Module: Sdkey::Crypto::CanonicalJson

Defined in:
lib/sdkey/crypto/canonical_json.rb

Overview

Deterministic JSON encoding for Ed25519 signing. Object keys sorted lexicographically, no insignificant whitespace.

Class Method Summary collapse

Class Method Details

.canonical_json(value) ⇒ Object 



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# File 'lib/sdkey/crypto/canonical_json.rb', line 12

def canonical_json(value)
  canonicalize(value).encode("UTF-8")
end

.canonicalize(value) ⇒ Object 



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# File 'lib/sdkey/crypto/canonical_json.rb', line 16

def canonicalize(value)
  case value
  when nil
    "null"
  when true
    "true"
  when false
    "false"
  when Integer
    value.to_s
  when Float
    raise ArgumentError, "canonicalJson: non-finite numbers are not allowed" unless value.finite?

    JSON.generate(value)
  when String
    JSON.generate(value)
  when Array
    "[#{value.map { |item| canonicalize(item) }.join(",")}]"
  when Hash
    stringified = {}
    value.each { |k, v| stringified[k.to_s] = v }
    keys = stringified.keys.sort
    body = keys.map do |key|
      "#{JSON.generate(key)}:#{canonicalize(stringified[key])}"
    end.join(",")
    "{#{body}}"
  else
    raise TypeError, "canonicalJson: unsupported type #{value.class}"
  end
end