Fixed bug in nip44.c, was an error in ecdh_shared_secret. Added comments

tests/nip44_test.c

@@ -83,12 +83,6 @@ static int hex_to_bytes(const char* hex, unsigned char* bytes, size_t len) {
     return 0;
 }
 
-static void bytes_to_hex(const unsigned char* bytes, size_t len, char* hex) {
-    for (size_t i = 0; i < len; i++) {
-        sprintf(hex + i * 2, "%02x", bytes[i]);
-    }
-    hex[len * 2] = '\0';
-}
 
 static int test_nip44_round_trip(const nip44_test_vector_t* tv) {
     printf("Test: %s\n", tv->name);
@@ -364,31 +358,39 @@ int main() {
     size_t num_vectors = sizeof(test_vectors) / sizeof(test_vectors[0]);
     for (size_t i = 0; i < num_vectors; i++) {
         total_tests++;
+        printf("Test #%d\n", total_tests);
         if (test_nip44_round_trip(&test_vectors[i]) == 0) {
             passed_tests++;
         }
+        printf("\n");
     }
     
     // Test decryption vectors (cross-compatibility)
     size_t num_decryption_vectors = sizeof(decryption_test_vectors) / sizeof(decryption_test_vectors[0]);
     for (size_t i = 0; i < num_decryption_vectors; i++) {
         total_tests++;
+        printf("Test #%d\n", total_tests);
         if (test_nip44_decryption_vector(&decryption_test_vectors[i]) == 0) {
             passed_tests++;
         }
+        printf("\n");
     }
     
     // Test encryption variability (NIP-44 non-deterministic behavior)
     total_tests++;
+    printf("Test #%d\n", total_tests);
     if (test_nip44_encryption_variability() == 0) {
         passed_tests++;
     }
+    printf("\n");
     
     // Test error conditions
     total_tests++;
+    printf("Test #%d\n", total_tests);
     if (test_nip44_error_conditions() == 0) {
         passed_tests++;
     }
+    printf("\n");
     
     // Final results
     printf("\nTest Results: %d/%d passed\n", passed_tests, total_tests);