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#|
This file is a part of zippy
(c) 2020 Shirakumo http://tymoon.eu (shinmera@tymoon.eu)
Author: Nicolas Hafner <shinmera@tymoon.eu>
|#
(in-package #:org.shirakumo.zippy)
(defun entry-flags (entry)
(bitfield (encryption-method entry)
NIL
NIL
T ;; FIXME: Should only set this to T if the /output/ is non-seekable
NIL
NIL
(and (encryption-method entry)
(not (eql :pkware (encryption-method entry))))
NIL NIL NIL NIL T NIL NIL NIL NIL))
(defun backfill-from-content (entry)
(let ((content (content entry)))
(etypecase content
((or string pathname file-stream)
(setf (last-modified entry) (file-write-date content))
(unless (file-name entry)
(setf (file-name entry) (file-namestring content)))
(unless (attributes entry)
(setf (attributes entry) (list `(,(if (pathname-utils:directory-p content)
:directory
:normal)
T)
*compatibility*
(file-attributes:attributes content))))
(unless (pathname-utils:directory-p content)
(typecase content
(file-stream (setf (uncompressed-size entry) (file-length content)))
(T
(with-open-file (stream content :direction :input :element-type '(unsigned-byte 8))
(setf (uncompressed-size entry) (file-length stream)))))))
(stream)
(vector-input
(setf (uncompressed-size entry) (size content)))
(vector
(setf (uncompressed-size entry) (length content)))
(null
(unless (attributes entry) ;; Assume directory.
(setf (attributes entry) (list '(:directory T) *compatibility* (default-attributes-for *compatibility*))))))
(unless (attributes entry)
(setf (attributes entry) (list '(:normal T) *compatibility* (default-attributes-for *compatibility*))))
(when (and content
(null (compression-method entry)))
(if (< 1024 (or (uncompressed-size entry) 1025))
(setf (compression-method entry) :deflate)
(setf (compression-method entry) :store)))))
(defun entry-version (entry)
(encode-version (or (version entry) *version*)
(if (consp (attributes entry))
(second (attributes entry))
*compatibility*)))
(defun entry-compression-id (entry)
(compression-method-id
(if (and (consp (encryption-method entry))
(find (first (encryption-method entry)) '(:ae-1 :ae-2)))
:ae-x
(or (compression-method entry)
:store))))
(defun add-extra-entry (extra entry)
(let ((end (length extra)))
(setf extra (adjust-array extra (+ end (size entry))))
(encode-structure entry extra end)
extra))
(defun entry-to-lf (entry)
(let ((file-name (babel:string-to-octets (file-name entry) :encoding :utf-8))
(extra (make-array 0 :adjustable T :element-type '(unsigned-byte 8))))
(when (and (size entry) (<= #xFFFFFFFF (size entry)))
(add-extra-entry extra (make-zip64-extended-information
28 (size entry) (uncompressed-size entry)
(offset entry) 0)))
(destructuring-bind (&optional method bittage) (enlist (encryption-method entry))
(case method
(:ae-1
(add-extra-entry extra (make-aes-extra-data
7 17729 1
(ecase bittage
(128 1)
(192 2)
(256 3))
(compression-method-id (compression-method entry)))))
(:ae-2
(add-extra-entry extra (make-aes-extra-data
7 17729 2
(ecase bittage
(128 1)
(192 2)
(256 3))
(compression-method-id (compression-method entry)))))
((:pkware NIL))
(T
(add-extra-entry extra (make-encryption-header
8 2 (encryption-method-id method)
bittage 1 #())))))
(multiple-value-bind (date time) (encode-msdos-timestamp (last-modified entry))
(make-local-file (entry-version entry)
(entry-flags entry)
(entry-compression-id entry)
time date (or (crc-32 entry) 0)
(if (size entry) (cap (size entry) 32) 0)
(if (uncompressed-size entry) (cap (uncompressed-size entry) 32) 0)
(length file-name) (length extra) file-name extra))))
(defun entry-to-dd (entry)
(if (< (uncompressed-size entry) #xFFFFFFFF)
(make-data-descriptor (crc-32 entry) (size entry) (uncompressed-size entry))
(make-data-descriptor/64 (crc-32 entry) (size entry) (uncompressed-size entry))))
