Add confirmation UI support libaray
Includes:
A light weight CBOR generator
This patch adds a header only CBOR generator and unit tests.
It allows expressing CBOR datastructures in C++ for subsequent
serialization. The implementation performs no memory allocation
and only depends on stdint.h (for (u)intx_t) and stddefs.h (for size_t).
It is tailored for use in constrained environments such as TEEs.
Convenience method for generating a SHA256 HMAC
Bug: 63928580
Test: android.hardware.confirmationui@support-lib-tests
Change-Id: I1d93a85503f861281e71e09b1ede5cbb74219694
diff --git a/confirmationui/support/src/cbor.cpp b/confirmationui/support/src/cbor.cpp
new file mode 100644
index 0000000..e7ea164
--- /dev/null
+++ b/confirmationui/support/src/cbor.cpp
@@ -0,0 +1,111 @@
+/*
+**
+** Copyright 2017, The Android Open Source Project
+**
+** 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.
+*/
+
+#include <android/hardware/confirmationui/support/cbor.h>
+
+namespace android {
+namespace hardware {
+namespace confirmationui {
+namespace support {
+namespace {
+
+inline uint8_t getByte(const uint64_t& v, const uint8_t index) {
+ return v >> (index * 8);
+}
+
+WriteState writeBytes(WriteState state, uint64_t value, uint8_t size) {
+ auto pos = state.data_;
+ if (!(state += size)) return state;
+ switch (size) {
+ case 8:
+ *pos++ = getByte(value, 7);
+ *pos++ = getByte(value, 6);
+ *pos++ = getByte(value, 5);
+ *pos++ = getByte(value, 4);
+ case 4:
+ *pos++ = getByte(value, 3);
+ *pos++ = getByte(value, 2);
+ case 2:
+ *pos++ = getByte(value, 1);
+ case 1:
+ *pos++ = value;
+ break;
+ default:
+ state.error_ = Error::MALFORMED;
+ }
+ return state;
+}
+
+} // anonymous namespace
+
+WriteState writeHeader(WriteState wState, Type type, const uint64_t value) {
+ if (!wState) return wState;
+ uint8_t& header = *wState.data_;
+ if (!++wState) return wState;
+ header = static_cast<uint8_t>(type) << 5;
+ if (value < 24) {
+ header |= static_cast<uint8_t>(value);
+ } else if (value < 0x100) {
+ header |= 24;
+ wState = writeBytes(wState, value, 1);
+ } else if (value < 0x10000) {
+ header |= 25;
+ wState = writeBytes(wState, value, 2);
+ } else if (value < 0x100000000) {
+ header |= 26;
+ wState = writeBytes(wState, value, 4);
+ } else {
+ header |= 27;
+ wState = writeBytes(wState, value, 8);
+ }
+ return wState;
+}
+
+bool checkUTF8Copy(const char* begin, const char* const end, uint8_t* out) {
+ uint32_t multi_byte_length = 0;
+ while (begin != end) {
+ if (multi_byte_length) {
+ // parsing multi byte character - must start with 10xxxxxx
+ --multi_byte_length;
+ if ((*begin & 0xc0) != 0x80) return false;
+ } else if (!((*begin) & 0x80)) {
+ // 7bit character -> nothing to be done
+ } else {
+ // msb is set and we were not parsing a multi byte character
+ // so this must be a header byte
+ char c = *begin << 1;
+ while (c & 0x80) {
+ ++multi_byte_length;
+ c <<= 1;
+ }
+ // headers of the form 10xxxxxx are not allowed
+ if (multi_byte_length < 1) return false;
+ // chars longer than 4 bytes are not allowed (multi_byte_length does not count the
+ // header thus > 3
+ if (multi_byte_length > 3) return false;
+ }
+ if (out) *out++ = *reinterpret_cast<const uint8_t*>(begin++);
+ }
+ // if the string ends in the middle of a multi byte char it is invalid
+ if (multi_byte_length) return false;
+ return true;
+}
+
+} // namespace support
+} // namespace confirmationui
+} // namespace hardware
+} // namespace android
diff --git a/confirmationui/support/src/confirmationui_utils.cpp b/confirmationui/support/src/confirmationui_utils.cpp
new file mode 100644
index 0000000..708f0d56
--- /dev/null
+++ b/confirmationui/support/src/confirmationui_utils.cpp
@@ -0,0 +1,39 @@
+/*
+**
+** Copyright 2017, The Android Open Source Project
+**
+** 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.
+*/
+
+#include <android/hardware/confirmationui/support/confirmationui_utils.h>
+
+namespace android {
+namespace hardware {
+namespace confirmationui {
+namespace support {
+
+bool operator==(const ByteBufferProxy& lhs, const ByteBufferProxy& rhs) {
+ if (lhs.size() == rhs.size()) {
+ auto lhsi = lhs.begin();
+ auto rhsi = rhs.begin();
+ while (lhsi != lhs.end()) {
+ if (*lhsi++ != *rhsi++) return false;
+ }
+ }
+ return true;
+}
+
+} // namespace support
+} // namespace confirmationui
+} // namespace hardware
+} // namespace android