readme and bashscript moving

scripts-bash/comic-scripts/cbt.sh

@@ -0,0 +1,204 @@
+#!/bin/bash
+
+# CBT (Comic Book Tar) Creator and Extractor
+# Creates and extracts .cbt files with optional AES encryption
+# Compatible with Go server encryption format
+
+set -e
+
+show_usage() {
+    echo "Usage:"
+    echo "  Create:  $0 create -i <input_directory> -o <output_file> [-p <password>]"
+    echo "  Extract: $0 extract -i <input_file> -o <output_directory> [-p <password>]"
+    echo ""
+    echo "Options:"
+    echo "  -i    Input directory/file"
+    echo "  -o    Output file/directory"
+    echo "  -p    Password for encryption/decryption (optional)"
+    echo ""
+    echo "Examples:"
+    echo "  $0 create -i ./comics -o mycomic.cbt"
+    echo "  $0 create -i ./comics -o mycomic.cbt -p mysecretpass"
+    echo "  $0 extract -i mycomic.cbt -o ./extracted"
+    echo "  $0 extract -i mycomic.cbt -o ./extracted -p mysecretpass"
+    echo ""
+    exit 1
+}
+
+# Parse command line arguments
+MODE="$1"
+shift || show_usage
+
+INPUT=""
+OUTPUT=""
+PASSWORD=""
+
+while getopts "i:o:p:h" opt; do
+    case $opt in
+        i) INPUT="$OPTARG" ;;
+        o) OUTPUT="$OPTARG" ;;
+        p) PASSWORD="$OPTARG" ;;
+        h) show_usage ;;
+        *) show_usage ;;
+    esac
+done
+
+# Validate mode
+if [ "$MODE" != "create" ] && [ "$MODE" != "extract" ]; then
+    echo "Error: First argument must be 'create' or 'extract'"
+    show_usage
+fi
+
+# Validate required arguments
+if [ -z "$INPUT" ] || [ -z "$OUTPUT" ]; then
+    echo "Error: Input and output are required"
+    show_usage
+fi
+
+# Encrypt data using AES-CFB
+encrypt_data() {
+    local input_file="$1"
+    local output_file="$2"
+    local password="$3"
+
+    # Derive key using SHA256 (same as Go)
+    local key=$(echo -n "$password" | sha256sum | cut -d' ' -f1 | xxd -r -p | base64)
+
+    # Generate random IV (16 bytes for AES)
+    local iv=$(openssl rand -base64 16)
+
+    # Encrypt using AES-256-CFB
+    # First write IV, then encrypted data
+    echo -n "$iv" | base64 -d > "$output_file"
+    openssl enc -aes-256-cfb -K "$(echo -n "$password" | sha256sum | cut -d' ' -f1)" -iv "$(echo -n "$iv" | base64 -d | xxd -p -c 256)" -in "$input_file" >> "$output_file"
+}
+
+# Decrypt data using AES-CFB (compatible with Go implementation)
+decrypt_data() {
+    local input_file="$1"
+    local output_file="$2"
+    local password="$3"
+
+    # Extract IV (first 16 bytes)
+    local iv_hex=$(head -c 16 "$input_file" | xxd -p -c 256)
+
+    # Extract ciphertext (rest of file)
+    tail -c +17 "$input_file" > "${output_file}.tmp"
+
+    # Decrypt using AES-256-CFB
+    if ! openssl enc -d -aes-256-cfb -K "$(echo -n "$password" | sha256sum | cut -d' ' -f1)" -iv "$iv_hex" -in "${output_file}.tmp" -out "$output_file" 2>/dev/null; then
+        rm -f "${output_file}.tmp"
+        return 1
+    fi
+
+    rm -f "${output_file}.tmp"
+    return 0
+}
+
+# CREATE MODE
+create_cbt() {
+    INPUT_DIR="$INPUT"
+    OUTPUT_FILE="$OUTPUT"
+
+    # Check if input directory exists
+    if [ ! -d "$INPUT_DIR" ]; then
+        echo "Error: Input directory '$INPUT_DIR' does not exist"
+        exit 1
+    fi
+
+    # Ensure output has .cbt extension
+    if [[ ! "$OUTPUT_FILE" =~ \.cbt$ ]]; then
+        OUTPUT_FILE="${OUTPUT_FILE}.cbt"
+    fi
+
+    # Create unencrypted tar archive
+    echo "Creating tar archive from $INPUT_DIR..."
+    TMP_TAR=$(mktemp)
+
+    # Create tar file, preserving relative paths
+    tar -cf "$TMP_TAR" -C "$INPUT_DIR" .
+
+    # List files that were added
+    echo ""
+    echo "Files added:"
+    tar -tf "$TMP_TAR"
+    echo ""
+
+    if [ -n "$PASSWORD" ]; then
+        # Encrypted mode
+        echo "Encrypting with AES-CFB (Go-compatible format)..."
+
+        encrypt_data "$TMP_TAR" "$OUTPUT_FILE" "$PASSWORD"
+
+        rm "$TMP_TAR"
+        echo "Created encrypted CBT: $OUTPUT_FILE"
+    else
+        # Unencrypted mode - just move the tar file
+        mv "$TMP_TAR" "$OUTPUT_FILE"
+        echo "Created unencrypted CBT: $OUTPUT_FILE"
+    fi
+
+    echo "Done!"
+}
+
+# EXTRACT MODE
+extract_cbt() {
+    INPUT_FILE="$INPUT"
+    OUTPUT_DIR="$OUTPUT"
+
+    # Check if input file exists
+    if [ ! -f "$INPUT_FILE" ]; then
+        echo "Error: Input file '$INPUT_FILE' does not exist"
+        exit 1
+    fi
+
+    # Create output directory if it doesn't exist
+    mkdir -p "$OUTPUT_DIR"
+
+    TMP_TAR=$(mktemp)
+
+    # Check if file is encrypted by trying to read as tar first
+    if tar -tf "$INPUT_FILE" >/dev/null 2>&1; then
+        # File is unencrypted tar
+        cp "$INPUT_FILE" "$TMP_TAR"
+    else
+        # File appears to be encrypted
+        if [ -z "$PASSWORD" ]; then
+            echo "Error: File appears to be encrypted. Please provide password with -p flag."
+            rm "$TMP_TAR"
+            exit 1
+        fi
+
+        echo "Decrypting $INPUT_FILE..."
+
+        if ! decrypt_data "$INPUT_FILE" "$TMP_TAR" "$PASSWORD"; then
+            echo "Error: Failed to decrypt. Wrong password or corrupted file."
+            exit 1
+        fi
+
+        echo "Decryption successful!"
+    fi
+
+    # Extract tar archive
+    echo "Extracting to $OUTPUT_DIR..."
+
+    if tar -xf "$TMP_TAR" -C "$OUTPUT_DIR" 2>/dev/null; then
+        echo ""
+        echo "Files extracted:"
+        tar -tf "$TMP_TAR"
+        echo ""
+        echo "Extraction complete!"
+    else
+        rm "$TMP_TAR"
+        echo "Error: Failed to extract. File may be corrupted."
+        exit 1
+    fi
+
+    rm "$TMP_TAR"
+}
+
+if [ "$MODE" = "create" ]; then
+    create_cbt
+elif [ "$MODE" = "extract" ]; then
+    extract_cbt
+fi