[Wallet] Add support for 8 digits verification codes (#5925)

### Description

This PR implements short verification codes. See the demo below.
To enable this feature we need all the validators to support `https`, which is not the case atm, so this feature are disabled by feature flag.

### Short code
Essentially, short code, which user receives consist of two parts: prefix and security code (e.g. `12345678`: `1` - prefix, `2345678` - security code).

We use prefix to identify which issuer has sent the code. Because we can not store persistent mapping of prefix<>issuer on the client side (will be gone after reinstall), we are doing the following:
* Set prefix to issuer's address mod 10 ([0,9]) and pass it with reveal request.
* When we receive a short code with a prefix back, we create a list of validators which map to the same prefix.
* We send security code to obtain attestation code to all issuers from the previous step
* One of them should return a full attestation code, all others should fail.

This approach allows us to scale for more than 10 actionable attestations at the same time and to avoid changing `Attestation.sol` contract to store mapping prefix<>issuer in it.

#### Caveat
We do occasionally redundant requests with security code to wrong validators and those exposing the code itself and increasing waiting time for the user. For 3 SMSs the probability of this happening is 30%.

For more information see this discussion https://discord.com/channels/600834479145353243/732977310101405736/778336853505081344
### Demo
![screen-20201119-212100~2](https://user-images.githubusercontent.com/6160124/99726972-426faf80-2af2-11eb-97b4-0909b8ded3ac.gif)

### Tested

With short codes enabled/disabled.

### Related issues

- Fixes #5384
- Fixes #5394

### Backwards compatibility

Yes

packages/celotool/src/lib/attestation.ts

@@ -2,18 +2,25 @@ import { Address, CeloTransactionParams, ContractKit, OdisUtils } from '@celo/co
 import { AuthSigner } from '@celo/contractkit/lib/identity/odis/query'
 import {
   ActionableAttestation,
-  AttestationsWrapper
+  AttestationsWrapper,
 } from '@celo/contractkit/lib/wrappers/Attestations'
 import { AttestationUtils, PhoneNumberUtils } from '@celo/utils'
 import { concurrentMap } from '@celo/utils/lib/async'
+import { AttestationRequest } from '@celo/utils/lib/io'
 import { sample } from 'lodash'
 import moment from 'moment'
 import { Twilio } from 'twilio'
 
 const DUMMY_SMS_URL = 'https://enzyutth0wxme.x.pipedream.net/'
 
 // Use the supplied salt, or if none supplied, go to ODIS and retrieve a pepper
-export async function getIdentifierAndPepper(kit : ContractKit, context : string, account : string, phoneNumber : string, salt : string | null) {
+export async function getIdentifierAndPepper(
+  kit: ContractKit,
+  context: string,
+  account: string,
+  phoneNumber: string,
+  salt: string | null
+) {
   if (salt) {
     return {
       pepper: salt,
@@ -47,15 +54,18 @@ export async function requestMoreAttestations(
   txParams: CeloTransactionParams = {}
 ) {
   const unselectedRequest = await attestations.getUnselectedRequest(phoneNumber, account)
-  if (unselectedRequest.blockNumber === 0 || (await attestations.isAttestationExpired(unselectedRequest.blockNumber))) {
+  if (
+    unselectedRequest.blockNumber === 0 ||
+    (await attestations.isAttestationExpired(unselectedRequest.blockNumber))
+  ) {
     await attestations
       .approveAttestationFee(attestationsRequested)
       .then((txo) => txo.sendAndWaitForReceipt(txParams))
     await attestations
       .request(phoneNumber, attestationsRequested)
       .then((txo) => txo.sendAndWaitForReceipt(txParams))
   }
-  
+
   const selectIssuers = await attestations.selectIssuersAfterWait(phoneNumber, account)
   await selectIssuers.sendAndWaitForReceipt(txParams)
 }
@@ -70,16 +80,22 @@ export async function requestAttestationsFromIssuers(
   attestations: AttestationsWrapper,
   phoneNumber: string,
   account: string,
-  pepper: string,
+  pepper: string
 ): Promise<RequestAttestationError[]> {
   return concurrentMap(5, attestationsToReveal, async (attestation) => {
     try {
-      const response = await attestations.revealPhoneNumberToIssuer(
-        phoneNumber,
+      const revealRequest: AttestationRequest = {
         account,
-        attestation.issuer,
+        issuer: account,
+        phoneNumber,
+        salt: pepper,
+        smsRetrieverAppSig: undefined,
+        securityCodePrefix: undefined,
+        language: undefined,
+      }
+      const response = await attestations.revealPhoneNumberToIssuer(
         attestation.attestationServiceURL,
-        pepper
+        revealRequest
       )
       if (!response.ok) {
         return {
@@ -192,7 +208,7 @@ export async function chooseFromAvailablePhoneNumbers(
   attestations: AttestationsWrapper,
   twilioClient: Twilio,
   maximumNumberOfAttestations: number,
-  salt: string,
+  salt: string
 ) {
   const availableNumbers = (await twilioClient.incomingPhoneNumbers.list()).filter(
     (number) => number.smsUrl === DUMMY_SMS_URL
@@ -214,7 +230,7 @@ async function findSuitableNumber(
   attestations: AttestationsWrapper,
   numbers: string[],
   maximumNumberOfAttestations: number,
-  salt: string,
+  salt: string
 ) {
   const attestedAccountsLookup = await attestations.lookupIdentifiers(
     numbers.map((n) => PhoneNumberUtils.getPhoneHash(n, salt))
@@ -249,8 +265,7 @@ export async function createPhoneNumber(
     let numbers
     try {
       numbers = await context.mobile.list({ limit: 100 })
-    }
-    catch {
+    } catch {
       // Some geos inc US appear to have no 'mobile' subcategory.
       numbers = await context.local.list({ limit: 100 })
     }

