From 8228784be04ff506d97941ae28368a8e48c61ff7 Mon Sep 17 00:00:00 2001
From: Radoslaw Zarzynski <rzarzyns@redhat.com>
Date: Mon, 17 Jul 2017 08:39:13 -0400
Subject: [PATCH] rgw: add support for Swift's TempURLs with prefix-based
 scope.

Fixes: http://tracker.ceph.com/issues/20398
Signed-off-by: Radoslaw Zarzynski <rzarzyns@redhat.com>
---
 src/rgw/rgw_swift_auth.cc | 69 +++++++++++++++++++++++++++++++++++++--
 src/rgw/rgw_swift_auth.h  |  1 +
 2 files changed, 67 insertions(+), 3 deletions(-)

diff --git a/src/rgw/rgw_swift_auth.cc b/src/rgw/rgw_swift_auth.cc
index 39c80f0d4b1a9..525671c34b4ad 100644
--- a/src/rgw/rgw_swift_auth.cc
+++ b/src/rgw/rgw_swift_auth.cc
@@ -5,6 +5,8 @@
 
 #include <boost/utility/string_view.hpp>
 #include <boost/container/static_vector.hpp>
+#include <boost/algorithm/string/predicate.hpp>
+#include <boost/algorithm/string.hpp>
 
 #include "rgw_swift_auth.h"
 #include "rgw_rest.h"
@@ -190,6 +192,53 @@ public:
 
 }; /* TempURLEngine::SignatureHelper */
 
+class TempURLEngine::PrefixableSignatureHelper
+    : private TempURLEngine::SignatureHelper {
+  using base_t = SignatureHelper;
+
+  const boost::string_view decoded_uri;
+  const boost::string_view object_name;
+  boost::string_view no_obj_uri;
+
+  const boost::optional<const std::string&> prefix;
+
+public:
+  PrefixableSignatureHelper(const std::string& decoded_uri,
+	                    const std::string& object_name,
+                            const boost::optional<const std::string&> prefix)
+    : decoded_uri(decoded_uri),
+      object_name(object_name),
+      prefix(prefix) {
+    /* Transform: v1/acct/cont/obj - > v1/acct/cont/ */
+    no_obj_uri = \
+      decoded_uri.substr(0, decoded_uri.length() - object_name.length());
+  }
+
+  const char* calc(const std::string& key,
+                   const boost::string_view& method,
+                   const boost::string_view& path,
+                   const std::string& expires) {
+    if (!prefix) {
+      return base_t::calc(key, method, path, expires);
+    } else {
+      const auto prefixed_path = \
+        string_cat_reserve("prefix:", no_obj_uri, *prefix);
+      return base_t::calc(key, method, prefixed_path, expires);
+    }
+  }
+
+  bool is_equal_to(const std::string& rhs) const {
+    bool is_auth_ok = base_t::is_equal_to(rhs);
+
+    if (prefix && is_auth_ok) {
+      const auto prefix_uri = string_cat_reserve(no_obj_uri, *prefix);
+      is_auth_ok = boost::algorithm::starts_with(decoded_uri, prefix_uri);
+    }
+
+    return is_auth_ok;
+  }
+}; /* TempURLEngine::PrefixableSignatureHelper */
+
 TempURLEngine::result_t
 TempURLEngine::authenticate(const req_state* const s) const
 {
@@ -197,13 +246,22 @@ TempURLEngine::authenticate(const req_state* const s) const
     return result_t::deny();
   }
 
-  const string& temp_url_sig = s->info.args.get("temp_url_sig");
-  const string& temp_url_expires = s->info.args.get("temp_url_expires");
+  /* NOTE(rzarzynski): RGWHTTPArgs::get(), in contrast to RGWEnv::get(),
+   * never returns nullptr. If the requested parameter is absent, we will
+   * get the empty string. */
+  const std::string& temp_url_sig = s->info.args.get("temp_url_sig");
+  const std::string& temp_url_expires = s->info.args.get("temp_url_expires");
 
   if (temp_url_sig.empty() || temp_url_expires.empty()) {
     return result_t::deny();
   }
 
+  /* Though, for prefixed tempurls we need to differentiate between empty
+   * prefix and lack of prefix. Empty prefix means allowance for whole
+   * container. */
+  const boost::optional<const std::string&> temp_url_prefix = \
+    s->info.args.get_optional("temp_url_prefix");
+
   RGWUserInfo owner_info;
   try {
     get_owner_info(s, owner_info);
@@ -250,7 +308,12 @@ TempURLEngine::authenticate(const req_state* const s) const
   }
 
   /* Need to try each combination of keys, allowed path and methods. */
-  SignatureHelper sig_helper;
+  PrefixableSignatureHelper sig_helper {
+    s->decoded_uri,
+    s->object.name,
+    temp_url_prefix
+  };
+
   for (const auto& kv : owner_info.temp_url_keys) {
     const int temp_url_key_num = kv.first;
     const string& temp_url_key = kv.second;
diff --git a/src/rgw/rgw_swift_auth.h b/src/rgw/rgw_swift_auth.h
index 055d541d3273a..afab8e069745a 100644
--- a/src/rgw/rgw_swift_auth.h
+++ b/src/rgw/rgw_swift_auth.h
@@ -49,6 +49,7 @@ class TempURLEngine : public rgw::auth::Engine {
   bool is_expired(const std::string& expires) const;
 
   class SignatureHelper;
+  class PrefixableSignatureHelper;
 
 public:
   TempURLEngine(CephContext* const cct,
-- 
2.39.5