ref: 1018d7a7091fd5e0433f501a3474cdc3fec322cc
dir: /libfreetype/t1parse.c/
/***************************************************************************/ /* */ /* t1parse.c */ /* */ /* Type 1 parser (body). */ /* */ /* Copyright 1996-2001, 2002 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. */ /* */ /***************************************************************************/ /*************************************************************************/ /* */ /* The Type 1 parser is in charge of the following: */ /* */ /* - provide an implementation of a growing sequence of objects called */ /* a `T1_Table' (used to build various tables needed by the loader). */ /* */ /* - opening .pfb and .pfa files to extract their top-level and private */ /* dictionaries. */ /* */ /* - read numbers, arrays & strings from any dictionary. */ /* */ /* See `t1load.c' to see how data is loaded from the font file. */ /* */ /*************************************************************************/ #include <ft2build.h> #include FT_INTERNAL_DEBUG_H #include FT_INTERNAL_CALC_H #include FT_INTERNAL_STREAM_H #include FT_INTERNAL_POSTSCRIPT_AUX_H #include "t1parse.h" #include "t1errors.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 trace_t1parse /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** INPUT STREAM PARSER *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ #define IS_T1_WHITESPACE( c ) ( (c) == ' ' || (c) == '\t' ) #define IS_T1_LINESPACE( c ) ( (c) == '\r' || (c) == '\n' ) #define IS_T1_SPACE( c ) ( IS_T1_WHITESPACE( c ) || IS_T1_LINESPACE( c ) ) typedef struct PFB_Tag_ { FT_UShort tag; FT_Long size; } PFB_Tag; #undef FT_STRUCTURE #define FT_STRUCTURE PFB_Tag static const FT_Frame_Field pfb_tag_fields[] = { FT_FRAME_START( 6 ), FT_FRAME_USHORT ( tag ), FT_FRAME_LONG_LE( size ), FT_FRAME_END }; static FT_Error read_pfb_tag( FT_Stream stream, FT_UShort* tag, FT_Long* size ) { FT_Error error; PFB_Tag head; *tag = 0; *size = 0; if ( !FT_STREAM_READ_FIELDS( pfb_tag_fields, &head ) ) { if ( head.tag == 0x8001U || head.tag == 0x8002U ) { *tag = head.tag; *size = head.size; } } return error; } FT_LOCAL_DEF( FT_Error ) T1_New_Parser( T1_Parser parser, FT_Stream stream, FT_Memory memory, PSAux_Service psaux ) { FT_Error error; FT_UShort tag; FT_Long size; psaux->ps_parser_funcs->init( &parser->root,0, 0, memory ); parser->stream = stream; parser->base_len = 0; parser->base_dict = 0; parser->private_len = 0; parser->private_dict = 0; parser->in_pfb = 0; parser->in_memory = 0; parser->single_block = 0; /******************************************************************/ /* */ /* Here a short summary of what is going on: */ /* */ /* When creating a new Type 1 parser, we try to locate and load */ /* the base dictionary if this is possible (i.e. for PFB */ /* files). Otherwise, we load the whole font into memory. */ /* */ /* When `loading' the base dictionary, we only setup pointers */ /* in the case of a memory-based stream. Otherwise, we */ /* allocate and load the base dictionary in it. */ /* */ /* parser->in_pfb is set if we are in a binary (".pfb") font. */ /* parser->in_memory is set if we have a memory stream. */ /* */ /* try to compute the size of the base dictionary; */ /* look for a Postscript binary file tag, i.e 0x8001 */ if ( FT_STREAM_SEEK( 0L ) ) goto Exit; error = read_pfb_tag( stream, &tag, &size ); if ( error ) goto Exit; if ( tag != 0x8001U ) { /* assume that this is a PFA file for now; an error will */ /* be produced later when more things are checked */ if ( FT_STREAM_SEEK( 0L ) ) goto Exit; size = stream->size; } else parser->in_pfb = 1; /* now, try to load `size' bytes of the `base' dictionary we */ /* found previously */ /* if it is a memory-based resource, set up pointers */ if ( !stream->read ) { parser->base_dict = (FT_Byte*)stream->base + stream->pos; parser->base_len = size; parser->in_memory = 1; /* check that the `size' field is valid */ if ( FT_STREAM_SKIP( size ) ) goto Exit; } else { /* read segment in memory */ if ( FT_ALLOC( parser->base_dict, size ) || FT_STREAM_READ( parser->base_dict, size ) ) goto Exit; parser->base_len = size; } /* Now check font format; we must see `%!PS-AdobeFont-1' */ /* or `%!FontType' */ { if ( size <= 16 || ( ft_strncmp( (const char*)parser->base_dict, "%!PS-AdobeFont-1", 16 ) && ft_strncmp( (const char*)parser->base_dict, "%!FontType", 10 ) ) ) { FT_TRACE2(( "[not a Type1 font]\n" )); error = T1_Err_Unknown_File_Format; } else { parser->root.base = parser->base_dict; parser->root.cursor = parser->base_dict; parser->root.limit = parser->root.cursor + parser->base_len; } } Exit: if ( error && !parser->in_memory ) FT_FREE( parser->base_dict ); return error; } FT_LOCAL_DEF( void ) T1_Finalize_Parser( T1_Parser parser ) { FT_Memory memory = parser->root.memory; /* always