%    Copyright (C) 1992, 1993 Aladdin Enterprises.  All rights reserved.% % This file is part of AFPL Ghostscript.% % AFPL Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author or% distributor accepts any responsibility for the consequences of using it, or% for whether it serves any particular purpose or works at all, unless he or% she says so in writing.  Refer to the Aladdin Free Public License (the% "License") for full details.% % Every copy of AFPL Ghostscript must include a copy of the License, normally% in a plain ASCII text file named PUBLIC.  The License grants you the right% to copy, modify and redistribute AFPL Ghostscript, but only under certain% conditions described in the License.  Among other things, the License% requires that the copyright notice and this notice be preserved on all% copies. % $Id: type1enc.ps,v 1.2 2000/09/19 18:29:11 lpd Exp $% 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