Cape-implementation

Cape is a compiler analysis and transformation that soundly and automatically protects programs from cache side-channel attacks using commodity hardware transactional memory (HTM). It consists of program analysis and instrumentation techniques that identify sensitive data and code, delimit transactions, and insert code to preload sensitive data and code at the beginning of a transaction. More information can be found in our CC 2022 paper Cape: Compiler-Aided Program Transformation for HTM-Based Cache Side-Channel Defense.

This repository provides source code of the Cape implementation, which uses dependence analysis from dg. To build the code, install llvm-6.0, enable tsx support on your machine and run the following commands (root directory of the code is denoted as CAPE_ROOT)

cd CAPE_ROOT
mkdir build && cd build
cmake -DLLVM_DIR=/usr/lib/llvm-6.0/cmake .. # assuming llvm-6.0 has been installed in the default location
make -j

The directory CAPE_ROOT/samples contains five sample programs that can be used to show Cape's capability. We have marked in each program its secret variable using __attribute__((annotate("secret"))).

To use Cape to analyze and transform a sample program (for example, the array-based decison tree implementation dtree), run the following commands

cd CAPE_ROOT/samples
clang++-6.0 -emit-llvm -c dtree.c -mrtm -O3 -DUSE_TX -fno-use-cxa-atexit -o dtree.bc
CAPE_ROOT/build/tools/llvm-dg-dump dtree.bc 
clang++-6.0 dtree.bc_ac.ll -O3 -o dtree_cape

We also provide a script analyze.sh to ease the above procedure. To use the script to analyze and transform one or more programs (for example, aes and dtree), run

./analyze.sh aes dtree