rullst-connect 7.0.0

OAuth2 Social Login for Rust web frameworks.
Documentation
use crate::client::HttpClientExt;
use crate::provider::Provider;
use crate::user::ConnectUser;
use async_trait::async_trait;
use serde_json::Value;
use tokio::sync::OnceCell;

static DEFAULT_CLIENT: ::std::sync::LazyLock<::std::sync::Arc<dyn crate::client::HttpClient>> =
    ::std::sync::LazyLock::new(|| ::std::sync::Arc::new(crate::client::ReqwestClient::new()));

pub struct GoogleProvider {
    pub(crate) client_id: String,
    pub(crate) client_secret: String,
    pub(crate) redirect_url: String,
    pub(crate) http_client: ::std::sync::Arc<dyn crate::client::HttpClient>,
    pub(crate) scopes: Vec<String>,
    pub(crate) state: Option<String>,
    pub(crate) pkce_challenge: Option<String>,
    pub(crate) jwks: OnceCell<jsonwebtoken::jwk::JwkSet>,
}

impl GoogleProvider {
    pub fn new(client_id: String, client_secret: String, redirect_url: String) -> Self {
        debug_assert!(
            !client_id.is_empty(),
            "Socialite Error: client_id cannot be empty"
        );
        debug_assert!(
            !client_secret.is_empty(),
            "Socialite Error: client_secret cannot be empty"
        );
        debug_assert!(
            redirect_url.starts_with("http"),
            "Socialite Error: redirect_url must be a valid HTTP/HTTPS URL"
        );

        Self {
            client_id,
            client_secret,
            redirect_url,
            http_client: DEFAULT_CLIENT.clone(),
            scopes: vec![
                "openid".to_string(),
                "profile".to_string(),
                "email".to_string(),
            ],
            state: None,
            pkce_challenge: None,
            jwks: OnceCell::new(),
        }
    }

    pub fn with_scopes(mut self, scopes: &[&str]) -> Self {
        self.scopes = scopes.iter().map(|s| s.to_string()).collect();
        self
    }

    pub fn with_state(mut self, state: &str) -> Self {
        self.state = Some(state.to_string());
        self
    }

    pub fn with_pkce(mut self, challenge: &str) -> Self {
        self.pkce_challenge = Some(challenge.to_string());
        self
    }

    pub fn with_http_client(
        mut self,
        client: ::std::sync::Arc<dyn crate::client::HttpClient>,
    ) -> Self {
        self.http_client = client;
        self
    }

    #[cfg(feature = "retry")]
    pub fn with_retry(mut self, max_retries: u32) -> Self {
        self.http_client =
            ::std::sync::Arc::new(crate::client::ReqwestClient::new_with_retry(max_retries));
        self
    }

    async fn get_jwks(&self) -> Result<&jsonwebtoken::jwk::JwkSet, crate::error::ConnectError> {
        self.jwks
            .get_or_try_init(|| async {
                let res = self
                    .http_client
                    .get("https://www.googleapis.com/oauth2/v3/certs")
                    .send()
                    .await?
                    .error_for_status()?
                    .json::<jsonwebtoken::jwk::JwkSet>()
                    .await?;
                Ok(res)
            })
            .await
    }
}

#[async_trait]
impl Provider for GoogleProvider {
    fn redirect_url(&self) -> String {
        let mut params = crate::provider::build_oauth_params(
            &self.client_id,
            &self.redirect_url,
            &self.scopes,
            self.state.as_deref(),
            self.pkce_challenge.as_deref(),
        );
        format!(
            "https://accounts.google.com/o/oauth2/v2/auth?{}",
            params.finish()
        )
    }

    async fn get_user(&self, auth_code: &str) -> Result<ConnectUser, crate::error::ConnectError> {
        // Exchange code for token
        let token_res = self
            .http_client
            .post(self.token_url())
            .form(&[
                ("client_id", self.client_id.as_str()),
                ("client_secret", self.client_secret.as_str()),
                ("code", auth_code),
                ("grant_type", "authorization_code"),
                ("redirect_uri", self.redirect_url.as_str()),
            ])
            .send()
            .await?
            .error_for_status()?
            .json::<Value>()
            .await?;

        let access_token = token_res["access_token"].as_str().ok_or_else(|| {
            crate::error::ConnectError::Token("Failed to get access_token".to_string())
        })?;

        let mut user = if let Some(id_token) = token_res["id_token"].as_str() {
            // Secure OIDC: Verify the signature of Google's id_token
            let mut payload: Option<Value> = None;
            if let Ok(header) = jsonwebtoken::decode_header(id_token) {
                let kid = header.kid.unwrap_or_default();
                if let Ok(jwks) = self.get_jwks().await
                    && let Some(jwk) = jwks.find(&kid)
                    && let Ok(decoding_key) = jsonwebtoken::DecodingKey::from_jwk(jwk)
                {
                    let mut validation = jsonwebtoken::Validation::new(header.alg);
                    validation.set_audience(&[&self.client_id]);
                    validation.set_issuer(&["https://accounts.google.com", "accounts.google.com"]);
                    validation.validate_exp = true;

