Support for PostObject (#222)

Add support for [PostObject](https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectPOST.html) - [x] routing PostObject properly - [x] parsing multipart body - [x] validating signature - [x] validating policy - [x] validating content length - [x] actually saving data Co-authored-by: trinity-1686a <trinity@deuxfleurs.fr> Co-authored-by: Trinity Pointard <trinity.pointard@gmail.com> Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/222 Reviewed-by: Alex <alex@adnab.me> Co-authored-by: trinity-1686a <trinity.pointard@gmail.com> Co-committed-by: trinity-1686a <trinity.pointard@gmail.com>
author: trinity-1686a <trinity.pointard@gmail.com> 2022-02-21 23:02:30 +0100
committer: Alex <alex@adnab.me> 2022-02-21 23:02:30 +0100
commit: f6f8b7f1ad865f629bdfd93ec1e28a526a5eab37 (patch)
tree: b80fef17e63b25c6ba73bb4463660f7356bcabd4 /src/api/s3_post_object.rs
parent: e312ba977e2c99d3d0b3734f500369c3cd697d0d (diff)
download: garage-f6f8b7f1ad865f629bdfd93ec1e28a526a5eab37.tar.gz
garage-f6f8b7f1ad865f629bdfd93ec1e28a526a5eab37.zip
1 files changed, 499 insertions, 0 deletions
diff --git a/src/api/s3_post_object.rs b/src/api/s3_post_object.rs
new file mode 100644
index 00000000..585e0304
--- /dev/null
+++ b/src/api/s3_post_object.rs
@@ -0,0 +1,499 @@
+use std::collections::HashMap;
+use std::convert::TryInto;
+use std::ops::RangeInclusive;
+use std::sync::Arc;
+use std::task::{Context, Poll};
+
+use bytes::Bytes;
+use chrono::{DateTime, Duration, Utc};
+use futures::{Stream, StreamExt};
+use hyper::header::{self, HeaderMap, HeaderName, HeaderValue};
+use hyper::{Body, Request, Response, StatusCode};
+use multer::{Constraints, Multipart, SizeLimit};
+use serde::Deserialize;
+
+use garage_model::garage::Garage;
+
+use crate::api_server::resolve_bucket;
+use crate::error::*;
+use crate::s3_put::{get_headers, save_stream};
+use crate::s3_xml;
+use crate::signature::payload::{parse_date, verify_v4};
+
+pub async fn handle_post_object(
+	garage: Arc<Garage>,
+	req: Request<Body>,
+	bucket: String,
+) -> Result<Response<Body>, Error> {
+	let boundary = req
+		.headers()
+		.get(header::CONTENT_TYPE)
+		.and_then(|ct| ct.to_str().ok())
+		.and_then(|ct| multer::parse_boundary(ct).ok())
+		.ok_or_bad_request("Counld not get multipart boundary")?;
+
+	// 16k seems plenty for a header. 5G is the max size of a single part, so it seems reasonable
+	// for a PostObject
+	let constraints = Constraints::new().size_limit(
+		SizeLimit::new()
+			.per_field(16 * 1024)
+			.for_field("file", 5 * 1024 * 1024 * 1024),
+	);
+
+	let (head, body) = req.into_parts();
+	let mut multipart = Multipart::with_constraints(body, boundary, constraints);
+
+	let mut params = HeaderMap::new();
+	let field = loop {
+		let field = if let Some(field) = multipart.next_field().await? {
+			field
+		} else {
+			return Err(Error::BadRequest(
+				"Request did not contain a file".to_owned(),
+			));
+		};
+		let name: HeaderName = if let Some(Ok(name)) = field.name().map(TryInto::try_into) {
+			name
+		} else {
+			continue;
+		};
+		if name == "file" {
+			break field;
+		}
+
+		if let Ok(content) = HeaderValue::from_str(&field.text().await?) {
+			match name.as_str() {
+				"tag" => (/* tag need to be reencoded, but we don't support them yet anyway */),
+				"acl" => {
+					if params.insert("x-amz-acl", content).is_some() {
+						return Err(Error::BadRequest(
+							"Field 'acl' provided more than one time".to_string(),
+						));
+					}
+				}
+				_ => {
+					if params.insert(&name, content).is_some() {
+						return Err(Error::BadRequest(format!(
+							"Field '{}' provided more than one time",
+							name
+						)));
+					}
+				}
+			}
+		}
+	};
+
+	// Current part is file. Do some checks before handling to PutObject code
+	let key = params
+		.get("key")
+		.ok_or_bad_request("No key was provided")?
