Version v0.3.35 - Convert to decimal units (1000-based) to match system tools, add posix_fallocate for guaranteed space allocation, use f_bavail for accurate space reporting, add drive info to Pad Management header

README.md

@@ -1,51 +1,8 @@
 # OTP Cipher - One Time Pad Implementation
 
-## Quick Start
-
-### Download Pre-Built Binaries
-
-**[📥 Download Latest Release](https://git.laantungir.net/laantungir/otp/releases)**
-
-Visit the releases page and download the appropriate binary for your system:
-- `otp-vX.X.X-linux-x86_64` for Intel/AMD 64-bit systems
-- `otp-vX.X.X-linux-arm64` for Raspberry Pi and ARM 64-bit systems
-
-After downloading:
-```bash
-# Make executable and run
-chmod +x otp-v*-linux-x86_64
-./otp-v*-linux-x86_64
-```
-
-**Or use the local build:**
-```bash
-# After building from source
-./build/otp-x86_64    # x86_64 systems
-./build/otp-arm64     # ARM64 systems
-```
-
-### First Steps
-
-1. **Generate your first pad:**
-   ```bash
-   ./build/otp-x86_64 generate 1GB
-   ```
-
-2. **Encrypt a message:**
-   ```bash
-   ./build/otp-x86_64 encrypt
-   # Follow the interactive prompts
-   ```
-
-3. **Decrypt a message:**
-   ```bash
-   ./build/otp-x86_64 decrypt
-   # Paste the encrypted message
-   ```
-
 ## 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
 
@@ -83,8 +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
@@ -99,73 +54,102 @@ 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/v0.3.34/otp-v0.3.34-linux-x86_64)**
+
+**[Download Current Raspberry Pi 64](https://git.laantungir.net/laantungir/otp/releases/download/v0.3.34/otp-v0.3.34-linux-arm64)**
+
+After downloading:
+```bash
+# Rename for convenience, then make executable
+mv otp-v0.3.34-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
-- Optional: ARM64 cross-compiler (`gcc-aarch64-linux-gnu`) for cross-compilation
 
 ### Build Commands
 
-Use the included build script for automatic versioning and cross-compilation:
-
-```bash
-# Build for current architecture (with auto-versioning)
-./build.sh "commit message"
-
-# Build commands
-./build.sh build "commit message"  # Build x86_64 and ARM64 (if cross-compiler available)
-./build.sh clean                   # Clean build artifacts
-./build.sh install                 # Install to system
-./build.sh uninstall               # Remove from system
-```
-
-The build script automatically:
-- Increments patch version (v0.3.24 → v0.3.25)
-- Creates git commit and tag
-- Builds for x86_64 and ARM64 (if cross-compiler available)
-- Outputs to `build/otp-x86_64` and `build/otp-arm64`
-- Uploads binaries to Gitea releases (if `~/.gitea_token` exists)
-
-### Traditional Make
-
-You can also use make directly (without automatic versioning):
-
 ```bash
 make            # Build for current architecture
-make static     # Static linking
-make clean      # Clean artifacts
+make static     # Static linking (standalone binary)
+make clean      # Clean build artifacts
 make install    # Install to /usr/local/bin/otp
 make uninstall  # Remove from system
 ```
 
 Output: `build/otp-$(ARCH)` (e.g., `build/otp-x86_64`)
 
-## Usage
-
-### Interactive Mode
+After building, run with:
 ```bash
 ./build/otp-x86_64
-# or
-./build/otp-arm64  # On ARM systems
 ```
 
+## 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
-./build/otp-x86_64 generate 1GB
+./otp generate 1GB
 
-# Encrypt text (interactive input)
-./build/otp-x86_64 encrypt <pad_hash_or_prefix>
+# Encrypt text (will prompt for input)
+./otp encrypt <pad_hash_or_prefix>
 
-# Decrypt message (interactive input)
-./build/otp-x86_64 decrypt <pad_hash_or_prefix>
+# Decrypt message (will prompt for input)
+./otp decrypt <pad_hash_or_prefix>
 
