From f85780ac25d35755c257b1339508aaf55aca90e2 Mon Sep 17 00:00:00 2001
From: Chris Pick <chris@chrispick.com>
Date: Tue, 26 Mar 2024 17:16:37 -0400
Subject: [PATCH 1/2] Add `SignedURLOptions.start_time`

Allow the caller of `Client.signed_url()` to specify the time from which
the URL will be valid.  This allows signing URLs for future use.
---
 storage/src/sign.rs | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/storage/src/sign.rs b/storage/src/sign.rs
index 40a8a3c8..8e6bf5bc 100644
--- a/storage/src/sign.rs
+++ b/storage/src/sign.rs
@@ -1,7 +1,7 @@
 use std::collections::HashMap;
 use std::fmt::{Debug, Formatter};
 use std::ops::Deref;
-use std::time::Duration;
+use std::time::{Duration, SystemTime};
 
 use base64::prelude::*;
 use once_cell::sync::Lazy;
@@ -88,9 +88,14 @@ pub struct SignedURLOptions {
     /// Required.
     pub method: SignedURLMethod,
 
-    /// Expires is the expiration time on the signed URL. It must be
-    /// a datetime in the future. For SigningSchemeV4, the expiration may be no
-    /// more than seven days in the future.
+    /// StartTime is the time at which the signed URL starts being valid.
+    /// Defaults to the current time.
+    /// Optional.
+    pub start_time: Option<std::time::SystemTime>,
+
+    /// Expires is the duration of time, beginning at StartTime, within which
+    /// the signed URL is valid. For SigningSchemeV4, the duration may be no
+    /// more than 604800 seconds (7 days).
     /// Required.
     pub expires: std::time::Duration,
 
@@ -136,6 +141,7 @@ impl Default for SignedURLOptions {
     fn default() -> Self {
         Self {
             method: SignedURLMethod::GET,
+            start_time: None,
             expires: std::time::Duration::from_secs(600),
             content_type: None,
             headers: vec![],
@@ -165,8 +171,8 @@ pub(crate) fn create_signed_buffer(
     google_access_id: &str,
     opts: &SignedURLOptions,
 ) -> Result<(Vec<u8>, Url), SignedURLError> {
-    let now = OffsetDateTime::now_utc();
     validate_options(opts)?;
+    let start_time: OffsetDateTime = opts.start_time.unwrap_or_else(|| SystemTime::now()).into();
 
     let headers = v4_sanitize_headers(&opts.headers);
     // create base url
@@ -199,10 +205,10 @@ pub(crate) fn create_signed_buffer(
         .set_time_precision(TimePrecision::Second { decimal_digits: None })
         .encode();
 
-    let timestamp = now.format(&Iso8601::<CONFIG>).unwrap();
+    let timestamp = start_time.format(&Iso8601::<CONFIG>).unwrap();
     let credential_scope = format!(
         "{}/auto/storage/goog4_request",
-        now.format(format_description!("[year][month][day]")).unwrap()
+        start_time.format(format_description!("[year][month][day]")).unwrap()
     );
 
     // append query parameters

From 9cf27dc71bcf9af4a3f33b31cf749303c80bc1b3 Mon Sep 17 00:00:00 2001
From: Chris Pick <chris@chrispick.com>
Date: Wed, 10 Apr 2024 17:05:12 -0400
Subject: [PATCH 2/2] Fix `SignedURLOptions.start_time` clippy warning

Run `cargo clippy --fix`.

https://github.com/yoshidan/google-cloud-rust/pull/246#issuecomment-2044304059
---
 storage/src/sign.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/storage/src/sign.rs b/storage/src/sign.rs
index 8e6bf5bc..9dc21a72 100644
--- a/storage/src/sign.rs
+++ b/storage/src/sign.rs
@@ -172,7 +172,7 @@ pub(crate) fn create_signed_buffer(
     opts: &SignedURLOptions,
 ) -> Result<(Vec<u8>, Url), SignedURLError> {
     validate_options(opts)?;
-    let start_time: OffsetDateTime = opts.start_time.unwrap_or_else(|| SystemTime::now()).into();
+    let start_time: OffsetDateTime = opts.start_time.unwrap_or_else(SystemTime::now).into();
 
     let headers = v4_sanitize_headers(&opts.headers);
     // create base url