Added exponential padding to increase security.
This commit is contained in:
25
README.md
25
README.md
@@ -43,6 +43,7 @@ One-time pads can be trivially encrypted and decrypted using pencil and paper, m
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## Features
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- **Perfect Security**: Implements true one-time pad encryption with information-theoretic security
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- **Traffic Analysis Resistance**: Exponential bucketing with ISO/IEC 9797-1 Method 2 (Padmé) padding hides message lengths
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- **Text & File Encryption**: Supports both inline text and file encryption
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- **Multiple Output Formats**: Binary (.otp) and ASCII armored (.otp.asc) file formats
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- **Hardware RNG Support**: Direct entropy collection from TrueRNG USB devices with automatic detection
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@@ -58,14 +59,14 @@ One-time pads can be trivially encrypted and decrypted using pencil and paper, m
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### Download Pre-Built Binaries
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**[Download Current Linux x86](https://git.laantungir.net/laantungir/otp/releases/download/v0.3.47/otp-v0.3.47-linux-x86_64)**
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**[Download Current Linux x86](https://git.laantungir.net/laantungir/otp/releases/download/v0.3.48/otp-v0.3.48-linux-x86_64)**
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**[Download Current Raspberry Pi 64](https://git.laantungir.net/laantungir/otp/releases/download/v0.3.47/otp-v0.3.47-linux-arm64)**
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**[Download Current Raspberry Pi 64](https://git.laantungir.net/laantungir/otp/releases/download/v0.3.48/otp-v0.3.48-linux-arm64)**
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After downloading:
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```bash
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# Rename for convenience, then make executable
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mv otp-v0.3.47-linux-x86_64 otp
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mv otp-v0.3.48-linux-x86_64 otp
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chmod +x otp
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# Run it
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@@ -189,8 +190,23 @@ git tag v1.0.0 # Next build: v1.0.1
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- Custom 256-bit XOR checksum for pad identification (encrypted with pad data)
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- Read-only pad files to prevent accidental modification
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- State tracking to prevent pad reuse
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- **Message Length Hiding**: Exponential bucketing (256B, 512B, 1KB, 2KB, 4KB...) prevents traffic analysis
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- **ISO/IEC 9797-1 Method 2 Padding**: Standard-compliant Padmé padding with 0x80 marker
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- **Zero external crypto dependencies** - completely self-contained implementation
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### Message Padding
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All encrypted messages and files are automatically padded using exponential bucketing to resist traffic analysis attacks:
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- **Minimum size**: 256 bytes
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- **Bucket sizes**: 256B → 512B → 1KB → 2KB → 4KB → 8KB → ...
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- **Padding method**: ISO/IEC 9797-1 Method 2 (Padmé padding)
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- Appends `0x80` byte after message
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- Fills remaining space with `0x00` bytes
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- Unambiguous padding removal during decryption
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**Example**: A 10-byte message is padded to 256 bytes, while a 300-byte message is padded to 512 bytes. This provides strong protection for small messages where length leakage matters most, with logarithmic overhead for larger messages.
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## Project Structure
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```
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@@ -205,6 +221,7 @@ otp/
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│ ├── ui.c # Interactive user interface and menu system
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│ ├── state.c # Global state management (pads directory, preferences)
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│ ├── crypto.c # Core cryptographic operations (XOR, base64)
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│ ├── padding.c # Message padding (exponential bucketing, Padmé padding)
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│ ├── pads.c # Pad management and file operations
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│ ├── entropy.c # Entropy collection from various sources
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│ ├── trng.c # Hardware RNG device detection and collection
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@@ -217,6 +234,7 @@ otp/
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├── pads/ # OTP pad storage directory (created at runtime)
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├── files/ # Encrypted file storage (created at runtime)
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└── tests/ # Test scripts and utilities
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└── test_padding.sh # Padding implementation tests
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```
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## Architecture
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@@ -227,6 +245,7 @@ The OTP cipher uses a modular architecture with clean separation of concerns:
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- **ui.c**: Interactive user interface, menus, and terminal management
