Switch to using UIDs

src/types/request.rs

@@ -296,7 +296,7 @@ impl Request {
     where
         UserData: Serialize + DeserializeOwned
     {
-        Ok(self.manager.get_user(self.certificate())?)
+        Ok(self.manager.get_user_by_cert(self.certificate())?)
     }
 
     #[cfg(feature="user_management")]

src/user_management/manager.rs

@@ -1,5 +1,7 @@
 use serde::{Serialize, de::DeserializeOwned};
 
+use std::convert::TryInto;
+
 use crate::user_management::{User, Result};
 use crate::user_management::user::{RegisteredUser, NotSignedInUser, PartialUser};
 
@@ -21,8 +23,9 @@ pub struct UserManager {
     /// [`lookup_user()`]: Self::lookup_user
     /// [`lookup_certificate()`]: Self::lookup_certificate
     pub db: sled::Db,
-    pub (crate) users: sled::Tree, // user_id:String maps to data:UserData
-    pub (crate) certificates: sled::Tree, // certificate:u64 maps to data:CertificateData
+    pub (crate) users: sled::Tree, // user_id:u64 maps to data:PartialUser
+    pub (crate) certificates: sled::Tree, // fingerprint:[u8; 32] maps to uid:u64
+    pub (crate) usernames: sled::Tree, // username:String maps to uid:u64
 }
 
 impl UserManager {
@@ -35,6 +38,7 @@ impl UserManager {
        Ok(Self {
            users: db.open_tree("gay.emii.kochab.users")?,
            certificates: db.open_tree("gay.emii.kochab.certificates")?,
+           usernames: db.open_tree("gay.emii.kochab.usernames")?,
            db,
        })
     }
@@ -44,29 +48,60 @@ impl UserManager {
     /// # Errors
     /// An error is thrown if there is an error reading from the database or if data
     /// recieved from the database is corrupt
-    pub fn lookup_certificate(&self, cert: [u8; 32]) -> Result<Option<String>> {
+    ///
+    /// [`None`] can be returned if their is no user with this certificate.
+    pub fn lookup_certificate<UserData: Serialize + DeserializeOwned>(
+        &self,
+        cert: [u8; 32]
+    ) -> Result<Option<RegisteredUser<UserData>>> {
         if let Some(bytes) = self.certificates.get(cert)? {
-            Ok(Some(std::str::from_utf8(bytes.as_ref())?.to_string()))
+            let id = u64::from_le_bytes(bytes.as_ref().try_into()?);
+            Ok(Some(
+                self.lookup_user(id)?
+                    .ok_or(super::DeserializeError::InvalidReference(id))?
+            ))
         } else {
             Ok(None)
         }
     }
 
