rigor

lib/src/whatfreewords_scrambler.dart

@@ -1,7 +1,7 @@
 import 'dart:math';
 import 'whatfreewords_cipher.dart';
 
-Map<String, String> ilist = 
+final Map<String, String> ilist = 
     wlist.map((key, value) => MapEntry(value, key));
 
 String f(String L, String R) {
@@ -19,6 +19,11 @@ String f(String L, String R) {
     "2807694315",
     "8746293105"
   ];
+  
+  if (x < 0 || x >= 10 || y < 0 || y >= 10) {
+    throw RangeError("Index out of bounds: x=$x, y=$y");
+  }
+  
   return block[y][x];
 }
 
@@ -26,10 +31,15 @@ String F(String L, String K) {
   int x = int.parse(L);
   int k = int.parse(K);
   String temp = "${x * x * x * k * 3 + 23 * k * k * x * x * x + k * (x + k) + 3}";
+
+  temp = temp.padLeft(10, '0');
+
   return temp.substring(4, 10);
 }
 
 String feistPass(String input, String k) {
+  assert(input.length == 12, "Input to feistPass must be 12 characters long");
+  
   String L = input.substring(0, 6);
   String R = input.substring(6, 12);
   String Rout = "";
@@ -58,6 +68,12 @@ String unscrambler(String input) {
 }
 
 String coordToWords(List<double> coordinate) {
+  if (coordinate.length != 2 ||
+      coordinate[0] < -90 || coordinate[0] > 90 ||
+      coordinate[1] < -180 || coordinate[1] > 180) {
+    throw ArgumentError("Invalid coordinate values: $coordinate");
+  }
+  
   int lat = (coordinate[0] * 10000).round() + 900000;
   int lon = (coordinate[1] * 10000).round() + 1800000;
 
@@ -69,25 +85,46 @@ String coordToWords(List<double> coordinate) {
 
   String latlonRest = scrambler(latStr.substring(1, 7) + lonStr.substring(1, 7));
 
-  lat = int.parse(lat0 + latlonRest.substring(0, 6));
-  lon = int.parse(lon0 + latlonRest.substring(6, 12));
+  lat = int.parse(lat0 + latlonRest.substring(0, 6).padRight(6, '0'));
+  lon = int.parse(lon0 + latlonRest.substring(6, 12).padRight(6, '0'));
 
-  String ind1 = lat.toString().substring(0, 5);
-  String ind2 = lon.toString().substring(0, 5);
-  String ind3 = "0" + lat.toString().substring(5, 7) + lon.toString().substring(5, 7);
+  String latString = lat.toString().padLeft(7, '0');
+  String lonString = lon.toString().padLeft(7, '0');
+
+  if (latString.length < 7 || lonString.length < 7) {
+    throw ArgumentError("Coordinate string lengths are incorrect: lat=$latString, lon=$lonString");
+  }
+
+  String ind1 = latString.substring(0, 5);
+  String ind2 = lonString.substring(0, 5);
+  String ind3 = "0" + latString.substring(5, 7) + lonString.substring(5, 7);
 
   return "${wlist[ind1]}.${wlist[ind2]}.${wlist[ind3]}";
 }
 
 List<double> wordsToCoord(String words) {
   List<String> word = words.split(".");
-  String ind1 = ilist[word[0]]!;
-  String ind2 = ilist[word[1]]!;
-  String ind3 = ilist[word[2]]!;
+
+  // Ensure exactly 3 words are provided and each exists in the dictionary
+  if (word.length != 3 || !ilist.containsKey(word[0]) || !ilist.containsKey(word[1]) || !ilist.containsKey(word[2])) {
+    throw ArgumentError("Invalid words format: $words");
+  }
+
+  String? ind1 = ilist[word[0]];
+  String? ind2 = ilist[word[1]];
+  String? ind3 = ilist[word[2]];
+
+  if (ind1 == null || ind2 == null || ind3 == null || ind3.length < 5) {
+    throw ArgumentError("Invalid word mapping for words: $words");
+  }
 
   String lat = ind1 + ind3.substring(1, 3);
   String lon = ind2 + ind3.substring(3, 5);
 
+  if (lat.length < 7 || lon.length < 7) {
+    throw ArgumentError("Malformed coordinate indices: lat=$lat, lon=$lon");
+  }
+
   String latlonRest = lat.substring(1, 7) + lon.substring(1, 7);
   latlonRest = unscrambler(latlonRest);
 
@@ -97,9 +134,15 @@ List<double> wordsToCoord(String words) {
   double latitude = (int.parse(lat) - 900000) / 10000.0;
   double longitude = (int.parse(lon) - 1800000) / 10000.0;
 
+  // Additional validation: Ensure valid latitude/longitude range
+  if (latitude < -90 || latitude > 90 || longitude < -180 || longitude > 180) {
+    throw ArgumentError("Computed coordinates out of range: lat=$latitude, lon=$longitude");
+  }
+
   return [latitude, longitude];
 }
 
+
 void main() {
   List<double> coordinate = [51.50844113, -0.116708278];
   String words = coordToWords(coordinate);