 # List available pads
-./build/otp-x86_64 list
+./otp list
 ```
 
 ## Version System

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/entropy.c

@@ -82,7 +82,7 @@ int add_entropy_direct_xor(const char* pad_chksum, const unsigned char* entropy_
 
     if (display_progress) {
         printf("Adding entropy to pad using direct XOR...\n");
-        printf("Pad size: %.2f GB (%lu bytes)\n", (double)pad_size / (1024.0*1024.0*1024.0), pad_size);
+        printf("Pad size: %.2f GB (%lu bytes)\n", (double)pad_size / (1000.0*1000.0*1000.0), pad_size);
         printf("Entropy size: %zu bytes\n", entropy_size);
     }
 
@@ -212,7 +212,7 @@ int add_entropy_chacha20(const char* pad_chksum, const unsigned char* entropy_da
 
     if (display_progress) {
         printf("Adding entropy to pad using Chacha20...\n");
-        printf("Pad size: %.2f GB (%lu bytes)\n", (double)pad_size / (1024.0*1024.0*1024.0), pad_size);
+        printf("Pad size: %.2f GB (%lu bytes)\n", (double)pad_size / (1000.0*1000.0*1000.0), pad_size);
     }
 
     // Process pad in chunks
@@ -593,8 +593,8 @@ int add_file_entropy_streaming(const char* pad_chksum, const char* file_path, si
 
     if (display_progress) {
         printf("Adding entropy to pad using streaming direct XOR...\n");
-        printf("Pad size: %.2f GB (%lu bytes)\n", (double)pad_size / (1024.0*1024.0*1024.0), pad_size);
-        printf("Entropy file: %.2f GB (%zu bytes)\n", (double)file_size / (1024.0*1024.0*1024.0), file_size);
+        printf("Pad size: %.2f GB (%lu bytes)\n", (double)pad_size / (1000.0*1000.0*1000.0), pad_size);
+        printf("Entropy file: %.2f GB (%zu bytes)\n", (double)file_size / (1000.0*1000.0*1000.0), file_size);
     }
 
     // Process in chunks

src/main.h

@@ -23,7 +23,7 @@
 #include <ctype.h>
 
 // Version - Updated automatically by build.sh
-#define OTP_VERSION "v0.3.30"
+#define OTP_VERSION "v0.3.34"
 
 // Constants
 #define MAX_INPUT_SIZE 4096

src/pads.c

@@ -43,9 +43,9 @@ int show_pad_info(const char* chksum) {
     printf("ChkSum: %s\n", chksum);
     printf("File: %s\n", pad_filename);
 
-    double size_gb = (double)st.st_size / (1024.0 * 1024.0 * 1024.0);
-    double used_gb = (double)used_bytes / (1024.0 * 1024.0 * 1024.0);
-    double remaining_gb = (double)(st.st_size - used_bytes) / (1024.0 * 1024.0 * 1024.0);
+    double size_gb = (double)st.st_size / (1000.0 * 1000.0 * 1000.0);
+    double used_gb = (double)used_bytes / (1000.0 * 1000.0 * 1000.0);
+    double remaining_gb = (double)(st.st_size - used_bytes) / (1000.0 * 1000.0 * 1000.0);
 
     printf("Total size: %.2f GB (%lu bytes)\n", size_gb, st.st_size);
     printf("Used: %.2f GB (%lu bytes)\n", used_gb, used_bytes);
@@ -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;
-        double available_gb = (double)available_bytes / (1024.0 * 1024.0 * 1024.0);
-        double required_gb = (double)size_bytes / (1024.0 * 1024.0 * 1024.0);
+        // 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 / (1000.0 * 1000.0 * 1000.0);
+        double required_gb = (double)size_bytes / (1000.0 * 1000.0 * 1000.0);
         
         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 / (1000.0 * 1000.0 * 1000.0);
+    
+    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 / (1000.0 * 1000.0 * 1000.0);
+        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");
@@ -384,25 +434,25 @@ char* select_pad_interactive(const char* title, const char* prompt, pad_filter_t
                 }
 
                 // Format total size
-                if (st.st_size < 1024) {
+                if (st.st_size < 1000) {
                     snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%luB", st.st_size);
