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Author: javascript-2020

blog/25-12-19/diffie-hellman/ex/tiny-encrypt2.js

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+
+
+
+//  key >>> message
+
+
+        var tiny        = {};        
+
+        
+        tiny.encrypt    = (message,key)=>{
+    
+              message   = [...message];
+              var n   = key.length;
+              for(var i=0;i<n;i++){
+                
+                    var k         = key[i];
+                    var mi        = i%message.length;
+                    var c         = message[mi];
+                    var byte      = tiny.code(c)^tiny.code(k);
+                    var e         = tiny.char(byte);
+                    message[mi]   = e;
+                                                                                console.log(i,k,mi,c,byte,e);
+                    //[...message].reduce((a,c,i)=>a+tiny.xor(c,key,i),'')
+                    
+              }//for
+              
+              message   = message.join('');
+              var b64   = btoa(message);
+              return b64;
+              
+        }//encrypt
+        
+        
+        tiny.decrypt    = (encrypted,key)=>{
+          
+              encrypted   = atob(encrypted);
+              encrypted   = [...encrypted];
+              var n       = key.length;
+              for(var i=0;i<n;i++){
+                
+                    var ei    = i%encrypted.length;
+                    var e     = encrypted[ei];
+                    var k     = key[i];
+                    var byte    = tiny.code(e)^tiny.code(k);
+                    var c       = tiny.char(byte);
+                    encrypted[ei]   = c;
+                    
+                    //[...atob(encrypted)].reduce((a,e,i)=>a+tiny.xor(e,key,i),'')
+                    
+              }//for
+              
+              encrypted     = encrypted.join('');
+              var message   = encrypted;
+              return message;
+                
+        }//decrypt
+        
+        
+        tiny.xor        = (c,key,i)=>tiny.char(tiny.code(c)^tiny.code(key[i%key.length]));
+        tiny.code       = v=>v.charCodeAt(0);
+        tiny.char       = v=>String.fromCharCode(v);        
+
+
+        var key         = '1234567890xyz';
+        var encrypted   = tiny.encrypt('hello',key)
+        console.log(encrypted);      
+        
+        var decrypted   = tiny.decrypt(encrypted,key);
+        console.log(decrypted);
+
+
+
+
+