1 files changed, 114 insertions, 0 deletions
diff --git a/src/api/helpers.rs b/src/api/helpers.rs
new file mode 100644
index 00000000..9ba32537
--- /dev/null
+++ b/src/api/helpers.rs
@@ -0,0 +1,114 @@
+use crate::Error;
+use idna::domain_to_unicode;
+
+/// Host to bucket
+///
+/// Convert a host, like "bucket.garage-site.tld" or "john.doe.com"
+/// to the corresponding bucket, resp. "bucket" and "john.doe.com"
+/// considering that ".garage-site.tld" is the "root domain".
+/// This behavior has been chosen to follow AWS S3 semantic.
+pub fn host_to_bucket<'a>(host: &'a str, root: &str) -> Option<&'a str> {
+	let root = root.trim_start_matches('.');
+	let label_root = root.chars().filter(|c| c == &'.').count() + 1;
+	let root = root.rsplit('.');
+	let mut host = host.rsplitn(label_root + 1, '.');
+	for root_part in root {
+		let host_part = host.next()?;
+		if root_part != host_part {
+			return None;
+		}
+	}
+	host.next()
+}
+
+/// Extract host from the authority section given by the HTTP host header
+///
+/// The HTTP host contains both a host and a port.
+/// Extracting the port is more complex than just finding the colon (:) symbol due to IPv6
+/// We do not use the collect pattern as there is no way in std rust to collect over a stack allocated value
+/// check here: https://docs.rs/collect_slice/1.2.0/collect_slice/
+pub fn authority_to_host(authority: &str) -> Result<String, Error> {
+	let mut iter = authority.chars().enumerate();
+	let (_, first_char) = iter
+		.next()
+		.ok_or_else(|| Error::BadRequest("Authority is empty".to_string()))?;
+
+	let split = match first_char {
+		'[' => {
+			let mut iter = iter.skip_while(|(_, c)| c != &']');
+			match iter.next() {
+				Some((_, ']')) => iter.next(),
+				_ => {
+					return Err(Error::BadRequest(format!(
+						"Authority {} has an illegal format",
+						authority
+					)))
+				}
+			}
+		}
+		_ => iter.find(|(_, c)| *c == ':'),
+	};
+
+	let authority = match split {
+		Some((i, ':')) => Ok(&authority[..i]),
+		None => Ok(authority),
+		Some((_, _)) => Err(Error::BadRequest(format!(
+			"Authority {} has an illegal format",
+			authority
+		))),
+	};
+	authority.map(|h| domain_to_unicode(h).0)
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	#[test]
+	fn authority_to_host_with_port() -> Result<(), Error> {
+		let domain = authority_to_host("[::1]:3902")?;
+		assert_eq!(domain, "[::1]");
+		let domain2 = authority_to_host("garage.tld:65200")?;
+		assert_eq!(domain2, "garage.tld");
+		let domain3 = authority_to_host("127.0.0.1:80")?;
+		assert_eq!(domain3, "127.0.0.1");
+		Ok(())
+	}
+
+	#[test]
+	fn authority_to_host_without_port() -> Result<(), Error> {
+		let domain = authority_to_host("[::1]")?;
+		assert_eq!(domain, "[::1]");
+		let domain2 = authority_to_host("garage.tld")?;
+		assert_eq!(domain2, "garage.tld");
+		let domain3 = authority_to_host("127.0.0.1")?;
+		assert_eq!(domain3, "127.0.0.1");
+		assert!(authority_to_host("[").is_err());
+		assert!(authority_to_host("[hello").is_err());
+		Ok(())
+	}
+
+	#[test]
+	fn host_to_bucket_test() {
+		assert_eq!(
+			host_to_bucket("john.doe.garage.tld", ".garage.tld").unwrap(),
+			"john.doe"
+		);
+
+		assert_eq!(
+			host_to_bucket("john.doe.garage.tld", "garage.tld").unwrap(),
+			"john.doe"
+		);
+
+		assert_eq!(host_to_bucket("john.doe.com", "garage.tld"), None);
+
+		assert_eq!(host_to_bucket("john.doe.com", ".garage.tld"), None);
+
+		assert_eq!(host_to_bucket("garage.tld", "garage.tld"), None);
+
+		assert_eq!(host_to_bucket("garage.tld", ".garage.tld"), None);
+
+		assert_eq!(host_to_bucket("not-garage.tld", "garage.tld"), None);
+		assert_eq!(host_to_bucket("not-garage.tld", ".garage.tld"), None);
+	}
+}