rgw: Use correct secret key for POST authn

The POST authentication by signature validation looked up a user based
on the access key, then used the first secret key for the user. If the
access key used was not the first access key, then the expected
signature would be wrong, and the POST would be rejected.

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
(cherry picked from commit 586ad1f69e6260ef298805647911b3b49f8be7cf)

diff --git a/src/rgw/rgw_rest_s3.cc b/src/rgw/rgw_rest_s3.cc
index ba6b4e7f34c3a543097f7050efd64f3d089512e7..e8a10c1335d781ce3bece4c3481eea0da4c02d0a 100644 (file)
--- a/src/rgw/rgw_rest_s3.cc
+++ b/src/rgw/rgw_rest_s3.cc
@@ -964,7 +964,14 @@ int RGWPostObj_ObjStore_S3::get_policy()
 
     map<string, RGWAccessKey> access_keys  = user_info.access_keys;
 
-    map<string, RGWAccessKey>::const_iterator iter = access_keys.begin();
+    map<string, RGWAccessKey>::const_iterator iter = access_keys.find(s3_access_key);
+    // We know the key must exist, since the user was returned by
+    // rgw_get_user_info_by_access_key, but it doesn't hurt to check!
+    if (iter == access_keys.end()) {
+      ldout(s->cct, 0) << "Secret key lookup failed!" << dendl;
+      err_msg = "No secret key for matching access key";
+      return -EACCES;
+    }
     string s3_secret_key = (iter->second).key;
 
     char calc_signature[CEPH_CRYPTO_HMACSHA1_DIGESTSIZE];