Edit File: type1enc.ps
% Copyright (C) 1992, 1993 Aladdin Enterprises. All rights reserved. % % This software is provided AS-IS with no warranty, either express or % implied. % % This software is distributed under license and may not be copied, % modified or distributed except as expressly authorized under the terms % of the license contained in the file LICENSE in this distribution. % % For more information about licensing, please refer to % http://www.ghostscript.com/licensing/. For information on % commercial licensing, go to http://www.artifex.com/licensing/ or % contact Artifex Software, Inc., 101 Lucas Valley Road #110, % San Rafael, CA 94903, U.S.A., +1(415)492-9861. % $Id: type1enc.ps 6300 2005-12-28 19:56:24Z giles $ % type1enc.ps % PostScript language versions of the Type 1 encryption/decryption algorithms. % This file is normally not needed with Ghostscript, since Ghostscript % implements these algorithms in C. For the specifications, see Chapter 7 of % "Adobe Type 1 Font Format," ISBN 0-201-57044-0, published by Addison-Wesley. /.type1crypt % <R> <from> <to> <proc> .type1crypt <R'> <to> % (auxiliary procedure) { 4 1 roll 0 2 index length getinterval 0 1 2 index length 1 sub { % Stack: proc R from to index 2 index 1 index get % proc R from to index C/P 4 index -8 bitshift xor 3 copy put % proc R from to index P/C 5 index exec % proc R from to C % Compute R' = ((R + C) * 52845 + 22719) mod 65536 % without exceeding a 31-bit integer magnitude, given that % 0 <= R <= 65535 and 0 <= C <= 255. 4 -1 roll add dup 20077 mul % 52845 - 32768 exch 1 and 15 bitshift add % only care about 16 low-order bits 22719 add 65535 and 3 1 roll } for exch pop 3 -1 roll pop } bind def % <state> <fromString> <toString> .type1encrypt <newState> <toSubstring> % Encrypts fromString according to the algorithm for Adobe % Type 1 fonts, writing the result into toString. % toString must be at least as long as fromString or a % rangecheck error occurs. state is the initial state of % the encryption algorithm (a 16-bit non-negative % integer); newState is the new state of the algorithm. /.type1encrypt { { exch pop } .type1crypt } bind def % <state> <fromString> <toString> .type1decrypt <newState> <toSubstring> % Decrypts fromString according to the algorithm for Adobe % Type 1 fonts, writing the result into toString. Other % specifications are as for type1encrypt. /.type1decrypt { { pop 2 index exch get } .type1crypt } bind def
Back to File Manager