Added exponential padding to increase security.

tests/test_padding.sh

@@ -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