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-rw-r--r--Makefile.am1
-rw-r--r--chickadee/base64.scm312
-rw-r--r--tests/base64.scm32
3 files changed, 92 insertions, 253 deletions
diff --git a/Makefile.am b/Makefile.am
index fe56434..4b3593d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -102,6 +102,7 @@ SOURCES = \
chickadee/cli/bundle.scm
TESTS = \
+ tests/base64.scm \
tests/vector.scm \
tests/rect.scm \
tests/matrix.scm \
diff --git a/chickadee/base64.scm b/chickadee/base64.scm
index 5b6455a..74fd0c5 100644
--- a/chickadee/base64.scm
+++ b/chickadee/base64.scm
@@ -1,259 +1,65 @@
-;; -*- mode: scheme; coding: utf-8 -*-
-;;
-;; This module was renamed from (weinholt text base64 (1 0 20100612)) to
-;; (guix base64) by Nikita Karetnikov <nikita@karetnikov.org> on
-;; February 12, 2014.
-;;
-;; Some optimizations made by Ludovic Courtès <ludo@gnu.org>, 2015.
-;; Turned into a Guile module (instead of R6RS).
-;;
-;; This program is free software: you can redistribute it and/or modify
-;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation, either version 3 of the License, or
-;; (at your option) any later version.
-;;
-;; This program is distributed in the hope that it will be useful,
-;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-;; GNU General Public License for more details.
-;;
-;; You should have received a copy of the GNU General Public License
-;; along with this program. If not, see <http://www.gnu.org/licenses/>.
-;;
-;; This file incorporates work covered by the following copyright and
-;; permission notice:
-;;
-;; Copyright © 2009, 2010 Göran Weinholt <goran@weinholt.se>
-;;
-;; Permission is hereby granted, free of charge, to any person obtaining a
-;; copy of this software and associated documentation files (the "Software"),
-;; to deal in the Software without restriction, including without limitation
-;; the rights to use, copy, modify, merge, publish, distribute, sublicense,
-;; and/or sell copies of the Software, and to permit persons to whom the
-;; Software is furnished to do so, subject to the following conditions:
-;;
-;; The above copyright notice and this permission notice shall be included in
-;; all copies or substantial portions of the Software.
-;;
-;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-;; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-;; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
-;; THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-;; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-;; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-;; DEALINGS IN THE SOFTWARE.
-
-;; RFC 4648 Base-N Encodings
+;;; Chickadee Game Toolkit
+;;; Copyright © 2023 David Thompson <dthompson2@worcester.edu>
+;;;
+;;; Licensed under the Apache License, Version 2.0 (the "License");
+;;; you may not use this file except in compliance with the License.
+;;; You may obtain a copy of the License at
+;;;
+;;; http://www.apache.org/licenses/LICENSE-2.0
+;;;
+;;; Unless required by applicable law or agreed to in writing, software
+;;; distributed under the License is distributed on an "AS IS" BASIS,
+;;; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+;;; See the License for the specific language governing permissions and
+;;; limitations under the License.
(define-module (chickadee base64)
- #:export (base64-encode
- base64-decode
- base64-alphabet
- base64url-alphabet
- get-delimited-base64
- put-delimited-base64)
- #:use-module (srfi srfi-11)
- #:use-module (srfi srfi-60)
#:use-module (rnrs bytevectors)
- #:use-module (rnrs io ports))
-
-
-(define-syntax define-alias
- (syntax-rules ()
- ((_ new old)
- (define-syntax new (identifier-syntax old)))))
-
-;; Force the use of Guile's own primitives to avoid the overhead of its 'fx'
-;; procedures.
+ #:export (base64-decode))
-(define-alias fxbit-field bit-field)
-(define-alias fxarithmetic-shift ash)
-(define-alias fxarithmetic-shift-left ash)
-(define-alias fxand logand)
-(define-alias fxior logior)
-(define-alias fxxor logxor)
-(define-alias fx=? =)
-(define-alias fx+ +)
-(define-alias mod modulo)
-
-(define-syntax-rule (assert exp)
- (unless exp
- (throw 'assertion-failure 'exp)))
-
-(define base64-alphabet
+(define %base64-chars
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/")
-(define base64url-alphabet
- "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_")
-
-(define base64-encode
- (case-lambda
- ;; Simple interface. Returns a string containing the canonical
- ;; base64 representation of the given bytevector.
- ((bv)
- (base64-encode bv 0 (bytevector-length bv) #f #f base64-alphabet #f))
- ((bv start)
- (base64-encode bv start (bytevector-length bv) #f #f base64-alphabet #f))
- ((bv start end)
- (base64-encode bv start end #f #f base64-alphabet #f))
- ((bv start end line-length)
- (base64-encode bv start end line-length #f base64-alphabet #f))
- ((bv start end line-length no-padding)
- (base64-encode bv start end line-length no-padding base64-alphabet #f))
- ((bv start end line-length no-padding alphabet)
- (base64-encode bv start end line-length no-padding alphabet #f))
- ;; Base64 encodes the bytes [start,end[ in the given bytevector.
