Add Identity Credential HAL, default implementation, and VTS tests.

IIdentityCredentialStore provides an interface to a secure store for
user identity documents.  This HAL is deliberately fairly general and
abstract.  To the extent possible, specification of the message
formats and semantics of communication with credential verification
devices and issuing authorities (IAs) is out of scope for this HAL.

It provides the interface with secure storage but a
credential-specific Android application will be required to implement
the presentation and verification protocols and processes appropriate
for the specific credential type.

Bug: 111446262
Test: VtsHalIdentityCredentialTargetTest
Test: android.hardware.identity-support-lib-test
Test: CtsIdentityTestCases
Change-Id: I64eb50114d645dd475012ad1b889d2177aaf1d37

1 files changed, 225 insertions, 0 deletions

diff --git a/identity/support/src/cppbor.cpp b/identity/support/src/cppbor.cpp
new file mode 100644
index 0000000000..d289985175
--- /dev/null
+++ b/identity/support/src/cppbor.cpp
@@ -0,0 +1,225 @@
+/*
+ * Copyright (c) 2019, 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 "cppbor.h"
+#include "cppbor_parse.h"
+
+#define LOG_TAG "CppBor"
+#include <android-base/logging.h>
+
+namespace cppbor {
+
+namespace {
+
+template <typename T, typename Iterator, typename = std::enable_if<std::is_unsigned<T>::value>>
+Iterator writeBigEndian(T value, Iterator pos) {
+    for (unsigned i = 0; i < sizeof(value); ++i) {
+        *pos++ = static_cast<uint8_t>(value >> (8 * (sizeof(value) - 1)));
+        value = static_cast<T>(value << 8);
+    }
+    return pos;
+}
+
+template <typename T, typename = std::enable_if<std::is_unsigned<T>::value>>
+void writeBigEndian(T value, std::function<void(uint8_t)>& cb) {
+    for (unsigned i = 0; i < sizeof(value); ++i) {
+        cb(static_cast<uint8_t>(value >> (8 * (sizeof(value) - 1))));
+        value = static_cast<T>(value << 8);
+    }
+}
+
+}  // namespace
+
+size_t headerSize(uint64_t addlInfo) {
+    if (addlInfo < ONE_BYTE_LENGTH) return 1;
+    if (addlInfo <= std::numeric_limits<uint8_t>::max()) return 2;
+    if (addlInfo <= std::numeric_limits<uint16_t>::max()) return 3;
+    if (addlInfo <= std::numeric_limits<uint32_t>::max()) return 5;
+    return 9;
+}
+
+uint8_t* encodeHeader(MajorType type, uint64_t addlInfo, uint8_t* pos, const uint8_t* end) {
+    size_t sz = headerSize(addlInfo);
+    if (end - pos < static_cast<ssize_t>(sz)) return nullptr;
+    switch (sz) {
+        case 1:
+            *pos++ = type | static_cast<uint8_t>(addlInfo);
+            return pos;
+        case 2:
+            *pos++ = type | ONE_BYTE_LENGTH;
+            *pos++ = static_cast<uint8_t>(addlInfo);
+            return pos;
+        case 3:
+            *pos++ = type | TWO_BYTE_LENGTH;
+            return writeBigEndian(static_cast<uint16_t>(addlInfo), pos);
+        case 5:
+            *pos++ = type | FOUR_BYTE_LENGTH;
+            return writeBigEndian(static_cast<uint32_t>(addlInfo), pos);
+        case 9:
+            *pos++ = type | EIGHT_BYTE_LENGTH;
+            return writeBigEndian(addlInfo, pos);
+        default:
+            CHECK(false);  // Impossible to get here.
+            return nullptr;
+    }
+}
+
+void encodeHeader(MajorType type, uint64_t addlInfo, EncodeCallback encodeCallback) {
+    size_t sz = headerSize(addlInfo);
+    switch (sz) {
+        case 1:
+            encodeCallback(type | static_cast<uint8_t>(addlInfo));
+            break;
+        case 2:
+            encodeCallback(type | ONE_BYTE_LENGTH);
+            encodeCallback(static_cast<uint8_t>(addlInfo));
+            break;
+        case 3:
+            encodeCallback(type | TWO_BYTE_LENGTH);
+            writeBigEndian(static_cast<uint16_t>(addlInfo), encodeCallback);
+            break;
+        case 5:
+            encodeCallback(type | FOUR_BYTE_LENGTH);
+            writeBigEndian(static_cast<uint32_t>(addlInfo), encodeCallback);
+            break;
