Supabase Gotrue Apple Nonce Hex Vs Base64url Encoding Mismatch

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grant_type=id_token with provider=apple returns "Nonces mismatch"` even when the client sends a correct nonce.

If a Swift app using Supabase Auth + Sign in with Apple gets "Nonces mismatch" on every attempt: 1. nonce` is set on the Apple request 2.

Without a nonce, Apple Sign in with Apple is vulnerable to replay attacks on the id_token within the ~10 minute token validity window. For most apps this is acceptable.

nonce and passes nonce` to OpenIDConnectCredentials produces "Nonces mismatch" because GoTrue's hex-encoded SHA-256 won't match Apple's base64url-encoded SHA-256. This costs you one or two debug rounds before someone finds issue #2378.

How it's structured

  1. The bug POST /auth/v1/token?grant_type=id_token with provider=apple returns "Nonces mismatch" even whe…

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