diff --git a/src/api/encoding.rs b/src/api/encoding.rs
index b3fbbe3..e286a78 100644
--- a/src/api/encoding.rs
+++ b/src/api/encoding.rs
@@ -1,13 +1,5 @@
 //! Module containing various helpers for encoding
 
-/// Escape &str for xml inclusion
-pub fn xml_escape(s: &str) -> String {
-	s.replace("&", "&")
-		.replace("<", "&lt;")
-		.replace(">", "&gt;")
-		.replace("\"", "&quot;")
-}
-
 /// Encode &str for use in a URI
 pub fn uri_encode(string: &str, encode_slash: bool) -> String {
 	let mut result = String::with_capacity(string.len() * 2);
@@ -28,12 +20,3 @@ pub fn uri_encode(string: &str, encode_slash: bool) -> String {
 	}
 	result
 }
-
-/// Encode &str either as an uri, or a valid string for xml inclusion
-pub fn xml_encode_key(k: &str, urlencode: bool) -> String {
-	if urlencode {
-		uri_encode(k, true)
-	} else {
-		xml_escape(k)
-	}
-}
diff --git a/src/api/error.rs b/src/api/error.rs
index a49ba21..7d97366 100644
--- a/src/api/error.rs
+++ b/src/api/error.rs
@@ -1,11 +1,9 @@
-use std::fmt::Write;
-
 use err_derive::Error;
 use hyper::StatusCode;
 
 use garage_util::error::Error as GarageError;
 
-use crate::encoding::*;
+use crate::s3_xml;
 
 /// Errors of this crate
 #[derive(Debug, Error)]
@@ -104,15 +102,22 @@ impl Error {
 	}
 
 	pub fn aws_xml(&self, garage_region: &str, path: &str) -> String {
-		let mut xml = String::new();
-		writeln!(&mut xml, r#"<?xml version="1.0" encoding="UTF-8"?>"#).unwrap();
-		writeln!(&mut xml, "<Error>").unwrap();
-		writeln!(&mut xml, "\t<Code>{}</Code>", self.aws_code()).unwrap();
-		writeln!(&mut xml, "\t<Message>{}</Message>", self).unwrap();
-		writeln!(&mut xml, "\t<Resource>{}</Resource>", xml_escape(path)).unwrap();
-		writeln!(&mut xml, "\t<Region>{}</Region>", garage_region).unwrap();
-		writeln!(&mut xml, "</Error>").unwrap();
-		xml
+		let error = s3_xml::Error {
+			code: s3_xml::Value(self.aws_code().to_string()),
+			message: s3_xml::Value(format!("{}", self)),
+			resource: Some(s3_xml::Value(path.to_string())),
+			region: Some(s3_xml::Value(garage_region.to_string())),
+		};
+		s3_xml::to_xml_with_header(&error).unwrap_or_else(|_| {
+			r#"
+<?xml version="1.0" encoding="UTF-8"?>
+<Error>
+	<Code>InternalError</Code>
+	<Message>XML encoding of error failed</Message>
+</Error>
+			"#
+			.into()
+		})
 	}
 }
 
diff --git a/src/api/lib.rs b/src/api/lib.rs
index 6c6447d..9a23c23 100644
--- a/src/api/lib.rs
+++ b/src/api/lib.rs
@@ -18,3 +18,4 @@ mod s3_delete;
 pub mod s3_get;
 mod s3_list;
 mod s3_put;
+mod s3_xml;
diff --git a/src/api/s3_bucket.rs b/src/api/s3_bucket.rs
index e7d8969..88d13ca 100644
--- a/src/api/s3_bucket.rs
+++ b/src/api/s3_bucket.rs
@@ -1,73 +1,20 @@
-use std::fmt::Write;
 use std::sync::Arc;
 
 use hyper::{Body, Response};
-use quick_xml::se::to_string;
-use serde::Serialize;
 
 use garage_model::garage::Garage;
 use garage_model::key_table::Key;
 use garage_util::time::*;
 
 use crate::error::*;
-
-#[derive(Debug, Serialize, PartialEq)]
-struct CreationDate {
-	#[serde(rename = "$value")]
-	pub body: String,
-}
-#[derive(Debug, Serialize, PartialEq)]
-struct Name {
-	#[serde(rename = "$value")]
-	pub body: String,
-}
-#[derive(Debug, Serialize, PartialEq)]
-struct Bucket {
-	#[serde(rename = "CreationDate")]
-	pub creation_date: CreationDate,
-	#[serde(rename = "Name")]
-	pub name: Name,
-}
-#[derive(Debug, Serialize, PartialEq)]
-struct DisplayName {
-	#[serde(rename = "$value")]
-	pub body: String,
-}
-#[derive(Debug, Serialize, PartialEq)]
-struct Id {
-	#[serde(rename = "$value")]
-	pub body: String,
-}
-#[derive(Debug, Serialize, PartialEq)]
-struct Owner {
-	#[serde(rename = "DisplayName")]
-	display_name: DisplayName,
-	#[serde(rename = "ID")]
-	id: Id,
-}
-#[derive(Debug, Serialize, PartialEq)]
-struct BucketList {
-	#[serde(rename = "Bucket")]
-	pub entries: Vec<Bucket>,
-}
-#[derive(Debug, Serialize, PartialEq)]
-struct ListAllMyBucketsResult {
-	#[serde(rename = "Buckets")]
-	buckets: BucketList,
-	#[serde(rename = "Owner")]
-	owner: Owner,
-}
+use crate::s3_xml;
 
 pub fn handle_get_bucket_location(garage: Arc<Garage>) -> Result<Response<Body>, Error> {
-	let mut xml = String::new();
-
-	writeln!(&mut xml, r#"<?xml version="1.0" encoding="UTF-8"?>"#).unwrap();
-	writeln!(
-		&mut xml,
-		r#"<LocationConstraint xmlns="http://s3.amazonaws.com/doc/2006-03-01/">{}</LocationConstraint>"#,
-		garage.config.s3_api.s3_region
-	)
-	.unwrap();
+	let loc = s3_xml::LocationConstraint {
+		xmlns: (),
+		region: garage.config.s3_api.s3_region.to_string(),
+	};
+	let xml = s3_xml::to_xml_with_header(&loc)?;
 