+        case 9:
+            encodeCallback(type | EIGHT_BYTE_LENGTH);
+            writeBigEndian(addlInfo, encodeCallback);
+            break;
+        default:
+            CHECK(false);  // Impossible to get here.
+    }
+}
+
+bool Item::operator==(const Item& other) const& {
+    if (type() != other.type()) return false;
+    switch (type()) {
+        case UINT:
+            return *asUint() == *(other.asUint());
+        case NINT:
+            return *asNint() == *(other.asNint());
+        case BSTR:
+            return *asBstr() == *(other.asBstr());
+        case TSTR:
+            return *asTstr() == *(other.asTstr());
+        case ARRAY:
+            return *asArray() == *(other.asArray());
+        case MAP:
+            return *asMap() == *(other.asMap());
+        case SIMPLE:
+            return *asSimple() == *(other.asSimple());
+        case SEMANTIC:
+            return *asSemantic() == *(other.asSemantic());
+        default:
+            CHECK(false);  // Impossible to get here.
+            return false;
+    }
+}
+
+Nint::Nint(int64_t v) : mValue(v) {
+    CHECK(v < 0) << "Only negative values allowed";
+}
+
+bool Simple::operator==(const Simple& other) const& {
+    if (simpleType() != other.simpleType()) return false;
+
+    switch (simpleType()) {
+        case BOOLEAN:
+            return *asBool() == *(other.asBool());
+        case NULL_T:
+            return true;
+        default:
+            CHECK(false);  // Impossible to get here.
+            return false;
+    }
+}
+
+uint8_t* Bstr::encode(uint8_t* pos, const uint8_t* end) const {
+    pos = encodeHeader(mValue.size(), pos, end);
+    if (!pos || end - pos < static_cast<ptrdiff_t>(mValue.size())) return nullptr;
+    return std::copy(mValue.begin(), mValue.end(), pos);
+}
+
+void Bstr::encodeValue(EncodeCallback encodeCallback) const {
+    for (auto c : mValue) {
+        encodeCallback(c);
+    }
+}
+
+uint8_t* Tstr::encode(uint8_t* pos, const uint8_t* end) const {
+    pos = encodeHeader(mValue.size(), pos, end);
+    if (!pos || end - pos < static_cast<ptrdiff_t>(mValue.size())) return nullptr;
+    return std::copy(mValue.begin(), mValue.end(), pos);
+}
+
+void Tstr::encodeValue(EncodeCallback encodeCallback) const {
+    for (auto c : mValue) {
+        encodeCallback(static_cast<uint8_t>(c));
+    }
+}
+
+bool CompoundItem::operator==(const CompoundItem& other) const& {
+    return type() == other.type()             //
+           && addlInfo() == other.addlInfo()  //
+           // Can't use vector::operator== because the contents are pointers.  std::equal lets us
+           // provide a predicate that does the dereferencing.
+           && std::equal(mEntries.begin(), mEntries.end(), other.mEntries.begin(),
+                         [](auto& a, auto& b) -> bool { return *a == *b; });
+}
+
+uint8_t* CompoundItem::encode(uint8_t* pos, const uint8_t* end) const {
+    pos = encodeHeader(addlInfo(), pos, end);
+    if (!pos) return nullptr;
+    for (auto& entry : mEntries) {
+        pos = entry->encode(pos, end);
+        if (!pos) return nullptr;
+    }
+    return pos;
+}
+
+void CompoundItem::encode(EncodeCallback encodeCallback) const {
+    encodeHeader(addlInfo(), encodeCallback);
+    for (auto& entry : mEntries) {
+        entry->encode(encodeCallback);
+    }
+}
+
+void Map::assertInvariant() const {
+    CHECK(mEntries.size() % 2 == 0);
+}
+
+std::unique_ptr<Item> Map::clone() const {
+    assertInvariant();
+    auto res = std::make_unique<Map>();
+    for (size_t i = 0; i < mEntries.size(); i += 2) {
+        res->add(mEntries[i]->clone(), mEntries[i + 1]->clone());
+    }
+    return res;
+}
+
+std::unique_ptr<Item> Array::clone() const {
+    auto res = std::make_unique<Array>();
+    for (size_t i = 0; i < mEntries.size(); i++) {
+        res->add(mEntries[i]->clone());
+    }
+    return res;
+}
+
+void Semantic::assertInvariant() const {
+    CHECK(mEntries.size() == 1);
+}
+
+}  // namespace cppbor