# AshAuthentication "EdDSA" algorithm not working **URL:** \ **Category:** Questions\ **Tags:** phoenix, ash, ash-authentication\ **Created:** [June 23, 2025, 11:02am UTC](https://forum.elixirforum.com/t/ashauthentication-eddsa-algorithm-not-working/71401 "2025-06-23T11:02:31Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![carla](https://forum.elixirforum.com/letter_avatar_proxy/v4/letter/c/e9c0ed/32.png) [@carla](https://forum.elixirforum.com/u/carla)\ **Post date:** [June 23, 2025, 11:02am UTC](https://forum.elixirforum.com/t/ashauthentication-eddsa-algorithm-not-working/71401/1 "2025-06-23T11:02:31Z")
Hey there 🙂 We started using AshAuthentication to implement SSO with Rauthy as OIDC provider in our dev setup. In Rauthy I can choose “EdDSA” so for my oidc strategy I set `id_token_signed_response_alg "EdDSA` but I het the following error ```elixir [error] ** (FunctionClauseError) no function clause matching in Assent.JWTAdapter.AssentJWT.verify_message/4 ``` Can somebody help me out? Is this an issue with my Rauthy configuration or is anyone else facing the same issue? Choosing RS256 is working fine. Best regards and thanks in advance! ---
**Author:** ![zachdaniel](https://forum.elixirforum.com/user_avatar/forum.elixirforum.com/zachdaniel/32/31980_2.png) [@zachdaniel](https://forum.elixirforum.com/u/zachdaniel)\ **Post date:** [June 23, 2025, 11:43am UTC](https://forum.elixirforum.com/t/ashauthentication-eddsa-algorithm-not-working/71401/2 "2025-06-23T11:43:54Z")
What is the stack trace on the error? ---
**Author:** ![carla](https://forum.elixirforum.com/letter_avatar_proxy/v4/letter/c/e9c0ed/32.png) [@carla](https://forum.elixirforum.com/u/carla)\ **Post date:** [June 23, 2025, 2:13pm UTC](https://forum.elixirforum.com/t/ashauthentication-eddsa-algorithm-not-working/71401/3 "2025-06-23T14:13:54Z")
```elixir [error] ** (FunctionClauseError) no function clause matching in Assent.JWTAdapter.AssentJWT.verify_message/4 (assent 0.2.13) lib/assent/jwt_adapter/assent_jwt.ex:243: Assent.JWTAdapter.AssentJWT.verify_message("eyJhbGciOiJFZERTQSIsImtpZCI6IjJSZkJzR1d2b09xeG1WZTlucXFTODNyTiIsInR5cCI6IkpXVCJ9.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", <<22, 212, 17, 15, 242, 194, 83, 153, 181, 180, 241, 92, 238, 104, 246, 152, 133, 203, 4, 249, 211, 224, 221, 157, 158, 14, 108, 36, 31, 116, 231, 7, 208, 38, 201, 119, 251, 219, 167, 42, 151, 70, 167, 63, 240, 165, 151, 11, 189, 254, ...>>, "EdDSA", %{"alg" => "EdDSA", "crv" => "Ed25519", "kid" => "2RfBsGWvoOqxmVe9nqqS83rN", "kty" => "OKP", "x" => "suXSvDkHWWx686g8EcwrcnCN7SH_0nwDvKqzshvpy3Q"}) (assent 0.2.13) lib/assent/jwt_adapter/assent_jwt.ex:229: Assent.JWTAdapter.AssentJWT.do_verify/5 (assent 0.2.13) lib/assent/jwt_adapter/assent_jwt.ex:149: Assent.JWTAdapter.AssentJWT.verify/3 (assent 0.2.13) lib/assent/strategies/oidc.ex:311: Assent.Strategy.OIDC.validate_id_token/2 (assent 0.2.13) lib/assent/strategies/oidc.ex:279: Assent.Strategy.OIDC.fetch_user/2 (assent 0.2.13) lib/assent/strategies/oauth2.ex:387: Assent.Strategy.OAuth2.fetch_user_with_strategy/3 (ash_authentication 4.9.3) lib/ash_authentication/strategies/oauth2/plug.ex:60: AshAuthentication.Strategy.OAuth2.Plug.callback/2 (ash_authentication 4.9.3) lib/ash_authentication/plug/dispatcher.ex:30: AshAuthentication.Plug.Dispatcher.call/2 (phoenix 1.7.21) lib/phoenix/router/route.ex:42: Phoenix.Router.Route.call/2 (phoenix 1.7.21) lib/phoenix/router.ex:484: Phoenix.Router. __call__ /5 (mv 0.1.0) lib/mv_web/endpoint.ex:1: MvWeb.Endpoint.plug_builder_call/2 (mv 0.1.0) deps/plug/lib/plug/debugger.ex:155: MvWeb.Endpoint."call (overridable 3)"/2 (mv 0.1.0) lib/mv_web/endpoint.ex:1: MvWeb.Endpoint.call/2 (phoenix 1.7.21) lib/phoenix/endpoint/sync_code_reload_plug.ex:22: Phoenix.Endpoint.SyncCodeReloadPlug.do_call/4 (bandit 1.7.0) lib/bandit/pipeline.ex:131: Bandit.Pipeline.call_plug!/2 (bandit 1.7.0) lib/bandit/pipeline.ex:42: Bandit.Pipeline.run/5 (bandit 1.7.0) lib/bandit/http1/handler.ex:13: Bandit.HTTP1.Handler.handle_data/3 (bandit 1.7.0) lib/bandit/delegating_handler.ex:18: Bandit.DelegatingHandler.handle_data/3 (bandit 1.7.0) lib/bandit/delegating_handler.ex:8: Bandit.DelegatingHandler.handle_info/2 (stdlib 6.2.2) gen_server.erl:2345: :gen_server.try_handle_info/3 ``` ---
**Author:** ![zachdaniel](https://forum.elixirforum.com/user_avatar/forum.elixirforum.com/zachdaniel/32/31980_2.png) [@zachdaniel](https://forum.elixirforum.com/u/zachdaniel)\ **Post date:** [June 23, 2025, 6:11pm UTC](https://forum.elixirforum.com/t/ashauthentication-eddsa-algorithm-not-working/71401/4 "2025-06-23T18:11:44Z")
Interesting, it may not be supported by assent: [assent/lib/assent/jwt\_adapter/assent\_jwt.ex at v0.3.1 · pow-auth/assent · GitHub](https://github.com/pow-auth/assent/blob/v0.3.1/lib/assent/jwt_adapter/assent_jwt.ex#L241) @jimsynz knows more about how this all fits together than I do though, I’ll see if he has a few to look. ---
**Author:** ![jimsynz](https://forum.elixirforum.com/user_avatar/forum.elixirforum.com/jimsynz/32/39319_2.png) [@jimsynz](https://forum.elixirforum.com/u/jimsynz)\ **Post date:** [June 23, 2025, 8:59pm UTC](https://forum.elixirforum.com/t/ashauthentication-eddsa-algorithm-not-working/71401/5 "2025-06-23T20:59:23Z")
Yeah, for this stuff we just delegate to assent to do it, so I think opening an issue with them is the way to go. ---
**Author:** ![carla](https://forum.elixirforum.com/letter_avatar_proxy/v4/letter/c/e9c0ed/32.png) [@carla](https://forum.elixirforum.com/u/carla)\ **Post date:** [June 24, 2025, 5:43am UTC](https://forum.elixirforum.com/t/ashauthentication-eddsa-algorithm-not-working/71401/6 "2025-06-24T05:43:51Z")
okay, I will do so! Thanks for your support 🙂 ---
**Author:** ![carla](https://forum.elixirforum.com/letter_avatar_proxy/v4/letter/c/e9c0ed/32.png) [@carla](https://forum.elixirforum.com/u/carla)\ **Post date:** [June 25, 2025, 7:41am UTC](https://forum.elixirforum.com/t/ashauthentication-eddsa-algorithm-not-working/71401/7 "2025-06-25T07:41:57Z")
[https://github.com/pow-auth/assent/issues/193](https://github.com/pow-auth/assent/issues/193)