Restore server name validation

CHANGELOG.md

@@ -16,6 +16,8 @@ Breaking changes:
     * Note that hashes are generally only guaranteed consistent in the lifetime of the program
       though, so do not persist them!
   * The `hostname` methods have been updated to return string slices instead of `&url::Host`
+* `Error::InvalidHost` has been renamed to `Error::InvalidServerName`, because it also covers errors
+  in the port, not just the host part section of the server name
 
 Improvements:
 

src/error.rs

@@ -11,8 +11,8 @@ pub enum Error {
     InvalidCharacters,
     /// The localpart of the ID string is not valid (because it is empty).
     InvalidLocalPart,
-    /// The domain part of the the ID string is not a valid IP address or DNS name.
+    /// The server name part of the the ID string is not a valid server name.
-    InvalidHost,
+    InvalidServerName,
     /// The ID exceeds 255 bytes (or 32 codepoints for a room version ID.)
     MaximumLengthExceeded,
     /// The ID is less than 4 characters (or is an empty room version ID.)
@@ -28,7 +28,7 @@ impl Display for Error {
         let message = match self {
             Error::InvalidCharacters => "localpart contains invalid characters",
             Error::InvalidLocalPart => "localpart is empty",
-            Error::InvalidHost => "server name is not a valid IP address or domain name",
+            Error::InvalidServerName => "server name is not a valid IP address or domain name",
             Error::MaximumLengthExceeded => "ID exceeds 255 bytes",
             Error::MinimumLengthNotSatisfied => "ID must be at least 4 characters",
             Error::MissingDelimiter => "colon is required between localpart and server name",

src/event_id.rs

@@ -162,10 +162,10 @@ mod tests {
         assert_eq!(id_str.len(), 31);
     }
 
-    /*#[test]
+    #[test]
     fn generate_random_invalid_event_id() {
         assert!(EventId::new("").is_err());
-    }*/
+    }
 
     #[test]
     fn serialize_valid_original_event_id() {
@@ -275,11 +275,11 @@ mod tests {
         );
     }
 
-    /*#[test]
+    #[test]
     fn invalid_event_id_host() {
         assert_eq!(
             EventId::try_from("$39hvsi03hlne:/").unwrap_err(),
-            Error::InvalidHost
+            Error::InvalidServerName
         );
     }
 
@@ -287,7 +287,7 @@ mod tests {
     fn invalid_event_id_port() {
         assert_eq!(
             EventId::try_from("$39hvsi03hlne:example.com:notaport").unwrap_err(),
-            Error::InvalidHost
+            Error::InvalidServerName
         );
-    }*/
+    }
 }

src/lib.rs

@@ -23,7 +23,8 @@ use serde::de::{self, Deserialize as _, Deserializer, Unexpected};
 pub use crate::device_id::DeviceId;
 pub use crate::{
     error::Error, event_id::EventId, room_alias_id::RoomAliasId, room_id::RoomId,
-    room_id_or_room_alias_id::RoomIdOrAliasId, room_version_id::RoomVersionId, user_id::UserId,
+    room_id_or_room_alias_id::RoomIdOrAliasId, room_version_id::RoomVersionId,
+    server_name::is_valid_server_name, user_id::UserId,
 };
 
 #[macro_use]
@@ -38,6 +39,7 @@ mod room_alias_id;
 mod room_id;
 mod room_id_or_room_alias_id;
 mod room_version_id;
+mod server_name;
 mod user_id;
 
 /// All identifiers must be 255 bytes or less.
@@ -79,8 +81,8 @@ fn parse_id(id: &str, valid_sigils: &[char]) -> Result<NonZeroU8, Error> {
     validate_id(id, valid_sigils)?;
 
     let colon_idx = id.find(':').ok_or(Error::MissingDelimiter)?;
-    if colon_idx == id.len() - 1 {
+    if !is_valid_server_name(&id[colon_idx + 1..]) {
-        return Err(Error::InvalidHost);
+        return Err(Error::InvalidServerName);
     }
 
     match NonZeroU8::new(colon_idx as u8) {

src/room_alias_id.rs

@@ -144,11 +144,11 @@ mod tests {
         );
     }
 
-    /*#[test]
+    #[test]
     fn invalid_room_alias_id_host() {
         assert_eq!(
             RoomAliasId::try_from("#ruma:/").unwrap_err(),
-            Error::InvalidHost
+            Error::InvalidServerName
         );
     }
 
