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authorAlex Auvolat <alex@adnab.me>2024-02-27 17:56:57 +0100
committerAlex Auvolat <alex@adnab.me>2024-02-27 17:56:57 +0100
commit7271e69fd0dd98fca3b3ca2e499fb861594b066a (patch)
tree4db8e716896223149a9b9b5d505cc0e473ad5f8b /src/api/signature
parent911a83ea7d06143c5a9621f88020ab6c0850ba54 (diff)
downloadgarage-7271e69fd0dd98fca3b3ca2e499fb861594b066a.tar.gz
garage-7271e69fd0dd98fca3b3ca2e499fb861594b066a.zip
[fix-presigned] WIP: try to split presigned/normal signature verification
Diffstat (limited to 'src/api/signature')
-rw-r--r--src/api/signature/payload.rs564
1 files changed, 352 insertions, 212 deletions
diff --git a/src/api/signature/payload.rs b/src/api/signature/payload.rs
index 423aad93..e2334ce7 100644
--- a/src/api/signature/payload.rs
+++ b/src/api/signature/payload.rs
@@ -1,7 +1,9 @@
use std::collections::HashMap;
+use std::convert::{TryFrom, TryInto};
use chrono::{DateTime, Duration, NaiveDateTime, TimeZone, Utc};
use hmac::Mac;
+use hyper::header::{HeaderMap, HeaderName, HeaderValue, AUTHORIZATION, CONTENT_TYPE, HOST};
use hyper::{body::Incoming as IncomingBody, Method, Request};
use sha2::{Digest, Sha256};
@@ -17,64 +19,82 @@ use super::{compute_scope, signing_hmac};
use crate::encoding::uri_encode;
use crate::signature::error::*;
+pub const X_AMZ_ALGORITHM: HeaderName = HeaderName::from_static("x-amz-algorithm");
+pub const X_AMZ_CREDENTIAL: HeaderName = HeaderName::from_static("x-amz-credential");
+pub const X_AMZ_DATE: HeaderName = HeaderName::from_static("x-amz-date");
+pub const X_AMZ_EXPIRES: HeaderName = HeaderName::from_static("x-amz-expires");
+pub const X_AMZ_SIGNEDHEADERS: HeaderName = HeaderName::from_static("x-amz-signedheaders");
+pub const X_AMZ_SIGNATURE: HeaderName = HeaderName::from_static("x-amz-signature");
+pub const X_AMZ_CONTENT_SH256: HeaderName = HeaderName::from_static("x-amz-content-sha256");
+
+pub const AWS4_HMAC_SHA256: &str = "AWS4-HMAC-SHA256";
+pub const UNSIGNED_PAYLOAD: &str = "UNSIGNED-PAYLOAD";
+
pub async fn check_payload_signature(
garage: &Garage,
service: &'static str,
request: &Request<IncomingBody>,
) -> 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 query = parse_query_map(request.uri())?;
- 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)?
