0,0 → 1,497 |
/***************************************************************************/ |
/* */ |
/* t1parse.c */ |
/* */ |
/* Type 1 parser (body). */ |
/* */ |
/* Copyright 1996-2005, 2008, 2009, 2012, 2013 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. */ |
/* */ |
/***************************************************************************/ |
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/*************************************************************************/ |
/* */ |
/* 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. */ |
/* */ |
/*************************************************************************/ |
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#include <ft2build.h> |
#include FT_INTERNAL_DEBUG_H |
#include FT_INTERNAL_STREAM_H |
#include FT_INTERNAL_POSTSCRIPT_AUX_H |
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#include "t1parse.h" |
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#include "t1errors.h" |
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/*************************************************************************/ |
/* */ |
/* 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 |
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/*************************************************************************/ |
/*************************************************************************/ |
/*************************************************************************/ |
/***** *****/ |
/***** INPUT STREAM PARSER *****/ |
/***** *****/ |
/*************************************************************************/ |
/*************************************************************************/ |
/*************************************************************************/ |
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/* see Adobe Technical Note 5040.Download_Fonts.pdf */ |
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static FT_Error |
read_pfb_tag( FT_Stream stream, |
FT_UShort *atag, |
FT_ULong *asize ) |
{ |
FT_Error error; |
FT_UShort tag; |
FT_ULong size; |
|
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*atag = 0; |
*asize = 0; |
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if ( !FT_READ_USHORT( tag ) ) |
{ |
if ( tag == 0x8001U || tag == 0x8002U ) |
{ |
if ( !FT_READ_ULONG_LE( size ) ) |
*asize = size; |
} |
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*atag = tag; |
} |
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return error; |
} |
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static FT_Error |
check_type1_format( FT_Stream stream, |
const char* header_string, |
size_t header_length ) |
{ |
FT_Error error; |
FT_UShort tag; |
FT_ULong dummy; |
|
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if ( FT_STREAM_SEEK( 0 ) ) |
goto Exit; |
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error = read_pfb_tag( stream, &tag, &dummy ); |
if ( error ) |
goto Exit; |
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/* We assume that the first segment in a PFB is always encoded as */ |
/* text. This might be wrong (and the specification doesn't insist */ |
/* on that), but we have never seen a counterexample. */ |
if ( tag != 0x8001U && FT_STREAM_SEEK( 0 ) ) |
goto Exit; |
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if ( !FT_FRAME_ENTER( header_length ) ) |
{ |
error = FT_Err_Ok; |
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if ( ft_memcmp( stream->cursor, header_string, header_length ) != 0 ) |
error = FT_THROW( Unknown_File_Format ); |
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FT_FRAME_EXIT(); |
} |
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Exit: |
return error; |
} |
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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_ULong size; |
|
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psaux->ps_parser_funcs->init( &parser->root, 0, 0, memory ); |
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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; |
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/* check the header format */ |
error = check_type1_format( stream, "%!PS-AdobeFont", 14 ); |
if ( error ) |
{ |
if ( FT_ERR_NEQ( error, Unknown_File_Format ) ) |
goto Exit; |
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error = check_type1_format( stream, "%!FontType", 10 ); |
if ( error ) |
{ |
FT_TRACE2(( " not a Type 1 font\n" )); |
goto Exit; |
} |
} |
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/******************************************************************/ |
/* */ |
/* 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; |
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error = read_pfb_tag( stream, &tag, &size ); |
if ( error ) |
goto Exit; |
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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 -- this is clumsy, but so does the format */ |
if ( FT_ALLOC( parser->base_dict, size ) || |
FT_STREAM_READ( parser->base_dict, size ) ) |
goto Exit; |
parser->base_len = size; |
} |
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parser->root.base = parser->base_dict; |
parser->root.cursor = parser->base_dict; |
parser->root.limit = parser->root.cursor + parser->base_len; |
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Exit: |
if ( error && !parser->in_memory ) |
FT_FREE( parser->base_dict ); |
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return error; |
} |
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FT_LOCAL_DEF( void ) |
T1_Finalize_Parser( T1_Parser parser ) |
{ |
FT_Memory memory = parser->root.memory; |
|
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/* always free the private dictionary */ |
FT_FREE( parser->private_dict ); |
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/* free the base dictionary only when we have a disk stream */ |
if ( !parser->in_memory ) |
FT_FREE( parser->base_dict ); |
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parser->root.funcs.done( &parser->root ); |
} |
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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 = FT_Err_Ok; |
FT_ULong size; |
|