 	Ok(Response::builder()
 		.header("Content-Type", "application/xml")
@@ -75,34 +22,25 @@ pub fn handle_get_bucket_location(garage: Arc<Garage>) -> Result<Response<Body>,
 }
 
 pub fn handle_list_buckets(api_key: &Key) -> Result<Response<Body>, Error> {
-	let list_buckets = ListAllMyBucketsResult {
-		owner: Owner {
-			display_name: DisplayName {
-				body: api_key.name.get().to_string(),
-			},
-			id: Id {
-				body: api_key.key_id.to_string(),
-			},
+	let list_buckets = s3_xml::ListAllMyBucketsResult {
+		owner: s3_xml::Owner {
+			display_name: s3_xml::Value(api_key.name.get().to_string()),
+			id: s3_xml::Value(api_key.key_id.to_string()),
 		},
-		buckets: BucketList {
+		buckets: s3_xml::BucketList {
 			entries: api_key
 				.authorized_buckets
 				.items()
 				.iter()
-				.map(|(name, ts, _)| Bucket {
-					creation_date: CreationDate {
-						body: msec_to_rfc3339(*ts),
-					},
-					name: Name {
-						body: name.to_string(),
-					},
+				.map(|(name, ts, _)| s3_xml::Bucket {
+					creation_date: s3_xml::Value(msec_to_rfc3339(*ts)),
+					name: s3_xml::Value(name.to_string()),
 				})
 				.collect(),
 		},
 	};
 
-	let mut xml = r#"<?xml version="1.0" encoding="UTF-8"?>"#.to_string();
-	xml.push_str(&to_string(&list_buckets)?);
+	let xml = s3_xml::to_xml_with_header(&list_buckets)?;
 	trace!("xml: {}", xml);
 
 	Ok(Response::builder()
diff --git a/src/api/s3_copy.rs b/src/api/s3_copy.rs
index 7069489..9ade698 100644
--- a/src/api/s3_copy.rs
+++ b/src/api/s3_copy.rs
@@ -1,4 +1,3 @@
-use std::fmt::Write;
 use std::sync::Arc;
 
 use hyper::{Body, Request, Response};
@@ -14,6 +13,7 @@ use garage_model::version_table::*;
 
 use crate::error::*;
 use crate::s3_put::get_headers;
+use crate::s3_xml;
 
 pub async fn handle_copy(
 	garage: Arc<Garage>,
@@ -61,6 +61,8 @@ pub async fn handle_copy(
 		_ => old_meta.clone(),
 	};
 
+	let etag = new_meta.etag.to_string();
+
 	// Save object copy
 	match source_last_state {
 		ObjectVersionData::DeleteMarker => unreachable!(),
@@ -158,13 +160,13 @@ pub async fn handle_copy(
 	}
 
 	let last_modified = msec_to_rfc3339(new_timestamp);
-	let mut xml = String::new();
-	writeln!(&mut xml, r#"<?xml version="1.0" encoding="UTF-8"?>"#).unwrap();
-	writeln!(&mut xml, r#"<CopyObjectResult>"#).unwrap();
-	writeln!(&mut xml, "\t<LastModified>{}</LastModified>", last_modified).unwrap();
-	writeln!(&mut xml, "</CopyObjectResult>").unwrap();
+	let result = s3_xml::CopyObjectResult {
+		last_modified: s3_xml::Value(last_modified),
+		etag: s3_xml::Value(etag),
+	};
+	let xml = s3_xml::to_xml_with_header(&result)?;
 
 	Ok(Response::builder()
 		.header("Content-Type", "application/xml")
-		.body(Body::from(xml.into_bytes()))?)
+		.body(Body::from(xml))?)
 }
diff --git a/src/api/s3_delete.rs b/src/api/s3_delete.rs
index 9d2a67f..a391a33 100644
--- a/src/api/s3_delete.rs
+++ b/src/api/s3_delete.rs
@@ -1,4 +1,3 @@
-use std::fmt::Write;
 use std::sync::Arc;
 
 use hyper::{Body, Request, Response};
@@ -9,8 +8,8 @@ use garage_util::time::*;
 use garage_model::garage::Garage;
 use garage_model::object_table::*;
 
-use crate::encoding::*;
 use crate::error::*;
+use crate::s3_xml;
 use crate::signature::verify_signed_content;
 
 async fn handle_delete_internal(
@@ -85,13 +84,8 @@ pub async fn handle_delete_objects(
 	let cmd_xml = roxmltree::Document::parse(&std::str::from_utf8(&body)?)?;
 	let cmd = parse_delete_objects_xml(&cmd_xml).ok_or_bad_request("Invalid delete XML query")?;
 
