Add GCS signed URL support (#5300)

* add util function for gcp sign url

* add string to sign and other sign functions

* add GoogleCloudStorageConfig::new and config and move functions to client

* add more code and rearrange struct

* add client_email for credential and return the signed url

* clean some code

* add client email for AuthorizedUserCredentials

* tidy some code

* format doc

* Add GcpSigningCredentialProvider for getting email

* add test

* Move some functions which shared by aws and gcp to utils.

* fix some bug and make it can get proper result

* remoe useless code

* tidy some code

* do not export host

* add sign_by_key

* Cleanup

* Add ServiceAccountKey

* Further tweaks

* add more scope for signing.

* tidy

* Tweak and add test

* Retry and handle errors for signBlob

---------

Co-authored-by: Raphael Taylor-Davies <r.taylordavies@googlemail.com>

object_store/src/aws/credential.rs

@@ -19,7 +19,7 @@ use crate::aws::{AwsCredentialProvider, STORE, STRICT_ENCODE_SET, STRICT_PATH_EN
 use crate::client::retry::RetryExt;
 use crate::client::token::{TemporaryToken, TokenCache};
 use crate::client::TokenProvider;
-use crate::util::hmac_sha256;
+use crate::util::{hex_digest, hex_encode, hmac_sha256};
 use crate::{CredentialProvider, Result, RetryConfig};
 use async_trait::async_trait;
 use bytes::Buf;
@@ -342,23 +342,6 @@ impl CredentialExt for RequestBuilder {
     }
 }
 
-/// Computes the SHA256 digest of `body` returned as a hex encoded string
-fn hex_digest(bytes: &[u8]) -> String {
-    let digest = ring::digest::digest(&ring::digest::SHA256, bytes);
-    hex_encode(digest.as_ref())
-}
-
-/// Returns `bytes` as a lower-case hex encoded string
-fn hex_encode(bytes: &[u8]) -> String {
-    use std::fmt::Write;
-    let mut out = String::with_capacity(bytes.len() * 2);
-    for byte in bytes {
-        // String writing is infallible
-        let _ = write!(out, "{byte:02x}");
-    }
-    out
-}
-
 /// Canonicalizes query parameters into the AWS canonical form
 ///
 /// <https://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html>

object_store/src/aws/mod.rs

@@ -43,6 +43,7 @@ use crate::client::list::ListClientExt;
 use crate::client::CredentialProvider;
 use crate::multipart::{MultipartStore, PartId};
 use crate::signer::Signer;
+use crate::util::STRICT_ENCODE_SET;
 use crate::{
     Error, GetOptions, GetResult, ListResult, MultipartId, MultipartUpload, ObjectMeta,
     ObjectStore, Path, PutMode, PutOptions, PutResult, Result, UploadPart,
@@ -64,16 +65,6 @@ pub use dynamo::DynamoCommit;
 pub use precondition::{S3ConditionalPut, S3CopyIfNotExists};
 pub use resolve::resolve_bucket_region;
 
-// http://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html
-//
-// Do not URI-encode any of the unreserved characters that RFC 3986 defines:
-// A-Z, a-z, 0-9, hyphen ( - ), underscore ( _ ), period ( . ), and tilde ( ~ ).
-pub(crate) const STRICT_ENCODE_SET: percent_encoding::AsciiSet = percent_encoding::NON_ALPHANUMERIC
-    .remove(b'-')
-    .remove(b'.')
-    .remove(b'_')
-    .remove(b'~');
-
 /// This struct is used to maintain the URI path encoding
 const STRICT_PATH_ENCODE_SET: percent_encoding::AsciiSet = STRICT_ENCODE_SET.remove(b'/');
 

object_store/src/gcp/builder.rs

@@ -21,14 +21,19 @@ use crate::gcp::credential::{
     ApplicationDefaultCredentials, InstanceCredentialProvider, ServiceAccountCredentials,
     DEFAULT_GCS_BASE_URL,
 };
-use crate::gcp::{credential, GcpCredential, GcpCredentialProvider, GoogleCloudStorage, STORE};
+use crate::gcp::{
+    credential, GcpCredential, GcpCredentialProvider, GcpSigningCredential,
+    GcpSigningCredentialProvider, GoogleCloudStorage, STORE,
+};
 use crate::{ClientConfigKey, ClientOptions, Result, RetryConfig, StaticCredentialProvider};
 use serde::{Deserialize, Serialize};
 use snafu::{OptionExt, ResultExt, Snafu};
 use std::str::FromStr;
 use std::sync::Arc;
 use url::Url;
 
