fix(admin): percent-decode group name in DELETE /v3/group/{group} (#2358)

Co-authored-by: GatewayJ <8352692332qq.com>

crates/checksums/src/lib.rs

@@ -349,7 +349,7 @@ mod tests {
     fn base64_encoded_checksum_to_hex_string(header_value: &HeaderValue) -> String {
         let decoded_checksum = base64::decode(header_value.to_str().unwrap()).unwrap();
         let decoded_checksum = decoded_checksum.into_iter().fold(String::new(), |mut acc, byte| {
-            write!(acc, "{byte:02X?}").expect("string will always be writeable");
+            write!(acc, "{byte:02X?}").expect("string will always be writable");
             acc
         });
 

rustfs/src/admin/handlers/group.rs

@@ -25,6 +25,7 @@ use crate::{
 use http::{HeaderMap, StatusCode};
 use hyper::Method;
 use matchit::Params;
+use percent_encoding::percent_decode_str;
 use rustfs_config::MAX_ADMIN_REQUEST_BODY_SIZE;
 use rustfs_credentials::get_global_action_cred;
 use rustfs_iam::error::{is_err_no_such_group, is_err_no_such_user};
@@ -206,11 +207,17 @@ impl Operation for DeleteGroup {
         )
         .await?;
 
-        let group = params
+        let group_raw = params
             .get("group")
             .ok_or_else(|| s3_error!(InvalidArgument, "missing group name in request"))?
             .trim();
 
+        // Path segments stay percent-encoded in `req.uri.path()` / matchit; IAM uses decoded names (same as GET query).
+        let group_decoded = percent_decode_str(group_raw)
+            .decode_utf8()
+            .map_err(|_| s3_error!(InvalidArgument, "invalid group name encoding"))?;
+        let group = group_decoded.trim();
+
         // Validate the group name format
         if group.is_empty() || group.len() > 256 {
             return Err(s3_error!(InvalidArgument, "invalid group name"));