;;;; Programmer: Kevin M. Rosenberg
;;;; Date Started: Dec 2002
;;;;
-;;;; $Id: decode.lisp,v 1.3 2003/01/14 11:43:10 kevin Exp $
+;;;; $Id$
;;;;
;;;; This file implements the Base64 transfer encoding algorithm as
;;;; defined in RFC 1521 by Borensten & Freed, September 1993.
;;;; Permission to use with BSD-style license included in the COPYING file
;;;; *************************************************************************
-(declaim (optimize (debug 3) (speed 3) (safety 1) (compilation-speed 0)))
-
(in-package #:cl-base64)
-(declaim (inline whitespace-p))
-(defun whitespace-p (c)
- "Returns T for a whitespace character."
- (or (char= c #\Newline) (char= c #\Linefeed)
- (char= c #\Return) (char= c #\Space)
- (char= c #\Tab)))
+(define-condition base64-error (error)
+ ((input
+ :initarg :input
+ :reader base64-error-input)
+ (position
+ :initarg :position
+ :reader base64-error-position
+ :type unsigned-byte)))
+(define-condition bad-base64-character (base64-error)
+ ((code :initarg :code :reader bad-base64-character-code))
+ (:report (lambda (condition stream)
+ (format stream "Bad character ~S at index ~D of ~S"
+ (code-char (bad-base64-character-code condition))
+ (base64-error-position condition)
+ (base64-error-input condition)))))
-;;; Decoding
+(define-condition incomplete-base64-data (base64-error)
+ ()
+ (:report (lambda (condition stream)
+ (format stream "Unexpected end of Base64 data at index ~D of ~S"
+ (base64-error-position condition)
+ (base64-error-input condition)))))
-#+ignore
-(defmacro def-base64-stream-to-* (output-type)
- `(defun ,(intern (concatenate 'string (symbol-name :base64-stream-to-)
- (symbol-name output-type)))
- (input &key (uri nil)
- ,@(when (eq output-type :stream)
- '(stream)))
- ,(concatenate 'string "Decode base64 stream to " (string-downcase
- (symbol-name output-type)))
- (declare (stream input)
- (optimize (speed 3)))
- (let ((pad (if uri *uri-pad-char* *pad-char*))
- (decode-table (if uri *uri-decode-table* *decode-table*)))
- (declare (type decode-table decode-table)
- (type character pad))
- (let (,@(case output-type
- (:string
- '((result (make-string (* 3 (truncate (length string) 4))))))
- (:usb8-array
- '((result (make-array (* 3 (truncate (length string) 4))
- :element-type '(unsigned-byte 8)
- :fill-pointer nil
- :adjustable nil)))))
- (ridx 0))
- (declare ,@(case output-type
- (:string
- '((simple-string result)))
- (:usb8-array
- '((type (array (usigned-byte 8) (*)) result))))
- (fixnum ridx))
- (do* ((bitstore 0)
- (bitcount 0)
- (char (read-char stream nil #\null)
- (read-char stream nil #\null)))
- ((eq char #\null)
- ,(case output-type
- (:stream
- 'stream)
- ((:string :usb8-array)
- 'result)
- ;; ((:stream :string)
- ;; '(subseq result 0 ridx))))
- ))
- (declare (fixnum bitstore bitcount)
- (character char))
- (let ((svalue (aref decode-table (the fixnum (char-code char)))))
- (declare (fixnum svalue))
- (cond
- ((>= svalue 0)
- (setf bitstore (logior
- (the fixnum (ash bitstore 6))
- svalue))
- (incf bitcount 6)
- (when (>= bitcount 8)
- (decf bitcount 8)
- (let ((ovalue (the fixnum
- (logand
- (the fixnum
- (ash bitstore
- (the fixnum (- bitcount))))
- #xFF))))
- (declare (fixnum ovalue))
- ,(case output-type
- (:string
- '(setf (char result ridx) (code-char ovalue)))
- (:usb8-array
- '(setf (aref result ridx) ovalue))
- (:stream
- '(write-char (code-char ovalue) stream)))
- (incf ridx)
- (setf bitstore (the fixnum (logand bitstore #xFF))))))
- ((char= char pad)
- ;; Could add checks to make sure padding is correct
