fix: properly manage RFC 3986 authority domain check (#2351)

* fix: properly manage `RFC 3986 authority domain` check

## PR overview
Using the current regex expression only second level domains are accepted. However, that is not the way it is specified on RFC 3986.

With the current implementation for instance all country code second-level domains (ccSLD) like domain.co.uk are not accepted.

The fix allows multi-level domains.

### Detailed summary
Changed `domainRegex` regex to allow multiple level domains.

* Create rfc3986-authority-domain.md

* Fix: Replace instead of adding

* Update .changeset/rfc3986-authority-domain.md

Co-authored-by: awkweb <tom@meagher.co>

* test(siwe): sub/multi-level domains

---------

Co-authored-by: awkweb <tom@meagher.co>

.changeset/rfc3986-authority-domain.md

@@ -0,0 +1,5 @@
+---
+"viem": patch
+---
+
+Fixed `createSiweMessage` domain check to be RFC 3986 compliant.

src/utils/siwe/createSiweMessage.test.ts

@@ -32,6 +32,47 @@ test('default', () => {
   vi.useRealTimers()
 })
 
+test('parameters: domain', () => {
+  vi.useFakeTimers()
+  vi.setSystemTime(new Date(Date.UTC(2023, 1, 1)))
+
+  expect(
+    createSiweMessage({
+      ...message,
+      domain: 'foo.example.com',
+    }),
+  ).toMatchInlineSnapshot(`
+    "foo.example.com wants you to sign in with your Ethereum account:
+    0xA0Cf798816D4b9b9866b5330EEa46a18382f251e
+
+
+    URI: https://example.com/path
+    Version: 1
+    Chain ID: 1
+    Nonce: foobarbaz
+    Issued At: 2023-02-01T00:00:00.000Z"
+  `)
+
+  expect(
+    createSiweMessage({
+      ...message,
+      domain: 'example.co.uk',
+    }),
+  ).toMatchInlineSnapshot(`
+    "example.co.uk wants you to sign in with your Ethereum account:
+    0xA0Cf798816D4b9b9866b5330EEa46a18382f251e
+
+
+    URI: https://example.com/path
+    Version: 1
+    Chain ID: 1
+    Nonce: foobarbaz
+    Issued At: 2023-02-01T00:00:00.000Z"
+  `)
+
+  vi.useRealTimers()
+})
+
 test('parameters: scheme', () => {
   vi.useFakeTimers()
   vi.setSystemTime(new Date(Date.UTC(2023, 1, 1)))

src/utils/siwe/createSiweMessage.ts

@@ -170,7 +170,7 @@ export function createSiweMessage(
 }
 
 const domainRegex =
-  /^([a-zA-Z0-9][-a-zA-Z0-9]{0,61}[a-zA-Z0-9])\.[a-zA-Z]{2,}(:[0-9]{1,5})?$/
+  /^([a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}(:[0-9]{1,5})?$/
 const ipRegex =
   /^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(:[0-9]{1,5})?$/
 const localhostRegex = /^localhost(:[0-9]{1,5})?$/