diff --git a/Cargo.nix b/Cargo.nix
index c01222fe..fef82575 100644
--- a/Cargo.nix
+++ b/Cargo.nix
@@ -560,7 +560,7 @@ in
     registry = "registry+https://github.com/rust-lang/crates.io-index";
     src = fetchCratesIo { inherit name version; sha256 = "95059428f66df56b63431fdb4e1947ed2190586af5c5a8a8b71122bdf5a7f469"; };
     dependencies = {
-      ${ if hostPlatform.parsed.cpu.name == "aarch64" && hostPlatform.parsed.kernel.name == "linux" || hostPlatform.config == "aarch64-apple-darwin" then "libc" else null } = rustPackages."registry+https://github.com/rust-lang/crates.io-index".libc."0.2.115" { inherit profileName; };
+      ${ if hostPlatform.config == "aarch64-apple-darwin" || hostPlatform.parsed.cpu.name == "aarch64" && hostPlatform.parsed.kernel.name == "linux" then "libc" else null } = rustPackages."registry+https://github.com/rust-lang/crates.io-index".libc."0.2.103" { inherit profileName; };
     };
   });
   
@@ -672,6 +672,18 @@ in
       [ "default" ]
       [ "use_std" ]
     ];
+  "registry+https://github.com/rust-lang/crates.io-index".encoding_rs."0.8.30" = overridableMkRustCrate (profileName: rec {
+    name = "encoding_rs";
+    version = "0.8.30";
+    registry = "registry+https://github.com/rust-lang/crates.io-index";
+    src = fetchCratesIo { inherit name version; sha256 = "7896dc8abb250ffdda33912550faa54c88ec8b998dec0b2c55ab224921ce11df"; };
+    features = builtins.concatLists [
+      [ "alloc" ]
+      [ "default" ]
+    ];
+    dependencies = {
+      cfg_if = rustPackages."registry+https://github.com/rust-lang/crates.io-index".cfg-if."1.0.0" { inherit profileName; };
+    };
   });
   
   "registry+https://github.com/rust-lang/crates.io-index".env_logger."0.7.1" = overridableMkRustCrate (profileName: rec {
@@ -1014,6 +1026,7 @@ in
       idna = rustPackages."registry+https://github.com/rust-lang/crates.io-index".idna."0.2.3" { inherit profileName; };
       log = rustPackages."registry+https://github.com/rust-lang/crates.io-index".log."0.4.14" { inherit profileName; };
       md5 = rustPackages."registry+https://github.com/rust-lang/crates.io-index".md-5."0.9.1" { inherit profileName; };
+      multer = rustPackages."registry+https://github.com/rust-lang/crates.io-index".multer."2.0.2" { inherit profileName; };
       nom = rustPackages."registry+https://github.com/rust-lang/crates.io-index".nom."7.1.0" { inherit profileName; };
       percent_encoding = rustPackages."registry+https://github.com/rust-lang/crates.io-index".percent-encoding."2.1.0" { inherit profileName; };
       pin_project = rustPackages."registry+https://github.com/rust-lang/crates.io-index".pin-project."1.0.8" { inherit profileName; };
@@ -1021,6 +1034,7 @@ in
       roxmltree = rustPackages."registry+https://github.com/rust-lang/crates.io-index".roxmltree."0.14.1" { inherit profileName; };
       serde = rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde."1.0.130" { inherit profileName; };
       serde_bytes = rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde_bytes."0.11.5" { inherit profileName; };
+      serde_json = rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde_json."1.0.68" { inherit profileName; };
       sha2 = rustPackages."registry+https://github.com/rust-lang/crates.io-index".sha2."0.9.8" { inherit profileName; };
       tokio = rustPackages."registry+https://github.com/rust-lang/crates.io-index".tokio."1.12.0" { inherit profileName; };
       url = rustPackages."registry+https://github.com/rust-lang/crates.io-index".url."2.2.2" { inherit profileName; };
@@ -1768,6 +1782,13 @@ in
     };
   });
   
+  "registry+https://github.com/rust-lang/crates.io-index".mime."0.3.16" = overridableMkRustCrate (profileName: rec {
+    name = "mime";
+    version = "0.3.16";
+    registry = "registry+https://github.com/rust-lang/crates.io-index";
+    src = fetchCratesIo { inherit name version; sha256 = "2a60c7ce501c71e03a9c9c0d35b861413ae925bd979cc7a4e30d060069aaac8d"; };
+  });
+  
   "registry+https://github.com/rust-lang/crates.io-index".minimal-lexical."0.2.1" = overridableMkRustCrate (profileName: rec {
     name = "minimal-lexical";
     version = "0.2.1";
@@ -1812,6 +1833,30 @@ in
     };
   });
   