@@ -156,7 +156,7 @@ mod tests {
     fn invalid_room_alias_id_port() {
         assert_eq!(
             RoomAliasId::try_from("#ruma:example.com:notaport").unwrap_err(),
-            Error::InvalidHost
+            Error::InvalidServerName
         );
-    }*/
+    }
 }

src/room_id.rs

@@ -101,10 +101,10 @@ mod tests {
         assert_eq!(id_str.len(), 31);
     }
 
-    /*#[test]
+    #[test]
     fn generate_random_invalid_room_id() {
         assert!(RoomId::new("").is_err());
-    }*/
+    }
 
     #[test]
     fn serialize_valid_room_id() {
@@ -162,11 +162,11 @@ mod tests {
         );
     }
 
-    /*#[test]
+    #[test]
     fn invalid_room_id_host() {
         assert_eq!(
             RoomId::try_from("!29fhd83h92h0:/").unwrap_err(),
-            Error::InvalidHost
+            Error::InvalidServerName
         );
     }
 
@@ -174,7 +174,7 @@ mod tests {
     fn invalid_room_id_port() {
         assert_eq!(
             RoomId::try_from("!29fhd83h92h0:example.com:notaport").unwrap_err(),
-            Error::InvalidHost
+            Error::InvalidServerName
         );
-    }*/
+    }
 }

src/server_name.rs

@@ -0,0 +1,96 @@
+/// Check whether a given string is a valid server name according to [the specification][].
+///
+/// [the specification]: https://matrix.org/docs/spec/appendices#server-name
+pub fn is_valid_server_name(name: &str) -> bool {
+    use std::net::Ipv6Addr;
+
+    let end_of_host = if name.starts_with('[') {
+        let end_of_ipv6 = match name.find(']') {
+            Some(idx) => idx,
+            None => return false,
+        };
+
+        if name[1..end_of_ipv6].parse::<Ipv6Addr>().is_err() {
+            return false;
+        }
+
+        end_of_ipv6 + 1
+    } else {
+        let end_of_host = name.find(':').unwrap_or_else(|| name.len());
+
+        if name[..end_of_host]
+            .bytes()
+            .any(|byte| !(byte.is_ascii_alphanumeric() || byte == b'-' || byte == b'.'))
+        {
+            return false;
+        }
+
+        end_of_host
+    };
+
+    if name.len() == end_of_host {
+        true
+    } else if name.as_bytes()[end_of_host] != b':' {
+        // hostname is followed by something other than ":port"
+        false
+    } else {
+        // are the remaining characters after ':' a valid port?
+        name[end_of_host + 1..].parse::<u16>().is_ok()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::is_valid_server_name;
+
+    #[test]
+    fn ipv4_host() {
+        assert!(is_valid_server_name("127.0.0.1"));
+    }
+
+    #[test]
+    fn ipv4_host_and_port() {
+        assert!(is_valid_server_name("1.1.1.1:12000"));
+    }
+
+    #[test]
+    fn ipv6() {
+        assert!(is_valid_server_name("[::1]"));
+    }
+
+    #[test]
+    fn ipv6_with_port() {
+        assert!(is_valid_server_name("[1234:5678::abcd]:5678"));
+    }
+
+    #[test]
+    fn dns_name() {
+        assert!(is_valid_server_name("example.com"));
+    }
+
+    #[test]
+    fn dns_name_with_port() {
+        assert!(is_valid_server_name("ruma.io:8080"));
+    }
+
+    #[test]
+    fn invalid_ipv6() {
+        assert!(!is_valid_server_name("[test::1]"));
+    }
+
+    #[test]
+    fn ipv4_with_invalid_port() {
+        assert!(!is_valid_server_name("127.0.0.1:"));
+    }
+
+    #[test]
+    fn ipv6_with_invalid_port() {
+        assert!(!is_valid_server_name("[fe80::1]:100000"));
+        assert!(!is_valid_server_name("[fe80::1]!"));
+    }
+
+    #[test]
+    fn dns_name_with_invalid_port() {
+        assert!(!is_valid_server_name("matrix.org:hello"));
+    }
+}

src/user_id.rs

@@ -209,16 +209,19 @@ mod tests {
         );
     }
 
-    /*#[test]
+    #[test]
     fn invalid_user_id_host() {
-        assert_eq!(UserId::try_from("@carl:/").unwrap_err(), Error::InvalidHost);
+        assert_eq!(
+            UserId::try_from("@carl:/").unwrap_err(),
+            Error::InvalidServerName
+        );
     }
 
     #[test]
     fn invalid_user_id_port() {
         assert_eq!(
             UserId::try_from("@carl:example.com:notaport").unwrap_err(),
-            Error::InvalidHost
+            Error::InvalidServerName
         );
-    }*/
+    }
 }