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- **state.c**: Global state management (pads directory, terminal dimensions, preferences)
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- **crypto.c**: Core cryptographic operations (XOR encryption, base64 encoding)
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- **padding.c**: Message padding implementation (exponential bucketing, ISO/IEC 9797-1 Method 2)
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- **pads.c**: Pad file management, checksums, and state tracking
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- **entropy.c**: Entropy collection from keyboard, dice, files, and hardware RNG
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- **trng.c**: Hardware RNG device detection and entropy collection from USB devices
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@@ -476,7 +476,18 @@ int decrypt_and_extract_directory(const char* encrypted_file, const char* output
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unlink(temp_decrypted);
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} else {
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// Not compressed, assume it's already TAR
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rename(temp_decrypted, temp_tar);
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printf("File is not compressed, using as TAR directly...\n");
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if (rename(temp_decrypted, temp_tar) != 0) {
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printf("Error: Failed to rename decrypted file to TAR file\n");
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unlink(temp_decrypted);
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return 1;
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}
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}
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// Verify TAR file exists before extraction
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if (access(temp_tar, F_OK) != 0) {
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printf("Error: TAR file does not exist at '%s'\n", temp_tar);
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return 1;
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}
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printf("Extracting archive...\n");
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285
src/crypto.c
285
src/crypto.c
@@ -401,18 +401,40 @@ int encrypt_text(const char* pad_identifier, const char* input_text) {
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return 1;
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}
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// Check if we have enough pad space
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struct stat pad_stat;
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if (stat(pad_path, &pad_stat) != 0) {
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printf("Error: Cannot get pad file size\n");
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// Calculate chunk size for padding (exponential bucketing)
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size_t chunk_size = calculate_chunk_size(input_len);
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// Allocate buffer for padded message
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unsigned char* padded_buffer = malloc(chunk_size);
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if (!padded_buffer) {
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printf("Error: Memory allocation failed\n");
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free(pad_chksum);
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return 1;
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}
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// Copy message to buffer and apply padding
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memcpy(padded_buffer, text_buffer, input_len);
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if (apply_padme_padding(padded_buffer, input_len, chunk_size) != 0) {
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printf("Error: Failed to apply padding\n");
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free(padded_buffer);
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free(pad_chksum);
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return 1;
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}
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if (current_offset + input_len > (uint64_t)pad_stat.st_size) {
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// Check if we have enough pad space (now using chunk_size instead of input_len)
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struct stat pad_stat;
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if (stat(pad_path, &pad_stat) != 0) {
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printf("Error: Cannot get pad file size\n");
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free(padded_buffer);
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free(pad_chksum);
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return 1;
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}
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if (current_offset + chunk_size > (uint64_t)pad_stat.st_size) {
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printf("Error: Not enough pad space remaining\n");
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printf("Need: %lu bytes, Available: %lu bytes\n",
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input_len, (uint64_t)pad_stat.st_size - current_offset);
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chunk_size, (uint64_t)pad_stat.st_size - current_offset);
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free(padded_buffer);
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free(pad_chksum);
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return 1;
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}
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@@ -432,37 +454,40 @@ int encrypt_text(const char* pad_identifier, const char* input_text) {
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return 1;
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}
