
binsec_output_aarch64_linux	Same, for the AArch64 -O2 build
binsec_output_riscv	Same, for the RISC-V -O2 build

Statistics

• Total records: 36

column	secure	insecure	unknown
flag_x86_64	31	5	0
flag_aarch64_linux	34	2	0
flag_riscv	29	7	0

The constant-time oracle

Each build is analysed by BinSec's checkct plugin:

binsec -sse -checkct -sse-script "libsym.ini,checkct.cfg" -sse-depth 50000 test_bin

libsym.ini replaces the high_input_N markers with secret and the low_input_N markers with nondet (public), so BinSec knows which bytes are secret. It then reports:

• secure -- no control flow or memory access depends on a secret
• insecure -- at least one secret-dependent branch or address was found
• unknown -- BinSec could not decide (path cut, depth limit, unresolved symbol)

The verdict is per build. The same program can be secure on one target and insecure on another, because the three backends make different branch/cmov/csel choices at -O2. That is why the verdict is not collapsed into one label: each target carries its own flag_* column, with the full analysis log in the matching binsec_output_* column -- that log names the control-flow and memory-access checks that failed and at which addresses, so an insecure verdict can be traced back to a specific instruction.

Usage

from datasets import load_dataset

ds = load_dataset("Akirayasha/relbench_O2", split="test")

record = ds[0]
src_asm = record["x86_64"]  # source-side assembly
tgt_asm = record["riscv"]   # reference target-side assembly
leaky   = record["flag_riscv"] == "insecure"   # per-target verdict
harness = record["test_c"]  # rebuild + recheck a candidate against BinSec
why     = record["binsec_output_riscv"]  # the BinSec log behind flag_riscv

Citation

Part of the CISC-to-RISC transpilation research project at MBZUAI.