- ;; Currently, padding is ignored
- )
- ((whitespace-p char)
- ;; Ignore whitespace
- )
- ((minusp svalue)
- (warn "Bad character ~W in base64 decode" char))
- )))))))
+(deftype array-index (&optional (length array-dimension-limit))
+ `(integer 0 (,length)))
-;;(def-base64-stream-to-* :string)
-;;(def-base64-stream-to-* :stream)
-;;(def-base64-stream-to-* :usb8-array)
+(deftype array-length (&optional (length array-dimension-limit))
+ `(integer 0 ,length))
-(defmacro def-base64-string-to-* (output-type)
- `(defun ,(intern (concatenate 'string (symbol-name :base64-string-to-)
- (symbol-name output-type)))
- (input &key (uri nil)
- ,@(when (eq output-type :stream)
- '(stream)))
- ,(concatenate 'string "Decode base64 string to " (string-downcase
- (symbol-name output-type)))
- (declare (string input)
- (optimize (speed 3)))
- (let ((pad (if uri *uri-pad-char* *pad-char*))
- (decode-table (if uri *uri-decode-table* *decode-table*)))
- (declare (type decode-table decode-table)
- (type character pad))
- (let (,@(case output-type
- (:string
- '((result (make-string (* 3 (truncate (length input) 4))))))
- (:usb8-array
- '((result (make-array (* 3 (truncate (length input) 4))
- :element-type '(unsigned-byte 8)
- :fill-pointer nil
- :adjustable nil)))))
- (ridx 0))
- (declare ,@(case output-type
- (:string
- '((simple-string result)))
- (:usb8-array
- '((type (array (unsigned-byte 8) (*)) result))))
- (fixnum ridx))
- (loop
- for char of-type character across input
- for svalue of-type fixnum = (aref decode-table
- (the fixnum (char-code char)))
- with bitstore of-type fixnum = 0
- with bitcount of-type fixnum = 0
- do
- (cond
- ((>= svalue 0)
- (setf bitstore (logior
- (the fixnum (ash bitstore 6))
- svalue))
- (incf bitcount 6)
- (when (>= bitcount 8)
- (decf bitcount 8)
- (let ((ovalue (the fixnum
- (logand
- (the fixnum
- (ash bitstore
- (the fixnum (- bitcount))))
- #xFF))))
- (declare (fixnum ovalue))
- ,(case output-type
- (:string
- '(setf (char result ridx) (code-char ovalue)))
- (:usb8-array
- '(setf (aref result ridx) ovalue))
- (:stream
- '(write-char (code-char ovalue) stream)))
- (incf ridx)
- (setf bitstore (the fixnum (logand bitstore #xFF))))))
- ((char= char pad)
- ;; Could add checks to make sure padding is correct
- ;; Currently, padding is ignored
- )
- ((whitespace-p char)
- ;; Ignore whitespace
- )
- ((minusp svalue)
- (warn "Bad character ~W in base64 decode" char))
- ))
- ,(case output-type
- (:stream
- 'stream)
- ((:usb8-array :string)
- '(subseq result 0 ridx)))))))
+(deftype character-code ()
+ `(integer 0 (,char-code-limit)))
-(def-base64-string-to-* :string)
-(def-base64-string-to-* :stream)
-(def-base64-string-to-* :usb8-array)
+(defmacro etypecase/unroll ((var &rest types) &body body)
+ #+sbcl `(etypecase ,var
+ ,@(loop for type in types
+ collect `(,type ,@body)))
+ #-sbcl `(locally
+ (declare (type (or ,@types) ,var))
+ ,@body))
-;; input-mode can be :string or :stream
-;; input-format can be :character or :usb8
+(defmacro let/typed ((&rest vars) &body body)
+ `(let ,(loop for (var value) in vars
+ collect (list var value))
+ (declare ,@(loop for (var nil type) in vars
+ when type
+ collect (list 'type type var)))
+ ,@body))
+
+(defmacro define-base64-decoder (hose sink)
+ `(defun ,(intern (format nil "~A-~A-~A-~A" '#:base64 hose '#:to sink))
+ (input &key (table +decode-table+)
+ (uri nil)
+ ,@(when (eq sink :stream) `(stream))
+ (whitespace :ignore))
+ ,(format nil "~
+Decode Base64 ~(~A~) to ~(~A~).