-                } else if (st.st_size < 1024 * 1024) {
-                    snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%.1fKB", (double)st.st_size / 1024.0);
-                } else if (st.st_size < 1024 * 1024 * 1024) {
-                    snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%.1fMB", (double)st.st_size / (1024.0 * 1024.0));
+                } else if (st.st_size < 1000 * 1000) {
+                    snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%.1fKB", (double)st.st_size / 1000.0);
+                } else if (st.st_size < 1000 * 1000 * 1000) {
+                    snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%.1fMB", (double)st.st_size / (1000.0 * 1000.0));
                 } else {
-                    snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%.2fGB", (double)st.st_size / (1024.0 * 1024.0 * 1024.0));
+                    snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%.2fGB", (double)st.st_size / (1000.0 * 1000.0 * 1000.0));
                 }
 
                 // Format used size
-                if (used_bytes < 1024) {
+                if (used_bytes < 1000) {
                     snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%luB", used_bytes);
-                } else if (used_bytes < 1024 * 1024) {
-                    snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%.1fKB", (double)used_bytes / 1024.0);
-                } else if (used_bytes < 1024 * 1024 * 1024) {
-                    snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%.1fMB", (double)used_bytes / (1024.0 * 1024.0));
+                } else if (used_bytes < 1000 * 1000) {
+                    snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%.1fKB", (double)used_bytes / 1000.0);
+                } else if (used_bytes < 1000 * 1000 * 1000) {
+                    snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%.1fMB", (double)used_bytes / (1000.0 * 1000.0));
                 } else {
-                    snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%.2fGB", (double)used_bytes / (1024.0 * 1024.0 * 1024.0));
+                    snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%.2fGB", (double)used_bytes / (1000.0 * 1000.0 * 1000.0));
                 }
 
                 // Calculate percentage
@@ -584,6 +634,27 @@ int handle_pads_menu(void) {
 
     // Get list of pads from current directory
     const char* pads_dir = get_current_pads_dir();
+    
+    // Display directory and space information
+    printf("Pads Directory: %s\n", pads_dir);
+    
+    // Get filesystem space information
+    struct statvfs vfs_stat;
+    if (statvfs(pads_dir, &vfs_stat) == 0) {
+        uint64_t total_bytes = vfs_stat.f_blocks * vfs_stat.f_frsize;
+        uint64_t available_bytes = vfs_stat.f_bavail * vfs_stat.f_frsize;
+        uint64_t used_bytes = total_bytes - (vfs_stat.f_bfree * vfs_stat.f_frsize);
+        
+        double total_gb = (double)total_bytes / (1000.0 * 1000.0 * 1000.0);
+        double available_gb = (double)available_bytes / (1000.0 * 1000.0 * 1000.0);
+        double used_gb = (double)used_bytes / (1000.0 * 1000.0 * 1000.0);
+        double used_percent = (double)used_bytes / total_bytes * 100.0;
+        
+        printf("Drive Space: %.2f GB total, %.2f GB used (%.1f%%), %.2f GB available\n",
+               total_gb, used_gb, used_percent, available_gb);
+    }
+    printf("\n");
+    
     DIR* dir = opendir(pads_dir);
     if (!dir) {
         printf("Error: Cannot open pads directory %s\n", pads_dir);
@@ -619,25 +690,25 @@ int handle_pads_menu(void) {
                 read_state_offset(pads[pad_count].chksum, &used_bytes);
 
