#!/usr/bin/env bash
# ─────────────────────────────────────────────────────────────
#  capture_tls.sh - Capture TLS ClientHello fingerprints (JA3)
#
#  mitmproxy terminates TLS so it can't see the real JA3 that
#  Claude CLI / Antigravity sends to Anthropic. This script
#  captures the REAL TLS fingerprint using tshark.
#
#  Usage:
#    # Run BEFORE starting claude login / claude "hello"
#    # (don't use HTTPS_PROXY for this - direct connection)
#
#    sudo ./capture_tls.sh              # capture on default interface
#    sudo ./capture_tls.sh en0          # specify interface
#    sudo ./capture_tls.sh en0 30       # capture for 30 seconds
#
#  Output:
#    ./captures/tls_capture_<timestamp>.txt
#    ./captures/tls_capture_<timestamp>.pcap
# ─────────────────────────────────────────────────────────────

set -euo pipefail

IFACE="${1:-en0}"
DURATION="${2:-60}"
OUTDIR="./captures"
TIMESTAMP=$(date +%Y%m%d_%H%M%S)
PCAP_FILE="${OUTDIR}/tls_capture_${TIMESTAMP}.pcap"
TXT_FILE="${OUTDIR}/tls_capture_${TIMESTAMP}.txt"

mkdir -p "$OUTDIR"

# Resolve target IPs
echo "Resolving target domains..."
DOMAINS=(
    "api.anthropic.com"
    "platform.claude.com"
    "claude.ai"
    "cloudaicompanion.googleapis.com"
    "generativelanguage.googleapis.com"
    "oauth2.googleapis.com"
    "accounts.google.com"
)

HOST_FILTER=""
for domain in "${DOMAINS[@]}"; do
    ips=$(dig +short "$domain" 2>/dev/null | grep -E '^[0-9]+\.' | head -5)
    for ip in $ips; do
        if [ -n "$HOST_FILTER" ]; then
            HOST_FILTER="$HOST_FILTER or host $ip"
        else
            HOST_FILTER="host $ip"
        fi
    done
    echo "  $domain → $ips"
done

if [ -z "$HOST_FILTER" ]; then
    echo "ERROR: Could not resolve any target domains"
    exit 1
fi

CAPTURE_FILTER="tcp port 443 and ($HOST_FILTER)"

echo ""
echo "═══════════════════════════════════════════════════════"
echo "  TLS Fingerprint Capture"
echo "  Interface:  $IFACE"
echo "  Duration:   ${DURATION}s"
echo "  Filter:     $CAPTURE_FILTER"
echo "  PCAP:       $PCAP_FILE"
echo "  Report:     $TXT_FILE"
echo "═══════════════════════════════════════════════════════"
echo ""
echo ">>> Now run 'claude login' or 'claude \"hello\"' in another terminal <<<"
echo ">>> Press Ctrl+C to stop early <<<"
echo ""

# Capture pcap in background
tshark -i "$IFACE" -f "$CAPTURE_FILTER" -w "$PCAP_FILE" -a "duration:$DURATION" 2>/dev/null &
TSHARK_PID=$!

# Wait for capture to complete or Ctrl+C
trap "kill $TSHARK_PID 2>/dev/null; wait $TSHARK_PID 2>/dev/null" INT TERM
wait $TSHARK_PID 2>/dev/null || true

echo ""
echo "Capture complete. Analyzing..."
echo ""

# ─── Analysis ───

{
    echo "═══════════════════════════════════════════════════════"
    echo "  TLS ClientHello Fingerprint Report"
    echo "  Captured: $(date)"
    echo "  PCAP: $PCAP_FILE"
    echo "═══════════════════════════════════════════════════════"
    echo ""