+
+TABLE is the decode table to use. Two decode tables are provided:
++DECODE-TABLE+ (used by default) and +URI-DECODE-TABLE+. See
+MAKE-DECODE-TABLE.
-(defun base64-string-to-integer (string &key (uri nil))
- "Decodes a base64 string to an integer"
- (declare (string string)
- (optimize (speed 3)))
- (let ((pad (if uri *uri-pad-char* *pad-char*))
- (decode-table (if uri *uri-decode-table* *decode-table*)))
- (declare (type decode-table decode-table)
- (character pad))
- (let ((value 0))
- (declare (integer value))
- (loop
- for char of-type character across string
- for svalue of-type fixnum =
- (aref decode-table (the fixnum (char-code char)))
- do
- (cond
- ((>= svalue 0)
- (setq value (+ svalue (ash value 6))))
- ((char= char pad)
- (setq value (ash value -2)))
- ((whitespace-p char)
- ; ignore whitespace
- )
- ((minusp svalue)
- (warn "Bad character ~W in base64 decode" char))))
- value)))
+For backwards-compatibility the URI parameter is supported. If it is
+true, then +URI-DECODE-TABLE+ is used, and the value for TABLE
+parameter is ignored.
+WHITESPACE can be one of:
-(defun base64-stream-to-integer (stream &key (uri nil))
- "Decodes a base64 string to an integer"
- (declare (stream stream)
- (optimize (speed 3)))
- (let ((pad (if uri *uri-pad-char* *pad-char*))
- (decode-table (if uri *uri-decode-table* *decode-table*)))
- (declare (type decode-table decode-table)
- (character pad))
- (do* ((value 0)
- (char (read-char stream nil #\null)
- (read-char stream nil #\null)))
- ((eq char #\null)
- value)
- (declare (integer value)
- (character char))
- (let ((svalue (aref decode-table (the fixnum (char-code char)))))
- (declare (fixnum svalue))
- (cond
- ((>= svalue 0)
- (setq value (+ svalue (ash value 6))))
- ((char= char pad)
- (setq value (ash value -2)))
- ((whitespace-p char) ; ignore whitespace
- )
- ((minusp svalue)
- (warn "Bad character ~W in base64 decode" char)))))))
+ :ignore - Whitespace characters are ignored (default).
+ :signal - Signal a BAD-BASE64-CHARACTER condition using SIGNAL.
+ :error - Signal a BAD-BASE64-CHARACTER condition using ERROR."