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unsigned char* pad_data = malloc(input_len);
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if (fread(pad_data, 1, input_len, pad_file) != input_len) {
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unsigned char* pad_data = malloc(chunk_size);
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if (fread(pad_data, 1, chunk_size, pad_file) != chunk_size) {
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printf("Error: Cannot read pad data\n");
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free(pad_data);
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fclose(pad_file);
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free(padded_buffer);
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free(pad_chksum);
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return 1;
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}
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fclose(pad_file);
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// Use universal XOR operation for encryption
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unsigned char* ciphertext = malloc(input_len);
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if (universal_xor_operation((const unsigned char*)text_buffer, input_len, pad_data, ciphertext) != 0) {
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// Use universal XOR operation for encryption (now with padded data)
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unsigned char* ciphertext = malloc(chunk_size);
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if (universal_xor_operation(padded_buffer, chunk_size, pad_data, ciphertext) != 0) {
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printf("Error: Encryption operation failed\n");
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free(pad_data);
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free(ciphertext);
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free(padded_buffer);
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free(pad_chksum);
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return 1;
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}
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// Update state offset
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if (write_state_offset(pad_chksum, current_offset + input_len) != 0) {
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// Update state offset (now using chunk_size)
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if (write_state_offset(pad_chksum, current_offset + chunk_size) != 0) {
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printf("Warning: Failed to update state file\n");
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}
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// Use universal ASCII armor generator
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// Use universal ASCII armor generator (now with chunk_size)
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char* ascii_output;
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if (generate_ascii_armor(pad_chksum, current_offset, ciphertext, input_len, &ascii_output) != 0) {
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if (generate_ascii_armor(pad_chksum, current_offset, ciphertext, chunk_size, &ascii_output) != 0) {
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printf("Error: Failed to generate ASCII armor\n");
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free(pad_data);
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free(ciphertext);
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free(padded_buffer);
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free(pad_chksum);
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return 1;
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}
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@@ -479,6 +504,7 @@ int encrypt_text(const char* pad_identifier, const char* input_text) {
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// Cleanup
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free(pad_data);
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free(ciphertext);
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free(padded_buffer);
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free(ascii_output);
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free(pad_chksum);
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@@ -632,6 +658,22 @@ int universal_decrypt(const char* input_data, const char* output_target, decrypt
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return 1;
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}
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// Remove padding to get actual message
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size_t actual_msg_len;
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if (remove_padme_padding(ciphertext, ciphertext_len, &actual_msg_len) != 0) {
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if (mode == DECRYPT_MODE_SILENT) {
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fprintf(stderr, "Error: Invalid padding - message may be corrupted\n");
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} else {
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printf("Error: Invalid padding - message may be corrupted\n");
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}
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free(ciphertext);
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free(pad_data);
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return 1;
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}
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// Update ciphertext_len to actual message length
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ciphertext_len = actual_msg_len;
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// Output based on mode
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if (mode == DECRYPT_MODE_FILE_TO_FILE) {
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// Write to output file
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@@ -740,6 +782,9 @@ int encrypt_file(const char* pad_identifier, const char* input_file, const char*
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return 1;
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}