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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; |
|
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parser->private_len = 0; |
for (;;) |
{ |
error = read_pfb_tag( stream, &tag, &size ); |
if ( error ) |
goto Fail; |
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if ( tag != 0x8002U ) |
break; |
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parser->private_len += size; |
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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:" |
" invalid private dictionary section\n" )); |
error = FT_THROW( Invalid_File_Format ); |
goto Fail; |
} |
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if ( FT_STREAM_SEEK( start_pos ) || |
FT_ALLOC( parser->private_dict, parser->private_len ) ) |
goto Fail; |
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parser->private_len = 0; |
for (;;) |
{ |
error = read_pfb_tag( stream, &tag, &size ); |
if ( error || tag != 0x8002U ) |
{ |
error = FT_Err_Ok; |
break; |
} |
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if ( FT_STREAM_READ( parser->private_dict + parser->private_len, |
size ) ) |
goto Fail; |
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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; |
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Again: |
for (;;) |
{ |
c = cur[0]; |
if ( c == 'e' && cur + 9 < limit ) /* 9 = 5 letters for `eexec' + */ |
/* whitespace + 4 chars */ |
{ |
if ( cur[1] == 'e' && |
cur[2] == 'x' && |
cur[3] == 'e' && |
cur[4] == 'c' ) |
break; |
} |
cur++; |
if ( cur >= limit ) |
{ |
FT_ERROR(( "T1_Get_Private_Dict:" |
" could not find `eexec' keyword\n" )); |
error = FT_THROW( Invalid_File_Format ); |
goto Exit; |
} |
} |
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/* check whether `eexec' was real -- it could be in a comment */ |
/* or string (as e.g. in u003043t.gsf from ghostscript) */ |
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parser->root.cursor = parser->base_dict; |
/* set limit to `eexec' + whitespace + 4 characters */ |
parser->root.limit = cur + 10; |
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cur = parser->root.cursor; |
limit = parser->root.limit; |
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while ( cur < limit ) |
{ |
if ( *cur == 'e' && ft_strncmp( (char*)cur, "eexec", 5 ) == 0 ) |
goto Found; |
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T1_Skip_PS_Token( parser ); |
if ( parser->root.error ) |
break; |
T1_Skip_Spaces ( parser ); |
cur = parser->root.cursor; |
} |
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/* we haven't found the correct `eexec'; go back and continue */ |
/* searching */ |
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cur = limit; |
limit = parser->base_dict + parser->base_len; |
goto Again; |
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/* 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 */ |
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Found: |
parser->root.limit = parser->base_dict + parser->base_len; |
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T1_Skip_PS_Token( parser ); |
cur = parser->root.cursor; |
limit = parser->root.limit; |
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/* according to the Type1 spec, the first cipher byte must not be */ |
/* an ASCII whitespace character code (blank, tab, carriage return */ |
/* or line feed). We have seen Type 1 fonts with two line feed */ |
/* characters... So skip now all whitespace character codes. */ |
while ( cur < limit && |
( *cur == ' ' || |
*cur == '\t' || |
*cur == '\r' || |
*cur == '\n' ) ) |
++cur; |
if ( cur >= limit ) |
{ |
FT_ERROR(( "T1_Get_Private_Dict:" |
" `eexec' not properly terminated\n" )); |
error = FT_THROW( Invalid_File_Format ); |
goto Exit; |
} |
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size = (FT_ULong)( parser->base_len - ( cur - parser->base_dict ) ); |
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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; |
} |
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/* now determine whether the private dictionary is encoded in binary */ |
/* or hexadecimal ASCII format -- decode it accordingly */ |
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/* we need to access the next 4 bytes (after the final whitespace */ |
/* following the `eexec' keyword); if they all are hexadecimal */ |
/* digits, then we have a case of ASCII storage */ |
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if ( cur + 3 < limit && |
ft_isxdigit( cur[0] ) && ft_isxdigit( cur[1] ) && |
ft_isxdigit( cur[2] ) && ft_isxdigit( cur[3] ) ) |
{ |
/* ASCII hexadecimal encoding */ |
FT_Long len; |
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parser->root.cursor = cur; |
(void)psaux->ps_parser_funcs->to_bytes( &parser->root, |
parser->private_dict, |
parser->private_len, |
&len, |
0 ); |
parser->private_len = len; |
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/* put a safeguard */ |
parser->private_dict[len] = '\0'; |
} |
else |
/* binary encoding -- copy the private dict */ |
FT_MEM_MOVE( parser->private_dict, cur, size ); |
} |
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/* we now decrypt the encoded binary private dictionary */ |
psaux->t1_decrypt( parser->private_dict, parser->private_len, 55665U ); |
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if ( parser->private_len < 4 ) |
{ |
FT_ERROR(( "T1_Get_Private_Dict:" |
" invalid private dictionary section\n" )); |
error = FT_THROW( Invalid_File_Format ); |
goto Fail; |
} |
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/* replace the four random bytes at the beginning with whitespace */ |
parser->private_dict[0] = ' '; |
parser->private_dict[1] = ' '; |
parser->private_dict[2] = ' '; |
parser->private_dict[3] = ' '; |
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parser->root.base = parser->private_dict; |
parser->root.cursor = parser->private_dict; |
parser->root.limit = parser->root.cursor + parser->private_len; |
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Fail: |
Exit: |
return error; |
} |
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/* END */ |