+ hose sink)
+ (declare (optimize (speed 3) (safety 1))
+ (type decode-table table)
+ (type ,(ecase hose
+ (:stream 'stream)
+ (:string 'string))
+ input))
+ (let/typed ((decode-table (if uri +uri-decode-table+ table)
+ decode-table)
+ ,@(ecase sink
+ (:stream)
+ (:usb8-array
+ (ecase hose
+ (:stream
+ `((result (make-array 1024
+ :element-type '(unsigned-byte 8)
+ :adjustable t
+ :fill-pointer 0)
+ (array (unsigned-byte 8) (*)))))
+ (:string
+ `((result (make-array (* 3 (ceiling (length input) 4))
+ :element-type '(unsigned-byte 8))
+ (simple-array (unsigned-byte 8) (*)))
+ (rpos 0 array-index)))))
+ (:string
+ (case hose
+ (:stream
+ `((result (make-array 1024
+ :element-type 'character
+ :adjustable t
+ :fill-pointer 0)
+ (array character (*)))))
+ (:string
+ `((result (make-array (* 3 (ceiling (length input) 4))
+ :element-type 'character)
+ (simple-array character (*)))
+ (rpos 0 array-index)))))
+ (:integer
+ `((result 0 unsigned-byte)))))
+ (flet ((bad-char (pos code &optional (action :error))
+ (let ((args (list 'bad-base64-character
+ :input input
+ :position pos
+ :code code)))
+ (ecase action
+ (:error
+ (apply #'error args))
+ (:cerror
+ (apply #'cerror "Ignore the error and continue." args))
+ (:signal
+ (apply #'signal args)))))
+ (incomplete-input (pos)
+ (error 'incomplete-base64-data :input input :position pos)))
+ ,(let ((body
+ `(let/typed ((ipos 0 array-index)
+ (bitstore 0 (unsigned-byte 24))
+ (bitcount 0 (integer 0 14))
+ (svalue -1 (signed-byte 8))
+ (padchar 0 (integer 0 3))
+ (code 0 fixnum))
+ (loop
+ ,@(ecase hose
+ (:string
+ `((if (< ipos length)
+ (setq code (char-code (aref input ipos)))
+ (return))))
+ (:stream
+ `((let ((char (read-char input nil nil)))
+ (if char
+ (setq code (char-code char))
+ (return))))))
+ (cond
+ ((or (< 127 code)
+ (= -1 (setq svalue (aref decode-table code))))
+ (bad-char ipos code))
+ ((= -2 svalue)
+ (cond ((<= (incf padchar) 2)
+ (unless (<= 2 bitcount)
+ (bad-char ipos code))
+ (decf bitcount 2))
+ (t
+ (bad-char ipos code))))
+ ((= -3 svalue)
+ (ecase whitespace
+ (:ignore
+ ;; Do nothing.
+ )
+ (:error
+ (bad-char ipos code :error))
+ (:signal
+ (bad-char ipos code :signal))))
+ ((not (zerop padchar))
+ (bad-char ipos code))
+ (t
+ (setf bitstore (logior (the (unsigned-byte 24)
+ (ash bitstore 6))
+ svalue))
+ (incf bitcount 6)
+ (when (>= bitcount 8)
+ (decf bitcount 8)
+ (let ((byte (logand (the (unsigned-byte 24)
+ (ash bitstore (- bitcount)))
+ #xFF)))
+ (declare (type (unsigned-byte 8) byte))
+ ,@(ecase sink
+ (:usb8-array
+ (ecase hose
+ (:string
+ `((setf (aref result rpos) byte)
+ (incf rpos)))
+ (:stream
+ `((vector-push-extend byte result)))))
+ (:string
+ (ecase hose
+ (:string
+ `((setf (schar result rpos)
+ (code-char byte))
+ (incf rpos)))
+ (:stream
+ `((vector-push-extend (code-char byte)
+ result)))))
+ (:integer
+ `((setq result
+ (logior (ash result 8) byte))))
+ (:stream
+ '((write-char (code-char byte) stream)))))
+ (setf bitstore (logand bitstore #xFF)))))
+ (incf ipos))
+ (unless (zerop bitcount)
+ (incomplete-input ipos))
+ ,(ecase sink
+ ((:string :usb8-array)
+ (ecase hose
+ (:string
+ `(if (= rpos (length result))
+ result
+ (subseq result 0 rpos)))
+ (:stream
+ `(copy-seq result))))
+ (:integer
+ 'result)
+ (:stream
+ 'stream)))))
+ (ecase hose
+ (:string
+ `(let ((length (length input)))
+ (declare (type array-length length))
+ (etypecase/unroll (input simple-base-string
+ simple-string
+ string)
+ ,body)))
+ (:stream
+ body)))))))
+
+(define-base64-decoder :string :usb8-array)
+(define-base64-decoder :string :string)
+(define-base64-decoder :string :integer)
+(define-base64-decoder :string :stream)
+
+(define-base64-decoder :stream :usb8-array)
+(define-base64-decoder :stream :string)
+(define-base64-decoder :stream :integer)
+(define-base64-decoder :stream :stream)
+
+;; input-mode can be :string or :stream
+;; input-format can be :character or :usb8
projects / cl-base64.git / blobdiff