Version v0.3.34 - Fixed usb space reporting

Makefile

@@ -11,11 +11,13 @@ OBJS = $(SOURCES:.c=.o)
 $(TARGET): $(OBJS)
 	@mkdir -p build
 	$(CC) $(CFLAGS) -o $(TARGET) $(OBJS) $(LIBS)
+	@rm -f $(OBJS)
 
 # Static linking target
 static: $(OBJS)
 	@mkdir -p build
 	$(CC) $(CFLAGS) -o $(TARGET) $(OBJS) $(LIBS_STATIC)
+	@rm -f $(OBJS)
 
 %.o: %.c
 	$(CC) $(CFLAGS) -c $< -o $@

README.md

@@ -1,9 +1,8 @@
 # OTP Cipher - One Time Pad Implementation
 
-
 ## Introduction
 
-A secure one-time pad (OTP) cipher implementation in C.
+A secure one-time pad (OTP) cipher implementation in C99.
 
 ## Why One-Time Pads
 
@@ -41,8 +40,6 @@ To address this problem, we can use Nostr to share among devices the place in th
 One-time pads can be trivially encrypted and decrypted using pencil and paper, making them accessible even without electronic devices.
 
 
-
-
 ## Features
 
 - **Perfect Security**: Implements true one-time pad encryption with information-theoretic security
@@ -57,106 +54,134 @@ One-time pads can be trivially encrypted and decrypted using pencil and paper, m
 - **Cross-Platform**: Works on Linux and other UNIX-like systems
 
 
-## Building
+## Quick Start
+
+### Download Pre-Built Binaries
+
+**[Download Current Linux x86](https://git.laantungir.net/laantungir/otp/releases/download/v0.3.33/otp-v0.3.33-linux-x86_64)**
+
+**[Download Current Raspberry Pi 64](https://git.laantungir.net/laantungir/otp/releases/download/v0.3.33/otp-v0.3.33-linux-arm64)**
+
+After downloading:
+```bash
+# Rename for convenience, then make executable
+mv otp-v0.3.33-linux-x86_64 otp
+chmod +x otp
+
+# Run it
+./otp
+```
+### First Steps
+
+1. **Generate your first pad:**
+   ```bash
+   ./otp generate 1GB
+   ```
+
+2. **Encrypt a message:**
+   ```bash
+   ./otp encrypt
+   # Follow the interactive prompts
+   ```
+
+3. **Decrypt a message:**
+   ```bash
+   ./otp decrypt
+   # Paste the encrypted message
+   ```
+
+
+
+## Building from Source
 
 ### Prerequisites
 
 - GCC compiler
-- Git (for version tracking)
 - Make
 
-
-
 ### Build Commands
 
-Use the included build script for automatic versioning:
-
 ```bash
-# Standard build (default)
-./build.sh build
-
-# Static linking build
-./build.sh static
-
-# Clean build artifacts
-./build.sh clean
-
-# Generate version files only
-./build.sh version
-
-# Install to system
-./build.sh install
-
-# Remove from system
-./build.sh uninstall
-
-# Show usage
-./build.sh help
+make            # Build for current architecture
+make static     # Static linking (standalone binary)
+make clean      # Clean build artifacts
+make install    # Install to /usr/local/bin/otp
+make uninstall  # Remove from system
 ```
 
-### Traditional Make
-
-You can also use make directly (without automatic versioning):
+Output: `build/otp-$(ARCH)` (e.g., `build/otp-x86_64`)
 
+After building, run with:
 ```bash
-make            # Standard build
-make static     # Static linking
-make clean      # Clean artifacts
-make install    # Install to /usr/local/bin/
-make uninstall  # Remove from system
+./build/otp-x86_64
 ```
 
 ## Usage
 
+The OTP Cipher operates in two modes:
+
+**Interactive Mode**: Run without arguments to access a menu-driven interface. Best for exploring features, managing pads, and performing operations step-by-step with prompts and guidance.
+
+**Command Line Mode**: Provide arguments to execute specific operations directly. Ideal for scripting, automation, and quick one-off tasks.
+
 ### Interactive Mode
+
+Launch the menu-driven interface:
+
 ```bash
 ./otp
 ```
 
+Navigate through menus to generate pads, encrypt/decrypt messages, manage pads, and configure settings.
+
 ### Command Line Mode
+
+Execute operations directly with arguments:
+
 ```bash
 # Generate a new pad
 ./otp generate 1GB
 
-# Encrypt text (interactive input)
+# Encrypt text (will prompt for input)
 ./otp encrypt <pad_hash_or_prefix>
 
-# Decrypt message (interactive input)  
+# Decrypt message (will prompt for input)
 ./otp decrypt <pad_hash_or_prefix>
 
 # List available pads
 ./otp list
 ```
 
