forked from Deuxfleurs/garage
359 lines
11 KiB
Rust
359 lines
11 KiB
Rust
use std::collections::HashMap;
|
|
|
|
use chrono::{DateTime, Duration, NaiveDateTime, Utc};
|
|
use hmac::Mac;
|
|
use hyper::{Body, Method, Request};
|
|
use sha2::{Digest, Sha256};
|
|
|
|
use garage_table::*;
|
|
use garage_util::data::Hash;
|
|
|
|
use garage_model::garage::Garage;
|
|
use garage_model::key_table::*;
|
|
|
|
use super::LONG_DATETIME;
|
|
use super::{compute_scope, signing_hmac};
|
|
|
|
use crate::encoding::uri_encode;
|
|
use crate::signature::error::*;
|
|
|
|
pub async fn check_payload_signature(
|
|
garage: &Garage,
|
|
service: &'static str,
|
|
request: &Request<Body>,
|
|
) -> Result<(Option<Key>, Option<Hash>), Error> {
|
|
let mut headers = HashMap::new();
|
|
for (key, val) in request.headers() {
|
|
headers.insert(key.to_string(), val.to_str()?.to_string());
|
|
}
|
|
if let Some(query) = request.uri().query() {
|
|
let query_pairs = url::form_urlencoded::parse(query.as_bytes());
|
|
for (key, val) in query_pairs {
|
|
headers.insert(key.to_lowercase(), val.to_string());
|
|
}
|
|
}
|
|
|
|
let authorization = if let Some(authorization) = headers.get("authorization") {
|
|
parse_authorization(authorization, &headers)?
|
|
} else if let Some(algorithm) = headers.get("x-amz-algorithm") {
|
|
parse_query_authorization(algorithm, &headers)?
|
|
} else {
|
|
let content_sha256 = headers.get("x-amz-content-sha256");
|
|
if let Some(content_sha256) = content_sha256.filter(|c| "UNSIGNED-PAYLOAD" != c.as_str()) {
|
|
let sha256 = hex::decode(content_sha256)
|
|
.ok()
|
|
.and_then(|bytes| Hash::try_from(&bytes))
|
|
.ok_or_bad_request("Invalid content sha256 hash")?;
|
|
return Ok((None, Some(sha256)));
|
|
} else {
|
|
return Ok((None, None));
|
|
}
|
|
};
|
|
|
|
let canonical_request = canonical_request(
|
|
service,
|
|
request.method(),
|
|
request.uri(),
|
|
&headers,
|
|
&authorization.signed_headers,
|
|
&authorization.content_sha256,
|
|
);
|
|
let (_, scope) = parse_credential(&authorization.credential)?;
|
|
let string_to_sign = string_to_sign(&authorization.date, &scope, &canonical_request);
|
|
|
|
trace!("canonical request:\n{}", canonical_request);
|
|
trace!("string to sign:\n{}", string_to_sign);
|
|
|
|
let key = verify_v4(
|
|
garage,
|
|
service,
|
|
&authorization.credential,
|
|
&authorization.date,
|
|
&authorization.signature,
|
|
string_to_sign.as_bytes(),
|
|
)
|
|
.await?;
|
|
|
|
let content_sha256 = if authorization.content_sha256 == "UNSIGNED-PAYLOAD" {
|
|
None
|
|
} else if authorization.content_sha256 == "STREAMING-AWS4-HMAC-SHA256-PAYLOAD" {
|
|
let bytes = hex::decode(authorization.signature).ok_or_bad_request("Invalid signature")?;
|
|
Some(Hash::try_from(&bytes).ok_or_bad_request("Invalid signature")?)
|
|
} else {
|
|
let bytes = hex::decode(authorization.content_sha256)
|
|
.ok_or_bad_request("Invalid content sha256 hash")?;
|
|
Some(Hash::try_from(&bytes).ok_or_bad_request("Invalid content sha256 hash")?)
