75 lines
1.5 KiB
Ruby
75 lines
1.5 KiB
Ruby
# -*- coding: binary -*-
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##
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# Rex::OLE - an OLE implementation
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# written in 2010 by Joshua J. Drake <jduck [at] metasploit.com>
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##
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module Rex
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module OLE
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class MiniFAT < DIFAT
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#
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# low-level functions
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#
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def read
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@entries = []
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visited = []
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sect = @stg.header._sectMiniFatStart
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@stg.header._csectMiniFat.times { |idx|
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break if sect == SECT_END
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if (visited.include?(sect))
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raise RuntimeError, 'Sector chain loop detected (0x%08x)' % sect
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end
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visited << sect
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buf = @stg.read_sector(sect, @stg.header.sector_size)
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@stg.header.idx_per_sect.times { |idx|
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@entries << Util.get32(buf, (idx*4))
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}
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sect = @stg.next_sector(sect)
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}
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end
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def allocate_sector
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idx = @entries.index(SECT_FREE)
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if (not idx)
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# add a sector worth
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idx = @entries.length
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@stg.header.idx_per_sect.times {
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@entries << SECT_FREE
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}
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end
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# default mini-sectors to end of chain
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@entries[idx] = SECT_END
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idx
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end
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def write
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return if (@entries.length < 1)
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mf_start = nil
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mfs_count = 0
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prev_sect = nil
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copy = @entries.dup
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while (copy.length > 0)
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part = copy.slice!(0, @stg.header.idx_per_sect)
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sbuf = Util.pack32array(part)
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idx = @stg.write_sector(sbuf, nil, prev_sect)
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mfs_count += 1
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mf_start ||= idx
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end
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@stg.header._sectMiniFatStart = mf_start
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@stg.header._csectMiniFat = mfs_count
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end
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end
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end
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end
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