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// Calculate chunk size for padding (exponential bucketing)
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size_t chunk_size = calculate_chunk_size(file_size);
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// Check if pad file exists
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if (access(pad_path, R_OK) != 0) {
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printf("Error: Pad file %s not found\n", pad_path);
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@@ -774,10 +819,10 @@ int encrypt_file(const char* pad_identifier, const char* input_file, const char*
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return 1;
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}
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if (current_offset + file_size > (uint64_t)pad_stat.st_size) {
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if (current_offset + chunk_size > (uint64_t)pad_stat.st_size) {
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printf("Error: Not enough pad space remaining\n");
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printf("Need: %lu bytes, Available: %lu bytes\n",
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file_size, (uint64_t)pad_stat.st_size - current_offset);
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printf("Need: %lu bytes (file: %lu + padding), Available: %lu bytes\n",
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chunk_size, file_size, (uint64_t)pad_stat.st_size - current_offset);
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free(pad_chksum);
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return 1;
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}
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@@ -822,66 +867,93 @@ int encrypt_file(const char* pad_identifier, const char* input_file, const char*
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return 1;
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}
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// Read and encrypt file
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unsigned char buffer[64 * 1024];
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unsigned char pad_buffer[64 * 1024];
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unsigned char* encrypted_data = malloc(file_size);
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uint64_t bytes_processed = 0;
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// Allocate buffer for padded file data
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unsigned char* file_data = malloc(file_size);
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if (!file_data) {
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printf("Error: Memory allocation failed\n");
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fclose(input_fp);
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fclose(pad_file);
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free(pad_chksum);
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return 1;
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}
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printf("Encrypting %s...\n", input_file);
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while (bytes_processed < file_size) {
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uint64_t chunk_size = sizeof(buffer);
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if (file_size - bytes_processed < chunk_size) {
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chunk_size = file_size - bytes_processed;
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}
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// Read file data
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if (fread(buffer, 1, chunk_size, input_fp) != chunk_size) {
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printf("Error: Cannot read input file data\n");
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free(encrypted_data);
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fclose(input_fp);
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fclose(pad_file);
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free(pad_chksum);
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return 1;
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}
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// Read pad data
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if (fread(pad_buffer, 1, chunk_size, pad_file) != chunk_size) {
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printf("Error: Cannot read pad data\n");
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free(encrypted_data);
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fclose(input_fp);
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fclose(pad_file);
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free(pad_chksum);
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return 1;
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}
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// Use universal XOR operation for encryption
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if (universal_xor_operation(buffer, chunk_size, pad_buffer, &encrypted_data[bytes_processed]) != 0) {
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printf("Error: Encryption operation failed\n");
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free(encrypted_data);
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fclose(input_fp);
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fclose(pad_file);
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free(pad_chksum);
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return 1;
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}
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bytes_processed += chunk_size;
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// Show progress for large files (> 10MB)
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if (file_size > 10 * 1024 * 1024 && bytes_processed % (1024 * 1024) == 0) {
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// show_progress(bytes_processed, file_size, start_time); // MOVED TO src/util.c
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}
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// Read entire file