+		.to_str()?;
+	let credential = params
+		.get("x-amz-credential")
+		.ok_or_else(|| {
+			Error::Forbidden("Garage does not support anonymous access yet".to_string())
+		})?
+		.to_str()?;
+	let policy = params
+		.get("policy")
+		.ok_or_bad_request("No policy was provided")?
+		.to_str()?;
+	let signature = params
+		.get("x-amz-signature")
+		.ok_or_bad_request("No signature was provided")?
+		.to_str()?;
+	let date = params
+		.get("x-amz-date")
+		.ok_or_bad_request("No date was provided")?
+		.to_str()?;
+
+	let key = if key.contains("${filename}") {
+		// if no filename is provided, don't replace. This matches the behavior of AWS.
+		if let Some(filename) = field.file_name() {
+			key.replace("${filename}", filename)
+		} else {
+			key.to_owned()
+		}
+	} else {
+		key.to_owned()
+	};
+
+	let date = parse_date(date)?;
+	let api_key = verify_v4(&garage, credential, &date, signature, policy.as_bytes()).await?;
+
+	let bucket_id = resolve_bucket(&garage, &bucket, &api_key).await?;
+
+	if !api_key.allow_write(&bucket_id) {
+		return Err(Error::Forbidden(
+			"Operation is not allowed for this key.".to_string(),
+		));
+	}
+
+	let decoded_policy = base64::decode(&policy)?;
+	let decoded_policy: Policy =
+		serde_json::from_slice(&decoded_policy).ok_or_bad_request("Invalid policy")?;
+
+	let expiration: DateTime<Utc> = DateTime::parse_from_rfc3339(&decoded_policy.expiration)
+		.ok_or_bad_request("Invalid expiration date")?
+		.into();
+	if Utc::now() - expiration > Duration::zero() {
+		return Err(Error::BadRequest(
+			"Expiration date is in the paste".to_string(),
+		));
+	}
+
+	let mut conditions = decoded_policy.into_conditions()?;
+
+	for (param_key, value) in params.iter() {
+		let mut param_key = param_key.to_string();
+		param_key.make_ascii_lowercase();
+		match param_key.as_str() {
+			"policy" | "x-amz-signature" => (), // this is always accepted, as it's required to validate other fields
+			"content-type" => {
+				let conds = conditions.params.remove("content-type").ok_or_else(|| {
+					Error::BadRequest(format!("Key '{}' is not allowed in policy", param_key))
+				})?;
+				for cond in conds {
+					let ok = match cond {
+						Operation::Equal(s) => s.as_str() == value,
+						Operation::StartsWith(s) => {
+							value.to_str()?.split(',').all(|v| v.starts_with(&s))
+						}
+					};
+					if !ok {
+						return Err(Error::BadRequest(format!(
+							"Key '{}' has value not allowed in policy",
+							param_key
+						)));
+					}
+				}
+			}
+			"key" => {
+				let conds = conditions.params.remove("key").ok_or_else(|| {
+					Error::BadRequest(format!("Key '{}' is not allowed in policy", param_key))
+				})?;
+				for cond in conds {
+					let ok = match cond {
+						Operation::Equal(s) => s == key,
+						Operation::StartsWith(s) => key.starts_with(&s),
+					};
+					if !ok {
+						return Err(Error::BadRequest(format!(
+							"Key '{}' has value not allowed in policy",
+							param_key
+						)));
+					}
+				}
+			}
+			_ => {
+				if param_key.starts_with("x-ignore-") {
+					// if a x-ignore is provided in policy, it's not removed here, so it will be
+					// rejected as provided in policy but not in the request. As odd as it is, it's
+					// how aws seems to behave.
+					continue;
+				}
+				let conds = conditions.params.remove(&param_key).ok_or_else(|| {
+					Error::BadRequest(format!("Key '{}' is not allowed in policy", param_key))
+				})?;
+				for cond in conds {
+					let ok = match cond {
+						Operation::Equal(s) => s.as_str() == value,
+						Operation::StartsWith(s) => value.to_str()?.starts_with(s.as_str()),
+					};
+					if !ok {
+						return Err(Error::BadRequest(format!(
+							"Key '{}' has value not allowed in policy",
+							param_key
+						)));
+					}
+				}
+			}
+		}
+	}
+
+	if let Some((param_key, _)) = conditions.params.iter().next() {
+		return Err(Error::BadRequest(format!(
+			"Key '{}' is required in policy, but no value was provided",
+			param_key
+		)));
+	}
+
+	let headers = get_headers(&params)?;
+
+	let stream = field.map(|r| r.map_err(Into::into));
+	let (_, md5) = save_stream(
+		garage,
+		headers,
+		StreamLimiter::new(stream, conditions.content_length),
+		bucket_id,
+		&key,
+		None,
+		None,
+	)
+	.await?;
+
+	let etag = format!("\"{}\"", md5);
+
+	let resp = if let Some(mut target) = params
+		.get("success_action_redirect")
+		.and_then(|h| h.to_str().ok())
+		.and_then(|u| url::Url::parse(u).ok())
+		.filter(|u| u.scheme() == "https" || u.scheme() == "http")
+	{
+		target
+			.query_pairs_mut()
+			.append_pair("bucket", &bucket)
+			.append_pair("key", &key)
+			.append_pair("etag", &etag);
+		let target = target.to_string();
+		Response::builder()
+			.status(StatusCode::SEE_OTHER)
+			.header(header::LOCATION, target.clone())
+			.header(header::ETAG, etag)
+			.body(target.into())?
