Proper validation of entryway op in account creation (bluesky-social#…

…1975)

* ensure entryway plc rotation key

* update plc lib on pds, test

packages/pds/package.json

@@ -43,7 +43,7 @@
     "@atproto/syntax": "workspace:^",
     "@atproto/xrpc": "workspace:^",
     "@atproto/xrpc-server": "workspace:^",
-    "@did-plc/lib": "^0.0.1",
+    "@did-plc/lib": "^0.0.4",
     "better-sqlite3": "^7.6.2",
     "bytes": "^3.1.2",
     "compression": "^1.7.4",

packages/pds/src/api/com/atproto/server/createAccount.ts

@@ -2,12 +2,12 @@ import { DidDocument, MINUTE, check } from '@atproto/common'
 import { AtprotoData, ensureAtpDocument } from '@atproto/identity'
 import { InvalidRequestError } from '@atproto/xrpc-server'
 import { ExportableKeypair, Keypair, Secp256k1Keypair } from '@atproto/crypto'
+import * as plc from '@did-plc/lib'
 import disposable from 'disposable-email'
 import {
   baseNormalizeAndValidate,
   normalizeAndValidateHandle,
 } from '../../../../handle'
-import * as plc from '@did-plc/lib'
 import { Server } from '../../../../lexicon'
 import { InputSchema as CreateAccountInput } from '../../../../lexicon/types/com/atproto/server/createAccount'
 import AppContext from '../../../../context'
@@ -101,7 +101,12 @@ const validateInputsForEntrywayPds = async (
       'IncompatibleDidDoc',
     )
   }
-  await plc.assureValidOp(plcOp)
+  try {
+    await plc.assureValidOp(plcOp)
+    await plc.assureValidSig([plcRotationKey], plcOp)
+  } catch (err) {
+    throw new InvalidRequestError('invalid plc operation', 'IncompatibleDidDoc')
+  }
   const doc = plc.formatDidDoc({ did, ...plcOp })
   const data = ensureAtpDocument(doc)
 

packages/pds/tests/entryway.test.ts

@@ -1,5 +1,6 @@
 import * as os from 'node:os'
 import * as path from 'node:path'
+import * as plcLib from '@did-plc/lib'
 import AtpAgent from '@atproto/api'
 import { Secp256k1Keypair, randomStr } from '@atproto/crypto'
 import { SeedClient, TestPds, TestPlc, mockResolvers } from '@atproto/dev-env'
@@ -131,6 +132,28 @@ describe('entryway', () => {
     expect(accountFromPds?.handle).toEqual('alice3.test')
     expect(accountFromEntryway?.handle).toEqual('alice3.test')
   })
+
+  it('does not allow bringing own op to account creation.', async () => {
+    const {
+      data: { signingKey },
+    } = await pdsAgent.api.com.atproto.server.reserveSigningKey({})
+    const rotationKey = await Secp256k1Keypair.create()
+    const plcCreate = await plcLib.createOp({
+      signingKey,
+      rotationKeys: [rotationKey.did(), entryway.ctx.plcRotationKey.did()],
+      handle: 'weirdalice.test',
+      pds: pds.ctx.cfg.service.publicUrl,
+      signer: rotationKey,
+    })
+    const tryCreateAccount = pdsAgent.api.com.atproto.server.createAccount(
+      { did: plcCreate.did, plcOp: plcCreate.op, handle: 'weirdalice.test' },
+      {
+        headers: SeedClient.getHeaders(accessToken),
+        encoding: 'application/json',
+      },
+    )
+    await expect(tryCreateAccount).rejects.toThrow('invalid plc operation')
+  })
 })
 
 const createEntryway = async (