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if (fread(file_data, 1, file_size, input_fp) != file_size) {
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printf("Error: Cannot read input file\n");
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free(file_data);
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fclose(input_fp);
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fclose(pad_file);
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free(pad_chksum);
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return 1;
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}
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if (file_size > 10 * 1024 * 1024) {
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// show_progress(file_size, file_size, start_time); // MOVED TO src/util.c
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printf("\n");
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}
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fclose(input_fp);
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// Allocate buffer for padded data
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unsigned char* padded_data = malloc(chunk_size);
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if (!padded_data) {
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printf("Error: Memory allocation failed\n");
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free(file_data);
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fclose(pad_file);
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free(pad_chksum);
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return 1;
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}
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// Copy file data and apply padding
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memcpy(padded_data, file_data, file_size);
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free(file_data);
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if (apply_padme_padding(padded_data, file_size, chunk_size) != 0) {
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printf("Error: Failed to apply padding\n");
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free(padded_data);
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fclose(pad_file);
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free(pad_chksum);
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return 1;
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}
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// Read pad data
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unsigned char* pad_data = malloc(chunk_size);
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if (!pad_data) {
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printf("Error: Memory allocation failed\n");
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free(padded_data);
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fclose(pad_file);
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free(pad_chksum);
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return 1;
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}
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if (fread(pad_data, 1, chunk_size, pad_file) != chunk_size) {
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printf("Error: Cannot read pad data\n");
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free(padded_data);
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free(pad_data);
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fclose(pad_file);
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free(pad_chksum);
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return 1;
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}
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fclose(pad_file);
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// Encrypt padded data
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unsigned char* encrypted_data = malloc(chunk_size);
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if (!encrypted_data) {
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printf("Error: Memory allocation failed\n");
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free(padded_data);
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free(pad_data);
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free(pad_chksum);
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return 1;
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}
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if (universal_xor_operation(padded_data, chunk_size, pad_data, encrypted_data) != 0) {
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printf("Error: Encryption operation failed\n");
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free(padded_data);
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free(pad_data);
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free(encrypted_data);
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free(pad_chksum);
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return 1;
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}
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free(padded_data);
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free(pad_data);
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// Write output file
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if (ascii_armor) {
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// ASCII armored format - same as message format
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@@ -893,9 +965,9 @@ int encrypt_file(const char* pad_identifier, const char* input_file, const char*
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return 1;
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}
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// Use universal ASCII armor generator
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// Use universal ASCII armor generator (now with chunk_size)
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char* ascii_output;
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if (generate_ascii_armor(pad_chksum, current_offset, encrypted_data, file_size, &ascii_output) != 0) {
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if (generate_ascii_armor(pad_chksum, current_offset, encrypted_data, chunk_size, &ascii_output) != 0) {