-	let mut retxml = String::new();
-	writeln!(&mut retxml, r#"<?xml version="1.0" encoding="UTF-8"?>"#).unwrap();
-	writeln!(
-		&mut retxml,
-		r#"<DeleteResult xmlns="http://s3.amazonaws.com/doc/2006-03-01/">"#
-	)
-	.unwrap();
+	let mut ret_deleted = Vec::new();
+	let mut ret_errors = Vec::new();
 
 	for obj in cmd.objects.iter() {
 		match handle_delete_internal(&garage, bucket, &obj.key).await {
@@ -99,42 +93,32 @@ pub async fn handle_delete_objects(
 				if cmd.quiet {
 					continue;
 				}
-				writeln!(&mut retxml, "\t<Deleted>").unwrap();
-				writeln!(&mut retxml, "\t\t<Key>{}</Key>", xml_escape(&obj.key)).unwrap();
-				writeln!(
-					&mut retxml,
-					"\t\t<VersionId>{}</VersionId>",
-					hex::encode(deleted_version)
-				)
-				.unwrap();
-				writeln!(
-					&mut retxml,
-					"\t\t<DeleteMarkerVersionId>{}</DeleteMarkerVersionId>",
-					hex::encode(delete_marker_version)
-				)
-				.unwrap();
-				writeln!(&mut retxml, "\t</Deleted>").unwrap();
+				ret_deleted.push(s3_xml::Deleted {
+					key: s3_xml::Value(obj.key.clone()),
+					version_id: s3_xml::Value(hex::encode(deleted_version)),
+					delete_marker_version_id: s3_xml::Value(hex::encode(delete_marker_version)),
+				});
 			}
 			Err(e) => {
-				writeln!(&mut retxml, "\t<Error>").unwrap();
-				writeln!(&mut retxml, "\t\t<Code>{}</Code>", e.http_status_code()).unwrap();
-				writeln!(&mut retxml, "\t\t<Key>{}</Key>", xml_escape(&obj.key)).unwrap();
-				writeln!(
-					&mut retxml,
-					"\t\t<Message>{}</Message>",
-					xml_escape(&format!("{}", e))
-				)
-				.unwrap();
-				writeln!(&mut retxml, "\t</Error>").unwrap();
+				ret_errors.push(s3_xml::DeleteError {
+					code: s3_xml::Value(e.aws_code().to_string()),
+					key: Some(s3_xml::Value(obj.key.clone())),
+					message: s3_xml::Value(format!("{}", e)),
+					version_id: None,
+				});
 			}
 		}
 	}
 
-	writeln!(&mut retxml, "</DeleteResult>").unwrap();
+	let xml = s3_xml::to_xml_with_header(&s3_xml::DeleteResult {
+		xmlns: (),
+		deleted: ret_deleted,
+		errors: ret_errors,
+	})?;
 
 	Ok(Response::builder()
 		.header("Content-Type", "application/xml")
-		.body(Body::from(retxml.into_bytes()))?)
+		.body(Body::from(xml))?)
 }
 
 struct DeleteRequest {
diff --git a/src/api/s3_list.rs b/src/api/s3_list.rs
index 80fefd5..384346e 100644
--- a/src/api/s3_list.rs
+++ b/src/api/s3_list.rs
@@ -1,5 +1,4 @@
 use std::collections::{BTreeMap, BTreeSet, HashMap};
-use std::fmt::Write;
 use std::sync::Arc;
 
 use hyper::{Body, Response};
@@ -14,6 +13,7 @@ use garage_table::DeletedFilter;
 
 use crate::encoding::*;
 use crate::error::*;
+use crate::s3_xml;
 
 #[derive(Debug)]
 pub struct ListObjectsQuery {
@@ -163,126 +163,81 @@ pub async fn handle_list(
 		}
 	}
 
-	let mut xml = String::new();
-	writeln!(&mut xml, r#"<?xml version="1.0" encoding="UTF-8"?>"#).unwrap();
-	writeln!(
-		&mut xml,
-		r#"<ListBucketResult xmlns="http://s3.amazonaws.com/doc/2006-03-01/">"#
-	)
-	.unwrap();
+	let mut result = s3_xml::ListBucketResult {
+		xmlns: (),
+		name: s3_xml::Value(query.bucket.to_string()),
+		prefix: uriencode_maybe(&query.prefix, query.urlencode_resp),
+		marker: None,
+		next_marker: None,
+		start_after: None,
+		continuation_token: None,
+		next_continuation_token: None,
+		max_keys: s3_xml::IntValue(query.max_keys as i64),
+		delimiter: query
+			.delimiter
+			.as_ref()
+			.map(|x| uriencode_maybe(x, query.urlencode_resp)),
+		encoding_type: match query.urlencode_resp {
+			true => Some(s3_xml::Value("url".to_string())),
+			false => None,
+		},
 
-	writeln!(&mut xml, "\t<Name>{}</Name>", query.bucket).unwrap();
-
-	// TODO: in V1, is this supposed to be urlencoded when encoding-type is URL??
-	writeln!(
-		&mut xml,
-		"\t<Prefix>{}</Prefix>",
-		xml_encode_key(&query.prefix, query.urlencode_resp),
-	)
-	.unwrap();
-
-	if let Some(delim) = &query.delimiter {
-		// TODO: in V1, is this supposed to be urlencoded when encoding-type is URL??
-		writeln!(
-			&mut xml,
-			"\t<Delimiter>{}</Delimiter>",
-			xml_encode_key(delim, query.urlencode_resp),
-		)
-		.unwrap();
-	}
-
-	writeln!(&mut xml, "\t<MaxKeys>{}</MaxKeys>", query.max_keys).unwrap();
-	if query.urlencode_resp {
-		writeln!(&mut xml, "\t<EncodingType>url</EncodingType>").unwrap();
-	}
-
-	writeln!(
-		&mut xml,
-		"\t<KeyCount>{}</KeyCount>",
-		result_keys.len() + result_common_prefixes.len()
-	)
-	.unwrap();
-	writeln!(
-		&mut xml,
-		"\t<IsTruncated>{}</IsTruncated>",
-		truncated.is_some()
-	)
-	.unwrap();
+		key_count: Some(s3_xml::IntValue(
+			result_keys.len() as i64 + result_common_prefixes.len() as i64,
+		)),
+		is_truncated: s3_xml::Value(format!("{}", truncated.is_some())),
+		contents: vec![],
+		common_prefixes: vec![],
+	};
 
