/***************************************************************************/ | |
/* */ | |
/* t1parse.c */ | |
/* */ | |
/* Type 1 parser (body). */ | |
/* */ | |
/* Copyright 1996-2015 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_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 *****/ | |
/***** *****/ | |
/*************************************************************************/ | |
/*************************************************************************/ | |
/*************************************************************************/ | |
/* see Adobe Technical Note 5040.Download_Fonts.pdf */ | |
static FT_Error | |
read_pfb_tag( FT_Stream stream, | |
FT_UShort *atag, | |
FT_ULong *asize ) | |
{ | |
FT_Error error; | |
FT_UShort tag; | |
FT_ULong size; | |
*atag = 0; | |
*asize = 0; | |
if ( !FT_READ_USHORT( tag ) ) | |
{ | |
if ( tag == 0x8001U || tag == 0x8002U ) | |
{ | |
if ( !FT_READ_ULONG_LE( size ) ) | |
*asize = size; | |
} | |
*atag = tag; | |
} | |
return error; | |
} | |
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; | |
if ( FT_STREAM_SEEK( 0 ) ) | |
goto Exit; | |
error = read_pfb_tag( stream, &tag, &dummy ); | |
if ( error ) | |
goto Exit; | |
/* 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; | |
if ( !FT_FRAME_ENTER( header_length ) ) | |
{ | |
error = FT_Err_Ok; | |
if ( ft_memcmp( stream->cursor, header_string, header_length ) != 0 ) | |
error = FT_THROW( Unknown_File_Format ); | |
FT_FRAME_EXIT(); | |
} | |
Exit: | |
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_ULong size; | |
psaux->ps_parser_funcs->init( &parser->root, NULL, NULL, memory ); | |
parser->stream = stream; | |
parser->base_len = 0; | |
parser->base_dict = NULL; | |
parser->private_len = 0; | |
parser->private_dict = NULL; | |
parser->in_pfb = 0; | |
parser->in_memory = 0; | |
parser->single_block = 0; | |
/* check the header format */ | |
error = check_type1_format( stream, "%!PS-AdobeFont", 14 ); | |
if ( error ) | |
{ | |
if ( FT_ERR_NEQ( error, Unknown_File_Format ) ) | |
goto Exit; | |
error = check_type1_format( stream, "%!FontType", 10 ); | |
if ( error ) | |
{ | |
FT_TRACE2(( " not a Type 1 font\n" )); | |
goto Exit; | |
} | |
} | |
/******************************************************************/ | |
/* */ | |
/* 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 -- 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; | |
} | |
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 ); | |
} | |
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; | |
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_ULong 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:" | |
" invalid private dictionary section\n" )); | |
error = FT_THROW( 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 = FT_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_Pointer pos_lf; | |
FT_Bool test_cr; | |
Again: | |
for (;;) | |
{ | |
if ( cur[0] == '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; | |
} | |
} | |
/* check whether `eexec' was real -- it could be in a comment */ | |
/* or string (as e.g. in u003043t.gsf from ghostscript) */ | |
parser->root.cursor = parser->base_dict; | |
/* set limit to `eexec' + whitespace + 4 characters */ | |
parser->root.limit = cur + 10; | |
cur = parser->root.cursor; | |
limit = parser->root.limit; | |
while ( cur < limit ) | |
{ | |
if ( cur[0] == 'e' && | |
cur + 5 < limit ) | |
{ | |
if ( cur[1] == 'e' && | |
cur[2] == 'x' && | |
cur[3] == 'e' && | |
cur[4] == 'c' ) | |
goto Found; | |
} | |
T1_Skip_PS_Token( parser ); | |
if ( parser->root.error ) | |
break; | |
T1_Skip_Spaces ( parser ); | |
cur = parser->root.cursor; | |
} | |
/* we haven't found the correct `eexec'; go back and continue */ | |
/* searching */ | |
cur = limit; | |
limit = parser->base_dict + parser->base_len; | |
if ( cur >= limit ) | |
{ | |
FT_ERROR(( "T1_Get_Private_Dict:" | |
" premature end in private dictionary\n" )); | |
error = FT_THROW( Invalid_File_Format ); | |
goto Exit; | |
} | |
goto Again; | |
/* 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 */ | |
Found: | |
parser->root.limit = parser->base_dict + parser->base_len; | |
T1_Skip_PS_Token( parser ); | |
cur = parser->root.cursor; | |
limit = parser->root.limit; | |
/* According to the Type 1 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. */ | |
/* */ | |
/* On the other hand, Adobe's Type 1 parser handles fonts just */ | |
/* fine that are violating this limitation, so we add a heuristic */ | |
/* test to stop at \r only if it is not used for EOL. */ | |
pos_lf = ft_memchr( cur, '\n', (size_t)( limit - cur ) ); | |
test_cr = FT_BOOL( !pos_lf || | |
pos_lf > ft_memchr( cur, | |
'\r', | |
(size_t)( limit - cur ) ) ); | |
while ( cur < limit && | |
( *cur == ' ' || | |
*cur == '\t' || | |
(test_cr && *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; | |
} | |
size = parser->base_len - (FT_ULong)( 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 = NULL; | |
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 whitespace */ | |
/* following the `eexec' keyword); if they all are hexadecimal */ | |
/* digits, then we have a case of ASCII storage */ | |
if ( cur + 3 < limit && | |
ft_isxdigit( cur[0] ) && ft_isxdigit( cur[1] ) && | |
ft_isxdigit( cur[2] ) && ft_isxdigit( cur[3] ) ) | |
{ | |
/* ASCII hexadecimal encoding */ | |
FT_ULong len; | |
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; | |
/* put a safeguard */ | |
parser->private_dict[len] = '\0'; | |
} | |
else | |
/* binary encoding -- copy the private dict */ | |
FT_MEM_MOVE( parser->private_dict, cur, size ); | |
} | |
/* we now decrypt the encoded binary private dictionary */ | |
psaux->t1_decrypt( parser->private_dict, parser->private_len, 55665U ); | |
if ( parser->private_len < 4 ) | |
{ | |
FT_ERROR(( "T1_Get_Private_Dict:" | |
" invalid private dictionary section\n" )); | |
error = FT_THROW( Invalid_File_Format ); | |
goto Fail; | |
} | |
/* 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] = ' '; | |
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 */ |