Edit
kc3-lang/freetype/src/cid/cidparse.c
Werner Lemberg
- src/cid/cidparse.c
-
/**************************************************************************** * * cidparse.c * * CID-keyed Type1 parser (body). * * Copyright (C) 1996-2025 by * David Turner, Robert Wilhelm, and Werner Lemberg. * * This file is part of the FreeType project, and may only be used, * modified, and distributed under the terms of the FreeType project * license, LICENSE.TXT. By continuing to use, modify, or distribute * this file you indicate that you have read the license and * understand and accept it fully. * */ #include <freetype/internal/ftdebug.h> #include <freetype/internal/ftobjs.h> #include <freetype/internal/ftstream.h> #include "cidparse.h" #include "ciderrs.h" /************************************************************************** * * The macro FT_COMPONENT is used in trace mode. It is an implicit * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log * messages during execution. */ #undef FT_COMPONENT #define FT_COMPONENT cidparse /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** INPUT STREAM PARSER *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ #define STARTDATA "StartData" #define STARTDATA_LEN ( sizeof ( STARTDATA ) - 1 ) #define SFNTS "/sfnts" #define SFNTS_LEN ( sizeof ( SFNTS ) - 1 ) FT_LOCAL_DEF( FT_Error ) cid_parser_new( CID_Parser* parser, FT_Stream stream, FT_Memory memory, PSAux_Service psaux ) { FT_Error error; FT_ULong base_offset, offset, ps_len; FT_Byte *cur, *limit; FT_Byte *arg1, *arg2; FT_ZERO( parser ); psaux->ps_parser_funcs->init( &parser->root, 0, 0, memory ); parser->stream = stream; base_offset = FT_STREAM_POS(); /* first of all, check the font format in the header */ if ( FT_FRAME_ENTER( 31 ) ) { FT_TRACE2(( " not a CID-keyed font\n" )); error = FT_THROW( Unknown_File_Format ); goto Exit; } if ( ft_strncmp( (char *)stream->cursor, "%!PS-Adobe-3.0 Resource-CIDFont", 31 ) ) { FT_TRACE2(( " not a CID-keyed font\n" )); error = FT_THROW( Unknown_File_Format ); } FT_FRAME_EXIT(); if ( error ) goto Exit; if ( !stream->read ) { /* just parse memory-based streams */ offset = stream->size; } else { /* Find the last `StartData` or `/sfnts`. The parser requires */ /* contiguous memory; attempt to pin as little as necessary. */ /* * The algorithm is as follows (omitting the case with less than 256 * bytes to fill for simplicity). * * 1. Fill the buffer with 256 + STARTDATA_LEN bytes. * * 2. Search for the STARTDATA and SFNTS strings at positions * buffer[0], buffer[1], ..., * buffer[255 + STARTDATA_LEN - SFNTS_LEN]. * * 3. Move the last STARTDATA_LEN bytes to buffer[0]. * * 4. Fill the buffer with 256 bytes, starting at STARTDATA_LEN. * * 5. Repeat with step 2. * */ FT_Byte buffer[256 + STARTDATA_LEN + 1]; /* values for the first loop */ FT_ULong read_len = 256 + STARTDATA_LEN; FT_ULong read_offset = 0; FT_Byte* p = buffer; offset = 0; while ( 1 ) { FT_ULong stream_len; stream_len = stream->size - FT_STREAM_POS(); read_len = FT_MIN( read_len, stream_len ); if ( read_len && FT_STREAM_READ( p, read_len ) ) goto Exit; /* ensure that we do not compare with data beyond the buffer */ p[read_len] = '\0'; limit = p + read_len - SFNTS_LEN; for ( p = buffer; p < limit; p++ ) { if ( p[0] == 'S' && ft_strncmp( (char*)p, STARTDATA, STARTDATA_LEN ) == 0 ) { /* save offset of binary data after `StartData' */ offset = FT_STREAM_POS() - read_len - read_offset + (FT_ULong)( p - buffer ) + STARTDATA_LEN + 1; } else if ( p[1] == 's' && ft_strncmp( (char*)p, SFNTS, SFNTS_LEN ) == 0 ) { offset = FT_STREAM_POS() - read_len - read_offset + (FT_ULong)( p - buffer ) + SFNTS_LEN + 1; } } if ( read_offset + read_len <= STARTDATA_LEN ) { if ( offset ) goto Found; FT_TRACE2(( "cid_parser_new: no `StartData` keyword found\n" )); error = FT_THROW( Invalid_File_Format ); goto Exit; } FT_MEM_MOVE( buffer, buffer + read_offset + read_len - STARTDATA_LEN, STARTDATA_LEN ); /* values for the next loop */ read_len = 256; read_offset = STARTDATA_LEN; p = buffer + read_offset; } } Found: /* We have found an efficient range to look for the binary data or */ /* `/sfnts' token. Now rewind and extract the frame corresponding to */ /* this PostScript section. */ ps_len = offset - base_offset; if ( FT_STREAM_SEEK( base_offset ) || FT_FRAME_EXTRACT( ps_len, parser->postscript ) ) goto Exit; parser->data_offset = offset; parser->postscript_len = ps_len; parser->root.base = parser->postscript; parser->root.cursor = parser->postscript; parser->root.limit = parser->root.cursor + ps_len; parser->num_dict = FT_UINT_MAX; /* Find the first real `StartData' or `/sfnts' -- the last one */ /* could be in a comment or string. We also get the arguments */ /* of `StartData' to find out whether the data is represented in */ /* binary or hex format. */ arg1 = parser->root.cursor; cid_parser_skip_PS_token( parser ); cid_parser_skip_spaces ( parser ); arg2 = parser->root.cursor; cid_parser_skip_PS_token( parser ); cid_parser_skip_spaces ( parser ); limit = parser->root.limit; cur = parser->root.cursor; while ( cur <= limit - SFNTS_LEN ) { if ( parser->root.error ) { error = parser->root.error; goto Exit; } if ( cur[0] == 'S' && cur <= limit - STARTDATA_LEN && ft_strncmp( (char*)cur, STARTDATA, STARTDATA_LEN ) == 0 ) { T1_TokenRec type_token; FT_Long binary_length; FT_ULong found_offset; parser->root.cursor = arg1; cid_parser_to_token( parser, &type_token ); if ( type_token.limit - type_token.start == 5 && ft_memcmp( (char*)type_token.start, "(Hex)", 5 ) == 0 ) { parser->root.cursor = arg2; binary_length = cid_parser_to_int( parser ); if ( binary_length < 0 ) { FT_ERROR(( "cid_parser_new: invalid length of hex data\n" )); error = FT_THROW( Invalid_File_Format ); } else parser->binary_length = (FT_ULong)binary_length; } /* set the real values for the parser, if different */ found_offset = (FT_ULong)( cur - parser->postscript ) + STARTDATA_LEN + 1; if ( found_offset != offset ) { FT_FRAME_RELEASE( parser->postscript ); ps_len = found_offset - base_offset; if ( FT_STREAM_SEEK( base_offset ) || FT_FRAME_EXTRACT( ps_len, parser->postscript ) ) goto Exit; parser->data_offset = found_offset; parser->postscript_len = ps_len; parser->root.base = parser->postscript; parser->root.cursor = parser->postscript; parser->root.limit = parser->root.cursor + ps_len; } goto Exit; } else if ( cur[1] == 's' && ft_strncmp( (char*)cur, SFNTS, SFNTS_LEN ) == 0 ) { FT_TRACE2(( "cid_parser_new: cannot handle Type 11 fonts\n" )); error = FT_THROW( Unknown_File_Format ); goto Exit; } cid_parser_skip_PS_token( parser ); cid_parser_skip_spaces ( parser ); arg1 = arg2; arg2 = cur; cur = parser->root.cursor; } FT_TRACE2(( "cid_parser_new: no `StartData` token found\n" )); error = FT_THROW( Invalid_File_Format ); Exit: return error; } #undef STARTDATA #undef STARTDATA_LEN #undef SFNTS #undef SFNTS_LEN FT_LOCAL_DEF( void ) cid_parser_done( CID_Parser* parser ) { /* always free the private dictionary */ if ( parser->postscript ) { FT_Stream stream = parser->stream; FT_FRAME_RELEASE( parser->postscript ); } parser->root.funcs.done( &parser->root ); } /* END */