feat: add verify metadata content option

src/types.ts

@@ -24,14 +24,18 @@ export type DecentralandSignatureRequiredContext<P extends {} = {}> = {
   verification: DecentralandSignatureData<P>
 }
 
-export type VerifyAuthChainHeadersOptions = {
+export type VerifyAuthChainHeadersOptions<
+  P extends Record<string, any> = Record<string, any>
+> = {
   catalyst?: string
   expiration?: number
+  verifyMetadataContent?: (authMetadata: P) => boolean
 }
 
 export type SessionOptions = {
   optional?: boolean
   onError?: (err: RequestError) => any
 }
 
-export type Options = VerifyAuthChainHeadersOptions & SessionOptions
+export type Options<P extends Record<string, any> = Record<string, any>> =
+  VerifyAuthChainHeadersOptions<P> & SessionOptions

src/verify.test.ts

@@ -7,11 +7,13 @@ import {
   AUTH_TIMESTAMP_HEADER,
   DEFAULT_EXPIRATION,
 } from './types'
+
 import verifyAuthChainHeaders, {
   isEIP1664AuthChain,
   verifyEIP1654Sign,
   verifyPersonalSign,
 } from './verify'
+import RequestError from './errors'
 
 const identity: AuthIdentity = {
   ephemeralIdentity: {
@@ -262,5 +264,74 @@ describe(`src/verifyAuthChainHeaders`, () => {
         verifyAuthChainHeaders(method, path, headers)
       ).rejects.toThrowError('Invalid signature:')
     })
+
+    describe('when verifyMetadataContent function is defined', () => {
+      describe('and the verification returns true', () => {
+        test('should return all the information about a header signature', async () => {
+          const timestamp = Date.now()
+          const metadata = { signer: 'a signer' }
+          const method = 'get'
+          const path = '/path/to/resource'
+          const payload = [method, path, timestamp, JSON.stringify(metadata)]
+            .join(':')
+            .toLowerCase()
+          const chain = Authenticator.signPayload(identity, payload)
+          const headers = createAuthChainHeaders(chain, timestamp, metadata)
+          const options = { verifyMetadataContent: () => true }
+
+          expect(
+            await verifyAuthChainHeaders(method, path, headers, options)
+          ).toEqual({
+            auth: identity.authChain[0].payload.toLowerCase(),
+            authMetadata: metadata,
+          })
+        })
+      })
+
+      describe('and the verification returns false', () => {
+        test('should throw an error indicating the metadata is invalid', async () => {
+          const timestamp = Date.now()
+          const metadata = { signer: 'a signer' }
+          const method = 'get'
+          const path = '/path/to/resource'
+          const payload = [method, path, timestamp, JSON.stringify(metadata)]
+            .join(':')
+            .toLowerCase()
+          const chain = Authenticator.signPayload(identity, payload)
+          const headers = createAuthChainHeaders(chain, timestamp, metadata)
+          const options = { verifyMetadataContent: () => false }
+
+          await expect(() =>
+            verifyAuthChainHeaders(method, path, headers, options)
+          ).rejects.toThrowError(
+            `Invalid metadata content: ${JSON.stringify(metadata)}`
+          )
+        })
+      })
+
+      describe('and the verification throws an error', () => {
+        test('should throw an error indicating the metadata is invalid', async () => {
+          const timestamp = Date.now()
+          const error = 'a custom error'
+          const metadata = { signer: 'a signer' }
+          const method = 'get'
+          const path = '/path/to/resource'
+          const payload = [method, path, timestamp, JSON.stringify(metadata)]
+            .join(':')
+            .toLowerCase()
+          const chain = Authenticator.signPayload(identity, payload)
+          const headers = createAuthChainHeaders(chain, timestamp, metadata)
+          const options = {
+            verifyMetadataContent: () => {
+              throw new RequestError(error, 400)
+            },
+          }
+
+          await expect(() =>
+            verifyAuthChainHeaders(method, path, headers, options)
+          ).rejects.toThrowError(error)
+        })
+      })
+    })
   })
 })

src/verify.ts

@@ -193,6 +193,16 @@ export default async function verify<P extends {} = {}>(
   const ownerAddress = await verifySign(authChain, payload, options)
   await verifyExpiration(timestamp, options)
 
+  if (
+    options.verifyMetadataContent &&
+    !options.verifyMetadataContent(metadata)
+  ) {
+    throw new RequestError(
+      `Invalid metadata content: ${JSON.stringify(metadata)}`,
+      400
+    )
+  }
+
   return {
     auth: ownerAddress,
     authMetadata: metadata as P,