+ let res = if query.contains_key(X_AMZ_ALGORITHM) {
+ check_presigned_signature(garage, service, request, query).await
} 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));
- }
+ check_standard_signature(garage, service, request, query).await
};
+ if let Err(e) = &res {
+ error!("ERROR IN SIGNATURE\n{:?}\n{}", request, e);
+ }
+
+ res
+}
+
+async fn check_standard_signature(
+ garage: &Garage,
+ service: &'static str,
+ request: &Request<IncomingBody>,
+ query: HeaderMap,
+) -> Result<(Option<Key>, Option<Hash>), Error> {
+ let authorization = Authorization::parse(request.headers())?;
+
+ // Verify that all necessary request headers are signed
+ let signed_headers = split_signed_headers(&authorization)?;
+ for (name, _) in request.headers().iter() {
+ if name.as_str().starts_with("x-amz-") || name == CONTENT_TYPE {
+ if !signed_headers.contains(name) {
+ return Err(Error::bad_request(format!(
+ "Header `{}` should be signed",
+ name
+ )));
+ }
+ }
+ }
+ if !signed_headers.contains(&HOST) {
+ return Err(Error::bad_request("Header `Host` should be signed"));
+ }
+
let canonical_request = canonical_request(
service,
request.method(),
- request.uri(),
- &headers,
- &authorization.signed_headers,
+ request.uri().path(),
+ &query,
+ request.headers(),
+ signed_headers,
&authorization.content_sha256,
+ )?;
+ let string_to_sign = string_to_sign(
+ &authorization.date,
+ &authorization.scope,
+ &canonical_request,
);
- 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 key = verify_v4(garage, service, &authorization, string_to_sign.as_bytes()).await?;
- let content_sha256 = if authorization.content_sha256 == "UNSIGNED-PAYLOAD" {
+ 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")?;
@@ -88,142 +108,92 @@ pub async fn check_payload_signature(
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"));
+async fn check_presigned_signature(
+ garage: &Garage,
+ service: &'static str,
+ request: &Request<IncomingBody>,
+ mut query: HeaderMap,
+) -> Result<(Option<Key>, Option<Hash>), Error> {
+ let algorithm = query.get(X_AMZ_ALGORITHM).unwrap().to_str()?;
+ let authorization = Authorization::parse_presigned(algorithm, &query)?;
+
+ // Check that all mandatory signed headers are included
+ let signed_headers = split_signed_headers(&authorization)?;
+ for (name, _) in request.headers().iter() {
+ if name.as_str().starts_with("x-amz-") {
+ if !signed_headers.contains(name) {
+ return Err(Error::bad_request(format!(
+ "Header `{}` should be signed",
+ name
+ )));
+ }
+ }
}
-
- 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());
+ if !signed_headers.contains(&HOST) {
+ return Err(Error::bad_request("Header `Host` should be signed"));
}
- 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")?;
+ query.remove(X_AMZ_SIGNATURE);
+ let canonical_request = canonical_request(
+ service,
+ request.method(),
+ request.uri().path(),
+ &query,
+ request.headers(),
+ signed_headers,
+ &authorization.content_sha256,
+ )?;
+ let string_to_sign = string_to_sign(
+ &authorization.date,
+ &authorization.scope,
+ &canonical_request,
+ );
- 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))?;
+ trace!("canonical request:\n{}", canonical_request);
+ trace!("string to sign:\n{}", string_to_sign);
- if Utc::now() - date > Duration::hours(24) {
- return Err(Error::bad_request("Date is too old".to_string()));
- }
+ let key = verify_v4(garage, service, &authorization, string_to_sign.as_bytes()).await?;
- 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)
+ Ok((Some(key), None))
}
-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()));
+pub fn parse_query_map(uri: &http::uri::Uri) -> Result<HeaderMap, Error> {
+ let mut query = HeaderMap::new();
+ if let Some(query_str) = uri.query() {
+ let query_pairs = url::form_urlencoded::parse(query_str.as_bytes());
+ for (key, val) in query_pairs {
+ let name: HeaderName = key
+ .to_lowercase()
+ .try_into()
+ .ok_or_bad_request("invalid query parameter name")?;
+ let value = HeaderValue::from_bytes(val.as_bytes())
+ .ok_or_bad_request("invalid query parameter value")?;
+ if query.insert(name.clone(), value).is_some() {
+ return Err(Error::bad_request(format!(
+ "duplicate query parameter: `{}`",
+ name
+ )));
+ }
+ }
}
-
- Ok(Authorization {
- credential: cred.to_string(),
