Class: Shugoi::Pow

Inherits:
Object
  • Object
show all
Defined in:
lib/shugoi/pow.rb

Overview

Proof-of-work anti-curl. Parité avec core.ts (module Node) :

salt = HMAC(secret, ts)
proof = "ts:nonce" où SHA256(salt:nonce) a >= POW_DIFFICULTY bits à zéro en tête.

Instance Method Summary collapse

Constructor Details

#initialize(signing_secret, difficulty = 10, ttl_ms = 120_000) ⇒ Pow

Returns a new instance of Pow.



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# File 'lib/shugoi/pow.rb', line 9

def initialize(signing_secret, difficulty = 10, ttl_ms = 120_000)
  @secret = signing_secret.to_s
  @difficulty = difficulty
  @ttl_ms = ttl_ms
end

Instance Method Details

#challenge ⇒ Object

Génère le challenge à injecter (window.__sg_pow).



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# File 'lib/shugoi/pow.rb', line 16

def challenge
  ts = Utils.now_sec
  { ts: ts, salt: salt(ts), difficulty: @difficulty }
end

#valid?(proof) ⇒ Boolean

Vérifie un proof "ts:nonce".

Returns:

  • (Boolean) 


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# File 'lib/shugoi/pow.rb', line 22

def valid?(proof)
  return false if proof.to_s.empty? || @secret.empty?
  ts_str, solution = proof.to_s.split(":", 2)
  return false if ts_str.nil? || solution.nil?

  ts = ts_str.to_i
  return false if ts.zero?
  return false if (Utils.now_ms - ts * 1000).abs > @ttl_ms

  digest = Utils.sha256_hex("#{salt(ts_str)}:#{solution}")
  Utils.leading_zero_bits(digest) >= @difficulty
end