restore auth credential from wallet if existed (#224)

* get auth credential from wallet if existed

Author: volodymyr-basiuk

src/credentials/credential-wallet.ts

@@ -192,7 +192,7 @@ export class CredentialWallet implements ICredentialWallet {
     });
 
     if (!authBJJCredsOfIssuer.length) {
-      throw new Error('no auth credentials found');
+      throw new Error(VerifiableConstants.ERRORS.NO_AUTH_CRED_FOUND);
     }
 
     for (let index = 0; index < authBJJCredsOfIssuer.length; index++) {

src/identity/identity-wallet.ts

@@ -626,6 +626,36 @@ export class IdentityWallet implements IIdentityWallet {
       rootOfRoots: ZERO_HASH
     };
 
+    const identity = await this._storage.identity.getIdentity(did.string());
+    if (!identity) {
+      await this._storage.identity.saveIdentity({
+        did: did.string(),
+        state: currentState,
+        isStatePublished: false,
+        isStateGenesis: true
+      });
+    }
+
+    // check whether we have auth credential, if not - create a new one
+    const credentials = await this._credentialWallet.findByQuery({
+      credentialSubject: {
+        x: {
+          $eq: pubKey.p[0].toString()
+        },
+        y: {
+          $eq: pubKey.p[1].toString()
+        }
+      },
+      allowedIssuers: [did.string()]
+    });
+
+    if (credentials.length) {
+      return {
+        did,
+        credential: credentials[0]
+      };
+    }
+
     const credential = await this.createAuthBJJCredential(
       did,
       pubKey,
@@ -658,13 +688,6 @@ export class IdentityWallet implements IIdentityWallet {
       onChain: opts.revocationOpts.onChain
     });
 
-    await this._storage.identity.saveIdentity({
-      did: did.string(),
-      state: currentState,
-      isStatePublished: false,
-      isStateGenesis: true
-    });
-
     await this._credentialWallet.save(credential);
 
     return {
@@ -1042,7 +1065,7 @@ export class IdentityWallet implements IIdentityWallet {
       }
     }
 
-    throw new Error('no auth credentials found');
+    throw new Error(VerifiableConstants.ERRORS.NO_AUTH_CRED_FOUND);
   }
 
   /** {@inheritDoc IIdentityWallet.revokeCredential} */

src/verifiable/constants.ts

@@ -4,7 +4,8 @@ export const VerifiableConstants = Object.freeze({
     FiELD_IS_EMPTY: 'fieldPath is empty',
     CONTEXT_TYPE_IS_EMPTY: 'ctxType is empty',
     // ErrStateNotFound issuer state is genesis state.
-    IDENTITY_DOES_NOT_EXIST: 'Identity does not exist'
+    IDENTITY_DOES_NOT_EXIST: 'Identity does not exist',
+    NO_AUTH_CRED_FOUND: 'no auth credentials found'
   },
   CREDENTIAL_TYPE: {
     // VerifiableCredential is a W3C verifiable credential type

tests/handlers/auth.test.ts

@@ -40,7 +40,8 @@ import {
   Sec256k1Provider,
   StateInfo,
   hexToBytes,
-  NativeProver
+  NativeProver,
+  VerifiableConstants
 } from '../../src';
 import { Token } from '@iden3/js-jwz';
 import { Blockchain, DID, DidMethod, NetworkId } from '@iden3/js-iden3-core';
@@ -2223,12 +2224,12 @@ describe('auth', () => {
 
     // check that we don't have auth credentials now
     await expect(idWallet.getActualAuthCredential(issuerDID)).to.rejectedWith(
-      'no auth credentials found'
+      VerifiableConstants.ERRORS.NO_AUTH_CRED_FOUND
     );
 
     // check that we can't issue new credential
     await expect(idWallet.issueCredential(issuerDID, claimReq)).to.rejectedWith(
-      'no auth credentials found'
+      VerifiableConstants.ERRORS.NO_AUTH_CRED_FOUND
     );
 
     // this should this work because we haven't revoked user keys
@@ -2258,7 +2259,7 @@ describe('auth', () => {
 
     // this should not work because we revoked user keys
     await expect(handleAuthorizationRequest(userDID, authReqBody)).to.rejectedWith(
-      'no auth credentials found'
+      VerifiableConstants.ERRORS.NO_AUTH_CRED_FOUND
     );
   });
 });

tests/identity/id.test.ts

@@ -28,6 +28,7 @@ import {
 } from '../helpers';
 import { expect } from 'chai';
 import { Wallet } from 'ethers';
+import { getRandomBytes } from '@iden3/js-crypto';
 
 describe('identity', () => {
   let credWallet: ICredentialWallet;
@@ -318,4 +319,16 @@ describe('identity', () => {
     const afterRevokeProofNRcredential2 = await idWallet.generateNonRevocationMtp(did, credential2);
     expect(afterRevokeProofNRcredential2.proof.existence).to.equal(false);
   });
+
+  it("restore identity (doesn't create a new auth BJJ credential)", async () => {
+    const seed = getRandomBytes(32);
+    const { did, credential } = await createIdentity(idWallet, { seed });
+
+    // "restore" identity from the same seed
+    const { did: restoredDid, credential: restoredCredential } = await createIdentity(idWallet, {
+      seed
+    });
+    expect(credential).to.be.deep.eq(restoredCredential);
+    expect(did.string()).to.be.eq(restoredDid.string());
+  });
 });