|
|
};
|
|
|
|
Ok((Some(key), content_sha256))
|
|
}
|
|
|
|
struct Authorization {
|
|
credential: String,
|
|
signed_headers: String,
|
|
signature: String,
|
|
content_sha256: String,
|
|
date: DateTime<Utc>,
|
|
}
|
|
|
|
fn parse_authorization(
|
|
authorization: &str,
|
|
headers: &HashMap<String, String>,
|
|
) -> Result<Authorization, Error> {
|
|
let first_space = authorization
|
|
.find(' ')
|
|
.ok_or_bad_request("Authorization field to short")?;
|
|
let (auth_kind, rest) = authorization.split_at(first_space);
|
|
|
|
if auth_kind != "AWS4-HMAC-SHA256" {
|
|
return Err(Error::bad_request("Unsupported authorization method"));
|
|
}
|
|
|
|
let mut auth_params = HashMap::new();
|
|
for auth_part in rest.split(',') {
|
|
let auth_part = auth_part.trim();
|
|
let eq = auth_part
|
|
.find('=')
|
|
.ok_or_bad_request("Field without value in authorization header")?;
|
|
let (key, value) = auth_part.split_at(eq);
|
|
auth_params.insert(key.to_string(), value.trim_start_matches('=').to_string());
|
|
}
|
|
|
|
let cred = auth_params
|
|
.get("Credential")
|
|
.ok_or_bad_request("Could not find Credential in Authorization field")?;
|
|
|
|
let content_sha256 = headers
|
|
.get("x-amz-content-sha256")
|
|
.ok_or_bad_request("Missing X-Amz-Content-Sha256 field")?;
|
|
|
|
let date = headers
|
|
.get("x-amz-date")
|
|
.ok_or_bad_request("Missing X-Amz-Date field")
|
|
.map_err(Error::from)
|
|
.and_then(|d| parse_date(d))?;
|
|
|
|
if Utc::now() - date > Duration::hours(24) {
|
|
return Err(Error::bad_request("Date is too old".to_string()));
|
|
}
|
|
|
|
let auth = Authorization {
|
|
credential: cred.to_string(),
|
|
signed_headers: auth_params
|
|
.get("SignedHeaders")
|
|
.ok_or_bad_request("Could not find SignedHeaders in Authorization field")?
|
|
.to_string(),
|
|
signature: auth_params
|
|
.get("Signature")
|
|
.ok_or_bad_request("Could not find Signature in Authorization field")?
|
|
.to_string(),
|
|
content_sha256: content_sha256.to_string(),
|
|
date,
|
|
};
|
|
Ok(auth)
|
|
}
|
|
|
|
fn parse_query_authorization(
|
|
algorithm: &str,
|
|
headers: &HashMap<String, String>,
|
|
) -> Result<Authorization, Error> {
|
|
if algorithm != "AWS4-HMAC-SHA256" {
|
|
return Err(Error::bad_request(
|
|
"Unsupported authorization method".to_string(),
|
|
));
|
|
}
|
|
|
|
let cred = headers
|
|
.get("x-amz-credential")
|
|
.ok_or_bad_request("X-Amz-Credential not found in query parameters")?;
|
|
let signed_headers = headers
|
|
.get("x-amz-signedheaders")
|
|
.ok_or_bad_request("X-Amz-SignedHeaders not found in query parameters")?;
|
|
let signature = headers
|
|
.get("x-amz-signature")
|
|
.ok_or_bad_request("X-Amz-Signature not found in query parameters")?;
|
|
let content_sha256 = headers
|
|
.get("x-amz-content-sha256")
|
|
.map(|x| x.as_str())
|
|
.unwrap_or("UNSIGNED-PAYLOAD");
|
|
|
|
let duration = headers
|
|
.get("x-amz-expires")
|
|
.ok_or_bad_request("X-Amz-Expires not found in query parameters")?
