Add custom nonce option instead of always generating a new one if checks: ["nonce"] is set

[0x73696d616f]

Goals

1. Apps may wish to use custom nonces in the jwt id tokens, which at the moment is not possible.

Non-Goals

No response

Background

My use case is inserting custom information in the id token. It's much easier to use the nonce for all providers then setting custom claims for all of them.

Proposal

With package patch, I was able to get it working with the following diffs on next-auth:

diff --git a/node_modules/next-auth/core/lib/oauth/checks.js b/node_modules/next-auth/core/lib/oauth/checks.js
index 70fa576..4d31122 100644
--- a/node_modules/next-auth/core/lib/oauth/checks.js
+++ b/node_modules/next-auth/core/lib/oauth/checks.js
@@ -124,7 +124,7 @@ const nonce = {
 
     if (!((_options$provider$che4 = options.provider.checks) !== null && _options$provider$che4 !== void 0 && _options$provider$che4.includes("nonce"))) return;
 
-    const value = _openidClient.generators.nonce();
+    const value = resParams.nonce || _openidClient.generators.nonce();
 
     resParams.nonce = value;
     const maxAge = (_options$cookies$nonc = options.cookies.nonce.options.maxAge) !== null && _options$cookies$nonc !== void 0 ? _options$cookies$nonc : NONCE_MAX_AGE;
diff --git a/node_modules/next-auth/src/core/lib/oauth/checks.ts b/node_modules/next-auth/src/core/lib/oauth/checks.ts
index f497012..f256b3b 100644
--- a/node_modules/next-auth/src/core/lib/oauth/checks.ts
+++ b/node_modules/next-auth/src/core/lib/oauth/checks.ts
@@ -143,7 +143,7 @@ export const nonce = {
     resParams: AuthorizationParameters
   ) {
     if (!options.provider.checks?.includes("nonce")) return
-    const value = generators.nonce()
+    const value = resParams.nonce || generators.nonce()
     resParams.nonce = value
     const maxAge = options.cookies.nonce.options.maxAge ?? NONCE_MAX_AGE
     cookies.push(await signCookie("nonce", value, maxAge, options))