fix: normalize_host handles IPv6 bracket notation

Extract strip_port_from_host into shared utils module and update normalize_host to properly strip brackets from IPv6 addresses like [::1]:443 -> ::1 instead of incorrectly using split(':').next().

src/config/dynamic_config.rs

@@ -50,8 +50,14 @@ pub fn build_routing_table(sites: &[SiteConfig]) -> HashMap<String, SiteConfig>
 }
 
 pub fn normalize_host(host: &str) -> String {
-    let lower = host.to_lowercase();
-    lower.split(':').next().unwrap_or(&lower).to_string()
+    let stripped = crate::utils::strip_port_from_host(host);
+    let lower = stripped.to_lowercase();
+    lower
+        .strip_prefix('[')
+        .unwrap_or(&lower)
+        .strip_suffix(']')
+        .unwrap_or(&lower)
+        .to_string()
 }
 
 #[derive(Debug, Deserialize, Clone, PartialEq)]
@@ -304,6 +310,26 @@ mod tests {
         assert_eq!(normalize_host(""), "");
     }
 
+    #[test]
+    fn normalize_host_ipv6_with_port() {
+        assert_eq!(normalize_host("[::1]:443"), "::1");
+    }
+
+    #[test]
+    fn normalize_host_ipv6_long_with_port() {
+        assert_eq!(normalize_host("[2001:db8::1]:8080"), "2001:db8::1");
+    }
+
+    #[test]
+    fn normalize_host_ipv6_bare() {
+        assert_eq!(normalize_host("[::1]"), "::1");
+    }
+
+    #[test]
+    fn normalize_host_ipv6_uppercase() {
+        assert_eq!(normalize_host("[2001:DB8::1]:443"), "2001:db8::1");
+    }
+
     #[test]
     fn routing_table_lookup_finds_site() {
         let config = test_fixtures::test_dynamic_config();

src/lib.rs

@@ -8,3 +8,4 @@ pub mod rate_limit;
 pub mod server;
 pub mod shutdown;
 pub mod tls;
+pub mod utils;

src/tls/redirect.rs

@@ -13,19 +13,7 @@ use crate::config::static_config::ListenerConfig;
 
 const ACME_CHALLENGE_PREFIX: &str = "/.well-known/acme-challenge/";
 
-fn strip_port_from_host(host: &str) -> &str {
-    if host.starts_with('[') {
-        if let Some(bracket_end) = host.find(']') {
-            &host[..bracket_end + 1]
-        } else {
-            host
-        }
-    } else if let Some(colon_pos) = host.rfind(':') {
-        &host[..colon_pos]
-    } else {
-        host
-    }
-}
+use crate::utils::strip_port_from_host;
 
 pub fn build_redirect_url(host: &str, https_port: u16, path: &str, query: &str) -> String {
     let hostname = strip_port_from_host(host);
@@ -218,29 +206,4 @@ mod tests {
         let url = build_redirect_url("203.0.113.10", 443, "/", "");
         assert_eq!(url, "https://203.0.113.10/");
     }
-
-    #[test]
-    fn test_strip_port_from_host_plain() {
-        assert_eq!(strip_port_from_host("example.com"), "example.com");
-    }
-
-    #[test]
-    fn test_strip_port_from_host_with_port() {
-        assert_eq!(strip_port_from_host("example.com:8080"), "example.com");
-    }
-
-    #[test]
-    fn test_strip_port_from_host_ipv6_bare() {
-        assert_eq!(strip_port_from_host("[::1]"), "[::1]");
-    }
-
-    #[test]
-    fn test_strip_port_from_host_ipv6_with_port() {
-        assert_eq!(strip_port_from_host("[::1]:8080"), "[::1]");
-    }
-
-    #[test]
-    fn test_strip_port_from_host_ipv4_with_port() {
-        assert_eq!(strip_port_from_host("192.168.1.1:8080"), "192.168.1.1");
-    }
 }

src/utils.rs

@@ -0,0 +1,48 @@
+pub fn strip_port_from_host(host: &str) -> &str {
+    if host.starts_with('[') {
+        if let Some(bracket_end) = host.find(']') {
+            &host[..bracket_end + 1]
+        } else {
+            host
+        }
+    } else if let Some(colon_pos) = host.rfind(':') {
+        &host[..colon_pos]
+    } else {
+        host
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn strip_port_plain() {
+        assert_eq!(strip_port_from_host("example.com"), "example.com");
+    }
+
+    #[test]
+    fn strip_port_with_port() {
+        assert_eq!(strip_port_from_host("example.com:8080"), "example.com");
+    }
+
+    #[test]
+    fn strip_port_ipv6_bare() {
+        assert_eq!(strip_port_from_host("[::1]"), "[::1]");
+    }
+
+    #[test]
+    fn strip_port_ipv6_with_port() {
+        assert_eq!(strip_port_from_host("[::1]:8080"), "[::1]");
+    }
+
+    #[test]
+    fn strip_port_ipv6_with_long_address() {
+        assert_eq!(strip_port_from_host("[2001:db8::1]:8080"), "[2001:db8::1]");
+    }
+
+    #[test]
+    fn strip_port_ipv4_with_port() {
+        assert_eq!(strip_port_from_host("192.168.1.1:8080"), "192.168.1.1");
+    }
+}