-    /// Lookup information about a user by username
+    /// Get the user with the specified username
     ///
     /// # Errors
     /// An error is thrown if there is an error reading from the database or if data
     /// recieved from the database is corrupt
-    pub fn lookup_user<UserData>(
+    ///
+    /// [`None`] can be returned if their is no user with this username.
+    pub fn lookup_username<UserData: Serialize + DeserializeOwned>(
         &self,
         username: impl AsRef<str>
+    ) -> Result<Option<RegisteredUser<UserData>>> {
+        if let Some(bytes) = self.usernames.get(username.as_ref())? {
+            let id = u64::from_le_bytes(bytes.as_ref().try_into()?);
+            Ok(Some(
+                self.lookup_user(id)?
+                    .ok_or(super::DeserializeError::InvalidReference(id))?
+            ))
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Lookup a user by uid
+    ///
+    /// # Errors
+    /// An error is thrown if there is an error reading from the database or if data
+    /// recieved from the database is corrupt
+    pub fn lookup_user<UserData>(
+        &self,
+        uid: u64,
     ) -> Result<Option<RegisteredUser<UserData>>>
     where
         UserData: Serialize + DeserializeOwned
     {
-        if let Some(bytes) = self.users.get(username.as_ref())? {
+        if let Some(bytes) = self.users.get(uid.to_le_bytes())? {
             let inner: PartialUser<UserData> = bincode::deserialize_from(bytes.as_ref())?;
-            Ok(Some(RegisteredUser::new(username.as_ref().to_owned(), None, self.clone(), inner)))
+            Ok(Some(RegisteredUser::new(uid, None, self.clone(), inner)))
         } else {
             Ok(None)
         }
@@ -79,20 +114,18 @@ impl UserManager {
     /// the database is corrupt
     pub fn all_users<UserData>(
         &self,
-    ) -> Vec<RegisteredUser<UserData>>
+    ) -> impl Iterator<Item = Result<RegisteredUser<UserData>>>
     where
         UserData: Serialize + DeserializeOwned
     {
+        let this = self.clone();
         self.users.iter()
-            .map(|result| {
-                let (username, bytes) = result.expect("Failed to connect to database");
-                let inner: PartialUser<UserData> = bincode::deserialize_from(bytes.as_ref())
-                    .expect("Received malformed data from database");
-                let username = String::from_utf8(username.to_vec())
-                    .expect("Malformed username in database");
-                RegisteredUser::new(username, None, self.clone(), inner)
+            .map(move|result| {
+                let (uid, bytes) = result?;
+                let inner: PartialUser<UserData> = bincode::deserialize_from(bytes.as_ref())?;
+                let uid = u64::from_le_bytes(uid.as_ref().try_into()?);
+                Ok(RegisteredUser::new(uid, None, this.clone(), inner))
             })
-            .collect()
     }
 
     /// Attempt to determine the user who sent a request based on the certificate.
@@ -103,7 +136,7 @@ impl UserManager {
     ///
     /// # Panics
     /// Pancis if the database is corrupt
-    pub fn get_user<UserData>(
+    pub fn get_user_by_cert<UserData>(
         &self,
         cert: Option<&[u8; 32]>
     ) -> Result<User<UserData>>
@@ -111,9 +144,7 @@ impl UserManager {
         UserData: Serialize + DeserializeOwned
     {
         if let Some(certificate) = cert {
-            if let Some(username) = self.lookup_certificate(*certificate)? {
-                let user_inner = self.lookup_user(&username)?
-                    .expect("Database corruption: Certificate data refers to non-existant user");
+            if let Some(user_inner) = self.lookup_certificate(*certificate)? {
                 Ok(User::SignedIn(user_inner.with_cert(*certificate)))
             } else {
                 Ok(User::NotSignedIn(NotSignedInUser {

src/user_management/mod.rs

@@ -93,12 +93,24 @@ impl From<bincode::Error> for UserManagerError {
     }
 }
 
+impl From<std::array::TryFromSliceError> for UserManagerError {
+    fn from(error: std::array::TryFromSliceError) -> Self {
+        Self::DeserializeError(error.into())
+    }
+}
+
 impl From<std::str::Utf8Error> for UserManagerError {
     fn from(error: std::str::Utf8Error) -> Self {
         Self::DeserializeError(error.into())
     }
 }
 
+impl From<DeserializeError> for UserManagerError {
+    fn from(error: DeserializeError) -> Self {
+        Self::DeserializeError(error)
+    }
+}
+
 #[cfg(feature = "user_management_advanced")]
 impl From<argon2::Error> for UserManagerError {
     fn from(error: argon2::Error) -> Self {
@@ -159,12 +171,18 @@ pub enum DeserializeError {
     /// version, or you're using a database that was created by a version of kochab that
     /// was released after the one you're currently using.  However, as of right now, no
     /// such release exists or is planned.
-    UidError(std::str::Utf8Error),
+    UidError(std::array::TryFromSliceError),
 
     /// There was an error deserializing a username
     ///
     /// Indicates data corruption or a misaligned database version
     UsernameError(std::str::Utf8Error),
+
+    /// A certificate or username was linked to a non-existant user id
+    ///
+    /// This error should not occur, except in very unlikely scenarios, or if there's a
+    /// bug with kochab
+    InvalidReference(u64),
 }
 
 impl From<bincode::Error> for DeserializeError {
@@ -173,6 +191,12 @@ impl From<bincode::Error> for DeserializeError {
     }
 }
 