+use super::credential::{AuthorizedUserSigningCredentials, InstanceSigningCredentialProvider};
+
 #[derive(Debug, Snafu)]
 enum Error {
     #[snafu(display("Missing bucket name"))]
@@ -107,6 +112,8 @@ pub struct GoogleCloudStorageBuilder {
     client_options: ClientOptions,
     /// Credentials
     credentials: Option<GcpCredentialProvider>,
+    /// Credentials for sign url
+    signing_cedentials: Option<GcpSigningCredentialProvider>,
 }
 
 /// Configuration keys for [`GoogleCloudStorageBuilder`]
@@ -202,6 +209,7 @@ impl Default for GoogleCloudStorageBuilder {
             client_options: ClientOptions::new().with_allow_http(true),
             url: None,
             credentials: None,
+            signing_cedentials: None,
         }
     }
 }
@@ -452,13 +460,13 @@ impl GoogleCloudStorageBuilder {
             Arc::new(StaticCredentialProvider::new(GcpCredential {
                 bearer: "".to_string(),
             })) as _
-        } else if let Some(credentials) = service_account_credentials {
+        } else if let Some(credentials) = service_account_credentials.clone() {
             Arc::new(TokenCredentialProvider::new(
                 credentials.token_provider()?,
                 self.client_options.client()?,
                 self.retry_config.clone(),
             )) as _
-        } else if let Some(credentials) = application_default_credentials {
+        } else if let Some(credentials) = application_default_credentials.clone() {
             match credentials {
                 ApplicationDefaultCredentials::AuthorizedUser(token) => {
                     Arc::new(TokenCredentialProvider::new(
@@ -483,13 +491,44 @@ impl GoogleCloudStorageBuilder {
             )) as _
         };
 
-        let config = GoogleCloudStorageConfig {
-            base_url: gcs_base_url,
+        let signing_credentials = if let Some(signing_credentials) = self.signing_cedentials {
+            signing_credentials
+        } else if disable_oauth {
+            Arc::new(StaticCredentialProvider::new(GcpSigningCredential {
+                email: "".to_string(),
+                private_key: None,
+            })) as _
+        } else if let Some(credentials) = service_account_credentials.clone() {
+            credentials.signing_credentials()?
+        } else if let Some(credentials) = application_default_credentials.clone() {
+            match credentials {
+                ApplicationDefaultCredentials::AuthorizedUser(token) => {
+                    Arc::new(TokenCredentialProvider::new(
+                        AuthorizedUserSigningCredentials::from(token)?,
+                        self.client_options.client()?,
+                        self.retry_config.clone(),
+                    )) as _
+                }
+                ApplicationDefaultCredentials::ServiceAccount(token) => {
+                    token.signing_credentials()?
+                }
+            }
+        } else {
+            Arc::new(TokenCredentialProvider::new(
+                InstanceSigningCredentialProvider::default(),
+                self.client_options.metadata_client()?,
+                self.retry_config.clone(),
+            )) as _
+        };
+
+        let config = GoogleCloudStorageConfig::new(
+            gcs_base_url,
             credentials,
+            signing_credentials,
             bucket_name,
-            retry_config: self.retry_config,
-            client_options: self.client_options,
-        };
+            self.retry_config,
+            self.client_options,
+        );
 
         Ok(GoogleCloudStorage {
             client: Arc::new(GoogleCloudStorageClient::new(config)?),

object_store/src/gcp/client.rs

@@ -24,19 +24,22 @@ use crate::client::s3::{
     ListResponse,
 };
 use crate::client::GetOptionsExt;
-use crate::gcp::{GcpCredential, GcpCredentialProvider, STORE};
+use crate::gcp::{GcpCredential, GcpCredentialProvider, GcpSigningCredentialProvider, STORE};
 use crate::multipart::PartId;
 use crate::path::{Path, DELIMITER};
+use crate::util::hex_encode;
 use crate::{
     ClientOptions, GetOptions, ListResult, MultipartId, PutMode, PutOptions, PutResult, Result,
     RetryConfig,
 };
 use async_trait::async_trait;
+use base64::prelude::BASE64_STANDARD;
+use base64::Engine;
 use bytes::{Buf, Bytes};
 use percent_encoding::{percent_encode, utf8_percent_encode, NON_ALPHANUMERIC};
 use reqwest::header::HeaderName;
 use reqwest::{header, Client, Method, RequestBuilder, Response, StatusCode};
-use serde::Serialize;
+use serde::{Deserialize, Serialize};
 use snafu::{OptionExt, ResultExt, Snafu};
 use std::sync::Arc;
 