+  "registry+https://github.com/rust-lang/crates.io-index".multer."2.0.2" = overridableMkRustCrate (profileName: rec {
+    name = "multer";
+    version = "2.0.2";
+    registry = "registry+https://github.com/rust-lang/crates.io-index";
+    src = fetchCratesIo { inherit name version; sha256 = "5f8f35e687561d5c1667590911e6698a8cb714a134a7505718a182e7bc9d3836"; };
+    features = builtins.concatLists [
+      [ "default" ]
+    ];
+    dependencies = {
+      bytes = rustPackages."registry+https://github.com/rust-lang/crates.io-index".bytes."1.1.0" { inherit profileName; };
+      encoding_rs = rustPackages."registry+https://github.com/rust-lang/crates.io-index".encoding_rs."0.8.30" { inherit profileName; };
+      futures_util = rustPackages."registry+https://github.com/rust-lang/crates.io-index".futures-util."0.3.17" { inherit profileName; };
+      http = rustPackages."registry+https://github.com/rust-lang/crates.io-index".http."0.2.5" { inherit profileName; };
+      httparse = rustPackages."registry+https://github.com/rust-lang/crates.io-index".httparse."1.5.1" { inherit profileName; };
+      log = rustPackages."registry+https://github.com/rust-lang/crates.io-index".log."0.4.14" { inherit profileName; };
+      memchr = rustPackages."registry+https://github.com/rust-lang/crates.io-index".memchr."2.4.1" { inherit profileName; };
+      mime = rustPackages."registry+https://github.com/rust-lang/crates.io-index".mime."0.3.16" { inherit profileName; };
+      spin = rustPackages."registry+https://github.com/rust-lang/crates.io-index".spin."0.9.2" { inherit profileName; };
+    };
+    buildDependencies = {
+      version_check = buildRustPackages."registry+https://github.com/rust-lang/crates.io-index".version_check."0.9.3" { profileName = "__noProfile"; };
+    };
+  });
+  
   "registry+https://github.com/rust-lang/crates.io-index".netapp."0.3.0" = overridableMkRustCrate (profileName: rec {
     name = "netapp";
     version = "0.3.0";
@@ -2670,6 +2715,16 @@ in
     buildDependencies = {
       cfg_aliases = buildRustPackages."registry+https://github.com/rust-lang/crates.io-index".cfg_aliases."0.1.1" { profileName = "__noProfile"; };
     };
+
+  "registry+https://github.com/rust-lang/crates.io-index".spin."0.9.2" = overridableMkRustCrate (profileName: rec {
+    name = "spin";
+    version = "0.9.2";
+    registry = "registry+https://github.com/rust-lang/crates.io-index";
+    src = fetchCratesIo { inherit name version; sha256 = "511254be0c5bcf062b019a6c89c01a664aa359ded62f78aa72c6fc137c0590e5"; };
+    features = builtins.concatLists [
+      [ "mutex" ]
+      [ "spin_mutex" ]
+    ];
   });
   
   "registry+https://github.com/rust-lang/crates.io-index".structopt."0.3.23" = overridableMkRustCrate (profileName: rec {
diff --git a/src/api/s3_post_object.rs b/src/api/s3_post_object.rs
index 27c150b3..4f9003c8 100644
--- a/src/api/s3_post_object.rs
+++ b/src/api/s3_post_object.rs
@@ -113,13 +113,13 @@ pub async fn handle_post_object(
 		let key = if key.contains("${filename}") {
 			let filename = field.file_name();
 			// is this correct? Maybe we should error instead of default?
-			key.replace("${filename}", &filename.unwrap_or_default())
+			key.replace("${filename}", filename.unwrap_or_default())
 		} else {
 			key
 		};
 
 		// TODO verify scope against bucket&date?
-		let (key_id, scope) = parse_credential(&credential)?;
+		let (key_id, _scope) = parse_credential(&credential)?;
 		// TODO duplicated from signature/*
 		let date: NaiveDateTime = NaiveDateTime::parse_from_str(&date, LONG_DATETIME)
 			.ok_or_bad_request("invalid date")?;
@@ -202,9 +202,9 @@ pub async fn handle_post_object(
 		return Ok(resp);
 	}
 
-	return Err(Error::BadRequest(
+	Err(Error::BadRequest(
 		"Request did not contain a file".to_owned(),
-	));
+	))
 }
 
 // TODO remove allow(dead_code) when policy is verified