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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /modules/freetype2/src/type1/t1parse.c | |
parent | Initial commit. (diff) | |
download | thunderbird-upstream.tar.xz thunderbird-upstream.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'modules/freetype2/src/type1/t1parse.c')
-rw-r--r-- | modules/freetype2/src/type1/t1parse.c | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/modules/freetype2/src/type1/t1parse.c b/modules/freetype2/src/type1/t1parse.c new file mode 100644 index 0000000000..6dec6c16c3 --- /dev/null +++ b/modules/freetype2/src/type1/t1parse.c @@ -0,0 +1,487 @@ +/**************************************************************************** + * + * t1parse.c + * + * Type 1 parser (body). + * + * Copyright (C) 1996-2023 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/ftstream.h> +#include <freetype/internal/psaux.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 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_QALLOC( 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_QALLOC( 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 look for the `eexec' keyword. Ensure `eexec' is real -- */ + /* it could be in a comment or string (as e.g. in u003043t.gsf */ + /* from ghostscript). */ + FT_Byte* cur = parser->base_dict; + FT_Byte* limit = cur + parser->base_len; + FT_Pointer pos_lf; + FT_Bool test_cr; + + + parser->root.cursor = parser->base_dict; + parser->root.limit = parser->base_dict + parser->base_len; + + cur = parser->root.cursor; + limit = parser->root.limit; + + while ( cur < limit ) + { + /* 9 = 5 letters for `eexec' + whitespace + 4 chars */ + if ( cur[0] == 'e' && cur + 9 < 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; + } + + FT_ERROR(( "T1_Get_Private_Dict: could not find `eexec' keyword\n" )); + error = FT_THROW( 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 */ + + 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_QALLOC( 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 */ |