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printf("Error: Failed to generate ASCII armor\n");
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fclose(output_fp);
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free(encrypted_data);
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@@ -941,17 +1013,17 @@ int encrypt_file(const char* pad_identifier, const char* input_file, const char*
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uint32_t file_mode = input_stat.st_mode;
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fwrite(&file_mode, sizeof(uint32_t), 1, output_fp);
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// File size: 8 bytes
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// File size: 8 bytes (original file size, not padded)
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fwrite(&file_size, sizeof(uint64_t), 1, output_fp);
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// Encrypted data
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fwrite(encrypted_data, 1, file_size, output_fp);
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// Encrypted data (padded)
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fwrite(encrypted_data, 1, chunk_size, output_fp);
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fclose(output_fp);
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}
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// Update state offset
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if (write_state_offset(pad_chksum, current_offset + file_size) != 0) {
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// Update state offset (now using chunk_size)
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if (write_state_offset(pad_chksum, current_offset + chunk_size) != 0) {
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printf("Warning: Failed to update state file\n");
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}
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@@ -1012,14 +1084,14 @@ int decrypt_binary_file(FILE* input_fp, const char* output_file) {
|
||||
unsigned char pad_chksum_bin[32];
|
||||
uint64_t pad_offset;
|
||||
uint32_t file_mode;
|
||||
uint64_t file_size;
|
||||
uint64_t original_file_size;
|
||||
|
||||
if (fread(magic, 1, 4, input_fp) != 4 ||
|
||||
fread(&version, sizeof(uint16_t), 1, input_fp) != 1 ||
|
||||
fread(pad_chksum_bin, 1, 32, input_fp) != 32 ||
|
||||
fread(&pad_offset, sizeof(uint64_t), 1, input_fp) != 1 ||
|
||||
fread(&file_mode, sizeof(uint32_t), 1, input_fp) != 1 ||
|
||||
fread(&file_size, sizeof(uint64_t), 1, input_fp) != 1) {
|
||||
fread(&original_file_size, sizeof(uint64_t), 1, input_fp) != 1) {
|
||||
printf("Error: Cannot read binary header\n");
|
||||
fclose(input_fp);
|
||||
return 1;
|
||||
@@ -1039,7 +1111,7 @@ int decrypt_binary_file(FILE* input_fp, const char* output_file) {
|
||||
pad_chksum_hex[64] = '\0';
|
||||
|
||||
printf("Decrypting binary file...\n");
|
||||
printf("File size: %lu bytes\n", file_size);
|
||||
printf("Original file size: %lu bytes\n", original_file_size);
|
||||
|
||||
// Check if we have the required pad
|
||||
char pad_path[MAX_HASH_LENGTH + 20];
|
||||
@@ -1064,9 +1136,18 @@ int decrypt_binary_file(FILE* input_fp, const char* output_file) {
|
||||
output_file = default_output;
|
||||
}
|
||||
|
||||
// Read encrypted data
|
||||
unsigned char* encrypted_data = malloc(file_size);
|
||||
if (fread(encrypted_data, 1, file_size, input_fp) != file_size) {
|
||||
// Calculate chunk size (encrypted data is padded)
|
||||
size_t chunk_size = calculate_chunk_size(original_file_size);
|
||||
|
||||
// Read encrypted (padded) data
|
||||
unsigned char* encrypted_data = malloc(chunk_size);
|
||||
if (!encrypted_data) {
|
||||
printf("Error: Memory allocation failed\n");
|
||||
fclose(input_fp);
|
||||
return 1;
|
||||
}
|
||||
|
||||
if (fread(encrypted_data, 1, chunk_size, input_fp) != chunk_size) {
|
||||
printf("Error: Cannot read encrypted data\n");
|
||||
free(encrypted_data);
|
||||
fclose(input_fp);
|
||||
@@ -1089,8 +1170,15 @@ int decrypt_binary_file(FILE* input_fp, const char* output_file) {
|
||||
return 1;
|
||||
}
|
||||
|
||||
unsigned char* pad_data = malloc(file_size);
|
||||
if (fread(pad_data, 1, file_size, pad_file) != file_size) {
|
||||
unsigned char* pad_data = malloc(chunk_size);
|
||||
if (!pad_data) {
|
||||
printf("Error: Memory allocation failed\n");
|
||||
free(encrypted_data);
|
||||
fclose(pad_file);
|
||||
return 1;
|
||||
}
|
||||
|
||||
if (fread(pad_data, 1, chunk_size, pad_file) != chunk_size) {
|
||||
printf("Error: Cannot read pad data\n");
|
||||
free(encrypted_data);
|
||||
free(pad_data);
|
||||
@@ -1100,26 +1188,40 @@ int decrypt_binary_file(FILE* input_fp, const char* output_file) {
|
||||
fclose(pad_file);
|
||||
|
||||
// Use universal XOR operation for decryption
|
||||
if (universal_xor_operation(encrypted_data, file_size, pad_data, encrypted_data) != 0) {
|
||||
if (universal_xor_operation(encrypted_data, chunk_size, pad_data, encrypted_data) != 0) {
|
||||
printf("Error: Decryption operation failed\n");
|
||||
free(encrypted_data);
|
||||
free(pad_data);
|
||||
return 1;
|
||||
}
|
||||
|
||||
// Write decrypted file
|
||||
free(pad_data);
|
||||
|
||||
// Remove padding to get original file
|
||||
size_t actual_file_size;
|
||||
if (remove_padme_padding(encrypted_data, chunk_size, &actual_file_size) != 0) {
|
||||
printf("Error: Invalid padding - file may be corrupted\n");
|
||||
free(encrypted_data);
|
||||
return 1;
|
||||
}
|
||||
|
||||
// Verify the actual size matches the stored original size
|
||||
if (actual_file_size != original_file_size) {
|
||||
printf("Warning: Decrypted size (%lu) doesn't match stored size (%lu)\n",
|
||||
actual_file_size, original_file_size);
|
||||
}
|
||||
|
||||
// Write decrypted file (using actual_file_size)
|
||||
FILE* output_fp = fopen(output_file, "wb");
|
||||
if (!output_fp) {
|
||||
printf("Error: Cannot create output file %s\n", output_file);
|
||||
free(encrypted_data);
|
||||
free(pad_data);
|
||||
return 1;
|
||||
}
|
||||
|
||||
if (fwrite(encrypted_data, 1, file_size, output_fp) != file_size) {
|
||||
if (fwrite(encrypted_data, 1, actual_file_size, output_fp) != actual_file_size) {
|
||||
printf("Error: Cannot write decrypted data\n");
|
||||