+impl From<std::array::TryFromSliceError> for DeserializeError {
+    fn from(error: std::array::TryFromSliceError) -> Self {
+        Self::UidError(error)
+    }
+}
+
 impl From<std::str::Utf8Error> for DeserializeError {
     fn from(error: std::str::Utf8Error) -> Self {
         Self::UsernameError(error)
@@ -185,6 +209,7 @@ impl std::error::Error for DeserializeError {
             Self::StructError(e) => Some(e),
             Self::UidError(e) => Some(e),
             Self::UsernameError(e) => Some(e),
+            Self::InvalidReference(_) => None,
         }
     }
 }
@@ -198,6 +223,8 @@ impl std::fmt::Display for DeserializeError {
                 write!(f, "Got wrong number of bytes while deserializing user ID: {}", e),
             Self::UsernameError(e) =>
                 write!(f, "Got invalid UTF-8 instead of username: {}", e),
+            Self::InvalidReference(uid) =>
+                write!(f, "Database refers to nonexistant user with userid {}", uid),
         }
     }
 }

src/user_management/user.rs

@@ -48,6 +48,7 @@ lazy_static::lazy_static! {
 pub (crate) struct PartialUser<UserData> {
     pub data: UserData,
     pub certificates: Vec<[u8; 32]>,
+    pub username: String,
     #[cfg(feature = "user_management_advanced")]
     pub pass_hash: Option<(Vec<u8>, [u8; 32])>,
 }
@@ -58,12 +59,12 @@ impl<UserData> PartialUser<UserData> {
     ///
     /// This MUST be called if the user data is modified using the AsMut trait, or else
     /// changes will not be written to the database
-    fn store(&self, tree: &sled::Tree, username: impl AsRef<[u8]>) -> Result<()>
+    fn store(&self, tree: &sled::Tree, uid: u64) -> Result<()>
     where
         UserData: Serialize
     {
         tree.insert(
-            &username,
+            uid.to_le_bytes(),
             bincode::serialize(&self)?,
         )?;
         Ok(())
@@ -117,26 +118,48 @@ impl NotSignedInUser {
         if self.manager.users.contains_key(username.as_str())? {
             Err(super::UserManagerError::UsernameNotUnique)
         } else {
-            info!("User {} registered!", username);
 
-            let mut newser = RegisteredUser::new(
+            // Create the partial user that will go into the database.  We can't create
+            // the full user yet, since the ID won't be generated until we perform the
+            // insert.
+            let partial = PartialUser {
                 username,
+                data: UserData::default(),
+                certificates: vec![self.certificate],
+                #[cfg(feature = "user_management_advanced")]
+                pass_hash: None,
+            };
+            let serialized = bincode::serialize(&partial)?;
+
+            // Insert the user into the three relevant tables, thus finalizing their
+            // creation.  This also produces the user id.
+            let id = (&self.manager.users, &self.manager.certificates, &self.manager.usernames)
+                .transaction(|(tx_usr, tx_crt, tx_nam)| {
+                    let id = tx_usr.generate_id()?;
+                    let id_bytes = id.to_le_bytes();
+
+                    tx_usr.insert(
+                        &id_bytes,
+                        serialized.as_slice(),
+                    )?;
+                    tx_crt.insert(
+                        &partial.certificates[0],
+                        &id_bytes,
+                    )?;
+                    tx_nam.insert(
+                        partial.username.as_bytes(),
+                        &id_bytes,
+                    )?;
+                    Ok(id)
+                })?;
+            info!("User {}#{:08x} registered!", partial.username, id);
+
+            Ok(RegisteredUser::new(
+                id,
                 Some(self.certificate),
                 self.manager,
-                PartialUser {
-                    data: UserData::default(),
-                    certificates: Vec::with_capacity(1),
-                    #[cfg(feature = "user_management_advanced")]
-                    pass_hash: None,
-                },
-            );
-
-            // As a nice bonus, calling add_certificate with a user not yet in the
-            // database creates the user and adds the certificate in a single transaction.
-            // Because of this, we can delegate here ^^
-            newser.add_certificate(self.certificate)?;
-
-            Ok(newser)
+                partial,
+            ))
         }
     }
 
