INTERNAL PR js-iden3-auth: VidosResolver

package.json

@@ -66,6 +66,7 @@
     "tsc-alias": "^1.8.8",
     "tsconfig-paths": "^3.14.2",
     "typechain": "^8.1.1",
-    "typescript": "^4.3.5"
+    "typescript": "^4.3.5",
+    "did-resolver": "4.1.0"
   }
 }

src/index.ts

@@ -1,4 +1,5 @@
 export * as auth from '@lib/auth/auth';
 export * as resolver from '@lib/state/resolver';
+export { default as VidosResolver } from '@lib/state/vidosResolver';
 export * as protocol from '@lib/types-sdk';
 export { core } from '@0xpolygonid/js-sdk';

src/state/vidosResolver.ts

@@ -0,0 +1,133 @@
+/* eslint-disable prettier/prettier */
+import { Id } from '@iden3/js-iden3-core';
+import { type IStateResolver, type ResolvedState, isGenesisStateId } from './resolver';
+import type { DIDDocument, DIDResolutionResult, VerificationMethod } from 'did-resolver';
+
+/**
+ * Extended DID resolution result that includes additional information about Polygon ID resolution.
+ */
+type PolygonDidResolutionResult = DIDResolutionResult & {
+  didDocument: DIDDocument & {
+    verificationMethod: (VerificationMethod & {
+      info: {
+        id: string;
+        state: string;
+        replacedByState: string;
+        createdAtTimestamp: string;
+        replacedAtTimestamp: string;
+        createdAtBlock: string;
+        replacedAtBlock: string;
+      };
+      global: {
+        root: string;
+        replacedByRoot: string;
+        createdAtTimestamp: string;
+        replacedAtTimestamp: string;
+        createdAtBlock: string;
+        replacedAtBlock: string;
+      };
+    })[];
+  };
+};
+
+/**
+ * Implementation of {@link IStateResolver} that uses Vidos resolver service to resolve states.
+ * It can serve as drop-in replacement for EthStateResolver.
+ */
+export default class VidosResolver implements IStateResolver {
+  constructor(private readonly resolverUrl: string, private readonly apiKey: string, private readonly network: 'main' | 'mumbai' | 'amoy' = 'main') {}
+
+  // Note: implementation closely resembles EthStateResolver because Vidos resolver internally uses the same contract.
+  // The only difference is the usage of regular HTTP requests instead of web3 calls.
+
+  async rootResolve(state: bigint): Promise<ResolvedState> {
+    const stateHex = state.toString(16);
+
+    const zeroAddress = '11111111111111111111'; // 1 is 0 in base58
+    const did = `did:polygonid:polygon:${this.network}:${zeroAddress}?gist=${stateHex}`;
+
+    const response = await fetch(`${this.resolverUrl}/${encodeURIComponent(did)}`, {
+      method: 'GET',
+      headers: {
+        Authorization: `Bearer ${this.apiKey}`
+      }
+    });
+    const result = (await response.json()) as PolygonDidResolutionResult;
+    if (result.didResolutionMetadata.error) {
+      throw new Error(`error resolving DID: ${result.didResolutionMetadata.error}`);
+    }
+
+    const globalInfo = result.didDocument.verificationMethod[0].global;
+    if (globalInfo == null) throw new Error('gist info not found');
+
+    if (globalInfo.root !== stateHex) {
+      throw new Error('gist info contains invalid state');
+    }
+
+    if (globalInfo.replacedByRoot !== '0') {
+      if (globalInfo.replacedAtTimestamp === '0') {
+        throw new Error('state was replaced, but replaced time unknown');
+      }
+      return {
+        latest: false,
+        state: state,
+        transitionTimestamp: globalInfo.replacedAtTimestamp,
+        genesis: false
+      };
+    }
+
+    return {
+      latest: true,
+      state: state,
+      transitionTimestamp: 0,
+      genesis: false
+    };
+  }
+
+  async resolve(id: bigint, state: bigint): Promise<ResolvedState> {
+    const iden3Id = Id.fromBigInt(id);
+    const stateHex = state.toString(16);
+
+    const did = `did:polygonid:polygon:${this.network}:${iden3Id.string()}`;
+
+    const didWithState = `${did}?state=${stateHex}`;
+    const response = await fetch(`${this.resolverUrl}/${encodeURIComponent(didWithState)}`, {
+      method: 'GET',
+      headers: {
+        Authorization: `Bearer ${this.apiKey}`
+      }
+    });
+    const result = (await response.json()) as PolygonDidResolutionResult;
+    if (result.didResolutionMetadata.error) {
+      throw new Error(`error resolving DID: ${result.didResolutionMetadata.error}`);
+    }
+
+    const isGenesis = isGenesisStateId(id, state);
+
+    const stateInfo = result.didDocument.verificationMethod[0].info;
+    if (stateInfo == null) throw new Error('state info not found');
+
+    if (stateInfo.id !== did) {
+      throw new Error(`state was recorded for another identity`);
+    }
+
+    if (stateInfo.state !== stateHex) {
+      if (stateInfo.replacedAtTimestamp === '0') {
+        throw new Error(`no information about state transition`);
+      }
+      return {
+        latest: false,
+        genesis: false,
+        state: state,
+        transitionTimestamp: Number.parseInt(stateInfo.replacedAtTimestamp)
+      };
+    }
+
+    return {
+      latest: stateInfo.replacedAtTimestamp === '0',
+      genesis: isGenesis,
+      state,
+      transitionTimestamp: Number.parseInt(stateInfo.replacedAtTimestamp)
+    };
+  }
+}