From 11966745c00000261dfc6345b44dc1a7d7fe8f71 Mon Sep 17 00:00:00 2001
From: sschmieg <sschmieg@google.com>
Date: Fri, 30 Aug 2019 13:27:07 -0700
Subject: [PATCH] Defining an interface for a StreamingMac primitive, returning
OutputStream that defer the computation until closed.
PiperOrigin-RevId: 266444142
---
cc/BUILD.bazel | 31 ++++++++++
cc/CMakeLists.txt | 23 +++++++
cc/output_stream_with_result.h | 110 +++++++++++++++++++++++++++++++++
cc/streaming_mac.h | 53 ++++++++++++++++
4 files changed, 217 insertions(+)
create mode 100644 cc/output_stream_with_result.h
create mode 100644 cc/streaming_mac.h
diff --git a/cc/BUILD.bazel b/cc/BUILD.bazel
index a13346625..0e93059fc 100644
--- a/cc/BUILD.bazel
+++ b/cc/BUILD.bazel
@@ -39,6 +39,7 @@ PUBLIC_APIS = [
"mac_config.h",
"mac_factory.h",
"mac_key_templates.h",
+ "output_stream_with_result.h",
"output_stream.h",
"public_key_sign.h",
"public_key_sign_factory.h",
@@ -51,6 +52,7 @@ PUBLIC_APIS = [
"streaming_aead.h",
"streaming_aead_config.h",
"streaming_aead_key_templates.h",
+ "streaming_mac.h",
"tink_config.h",
"version.h",
]
@@ -72,11 +74,13 @@ PUBLIC_API_DEPS = [
":keyset_writer",
":kms_client",
":mac",
+ ":output_stream_with_result",
":output_stream",
":primitive_set",
":public_key_sign",
":public_key_verify",
":streaming_aead",
+ ":streaming_mac",
":random_access_stream",
":registry",
":registry_impl",
@@ -159,6 +163,19 @@ cc_library(
],
)
+cc_library(
+ name = "output_stream_with_result",
+ hdrs = ["output_stream_with_result.h"],
+ include_prefix = "tink",
+ strip_include_prefix = "/cc",
+ visibility = ["//visibility:public"],
+ deps = [
+ ":output_stream",
+ "//cc/util:status",
+ "//cc/util:statusor",
+ ],
+)
+
cc_library(
name = "aead",
hdrs = ["aead.h"],
@@ -198,6 +215,20 @@ cc_library(
],
)
+cc_library(
+ name = "streaming_mac",
+ hdrs = ["streaming_mac.h"],
+ include_prefix = "tink",
+ strip_include_prefix = "/cc",
+ visibility = ["//visibility:public"],
+ deps = [
+ ":output_stream_with_result",
+ "//cc/util:status",
+ "//cc/util:statusor",
+ "@com_google_absl//absl/strings",
+ ],
+)
+
cc_library(
name = "hybrid_decrypt",
hdrs = ["hybrid_decrypt.h"],
diff --git a/cc/CMakeLists.txt b/cc/CMakeLists.txt
index 35d36ec13..0f4ffe336 100644
--- a/cc/CMakeLists.txt
+++ b/cc/CMakeLists.txt
@@ -46,6 +46,7 @@ set(TINK_PUBLIC_APIS
mac_config.h
mac_factory.h
mac_key_templates.h
+ output_stream_with_result.h
output_stream.h
public_key_sign.h
public_key_sign_factory.h
@@ -58,6 +59,7 @@ set(TINK_PUBLIC_APIS
streaming_aead.h
streaming_aead_config.h
streaming_aead_key_templates.h
+ streaming_mac.h
tink_config.h
"${TINK_VERSION_H}"
)
@@ -79,6 +81,7 @@ set(TINK_PUBLIC_API_DEPS
tink::core::keyset_reader
tink::core::keyset_writer
tink::core::kms_client
+ tink::core::output_stream_with_result
tink::core::output_stream
tink::core::public_key_sign
tink::core::public_key_verify
@@ -88,6 +91,7 @@ set(TINK_PUBLIC_API_DEPS
tink::core::registry
tink::core::registry_impl
tink::core::streaming_aead
+ tink::core::streaming_mac
tink::core::version
tink::aead::aead_config
tink::aead::aead_factory
@@ -155,6 +159,15 @@ tink_cc_library(
tink::util::statusor
)
+tink_cc_library(
+ NAME output_stream_with_result
+ SRCS output_stream_with_result.h
+ DEPS
+ tink::core::output_stream_with_result
+ tink::util::status
+ tink::util::statusor
+)
+
tink_cc_library(
NAME aead
SRCS aead.h
@@ -182,6 +195,16 @@ tink_cc_library(
absl::strings
)
+tink_cc_library(
+ NAME streaming_mac
+ SRCS streaming_mac.h
+ DEPS
+ tink::core::output_stream_with_result
+ tink::util::status
+ tink::util::statusor
+ absl::strings
+)
+
tink_cc_library(
NAME hybrid_decrypt
SRCS hybrid_decrypt.h
diff --git a/cc/output_stream_with_result.h b/cc/output_stream_with_result.h
new file mode 100644
index 000000000..01f330da0
--- /dev/null
+++ b/cc/output_stream_with_result.h
@@ -0,0 +1,110 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef TINK_OUTPUT_STREAM_WITH_RESULT_H_
+#define TINK_OUTPUT_STREAM_WITH_RESULT_H_
+
+#include <type_traits>
+
+#include "tink/output_stream.h"
+#include "tink/util/status.h"
+#include "tink/util/statusor.h"
+
+namespace crypto {
+namespace tink {
+
+// An abstract OutputStream subclass that acts as a sink for data and returns a
+// result after the stream has been closed.