 	if query.is_v2 {
 		if let Some(ct) = &query.continuation_token {
-			writeln!(&mut xml, "\t<ContinuationToken>{}</ContinuationToken>", ct).unwrap();
+			result.continuation_token = Some(s3_xml::Value(ct.to_string()));
 		}
 		if let Some(sa) = &query.start_after {
-			writeln!(
-				&mut xml,
-				"\t<StartAfter>{}</StartAfter>",
-				xml_encode_key(sa, query.urlencode_resp)
-			)
-			.unwrap();
+			result.start_after = Some(uriencode_maybe(sa, query.urlencode_resp));
 		}
 		if let Some(nct) = truncated {
-			writeln!(
-				&mut xml,
-				"\t<NextContinuationToken>{}</NextContinuationToken>",
-				base64::encode(nct.as_bytes())
-			)
-			.unwrap();
+			result.next_continuation_token = Some(s3_xml::Value(base64::encode(nct.as_bytes())));
 		}
 	} else {
 		// TODO: are these supposed to be urlencoded when encoding-type is URL??
 		if let Some(mkr) = &query.marker {
-			writeln!(
-				&mut xml,
-				"\t<Marker>{}</Marker>",
-				xml_encode_key(mkr, query.urlencode_resp)
-			)
-			.unwrap();
+			result.marker = Some(uriencode_maybe(mkr, query.urlencode_resp));
 		}
 		if let Some(next_marker) = truncated {
-			writeln!(
-				&mut xml,
-				"\t<NextMarker>{}</NextMarker>",
-				xml_encode_key(&next_marker, query.urlencode_resp)
-			)
-			.unwrap();
+			result.next_marker = Some(uriencode_maybe(&next_marker, query.urlencode_resp));
 		}
 	}
 
 	for (key, info) in result_keys.iter() {
-		let last_modif = msec_to_rfc3339(info.last_modified);
-		writeln!(&mut xml, "\t<Contents>").unwrap();
-		writeln!(
-			&mut xml,
-			"\t\t<Key>{}</Key>",
-			xml_encode_key(key, query.urlencode_resp),
-		)
-		.unwrap();
-		writeln!(&mut xml, "\t\t<LastModified>{}</LastModified>", last_modif).unwrap();
-		writeln!(&mut xml, "\t\t<Size>{}</Size>", info.size).unwrap();
-		if !info.etag.is_empty() {
-			writeln!(&mut xml, "\t\t<ETag>\"{}\"</ETag>", info.etag).unwrap();
-		}
-		writeln!(&mut xml, "\t\t<StorageClass>STANDARD</StorageClass>").unwrap();
-		writeln!(&mut xml, "\t</Contents>").unwrap();
+		result.contents.push(s3_xml::ListBucketItem {
+			key: uriencode_maybe(key, query.urlencode_resp),
+			last_modified: s3_xml::Value(msec_to_rfc3339(info.last_modified)),
+			size: s3_xml::IntValue(info.size as i64),
+			etag: s3_xml::Value(info.etag.to_string()),
+			storage_class: s3_xml::Value("STANDARD".to_string()),
+		});
 	}
 
 	for pfx in result_common_prefixes.iter() {
-		writeln!(&mut xml, "\t<CommonPrefixes>").unwrap();
 		//TODO: in V1, are these urlencoded when urlencode_resp is true ?? (proably)
-		writeln!(
-			&mut xml,
-			"\t\t<Prefix>{}</Prefix>",
-			xml_encode_key(pfx, query.urlencode_resp),
-		)
-		.unwrap();
-		writeln!(&mut xml, "\t</CommonPrefixes>").unwrap();
+		result.common_prefixes.push(s3_xml::CommonPrefix {
+			prefix: uriencode_maybe(pfx, query.urlencode_resp),
+		});
 	}
 
-	writeln!(&mut xml, "</ListBucketResult>").unwrap();
-	debug!("{}", xml);
+	let xml = s3_xml::to_xml_with_header(&result)?;
 
 	Ok(Response::builder()
 		.header("Content-Type", "application/xml")
 		.body(Body::from(xml.into_bytes()))?)
 }
+
+fn uriencode_maybe(s: &str, yes: bool) -> s3_xml::Value {
+	if yes {
+		s3_xml::Value(uri_encode(s, true))
+	} else {
+		s3_xml::Value(s.to_string())
+	}
+}
diff --git a/src/api/s3_put.rs b/src/api/s3_put.rs
index bb6cf57..aa28523 100644
--- a/src/api/s3_put.rs
+++ b/src/api/s3_put.rs
@@ -1,5 +1,4 @@
 use std::collections::{BTreeMap, VecDeque};
-use std::fmt::Write;
 use std::sync::Arc;
 
 use futures::stream::*;
@@ -18,8 +17,8 @@ use garage_model::garage::Garage;
 use garage_model::object_table::*;
 use garage_model::version_table::*;
 
-use crate::encoding::*;
 use crate::error::*;
+use crate::s3_xml;
 use crate::signature::verify_signed_content;
 
 pub async fn handle_put(
@@ -339,22 +338,13 @@ pub async fn handle_create_multipart_upload(
 	garage.version_table.insert(&version).await?;
 
 	// Send success response
-	let mut xml = String::new();
-	writeln!(&mut xml, r#"<?xml version="1.0" encoding="UTF-8"?>"#).unwrap();
-	writeln!(
-		&mut xml,
-		r#"<InitiateMultipartUploadResult xmlns="http://s3.amazonaws.com/doc/2006-03-01/">"#
-	)
-	.unwrap();
-	writeln!(&mut xml, "\t<Bucket>{}</Bucket>", bucket).unwrap();
-	writeln!(&mut xml, "\t<Key>{}</Key>", xml_escape(key)).unwrap();
-	writeln!(
-		&mut xml,
-		"\t<UploadId>{}</UploadId>",
-		hex::encode(version_uuid)
-	)
-	.unwrap();
-	writeln!(&mut xml, "</InitiateMultipartUploadResult>").unwrap();
+	let result = s3_xml::InitiateMultipartUploadResult {
+		xmlns: (),
+		bucket: s3_xml::Value(bucket.to_string()),
+		key: s3_xml::Value(key.to_string()),
+		upload_id: s3_xml::Value(hex::encode(version_uuid)),
+	};
+	let xml = s3_xml::to_xml_with_header(&result)?;
 
