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alibi_plugins/oauth/providers/
paybin.rs

1//! Paybin PKCE grants and decoded ID-token profile bound by its original subject.
2use super::{
3    OAuthAuthorizationPolicy, OAuthProvider, OAuthTokenEndpointAuth, OAuthUserInfo,
4    OAuthUserInfoHandler, OAuthUserInfoRequest, OAuthUserInfoResponse,
5};
6use async_trait::async_trait;
7use base64::Engine;
8use serde_json::Map;
9use serde_json::Value;
10
11/// Application-owned Paybin configuration. Generic signup and asynchronous
12/// user-info/refresh callbacks remain configurable on the returned provider.
13#[derive(Clone)]
14pub struct PaybinOptions {
15    pub client_id: String,
16    pub client_secret: Option<String>,
17    /// Sent only during authorization-code exchange.
18    pub client_key: Option<String>,
19    pub scope: Vec<String>,
20    pub disable_default_scope: bool,
21    pub authorization_endpoint: Option<String>,
22    pub redirect_uri: Option<String>,
23    /// Empty issuers use the published default. Trailing slashes are preserved.
24    pub issuer: Option<String>,
25    pub prompt: Option<String>,
26    /// Receives the original profile before its raw account identity is resolved.
27    pub map_profile_to_user: Option<fn(Value) -> Result<OAuthUserInfo, String>>,
28}
29impl PaybinOptions {
30    #[must_use]
31    pub fn new(client_id: impl Into<String>, client_secret: Option<String>) -> Self {
32        Self {
33            client_id: client_id.into(),
34            client_secret,
35            client_key: None,
36            scope: Vec::new(),
37            disable_default_scope: false,
38            authorization_endpoint: None,
39            redirect_uri: None,
40            issuer: None,
41            prompt: None,
42            map_profile_to_user: None,
43        }
44    }
45}
46impl std::fmt::Debug for PaybinOptions {
47    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
48        formatter
49            .debug_struct("PaybinOptions")
50            .field("client_id", &self.client_id)
51            .field("scope", &self.scope)
52            .field("disable_default_scope", &self.disable_default_scope)
53            .field("authorization_endpoint", &self.authorization_endpoint)
54            .field("redirect_uri", &self.redirect_uri)
55            .finish_non_exhaustive()
56    }
57}
58impl OAuthProvider {
59    #[must_use]
60    pub fn paybin(client_id: &str, client_secret: Option<&str>) -> Self {
61        Self::paybin_with_options(PaybinOptions::new(
62            client_id,
63            client_secret.map(str::to_owned),
64        ))
65    }
66    #[must_use]
67    pub fn paybin_with_options(options: PaybinOptions) -> Self {
68        let secret = options.client_secret.unwrap_or_default();
69        let authentication = if secret.is_empty() {
70            OAuthTokenEndpointAuth::None
71        } else {
72            OAuthTokenEndpointAuth::ClientSecretPost
73        };
74        let issuer = options
75            .issuer
76            .filter(|value| !value.is_empty())
77            .unwrap_or_else(|| "https://idp.paybin.io".into());
78        Self {
79            client_id: options.client_id,
80            client_secret: secret,
81            additional_client_ids: Vec::new(),
82            hosted_domain: None,
83            require_email_verification: false,
84            auth_url: options
85                .authorization_endpoint
86                .filter(|value| !value.is_empty())
87                .unwrap_or_else(|| format!("{issuer}/oauth2/authorize")),
88            token_url: format!("{issuer}/oauth2/token"),
89            user_info_url: None,
90            scopes: vec!["openid".into(), "email".into(), "profile".into()],
91            authorization: Some(OAuthAuthorizationPolicy {
92                preserve_raw_profile_scalars: true,
93                source_profile_exceptions: true,
94                allow_missing_access_token: true,
95                configured_scopes: options.scope,
96                disable_default_scopes: options.disable_default_scope,
97                require_client_id: true,
98                require_client_secret: true,
99                default_prompt: options.prompt,
100                token_endpoint_auth: Some(authentication),
101                authorization_code_client_key: options.client_key,
102                redirect_uri: options.redirect_uri,
103                login_hint: true,
104                propagate_grant_profile_errors: true,
105                preserve_raw_email_errors: true,
106                ..OAuthAuthorizationPolicy::default()
107            }),
108            allowed_request_params: Vec::new(),
109            authorization_params: Vec::new(),
110            account_subject: Some(subject),
111            map_user_info: None,
112            get_user_info: Some(std::sync::Arc::new(PaybinUserInfo {
113                application_mapper: None,
114                mapper: options.map_profile_to_user,
115            })),
116            refresh_access_token: None,
117            verify_id_token: None,
118            id_token: None,
119            disable_id_token_sign_in: false,
120            disable_implicit_sign_up: false,
121            disable_sign_up: false,
122            allow_idp_initiated: false,
123            override_user_info_on_sign_in: false,
124        }
125    }
126}
127#[derive(Clone)]
128struct PaybinUserInfo {
129    application_mapper: Option<std::sync::Arc<dyn super::OAuthProfileMapper>>,
130    mapper: Option<fn(Value) -> Result<OAuthUserInfo, String>>,
131}
132#[async_trait]
133impl OAuthUserInfoHandler for PaybinUserInfo {
134    fn errors_are_exceptions(&self) -> bool {
135        false
136    }
137
138    fn mapped_handler(
139        &self,
140        mapper: std::sync::Arc<dyn super::OAuthProfileMapper>,
141    ) -> Option<std::sync::Arc<dyn OAuthUserInfoHandler>> {
142        let mut handler = self.clone();
143        handler.mapper = None;
144        handler.application_mapper = Some(mapper);
145        Some(std::sync::Arc::new(handler))
146    }
147
148    async fn get_user_info(
149        &self,
150        request: OAuthUserInfoRequest,
151    ) -> Result<OAuthUserInfoResponse, String> {
152        // The pinned factory decodes only. Grant transport and state own admission;
153        // direct ID-token verification is deliberately unsupported.
