(ql:quickload :cl-base64)
(ql:quickload :iterate)

(use-package :iterate)

(defun hex-to-dec (hex-chr)
  (cond
    ((char<= #\0 hex-chr #\9)
     (- (char-code hex-chr) (char-code #\0)))
    ((char<= #\a hex-chr #\f)
     (+ (- (char-code hex-chr) (char-code #\a)) 10))
    ((char<= #\A hex-chr #\F)
     (+ (- (char-code hex-chr) (char-code #\A)) 10))))

(defun hex-to-bytes (hex-str)
  (iter
    (for i below (length hex-str) by 2)
    (let ((c1 (hex-to-dec (aref hex-str i)))
          (c2 (hex-to-dec (aref hex-str (1+ i)))))
        (collect (+ (* 16 c1) c2) result-type (vector (unsigned-byte 8)))))) 

;; set 1 challenge 1
(defun hex-to-base64 (hex-str)
  (cl-base64:usb8-array-to-base64-string (hex-to-bytes hex-str)))