+	} else {
+		let path = head
+			.uri
+			.into_parts()
+			.path_and_query
+			.map(|paq| paq.path().to_string())
+			.unwrap_or_else(|| "/".to_string());
+		let authority = head
+			.headers
+			.get(header::HOST)
+			.and_then(|h| h.to_str().ok())
+			.unwrap_or_default();
+		let proto = if !authority.is_empty() {
+			"https://"
+		} else {
+			""
+		};
+
+		let url_key: String = form_urlencoded::byte_serialize(key.as_bytes())
+			.flat_map(str::chars)
+			.collect();
+		let location = format!("{}{}{}{}", proto, authority, path, url_key);
+
+		let action = params
+			.get("success_action_status")
+			.and_then(|h| h.to_str().ok())
+			.unwrap_or("204");
+		let builder = Response::builder()
+			.header(header::LOCATION, location.clone())
+			.header(header::ETAG, etag.clone());
+		match action {
+			"200" => builder.status(StatusCode::OK).body(Body::empty())?,
+			"201" => {
+				let xml = s3_xml::PostObject {
+					xmlns: (),
+					location: s3_xml::Value(location),
+					bucket: s3_xml::Value(bucket),
+					key: s3_xml::Value(key),
+					etag: s3_xml::Value(etag),
+				};
+				let body = s3_xml::to_xml_with_header(&xml)?;
+				builder
+					.status(StatusCode::CREATED)
+					.body(Body::from(body.into_bytes()))?
+			}
+			_ => builder.status(StatusCode::NO_CONTENT).body(Body::empty())?,
+		}
+	};
+
+	Ok(resp)
+}
+
+#[derive(Deserialize)]
+struct Policy {
+	expiration: String,
+	conditions: Vec<PolicyCondition>,
+}
+
+impl Policy {
+	fn into_conditions(self) -> Result<Conditions, Error> {
+		let mut params = HashMap::<_, Vec<_>>::new();
+
+		let mut length = (0, u64::MAX);
+		for condition in self.conditions {
+			match condition {
+				PolicyCondition::Equal(map) => {
+					if map.len() != 1 {
+						return Err(Error::BadRequest("Invalid policy item".to_owned()));
+					}
+					let (mut k, v) = map.into_iter().next().expect("size was verified");
+					k.make_ascii_lowercase();
+					params.entry(k).or_default().push(Operation::Equal(v));
+				}
+				PolicyCondition::OtherOp([cond, mut key, value]) => {
+					if key.remove(0) != '$' {
+						return Err(Error::BadRequest("Invalid policy item".to_owned()));
+					}
+					key.make_ascii_lowercase();
+					match cond.as_str() {
+						"eq" => {
+							params.entry(key).or_default().push(Operation::Equal(value));
+						}
+						"starts-with" => {
+							params
+								.entry(key)
+								.or_default()
+								.push(Operation::StartsWith(value));
+						}
+						_ => return Err(Error::BadRequest("Invalid policy item".to_owned())),
+					}
+				}
+				PolicyCondition::SizeRange(key, min, max) => {
+					if key == "content-length-range" {
+						length.0 = length.0.max(min);
+						length.1 = length.1.min(max);
+					} else {
+						return Err(Error::BadRequest("Invalid policy item".to_owned()));
+					}
+				}
+			}
+		}
+		Ok(Conditions {
+			params,
+			content_length: RangeInclusive::new(length.0, length.1),
+		})
+	}
+}
+
+/// A single condition from a policy
+#[derive(Debug, Deserialize)]
+#[serde(untagged)]
+enum PolicyCondition {
+	// will contain a single key-value pair
+	Equal(HashMap<String, String>),
+	OtherOp([String; 3]),
+	SizeRange(String, u64, u64),
+}
+
+#[derive(Debug)]
+struct Conditions {
+	params: HashMap<String, Vec<Operation>>,
+	content_length: RangeInclusive<u64>,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+enum Operation {
+	Equal(String),
+	StartsWith(String),
+}
+
+struct StreamLimiter<T> {