                    if let Ok(token_data) =
                        jsonwebtoken::decode::<Value>(id_token, &decoding_key, &validation)
                    {
                        payload = Some(token_data.claims);
                    }
                }
            }

            if let Some(p) = payload {
                ConnectUser {
                    id: p["sub"].as_str().map(String::from).unwrap_or_default(),
                    name: p["name"].as_str().map(String::from).unwrap_or_default(),
                    email: p["email"].as_str().map(|s: &str| s.to_string()),
                    avatar_url: p["picture"]
                        .as_str()
                        .map(|s: &str| s.replace("=s96-c", "=s400-c")),
                    email_verified: p["email_verified"].as_bool(),
                    raw_data: p,
                    access_token: access_token.to_string(),
                    refresh_token: None,
                    expires_in: None,
                }
            } else {
                // If signature validation fails, log & fallback to secure /userinfo endpoint
                tracing::warn!(
                    "Google id_token validation failed, falling back to secure userinfo request"
                );
                self.get_user_from_token(access_token).await?
            }
        } else {
            self.get_user_from_token(access_token).await?
        };

        user.refresh_token = token_res["refresh_token"]
            .as_str()
            .map(|s: &str| s.to_string());
        user.expires_in = token_res["expires_in"]
            .as_u64()
            .or_else(|| token_res["expires_in"].as_i64().map(|v| v as u64));
        Ok(user)
    }

    async fn get_user_from_token(
        &self,
        access_token: &str,
    ) -> Result<ConnectUser, crate::error::ConnectError> {
        // Fetch user profile
        let user_res = self
            .http_client
            .get("https://www.googleapis.com/oauth2/v3/userinfo")
            .header("Authorization", format!("Bearer {}", access_token))
            .send()
            .await?
            .error_for_status()?
            .json::<Value>()
            .await?;

        Ok(ConnectUser {
            id: user_res["sub"]
                .as_str()
                .map(String::from)
                .unwrap_or_default(),
            name: user_res["name"]
                .as_str()
                .map(String::from)
                .unwrap_or_default(),
            email: user_res["email"].as_str().map(|s: &str| s.to_string()),
            avatar_url: user_res["picture"]
                .as_str()
                .map(|s: &str| s.replace("=s96-c", "=s400-c")),
            email_verified: user_res["email_verified"].as_bool(),
            raw_data: user_res,
            access_token: access_token.to_string(),
            refresh_token: None,
            expires_in: None,
        })
    }

    async fn revoke_token(&self, token: &str) -> Result<(), crate::error::ConnectError> {
        self.http_client
            .post("https://oauth2.googleapis.com/revoke")
            .form(&[("token", token)])
            .send()
            .await?
            .error_for_status()?;
        Ok(())
    }

    fn token_url(&self) -> String {
        "https://oauth2.googleapis.com/token".to_string()
    }

    async fn refresh_token(
        &self,
        refresh_token: &str,
    ) -> Result<ConnectUser, crate::error::ConnectError> {
        let token_res = self
            .http_client
            .post(self.token_url())
            .form(&[
                ("client_id", self.client_id.as_str()),
                ("client_secret", self.client_secret.as_str()),
                ("refresh_token", refresh_token),
                ("grant_type", "refresh_token"),
            ])
            .send()
            .await?
            .error_for_status()?
            .json::<serde_json::Value>()
            .await?;

        if let Some(err) = token_res["error"].as_str() {
            let err_desc = token_res["error_description"].as_str().unwrap_or_default();
            return Err(crate::error::ConnectError::Token(format!(
                "Provider returned error: {} - {}",
                err, err_desc
            )));
        }

        let access_token = token_res["access_token"].as_str().ok_or_else(|| {
            crate::error::ConnectError::Token(
                "Failed to get access_token during refresh".to_string(),
            )
        })?;

        let mut user = self.get_user_from_token(access_token).await?;
        user.refresh_token = token_res["refresh_token"].as_str().map(|s| s.to_string());
        user.expires_in = token_res["expires_in"]
            .as_u64()
            .or_else(|| token_res["expires_in"].as_i64().map(|v| v as u64));
        Ok(user)
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::provider::Provider;

    #[test]
    fn test_google_redirect_url() {
        let provider = GoogleProvider::new(
            "client_id".to_string(),
            "client_secret".to_string(),
            "https://redirect.url".to_string(),
        );

        let url = provider.redirect_url();
        assert!(url.starts_with("https://accounts.google.com/o/oauth2/v2/auth?"));
        assert!(url.contains("client_id=client_id"));
        assert!(url.contains("redirect_uri=https%3A%2F%2Fredirect.url"));
    }
}