Add script to convert MeshCore firmware key to pyMC_Repeater seed format

convert_firmware_key.sh

@@ -0,0 +1,167 @@
+#!/bin/bash
+# Convert MeshCore firmware 64-byte private key to pyMC_Repeater 32-byte seed format
+#
+# Usage: sudo ./convert_firmware_key.sh <64-byte-hex-key> [config-path]
+# Example: sudo ./convert_firmware_key.sh 681b98730e826d3140f9ac02e94e3de14163418a4a8e069bf8c6fb275bf07e6a7c05b788f5eba746ab0deb613b7502ee316346f7886fbfde56180d3aaaa98033
+
+set -e
+
+if [ $# -eq 0 ]; then
+    echo "Error: No key provided"
+    echo ""
+    echo "Usage: sudo $0 <64-byte-hex-key> [config-path]"
+    echo ""
+    echo "This script converts a 64-byte MeshCore firmware private key to the"
+    echo "32-byte seed format used by pyMC_Repeater and updates config.yaml."
+    echo ""
+    echo "The 64-byte key is SHA-512(seed), where:"
+    echo "  - First 32 bytes: Ed25519 scalar (used for public key derivation)"
+    echo "  - Last 32 bytes: Nonce seed (used for signature generation)"
+    echo ""
+    echo "IMPORTANT: The conversion is ONE-WAY. You cannot recover the original"
+    echo "seed from the 64-byte key. This script extracts the scalar portion."
+    echo ""
+    echo "Arguments:"
+    echo "  config-path: Optional path to config.yaml (default: /etc/pymc_repeater/config.yaml)"
+    echo ""
+    echo "Example:"
+    echo "  sudo $0 681b98730e826d3140f9ac02e94e3de14163418a4a8e069bf8c6fb275bf07e6a7c05b788f5eba746ab0deb613b7502ee316346f7886fbfde56180d3aaaa98033"
+    exit 1
+fi
+
+# Check if running with sudo/root
+if [ "$EUID" -ne 0 ]; then
+    echo "Error: This script must be run with sudo to update config.yaml"
+    echo "Usage: sudo $0 <64-byte-hex-key>"
+    exit 1
+fi
+
+FULL_KEY="$1"
+
+# Validate hex string
+if ! [[ "$FULL_KEY" =~ ^[0-9a-fA-F]+$ ]]; then
+    echo "Error: Key must be a hexadecimal string"
+    exit 1
+fi
+
+KEY_LEN=${#FULL_KEY}
+
+if [ "$KEY_LEN" -ne 128 ]; then
+    echo "Error: Key must be 64 bytes (128 hex characters), got $KEY_LEN characters"
+    exit 1
+fi
+
+# Extract first 32 bytes (64 hex chars) - this is the Ed25519 scalar
+SEED_HEX="${FULL_KEY:0:64}"
+
+# Convert to base64 for Python repeater (using Python since xxd may not be installed)
+SEED_BASE64=$(python3 -c "import binascii, base64; print(base64.b64encode(binascii.unhexlify('$SEED_HEX')).decode())")
+
+# Get config path
+CONFIG_PATH="${2:-/etc/pymc_repeater/config.yaml}"
+
+# Check if config exists
+if [ ! -f "$CONFIG_PATH" ]; then
+    echo "Error: Config file not found: $CONFIG_PATH"
+    exit 1
+fi
+
+echo "=== MeshCore Firmware Key Conversion ==="
+echo ""
+echo "Input (64-byte firmware key):"
+echo "  Full key:    $FULL_KEY"
+echo ""
+echo "Extracted Ed25519 scalar (first 32 bytes):"
+echo "  Hex:         $SEED_HEX"
+echo "  Base64:      $SEED_BASE64"
+echo ""
+
+# Verify public key derivation
+echo "Verifying public key derivation..."
+PUBLIC_KEY=$(python3 -c "
+from nacl.bindings import crypto_scalarmult_ed25519_base
+import binascii
+seed = binascii.unhexlify('$SEED_HEX')
+pub = crypto_scalarmult_ed25519_base(seed)
+print(pub.hex())
+" 2>/dev/null)
+
+if [ $? -eq 0 ]; then
+    echo "  Public key:  $PUBLIC_KEY"
+    PUBLIC_HASH=$(python3 -c "print('0x' + '$PUBLIC_KEY'[:2])")
+    echo "  Node hash:   $PUBLIC_HASH"
+    echo ""
+else
+    echo "  Warning: Could not verify public key (PyNaCl not installed)"
+    echo ""
+fi
+
+# Check if identity_key already exists in config
+EXISTING_KEY=$(grep -E "^\s*identity_key:" "$CONFIG_PATH" 2>/dev/null || true)
+if [ -n "$EXISTING_KEY" ]; then
+    echo "WARNING: An identity_key already exists in config.yaml"
+    echo "Current: $EXISTING_KEY"
+    echo ""
+fi
+
+# Ask for confirmation
+echo "Target: $CONFIG_PATH"
+read -p "Update config.yaml with this identity key? (yes/no): " CONFIRM
+if [ "$CONFIRM" != "yes" ]; then
+    echo "Aborted."
+    exit 0
+fi
+
+# Create backup
+BACKUP_PATH="${CONFIG_PATH}.backup.$(date +%Y%m%d_%H%M%S)"
+cp "$CONFIG_PATH" "$BACKUP_PATH"
+echo "Created backup: $BACKUP_PATH"
+
+# Update config.yaml
+# First, try to update existing identity_key (commented or not)
+if grep -qE "^\s*#?\s*identity_key:" "$CONFIG_PATH"; then
+    # Replace existing identity_key line
+    sed -i.tmp "/^\s*#\?\s*identity_key:/c\  identity_key: !!binary |\n    $SEED_BASE64" "$CONFIG_PATH"
+    # Clean up any orphaned base64 value lines from old commented key
+    sed -i.tmp '/^\s*#\s*[A-Za-z0-9+/=]\{40,\}$/d' "$CONFIG_PATH"
+    rm -f "${CONFIG_PATH}.tmp"
+    echo "✓ Updated existing identity_key in config.yaml"
+else
+    # Add identity_key to mesh section
+    if grep -q "^mesh:" "$CONFIG_PATH"; then
+        # Insert after mesh: line
+        sed -i.tmp "/^mesh:/a\  identity_key: !!binary |\n    $SEED_BASE64" "$CONFIG_PATH"
+        rm -f "${CONFIG_PATH}.tmp"
+        echo "✓ Added identity_key to mesh section in config.yaml"
+    else
+        echo "Error: Could not find 'mesh:' section in config.yaml"
+        echo "Please add manually:"
+        echo ""
+        echo "mesh:"
+        echo "  identity_key: !!binary |"
+        echo "    $SEED_BASE64"
+        exit 1
+    fi
+fi
+
+echo ""
+echo "✓ Successfully updated config.yaml"
+echo ""
+
+# Offer to restart service
+if systemctl is-active --quiet pymc-repeater 2>/dev/null; then
+    read -p "Restart pymc-repeater service now? (yes/no): " RESTART
+    if [ "$RESTART" = "yes" ]; then
+        systemctl restart pymc-repeater
+        echo "✓ Service restarted"
+        echo ""
+        echo "Check logs for new identity:"
+        echo "  sudo journalctl -u pymc-repeater -f | grep -i 'identity\|hash'"
+    else
+        echo "Remember to restart the service:"
+        echo "  sudo systemctl restart pymc-repeater"
+    fi
+else
+    echo "Note: pymc-repeater service is not running"
+    echo "Start it with: sudo systemctl start pymc-repeater"
+fi