+	inner: T,
+	length: RangeInclusive<u64>,
+	read: u64,
+}
+
+impl<T> StreamLimiter<T> {
+	fn new(stream: T, length: RangeInclusive<u64>) -> Self {
+		StreamLimiter {
+			inner: stream,
+			length,
+			read: 0,
+		}
+	}
+}
+
+impl<T> Stream for StreamLimiter<T>
+where
+	T: Stream<Item = Result<Bytes, Error>> + Unpin,
+{
+	type Item = Result<Bytes, Error>;
+	fn poll_next(
+		mut self: std::pin::Pin<&mut Self>,
+		ctx: &mut Context<'_>,
+	) -> Poll<Option<Self::Item>> {
+		let res = std::pin::Pin::new(&mut self.inner).poll_next(ctx);
+		match &res {
+			Poll::Ready(Some(Ok(bytes))) => {
+				self.read += bytes.len() as u64;
+				// optimization to fail early when we know before the end it's too long
+				if self.length.end() < &self.read {
+					return Poll::Ready(Some(Err(Error::BadRequest(
+						"File size does not match policy".to_owned(),
+					))));
+				}
+			}
+			Poll::Ready(None) => {
+				if !self.length.contains(&self.read) {
+					return Poll::Ready(Some(Err(Error::BadRequest(
+						"File size does not match policy".to_owned(),
+					))));
+				}
+			}
+			_ => {}
+		}
+		res
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	#[test]
+	fn test_policy_1() {
+		let policy_json = br#"
+{ "expiration": "2007-12-01T12:00:00.000Z",
+  "conditions": [
+    {"acl": "public-read" },
+    {"bucket": "johnsmith" },
+    ["starts-with", "$key", "user/eric/"]
+  ]
+}
+		"#;
+		let policy_2: Policy = serde_json::from_slice(&policy_json[..]).unwrap();
+		let mut conditions = policy_2.into_conditions().unwrap();
+
+		assert_eq!(
+			conditions.params.remove(&"acl".to_string()),
+			Some(vec![Operation::Equal("public-read".into())])
+		);
+		assert_eq!(
+			conditions.params.remove(&"bucket".to_string()),
+			Some(vec![Operation::Equal("johnsmith".into())])
+		);
+		assert_eq!(
+			conditions.params.remove(&"key".to_string()),
+			Some(vec![Operation::StartsWith("user/eric/".into())])
+		);
+		assert!(conditions.params.is_empty());
+		assert_eq!(conditions.content_length, 0..=u64::MAX);
+	}
+
+	#[test]
+	fn test_policy_2() {
+		let policy_json = br#"
+{ "expiration": "2007-12-01T12:00:00.000Z",
+  "conditions": [
+	[ "eq", "$acl", "public-read" ],
+	["starts-with", "$Content-Type", "image/"],
+	["starts-with", "$success_action_redirect", ""],
+	["content-length-range", 1048576, 10485760]
+  ]
+}
+		"#;
+		let policy_2: Policy = serde_json::from_slice(&policy_json[..]).unwrap();
+		let mut conditions = policy_2.into_conditions().unwrap();
+
+		assert_eq!(
+			conditions.params.remove(&"acl".to_string()),
+			Some(vec![Operation::Equal("public-read".into())])
+		);
+		assert_eq!(
+			conditions.params.remove("content-type").unwrap(),
+			vec![Operation::StartsWith("image/".into())]
+		);
+		assert_eq!(
+			conditions
+				.params
+				.remove(&"success_action_redirect".to_string()),
+			Some(vec![Operation::StartsWith("".into())])
+		);
+		assert!(conditions.params.is_empty());
+		assert_eq!(conditions.content_length, 1048576..=10485760);
+	}
+}
author	trinity-1686a <trinity.pointard@gmail.com>	2022-02-21 23:02:30 +0100
committer	Alex <alex@adnab.me>	2022-02-21 23:02:30 +0100
commit	f6f8b7f1ad865f629bdfd93ec1e28a526a5eab37 (patch)
tree	b80fef17e63b25c6ba73bb4463660f7356bcabd4 /src/api/s3_post_object.rs
parent	e312ba977e2c99d3d0b3734f500369c3cd697d0d (diff)
download	garage-f6f8b7f1ad865f629bdfd93ec1e28a526a5eab37.tar.gz garage-f6f8b7f1ad865f629bdfd93ec1e28a526a5eab37.zip