-
Notifications
You must be signed in to change notification settings - Fork 0
Footprint
wolfNanoTLS's whole TLS 1.3 client .text, measured on Cortex-M33 (Thumb2,
arm-none-eabi-gcc -Os -flto -ffunction-sections -fdata-sections -Wl,--gc-sections + nano specs, ArmGNU 14.2). Each row builds from a public
configs/ starter template, so the numbers reproduce from the same
user_settings.h a deployment ships.
| Client | config | .text |
|---|---|---|
| PSK + ECDHE, X25519 | user_settings_minimal.h |
18000 (17.6 KB) |
| PSK + ECDHE, P-256 | user_settings_psk_p256.h |
25840 (25.2 KB) |
| PSK + X25519MLKEM768 (PQC) | user_settings_pqc.h |
33664 (32.9 KB) |
| cert / X.509, P-256 | user_settings_cert.h |
62297 (60.8 KB) |
| cert / X.509 + ML-DSA-44 (PQC) | user_settings_cert_mldsa.h |
81166 (79.3 KB) |
Reproduce: sh bench/footprint-clients.sh (wolfNanoTLS column).
The PQC PSK client adds ~15 KB over the classical X25519 client for the
ML-KEM-768 lattice math plus SHA-3/SHAKE (the same wc_mlkem code wolfSSL
ships). The ML-DSA-44 cert client (ECDHE P-256 + ML-DSA-44 verify, no RSA) is
the one row built without -flto: wc_mldsa.c trips an LTO + --gc-sections
live-code-removal bug in ArmGNU 14.2, so it slightly over-states versus the
-flto rows.
Code size is static, so the on-target crypto floor can be measured on the host
by cross-compiling for Thumb2 and running size (no device needed):
make floor-thumb2 # cross-compile the floor for Cortex-M33
arm-none-eabi-size -t build/thumb2/*.oThe default floor (all curves + ASN + both SP backends, pre---gc-sections)
sums to ~250 KB .text as an upper bound. The shippable number is much
smaller: roughly 40% is optional adders (X.509/ASN ~50 KB, Ed25519 group ops
~49 KB) a minimal PSK/ECDHE-P256 build does not link, and --gc-sections drops
the unreferenced remainder. A minimal TLS 1.3 floor (ECDHE-P256 + AES-GCM +
SHA-256 + HKDF + DRBG) lands far lower.
| Build | flash + RAM budget | device classes |
|---|---|---|
| PSK (17 KB) | ~17 KB flash, ~8-16 KB RAM | Cortex-M0+/M3/M4 from ~32 KB flash: LoRaWAN/NB-IoT/Matter sensors, wearables (STM32L0/L4, nRF52) |
| cert (60 KB) | ~60 KB flash, ~24-40 KB RAM | Cortex-M4/M33 from ~128 KB flash: cloud-IoT endpoints, gateways (STM32L4/U5/H5, nRF53, ESP32) |
The key-exchange floor knob is X25519 (smallest); set
WOLFNANO_HAVE_ECDHE_P256 (or WOLFNANO_FIPS) for the P-256 build. PQC and asm
add flash on top of the classical floor.
A size comparison against stock/hard-minimized mbedTLS and full wolfSSL is in Comparison.