-## Version System Details
+## Version System
+
+### Centralized Version Management
+Version is defined in a single location: `src/main.h`
+```c
+#define OTP_VERSION "v0.3.24"
+```
+
+All code references this constant, ensuring consistency across:
+- Main menu display
+- ASCII armor output
+- Help/usage text
 
 ### Automatic Version Increment
-Every build automatically increments the patch version:
-- v0.1.0 → v0.1.1 → v0.1.2, etc.
-- Creates git tags for each version
-- Embeds detailed build information
+The `build.sh` script automatically:
+1. Increments patch version (v0.3.24 → v0.3.25)
+2. Updates `OTP_VERSION` in `src/main.h`
+3. Creates git commit and tag
+4. Pushes to remote repository
 
 ### Manual Version Control
 For major/minor releases, create tags manually:
 ```bash
 # Feature release (minor bump)
-git tag v0.2.0    # Next build: v0.2.1
+git tag v0.4.0    # Next build: v0.4.1
 
 # Breaking change (major bump)
 git tag v1.0.0    # Next build: v1.0.1
 ```
 
-### Version Information Available
-- Version number (major.minor.patch)
-- Git commit hash and branch
-- Build date and time
-- Full version display with metadata
-
-### Generated Files
-The build system automatically manages Git versioning by incrementing tags.
-
-These files are excluded from git (.gitignore) and regenerated on each build.
-
 ## Security Features
 
 - Uses `/dev/urandom` for cryptographically secure random number generation
@@ -166,28 +191,32 @@ These files are excluded from git (.gitignore) and regenerated on each build.
 - State tracking to prevent pad reuse
 - **Zero external crypto dependencies** - completely self-contained implementation
 
-## File Structure
+## Project Structure
 
 ```
 otp/
 ├── build.sh              # Build script with automatic versioning
 ├── Makefile             # Traditional make build system
-├── otp.c            # Legacy compatibility and global definitions
 ├── README.md            # This file
 ├── .gitignore           # Git ignore rules
-├── include/
-│   └── otp.h        # Public API header with all function prototypes
 ├── src/
-│   ├── main.c       # Main application entry point and command line handling
+│   ├── main.h           # Main header with all prototypes and OTP_VERSION
+│   ├── main.c           # Application entry point and command line handling
 │   ├── ui.c             # Interactive user interface and menu system
-│   ├── state.c      # Global state management (pads directory, terminal dimensions)
-│   ├── crypto.c     # Core cryptographic operations (XOR, ChaCha20)
+│   ├── state.c          # Global state management (pads directory, preferences)
+│   ├── crypto.c         # Core cryptographic operations (XOR, base64)
 │   ├── pads.c           # Pad management and file operations
 │   ├── entropy.c        # Entropy collection from various sources
-│   ├── trng.c       # Hardware RNG device detection and entropy collection
-│   └── util.c       # Utility functions and helpers
+│   ├── trng.c           # Hardware RNG device detection and collection
+│   ├── util.c           # Utility functions and helpers
+│   ├── nostr_chacha20.c # ChaCha20 implementation for entropy expansion
+│   └── nostr_chacha20.h # ChaCha20 header
+├── build/
+│   ├── otp-x86_64       # Native x86_64 binary (created by build)
+│   └── otp-arm64        # ARM64 binary (created by cross-compilation)
 ├── pads/                # OTP pad storage directory (created at runtime)
-└── VERSION          # Plain text version (generated)
+├── files/               # Encrypted file storage (created at runtime)
+└── tests/               # Test scripts and utilities
 ```
 
 ## Architecture
@@ -197,13 +226,14 @@ The OTP cipher uses a modular architecture with clean separation of concerns:
 - **main.c**: Application entry point, command line parsing, and mode selection
 - **ui.c**: Interactive user interface, menus, and terminal management
 - **state.c**: Global state management (pads directory, terminal dimensions, preferences)
-- **crypto.c**: Core cryptographic operations (XOR encryption, ChaCha20 entropy mixing)
+- **crypto.c**: Core cryptographic operations (XOR encryption, base64 encoding)
 - **pads.c**: Pad file management, checksums, and state tracking
-- **entropy.c**: Entropy collection from keyboard, dice, and other sources
+- **entropy.c**: Entropy collection from keyboard, dice, files, and hardware RNG
 - **trng.c**: Hardware RNG device detection and entropy collection from USB devices
 - **util.c**: Utility functions, file operations, and helper routines
+- **nostr_chacha20.c**: ChaCha20 stream cipher for entropy expansion
 
-All modules share a common header (`include/otp.h`) that defines the public API and data structures.
+All modules share a common header (`src/main.h`) that defines the public API, data structures, and version constant.
 
