Do what chrono does (#341)

* Do what chrono does

* Target specific dependencies

Cargo.toml

@@ -15,12 +15,19 @@ rust-version = "1.67.0"
 [dependencies]
 serde_json = "1.0"
 serde = {version = "1.0", features = ["derive"] }
-ring = { version = "0.17.4", features = ["std"] }
 base64 = "0.21.0"
 # For PEM decoding
 pem = {version = "3", optional = true}
 simple_asn1 = {version = "0.6", optional = true}
 
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+ring = { version = "0.17.4", features = ["std"] }
+
+
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+js-sys = "0.3"
+ring = { version = "0.17.4", features = ["std", "wasm32_unknown_unknown_js"] }
+
 [dev-dependencies]
 # For the custom time example
 time = "0.3"

src/validation.rs

@@ -2,7 +2,6 @@ use std::borrow::Cow;
 use std::collections::HashSet;
 use std::fmt;
 use std::marker::PhantomData;
-use std::time::{SystemTime, UNIX_EPOCH};
 
 use serde::de::{self, Visitor};
 use serde::{Deserialize, Deserializer};
@@ -137,9 +136,18 @@ impl Default for Validation {
 }
 
 /// Gets the current timestamp in the format expected by JWTs.
+#[cfg(not(all(target_arch = "wasm32", not(any(target_os = "emscripten", target_os = "wasi")))))]
+#[must_use]
 pub fn get_current_timestamp() -> u64 {
-    let start = SystemTime::now();
-    start.duration_since(UNIX_EPOCH).expect("Time went backwards").as_secs()
+    let start = std::time::SystemTime::now();
+    start.duration_since(std::time::UNIX_EPOCH).expect("Time went backwards").as_secs()
+}
+
+/// Gets the current timestamp in the format expected by JWTs.
+#[cfg(all(target_arch = "wasm32", not(any(target_os = "emscripten", target_os = "wasi"))))]
+#[must_use]
+pub fn get_current_timestamp() -> u64 {
+    js_sys::Date::new_0().get_time() as u64 / 1000
 }
 
 #[derive(Deserialize)]