|
|
.parse()
|
|
.map_err(|_| Error::bad_request("X-Amz-Expires is not a number".to_string()))?;
|
|
|
|
if duration > 7 * 24 * 3600 {
|
|
return Err(Error::bad_request(
|
|
"X-Amz-Expires may not exceed a week".to_string(),
|
|
));
|
|
}
|
|
|
|
let date = headers
|
|
.get("x-amz-date")
|
|
.ok_or_bad_request("Missing X-Amz-Date field")
|
|
.map_err(Error::from)
|
|
.and_then(|d| parse_date(d))?;
|
|
|
|
if Utc::now() - date > Duration::seconds(duration) {
|
|
return Err(Error::bad_request("Date is too old".to_string()));
|
|
}
|
|
|
|
Ok(Authorization {
|
|
credential: cred.to_string(),
|
|
signed_headers: signed_headers.to_string(),
|
|
signature: signature.to_string(),
|
|
content_sha256: content_sha256.to_string(),
|
|
date,
|
|
})
|
|
}
|
|
|
|
fn parse_credential(cred: &str) -> Result<(String, String), Error> {
|
|
let first_slash = cred
|
|
.find('/')
|
|
.ok_or_bad_request("Credentials does not contain / in authorization field")?;
|
|
let (key_id, scope) = cred.split_at(first_slash);
|
|
Ok((
|
|
key_id.to_string(),
|
|
scope.trim_start_matches('/').to_string(),
|
|
))
|
|
}
|
|
|
|
pub fn string_to_sign(datetime: &DateTime<Utc>, scope_string: &str, canonical_req: &str) -> String {
|
|
let mut hasher = Sha256::default();
|
|
hasher.update(canonical_req.as_bytes());
|
|
[
|
|
"AWS4-HMAC-SHA256",
|
|
&datetime.format(LONG_DATETIME).to_string(),
|
|
scope_string,
|
|
&hex::encode(hasher.finalize().as_slice()),
|
|
]
|
|
.join("\n")
|
|
}
|
|
|
|
pub fn canonical_request(
|
|
service: &'static str,
|
|
method: &Method,
|
|
uri: &hyper::Uri,
|
|
headers: &HashMap<String, String>,
|
|
signed_headers: &str,
|
|
content_sha256: &str,
|
|
) -> String {
|
|
// There seems to be evidence that in AWSv4 signatures, the path component is url-encoded
|
|
// a second time when building the canonical request, as specified in this documentation page:
|
|
// -> https://docs.aws.amazon.com/rolesanywhere/latest/userguide/authentication-sign-process.html
|
|
// However this documentation page is for a specific service ("roles anywhere"), and
|
|
// in the S3 service we know for a fact that there is no double-urlencoding, because all of
|
|
// the tests we made with external software work without it.
|
|
//
|
|
// The theory is that double-urlencoding occurs for all services except S3,
|
|
// which is what is implemented in rusoto_signature:
|
|
// -> https://docs.rs/rusoto_signature/latest/src/rusoto_signature/signature.rs.html#464
|
|
//
|
|
// Digging into the code of the official AWS Rust SDK, we learn that double-URI-encoding can
|
|
// be set or unset on a per-request basis (the signature crates, aws-sigv4 and aws-sig-auth,
|
|
// are agnostic to this). Grepping the codebase confirms that S3 is the only API for which
|
|
// double_uri_encode is set to false, meaning it is true (its default value) for all other
|
|
// AWS services. We will therefore implement this behavior in Garage as well.
|
|
//
|
|
// Note that this documentation page, which is touted as the "authoritative reference" on
|
|
// AWSv4 signatures, makes no mention of either single- or double-urlencoding:
|
|
// -> https://docs.aws.amazon.com/IAM/latest/UserGuide/create-signed-request.html
|
|
// This page of the S3 documentation does also not mention anything specific:
|
|
// -> https://docs.aws.amazon.com/AmazonS3/latest/API/sig-v4-header-based-auth.html
|
|
//
|
|
// Note that there is also the issue of path normalization, which I hope is unrelated to the
|
|
// one of URI-encoding. At least in aws-sigv4 both parameters can be set independently,
|
|
// and rusoto_signature does not seem to do any effective path normalization, even though
|
|
// it mentions it in the comments (same link to the souce code as above).