free the private dictionary */ FT_FREE( parser->private_dict ); /* free the base dictionary only when we have a disk stream */ if ( !parser->in_memory ) FT_FREE( parser->base_dict ); parser->root.funcs.done( &parser->root ); } /* return the value of an hexadecimal digit */ static int hexa_value( char c ) { unsigned int d; d = (unsigned int)( c - '0' ); if ( d <= 9 ) return (int)d; d = (unsigned int)( c - 'a' ); if ( d <= 5 ) return (int)( d + 10 ); d = (unsigned int)( c - 'A' ); if ( d <= 5 ) return (int)( d + 10 ); return -1; } FT_LOCAL_DEF( FT_Error ) T1_Get_Private_Dict( T1_Parser parser, PSAux_Service psaux ) { FT_Stream stream = parser->stream; FT_Memory memory = parser->root.memory; FT_Error error = 0; FT_Long size; if ( parser->in_pfb ) { /* in the case of the PFB format, the private dictionary can be */ /* made of several segments. We thus first read the number of */ /* segments to compute the total size of the private dictionary */ /* then re-read them into memory. */ FT_Long start_pos = FT_STREAM_POS(); FT_UShort tag; parser->private_len = 0; for (;;) { error = read_pfb_tag( stream, &tag, &size ); if ( error ) goto Fail; if ( tag != 0x8002U ) break; parser->private_len += size; if ( FT_STREAM_SKIP( size ) ) goto Fail; } /* Check that we have a private dictionary there */ /* and allocate private dictionary buffer */ if ( parser->private_len == 0 ) { FT_ERROR(( "T1_Get_Private_Dict:" )); FT_ERROR(( " invalid private dictionary section\n" )); error = T1_Err_Invalid_File_Format; goto Fail; } if ( FT_STREAM_SEEK( start_pos ) || FT_ALLOC( parser->private_dict, parser->private_len ) ) goto Fail; parser->private_len = 0; for (;;) { error = read_pfb_tag( stream, &tag, &size ); if ( error || tag != 0x8002U ) { error = T1_Err_Ok; break; } if ( FT_STREAM_READ( parser->private_dict + parser->private_len, size ) ) goto Fail; parser->private_len += size; } } else { /* we have already `loaded' the whole PFA font file into memory; */ /* if this is a memory resource, allocate a new block to hold */ /* the private dict. Otherwise, simply overwrite into the base */ /* dictionary block in the heap. */ /* first of all, look at the `eexec' keyword */ FT_Byte* cur = parser->base_dict; FT_Byte* limit = cur + parser->base_len; FT_Byte c; for (;;) { c = cur[0]; if ( c == 'e' && cur + 9 < limit ) /* 9 = 5 letters for `eexec' + */ /* newline + 4 chars */ { if ( cur[1] == 'e' && cur[2] == 'x' && cur[3] == 'e' && cur[4] == 'c' ) { cur += 6; /* we skip the newling after the `eexec' */ /* XXX: Some fonts use DOS-linefeeds, i.e. \r\n; we need to */ /* skip the extra \n if we find it */ if ( cur[0] == '\n' ) cur++; break; } } cur++; if ( cur >= limit ) { FT_ERROR(( "T1_Get_Private_Dict:" )); FT_ERROR(( " could not find `eexec' keyword\n" )); error = T1_Err_Invalid_File_Format; goto Exit; } } /* now determine where to write the _encrypted_ binary private */ /* dictionary. We overwrite the base dictionary for disk-based */ /* resources and allocate a new block otherwise */ size = (FT_Long)( parser->base_len - ( cur - parser->base_dict ) ); if ( parser->in_memory ) { /* note that we allocate one more byte to put a terminating `0' */ if ( FT_ALLOC( parser->private_dict, size + 1 ) ) goto Fail; parser->private_len = size; } else { parser->single_block = 1; parser->private_dict = parser->base_dict; parser->private_len = size; parser->base_dict = 0; parser->base_len = 0; } /* now determine whether the private dictionary is encoded in binary */ /* or hexadecimal ASCII format -- decode it accordingly */ /* we need to access the next 4 bytes (after the final \r following */ /* the `eexec' keyword); if they all are hexadecimal digits, then */ /* we have a case of ASCII storage */ if ( ( hexa_value( cur[0] ) | hexa_value( cur[1] ) | hexa_value( cur[2] ) | hexa_value( cur[3] ) ) < 0 ) /* binary encoding -- `simply' copy the private dict */ FT_MEM_COPY( parser->private_dict, cur, size ); else { /* ASCII hexadecimal encoding */ FT_Byte* write; FT_Int count; write = parser->private_dict; count = 0; for ( ;cur < limit; cur++ ) { int hex1; /* check for newline */ if ( cur[0] == '\r' || cur[0] == '\n' ) continue; /* exit if we have a non-hexadecimal digit that isn't a newline */ hex1 = hexa_value( cur[0] ); if ( hex1 < 0 || cur + 1 >= limit ) break; /* otherwise, store byte */ *write++ = (FT_Byte)( ( hex1 << 4 ) | hexa_value( cur[1] ) ); count++; cur++; } /* put a safeguard */ parser->private_len = write - parser->private_dict; *write++ = 0; } } /* we now decrypt the encoded binary private dictionary */ psaux->t1_decrypt( parser->private_dict, parser->private_len, 55665U ); parser->root.base = parser->private_dict; parser->root.cursor = parser->private_dict; parser->root.limit = parser->root.cursor + parser->private_len; Fail: Exit: return error; } /* END */