@@ -172,7 +195,7 @@ impl NotSignedInUser {
         username: &str,
         password: Option<&[u8]>,
     ) -> Result<Option<RegisteredUser<UserData>>> {
-        if let Some(mut user) = self.manager.lookup_user(username)? {
+        if let Some(mut user) = self.manager.lookup_username(username)? {
             // Perform password check, if caller wants
             if let Some(password) = password {
                 if !user.check_password(password)? {
@@ -195,7 +218,7 @@ impl NotSignedInUser {
 ///
 /// For more information about the user lifecycle and sign-in stages, see [`User`]
 pub struct RegisteredUser<UserData: Serialize + DeserializeOwned> {
-    username: String,
+    uid: u64,
     active_certificate: Option<[u8; 32]>,
     manager: UserManager,
     inner: PartialUser<UserData>,
@@ -207,13 +230,13 @@ impl<UserData: Serialize + DeserializeOwned> RegisteredUser<UserData> {
 
     /// Create a new user from parts
     pub (crate) fn new(
-        username: String,
+        uid: u64,
         active_certificate: Option<[u8; 32]>,
         manager: UserManager,
         inner: PartialUser<UserData>
     ) -> Self {
         Self {
-            username,
+            uid,
             active_certificate,
             manager,
             inner,
@@ -246,9 +269,19 @@ impl<UserData: Serialize + DeserializeOwned> RegisteredUser<UserData> {
 
     /// Get the user's current username.
     ///
-    /// NOTE: This is not guaranteed not to change.
+    /// NOTE: This is not guaranteed not to change.  If you need an immutable reference to
+    /// this user, prefer their [UID], which is guaranteed static.
+    ///
+    /// [UID]: Self::uid()
     pub fn username(&self) -> &String {
-        &self.username
+        &self.inner.username
+    }
+
+    /// Get the user's id.
+    ///
+    /// This is not guaranteed not to change.
+    pub fn uid(&self) -> u64 {
+        self.uid
     }
 
     #[cfg(feature = "user_management_advanced")]
@@ -328,7 +361,7 @@ impl<UserData: Serialize + DeserializeOwned> RegisteredUser<UserData> {
     where
         UserData: Serialize
     {
-        self.inner.store(&self.manager.users, &self.username)?;
+        self.inner.store(&self.manager.users, self.uid)?;
         self.has_changed = false;
         Ok(())
     }
@@ -346,16 +379,17 @@ impl<UserData: Serialize + DeserializeOwned> RegisteredUser<UserData> {
         self.inner.certificates.push(certificate);
 
         let inner_serialized = bincode::serialize(&self.inner)?;
+        let uid_bytes = self.uid.to_le_bytes();
 
         (&self.manager.users, &self.manager.certificates)
             .transaction(|(tx_usr, tx_crt)| {
                 tx_usr.insert(
-                    self.username.as_str(),
+                    &uid_bytes,
                     inner_serialized.clone(),
                 )?;
                 tx_crt.insert(
                     &certificate,
-                    self.username.as_bytes(),
+                    &uid_bytes,
                 )?;
                 Ok(())
             })?;
@@ -384,9 +418,12 @@ impl<UserData: Serialize + DeserializeOwned> RegisteredUser<UserData> {
     pub fn delete(self) -> Result<()> {
         let certificates = self.all_certificates();
 
-        (&self.manager.users, &self.manager.certificates).transaction(|(tx_usr, tx_crt)| {
+        (&self.manager.users, &self.manager.certificates, &self.manager.usernames).transaction(|(tx_usr, tx_crt, tx_nam)| {
+            tx_nam.remove(
+                self.inner.username.as_str(),
+            )?;
             tx_usr.remove(
-                self.username.as_str(),
+                &self.uid.to_le_bytes(),
             )?;
             for cert in certificates {
                 tx_crt.remove(