|
|
// We make the explicit choice of NOT normalizing paths in the K2V API because doing so
|
|
// would make non-normalized paths invalid K2V partition keys, and we don't want that.
|
|
let path: std::borrow::Cow<str> = if service != "s3" {
|
|
uri_encode(uri.path(), false).into()
|
|
} else {
|
|
uri.path().into()
|
|
};
|
|
[
|
|
method.as_str(),
|
|
&path,
|
|
&canonical_query_string(uri),
|
|
&canonical_header_string(headers, signed_headers),
|
|
"",
|
|
signed_headers,
|
|
content_sha256,
|
|
]
|
|
.join("\n")
|
|
}
|
|
|
|
fn canonical_header_string(headers: &HashMap<String, String>, signed_headers: &str) -> String {
|
|
let signed_headers_vec = signed_headers.split(';').collect::<Vec<_>>();
|
|
let mut items = headers
|
|
.iter()
|
|
.filter(|(key, _)| signed_headers_vec.contains(&key.as_str()))
|
|
.collect::<Vec<_>>();
|
|
items.sort_by(|(k1, _), (k2, _)| k1.cmp(k2));
|
|
items
|
|
.iter()
|
|
.map(|(key, value)| key.to_lowercase() + ":" + value.trim())
|
|
.collect::<Vec<_>>()
|
|
.join("\n")
|
|
}
|
|
|
|
fn canonical_query_string(uri: &hyper::Uri) -> String {
|
|
if let Some(query) = uri.query() {
|
|
let query_pairs = url::form_urlencoded::parse(query.as_bytes());
|
|
let mut items = query_pairs
|
|
.filter(|(key, _)| key != "X-Amz-Signature")
|
|
.map(|(key, value)| uri_encode(&key, true) + "=" + &uri_encode(&value, true))
|
|
.collect::<Vec<_>>();
|
|
items.sort();
|
|
items.join("&")
|
|
} else {
|
|
"".to_string()
|
|
}
|
|
}
|
|
|
|
pub fn parse_date(date: &str) -> Result<DateTime<Utc>, Error> {
|
|
let date: NaiveDateTime =
|
|
NaiveDateTime::parse_from_str(date, LONG_DATETIME).ok_or_bad_request("Invalid date")?;
|
|
Ok(DateTime::from_utc(date, Utc))
|
|
}
|
|
|
|
pub async fn verify_v4(
|
|
garage: &Garage,
|
|
service: &str,
|
|
credential: &str,
|
|
date: &DateTime<Utc>,
|
|
signature: &str,
|
|
payload: &[u8],
|
|
) -> Result<Key, Error> {
|
|
let (key_id, scope) = parse_credential(credential)?;
|
|
|
|
let scope_expected = compute_scope(date, &garage.config.s3_api.s3_region, service);
|
|
if scope != scope_expected {
|
|
return Err(Error::AuthorizationHeaderMalformed(scope.to_string()));
|
|
}
|
|
|
|
let key = garage
|
|
.key_table
|
|
.get(&EmptyKey, &key_id)
|
|
.await?
|
|
.filter(|k| !k.state.is_deleted())
|
|
.ok_or_else(|| Error::forbidden(format!("No such key: {}", &key_id)))?;
|
|
let key_p = key.params().unwrap();
|
|
|
|
let mut hmac = signing_hmac(
|
|
date,
|
|
&key_p.secret_key,
|
|
&garage.config.s3_api.s3_region,
|
|
service,
|
|
)
|
|
.ok_or_internal_error("Unable to build signing HMAC")?;
|
|
hmac.update(payload);
|
|
let our_signature = hex::encode(hmac.finalize().into_bytes());
|
|
if signature != our_signature {
|
|
return Err(Error::forbidden("Invalid signature".to_string()));
|
|
}
|
|
|
|
Ok(key)
|
|
}
|