Module: RbNaCl::KeyComparator

Overview

Implements comparisons of keys

This permits both timing invariant equality tests, as well as lexicographical sorting.

Instance Method Summary collapse

Instance Method Details

#<=>(other) ⇒ 0, ...

spaceship operator

Parameters:

Returns:

  • (0)

    if the keys are equal

  • (1)

    if the key is larger than the other key

  • (-1)

    if the key is smaller than the other key

  • (nil)

    if comparison doesn't make sense


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# File 'lib/rbnacl/key_comparator.rb', line 19

def <=>(other)
  if KeyComparator > other.class
    other = other.to_bytes
  elsif other.respond_to?(:to_str)
    other = other.to_str
  else
    return nil
  end
  compare32(other)
end

#==(other) ⇒ true, false

equality operator

The equality operator is explicity defined, despite including Comparable and having a spaceship operator, so that if equality tests are desired, they can be timing invariant, without any chance that the further comparisons for greater than and less than can leak information. Maybe this is too paranoid, but I don't know how ruby works under the hood with comparable.

Parameters:

Returns:

  • (true)

    if the keys are equal

  • (false)

    if they keys are not equal


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# File 'lib/rbnacl/key_comparator.rb', line 43

def ==(other)
  if KeyComparator > other.class
    other = other.to_bytes
  elsif other.respond_to?(:to_str)
    other = other.to_str
  else
    return false
  end
  Util.verify32(to_bytes, other)
end