- ;; Lines are limited to line-length characters (unless #f),
- ;; which must be a multiple of four. To omit the padding
- ;; characters (#\=) set no-padding to a true value. If port is
- ;; #f, returns a string.
- ((bv start end line-length no-padding alphabet port)
- (assert (or (not line-length) (zero? (mod line-length 4))))
- (let-values (((p extract) (if port
- (values port (lambda () (values)))
- (open-string-output-port))))
- (letrec ((put (if line-length
- (let ((chars 0))
- (lambda (p c)
- (when (fx=? chars line-length)
- (set! chars 0)
- (put-char p #\linefeed))
- (set! chars (fx+ chars 1))
- (put-char p c)))
- put-char)))
- (let lp ((i start))
- (cond ((= i end))
- ((<= (+ i 3) end)
- (let ((x (bytevector-uint-ref bv i (endianness big) 3)))
- (put p (string-ref alphabet (fxbit-field x 18 24)))
- (put p (string-ref alphabet (fxbit-field x 12 18)))
- (put p (string-ref alphabet (fxbit-field x 6 12)))
- (put p (string-ref alphabet (fxbit-field x 0 6)))
- (lp (+ i 3))))
- ((<= (+ i 2) end)
- (let ((x (fxarithmetic-shift-left (bytevector-u16-ref bv i (endianness big)) 8)))
- (put p (string-ref alphabet (fxbit-field x 18 24)))
- (put p (string-ref alphabet (fxbit-field x 12 18)))
- (put p (string-ref alphabet (fxbit-field x 6 12)))
- (unless no-padding
- (put p #\=))))
- (else
- (let ((x (fxarithmetic-shift-left (bytevector-u8-ref bv i) 16)))
- (put p (string-ref alphabet (fxbit-field x 18 24)))
- (put p (string-ref alphabet (fxbit-field x 12 18)))
- (unless no-padding
- (put p #\=)
- (put p #\=)))))))
- (extract)))))
-
- ;; Decodes a base64 string. The string must contain only pure
- ;; unpadded base64 data.
-
-(define base64-decode
- (case-lambda
- ((str)
- (base64-decode str base64-alphabet #f))
- ((str alphabet)
- (base64-decode str alphabet #f))
- ((str alphabet port)
- (unless (zero? (mod (string-length str) 4))
- (error 'base64-decode
- "input string must be a multiple of four characters"))
- (let-values (((p extract) (if port
- (values port (lambda () (values)))
- (open-bytevector-output-port))))
- (do ((i 0 (+ i 4)))
- ((= i (string-length str))
- (extract))
- (let ((c1 (string-ref str i))
- (c2 (string-ref str (+ i 1)))
- (c3 (string-ref str (+ i 2)))
- (c4 (string-ref str (+ i 3))))
- ;; TODO: be more clever than string-index
- (let ((i1 (string-index alphabet c1))
- (i2 (string-index alphabet c2))
- (i3 (string-index alphabet c3))
- (i4 (string-index alphabet c4)))
- (cond ((and i1 i2 i3 i4)
- (let ((x (fxior (fxarithmetic-shift-left i1 18)
- (fxarithmetic-shift-left i2 12)
- (fxarithmetic-shift-left i3 6)
- i4)))
- (put-u8 p (fxbit-field x 16 24))
- (put-u8 p (fxbit-field x 8 16))
- (put-u8 p (fxbit-field x 0 8))))
- ((and i1 i2 i3 (char=? c4 #\=)
- (= i (- (string-length str) 4)))
- (let ((x (fxior (fxarithmetic-shift-left i1 18)
- (fxarithmetic-shift-left i2 12)
- (fxarithmetic-shift-left i3 6))))
- (put-u8 p (fxbit-field x 16 24))
- (put-u8 p (fxbit-field x 8 16))))
- ((and i1 i2 (char=? c3 #\=) (char=? c4 #\=)
- (= i (- (string-length str) 4)))
- (let ((x (fxior (fxarithmetic-shift-left i1 18)
- (fxarithmetic-shift-left i2 12))))
- (put-u8 p (fxbit-field x 16 24))))
- (else
- (error 'base64-decode "invalid input"
- (list c1 c2 c3 c4)))))))))))
-
-(define (get-line-comp f port)
- (if (port-eof? port)
- (eof-object)
- (f (get-line port))))
-
- ;; Reads the common -----BEGIN/END type----- delimited format from
- ;; the given port. Returns two values: a string with the type and a
- ;; bytevector containing the base64 decoded data. The second value
- ;; is the eof object if there is an eof before the BEGIN delimiter.
-
-(define (get-delimited-base64 port)
- (define (get-first-data-line port)
- ;; Some MIME data has header fields in the same format as mail
- ;; or http. These are ignored.