 ## Hardware RNG Device Support
 
@@ -405,9 +435,22 @@ No.  ChkSum (first 16 chars) Size         Used         % Used
 
 This project includes automatic versioning system based on the Generic Automatic Version Increment System.
 
+## State Files
+
+Pad state files (`.state`) use a human-readable text format:
+```
+offset=1234567890
+```
+
+This tracks how many bytes of each pad have been used. The format is:
+- **Human-readable**: Can inspect with `cat checksum.state`
+- **Backward compatible**: Automatically reads old binary format
+- **Easy to debug**: Can manually edit if needed
+
 ## Contributing
 
 When contributing:
-1. The version will automatically increment on builds
-2. For major features, consider manually creating minor version tags
-3. Generated version files (`src/version.*`, `VERSION`) should not be committed
+1. The version will automatically increment on builds via `build.sh`
+2. Version is centralized in `src/main.h` as `OTP_VERSION`
+3. For major features, manually create minor/major version tags
+4. Build artifacts in `build/` and object files are auto-cleaned

build.sh

@@ -155,6 +155,45 @@ update_source_version() {
     else
         print_warning "src/main.h not found - skipping version update"
     fi
+    
+    # Update README.md with direct download links
+    if [ -f "README.md" ]; then
+        print_status "Updating README.md with download links for $NEW_VERSION..."
+        
+        # Create the new download section with direct download links
+        local NEW_DOWNLOAD_SECTION="### Download Pre-Built Binaries
+
+**[Download Current Linux x86](https://git.laantungir.net/laantungir/otp/releases/download/${NEW_VERSION}/otp-${NEW_VERSION}-linux-x86_64)**
+
+**[Download Current Raspberry Pi 64](https://git.laantungir.net/laantungir/otp/releases/download/${NEW_VERSION}/otp-${NEW_VERSION}-linux-arm64)**
+
+After downloading:
+\`\`\`bash
+# Rename for convenience, then make executable
+mv otp-${NEW_VERSION}-linux-x86_64 otp
+chmod +x otp
+
+# Run it
+./otp
+\`\`\`"
+        
+        # Use awk to replace the section between "### Download Pre-Built Binaries" and "### First Steps"
+        awk -v new_section="$NEW_DOWNLOAD_SECTION" '
+            /^### Download Pre-Built Binaries/ {
+                print new_section
+                skip=1
+                next
+            }
+            /^### First Steps/ {
+                skip=0
+            }
+            !skip
+        ' README.md > README.md.tmp && mv README.md.tmp README.md
+        
+        print_success "Updated README.md with download links for $NEW_VERSION"
+    else
+        print_warning "README.md not found - skipping README update"
+    fi
 }
 
 # Cross-platform build functions

src/main.h

@@ -23,7 +23,7 @@
 #include <ctype.h>
 
 // Version - Updated automatically by build.sh
-#define OTP_VERSION "v0.3.24"
+#define OTP_VERSION "v0.3.33"
 
 // Constants
 #define MAX_INPUT_SIZE 4096

src/pads.c

@@ -89,18 +89,18 @@ int generate_pad(uint64_t size_bytes, int display_progress) {
     const char* pads_dir = get_current_pads_dir();
     struct statvfs stat;
     if (statvfs(pads_dir, &stat) == 0) {
-        // Use f_bfree (total free blocks) instead of f_bavail (available to non-root)
-        // This gives the actual free space on the filesystem, which is more accurate
-        // for removable media and user-owned directories
-        uint64_t available_bytes = stat.f_bfree * stat.f_frsize;
+        // Use f_bavail (available to non-root users) for accurate space reporting
+        // This accounts for filesystem reserved space (e.g., 5% on ext4)
+        uint64_t available_bytes = stat.f_bavail * stat.f_frsize;
         double available_gb = (double)available_bytes / (1024.0 * 1024.0 * 1024.0);
         double required_gb = (double)size_bytes / (1024.0 * 1024.0 * 1024.0);
         
         if (available_bytes < size_bytes) {
             printf("\n⚠ WARNING: Insufficient disk space!\n");
-            printf("  Required: %.2f GB\n", required_gb);
-            printf("  Available: %.2f GB\n", available_gb);
+            printf("  Required: %.2f GB (%lu bytes)\n", required_gb, size_bytes);
+            printf("  Available: %.2f GB (%lu bytes)\n", available_gb, available_bytes);
             printf("  Shortfall: %.2f GB\n", required_gb - available_gb);
+            printf("  Location: %s\n", pads_dir);
             printf("\nContinue anyway? (y/N): ");
             
             char response[10];
@@ -129,11 +129,54 @@ int generate_pad(uint64_t size_bytes, int display_progress) {
 
