Edit
kc3-lang/freetype/src/sfnt/sfwoff.c
Werner Lemberg
- src/sfnt/sfwoff.c
-
/**************************************************************************** * * sfwoff.c * * WOFF format management (base). * * Copyright (C) 1996-2020 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 "sfwoff.h" #include <freetype/tttags.h> #include <freetype/internal/ftdebug.h> #include <freetype/internal/ftstream.h> #include <freetype/ftgzip.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 sfwoff #define WRITE_USHORT( p, v ) \ do \ { \ *(p)++ = (FT_Byte)( (v) >> 8 ); \ *(p)++ = (FT_Byte)( (v) >> 0 ); \ \ } while ( 0 ) #define WRITE_ULONG( p, v ) \ do \ { \ *(p)++ = (FT_Byte)( (v) >> 24 ); \ *(p)++ = (FT_Byte)( (v) >> 16 ); \ *(p)++ = (FT_Byte)( (v) >> 8 ); \ *(p)++ = (FT_Byte)( (v) >> 0 ); \ \ } while ( 0 ) static void sfnt_stream_close( FT_Stream stream ) { FT_Memory memory = stream->memory; FT_FREE( stream->base ); stream->size = 0; stream->base = NULL; stream->close = NULL; } FT_CALLBACK_DEF( int ) compare_offsets( const void* a, const void* b ) { WOFF_Table table1 = *(WOFF_Table*)a; WOFF_Table table2 = *(WOFF_Table*)b; FT_ULong offset1 = table1->Offset; FT_ULong offset2 = table2->Offset; if ( offset1 > offset2 ) return 1; else if ( offset1 < offset2 ) return -1; else return 0; } /* Replace `face->root.stream' with a stream containing the extracted */ /* SFNT of a WOFF font. */ FT_LOCAL_DEF( FT_Error ) woff_open_font( FT_Stream stream, TT_Face face ) { FT_Memory memory = stream->memory; FT_Error error = FT_Err_Ok; WOFF_HeaderRec woff; WOFF_Table tables = NULL; WOFF_Table* indices = NULL; FT_ULong woff_offset; FT_Byte* sfnt = NULL; FT_Stream sfnt_stream = NULL; FT_Byte* sfnt_header; FT_ULong sfnt_offset; FT_Int nn; FT_ULong old_tag = 0; static const FT_Frame_Field woff_header_fields[] = { #undef FT_STRUCTURE #define FT_STRUCTURE WOFF_HeaderRec FT_FRAME_START( 44 ), FT_FRAME_ULONG ( signature ), FT_FRAME_ULONG ( flavor ), FT_FRAME_ULONG ( length ), FT_FRAME_USHORT( num_tables ), FT_FRAME_USHORT( reserved ), FT_FRAME_ULONG ( totalSfntSize ), FT_FRAME_USHORT( majorVersion ), FT_FRAME_USHORT( minorVersion ), FT_FRAME_ULONG ( metaOffset ), FT_FRAME_ULONG ( metaLength ), FT_FRAME_ULONG ( metaOrigLength ), FT_FRAME_ULONG ( privOffset ), FT_FRAME_ULONG ( privLength ), FT_FRAME_END }; FT_ASSERT( stream == face->root.stream ); FT_ASSERT( FT_STREAM_POS() == 0 ); if ( FT_STREAM_READ_FIELDS( woff_header_fields, &woff ) ) return error; /* Make sure we don't recurse back here or hit TTC code. */ if ( woff.flavor == TTAG_wOFF || woff.flavor == TTAG_ttcf ) return FT_THROW( Invalid_Table ); /* Miscellaneous checks. */ if ( woff.length != stream->size || woff.num_tables == 0 || 44 + woff.num_tables * 20UL >= woff.length || 12 + woff.num_tables * 16UL >= woff.totalSfntSize || ( woff.totalSfntSize & 3 ) != 0 || ( woff.metaOffset == 0 && ( woff.metaLength != 0 || woff.metaOrigLength != 0 ) ) || ( woff.metaLength != 0 && woff.metaOrigLength == 0 ) || ( woff.privOffset == 0 && woff.privLength != 0 ) ) { FT_ERROR(( "woff_font_open: invalid WOFF header\n" )); return FT_THROW( Invalid_Table ); } /* Don't trust `totalSfntSize' before thorough checks. */ if ( FT_ALLOC( sfnt, 12 + woff.num_tables * 16UL ) || FT_NEW( sfnt_stream ) ) goto Exit; sfnt_header = sfnt; /* Write sfnt header. */ { FT_UInt searchRange, entrySelector, rangeShift, x; x = woff.num_tables; entrySelector = 0; while ( x ) { x >>= 1; entrySelector += 1; } entrySelector--; searchRange = ( 1 << entrySelector ) * 16; rangeShift = woff.num_tables * 16 - searchRange; WRITE_ULONG ( sfnt_header, woff.flavor ); WRITE_USHORT( sfnt_header, woff.num_tables ); WRITE_USHORT( sfnt_header, searchRange ); WRITE_USHORT( sfnt_header, entrySelector ); WRITE_USHORT( sfnt_header, rangeShift ); } /* While the entries in the sfnt header must be sorted by the */ /* tag value, the tables themselves are not. We thus have to */ /* sort them by offset and check that they don't overlap. */ if ( FT_NEW_ARRAY( tables, woff.num_tables ) || FT_NEW_ARRAY( indices, woff.num_tables ) ) goto Exit; FT_TRACE2(( "\n" " tag offset compLen origLen checksum\n" " -------------------------------------------\n" )); if ( FT_FRAME_ENTER( 20L * woff.num_tables ) ) goto Exit; for ( nn = 0; nn < woff.num_tables; nn++ ) { WOFF_Table table = tables + nn; table->Tag = FT_GET_TAG4(); table->Offset = FT_GET_ULONG(); table->CompLength = FT_GET_ULONG(); table->OrigLength = FT_GET_ULONG(); table->CheckSum = FT_GET_ULONG(); FT_TRACE2(( " %c%c%c%c %08lx %08lx %08lx %08lx\n", (FT_Char)( table->Tag >> 24 ), (FT_Char)( table->Tag >> 16 ), (FT_Char)( table->Tag >> 8 ), (FT_Char)( table->Tag ), table->Offset, table->CompLength, table->OrigLength, table->CheckSum )); if ( table->Tag <= old_tag ) { FT_FRAME_EXIT(); FT_ERROR(( "woff_font_open: table tags are not sorted\n" )); error = FT_THROW( Invalid_Table ); goto Exit; } old_tag = table->Tag; indices[nn] = table; } FT_FRAME_EXIT(); /* Sort by offset. */ ft_qsort( indices, woff.num_tables, sizeof ( WOFF_Table ), compare_offsets ); /* Check offsets and lengths. */ woff_offset = 44 + woff.num_tables * 20L; sfnt_offset = 12 + woff.num_tables * 16L; for ( nn = 0; nn < woff.num_tables; nn++ ) { WOFF_Table table = indices[nn]; if ( table->Offset != woff_offset || table->CompLength > woff.length || table->Offset > woff.length - table->CompLength || table->OrigLength > woff.totalSfntSize || sfnt_offset > woff.totalSfntSize - table->OrigLength || table->CompLength > table->OrigLength ) { FT_ERROR(( "woff_font_open: invalid table offsets\n" )); error = FT_THROW( Invalid_Table ); goto Exit; } table->OrigOffset = sfnt_offset; /* The offsets must be multiples of 4. */ woff_offset += ( table->CompLength + 3 ) & ~3U; sfnt_offset += ( table->OrigLength + 3 ) & ~3U; } /* * Final checks! * * We don't decode and check the metadata block. * We don't check table checksums either. * But other than those, I think we implement all * `MUST' checks from the spec. */ if ( woff.metaOffset ) { if ( woff.metaOffset != woff_offset || woff.metaOffset + woff.metaLength > woff.length ) { FT_ERROR(( "woff_font_open:" " invalid `metadata' offset or length\n" )); error = FT_THROW( Invalid_Table ); goto Exit; } /* We have padding only ... */ woff_offset += woff.metaLength; } if ( woff.privOffset ) { /* ... if it isn't the last block. */ woff_offset = ( woff_offset + 3 ) & ~3U; if ( woff.privOffset != woff_offset || woff.privOffset + woff.privLength > woff.length ) { FT_ERROR(( "woff_font_open: invalid `private' offset or length\n" )); error = FT_THROW( Invalid_Table ); goto Exit; } /* No padding for the last block. */ woff_offset += woff.privLength; } if ( sfnt_offset != woff.totalSfntSize || woff_offset != woff.length ) { FT_ERROR(( "woff_font_open: invalid `sfnt' table structure\n" )); error = FT_THROW( Invalid_Table ); goto Exit; } /* Now use `totalSfntSize'. */ if ( FT_REALLOC( sfnt, 12 + woff.num_tables * 16UL, woff.totalSfntSize ) ) goto Exit; sfnt_header = sfnt + 12; /* Write the tables. */ for ( nn = 0; nn < woff.num_tables; nn++ ) { WOFF_Table table = tables + nn; /* Write SFNT table entry. */ WRITE_ULONG( sfnt_header, table->Tag ); WRITE_ULONG( sfnt_header, table->CheckSum ); WRITE_ULONG( sfnt_header, table->OrigOffset ); WRITE_ULONG( sfnt_header, table->OrigLength ); /* Write table data. */ if ( FT_STREAM_SEEK( table->Offset ) || FT_FRAME_ENTER( table->CompLength ) ) goto Exit; if ( table->CompLength == table->OrigLength ) { /* Uncompressed data; just copy. */ ft_memcpy( sfnt + table->OrigOffset, stream->cursor, table->OrigLength ); } else { #ifdef FT_CONFIG_OPTION_USE_ZLIB /* Uncompress with zlib. */ FT_ULong output_len = table->OrigLength; error = FT_Gzip_Uncompress( memory, sfnt + table->OrigOffset, &output_len, stream->cursor, table->CompLength ); if ( error ) goto Exit1; if ( output_len != table->OrigLength ) { FT_ERROR(( "woff_font_open: compressed table length mismatch\n" )); error = FT_THROW( Invalid_Table ); goto Exit1; } #else /* !FT_CONFIG_OPTION_USE_ZLIB */ error = FT_THROW( Unimplemented_Feature ); goto Exit1; #endif /* !FT_CONFIG_OPTION_USE_ZLIB */ } FT_FRAME_EXIT(); /* We don't check whether the padding bytes in the WOFF file are */ /* actually '\0'. For the output, however, we do set them properly. */ sfnt_offset = table->OrigOffset + table->OrigLength; while ( sfnt_offset & 3 ) { sfnt[sfnt_offset] = '\0'; sfnt_offset++; } } /* Ok! Finally ready. Swap out stream and return. */ FT_Stream_OpenMemory( sfnt_stream, sfnt, woff.totalSfntSize ); sfnt_stream->memory = stream->memory; sfnt_stream->close = sfnt_stream_close; FT_Stream_Free( face->root.stream, ( face->root.face_flags & FT_FACE_FLAG_EXTERNAL_STREAM ) != 0 ); face->root.stream = sfnt_stream; face->root.face_flags &= ~FT_FACE_FLAG_EXTERNAL_STREAM; Exit: FT_FREE( tables ); FT_FREE( indices ); if ( error ) { FT_FREE( sfnt ); FT_Stream_Close( sfnt_stream ); FT_FREE( sfnt_stream ); } return error; Exit1: FT_FRAME_EXIT(); goto Exit; } #undef WRITE_USHORT #undef WRITE_ULONG /* END */