- signed_headers: signed_headers.to_string(),
- signature: signature.to_string(),
- content_sha256: content_sha256.to_string(),
- date,
- })
+ Ok(query)
}
-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(),
- ))
+fn split_signed_headers(authorization: &Authorization) -> Result<Vec<HeaderName>, Error> {
+ let signed_headers = authorization
+ .signed_headers
+ .split(';')
+ .map(HeaderName::try_from)
+ .collect::<Result<Vec<HeaderName>, _>>()
+ .ok_or_bad_request("invalid header name")?;
+ Ok(signed_headers)
}
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",
+ AWS4_HMAC_SHA256,
&datetime.format(LONG_DATETIME).to_string(),
scope_string,
&hex::encode(hasher.finalize().as_slice()),
@@ -234,11 +204,12 @@ pub fn string_to_sign(datetime: &DateTime<Utc>, scope_string: &str, canonical_re
pub fn canonical_request(
service: &'static str,
method: &Method,
- uri: &hyper::Uri,
- headers: &HashMap<String, String>,
- signed_headers: &str,
+ canonical_uri: &str,
+ query: &HeaderMap,
+ headers: &HeaderMap,
+ mut signed_headers: Vec<HeaderName>,
content_sha256: &str,
-) -> String {
+) -> Result<String, Error> {
// 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
@@ -268,49 +239,52 @@ pub fn canonical_request(
// 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()
+ let canonical_uri: std::borrow::Cow<str> = if service != "s3" {
+ uri_encode(canonical_uri, false).into()
} else {
- uri.path().into()
+ canonical_uri.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<_>>();
+ // Canonical query string from passed HeaderMap
+ let canonical_query_string = {
+ let mut items = Vec::with_capacity(query.len());
+ for (key, value) in query.iter() {
+ let value = std::str::from_utf8(value.as_bytes())?;
+ items.push(uri_encode(key.as_str(), true) + "=" + &uri_encode(value, true));
+ }
items.sort();
items.join("&")
- } else {
- "".to_string()
- }
+ };
+
+ // Canonical header string calculated from signed headers
+ signed_headers.sort_by(|h1, h2| h1.as_str().cmp(h2.as_str()));
+ let canonical_header_string = {
+ let mut items = Vec::with_capacity(signed_headers.len());
+ for name in signed_headers.iter() {
+ let value = headers
+ .get(name)
+ .ok_or_bad_request(format!("signed header `{}` is not present", name))?
+ .to_str()?;
+ items.push((name, value));
+ }
+ items
+ .iter()
+ .map(|(key, value)| format!("{}:{}", key.as_str(), value.trim()))
+ .collect::<Vec<_>>()
+ .join("\n")
+ };
+ let signed_headers = signed_headers.join(";");
+
+ let list = [
+ method.as_str(),
+ &canonical_uri,
+ &canonical_query_string,
+ &canonical_header_string,
+ "",
+ &signed_headers,
+ content_sha256,
+ ];
+ Ok(list.join("\n"))
}
pub fn parse_date(date: &str) -> Result<DateTime<Utc>, Error> {
@@ -322,28 +296,24 @@ pub fn parse_date(date: &str) -> Result<DateTime<Utc>, Error> {
pub async fn verify_v4(
garage: &Garage,
service: &str,
- credential: &str,
- date: &DateTime<Utc>,
- signature: &str,
+ auth: &Authorization,
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 scope_expected = compute_scope(&auth.date, &garage.config.s3_api.s3_region, service);
+ if auth.scope != scope_expected {
+ return Err(Error::AuthorizationHeaderMalformed(auth.scope.to_string()));
}
let key = garage
.key_table
- .get(&EmptyKey, &key_id)
+ .get(&EmptyKey, &auth.key_id)
.await?
.filter(|k| !k.state.is_deleted())
- .ok_or_else(|| Error::forbidden(format!("No such key: {}", &key_id)))?;
+ .ok_or_else(|| Error::forbidden(format!("No such key: {}", &auth.key_id)))?;
let key_p = key.params().unwrap();
let mut hmac = signing_hmac(
- date,
+ &auth.date,
&key_p.secret_key,
&garage.config.s3_api.s3_region,
service,
@@ -351,9 +321,179 @@ pub async fn verify_v4(
.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 {
+ if auth.signature != our_signature {
return Err(Error::forbidden("Invalid signature".to_string()));
}
Ok(key)
}
+
+// ============ Authorization header, or X-Amz-* query params =========
+
+pub struct Authorization {
+ key_id: String,
+ scope: String,
+ signed_headers: String,
+ signature: String,
+ content_sha256: String,
+ date: DateTime<Utc>,
+}
+
+impl Authorization {
+ fn parse(headers: &HeaderMap) -> Result<Self, Error> {
+ let authorization = headers
+ .get(AUTHORIZATION)
+ .ok_or_bad_request("Missing authorization header")?
