Class: Tassadar::MPQ::BlockEncryptor
- Inherits:
-
Object
- Object
- Tassadar::MPQ::BlockEncryptor
- Defined in:
- lib/tassadar/mpq/block_encryptor.rb
Instance Attribute Summary collapse
-
#buffer ⇒ Object
Returns the value of attribute buffer.
-
#key ⇒ Object
Returns the value of attribute key.
-
#offset ⇒ Object
Returns the value of attribute offset.
-
#size ⇒ Object
Returns the value of attribute size.
Class Method Summary collapse
Instance Method Summary collapse
- #decrypt ⇒ Object
- #encrypt ⇒ Object
- #hash_string ⇒ Object
-
#initialize(key, offset, buffer, size) ⇒ BlockEncryptor
constructor
A new instance of BlockEncryptor.
Constructor Details
#initialize(key, offset, buffer, size) ⇒ BlockEncryptor
Returns a new instance of BlockEncryptor.
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# File 'lib/tassadar/mpq/block_encryptor.rb', line 6 def initialize(key, offset, buffer, size) @key = key @offset = offset @buffer = buffer @size = size end |
Instance Attribute Details
#buffer ⇒ Object
Returns the value of attribute buffer.
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# File 'lib/tassadar/mpq/block_encryptor.rb', line 4 def buffer @buffer end |
#key ⇒ Object
Returns the value of attribute key.
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# File 'lib/tassadar/mpq/block_encryptor.rb', line 4 def key @key end |
#offset ⇒ Object
Returns the value of attribute offset.
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# File 'lib/tassadar/mpq/block_encryptor.rb', line 4 def offset @offset end |
#size ⇒ Object
Returns the value of attribute size.
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# File 'lib/tassadar/mpq/block_encryptor.rb', line 4 def size @size end |
Class Method Details
.hash_string(key, offset) ⇒ Object
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# File 'lib/tassadar/mpq/block_encryptor.rb', line 13 def self.hash_string(key, offset) BlockEncryptor.new(key, offset, nil, nil).hash_string end |
Instance Method Details
#decrypt ⇒ Object
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# File 'lib/tassadar/mpq/block_encryptor.rb', line 17 def decrypt seed1 = hash_string seed2 = 0xEEEEEEEE result = "" size = @size while size >= 4 seed2 += encryption_table[0x400 + (seed1 & 0xFF)] seed2 &= 0xFFFFFFFF value = buffer.readbytes(4).unpack("V").first value = (value ^ (seed1 + seed2)) & 0xFFFFFFFF result += [value].pack("V") seed1 = ((~seed1 << 0x15) + 0x11111111) | (seed1 >> 0x0B) seed1 &= 0xFFFFFFFF seed2 = value + seed2 + (seed2 << 5) + 3 & 0xFFFFFFFF size = size - 4 end result end |
#encrypt ⇒ Object
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# File 'lib/tassadar/mpq/block_encryptor.rb', line 41 def encrypt seed1 = hash_string seed2 = 0xEEEEEEEE encrypted_block = [] while @size >= 4 seed2 += encryption_table[0x400 + (seed1 & 0xFF)] seed2 &= 0xFFFFFFFF value = buffer.readbytes(4).unpack("V").first value = (value ^ (seed1 + seed2)) & 0xFFFFFFFF encrypted_block << value seed = ((~seed1 << 0x15) + 0x11111111) | (seed1 >> 0x0B) seed2 = value + seed2 + (seed2 << 5) + 3 & 0xFFFFFFFF @size = @size - 4 end encrypted_block.pack("V*") end |
#hash_string ⇒ Object
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# File 'lib/tassadar/mpq/block_encryptor.rb', line 64 def hash_string seed1 = 0x7FED7FED seed2 = 0xEEEEEEEE @key.upcase.each_byte do |char| value = encryption_table[@offset + char] seed1 = (value ^ (seed1 + seed2)) & 0xFFFFFFFF seed2 = char + seed1 + seed2 + (seed2 << 5) + 3 & 0xFFFFFFFF end seed1 end |