| /***************************************************************************/ |
| /* */ |
| /* 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_Byte c; |
| FT_Pointer pos_lf; |
| FT_Bool test_cr; |
| |
| |
| 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; |
| } |
| } |
| |
| /* 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 == 'e' && ft_strncmp( (char*)cur, "eexec", 5 ) == 0 ) |
| 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; |
| 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 */ |