 	Ok(Response::new(Body::from(xml.into_bytes())))
 }
@@ -520,7 +510,7 @@ pub async fn handle_complete_multipart_upload(
 		ObjectVersionMeta {
 			headers,
 			size: total_size,
-			etag,
+			etag: etag.clone(),
 		},
 		version.blocks.items()[0].1.hash,
 	));
@@ -529,22 +519,14 @@ pub async fn handle_complete_multipart_upload(
 	garage.object_table.insert(&final_object).await?;
 
 	// Send response saying ok we're done
-	let mut xml = String::new();
-	writeln!(&mut xml, r#"<?xml version="1.0" encoding="UTF-8"?>"#).unwrap();
-	writeln!(
-		&mut xml,
-		r#"<CompleteMultipartUploadResult xmlns="http://s3.amazonaws.com/doc/2006-03-01/">"#
-	)
-	.unwrap();
-	writeln!(
-		&mut xml,
-		"\t<Location>{}</Location>",
-		garage.config.s3_api.s3_region
-	)
-	.unwrap();
-	writeln!(&mut xml, "\t<Bucket>{}</Bucket>", bucket).unwrap();
-	writeln!(&mut xml, "\t<Key>{}</Key>", xml_escape(&key)).unwrap();
-	writeln!(&mut xml, "</CompleteMultipartUploadResult>").unwrap();
+	let result = s3_xml::CompleteMultipartUploadResult {
+		xmlns: (),
+		location: None,
+		bucket: s3_xml::Value(bucket),
+		key: s3_xml::Value(key),
+		etag: s3_xml::Value(etag),
+	};
+	let xml = s3_xml::to_xml_with_header(&result)?;
 
