June 2018 Update

Task/Vigen-re-cipher/VBScript/vigen-re-cipher-2.vb

@@ -0,0 +1,34 @@
+'vigenere cypher
+option explicit
+const asca =65  'ascii(a)
+
+function filter(s)
+    with new regexp
+      .pattern="[^A-Z]"
+      .global=1
+      filter=.replace(ucase(s),"")
+     end with
+end function
+
+function vigenere (s,k,sign)
+dim s1,i,a,b
+  for i=0 to len(s)-1
+    a=asc(mid(s,i+1,1))-asca
+    b=sign * (asc(mid(k,(i mod len(k))+1,1))-asca)
+    s1=s1 & chr(((a+b+26) mod 26) +asca)
+  next
+  vigenere=s1
+end function
+
+function encrypt(s,k): encrypt=vigenere(s,k,1) :end function
+function decrypt(s,k): decrypt=vigenere(s,k,-1) :end function
+
+'test--------------------------
+dim plaintext,filtered,key,encoded
+key="VIGENERECYPHER"
+plaintext = "Beware the Jabberwock, my son! The jaws that bite, the claws that catch!"
+filtered= filter(plaintext)
+wscript.echo filtered
+encoded=encrypt(filtered,key)
+wscript.echo encoded
+wscript.echo decrypt(encoded,key)