Supporting service account key format OR user credential formats

src/authentication_manager.rs

@@ -2,9 +2,9 @@ use async_trait::async_trait;
 use tokio::sync::Mutex;
 
 use crate::custom_service_account::CustomServiceAccount;
-use crate::default_authorized_user::ConfigDefaultCredentials;
 use crate::default_service_account::MetadataServiceAccount;
 use crate::error::Error;
+use crate::flexible_credential_source::FlexibleCredentialSource;
 use crate::gcloud_authorized_user::GCloudAuthorizedUser;
 use crate::types::{self, HyperClient, Token};
 
@@ -43,15 +43,25 @@ impl AuthenticationManager {
     #[tracing::instrument]
     pub async fn new() -> Result<Self, Error> {
         tracing::debug!("Initializing gcp_auth");
-        if let Some(service_account) = CustomServiceAccount::from_env()? {
-            return Ok(service_account.into());
+        let client = types::client();
+        if let Some(service_account) = FlexibleCredentialSource::from_env().await? {
+            tracing::debug!("Using GOOGLE_APPLICATION_CREDENTIALS env");
+
+            return Ok(Self {
+                service_account: service_account.try_into_service_account(&client).await?,
+                client,
+                refresh_mutex: Mutex::new(()),
+            });
         }
 
-        let client = types::client();
-        let default_user_error = match ConfigDefaultCredentials::new(&client).await {
+        let default_user_error = match FlexibleCredentialSource::from_default_credentials().await {
             Ok(service_account) => {
                 tracing::debug!("Using ConfigDefaultCredentials");
-                return Ok(Self::build(client, service_account));
+                return Ok(Self {
+                    service_account: service_account.try_into_service_account(&client).await?,
+                    client,
+                    refresh_mutex: Mutex::new(()),
+                });
             }
             Err(e) => e,
         };

src/custom_service_account.rs

@@ -54,7 +54,7 @@ impl CustomServiceAccount {
         }
     }
 
-    fn new(credentials: ApplicationCredentials) -> Result<Self, Error> {
+    pub(crate) fn new(credentials: ApplicationCredentials) -> Result<Self, Error> {
         Ok(Self {
             signer: Signer::new(&credentials.private_key)?,
             credentials,
@@ -137,7 +137,6 @@ impl ServiceAccount for CustomServiceAccount {
 
 #[derive(Serialize, Deserialize, Clone)]
 pub(crate) struct ApplicationCredentials {
-    pub(crate) r#type: Option<String>,
     /// project_id
     pub(crate) project_id: Option<String>,
     /// private_key_id

src/default_authorized_user.rs

@@ -1,4 +1,3 @@
-use std::fs;
 use std::sync::RwLock;
 
 use async_trait::async_trait;
@@ -19,18 +18,11 @@ pub(crate) struct ConfigDefaultCredentials {
 
 impl ConfigDefaultCredentials {
     const DEFAULT_TOKEN_GCP_URI: &'static str = "https://accounts.google.com/o/oauth2/token";
-    const USER_CREDENTIALS_PATH: &'static str =
-        ".config/gcloud/application_default_credentials.json";
-
-    pub(crate) async fn new(client: &HyperClient) -> Result<Self, Error> {
-        tracing::debug!("Loading user credentials file");
-        let mut home = dirs_next::home_dir().ok_or(Error::NoHomeDir)?;
-        home.push(Self::USER_CREDENTIALS_PATH);
-
-        let file = fs::File::open(home).map_err(Error::UserProfilePath)?;
-        let credentials = serde_json::from_reader::<_, UserCredentials>(file)
-            .map_err(Error::UserProfileFormat)?;
 
+    pub(crate) async fn from_user_credentials(
+        credentials: UserCredentials,
+        client: &HyperClient,
+    ) -> Result<Self, Error> {
         Ok(Self {
             token: RwLock::new(Self::get_token(&credentials, client).await?),
             credentials,
@@ -105,7 +97,7 @@ struct RefreshRequest<'a> {
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone)]
-struct UserCredentials {
+pub(crate) struct UserCredentials {
     /// Client id
     pub(crate) client_id: String,
     /// Client secret
@@ -114,8 +106,6 @@ struct UserCredentials {
     pub(crate) quota_project_id: Option<String>,
     /// Refresh Token
     pub(crate) refresh_token: String,
-    /// Type
-    pub(crate) r#type: String,
 }
 