 	Ok(Response::new(Body::from(xml.into_bytes())))
 }
diff --git a/src/api/s3_xml.rs b/src/api/s3_xml.rs
new file mode 100644
index 0000000..ba9b908
--- /dev/null
+++ b/src/api/s3_xml.rs
@@ -0,0 +1,597 @@
+use quick_xml::se::to_string;
+use serde::{Serialize, Serializer};
+
+use crate::Error as ApiError;
+
+pub fn to_xml_with_header<T: Serialize>(x: &T) -> Result<String, ApiError> {
+	let mut xml = r#"<?xml version="1.0" encoding="UTF-8"?>"#.to_string();
+	xml.push_str(&to_string(x)?);
+	Ok(xml)
+}
+
+fn xmlns_tag<S: Serializer>(_v: &(), s: S) -> Result<S::Ok, S::Error> {
+	s.serialize_str("http://s3.amazonaws.com/doc/2006-03-01/")
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct Value(#[serde(rename = "$value")] pub String);
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct IntValue(#[serde(rename = "$value")] pub i64);
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct Bucket {
+	#[serde(rename = "CreationDate")]
+	pub creation_date: Value,
+	#[serde(rename = "Name")]
+	pub name: Value,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct DisplayName(#[serde(rename = "$value")] pub String);
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct Id(#[serde(rename = "$value")] pub String);
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct Owner {
+	#[serde(rename = "DisplayName")]
+	pub display_name: Value,
+	#[serde(rename = "ID")]
+	pub id: Value,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct BucketList {
+	#[serde(rename = "Bucket")]
+	pub entries: Vec<Bucket>,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct ListAllMyBucketsResult {
+	#[serde(rename = "Buckets")]
+	pub buckets: BucketList,
+	#[serde(rename = "Owner")]
+	pub owner: Owner,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct LocationConstraint {
+	#[serde(serialize_with = "xmlns_tag")]
+	pub xmlns: (),
+	#[serde(rename = "$value")]
+	pub region: String,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct Deleted {
+	#[serde(rename = "Key")]
+	pub key: Value,
+	#[serde(rename = "VersionId")]
+	pub version_id: Value,
+	#[serde(rename = "DeleteMarkerVersionId")]
+	pub delete_marker_version_id: Value,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct Error {
+	#[serde(rename = "Code")]
+	pub code: Value,
+	#[serde(rename = "Message")]
+	pub message: Value,
+	#[serde(rename = "Resource")]
+	pub resource: Option<Value>,
+	#[serde(rename = "Region")]
+	pub region: Option<Value>,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct DeleteError {
+	#[serde(rename = "Code")]
+	pub code: Value,
+	#[serde(rename = "Key")]
+	pub key: Option<Value>,
+	#[serde(rename = "Message")]
+	pub message: Value,
+	#[serde(rename = "VersionId")]
+	pub version_id: Option<Value>,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct DeleteResult {
+	#[serde(serialize_with = "xmlns_tag")]
+	pub xmlns: (),
+	#[serde(rename = "Deleted")]
+	pub deleted: Vec<Deleted>,
+	#[serde(rename = "Error")]
+	pub errors: Vec<DeleteError>,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct CopyObjectResult {
+	#[serde(rename = "LastModified")]
+	pub last_modified: Value,
+	#[serde(rename = "ETag")]
+	pub etag: Value,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct InitiateMultipartUploadResult {
+	#[serde(serialize_with = "xmlns_tag")]
+	pub xmlns: (),
+	#[serde(rename = "Bucket")]
+	pub bucket: Value,
+	#[serde(rename = "Key")]
+	pub key: Value,
+	#[serde(rename = "UploadId")]
+	pub upload_id: Value,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct CompleteMultipartUploadResult {
+	#[serde(serialize_with = "xmlns_tag")]
+	pub xmlns: (),
+	#[serde(rename = "Location")]
+	pub location: Option<Value>,
+	#[serde(rename = "Bucket")]
+	pub bucket: Value,
+	#[serde(rename = "Key")]
+	pub key: Value,
+	#[serde(rename = "ETag")]
+	pub etag: Value,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct ListBucketItem {
+	#[serde(rename = "Key")]
+	pub key: Value,
+	#[serde(rename = "LastModified")]
+	pub last_modified: Value,
+	#[serde(rename = "ETag")]
+	pub etag: Value,
+	#[serde(rename = "Size")]
+	pub size: IntValue,
+	#[serde(rename = "StorageClass")]
+	pub storage_class: Value,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct CommonPrefix {
+	#[serde(rename = "Prefix")]
+	pub prefix: Value,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct ListBucketResult {
+	#[serde(serialize_with = "xmlns_tag")]
+	pub xmlns: (),
+	#[serde(rename = "Name")]
+	pub name: Value,
+	#[serde(rename = "Prefix")]
+	pub prefix: Value,
+	#[serde(rename = "Marker")]
+	pub marker: Option<Value>,
+	#[serde(rename = "NextMarker")]
+	pub next_marker: Option<Value>,
+	#[serde(rename = "StartAfter")]
+	pub start_after: Option<Value>,
+	#[serde(rename = "ContinuationToken")]
+	pub continuation_token: Option<Value>,
+	#[serde(rename = "NextContinuationToken")]
+	pub next_continuation_token: Option<Value>,
+	#[serde(rename = "KeyCount")]
+	pub key_count: Option<IntValue>,
+	#[serde(rename = "MaxKeys")]
+	pub max_keys: IntValue,
+	#[serde(rename = "Delimiter")]
+	pub delimiter: Option<Value>,
+	#[serde(rename = "EncodingType")]
+	pub encoding_type: Option<Value>,
+	#[serde(rename = "IsTruncated")]
+	pub is_truncated: Value,
+	#[serde(rename = "Contents")]
+	pub contents: Vec<ListBucketItem>,
+	#[serde(rename = "CommonPrefixes")]
+	pub common_prefixes: Vec<CommonPrefix>,
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	use garage_util::time::*;
+
+	#[test]
+	fn error_message() -> Result<(), ApiError> {
+		let error = Error {
+			code: Value("TestError".to_string()),
+			message: Value("A dummy error message".to_string()),
+			resource: Some(Value("/bucket/a/plop".to_string())),
+			region: Some(Value("garage".to_string())),
+		};
+		assert_eq!(
+			to_xml_with_header(&error)?,
+			"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\
+<Error>\
+	<Code>TestError</Code>\
+	<Message>A dummy error message</Message>\