154        let profile = super::remaining_profile::grant_id_token(&request)?
155            .as_deref()
156            .and_then(decode_profile)
157            .ok_or("Missing or invalid Paybin ID token")?;
158        let application_output = if let Some(mapper) = &self.application_mapper {
159            Some(
160                mapper
161                    .map_profile(profile.clone())
162                    .await
163                    .map_err(super::remaining_profile::profile_exception)?,
164            )
165        } else {
166            None
167        };
168        let mapped = self
169            .mapper
170            .map(|mapper| mapper(profile.clone()))
171            .transpose()
172            .map_err(super::remaining_profile::profile_exception)?;
173        // Keep the published raw JSON independently from typed persistence.
174        let mut output = serde_json::Map::new();
175        for (source, target) in [("email", "email"), ("picture", "image")] {
176            if let Some(value) = profile.get(source) {
177                _ = output.insert(target.into(), value.clone());
178            }
179        }
180        let name = profile
181            .get("name")
182            .filter(|v| truthy(v))
183            .or_else(|| profile.get("preferred_username").filter(|v| truthy(v)))
184            .cloned()
185            .unwrap_or_else(|| Value::String(String::new()));
186        _ = output.insert("name".into(), name.clone());
187        _ = output.insert(
188            "emailVerified".into(),
189            profile
190                .get("email_verified")
191                .filter(|v| truthy(v))
192                .cloned()
193                .unwrap_or(Value::Bool(false)),
194        );
195        if let Some(user) = &mapped {
196            output.extend(user.public_profile(true));
197        }
198        let user_output = Some(output);
199        let user = match mapped {
200            Some(user) => user,
201            None => OAuthUserInfo {
202                additional_fields: Map::default(),
203                id: profile
204                    .get("sub")
205                    .map(super::remaining_profile::js_string)
206                    .transpose()?
207                    .unwrap_or_default(),
208                name: scalar(Some(&name))?,
209                email: profile
210                    .get("email")
211                    .and_then(Value::as_str)
212                    .unwrap_or_default()
213                    .into(),
214                image: scalar(profile.get("picture"))?,
215                email_verified: profile.get("email_verified").is_some_and(truthy),
216            },
217        };
218        let mut response = OAuthUserInfoResponse {
219            user_output,
220            user,
221            data: profile,
222        };
223        if let Some(mapped) = application_output {
224            super::apply_application_mapping(&mut response, mapped)?;
225        }
226        Ok(response)
227    }
228}
229fn truthy(value: &Value) -> bool {
230    match value {
231        Value::Null | Value::Bool(false) => false,
232        Value::Number(value) => value.as_f64() != Some(0.0),
233        Value::String(value) => !value.is_empty(),
234        Value::Array(_) | Value::Object(_) | Value::Bool(true) => true,
235    }
236}
237fn scalar(value: Option<&Value>) -> Result<Option<String>, String> {
238    match value {
239        Some(Value::String(value)) => Ok(Some(value.clone())),
240        Some(Value::Number(value)) => alibi_core::utils::json::number_to_string(value)
241            .map(Some)
242            .map_err(|error| error.to_string()),
243        Some(Value::Bool(value)) => Ok(Some(value.to_string())),
244        None | Some(Value::Null | Value::Array(_) | Value::Object(_)) => Ok(None),
245    }
246}
247fn subject(profile: &Value) -> Result<String, String> {
248    super::remaining_profile::raw_subject(profile.get("sub"))
249}
250
251fn decode_profile(token: &str) -> Option<Value> {
252    let mut parts = token.split('.');
253    _ = parts.next()?;
254    let payload = parts.next()?;
255    _ = parts.next()?;
256    if payload.is_empty() || parts.next().is_some() {
257        return None;
258    }
259    let encoded = payload.replace('-', "+").replace('_', "/");
260    let decoder = base64::engine::GeneralPurpose::new(
261        &base64::alphabet::STANDARD,
262        base64::engine::GeneralPurposeConfig::new()
263            .with_decode_padding_mode(base64::engine::DecodePaddingMode::Indifferent),
264    );
265    let bytes = decoder.decode(encoded).ok()?;
266    let profile: Value = alibi_core::utils::json::from_slice(&bytes).ok()?;
267    profile.is_object().then_some(profile)
268}