1 /**************************************************************************** 2 * 3 * cidparse.c 4 * 5 * CID-keyed Type1 parser (body). 6 * 7 * Copyright (C) 1996-2023 by 8 * David Turner, Robert Wilhelm, and Werner Lemberg. 9 * 10 * This file is part of the FreeType project, and may only be used, 11 * modified, and distributed under the terms of the FreeType project 12 * license, LICENSE.TXT. By continuing to use, modify, or distribute 13 * this file you indicate that you have read the license and 14 * understand and accept it fully. 15 * 16 */ 17 18 19 #include <freetype/internal/ftdebug.h> 20 #include <freetype/internal/ftobjs.h> 21 #include <freetype/internal/ftstream.h> 22 23 #include "cidparse.h" 24 25 #include "ciderrs.h" 26 27 28 /************************************************************************** 29 * 30 * The macro FT_COMPONENT is used in trace mode. It is an implicit 31 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log 32 * messages during execution. 33 */ 34 #undef FT_COMPONENT 35 #define FT_COMPONENT cidparse 36 37 38 /*************************************************************************/ 39 /*************************************************************************/ 40 /*************************************************************************/ 41 /***** *****/ 42 /***** INPUT STREAM PARSER *****/ 43 /***** *****/ 44 /*************************************************************************/ 45 /*************************************************************************/ 46 /*************************************************************************/ 47 48 49 #define STARTDATA "StartData" 50 #define STARTDATA_LEN ( sizeof ( STARTDATA ) - 1 ) 51 #define SFNTS "/sfnts" 52 #define SFNTS_LEN ( sizeof ( SFNTS ) - 1 ) 53 54 55 FT_LOCAL_DEF( FT_Error ) cid_parser_new(CID_Parser * parser,FT_Stream stream,FT_Memory memory,PSAux_Service psaux)56 cid_parser_new( CID_Parser* parser, 57 FT_Stream stream, 58 FT_Memory memory, 59 PSAux_Service psaux ) 60 { 61 FT_Error error; 62 FT_ULong base_offset, offset, ps_len; 63 FT_Byte *cur, *limit; 64 FT_Byte *arg1, *arg2; 65 66 67 FT_ZERO( parser ); 68 psaux->ps_parser_funcs->init( &parser->root, 0, 0, memory ); 69 70 parser->stream = stream; 71 72 base_offset = FT_STREAM_POS(); 73 74 /* first of all, check the font format in the header */ 75 if ( FT_FRAME_ENTER( 31 ) ) 76 { 77 FT_TRACE2(( " not a CID-keyed font\n" )); 78 error = FT_THROW( Unknown_File_Format ); 79 goto Exit; 80 } 81 82 if ( ft_strncmp( (char *)stream->cursor, 83 "%!PS-Adobe-3.0 Resource-CIDFont", 31 ) ) 84 { 85 FT_TRACE2(( " not a CID-keyed font\n" )); 86 error = FT_THROW( Unknown_File_Format ); 87 } 88 89 FT_FRAME_EXIT(); 90 if ( error ) 91 goto Exit; 92 93 Again: 94 /* now, read the rest of the file until we find */ 95 /* `StartData' or `/sfnts' */ 96 { 97 /* 98 * The algorithm is as follows (omitting the case with less than 256 99 * bytes to fill for simplicity). 100 * 101 * 1. Fill the buffer with 256 + STARTDATA_LEN bytes. 102 * 103 * 2. Search for the STARTDATA and SFNTS strings at positions 104 * buffer[0], buffer[1], ..., 105 * buffer[255 + STARTDATA_LEN - SFNTS_LEN]. 106 * 107 * 3. Move the last STARTDATA_LEN bytes to buffer[0]. 108 * 109 * 4. Fill the buffer with 256 bytes, starting at STARTDATA_LEN. 110 * 111 * 5. Repeat with step 2. 112 * 113 */ 114 FT_Byte buffer[256 + STARTDATA_LEN + 1]; 115 116 /* values for the first loop */ 117 FT_ULong read_len = 256 + STARTDATA_LEN; 118 FT_ULong read_offset = 0; 119 FT_Byte* p = buffer; 120 121 122 for ( offset = FT_STREAM_POS(); ; offset += 256 ) 123 { 124 FT_ULong stream_len; 125 126 127 stream_len = stream->size - FT_STREAM_POS(); 128 129 read_len = FT_MIN( read_len, stream_len ); 130 if ( FT_STREAM_READ( p, read_len ) ) 131 goto Exit; 132 133 /* ensure that we do not compare with data beyond the buffer */ 134 p[read_len] = '\0'; 135 136 limit = p + read_len - SFNTS_LEN; 137 138 for ( p = buffer; p < limit; p++ ) 139 { 140 if ( p[0] == 'S' && 141 ft_strncmp( (char*)p, STARTDATA, STARTDATA_LEN ) == 0 ) 142 { 143 /* save offset of binary data after `StartData' */ 144 offset += (FT_ULong)( p - buffer ) + STARTDATA_LEN + 1; 145 goto Found; 146 } 147 else if ( p[1] == 's' && 148 ft_strncmp( (char*)p, SFNTS, SFNTS_LEN ) == 0 ) 149 { 150 offset += (FT_ULong)( p - buffer ) + SFNTS_LEN + 1; 151 goto Found; 152 } 153 } 154 155 if ( read_offset + read_len < STARTDATA_LEN ) 156 { 157 FT_TRACE2(( "cid_parser_new: no `StartData' keyword found\n" )); 158 error = FT_THROW( Invalid_File_Format ); 159 goto Exit; 160 } 161 162 FT_MEM_MOVE( buffer, 163 buffer + read_offset + read_len - STARTDATA_LEN, 164 STARTDATA_LEN ); 165 166 /* values for the next loop */ 167 read_len = 256; 168 read_offset = STARTDATA_LEN; 169 p = buffer + read_offset; 170 } 171 } 172 173 Found: 174 /* We have found the start of the binary data or the `/sfnts' token. */ 175 /* Now rewind and extract the frame corresponding to this PostScript */ 176 /* section. */ 177 178 ps_len = offset - base_offset; 179 if ( FT_STREAM_SEEK( base_offset ) || 180 FT_FRAME_EXTRACT( ps_len, parser->postscript ) ) 181 goto Exit; 182 183 parser->data_offset = offset; 184 parser->postscript_len = ps_len; 185 parser->root.base = parser->postscript; 186 parser->root.cursor = parser->postscript; 187 parser->root.limit = parser->root.cursor + ps_len; 188 parser->num_dict = FT_UINT_MAX; 189 190 /* Finally, we check whether `StartData' or `/sfnts' was real -- */ 191 /* it could be in a comment or string. We also get the arguments */ 192 /* of `StartData' to find out whether the data is represented in */ 193 /* binary or hex format. */ 194 195 arg1 = parser->root.cursor; 196 cid_parser_skip_PS_token( parser ); 197 cid_parser_skip_spaces ( parser ); 198 arg2 = parser->root.cursor; 199 cid_parser_skip_PS_token( parser ); 200 cid_parser_skip_spaces ( parser ); 201 202 limit = parser->root.limit; 203 cur = parser->root.cursor; 204 205 while ( cur <= limit - SFNTS_LEN ) 206 { 207 if ( parser->root.error ) 208 { 209 error = parser->root.error; 210 goto Exit; 211 } 212 213 if ( cur[0] == 'S' && 214 cur <= limit - STARTDATA_LEN && 215 ft_strncmp( (char*)cur, STARTDATA, STARTDATA_LEN ) == 0 ) 216 { 217 T1_TokenRec type_token; 218 FT_Long binary_length; 219 220 221 parser->root.cursor = arg1; 222 cid_parser_to_token( parser, &type_token ); 223 if ( type_token.limit - type_token.start == 5 && 224 ft_memcmp( (char*)type_token.start, "(Hex)", 5 ) == 0 ) 225 { 226 parser->root.cursor = arg2; 227 binary_length = cid_parser_to_int( parser ); 228 if ( binary_length < 0 ) 229 { 230 FT_ERROR(( "cid_parser_new: invalid length of hex data\n" )); 231 error = FT_THROW( Invalid_File_Format ); 232 } 233 else 234 parser->binary_length = (FT_ULong)binary_length; 235 } 236 237 goto Exit; 238 } 239 else if ( cur[1] == 's' && 240 ft_strncmp( (char*)cur, SFNTS, SFNTS_LEN ) == 0 ) 241 { 242 FT_TRACE2(( "cid_parser_new: cannot handle Type 11 fonts\n" )); 243 error = FT_THROW( Unknown_File_Format ); 244 goto Exit; 245 } 246 247 cid_parser_skip_PS_token( parser ); 248 cid_parser_skip_spaces ( parser ); 249 arg1 = arg2; 250 arg2 = cur; 251 cur = parser->root.cursor; 252 } 253 254 /* we haven't found the correct `StartData'; go back and continue */ 255 /* searching */ 256 FT_FRAME_RELEASE( parser->postscript ); 257 if ( !FT_STREAM_SEEK( offset ) ) 258 goto Again; 259 260 Exit: 261 return error; 262 } 263 264 265 #undef STARTDATA 266 #undef STARTDATA_LEN 267 #undef SFNTS 268 #undef SFNTS_LEN 269 270 271 FT_LOCAL_DEF( void ) cid_parser_done(CID_Parser * parser)272 cid_parser_done( CID_Parser* parser ) 273 { 274 /* always free the private dictionary */ 275 if ( parser->postscript ) 276 { 277 FT_Stream stream = parser->stream; 278 279 280 FT_FRAME_RELEASE( parser->postscript ); 281 } 282 parser->root.funcs.done( &parser->root ); 283 } 284 285 286 /* END */ 287