free(encrypted_data);
|
||||
free(pad_data);
|
||||
fclose(output_fp);
|
||||
return 1;
|
||||
}
|
||||
@@ -1141,7 +1243,6 @@ int decrypt_binary_file(FILE* input_fp, const char* output_file) {
|
||||
|
||||
// Cleanup
|
||||
free(encrypted_data);
|
||||
free(pad_data);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
12
src/main.h
12
src/main.h
@@ -23,7 +23,7 @@
|
||||
#include <ctype.h>
|
||||
|
||||
// Version - Updated automatically by build.sh
|
||||
#define OTP_VERSION "v0.3.47"
|
||||
#define OTP_VERSION "v0.3.48"
|
||||
|
||||
// Constants
|
||||
#define MAX_INPUT_SIZE 4096
|
||||
@@ -267,6 +267,16 @@ const char* get_files_directory(void);
|
||||
void get_default_file_path(const char* filename, char* result_path, size_t result_size);
|
||||
void get_directory_display(const char* file_path, char* result, size_t result_size);
|
||||
|
||||
////////////////////////////////////////////////////////////////////////////////
|
||||
// MESSAGE PADDING FUNCTIONS
|
||||
////////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
// Exponential bucketing and ISO/IEC 9797-1 Method 2 (Padmé) padding
|
||||
size_t calculate_chunk_size(size_t msg_len);
|
||||
int apply_padme_padding(unsigned char* buffer, size_t msg_len, size_t chunk_size);
|
||||
int remove_padme_padding(const unsigned char* buffer, size_t chunk_size, size_t* msg_len);
|
||||
void format_chunk_size(size_t chunk_size, char* buffer, size_t buffer_size);
|
||||
|
||||
////////////////////////////////////////////////////////////////////////////////
|
||||
// UTILITY FUNCTIONS
|
||||
////////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
92
src/padding.c
Normal file
92
src/padding.c
Normal file
@@ -0,0 +1,92 @@
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
#include <stdint.h>
|
||||
#include "main.h"
|
||||
|
||||
////////////////////////////////////////////////////////////////////////////////
|
||||
// MESSAGE PADDING IMPLEMENTATION
|
||||
// ISO/IEC 9797-1 Method 2 (Padmé Padding)
|
||||
// with Exponential Bucketing for Traffic Analysis Resistance
|
||||
////////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
// Calculate required chunk size using exponential bucketing
|
||||
// Starting at 256 bytes, doubling each time
|
||||
// Provides strong protection against length analysis attacks
|
||||
size_t calculate_chunk_size(size_t msg_len) {
|
||||
size_t chunk = 256; // Minimum chunk size: 256 bytes
|
||||
|
||||
// Need space for message + 0x80 byte (minimum 1 byte padding)
|
||||
while (chunk < msg_len + 1) {
|
||||
chunk *= 2;
|
||||
}
|
||||
|
||||
return chunk;
|
||||
}
|
||||
|
||||
// Apply ISO/IEC 9797-1 Method 2 (Padmé) padding
|
||||
// Appends 0x80 byte followed by 0x00 bytes to reach chunk boundary
|
||||
// Returns 0 on success, non-zero on error
|
||||
int apply_padme_padding(unsigned char* buffer, size_t msg_len, size_t chunk_size) {
|
||||
if (!buffer) {
|
||||
return 1; // Error: null pointer
|
||||
}
|
||||
|
||||
if (chunk_size < msg_len + 1) {
|
||||
return 2; // Error: chunk size too small for message + padding
|
||||
}
|
||||
|
||||
// Apply padding: 0x80 followed by 0x00 bytes
|
||||
buffer[msg_len] = 0x80;
|
||||
|
||||
// Fill remaining bytes with 0x00
|
||||
if (chunk_size > msg_len + 1) {
|
||||
memset(buffer + msg_len + 1, 0x00, chunk_size - msg_len - 1);
|
||||
}
|
||||
|
||||
return 0; // Success
|
||||
}
|
||||
|
||||
// Remove ISO/IEC 9797-1 Method 2 (Padmé) padding
|
||||
// Scans backwards for 0x80 marker, validates padding
|
||||
// Returns 0 on success, non-zero on error
|
||||
// Sets msg_len to the actual message length (excluding padding)
|
||||
int remove_padme_padding(const unsigned char* buffer, size_t chunk_size, size_t* msg_len) {
|
||||
if (!buffer || !msg_len) {
|
||||
return 1; // Error: null pointer
|
||||
}
|
||||
|
||||
if (chunk_size == 0) {
|
||||
return 2; // Error: invalid chunk size
|
||||
}
|
||||
|
||||
// Scan backwards from end to find 0x80 marker
|
||||
for (int i = chunk_size - 1; i >= 0; i--) {
|
||||
if (buffer[i] == 0x80) {
|
||||
// Found the padding marker
|
||||
*msg_len = i;
|
||||
return 0; // Success
|
||||
} else if (buffer[i] != 0x00) {
|
||||
// Found non-zero, non-0x80 byte - invalid padding
|
||||
return 3; // Error: invalid padding (corrupted or tampered data)
|
||||
}
|
||||
}
|
||||
|
||||
// No 0x80 marker found - invalid padding
|
||||
return 4; // Error: no padding marker found
|
||||
}
|
||||
|
||||
// Helper function to get human-readable chunk size
|
||||
// Useful for debugging and user feedback
|
||||
void format_chunk_size(size_t chunk_size, char* buffer, size_t buffer_size) {
|
||||
if (!buffer || buffer_size == 0) return;
|
||||
|
||||
if (chunk_size < 1024) {
|
||||
snprintf(buffer, buffer_size, "%zu bytes", chunk_size);
|
||||
} else if (chunk_size < 1024 * 1024) {
|
||||
snprintf(buffer, buffer_size, "%.1f KB", chunk_size / 1024.0);
|
||||
} else if (chunk_size < 1024 * 1024 * 1024) {
|
||||
snprintf(buffer, buffer_size, "%.1f MB", chunk_size / (1024.0 * 1024.0));
|
||||
} else {
|
||||
snprintf(buffer, buffer_size, "%.1f GB", chunk_size / (1024.0 * 1024.0 * 1024.0));
|
||||
}
|
||||
}
|
||||
129
tests/test_padding.sh
Executable file
129
tests/test_padding.sh
Executable file
@@ -0,0 +1,129 @@
|
||||
#!/bin/bash
|
||||
# Test script for message padding implementation
|
||||
|
||||
set -e
|
||||
|
||||
echo "=== Testing Message Padding Implementation ==="
|
||||
echo ""
|
||||
|
||||
# Colors
|
||||
GREEN='\033[0;32m'
|
||||
RED='\033[0;31m'
|
||||
NC='\033[0m' # No Color
|
||||
|
||||
# Test counter
|
||||
TESTS_PASSED=0
|
||||
TESTS_FAILED=0
|
||||
|
||||
# Function to run a test
|
||||
run_test() {
|
||||
local test_name="$1"
|
||||
local test_command="$2"
|
||||
|
||||
echo -n "Testing: $test_name... "
|
||||
if eval "$test_command" > /dev/null 2>&1; then
|
||||
echo -e "${GREEN}PASS${NC}"
|
||||
((TESTS_PASSED++))
|
||||
return 0
|
||||
else
|
||||
echo -e "${RED}FAIL${NC}"
|
||||
((TESTS_FAILED++))
|
||||
return 1
|
||||
fi
|
||||
}
|
||||
|
||||
# Create a small test pad if it doesn't exist
|
||||
if [ ! -f "pads/"*.pad ]; then
|
||||
echo "Creating test pad (1MB)..."
|
||||
./build/otp-x86_64 generate 1MB
|
||||
echo ""
|
||||
fi
|
||||
|
||||
# Get the first pad checksum
|
||||
PAD_CHKSUM=$(ls pads/*.pad | head -n 1 | xargs basename | sed 's/.pad$//')
|
||||
|
||||
echo "Using pad: ${PAD_CHKSUM:0:16}..."
