C++ PSAux_Service::t1_decrypt方法代码示例

//.........这里部分代码省略.........
    }

    else

#endif /* FT_CONFIG_OPTION_INCREMENTAL */

    /* For ordinary fonts read the CID font dictionary index */
    /* and charstring offset from the CIDMap.                */
    {
      FT_UInt   entry_len = cid->fd_bytes + cid->gd_bytes;
      FT_ULong  off1;


      if ( FT_STREAM_SEEK( cid->data_offset + cid->cidmap_offset +
                           glyph_index * entry_len )               ||
           FT_FRAME_ENTER( 2 * entry_len )                         )
        goto Exit;

      p            = (FT_Byte*)stream->cursor;
      fd_select    = (FT_UInt) cid_get_offset( &p, (FT_Byte)cid->fd_bytes );
      off1         = (FT_ULong)cid_get_offset( &p, (FT_Byte)cid->gd_bytes );
      p           += cid->fd_bytes;
      glyph_length = cid_get_offset( &p, (FT_Byte)cid->gd_bytes ) - off1;
      FT_FRAME_EXIT();

      if ( fd_select >= (FT_UInt)cid->num_dicts )
      {
        error = CID_Err_Invalid_Offset;
        goto Exit;
      }
      if ( glyph_length == 0 )
        goto Exit;
      if ( FT_ALLOC( charstring, glyph_length ) )
        goto Exit;
      if ( FT_STREAM_READ_AT( cid->data_offset + off1,
                              charstring, glyph_length ) )
        goto Exit;
    }

    /* Now set up the subrs array and parse the charstrings. */
    {
      CID_FaceDict  dict;
      CID_Subrs     cid_subrs = face->subrs + fd_select;
      FT_Int        cs_offset;


      /* Set up subrs */
      decoder->num_subrs = cid_subrs->num_subrs;
      decoder->subrs     = cid_subrs->code;
      decoder->subrs_len = 0;

      /* Set up font matrix */
      dict                 = cid->font_dicts + fd_select;

      decoder->font_matrix = dict->font_matrix;
      decoder->font_offset = dict->font_offset;
      decoder->lenIV       = dict->private_dict.lenIV;

      /* Decode the charstring. */

      /* Adjustment for seed bytes. */
      cs_offset = ( decoder->lenIV >= 0 ? decoder->lenIV : 0 );

      /* Decrypt only if lenIV >= 0. */
      if ( decoder->lenIV >= 0 )
        psaux->t1_decrypt( charstring, glyph_length, 4330 );

      error = decoder->funcs.parse_charstrings(
                decoder, charstring + cs_offset,
                (FT_Int)glyph_length - cs_offset );
    }

    FT_FREE( charstring );

#ifdef FT_CONFIG_OPTION_INCREMENTAL

    /* Incremental fonts can optionally override the metrics. */
    if ( !error && inc && inc->funcs->get_glyph_metrics )
    {
      FT_Incremental_MetricsRec  metrics;


      metrics.bearing_x = FIXED_TO_INT( decoder->builder.left_bearing.x );
      metrics.bearing_y = 0;
      metrics.advance   = FIXED_TO_INT( decoder->builder.advance.x );
      metrics.advance_v = FIXED_TO_INT( decoder->builder.advance.y );

      error = inc->funcs->get_glyph_metrics( inc->object,
                                             glyph_index, FALSE, &metrics );

      decoder->builder.left_bearing.x = INT_TO_FIXED( metrics.bearing_x );
      decoder->builder.advance.x      = INT_TO_FIXED( metrics.advance );
      decoder->builder.advance.y      = INT_TO_FIXED( metrics.advance_v );
    }

#endif /* FT_CONFIG_OPTION_INCREMENTAL */

  Exit:
    return error;
  }

//.........这里部分代码省略.........
      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 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.      */
      /* SumatraPDF: stop at \r if it's not used for EOL - cf. https://code.google.com/p/sumatrapdf/issues/detail?id=2408 */
      c = !memchr(cur, '\n', limit - cur) || memchr(cur, '\n', limit - cur) > memchr(cur, '\r', limit - cur);
      while ( cur < limit       &&
              ( *cur == ' '  ||
                *cur == '\t' ||
                ( c && *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 = (FT_ULong)( 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 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_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 );

    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;
  }

//.........这里部分代码省略.........
            /* XXX: Some fonts use DOS-linefeeds, i.e. \r\n; we need to */
            /*      skip the extra \n if we find it                     */
            if ( cur[0] == '\n' )
              cur++;

            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;
        }
      }

      /* 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                 */

      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 ( ( hexa_value( cur[0] ) | hexa_value( cur[1] ) |
             hexa_value( cur[2] ) | hexa_value( cur[3] ) ) < 0 )

        /* binary encoding -- `simply' copy the private dict */
        FT_MEM_COPY( parser->private_dict, cur, size );

      else
      {
        /* ASCII hexadecimal encoding */

        FT_Byte*  write;
        FT_Int    count;


        write = parser->private_dict;
        count = 0;

        for ( ;cur < limit; cur++ )
        {
          int  hex1;


          /* check for newline */
          if ( cur[0] == '\r' || cur[0] == '\n' )
            continue;

          /* exit if we have a non-hexadecimal digit that isn't a newline */
          hex1 = hexa_value( cur[0] );
          if ( hex1 < 0 || cur + 1 >= limit )
            break;

          /* otherwise, store byte */
          *write++ = (FT_Byte)( ( hex1 << 4 ) | hexa_value( cur[1] ) );
          count++;
          cur++;
        }

        /* put a safeguard */
        parser->private_len = write - parser->private_dict;
        *write++ = 0;
      }
    }

    /* we now decrypt the encoded binary private dictionary */
    psaux->t1_decrypt( parser->private_dict, parser->private_len, 55665U );
    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;
  }