Version v0.2.7 - Automatic version increment

README.md

@@ -1,4 +1,4 @@
-# OTP Cipher - One Time Pad Implementation
+r# OTP Cipher - One Time Pad Implementation
 
 A secure one-time pad (OTP) cipher implementation in C with automatic versioning system.
 

build.sh

@@ -50,6 +50,20 @@ increment_version() {
     print_status "Current version: $LATEST_TAG"
     print_status "New version: $NEW_VERSION"
     
+    # Stage all changes
+    if git add . 2>/dev/null; then
+        print_success "Staged all changes"
+    else
+        print_warning "Failed to stage changes (maybe not a git repository)"
+    fi
+    
+    # Commit changes with version message
+    if git commit -m "Version $NEW_VERSION - Automatic version increment" 2>/dev/null; then
+        print_success "Committed changes for version $NEW_VERSION"
+    else
+        print_warning "Failed to commit changes (maybe no changes to commit or not a git repository)"
+    fi
+    
     # Create new git tag
     if git tag "$NEW_VERSION" 2>/dev/null; then
         print_success "Created new version tag: $NEW_VERSION"

otp.c

@@ -75,7 +75,7 @@ void show_progress(uint64_t current, uint64_t total, time_t start_time);
 // File operations
 int read_state_offset(const char* pad_hash, uint64_t* offset);
 int write_state_offset(const char* pad_hash, uint64_t offset);
-int calculate_sha256(const char* filename, char* hash_hex);
+int calculate_checksum(const char* filename, char* checksum_hex);
 void xor_checksum_256(const unsigned char* data, size_t len, unsigned char checksum[32]);
 char* custom_base64_encode(const unsigned char* input, int length);
 unsigned char* custom_base64_decode(const char* input, int* output_length);
@@ -117,7 +117,7 @@ int interactive_mode(void) {
                 list_available_pads();
                 break;
             case 5: {
-                printf("Enter pad hash (or prefix): ");
+                printf("Enter pad checksum (or prefix): ");
                 char input[MAX_HASH_LENGTH];
                 if (fgets(input, sizeof(input), stdin)) {
                     input[strcspn(input, "\n")] = 0;
@@ -559,9 +559,9 @@ int generate_pad(uint64_t size_bytes, int display_progress) {
     fclose(urandom);
     fclose(pad_file);
     
-    // Calculate SHA-256 of the pad file
-    if (calculate_sha256(temp_filename, hash_hex) != 0) {
-        printf("Error: Cannot calculate pad hash\n");
+    // Calculate XOR checksum of the pad file
+    if (calculate_checksum(temp_filename, hash_hex) != 0) {
+        printf("Error: Cannot calculate pad checksum\n");
         unlink(temp_filename);
         return 1;
     }
@@ -743,9 +743,9 @@ int generate_pad_with_entropy(uint64_t size_bytes, int display_progress, int use
     fclose(urandom);
     fclose(pad_file);
     
-    // Calculate SHA-256 of the pad file
-    if (calculate_sha256(temp_filename, hash_hex) != 0) {
-        printf("Error: Cannot calculate pad hash\n");
+    // Calculate XOR checksum of the pad file
+    if (calculate_checksum(temp_filename, hash_hex) != 0) {
+        printf("Error: Cannot calculate pad checksum\n");
         unlink(temp_filename);
         return 1;
     }
@@ -764,11 +764,11 @@ int generate_pad_with_entropy(uint64_t size_bytes, int display_progress, int use
         printf("Warning: Cannot set pad file to read-only\n");
     }
     
-    // Initialize state file with offset 0
+    // Initialize state file with offset 32 (first 32 bytes used for checksum encryption)
     FILE* state_file = fopen(state_path, "wb");
     if (state_file) {
-        uint64_t zero = 0;
-        fwrite(&zero, sizeof(uint64_t), 1, state_file);
+        uint64_t reserved_bytes = 32;
+        fwrite(&reserved_bytes, sizeof(uint64_t), 1, state_file);
         fclose(state_file);
     } else {
         printf("Error: Failed to create state file\n");
@@ -778,7 +778,7 @@ int generate_pad_with_entropy(uint64_t size_bytes, int display_progress, int use
     
     double size_gb = (double)size_bytes / (1024.0 * 1024.0 * 1024.0);
     printf("Generated pad: %s (%.2f GB)\n", pad_path, size_gb);
-    printf("Pad hash: %s\n", hash_hex);
+    printf("Pad checksum: %s\n", hash_hex);
     printf("State file: %s\n", state_path);
     if (use_keyboard_entropy) {
         printf("Enhanced with keyboard entropy!\n");
@@ -816,9 +816,18 @@ int encrypt_text(const char* pad_identifier) {
         return 1;
     }
     
-    // Calculate SHA-256 of pad file
-    if (calculate_sha256(pad_path, hash_hex) != 0) {
-        printf("Error: Cannot calculate pad hash\n");
+    // Ensure we never encrypt before offset 32 (reserved for checksum encryption)
+    if (current_offset < 32) {
+        printf("Warning: State offset below reserved area, adjusting to 32\n");
+        current_offset = 32;
+        if (write_state_offset(pad_hash, current_offset) != 0) {
+            printf("Warning: Failed to update state file\n");
+        }
+    }
+    
+    // Calculate XOR checksum of pad file
+    if (calculate_checksum(pad_path, hash_hex) != 0) {
+        printf("Error: Cannot calculate pad checksum\n");
         free(pad_hash);
         return 1;
     }
@@ -988,8 +997,8 @@ int decrypt_text(const char* pad_identifier) {
     }
     
     // Verify pad integrity
-    if (calculate_sha256(pad_path, current_hash) != 0) {
-        printf("Error: Cannot calculate current pad hash\n");
+    if (calculate_checksum(pad_path, current_hash) != 0) {
+        printf("Error: Cannot calculate current pad checksum\n");
         return 1;
     }
     
@@ -1098,7 +1107,7 @@ int write_state_offset(const char* pad_hash, uint64_t offset) {
     return 0;
 }
 
-int calculate_sha256(const char* filename, char* hash_hex) {
+int calculate_checksum(const char* filename, char* checksum_hex) {
     FILE* file = fopen(filename, "rb");
     if (!file) {
         return 1;
@@ -1142,9 +1151,9 @@ int calculate_sha256(const char* filename, char* hash_hex) {
     
     // Convert to hex string (64 characters)
     for (int i = 0; i < 32; i++) {
-        sprintf(hash_hex + (i * 2), "%02x", encrypted_checksum[i]);
+        sprintf(checksum_hex + (i * 2), "%02x", encrypted_checksum[i]);
     }
-    hash_hex[64] = '\0';
+    checksum_hex[64] = '\0';
     
     return 0;
 }
@@ -1329,8 +1338,8 @@ void print_usage(const char* program_name) {
     printf("Usage:\n");
     printf("  %s                              - Interactive mode\n", program_name);
     printf("  %s generate <size>              - Generate new pad\n", program_name);
-    printf("  %s encrypt <pad_hash_prefix>    - Encrypt text\n", program_name);
-    printf("  %s decrypt <pad_hash_prefix>    - Decrypt message\n", program_name);
+    printf("  %s encrypt <pad_checksum_prefix> - Encrypt text\n", program_name);
+    printf("  %s decrypt <pad_checksum_prefix> - Decrypt message\n", program_name);
     printf("  %s list                         - List available pads\n", program_name);
     printf("\nSize examples: 1GB, 5TB, 512MB, 2048 (bytes)\n");
     printf("Pad selection: Full hash, prefix, or number from list\n");