crypt core code

src/Crypt.cpp

@@ -33,16 +33,25 @@ std::string Crypt::cesar( std::string sentances, int key, char start, char end )
 std::string Crypt::vigenere( std::string sentance, std::string key, char start, char end ){
   std::string result = "";
   int k = 0;
-  int count = 1;
 
-  for( char character : sentance ){
-    k = alphabetIndex( loopInString( key, count++ ), start, end);
-    result += Crypt::replaceChar( character, k, start, end ) ;
+  const char* c_sentance = sentance.c_str();
+
+  for( int count = 0 ;  count < (int)sentance.length(); count++ ){
+    char character = c_sentance[ count ] ;
+    k = alphabetIndex( loopInString( key, count+1 ), start, end);
+
+    if( k == 0 ){
+      result += character;
+    }else{
+      result += Crypt::replaceChar( character, k, start, end ) ;
+    }
   }
-  
+
   return result;
 }
 
+/**
+ **/
 std::string Crypt::atbash( std::string sentance, char start, char end ){
   std::string result = "";
   int k = 0;
@@ -56,27 +65,26 @@ std::string Crypt::atbash( std::string sentance, char start, char end ){
       result += character;
     }
   }
-  
+
   return result;
 }
 
 /** replaceChar
  @brief replace a character with the next character at key distance in the alphabetical order, and loop at z.
- @parameter char ch, the chasacter to replace
+ @parameter char ch, the character to replace
  @parameter int key, the distance to look at
  @return string, the replacement character
  **/
 char Crypt::replaceChar( char ch, int key, char start, char end ){
   ch = (char)std::tolower( ch );
-  int max = (int)end;
+  int max = (int)end ;
 
   if( !Crypt::isLetter( ch, start, end ) ){
     return ch;
   }
-  
-  if( (ch + key) > max ){
-    key -= (max - (int)ch);
-    ch = start;
+
+  if( ( (int)ch + key) > max ){
+    key -= (int)end - (int)start + 1;
   }
 
   return (char)((int)ch + key);
@@ -87,9 +95,10 @@ char Crypt::replaceChar( char ch, int key, char start, char end ){
  @return char
  **/
 char Crypt::loopInString( std::string str, int key ){
+  
   key -= ((int)str.length() < key )? str.length() : 0 ;
 
-  return str.c_str()[ key - 1 ];
+  return (Crypt::isLetter( str.c_str()[ key - 1 ] ))? str.c_str()[ key - 1 ] : 0 ;
 }
 
 /** alphabetIndex
@@ -113,7 +122,7 @@ int Crypt::alphabetIndex( char ch, char start, char end ){
  **/
 bool Crypt::isLetter( char ch, char start, char end ){
   ch = (char)std::tolower( ch );
-
+  
   if(( (int)ch < (int)start ) || ( (int)ch > (int)end )){
     return false;
   }