Python

macOS / Linux / Windows

# 1) No-dependency check — identify this machine first.
uname -a 2>/dev/null || true

# 2) Dependency check — prompt before installing anything.
if ! command -v python3 >/dev/null 2>&1; then
  echo 'Python 3 was not found.'
  printf 'Install or enable Python 3 now? [y/N] '
  read answer
  case "$answer" in
    [Yy]*) echo 'Install Python 3 from your OS package manager or python.org, then rerun this snippet.' ;;
    *) echo 'Skipping Python 3-based check.'; exit 1 ;;
  esac
fi

# 3) Capability — fully offline. OpenSSL ≥ 3.5 = native ML-KEM.
python3 -c "import ssl; print(ssl.OPENSSL_VERSION)"

# 4) Liveness — confirm a TLS 1.3 handshake works against the target.
#    Python's ssl module has NO public API for the negotiated named group,
#    so the authoritative answer comes from the local openssl below.
python3 - <<'EOF'
import ssl, socket
ctx = ssl.create_default_context()
with socket.create_connection(("example.com", 443)) as s, \
     ctx.wrap_socket(s, server_hostname="example.com") as t:
    print("proto=", t.version(), "cipher=", t.cipher()[0])
EOF

# 5) Authoritative named-group readout — still local, via openssl CLI.
# 1) No-dependency check — identify this machine first.
uname -a 2>/dev/null || true

# 2) Dependency check — prompt before installing anything.
if ! command -v openssl >/dev/null 2>&1; then
  echo 'OpenSSL was not found. A local PQC proof needs OpenSSL 3.5+.'
  printf 'Install OpenSSL now? [y/N] '
  read answer
  case "$answer" in
    [Yy]*)
      if command -v brew >/dev/null 2>&1; then brew install openssl@3
      elif command -v apt-get >/dev/null 2>&1; then sudo apt-get update && sudo apt-get install -y openssl
      elif command -v dnf >/dev/null 2>&1; then sudo dnf install -y openssl
      elif command -v yum >/dev/null 2>&1; then sudo yum install -y openssl
      else echo 'No supported package manager found. Install OpenSSL 3.5+ and retry.'; exit 1
      fi ;;
    *) echo 'Install OpenSSL 3.5+ and retry for a local PQC proof.'; exit 1 ;;
  esac
fi

OPENSSL=openssl
if command -v brew >/dev/null 2>&1; then
  BREW_OPENSSL="$(brew --prefix openssl@3 2>/dev/null)/bin/openssl"
  [ -x "$BREW_OPENSSL" ] && OPENSSL="$BREW_OPENSSL"
fi

$OPENSSL version
if ! $OPENSSL list -tls-groups 2>/dev/null | grep -qiE 'X25519MLKEM768|MLKEM|Kyber'; then
  echo 'This OpenSSL does not advertise ML-KEM groups. Upgrade to OpenSSL 3.5+ or load oqsprovider, then retry.'
  exit 1
fi
$OPENSSL s_client -connect example.com:443 -tls1_3 -groups X25519MLKEM768   </dev/null 2>&1 | grep -E 'Negotiated TLS1\.3 group|Server Temp Key'

OpenSSL 3.5.0 8 Apr 2025
proto= TLSv1.3 cipher= TLS_AES_256_GCM_SHA384
Negotiated TLS1.3 group: X25519MLKEM768

OpenSSL 3.0.13 30 Jan 2024
proto= TLSv1.3 cipher= TLS_AES_256_GCM_SHA384
# (no group line)

To make Python applications actively SEND the PQ group, configure it in /etc/ssl/openssl.cnf (Groups = X25519MLKEM768:…) — ssl.SSLContext has no Python-level setter for the groups list. macOS system Python links LibreSSL (no ML-KEM); use brew python@3.13 + openssl@3.