packages/contractkit/src/wrappers/Attestations.test.ts

@@ -1,7 +1,7 @@
 import { testWithGanache } from '@celo/dev-utils/lib/ganache-test'
 import { PhoneNumberUtils } from '@celo/utils'
 import { newKitFromWeb3 } from '../kit'
-import { AttestationsWrapper } from './Attestations'
+import { AttestationsWrapper, getSecurityCodePrefix } from './Attestations'
 
 testWithGanache('Attestations Wrapper', (web3) => {
   const PHONE_NUMBER = '+15555555555'
@@ -54,3 +54,11 @@ testWithGanache('Attestations Wrapper', (web3) => {
     })
   })
 })
+
+describe(getSecurityCodePrefix, () => {
+  it('should compute correct hash', () => {
+    expect(getSecurityCodePrefix('0x000000000000000000000008')).toEqual('8')
+    // 0xf7f551752A78Ce650385B58364225e5ec18D96cB -> 1415591498931780605110544902041322891412830525131
+    expect(getSecurityCodePrefix('0xf7f551752A78Ce650385B58364225e5ec18D96cB')).toEqual('1')
+  })
+})

packages/contractkit/src/wrappers/Attestations.ts

@@ -4,6 +4,7 @@ import { notEmpty, zip3 } from '@celo/base/lib/collections'
 import { parseSolidityStringArray } from '@celo/base/lib/parsing'
 import { appendPath } from '@celo/base/lib/string'
 import { AttestationUtils, SignatureUtils } from '@celo/utils/lib'
+import { AttestationRequest, GetAttestationRequest } from '@celo/utils/lib/io'
 import BigNumber from 'bignumber.js'
 import fetch from 'cross-fetch'
 import { Address, CeloContract, NULL_ADDRESS } from '../base'
@@ -20,6 +21,14 @@ import {
 } from './BaseWrapper'
 import { Validator } from './Validators'
 
+function hashAddressToSingleDigit(address: Address): number {
+  return new BigNumber(address.toLowerCase()).modulo(10).toNumber()
+}
+
+export function getSecurityCodePrefix(issuerAddress: Address) {
+  return `${hashAddressToSingleDigit(issuerAddress)}`
+}
+
 export interface AttestationStat {
   completed: number
   total: number
@@ -59,16 +68,6 @@ type AttestationServiceRunningCheckResult =
   | { isValid: true; result: ActionableAttestation }
   | { isValid: false; issuer: Address }
 
-export interface AttesationServiceRevealRequest {
-  account: Address
-  phoneNumber: string
-  issuer: string
-  // TODO rename to pepper here and in Attesation Service
-  salt?: string
-  smsRetrieverAppSig?: string
-  language?: string
-}
-
 export interface UnselectedRequest {
   blockNumber: number
   attestationsRequested: number
@@ -525,34 +524,16 @@ export class AttestationsWrapper extends BaseWrapper<Attestations> {
 
