Clone this repository:
git clone --recurse-submodules https://github.com/chifflier/wasm-suricata.git
cd suricata
git clone -b 0.5.x https://github.com/OISF/libhtp.git
Build and install suricata as usual::
cd suricata
./autogen.sh
./configure --enable-wasm
make
See Suricata's documentation for other build options, and how to install suricata.
See the module documentation
wasm-pack build --release
cp pkg/wasm_tls_parser_bg.wasm /etc/suricata/wasm-output/
More documentation in the Wiki