     FILE* pad_file = fopen(temp_filename, "wb");
     if (!pad_file) {
-        printf("Error: Cannot create temporary pad file %s\n", temp_filename);
+        printf("Error: Cannot create temporary pad file '%s': %s (errno %d)\n",
+               temp_filename, strerror(errno), errno);
         fclose(urandom);
         return 1;
     }
 
+    // Preallocate full file size using posix_fallocate for guaranteed space reservation
+    // This actually allocates disk blocks (unlike ftruncate which creates sparse files)
+    int fd = fileno(pad_file);
+    double size_gb = (double)size_bytes / (1024.0 * 1024.0 * 1024.0);
+    
+    if (display_progress) {
+        printf("Allocating %.2f GB on disk...\n", size_gb);
+    }
+    
+    int alloc_result = posix_fallocate(fd, 0, (off_t)size_bytes);
+    if (alloc_result != 0) {
+        printf("Error: Failed to allocate %.2f GB temp file: %s (errno %d)\n",
+               size_gb, strerror(alloc_result), alloc_result);
+        printf("  Temp file: %s\n", temp_filename);
+        printf("  Location: %s\n", pads_dir);
+        
+        if (alloc_result == ENOSPC) {
+            printf("  Cause: No space left on device\n");
+            printf("  This means the actual available space is less than reported\n");
+        } else if (alloc_result == EOPNOTSUPP) {
+            printf("  Cause: Filesystem doesn't support posix_fallocate\n");
+            printf("  Falling back to ftruncate (sparse file)...\n");
+            if (ftruncate(fd, (off_t)size_bytes) != 0) {
+                printf("  Fallback failed: %s\n", strerror(errno));
+                fclose(pad_file);
+                fclose(urandom);
+                unlink(temp_filename);
+                return 1;
+            }
+        } else {
+            printf("  Possible causes: quota limits, filesystem restrictions\n");
+            fclose(pad_file);
+            fclose(urandom);
+            unlink(temp_filename);
+            return 1;
+        }
+    }
+
+    if (display_progress && alloc_result == 0) {
+        printf("✓ Allocated %.2f GB on disk (guaranteed space)\n", size_gb);
+    }
+
     unsigned char buffer[64 * 1024]; // 64KB buffer
     uint64_t bytes_written = 0;
     time_t start_time = time(NULL);
@@ -149,7 +192,8 @@ int generate_pad(uint64_t size_bytes, int display_progress) {
         }
 
         if (fread(buffer, 1, (size_t)chunk_size, urandom) != (size_t)chunk_size) {
-            printf("Error: Failed to read from /dev/urandom\n");
+            printf("Error: Failed to read %lu bytes from /dev/urandom at position %lu: %s (errno %d)\n",
+                   chunk_size, bytes_written, strerror(errno), errno);
             fclose(urandom);
             fclose(pad_file);
             unlink(temp_filename);
@@ -157,7 +201,11 @@ int generate_pad(uint64_t size_bytes, int display_progress) {
         }
 
         if (fwrite(buffer, 1, (size_t)chunk_size, pad_file) != (size_t)chunk_size) {
-            printf("Error: Failed to write to pad file\n");
+            printf("Error: fwrite failed for %lu bytes at position %lu/%lu (%.1f%%): %s (errno %d)\n",
+                   chunk_size, bytes_written, size_bytes,
+                   (double)bytes_written / size_bytes * 100.0, strerror(errno), errno);
+            printf("  Temp file: %s\n", temp_filename);
+            printf("  Disk space was checked - possible causes: fragmentation, I/O timeout, quota\n");
             fclose(urandom);
             fclose(pad_file);
             unlink(temp_filename);
@@ -216,8 +264,10 @@ int generate_pad(uint64_t size_bytes, int display_progress) {
         return 1;
     }
 
-    double size_gb = (double)size_bytes / (1024.0 * 1024.0 * 1024.0);
-    printf("Generated pad: %s (%.2f GB)\n", pad_path, size_gb);
+    if (display_progress) {
+        double final_size_gb = (double)size_bytes / (1024.0 * 1024.0 * 1024.0);
+        printf("Generated pad: %s (%.2f GB)\n", pad_path, final_size_gb);
+    }
     printf("Pad checksum: %s\n", chksum_hex);
     printf("State file: %s\n", state_path);
     printf("Pad file set to read-only\n");