Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.8)
// Compass (v1.0.0.alpha.19)
// ----


// Return a charset string.
// --------
// @param [string] $charset
// --------
// @return [string]

@function charset(
  $charset
) {
  @return map-get((
    numeric:
      '0123456789',
    alphabetic:
      'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz',
    alphanumeric:
      '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz',
    ascii:
      '!"#$%&' + "'" +
      '()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~'
  ), $charset);
}


// Get char at `$index` in `$str`.
// --------
// @param [string] $str
// @param [number] $index
// --------
// @return [string]

@function char-at(
  $str,
  $index: 1
) {
  @return str-slice($str, $index, $index);
}


// Get char code from `$str` at `$index` in range `$charset`.
// --------
// @param [string] $str
// @param [number] $index
// @param [string] $charset
// --------
// @return [number]

@function char-code-at(
  $str,
  $index: 1,
  $charset: alphabetic
) {
  $chars: charset($charset);
  @return str-index($chars, char-at($str, $index));
}


// Get char at `$index` in range `$charset`.
// --------
// @param [number] $index
// @param [string] $charset
// --------
// @return [string]

@function from-char-code(
  $index,
  $charset: alphabetic
) {
  $chars: charset($charset) or $charset;
  @return char-at($chars, $index);
}


// Return a filtered string.
// --------
// @param [string] $str
// --------
// @return [string]

@function str-filter(
  $str,
  $charset: alphabetic
) {
  $chars: charset($charset);
  $result: '';

  @for $i from 1 through str-length($str)  {
    $c: char-at($str, $i);
    @if str-index($chars, $c) {
      $result: $result + $c;
    }
  }

  @return $result;
}



@function otp(
  $message, 
  $key,
  $op: 'encrypt'
) {
  $key: str-filter(to-upper-case($key));
  $result: '';
  
  $j: 1;
  @for $i from 1 through str-length($message)  {
    $c: char-code-at($message, $i);
    $k: char-code-at($key, $j);
    
    @if $c {
      // Uppercase $c <= 26
      // Lowercase $c > 26
      $case: if($c > 26, 26, 0);
      $padded: if($op == 'encrypt', ($c + $k - 2), ($c - $k));
      $padded: (($padded - $case) % 26) + $case + 1;
      $result: $result + from-char-code($padded);
      $j: $j + 1;
    }
    @else {
      // Non [A-Za-z] char.
      $result: $result + char-at($message, $i);
    }
  }
  
  @return $result;
}



tests {
  /* eqnvz */
  t: otp('Hello', 'xmckl'); 
  t: otp('Eqnvz', 'xmckl', 'decrypt'); 
  /* Hllwjg Eooyar */
  t: otp('Berlin Amiens', 'ghulbtecgunz'); 
  t: otp('Hllwjg Eooyar', 'ghulbtecgunz', 'decrypt'); 
  /* Rltsyrg Blqldn */
  t: otp('Gilbert Vernam', 'ldiruanghzydb'); 
  t: otp('Rltsyrg Blqldn', 'ldiruanghzydb', 'decrypt'); 
  /* Rviqx Lcdopi */
  t: otp('Frank Miller', 'meidnzusdlr'); 
  t: otp('Rviqx Lcdopi', 'meidnzusdlr', 'decrypt'); 
}

SassMeister-output.css

tests {
  /* eqnvz */
  t: "Eqnvz";
  t: "Hello";
  /* Hllwjg Eooyar */
  t: "Hllwjg Eooyar";
  t: "Berlin Amiens";
  /* Rltsyrg Blqldn */
  t: "Rltsyrg Blqldn";
  t: "Gilbert Vernam";
  /* Rviqx Lcdopi */
  t: "Rviqx Lcdopi";
  t: "Frank Miller";
}