@@ -101,6 +104,15 @@ enum Error {
 
     #[snafu(display("Got invalid multipart response: {}", source))]
     InvalidMultipartResponse { source: quick_xml::de::DeError },
+
+    #[snafu(display("Error signing blob: {}", source))]
+    SignBlobRequest { source: crate::client::retry::Error },
+
+    #[snafu(display("Got invalid signing blob repsonse: {}", source))]
+    InvalidSignBlobResponse { source: reqwest::Error },
+
+    #[snafu(display("Got invalid signing blob signature: {}", source))]
+    InvalidSignBlobSignature { source: base64::DecodeError },
 }
 
 impl From<Error> for crate::Error {
@@ -123,13 +135,39 @@ pub struct GoogleCloudStorageConfig {
 
     pub credentials: GcpCredentialProvider,
 
+    pub signing_credentials: GcpSigningCredentialProvider,
+
     pub bucket_name: String,
 
     pub retry_config: RetryConfig,
 
     pub client_options: ClientOptions,
 }
 
+impl GoogleCloudStorageConfig {
+    pub fn new(
+        base_url: String,
+        credentials: GcpCredentialProvider,
+        signing_credentials: GcpSigningCredentialProvider,
+        bucket_name: String,
+        retry_config: RetryConfig,
+        client_options: ClientOptions,
+    ) -> Self {
+        Self {
+            base_url,
+            credentials,
+            signing_credentials,
+            bucket_name,
+            retry_config,
+            client_options,
+        }
+    }
+
+    pub fn path_url(&self, path: &Path) -> String {
+        format!("{}/{}/{}", self.base_url, self.bucket_name, path)
+    }
+}
+
 /// A builder for a put request allowing customisation of the headers and query string
 pub struct PutRequest<'a> {
     path: &'a Path,
@@ -163,6 +201,21 @@ impl<'a> PutRequest<'a> {
     }
 }
 
+/// Sign Blob Request Body
+#[derive(Debug, Serialize)]
+struct SignBlobBody {
+    /// The payload to sign
+    payload: String,
+}
+
+/// Sign Blob Response
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct SignBlobResponse {
+    /// The signature for the payload
+    signed_blob: String,
+}
+
 #[derive(Debug)]
 pub struct GoogleCloudStorageClient {
     config: GoogleCloudStorageConfig,
@@ -197,6 +250,54 @@ impl GoogleCloudStorageClient {
         self.config.credentials.get_credential().await
     }
 
+    /// Create a signature from a string-to-sign using Google Cloud signBlob method.
+    /// form like:
+    /// ```plaintext
+    /// curl -X POST --data-binary @JSON_FILE_NAME \
+    /// -H "Authorization: Bearer OAUTH2_TOKEN" \
+    /// -H "Content-Type: application/json" \
+    /// "https://iamcredentials.googleapis.com/v1/projects/-/serviceAccounts/SERVICE_ACCOUNT_EMAIL:signBlob"
+    /// ```
+    ///
+    /// 'JSON_FILE_NAME' is a file containing the following JSON object:
+    /// ```plaintext
+    /// {
+    ///  "payload": "REQUEST_INFORMATION"
+    /// }
+    /// ```
+    pub async fn sign_blob(&self, string_to_sign: &str, client_email: &str) -> Result<String> {
+        let credential = self.get_credential().await?;
+        let body = SignBlobBody {
+            payload: BASE64_STANDARD.encode(string_to_sign),
+        };
+
+        let url = format!(
+            "https://iamcredentials.googleapis.com/v1/projects/-/serviceAccounts/{}:signBlob",
+            client_email
+        );
+
+        let response = self
+            .client
+            .post(&url)
+            .bearer_auth(&credential.bearer)
+            .json(&body)
+            .send_retry(&self.config.retry_config)
+            .await
+            .context(SignBlobRequestSnafu)?;
+
+        //If successful, the signature is returned in the signedBlob field in the response.
+        let response = response
+            .json::<SignBlobResponse>()
+            .await
+            .context(InvalidSignBlobResponseSnafu)?;
+
+        let signed_blob = BASE64_STANDARD
+            .decode(response.signed_blob)
+            .context(InvalidSignBlobSignatureSnafu)?;
+
+        Ok(hex_encode(&signed_blob))
+    }
+
     pub fn object_url(&self, path: &Path) -> String {
         let encoded = utf8_percent_encode(path.as_ref(), NON_ALPHANUMERIC);
         format!(