|
||||
echo ""
|
||||
|
||||
# Test 1: Encrypt and decrypt a short message (should be padded to 256 bytes)
|
||||
echo "Test 1: Short message (10 bytes -> 256 bytes padded)"
|
||||
TEST_MSG="Hello Test"
|
||||
ENCRYPTED=$(echo "$TEST_MSG" | ./build/otp-x86_64 encrypt ${PAD_CHKSUM:0:8})
|
||||
DECRYPTED=$(echo "$ENCRYPTED" | ./build/otp-x86_64 decrypt)
|
||||
|
||||
if [ "$DECRYPTED" = "$TEST_MSG" ]; then
|
||||
echo -e "${GREEN}✓ Short message encryption/decryption successful${NC}"
|
||||
((TESTS_PASSED++))
|
||||
else
|
||||
echo -e "${RED}✗ Short message failed${NC}"
|
||||
echo " Expected: $TEST_MSG"
|
||||
echo " Got: $DECRYPTED"
|
||||
((TESTS_FAILED++))
|
||||
fi
|
||||
echo ""
|
||||
|
||||
# Test 2: Encrypt and decrypt a medium message (should be padded to 512 bytes)
|
||||
echo "Test 2: Medium message (~300 bytes -> 512 bytes padded)"
|
||||
TEST_MSG=$(printf 'A%.0s' {1..300})
|
||||
ENCRYPTED=$(echo "$TEST_MSG" | ./build/otp-x86_64 encrypt ${PAD_CHKSUM:0:8})
|
||||
DECRYPTED=$(echo "$ENCRYPTED" | ./build/otp-x86_64 decrypt)
|
||||
|
||||
if [ "$DECRYPTED" = "$TEST_MSG" ]; then
|
||||
echo -e "${GREEN}✓ Medium message encryption/decryption successful${NC}"
|
||||
((TESTS_PASSED++))
|
||||
else
|
||||
echo -e "${RED}✗ Medium message failed${NC}"
|
||||
((TESTS_FAILED++))
|
||||
fi
|
||||
echo ""
|
||||
|
||||
# Test 3: Encrypt and decrypt with special characters
|
||||
echo "Test 3: Special characters and unicode"
|
||||
TEST_MSG="Hello! @#$%^&*() 测试"
|
||||
ENCRYPTED=$(echo "$TEST_MSG" | ./build/otp-x86_64 encrypt ${PAD_CHKSUM:0:8})
|
||||
DECRYPTED=$(echo "$ENCRYPTED" | ./build/otp-x86_64 decrypt)
|
||||
|
||||
if [ "$DECRYPTED" = "$TEST_MSG" ]; then
|
||||
echo -e "${GREEN}✓ Special characters encryption/decryption successful${NC}"
|
||||
((TESTS_PASSED++))
|
||||
else
|
||||
echo -e "${RED}✗ Special characters failed${NC}"
|
||||
echo " Expected: $TEST_MSG"
|
||||
echo " Got: $DECRYPTED"
|
||||
((TESTS_FAILED++))
|
||||
fi
|
||||
echo ""
|
||||
|
||||
# Test 4: File encryption/decryption with padding
|
||||
echo "Test 4: File encryption/decryption"
|
||||
TEST_FILE="/tmp/otp_test_file.txt"
|
||||
echo "This is a test file for OTP encryption with padding." > "$TEST_FILE"
|
||||
|
||||
./build/otp-x86_64 -f "$TEST_FILE" ${PAD_CHKSUM:0:8} -a -o /tmp/test_encrypted.otp.asc
|
||||
./build/otp-x86_64 decrypt /tmp/test_encrypted.otp.asc -o /tmp/test_decrypted.txt
|
||||
|
||||
if diff "$TEST_FILE" /tmp/test_decrypted.txt > /dev/null 2>&1; then
|
||||
echo -e "${GREEN}✓ File encryption/decryption successful${NC}"
|
||||
((TESTS_PASSED++))
|
||||
else
|
||||
echo -e "${RED}✗ File encryption/decryption failed${NC}"
|
||||
((TESTS_FAILED++))
|
||||
fi
|
||||
|
||||
# Cleanup
|
||||
rm -f "$TEST_FILE" /tmp/test_encrypted.otp.asc /tmp/test_decrypted.txt
|
||||
echo ""
|
||||
|
||||
# Summary
|
||||
echo "=== Test Summary ==="
|
||||
echo -e "Tests passed: ${GREEN}${TESTS_PASSED}${NC}"
|
||||
echo -e "Tests failed: ${RED}${TESTS_FAILED}${NC}"
|
||||
echo ""
|
||||
|
||||
if [ $TESTS_FAILED -eq 0 ]; then
|
||||
echo -e "${GREEN}All tests passed!${NC}"
|
||||
exit 0
|
||||
else
|
||||
echo -e "${RED}Some tests failed.${NC}"
|
||||
exit 1
|
||||
fi
|
||||
Reference in New Issue
Block a user