/***************************************************************************/
/* */
/* t1parse.c */
/* */
/* Type 1 parser (body). */
/* */
/* Copyright 1996-2000 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 <freetype/internal/ftdebug.h>
#include <freetype/internal/ftcalc.h>
#include <freetype/internal/ftobjs.h>
#include <freetype/internal/ftstream.h>
#include <freetype/internal/t1errors.h>
#include <freetype/internal/psaux.h>
#ifdef FT_FLAT_COMPILE
#include "t1parse.h"
#else
#include <type1/t1parse.h>
#endif
#include <string.h> /* for strncmp() */
/*************************************************************************/
/* */
/* 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 ( !READ_Fields( pfb_tag_fields, &head ) )
{
if ( head.tag == 0x8001 || head.tag == 0x8002 )
{
*tag = head.tag;
*size = head.size;
}
}
return error;
}
LOCAL_FUNC
FT_Error T1_New_Parser( T1_ParserRec* parser,
FT_Stream stream,
FT_Memory memory,
PSAux_Interface* psaux )
{
FT_Error error;
FT_UShort tag;
FT_Long size;
psaux->t1_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 ( FILE_Seek( 0L ) )
goto Exit;
error = read_pfb_tag( stream, &tag, &size );
if ( error )
goto Exit;
if ( tag != 0x8001 )
{
/* assume that this is a PFA file for now; an error will */
/* be produced later when more things are checked */
if ( FILE_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 ( FILE_Skip( size ) )
goto Exit;
}
else
{
/* read segment in memory */
if ( ALLOC( parser->base_dict, size ) ||
FILE_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 ||
( strncmp( (const char*)parser->base_dict,
"%!PS-AdobeFont-1", 16 ) &&
strncmp( (const char*)parser->base_dict,
"%!FontType", 10 ) ) )
{
FT_TRACE2(( "[not a Type1 font]\n" ));
error = FT_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 )
FREE( parser->base_dict );
return error;
}
LOCAL_FUNC
void T1_Done_Parser( T1_ParserRec* parser )
{
FT_Memory memory = parser->root.memory;
/* always free the private dictionary */
FREE( parser->private_dict );
/* free the base dictionary only when we have a disk stream */
if ( !parser->in_memory )
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;
}
LOCAL_FUNC
void T1_Decrypt( FT_Byte* buffer,
FT_Int length,
FT_UShort seed )
{
while ( length > 0 )
{
FT_Byte plain;
plain = ( *buffer ^ ( seed >> 8 ) );
seed = ( *buffer + seed ) * 52845 + 22719;
*buffer++ = plain;
length--;
}
}
LOCAL_FUNC
FT_Error T1_Get_Private_Dict( T1_ParserRec* parser )
{
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 = FILE_Pos();
FT_UShort tag;
parser->private_len = 0;
for (;;)
{
error = read_pfb_tag( stream, &tag, &size );
if ( error )
goto Fail;
if ( tag != 0x8002 )
break;
parser->private_len += size;
if ( FILE_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 ( FILE_Seek( start_pos ) ||
ALLOC( parser->private_dict, parser->private_len ) )
goto Fail;
parser->private_len = 0;
for (;;)
{
error = read_pfb_tag( stream, &tag, &size );
if ( error || tag != 0x8002 )
{
error = FT_Err_Ok;
break;
}
if ( FILE_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 = parser->base_len - ( cur - parser->base_dict);
if ( parser->in_memory )
{
/* note that we allocate one more byte to put a terminating `0' */
if ( 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 */
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++ = ( 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 */
T1_Decrypt( parser->private_dict, parser->private_len, 55665 );
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 */