+	<Resource>/bucket/a/plop</Resource>\
+	<Region>garage</Region>\
+</Error>"
+		);
+		Ok(())
+	}
+
+	#[test]
+	fn list_all_my_buckets_result() -> Result<(), ApiError> {
+		let list_buckets = ListAllMyBucketsResult {
+			owner: Owner {
+				display_name: Value("owner_name".to_string()),
+				id: Value("qsdfjklm".to_string()),
+			},
+			buckets: BucketList {
+				entries: vec![
+					Bucket {
+						creation_date: Value(msec_to_rfc3339(0)),
+						name: Value("bucket_A".to_string()),
+					},
+					Bucket {
+						creation_date: Value(msec_to_rfc3339(3600 * 24 * 1000)),
+						name: Value("bucket_B".to_string()),
+					},
+				],
+			},
+		};
+		assert_eq!(
+			to_xml_with_header(&list_buckets)?,
+			"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\
+<ListAllMyBucketsResult>\
+   <Buckets>\
+      <Bucket>\
+         <CreationDate>1970-01-01T00:00:00.000Z</CreationDate>\
+         <Name>bucket_A</Name>\
+      </Bucket>\
+      <Bucket>\
+         <CreationDate>1970-01-02T00:00:00.000Z</CreationDate>\
+         <Name>bucket_B</Name>\
+      </Bucket>\
+   </Buckets>\
+   <Owner>\
+      <DisplayName>owner_name</DisplayName>\
+      <ID>qsdfjklm</ID>\
+   </Owner>\
+</ListAllMyBucketsResult>"
+		);
+		Ok(())
+	}
+
+	#[test]
+	fn get_bucket_location_result() -> Result<(), ApiError> {
+		let get_bucket_location = LocationConstraint {
+			xmlns: (),
+			region: "garage".to_string(),
+		};
+		assert_eq!(
+			to_xml_with_header(&get_bucket_location)?,
+			"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\
+<LocationConstraint xmlns=\"http://s3.amazonaws.com/doc/2006-03-01/\">garage</LocationConstraint>"
+		);
+		Ok(())
+	}
+
+	#[test]
+	fn delete_result() -> Result<(), ApiError> {
+		let delete_result = DeleteResult {
+			xmlns: (),
+			deleted: vec![
+				Deleted {
+					key: Value("a/plop".to_string()),
+					version_id: Value("qsdfjklm".to_string()),
+					delete_marker_version_id: Value("wxcvbn".to_string()),
+				},
+				Deleted {
+					key: Value("b/plip".to_string()),
+					version_id: Value("1234".to_string()),
+					delete_marker_version_id: Value("4321".to_string()),
+				},
+			],
+			errors: vec![
+				DeleteError {
+					code: Value("NotFound".to_string()),
+					key: Some(Value("c/plap".to_string())),
+					message: Value("Object c/plap not found".to_string()),
+					version_id: None,
+				},
+				DeleteError {
+					code: Value("Forbidden".to_string()),
+					key: Some(Value("d/plep".to_string())),
+					message: Value("Not authorized".to_string()),
+					version_id: Some(Value("789".to_string())),
+				},
+			],
+		};
+		assert_eq!(
+			to_xml_with_header(&delete_result)?,
+			"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\
+<DeleteResult xmlns=\"http://s3.amazonaws.com/doc/2006-03-01/\">\
+    <Deleted>\
+        <Key>a/plop</Key>\
+        <VersionId>qsdfjklm</VersionId>\
+        <DeleteMarkerVersionId>wxcvbn</DeleteMarkerVersionId>\
+    </Deleted>\
+    <Deleted>\
+        <Key>b/plip</Key>\
+        <VersionId>1234</VersionId>\
+        <DeleteMarkerVersionId>4321</DeleteMarkerVersionId>\
+    </Deleted>\
+    <Error>\
+        <Code>NotFound</Code>\
+        <Key>c/plap</Key>\
+        <Message>Object c/plap not found</Message>\
+    </Error>\
+    <Error>\
+        <Code>Forbidden</Code>\
+        <Key>d/plep</Key>\
+        <Message>Not authorized</Message>\
+        <VersionId>789</VersionId>\
+    </Error>\
+</DeleteResult>"
+		);
+		Ok(())
+	}
+
+	#[test]
+	fn copy_object_result() -> Result<(), ApiError> {
+		let copy_result = CopyObjectResult {
+			last_modified: Value(msec_to_rfc3339(0)),
+			etag: Value("9b2cf535f27731c974343645a3985328".to_string()),
+		};
+		assert_eq!(
+			to_xml_with_header(&copy_result)?,
+			"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\
+<CopyObjectResult>\
+    <LastModified>1970-01-01T00:00:00.000Z</LastModified>\
+    <ETag>9b2cf535f27731c974343645a3985328</ETag>\
+</CopyObjectResult>\
+			"
+		);
+		Ok(())
+	}
+
+	#[test]
+	fn initiate_multipart_upload_result() -> Result<(), ApiError> {
+		let result = InitiateMultipartUploadResult {
+			xmlns: (),
+			bucket: Value("mybucket".to_string()),
+			key: Value("a/plop".to_string()),
+			upload_id: Value("azerty".to_string()),
+		};
+		assert_eq!(
+			to_xml_with_header(&result)?,
+			"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\
+<InitiateMultipartUploadResult xmlns=\"http://s3.amazonaws.com/doc/2006-03-01/\">\
+	<Bucket>mybucket</Bucket>\
+	<Key>a/plop</Key>\
+	<UploadId>azerty</UploadId>\
+</InitiateMultipartUploadResult>"
+		);
+		Ok(())
+	}
+
+	#[test]
+	fn complete_multipart_upload_result() -> Result<(), ApiError> {
+		let result = CompleteMultipartUploadResult {
+			xmlns: (),
+			location: Some(Value("https://garage.tld/mybucket/a/plop".to_string())),
+			bucket: Value("mybucket".to_string()),
+			key: Value("a/plop".to_string()),
+			etag: Value("3858f62230ac3c915f300c664312c11f-9".to_string()),
+		};
+		assert_eq!(
+			to_xml_with_header(&result)?,
+			"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\
+<CompleteMultipartUploadResult xmlns=\"http://s3.amazonaws.com/doc/2006-03-01/\">\
+	<Location>https://garage.tld/mybucket/a/plop</Location>\
+	<Bucket>mybucket</Bucket>\
+	<Key>a/plop</Key>\
+	<ETag>3858f62230ac3c915f300c664312c11f-9</ETag>\
+</CompleteMultipartUploadResult>"
+		);
+		Ok(())
+	}
+
+	#[test]
+	fn list_objects_v1_1() -> Result<(), ApiError> {
+		let result = ListBucketResult {
+			xmlns: (),
+			name: Value("example-bucket".to_string()),
+			prefix: Value("".to_string()),
+			marker: Some(Value("".to_string())),
+			next_marker: None,
+			start_after: None,
+			continuation_token: None,
+			next_continuation_token: None,
+			key_count: None,
+			max_keys: IntValue(1000),
+			encoding_type: None,
+			delimiter: Some(Value("/".to_string())),
+			is_truncated: Value("false".to_string()),
+			contents: vec![ListBucketItem {
+				key: Value("sample.jpg".to_string()),