                 // Format total size
-                if (st.st_size < 1024) {
+                if (st.st_size < 1000) {
                     snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%luB", st.st_size);
-                } else if (st.st_size < 1024 * 1024) {
-                    snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%.1fKB", (double)st.st_size / 1024.0);
-                } else if (st.st_size < 1024 * 1024 * 1024) {
-                    snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%.1fMB", (double)st.st_size / (1024.0 * 1024.0));
+                } else if (st.st_size < 1000 * 1000) {
+                    snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%.1fKB", (double)st.st_size / 1000.0);
+                } else if (st.st_size < 1000 * 1000 * 1000) {
+                    snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%.1fMB", (double)st.st_size / (1000.0 * 1000.0));
                 } else {
-                    snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%.2fGB", (double)st.st_size / (1024.0 * 1024.0 * 1024.0));
+                    snprintf(pads[pad_count].size_str, sizeof(pads[pad_count].size_str), "%.2fGB", (double)st.st_size / (1000.0 * 1000.0 * 1000.0));
                 }
 
                 // Format used size
-                if (used_bytes < 1024) {
+                if (used_bytes < 1000) {
                     snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%luB", used_bytes);
-                } else if (used_bytes < 1024 * 1024) {
-                    snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%.1fKB", (double)used_bytes / 1024.0);
-                } else if (used_bytes < 1024 * 1024 * 1024) {
-                    snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%.1fMB", (double)used_bytes / (1024.0 * 1024.0));
+                } else if (used_bytes < 1000 * 1000) {
+                    snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%.1fKB", (double)used_bytes / 1000.0);
+                } else if (used_bytes < 1000 * 1000 * 1000) {
+                    snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%.1fMB", (double)used_bytes / (1000.0 * 1000.0));
                 } else {
-                    snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%.2fGB", (double)used_bytes / (1024.0 * 1024.0 * 1024.0));
+                    snprintf(pads[pad_count].used_str, sizeof(pads[pad_count].used_str), "%.2fGB", (double)used_bytes / (1000.0 * 1000.0 * 1000.0));
                 }
 
                 // Calculate percentage
@@ -949,9 +1020,9 @@ int handle_verify_pad(const char* chksum) {
     printf("ChkSum: %s\n", chksum);
     printf("File: %s\n", pad_filename);
 
-    double size_gb = (double)st.st_size / (1024.0 * 1024.0 * 1024.0);
-    double used_gb = (double)used_bytes / (1024.0 * 1024.0 * 1024.0);
-    double remaining_gb = (double)(st.st_size - used_bytes) / (1024.0 * 1024.0 * 1024.0);
+    double size_gb = (double)st.st_size / (1000.0 * 1000.0 * 1000.0);
+    double used_gb = (double)used_bytes / (1000.0 * 1000.0 * 1000.0);
+    double remaining_gb = (double)(st.st_size - used_bytes) / (1000.0 * 1000.0 * 1000.0);
 
     printf("Total size: %.2f GB (%lu bytes)\n", size_gb, st.st_size);
     printf("Used: %.2f GB (%lu bytes)\n", used_gb, used_bytes);
@@ -1017,7 +1088,7 @@ int handle_delete_pad(const char* chksum) {
         uint64_t used_bytes;
         read_state_offset(chksum, &used_bytes);
 
-        double size_gb = (double)st.st_size / (1024.0 * 1024.0 * 1024.0);
+        double size_gb = (double)st.st_size / (1000.0 * 1000.0 * 1000.0);
         printf("\nPad to delete:\n");
         printf("Checksum: %s\n", chksum);
