init

utils.js

@@ -0,0 +1,81 @@
+const fetch = require('node-fetch')
+const { isHexStrict } = require('web3-utils')
+const { gasOracleUrls } = require('./env.json')
+
+async function fetchGasPrice({ gasPrices, oracleIndex = 0 }) {
+  oracleIndex = (oracleIndex + 1) % gasOracleUrls.length
+  try {
+    const response = await fetch(gasOracleUrls[oracleIndex])
+    if (response.status === 200) {
+      const json = await response.json()
+
+      if (json.slow) {
+        gasPrices.low = Number(json.slow)
+      }
+      if (json.safeLow) {
+        gasPrices.low = Number(json.safeLow)
+      }
+      if (json.standard) {
+        gasPrices.standard = Number(json.standard)
+      }
+      if (json.fast) {
+        gasPrices.fast = Number(json.fast)
+      }
+    } else {
+      throw Error('Fetch gasPrice failed')
+    }
+    setTimeout(() => fetchGasPrice({ gasPrices, oracleIndex }), 15000)
+  } catch (e) {
+    setTimeout(() => fetchGasPrice({ gasPrices, oracleIndex }), 15000)
+  }
+}
+
+function isValidProof(proof) {
+  // validator expects `websnarkUtils.toSolidityInput(proof)` output
+
+  if (!(proof.pi_a && proof.pi_b && proof.pi_c && proof.publicSignals)) {
+    return { valid: false, reason: 'One of inputs is empty. There must be pi_a, pi_b, pi_c and publicSignals' }
+  }
+
+  Object.keys(proof).forEach(key => {
+    if (!Array.isArray(proof[key])) {
+      return { valid: false, reason: `Corrupted ${key}` }
+    }
+    if (key === 'pi_b') {
+      if (!Array.isArray(proof[key][0]) || !Array.isArray(proof[key][1])) {
+        return { valid: false, reason: `Corrupted ${key}` }
+      }
+    }
+  })
+
+  if (proof.pi_a.length !== 2) {
+    return { valid: false, reason: 'Corrupted pi_a' }
+  }
+
+  if (proof.pi_b.length !== 2 || proof.pi_b[0].length !== 2 || proof.pi_b[1].length !== 2) {
+    return { valid: false, reason: 'Corrupted pi_b' }
+  }
+
+  if (proof.pi_c.length !== 2) {
+    return { valid: false, reason: 'Corrupted pi_c' }
+  }
+
+  if (proof.publicSignals.length !== 4) {
+    return { valid: false, reason: 'Corrupted publicSignals' }
+  }
+
+  for (let [key, input] of Object.entries(proof)) {
+    if (key === 'pi_b') {
+      input = input[0].concat(input[1])
+    }
+
+    for (let i = 0; i < input.length; i++ ) {
+      if (!isHexStrict(input[i]) || input[i].length !== 66) {
+        return { valid: false, reason: `Corrupted ${key}` }
+      }
+    }
+  }
+  return { valid: true }
+}
+
+module.exports = { fetchGasPrice, isValidProof }