Rewrite entire codebase to split into client and server

src/server/input_sanitization.rs

@@ -0,0 +1,158 @@
+use crate::core::{
+    common::UnixUser,
+    protocol::server_responses::{NameValidationError, OwnerValidationError},
+};
+
+const MAX_NAME_LENGTH: usize = 64;
+
+pub fn validate_name(name: &str) -> Result<(), NameValidationError> {
+    if name.is_empty() {
+        Err(NameValidationError::EmptyString)
+    } else if name.len() > MAX_NAME_LENGTH {
+        Err(NameValidationError::TooLong)
+    } else if !name
+        .chars()
+        .all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '-')
+    {
+        Err(NameValidationError::InvalidCharacters)
+    } else {
+        Ok(())
+    }
+}
+
+pub fn validate_ownership_by_unix_user(
+    name: &str,
+    user: &UnixUser,
+) -> Result<(), OwnerValidationError> {
+    let prefixes = std::iter::once(user.username.clone())
+        .chain(user.groups.iter().cloned())
+        .collect::<Vec<String>>();
+
+    validate_ownership_by_prefixes(name, &prefixes)
+}
+
+/// Core logic for validating the ownership of a database name.
+/// This function checks if the given name matches any of the given prefixes.
+/// These prefixes will in most cases be the user's unix username and any
+/// unix groups the user is a member of.
+pub fn validate_ownership_by_prefixes(
+    name: &str,
+    prefixes: &[String],
+) -> Result<(), OwnerValidationError> {
+    if name.is_empty() {
+        return Err(OwnerValidationError::StringEmpty);
+    }
+
+    if name.starts_with('_') {
+        return Err(OwnerValidationError::MissingPrefix);
+    }
+
+    let (prefix, _) = match name.split_once('_') {
+        Some(pair) => pair,
+        None => return Err(OwnerValidationError::MissingPostfix),
+    };
+
+    if !prefixes.iter().any(|g| g == prefix) {
+        return Err(OwnerValidationError::NoMatch);
+    }
+
+    Ok(())
+}
+
+#[inline]
+pub fn quote_literal(s: &str) -> String {
+    format!("'{}'", s.replace('\'', r"\'"))
+}
+
+#[inline]
+pub fn quote_identifier(s: &str) -> String {
+    format!("`{}`", s.replace('`', r"\`"))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_quote_literal() {
+        let payload = "' OR 1=1 --";
+        assert_eq!(quote_literal(payload), r#"'\' OR 1=1 --'"#);
+    }
+
+    #[test]
+    fn test_quote_identifier() {
+        let payload = "` OR 1=1 --";
+        assert_eq!(quote_identifier(payload), r#"`\` OR 1=1 --`"#);
+    }
+
+    #[test]
+    fn test_validate_name() {
+        assert_eq!(validate_name(""), Err(NameValidationError::EmptyString));
+        assert_eq!(validate_name("abcdefghijklmnopqrstuvwxyz"), Ok(()));
+        assert_eq!(validate_name("ABCDEFGHIJKLMNOPQRSTUVWXYZ"), Ok(()));
+        assert_eq!(validate_name("0123456789_-"), Ok(()));
+
+        for c in "\n\t\r !@#$%^&*()+=[]{}|;:,.<>?/".chars() {
+            assert_eq!(
+                validate_name(&c.to_string()),
+                Err(NameValidationError::InvalidCharacters)
+            );
+        }
+
+        assert_eq!(validate_name(&"a".repeat(MAX_NAME_LENGTH)), Ok(()));
+
+        assert_eq!(
+            validate_name(&"a".repeat(MAX_NAME_LENGTH + 1)),
+            Err(NameValidationError::TooLong)
+        );
+    }
+
+    #[test]
+    fn test_validate_owner_by_prefixes() {
+        let prefixes = vec!["user".to_string(), "group".to_string()];
+
+        assert_eq!(
+            validate_ownership_by_prefixes("", &prefixes),
+            Err(OwnerValidationError::StringEmpty)
+        );
+
+        assert_eq!(
+            validate_ownership_by_prefixes("user", &prefixes),
+            Err(OwnerValidationError::MissingPostfix)
+        );
+        assert_eq!(
+            validate_ownership_by_prefixes("something", &prefixes),
+            Err(OwnerValidationError::MissingPostfix)
+        );
+        assert_eq!(
+            validate_ownership_by_prefixes("user-testdb", &prefixes),
+            Err(OwnerValidationError::MissingPostfix)
+        );
+
+        assert_eq!(
+            validate_ownership_by_prefixes("_testdb", &prefixes),
+            Err(OwnerValidationError::MissingPrefix)
+        );
+
+        assert_eq!(
+            validate_ownership_by_prefixes("user_testdb", &prefixes),
+            Ok(())
+        );
+        assert_eq!(
+            validate_ownership_by_prefixes("group_testdb", &prefixes),
+            Ok(())
+        );
+        assert_eq!(
+            validate_ownership_by_prefixes("group_test_db", &prefixes),
+            Ok(())
+        );
+        assert_eq!(
+            validate_ownership_by_prefixes("group_test-db", &prefixes),
+            Ok(())
+        );
+
+        assert_eq!(
+            validate_ownership_by_prefixes("nonexistent_testdb", &prefixes),
+            Err(OwnerValidationError::NoMatch)
+        );
+    }
+}