1 files changed, 134 insertions, 0 deletions
diff --git a/src/util.rs b/src/util.rs
new file mode 100644
index 0000000..11431e5
--- /dev/null
+++ b/src/util.rs
@@ -0,0 +1,134 @@
+use core::fmt;
+use std::ops::Deref;
+
+use axum::{
+	async_trait,
+	extract::FromRequestParts,
+	http::{header, request::Parts, HeaderName, StatusCode},
+	RequestPartsExt,
+};
+use sha2::{Digest, Sha256};
+use time::{format_description::FormatItem, macros::format_description, OffsetDateTime};
+
+pub struct RemoteIp(String);
+
+#[async_trait]
+impl<S> FromRequestParts<S> for RemoteIp
+where
+	S: Send + Sync,
+{
+	type Rejection = (StatusCode, &'static str);
+
+	async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self, Self::Rejection> {
+		if let Some(forwarded_for) = parts
+			.headers
+			.get(HeaderName::from_static("x-forwarded-for"))
+		{
+			match forwarded_for.to_str() {
+				Err(_e) => Err((StatusCode::INTERNAL_SERVER_ERROR, "server error")),
+				Ok(remoteip) => Ok(Self(remoteip.to_owned())),
+			}
+		} else {
+			Err((StatusCode::INTERNAL_SERVER_ERROR, "server error"))
+		}
+	}
+}
+
+impl Deref for RemoteIp {
+	type Target = str;
+
+	fn deref(&self) -> &Self::Target {
+		&self.0
+	}
+}
+
+const FMT: &[FormatItem<'_>] = format_description!("[year]-[month]-[day]");
+
+pub struct SessionId([u8; 4]);
+
+#[async_trait]
+impl<S> FromRequestParts<S> for SessionId
+where
+	S: Send + Sync,
+{
+	type Rejection = (StatusCode, &'static str);
+
+	async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self, Self::Rejection> {
+		let remote = parts
+			.extract::<RemoteIp>()
+			.await
+			.map(|rip| rip.0)
+			.unwrap_or(String::from("127.0.0.1"));
+
+		let agent = parts
+			.headers
+			.get(header::USER_AGENT)
+			.and_then(|ua| ua.to_str().ok())
+			.unwrap_or("unknown");
+
+		let date = OffsetDateTime::now_local().unwrap_or_else(|_| OffsetDateTime::now_utc());
+
+		let string = format!("{remote} - {agent} - {}", date.format(FMT).unwrap());
+
+		let mut hasher = Sha256::new();
+		hasher.update(string.as_bytes());
+		let hash = hasher.finalize();
+		let slc: [u8; 4] = hash.as_slice()[0..4].try_into().unwrap();
+
+		Ok(Self(slc))
+	}
+}
+
+impl fmt::Display for SessionId {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		for byte in self.0.as_slice() {
+			write!(f, "{byte:02X}")?;
+		}
+
+		Ok(())
+	}
+}
+
+pub struct Referer(String);
+
+#[async_trait]
+impl<S> FromRequestParts<S> for Referer
+where
+	S: Send + Sync,
+{
+	type Rejection = (StatusCode, &'static str);
+
+	async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self, Self::Rejection> {
+		if let Some(refer) = parts.headers.get(header::REFERER) {
+			match refer.to_str() {
+				Err(_e) => Err((StatusCode::INTERNAL_SERVER_ERROR, "server error")),
+				Ok(refer) => match url::Url::parse(refer) {
+					Err(_e) => Err((
+						StatusCode::INTERNAL_SERVER_ERROR,
+						"failed to parse referer url",
+					)),
+					Ok(url) => match url.host_str() {
+						None => Err((StatusCode::INTERNAL_SERVER_ERROR, "referer url had no host")),
+						Some(str) => Ok(Referer(str.to_owned())),
+					},
+				},
+			}
+		} else {
+			Err((StatusCode::INTERNAL_SERVER_ERROR, "server error"))
+		}
+	}
+}
+
+impl Deref for Referer {
+	type Target = str;
+
+	fn deref(&self) -> &Self::Target {
+		&self.0
+	}
+}
+
+impl fmt::Display for Referer {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		write!(f, "{}", self.0)
+	}
+}