diff options
Diffstat (limited to 'src/type1/t1parse.c')
| -rw-r--r-- | src/type1/t1parse.c | 479 |
1 files changed, 479 insertions, 0 deletions
diff --git a/src/type1/t1parse.c b/src/type1/t1parse.c new file mode 100644 index 0000000..1b252c7 --- /dev/null +++ b/src/type1/t1parse.c @@ -0,0 +1,479 @@ +/***************************************************************************/ +/* */ +/* t1parse.c */ +/* */ +/* Type 1 parser (body). */ +/* */ +/* Copyright 1996-2001, 2002, 2003, 2004, 2005 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 *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + /*************************************************************************/ + + + static FT_Error + read_pfb_tag( FT_Stream stream, + FT_UShort *atag, + FT_Long *asize ) + { + FT_Error error; + FT_UShort tag; + FT_Long size; + + + *atag = 0; + *asize = 0; + + if ( !FT_READ_USHORT( tag ) ) + { + if ( tag == 0x8001U || tag == 0x8002U ) + { + if ( !FT_READ_LONG_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_Long size; + + + if ( FT_STREAM_SEEK( 0 ) ) + goto Exit; + + error = read_pfb_tag( stream, &tag, &size ); + if ( error ) + goto Exit; + + if ( tag != 0x8001U && FT_STREAM_SEEK( 0 ) ) + goto Exit; + + if ( !FT_FRAME_ENTER( header_length ) ) + { + error = 0; + + if ( ft_memcmp( stream->cursor, header_string, header_length ) != 0 ) + error = T1_Err_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_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; + + /* check the header format */ + error = check_type1_format( stream, "%!PS-AdobeFont", 14 ); + if ( error ) + { + if ( error != T1_Err_Unknown_File_Format ) + goto Exit; + + error = check_type1_format( stream, "%!FontType", 10 ); + if ( error ) + { + FT_TRACE2(( "[not a Type1 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 = T1_Err_Ok; + 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; + + + Again: + 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' ) + 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; + } + } + + /* 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; + parser->root.limit = cur + 9; + + 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; + if ( *cur == '\r' ) + { + cur++; + if ( *cur == '\n' ) + cur++; + } + else if ( *cur == '\n' ) + cur++; + else + { + FT_ERROR(( "T1_Get_Private_Dict:" )); + FT_ERROR(( " `eexec' not properly terminated\n" )); + error = T1_Err_Invalid_File_Format; + goto Exit; + } + + 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 ( ft_isxdigit( cur[0] ) && ft_isxdigit( cur[1] ) && + ft_isxdigit( cur[2] ) && ft_isxdigit( cur[3] ) ) + { + /* ASCII hexadecimal encoding */ + FT_Long 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 ); + + /* 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 */ |