+ .to_str()?;
+
+ let (auth_kind, rest) = authorization
+ .split_once(' ')
+ .ok_or_bad_request("Authorization field to short")?;
+
+ 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 signed_headers = auth_params
+ .get("SignedHeaders")
+ .ok_or_bad_request("Could not find SignedHeaders in Authorization field")?
+ .to_string();
+ let signature = auth_params
+ .get("Signature")
+ .ok_or_bad_request("Could not find Signature in Authorization field")?
+ .to_string();
+
+ let content_sha256 = headers
+ .get(X_AMZ_CONTENT_SH256)
+ .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)?
+ .to_str()?;
+ let date = parse_date(date)?;
+
+ if Utc::now() - date > Duration::hours(24) {
+ return Err(Error::bad_request("Date is too old".to_string()));
+ }
+
+ let (key_id, scope) = parse_credential(cred)?;
+ let auth = Authorization {
+ key_id,
+ scope,
+ signed_headers,
+ signature,
+ content_sha256: content_sha256.to_str()?.to_string(),
+ date,
+ };
+ Ok(auth)
+ }
+
+ fn parse_presigned(algorithm: &str, query: &HeaderMap) -> Result<Self, Error> {
+ if algorithm != AWS4_HMAC_SHA256 {
+ return Err(Error::bad_request(
+ "Unsupported authorization method".to_string(),
+ ));
+ }
+
+ let cred = query
+ .get(X_AMZ_CREDENTIAL)
+ .ok_or_bad_request("X-Amz-Credential not found in query parameters")?;
+ let signed_headers = query
+ .get(X_AMZ_SIGNEDHEADERS)
+ .ok_or_bad_request("X-Amz-SignedHeaders not found in query parameters")?;
+ let signature = query
+ .get(X_AMZ_SIGNATURE)
+ .ok_or_bad_request("X-Amz-Signature not found in query parameters")?;
+
+ let duration = query
+ .get(X_AMZ_EXPIRES)
+ .ok_or_bad_request("X-Amz-Expires not found in query parameters")?
+ .to_str()?
+ .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 = query
+ .get(X_AMZ_DATE)
+ .ok_or_bad_request("Missing X-Amz-Date field")?
+ .to_str()?;
+ let date = parse_date(date)?;
+
+ if Utc::now() - date > Duration::seconds(duration) {
+ return Err(Error::bad_request("Date is too old".to_string()));
+ }
+
+ let (key_id, scope) = parse_credential(cred.to_str()?)?;
+ Ok(Authorization {
+ key_id,
+ scope,
+ signed_headers: signed_headers.to_str()?.to_string(),
+ signature: signature.to_str()?.to_string(),
+ content_sha256: UNSIGNED_PAYLOAD.to_string(),
+ date,
+ })
+ }
+
+ pub(crate) fn parse_form(params: &HeaderMap) -> Result<Self, Error> {
+ let credential = params
+ .get(X_AMZ_CREDENTIAL)
+ .ok_or_else(|| Error::forbidden("Garage does not support anonymous access yet"))?
+ .to_str()?;
+ let signature = params
+ .get(X_AMZ_SIGNATURE)
+ .ok_or_bad_request("No signature was provided")?
+ .to_str()?
+ .to_string();
+ let date = params
+ .get(X_AMZ_DATE)
+ .ok_or_bad_request("No date was provided")?
+ .to_str()?;
+ let date = parse_date(date)?;
+
+ if Utc::now() - date > Duration::hours(24) {
+ return Err(Error::bad_request("Date is too old".to_string()));
+ }
+
+ let (key_id, scope) = parse_credential(credential)?;
+ let auth = Authorization {
+ key_id,
+ scope,
+ signed_headers: "".to_string(),
+ signature,
+ content_sha256: UNSIGNED_PAYLOAD.to_string(),
+ date,
+ };
+ Ok(auth)
+ }
+}
+
+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(),
+ ))
+}