 /// How many times to attempt to fetch a token from the GCP token endpoint.

src/flexible_credential_source.rs

@@ -0,0 +1,195 @@
+use std::path::{Path, PathBuf};
+
+use serde::{Deserialize, Serialize};
+use tokio::fs;
+
+use crate::{
+    authentication_manager::ServiceAccount,
+    custom_service_account::ApplicationCredentials,
+    default_authorized_user::{ConfigDefaultCredentials, UserCredentials},
+    types::HyperClient,
+    CustomServiceAccount, Error,
+};
+
+// Implementation referenced from
+// https://github.com/golang/oauth2/blob/a835fc4358f6852f50c4c5c33fddcd1adade5b0a/google/google.go#L158
+// Currently not implementing external account credentials
+// Currently not implementing impersonating service accounts (coming soon !)
+#[derive(Serialize, Deserialize, Debug)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub(crate) enum FlexibleCredentialSource {
+    // This credential parses the `key.json` file created when running
+    // `gcloud iam service-accounts keys create key.json --iam-account=SA_NAME@PROJECT_ID.iam.gserviceaccount.com`
+    ServiceAccount(ApplicationCredentials),
+    // This credential parses the `~/.config/gcloud/application_default_credentials.json` file
+    // created when running `gcloud auth application-default login`
+    AuthorizedUser(UserCredentials),
+}
+
+impl FlexibleCredentialSource {
+    const USER_CREDENTIALS_PATH: &'static str =
+        ".config/gcloud/application_default_credentials.json";
+
+    pub(crate) async fn from_env() -> Result<Option<Self>, Error> {
+        let creds_path = std::env::var_os("GOOGLE_APPLICATION_CREDENTIALS");
+        if let Some(path) = creds_path {
+            tracing::debug!("Reading credentials file from GOOGLE_APPLICATION_CREDENTIALS env var");
+            let creds = Self::from_file(PathBuf::from(path)).await?;
+            Ok(Some(creds))
+        } else {
+            Ok(None)
+        }
+    }
+
+    pub(crate) async fn from_default_credentials() -> Result<Self, Error> {
+        tracing::debug!("Loading user credentials file");
+        let mut home = dirs_next::home_dir().ok_or(Error::NoHomeDir)?;
+        home.push(Self::USER_CREDENTIALS_PATH);
+        Self::from_file(home).await
+    }
+
+    pub(crate) async fn try_into_service_account(
+        self,
+        client: &HyperClient,
+    ) -> Result<Box<dyn ServiceAccount>, Error> {
+        match self {
+            FlexibleCredentialSource::ServiceAccount(creds) => {
+                let service_account = CustomServiceAccount::new(creds)?;
+                Ok(Box::new(service_account))
+            }
+            FlexibleCredentialSource::AuthorizedUser(creds) => {
+                let service_account =
+                    ConfigDefaultCredentials::from_user_credentials(creds, client).await?;
+                Ok(Box::new(service_account))
+            }
+        }
+    }
+
+    /// Read service account credentials from the given JSON file
+    async fn from_file<T: AsRef<Path>>(path: T) -> Result<Self, Error> {
+        let creds_string = fs::read_to_string(&path)
+            .await
+            .map_err(Error::UserProfilePath)?;
+
+        serde_json::from_str::<FlexibleCredentialSource>(&creds_string)
+            .map_err(Error::CustomServiceAccountCredentials)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{flexible_credential_source::FlexibleCredentialSource, types};
+
+    #[tokio::test]
+    async fn test_parse_application_default_credentials() {
+        let test_creds = r#"{
+            "client_id": "***id***.apps.googleusercontent.com",
+            "client_secret": "***secret***",
+            "quota_project_id": "test_project",
+            "refresh_token": "***refresh***",
+            "type": "authorized_user"
+        }"#;
+
+        let cred_source: FlexibleCredentialSource =
+            serde_json::from_str(test_creds).expect("Valid creds to parse");
+
+        assert!(matches!(
+            cred_source,
+            FlexibleCredentialSource::AuthorizedUser(_)
+        ));
+
+        // Can't test converting this into a service account because it requires actually getting a key
+    }
+
+    #[tokio::test]
+    async fn test_parse_service_account_key() {