         printf("Size: %.2f GB\n", size_gb);
@@ -1205,7 +1276,7 @@ int handle_add_entropy_to_pad(const char* pad_chksum) {
         target_bytes = (size_t)pad_stat.st_size;
         printf("\nHardware RNG selected - will enhance entire pad with hardware entropy\n");
         printf("Pad size: %.2f GB (%zu bytes)\n",
-                (double)target_bytes / (1024.0 * 1024.0 * 1024.0), target_bytes);
+                (double)target_bytes / (1000.0 * 1000.0 * 1000.0), target_bytes);
     } else if (entropy_source == ENTROPY_SOURCE_FILE) {
         // Special handling for file entropy - ask for file path first
         char file_path[512];
@@ -1227,7 +1298,7 @@ int handle_add_entropy_to_pad(const char* pad_chksum) {
         printf("\nFile vs Pad Size Analysis:\n");
         printf("  Entropy file: %zu bytes\n", file_size);
         printf("  Target pad: %.2f GB (%lu bytes)\n",
-               (double)pad_size / (1024.0 * 1024.0 * 1024.0), pad_size);
+               (double)pad_size / (1000.0 * 1000.0 * 1000.0), pad_size);
 
         // Smart method selection based on file size vs pad size
         if (file_size >= pad_size) {
@@ -1411,10 +1482,10 @@ int handle_add_entropy_to_pad(const char* pad_chksum) {
 
         printf("✓ Device test successful!\n");
         printf("  Test collected: %zu bytes in %.1f seconds\n", test_collected, test_time);
-        printf("  Speed: %.1f KB/s (%.1f MB/s)\n", bytes_per_second / 1024.0, bytes_per_second / (1024.0 * 1024.0));
+        printf("  Speed: %.1f KB/s (%.1f MB/s)\n", bytes_per_second / 1000.0, bytes_per_second / (1000.0 * 1000.0));
 
         printf("\nPad enhancement estimate:\n");
-        printf("  Pad size: %.2f GB (%zu bytes)\n", (double)target_bytes / (1024.0 * 1024.0 * 1024.0), target_bytes);
+        printf("  Pad size: %.2f GB (%zu bytes)\n", (double)target_bytes / (1000.0 * 1000.0 * 1000.0), target_bytes);
 
         if (estimated_hours >= 1.0) {
             printf("  Estimated time: %.1f hours\n", estimated_hours);

src/trng.c

@@ -153,7 +153,7 @@ int collect_truerng_entropy_streaming_from_device(const hardware_rng_device_t* d
 
     if (display_progress) {
         printf("Streaming entropy from %s to pad...\n", device->friendly_name);
-        printf("Pad size: %.2f GB (%lu bytes)\n", (double)pad_size / (1024.0*1024.0*1024.0), pad_size);
+        printf("Pad size: %.2f GB (%lu bytes)\n", (double)pad_size / (1000.0*1000.0*1000.0), pad_size);
         printf("Enhancing entire pad with hardware entropy\n");
     }
 

src/ui.c

@@ -152,7 +152,7 @@ int handle_generate_menu(void) {
         return 1;
     }
 
-    double size_gb = (double)size / (1024.0 * 1024.0 * 1024.0);
+    double size_gb = (double)size / (1000.0 * 1000.0 * 1000.0);
     printf("Generating %.2f GB pad...\n", size_gb);
     printf("Note: Use 'Add entropy' in Pads menu to enhance randomness after creation.\n");
 

src/util.c

@@ -519,13 +519,13 @@ uint64_t parse_size_string(const char* size_str) {
         }
 
         if (strcmp(unit, "K") == 0 || strcmp(unit, "KB") == 0) {
-            multiplier = 1024ULL;
+            multiplier = 1000ULL;
         } else if (strcmp(unit, "M") == 0 || strcmp(unit, "MB") == 0) {
-            multiplier = 1024ULL * 1024ULL;
+            multiplier = 1000ULL * 1000ULL;
         } else if (strcmp(unit, "G") == 0 || strcmp(unit, "GB") == 0) {
-            multiplier = 1024ULL * 1024ULL * 1024ULL;
+            multiplier = 1000ULL * 1000ULL * 1000ULL;
         } else if (strcmp(unit, "T") == 0 || strcmp(unit, "TB") == 0) {
-            multiplier = 1024ULL * 1024ULL * 1024ULL * 1024ULL;
+            multiplier = 1000ULL * 1000ULL * 1000ULL * 1000ULL;
         } else {
             return 0; // Invalid unit
         }