+// The result is only available if the stream was able to close with an ok
+// status. Otherwise, the status of the GetResult call will be the same status
+// as the Close call had. If Close is successful, GetResult is guaranteed to
+// return a valid result.
+// The return type of GetResult will be StatusOr<T>, except for T == Status, in
+// which case the return type is Status.
+template <class T>
+class OutputStreamWithResult : public OutputStream {
+ public:
+ OutputStreamWithResult() : closed_(false) {}
+ ~OutputStreamWithResult() override {}
+
+ // The return type is StatusOr<T> if T != Status, and Status otherwise.
+ using ResultType =
+ typename std::conditional<std::is_same<T, util::Status>::value,
+ util::Status, util::StatusOr<T>>::type;
+
+ // Get the result associated with this OutputStream. Can only be called on
+ // closed streams, and will otherwise fail with FAILED_PRECONDITION as error
+ // code.
+ // If Close() returned an ok status, this method is guaranteed to contain a
+ // valid result.
+ // The return type is StatusOr<T> if T != Status, and Status otherwise.
+ ResultType GetResult() {
+ if (!closed_) {
+ return util::Status(util::error::FAILED_PRECONDITION,
+ "Stream is not closed");
+ }
+ return result_;
+ }
+
+ // Close the stream and return the computed result. Equivalent to calling
+ // Close() and GetResult() if Close() returned an OK status.
+ // The return type is StatusOr<T> if T != Status, and Status otherwise.
+ ResultType CloseAndGetResult() {
+ util::Status closing_status = Close();
+ if (!closing_status.ok()) {
+ return closing_status;
+ }
+ return GetResult();
+ }
+
+ // Closes the OutputStream.
+ util::Status Close() final {
+ if (closed_) {
+ return util::Status(util::error::FAILED_PRECONDITION, "Stream closed");
+ }
+ result_ = CloseStreamAndComputeResult();
+ closed_ = true;
+ return result_.status();
+ }
+
+ // Getting the next OutputStream buffer. See OutputStream for detailed
+ // description.
+ crypto::tink::util::StatusOr<int> Next(void** data) final {
+ if (closed_) {
+ return util::Status(util::error::FAILED_PRECONDITION,
+ "Write on closed Stream");
+ }
+ return NextBuffer(data);
+ }
+
+ protected:
+ // Compute the result for this OutputStream. Safe for thread safety problems,
+ // this method will only be called once.
+ // The return type is StatusOr<T> if T != Status, and Status otherwise.
+ virtual ResultType CloseStreamAndComputeResult() = 0;
+ // Getting the next OutputStream buffer. See OutputStream for detailed
+ // description.
+ virtual util::StatusOr<int> NextBuffer(void** data) = 0;
+
+ private:
+ bool closed_;
+ ResultType result_;
+};
+
+} // namespace tink
+} // namespace crypto
+
+#endif // TINK_OUTPUT_STREAM_WITH_RESULT_H_
diff --git a/cc/streaming_mac.h b/cc/streaming_mac.h
new file mode 100644
index 000000000..037b14895
--- /dev/null
+++ b/cc/streaming_mac.h
@@ -0,0 +1,53 @@
+// Copyright 2017 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef TINK_STREAMING_MAC_H_
+#define TINK_STREAMING_MAC_H_
+
+#include <memory>
+#include <string>
+
+#include "absl/strings/string_view.h"
+#include "tink/output_stream_with_result.h"
+#include "tink/util/status.h"
+#include "tink/util/statusor.h"
+
+namespace crypto {
+namespace tink {
+
+///////////////////////////////////////////////////////////////////////////////
+// Interface for Streaming MACs (Message Authentication Codes).
+// This interface should be used for authentication only, and not for other
+// purposes (e.g., it should not be used to generate pseudorandom bytes).
+class StreamingMac {
+ public:
+ // Returns an ComputeMacOutputStream, which when closed will return the
+ // message authentication code (MAC) of the data put into the stream.
+ virtual util::StatusOr<std::unique_ptr<OutputStreamWithResult<std::string>>>
+ NewComputeMacOutputStream() const = 0;
+
+ // Returns an VerifyMacOutputStream which verifies if 'mac' is a correct
+ // message authentication code (MAC) for the data written to it.
+ virtual util::StatusOr<std::unique_ptr<OutputStreamWithResult<util::Status>>>
+ NewVerifyMacOutputStream(const std::string& mac_value) const = 0;
+
+ virtual ~StreamingMac() {}
+};
+
+} // namespace tink
+} // namespace crypto
+
+#endif // TINK_STREAMING_MAC_H_
--
GitLab