+				last_modified: Value(msec_to_rfc3339(0)),
+				etag: Value("bf1d737a4d46a19f3bced6905cc8b902".to_string()),
+				size: IntValue(142863),
+				storage_class: Value("STANDARD".to_string()),
+			}],
+			common_prefixes: vec![CommonPrefix {
+				prefix: Value("photos/".to_string()),
+			}],
+		};
+		assert_eq!(
+			to_xml_with_header(&result)?,
+			"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\
+<ListBucketResult xmlns=\"http://s3.amazonaws.com/doc/2006-03-01/\">\
+  <Name>example-bucket</Name>\
+  <Prefix></Prefix>\
+  <Marker></Marker>\
+  <MaxKeys>1000</MaxKeys>\
+  <Delimiter>/</Delimiter>\
+  <IsTruncated>false</IsTruncated>\
+  <Contents>\
+    <Key>sample.jpg</Key>\
+    <LastModified>1970-01-01T00:00:00.000Z</LastModified>\
+    <ETag>bf1d737a4d46a19f3bced6905cc8b902</ETag>\
+    <Size>142863</Size>\
+    <StorageClass>STANDARD</StorageClass>\
+  </Contents>\
+  <CommonPrefixes>\
+    <Prefix>photos/</Prefix>\
+  </CommonPrefixes>\
+</ListBucketResult>"
+		);
+		Ok(())
+	}
+
+	#[test]
+	fn list_objects_v1_2() -> Result<(), ApiError> {
+		let result = ListBucketResult {
+			xmlns: (),
+			name: Value("example-bucket".to_string()),
+			prefix: Value("photos/2006/".to_string()),
+			marker: Some(Value("".to_string())),
+			next_marker: None,
+			start_after: None,
+			continuation_token: None,
+			next_continuation_token: None,
+			key_count: None,
+			max_keys: IntValue(1000),
+			delimiter: Some(Value("/".to_string())),
+			encoding_type: None,
+			is_truncated: Value("false".to_string()),
+			contents: vec![],
+			common_prefixes: vec![
+				CommonPrefix {
+					prefix: Value("photos/2006/February/".to_string()),
+				},
+				CommonPrefix {
+					prefix: Value("photos/2006/January/".to_string()),
+				},
+			],
+		};
+		assert_eq!(
+			to_xml_with_header(&result)?,
+			"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\
+<ListBucketResult xmlns=\"http://s3.amazonaws.com/doc/2006-03-01/\">\
+  <Name>example-bucket</Name>\
+  <Prefix>photos/2006/</Prefix>\
+  <Marker></Marker>\
+  <MaxKeys>1000</MaxKeys>\
+  <Delimiter>/</Delimiter>\
+  <IsTruncated>false</IsTruncated>\
+  <CommonPrefixes>\
+    <Prefix>photos/2006/February/</Prefix>\
+  </CommonPrefixes>\
+  <CommonPrefixes>\
+    <Prefix>photos/2006/January/</Prefix>\
+  </CommonPrefixes>\
+</ListBucketResult>"
+		);
+		Ok(())
+	}
+
+	#[test]
+	fn list_objects_v2_1() -> Result<(), ApiError> {
+		let result = ListBucketResult {
+			xmlns: (),
+			name: Value("quotes".to_string()),
+			prefix: Value("E".to_string()),
+			marker: None,
+			next_marker: None,
+			start_after: Some(Value("ExampleGuide.pdf".to_string())),
+			continuation_token: None,
+			next_continuation_token: None,
+			key_count: None,
+			max_keys: IntValue(3),
+			delimiter: None,
+			encoding_type: None,
+			is_truncated: Value("false".to_string()),
+			contents: vec![ListBucketItem {
+				key: Value("ExampleObject.txt".to_string()),
+				last_modified: Value(msec_to_rfc3339(0)),
+				etag: Value("599bab3ed2c697f1d26842727561fd94".to_string()),
+				size: IntValue(857),
+				storage_class: Value("REDUCED_REDUNDANCY".to_string()),
+			}],
+			common_prefixes: vec![],
+		};
+		assert_eq!(
+			to_xml_with_header(&result)?,
+			"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\
+<ListBucketResult xmlns=\"http://s3.amazonaws.com/doc/2006-03-01/\">\
+  <Name>quotes</Name>\
+  <Prefix>E</Prefix>\
+  <StartAfter>ExampleGuide.pdf</StartAfter>\
+  <MaxKeys>3</MaxKeys>\
+  <IsTruncated>false</IsTruncated>\
+  <Contents>\
+    <Key>ExampleObject.txt</Key>\
+    <LastModified>1970-01-01T00:00:00.000Z</LastModified>\
+    <ETag>599bab3ed2c697f1d26842727561fd94</ETag>\
+    <Size>857</Size>\
+    <StorageClass>REDUCED_REDUNDANCY</StorageClass>\
+  </Contents>\
+</ListBucketResult>"
+		);
+		Ok(())
+	}
+
+	#[test]
+	fn list_objects_v2_2() -> Result<(), ApiError> {
+		let result = ListBucketResult {
+			xmlns: (),
+			name: Value("bucket".to_string()),
+			prefix: Value("".to_string()),
+			marker: None,
+			next_marker: None,
+			start_after: None,
+			continuation_token: Some(Value(
+				"1ueGcxLPRx1Tr/XYExHnhbYLgveDs2J/wm36Hy4vbOwM=".to_string(),
+			)),
+			next_continuation_token: Some(Value("qsdfjklm".to_string())),
+			key_count: Some(IntValue(112)),
+			max_keys: IntValue(1000),
+			delimiter: None,
+			encoding_type: None,
+			is_truncated: Value("false".to_string()),
+			contents: vec![ListBucketItem {
+				key: Value("happyfacex.jpg".to_string()),
+				last_modified: Value(msec_to_rfc3339(0)),
+				etag: Value("70ee1738b6b21e2c8a43f3a5ab0eee71".to_string()),
+				size: IntValue(1111),
+				storage_class: Value("STANDARD".to_string()),
+			}],
+			common_prefixes: vec![],
+		};
+		assert_eq!(
+			to_xml_with_header(&result)?,
+			"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\
+<ListBucketResult xmlns=\"http://s3.amazonaws.com/doc/2006-03-01/\">\
+  <Name>bucket</Name>\
+  <Prefix></Prefix>\
+  <ContinuationToken>1ueGcxLPRx1Tr/XYExHnhbYLgveDs2J/wm36Hy4vbOwM=</ContinuationToken>\
+  <NextContinuationToken>qsdfjklm</NextContinuationToken>\
+  <KeyCount>112</KeyCount>\
+  <MaxKeys>1000</MaxKeys>\
+  <IsTruncated>false</IsTruncated>\
+  <Contents>\
+    <Key>happyfacex.jpg</Key>\
+    <LastModified>1970-01-01T00:00:00.000Z</LastModified>\
+    <ETag>70ee1738b6b21e2c8a43f3a5ab0eee71</ETag>\
+    <Size>1111</Size>\
+    <StorageClass>STANDARD</StorageClass>\
+  </Contents>\
+</ListBucketResult>"
+		);
+		Ok(())
+	}
+}
diff --git a/src/util/time.rs b/src/util/time.rs
index dfedcb2..238db2c 100644
--- a/src/util/time.rs
+++ b/src/util/time.rs
@@ -16,5 +16,5 @@ pub fn msec_to_rfc3339(msecs: u64) -> String {
 	let secs = msecs as i64 / 1000;
 	let nanos = (msecs as i64 % 1000) as u32 * 1_000_000;
 	let timestamp = Utc.timestamp(secs, nanos);
-	timestamp.to_rfc3339_opts(SecondsFormat::Secs, true)
+	timestamp.to_rfc3339_opts(SecondsFormat::Millis, true)
 }