- (let ((line (get-line-comp string-trim-both port)))
- (cond ((eof-object? line) line)
- ((string-index line #\:)
- (let lp () ;read until empty line
- (let ((line (get-line-comp string-trim-both port)))
- (if (string=? line "")
- (get-line-comp string-trim-both port)
- (lp)))))
- (else line))))
- (let ((line (get-line-comp string-trim-both port)))
- (cond ((eof-object? line)
- (values "" (eof-object)))
- ((string=? line "")
- (get-delimited-base64 port))
- ((and (string-prefix? "-----BEGIN " line)
- (string-suffix? "-----" line))
- (let* ((type (substring line 11 (- (string-length line) 5)))
- (endline (string-append "-----END " type "-----")))
- (let-values (((outp extract) (open-bytevector-output-port)))
- (let lp ((line (get-first-data-line port)))
- (cond ((eof-object? line)
- (error 'get-delimited-base64
- "unexpected end of file"))
- ((string-prefix? "-" line)
- (unless (string=? line endline)
- (error 'get-delimited-base64
- "bad end delimiter" type line))
- (values type (extract)))
- (else
- (unless (and (= (string-length line) 5)
- (string-prefix? "=" line)) ;Skip Radix-64 checksum
- (base64-decode line base64-alphabet outp))
- (lp (get-line-comp string-trim-both port))))))))
- (else ;skip garbage (like in openssl x509 -in foo -text output).
- (get-delimited-base64 port)))))
-
-(define put-delimited-base64
- (case-lambda
- ((port type bv line-length)
- (display (string-append "-----BEGIN " type "-----\n") port)
- (base64-encode bv 0 (bytevector-length bv)
- line-length #f base64-alphabet port)
- (display (string-append "\n-----END " type "-----\n") port))
- ((port type bv)
- (put-delimited-base64 port type bv 76))))
+(define %decode-table
+ (let ((table (make-hash-table)))
+ (let loop ((i 0))
+ (when (< i 64)
+ (hashv-set! table (string-ref %base64-chars i) i)
+ (loop (+ i 1))))
+ (hashv-set! table #\= 0)
+ table))
+
+(define (base64-decode str)
+ "Decode the base64 encoded string STR and return a bytevector
+containing the decoded data."
+ (let* ((n (string-length str))
+ (groups (/ n 4)))
+ (define (padding? i)
+ (eqv? (string-ref str i) #\=))
+ (define (decode i)
+ (let ((c (string-ref str i)))
+ (or (hashv-ref %decode-table c)
+ (error 'base64-error "invalid base64 character" c))))
+ (define (decode4 group)
+ (let ((start (* group 4)))
+ (logior (ash (decode start) 18)
+ (ash (decode (+ start 1)) 12)
+ (ash (decode (+ start 2)) 6)
+ (decode (+ start 3)))))
+ (unless (exact-integer? groups)
+ (error 'base64-error "invalid character count"))
+ (let* ((padding (cond
+ ((and (padding? (- n 2)) (padding? (- n 1))) 2)
+ ((padding? (- n 1)) 1)
+ (else 0)))
+ (bv (make-bytevector (- (* groups 3) padding))))
+ (let loop ((i 0))
+ (cond
+ ((= i (- groups 1))
+ (let ((x (ash (decode4 i) (* padding -8))))
+ (bytevector-sint-set! bv (* i 3) x (endianness big) (- 3 padding))
+ bv))
+ ((< i groups)
+ (bytevector-sint-set! bv (* i 3) (decode4 i) (endianness big) 3)
+ (loop (+ i 1)))))
+ bv)))
diff --git a/tests/base64.scm b/tests/base64.scm
new file mode 100644
index 0000000..dba4f3b
--- /dev/null
+++ b/tests/base64.scm
@@ -0,0 +1,32 @@
+;;; Chickadee Game Toolkit
+;;; Copyright © 2023 David Thompson <dthompson2@worcester.edu>
+;;;
+;;; Licensed under the Apache License, Version 2.0 (the "License");
+;;; you may not use this file except in compliance with the License.
+;;; You may obtain a copy of the License at
+;;;
+;;; http://www.apache.org/licenses/LICENSE-2.0
+;;;
+;;; Unless required by applicable law or agreed to in writing, software
+;;; distributed under the License is distributed on an "AS IS" BASIS,
+;;; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+;;; See the License for the specific language governing permissions and
+;;; limitations under the License.
+
+(define-module (tests base64)
+ #:use-module (chickadee base64)
+ #:use-module (rnrs bytevectors)
+ #:use-module (srfi srfi-64)
+ #:use-module (tests utils))
+
+(with-tests "base64"
+ (test-group "base64-decode"
+ (test-equal "encoded text no padding"
+ "hello!"
+ (utf8->string (base64-decode "aGVsbG8h")))
+ (test-equal "encoded text with one byte of padding"
+ "hello"
+ (utf8->string (base64-decode "aGVsbG8=")))
+ (test-equal "encoded text with two bytes of padding"
+ "what's up?"
+ (utf8->string (base64-decode "d2hhdCdzIHVwPw==")))))