   /**
    * Reveal phone number to issuer
-   * @param phoneNumber: attestation's phone number
-   * @param account: attestation's account
-   * @param issuer: validator's address
    * @param serviceURL: validator's attestation service URL
-   * @param pepper: phone number privacy pepper
-   * @param smsRetrieverAppSig?: Android app's hash
+   * @param body
    */
-  revealPhoneNumberToIssuer(
-    phoneNumber: string,
-    account: Address,
-    issuer: Address,
-    serviceURL: string,
-    pepper?: string,
-    smsRetrieverAppSig?: string
-  ) {
-    const body: AttesationServiceRevealRequest = {
-      account,
-      phoneNumber,
-      issuer,
-      salt: pepper,
-      smsRetrieverAppSig,
-    }
+  revealPhoneNumberToIssuer(serviceURL: string, requestBody: AttestationRequest) {
     return fetch(appendPath(serviceURL, 'attestations'), {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json',
       },
-      body: JSON.stringify(body),
+      body: JSON.stringify(requestBody),
     })
   }
 
@@ -583,6 +564,29 @@ export class AttestationsWrapper extends BaseWrapper<Attestations> {
     })
   }
 
+  /**
+   * Returns attestation code for provided security code from validator's attestation service
+   * @param serviceURL: validator's attestation service URL
+   * @param body
+   */
+  getAttestationForSecurityCode(serviceURL: string, requestBody: GetAttestationRequest) {
+    const urlParams = new URLSearchParams({
+      phoneNumber: requestBody.phoneNumber,
+      account: requestBody.account,
+      issuer: requestBody.issuer,
+    })
+    if (requestBody.salt) {
+      urlParams.set('salt', requestBody.salt)
+    }
+    if (requestBody.securityCode) {
+      urlParams.set('securityCode', requestBody.securityCode)
+    }
+    return fetch(appendPath(serviceURL, 'get_attestations') + '?' + urlParams, {
+      method: 'GET',
+      headers: { 'Content-Type': 'application/json' },
+    })
+  }
+
   /**
    * Validates a given code by the issuer on-chain
    * @param identifier Attestation identifier (e.g. phone hash)

packages/docs/SUMMARY.md

@@ -262,7 +262,6 @@
     - [AttestationState](developer-resources/contractkit/reference/enums/_wrappers_attestations_.attestationstate.md)
     - [AttestationsWrapper](developer-resources/contractkit/reference/classes/_wrappers_attestations_.attestationswrapper.md)
     - [ActionableAttestation](developer-resources/contractkit/reference/interfaces/_wrappers_attestations_.actionableattestation.md)
-    - [AttesationServiceRevealRequest](developer-resources/contractkit/reference/interfaces/_wrappers_attestations_.attesationservicerevealrequest.md)
     - [AttestationServiceStatusResponse](developer-resources/contractkit/reference/interfaces/_wrappers_attestations_.attestationservicestatusresponse.md)
     - [AttestationStat](developer-resources/contractkit/reference/interfaces/_wrappers_attestations_.attestationstat.md)
     - [AttestationStateForIssuer](developer-resources/contractkit/reference/interfaces/_wrappers_attestations_.attestationstateforissuer.md)
@@ -485,7 +484,6 @@
     - [UnlockableWallet](developer-resources/contractkit/reference/interfaces/_wallets_wallet_.unlockablewallet.md)
     - [Wallet](developer-resources/contractkit/reference/interfaces/_wallets_wallet_.wallet.md)
     - [ActionableAttestation](developer-resources/contractkit/reference/interfaces/_wrappers_attestations_.actionableattestation.md)
-    - [AttesationServiceRevealRequest](developer-resources/contractkit/reference/interfaces/_wrappers_attestations_.attesationservicerevealrequest.md)
     - [AttestationServiceStatusResponse](developer-resources/contractkit/reference/interfaces/_wrappers_attestations_.attestationservicestatusresponse.md)
     - [AttestationStat](developer-resources/contractkit/reference/interfaces/_wrappers_attestations_.attestationstat.md)
     - [AttestationStateForIssuer](developer-resources/contractkit/reference/interfaces/_wrappers_attestations_.attestationstateforissuer.md)