(defun entry-to-cd (entry)
(let ((file-name (babel:string-to-octets (file-name entry) :encoding :utf-8))
(comment (encode-string (comment entry)))
(extra (make-array 0 :adjustable T :element-type '(unsigned-byte 8))))
(when (or (<= #xFFFFFFFF (size entry))
(<= #xFFFFFFFF (offset entry)))
(add-extra-entry extra (make-zip64-extended-information
28 (size entry) (uncompressed-size entry)
(offset entry) 0)))
(multiple-value-bind (date time) (encode-msdos-timestamp (last-modified entry))
(make-central-directory-entry
(entry-version entry)
(entry-version entry)
(entry-flags entry)
(entry-compression-id entry)
time date (or (crc-32 entry) 0)
(if (size entry) (cap (size entry) 32) 0)
(if (uncompressed-size entry) (cap (uncompressed-size entry) 32) 0)
(length file-name) (length extra) (length comment)
0 0 (or (encode-file-attribute (attributes entry)) 0) (cap (offset entry) 32)
file-name extra comment))))
(defun encode-entry-payload (entry output password)
(cond ((content entry)
(with-io (input (content entry))
(let ((read 0)
(written 0)
(crc #xFFFFFFFF)
(encryption-state (make-encryption-state (encryption-method entry) password))
(compression-state (make-compression-state (compression-method entry))))
(labels ((write-out (buffer start end)
(incf written (- end start))
(output output buffer start end))
(encrypt (buffer start end)
(call-with-encrypted-buffer #'write-out buffer start end encryption-state))
(compress (buffer start end)
(incf read (- end start))
(loop for i from start below end
do (setf crc (crc32-rotate crc (aref buffer i))))
(call-with-compressed-buffer #'encrypt buffer start end compression-state)))
(etypecase input
(stream
(when (or (not (typep input 'file-stream))
(not (pathname-utils:directory-p input)))
(loop with buffer = (make-array 4096 :element-type '(unsigned-byte 8))
for read = (read-sequence buffer input)
while (< 0 read)
do (compress buffer 0 read))))
(vector-input
(compress (vector-input-vector input) (vector-input-index input) (vector-input-end input)))
(directory-input))
(call-with-completed-compressed-buffer #'encrypt compression-state)
(call-with-completed-encrypted-buffer #'write-out encryption-state))
(setf (crc-32 entry) (logxor #xFFFFFFFF crc))
(setf (size entry) written)
(setf (uncompressed-size entry) read))))
((and (offset entry) (size entry))
;; We are copying from source archive. Just transfer the bytes.
(labels ((write-out (buffer start end)
(output output buffer start end)))
(entry-raw-bytes #'write-out entry)))
(T
(setf (crc-32 entry) #xFFFFFFFF)
(setf (size entry) 0)
(setf (uncompressed-size entry) 0))))
(defun encode-file (zip-file output &key password)
(loop for i from 0
for entry across (entries zip-file)
do (setf (offset entry) (index output))
(backfill-from-content entry)
(write-structure* (entry-to-lf entry) output)
;; TODO: Decryption header and all that guff
(encode-entry-payload entry output password)
(write-structure* (entry-to-dd entry) output)
;; FIXME: If writing to a file-stream or vector, backtrack and
;; Fixup the LF entry with size/crc/flag
)
(let ((cd-start (index output)))
(loop for entry across (entries zip-file)
do (write-structure* (entry-to-cd entry) output))
(let ((cd-end (index output))
(comment (encode-string (comment zip-file))))
(write-structure* (make-end-of-central-directory/64
44
(encode-version *version*)
;; FIXME: be smarter about noting the min version.
(encode-version *version*)
0 0 (length (entries zip-file)) (length (entries zip-file))
(- cd-end cd-start) cd-start #())
output)
(write-structure* (make-end-of-central-directory-locator/64
0 cd-end 1)
output)
(write-structure* (make-end-of-central-directory
0 0
(cap (length (entries zip-file)) 16)
(cap (length (entries zip-file)) 16)
(cap (- cd-end cd-start) 32)
(cap cd-start 32)
(length comment) comment)
output))))
|