    # Extract JA3 fingerprints
    echo "─── JA3 Fingerprints (ClientHello) ───"
    echo ""
    tshark -r "$PCAP_FILE" \
        -Y "tls.handshake.type == 1" \
        -T fields \
        -e frame.time \
        -e ip.dst \
        -e tls.handshake.extensions_server_name \
        -e tls.handshake.ja3 \
        -e tls.handshake.ja3_full \
        2>/dev/null | while IFS=$'\t' read -r ts dst sni ja3 ja3_full; do
            echo "  Time:     $ts"
            echo "  Dest IP:  $dst"
            echo "  SNI:      $sni"
            echo "  JA3 Hash: $ja3"
            if [ -n "$ja3_full" ]; then
                echo "  JA3 Full: $ja3_full"
            fi
            echo ""
        done

    echo ""
    echo "─── TLS Versions ───"
    echo ""
    tshark -r "$PCAP_FILE" \
        -Y "tls.handshake.type == 1" \
        -T fields \
        -e tls.handshake.extensions_server_name \
        -e tls.handshake.version \
        -e tls.handshake.extensions.supported_version \
        2>/dev/null | sort -u | while IFS=$'\t' read -r sni ver supported; do
            echo "  SNI: $sni"
            echo "    Record Version:    $ver"
            echo "    Supported Versions: $supported"
            echo ""
        done

    echo ""
    echo "─── ALPN Protocols ───"
    echo ""
    tshark -r "$PCAP_FILE" \
        -Y "tls.handshake.type == 1" \
        -T fields \
        -e tls.handshake.extensions_server_name \
        -e tls.handshake.extensions_alpn_str \
        2>/dev/null | sort -u | while IFS=$'\t' read -r sni alpn; do
            echo "  SNI: $sni → ALPN: $alpn"
        done

    echo ""
    echo ""
    echo "─── Cipher Suites (per ClientHello) ───"
    echo ""
    tshark -r "$PCAP_FILE" \
        -Y "tls.handshake.type == 1" \
        -T fields \
        -e tls.handshake.extensions_server_name \
        -e tls.handshake.ciphersuite \
        2>/dev/null | head -5 | while IFS=$'\t' read -r sni ciphers; do
            echo "  SNI: $sni"
            echo "  Cipher Suites:"
            echo "    $ciphers" | tr ',' '\n' | while read -r c; do
                echo "    $c"
            done
            echo ""
        done

    echo ""
    echo "─── Extensions (per ClientHello) ───"
    echo ""
    tshark -r "$PCAP_FILE" \
        -Y "tls.handshake.type == 1" \
        -T fields \
        -e tls.handshake.extensions_server_name \
        -e tls.handshake.extension.type \
        2>/dev/null | head -5 | while IFS=$'\t' read -r sni exts; do
            echo "  SNI: $sni"
            echo "  Extensions: $exts"
            echo ""
        done

    echo ""
    echo "─── Unique JA3 Summary ───"
    echo ""
    tshark -r "$PCAP_FILE" \
        -Y "tls.handshake.type == 1" \
        -T fields \
        -e tls.handshake.extensions_server_name \
        -e tls.handshake.ja3 \
        2>/dev/null | sort | uniq -c | sort -rn | while read -r count sni ja3; do
            echo "  ${count}x  SNI: $sni  JA3: $ja3"
        done

    echo ""
    echo "─── TCP Fingerprint (Initial Window Size, TTL) ───"
    echo ""
    tshark -r "$PCAP_FILE" \
        -Y "tcp.flags.syn == 1 && tcp.flags.ack == 0" \
        -T fields \
        -e ip.dst \
        -e ip.ttl \
        -e tcp.window_size_value \
        -e tcp.options.mss_val \
        -e tcp.options.wscale.shift \
        2>/dev/null | sort -u | while IFS=$'\t' read -r dst ttl win mss wscale; do
            echo "  Dest: $dst  TTL: $ttl  Window: $win  MSS: $mss  WScale: $wscale"
        done

} 2>/dev/null | tee "$TXT_FILE"

echo ""
echo "═══════════════════════════════════════════════════════"
echo "  Report saved to: $TXT_FILE"
echo "  PCAP saved to:   $PCAP_FILE"
echo ""
echo "  To re-analyze:   tshark -r $PCAP_FILE -Y 'tls.handshake.type==1' ..."
echo "═══════════════════════════════════════════════════════"