+        // Don't worry, even though the key is a real private_key, it's not used for anything
+        let test_creds = r#" {
+            "type": "service_account",
+            "project_id": "test_project",
+            "private_key_id": "***key_id***",
+            "private_key": "-----BEGIN PRIVATE KEY-----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\n2HSAcyIUcmr0gxlhRmC2Jq4=\n-----END PRIVATE KEY-----\n",
+            "client_email": "test_account@test.iam.gserviceaccount.com",
+            "client_id": "***id***",
+            "auth_uri": "https://accounts.google.com/o/oauth2/auth",
+            "token_uri": "https://oauth2.googleapis.com/token",
+            "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
+            "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/test_account%40test.iam.gserviceaccount.com",
+            "universe_domain": "googleapis.com"
+        }"#;
+
+        let cred_source: FlexibleCredentialSource =
+            serde_json::from_str(test_creds).expect("Valid creds to parse");
+
+        assert!(matches!(
+            cred_source,
+            FlexibleCredentialSource::ServiceAccount(_)
+        ));
+
+        let client = types::client();
+        let creds = cred_source
+            .try_into_service_account(&client)
+            .await
+            .expect("Valid creds to parse");
+
+        assert_eq!(
+            creds
+                .project_id(&client)
+                .await
+                .expect("Project ID to be present"),
+            "test_project".to_string(),
+            "Project ID should be parsed"
+        );
+    }
+
+    #[tokio::test]
+    async fn test_additional_service_account_keys() {
+        // Using test cases from https://github.com/golang/oauth2/blob/a835fc4358f6852f50c4c5c33fddcd1adade5b0a/google/google_test.go#L40
+        // We have to use a real private key because we validate private keys on parsing as well.
+        let k1 = r#"{
+            "private_key_id": "268f54e43a1af97cfc71731688434f45aca15c8b",
+            "private_key": "-----BEGIN PRIVATE KEY-----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\n2HSAcyIUcmr0gxlhRmC2Jq4=\n-----END PRIVATE KEY-----\n",
+            "client_email": "gopher@developer.gserviceaccount.com",
+            "client_id": "gopher.apps.googleusercontent.com",
+            "token_uri": "https://accounts.google.com/o/gophers/token",
+            "type": "service_account",
+            "audience": "https://testservice.googleapis.com/"
+        }"#;
+
+        let k3 = r#"{
+            "private_key_id": "268f54e43a1af97cfc71731688434f45aca15c8b",
+            "private_key": "-----BEGIN PRIVATE KEY-----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\n2HSAcyIUcmr0gxlhRmC2Jq4=\n-----END PRIVATE KEY-----\n",
+            "client_email": "gopher@developer.gserviceaccount.com",
+            "client_id": "gopher.apps.googleusercontent.com",
+            "token_uri": "https://accounts.google.com/o/gophers/token",
+            "type": "service_account"
+        }"#;
+
+        let client = types::client();
+        for key in [k1, k3] {
+            let cred_source: FlexibleCredentialSource =
+                serde_json::from_str(key).expect("Valid creds to parse");
+
+            assert!(matches!(
+                cred_source,
+                FlexibleCredentialSource::ServiceAccount(_)
+            ));
+
+            let creds = cred_source
+                .try_into_service_account(&client)
+                .await
+                .expect("Valid creds to parse");
+
+            assert!(
+                matches!(
+                    creds
+                        .project_id(&client)
+                        .await
+                        .expect_err("Project ID to not be present"),
+                    crate::Error::ProjectIdNotFound,
+                ),
+                "Project id should not be found here",
+            );
+        }
+    }
+}

src/lib.rs

@@ -94,6 +94,7 @@ mod custom_service_account;
 mod default_authorized_user;
 mod default_service_account;
 mod error;
+mod flexible_credential_source;
 mod gcloud_authorized_user;
 mod jwt;
 mod types;