From c75ac31ec97c9a6116403355bc61e3976fe44074 Mon Sep 17 00:00:00 2001 From: David Zeuthen Date: Mon, 28 Oct 2019 13:16:45 -0400 Subject: 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 --- identity/support/src/cppbor_parse.cpp | 351 ++++++++++++++++++++++++++++++++++ 1 file changed, 351 insertions(+) create mode 100644 identity/support/src/cppbor_parse.cpp (limited to 'identity/support/src/cppbor_parse.cpp') diff --git a/identity/support/src/cppbor_parse.cpp b/identity/support/src/cppbor_parse.cpp new file mode 100644 index 0000000000..c9ebb8ac1a --- /dev/null +++ b/identity/support/src/cppbor_parse.cpp @@ -0,0 +1,351 @@ +/* + * 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_parse.h" + +#include +#include + +#define LOG_TAG "CppBor" +#include + +namespace cppbor { + +namespace { + +std::string insufficientLengthString(size_t bytesNeeded, size_t bytesAvail, + const std::string& type) { + std::stringstream errStream; + errStream << "Need " << bytesNeeded << " byte(s) for " << type << ", have " << bytesAvail + << "."; + return errStream.str(); +} + +template >> +std::tuple parseLength(const uint8_t* pos, const uint8_t* end, + ParseClient* parseClient) { + if (pos + sizeof(T) > end) { + parseClient->error(pos - 1, insufficientLengthString(sizeof(T), end - pos, "length field")); + return {false, 0, pos}; + } + + const uint8_t* intEnd = pos + sizeof(T); + T result = 0; + do { + result = static_cast((result << 8) | *pos++); + } while (pos < intEnd); + return {true, result, pos}; +} + +std::tuple parseRecursively(const uint8_t* begin, const uint8_t* end, + ParseClient* parseClient); + +std::tuple handleUint(uint64_t value, const uint8_t* hdrBegin, + const uint8_t* hdrEnd, + ParseClient* parseClient) { + std::unique_ptr item = std::make_unique(value); + return {hdrEnd, + parseClient->item(item, hdrBegin, hdrEnd /* valueBegin */, hdrEnd /* itemEnd */)}; +} + +std::tuple handleNint(uint64_t value, const uint8_t* hdrBegin, + const uint8_t* hdrEnd, + ParseClient* parseClient) { + if (value > std::numeric_limits::max()) { + parseClient->error(hdrBegin, "NINT values that don't fit in int64_t are not supported."); + return {hdrBegin, nullptr /* end parsing */}; + } + std::unique_ptr item = std::make_unique(-1 - static_cast(value)); + return {hdrEnd, + parseClient->item(item, hdrBegin, hdrEnd /* valueBegin */, hdrEnd /* itemEnd */)}; +} + +std::tuple handleBool(uint64_t value, const uint8_t* hdrBegin, + const uint8_t* hdrEnd, + ParseClient* parseClient) { + std::unique_ptr item = std::make_unique(value == TRUE); + return {hdrEnd, + parseClient->item(item, hdrBegin, hdrEnd /* valueBegin */, hdrEnd /* itemEnd */)}; +} + +std::tuple handleNull(const uint8_t* hdrBegin, const uint8_t* hdrEnd, + ParseClient* parseClient) { + std::unique_ptr item = std::make_unique(); + return {hdrEnd, + parseClient->item(item, hdrBegin, hdrEnd /* valueBegin */, hdrEnd /* itemEnd */)}; +} + +template +std::tuple handleString(uint64_t length, const uint8_t* hdrBegin, + const uint8_t* valueBegin, const uint8_t* end, + const std::string& errLabel, + ParseClient* parseClient) { + if (end - valueBegin < static_cast(length)) { + parseClient->error(hdrBegin, insufficientLengthString(length, end - valueBegin, errLabel)); + return {hdrBegin, nullptr /* end parsing */}; + } + + std::unique_ptr item = std::make_unique(valueBegin, valueBegin + length); + return {valueBegin + length, + parseClient->item(item, hdrBegin, valueBegin, valueBegin + length)}; +} + +class IncompleteItem { + public: + virtual ~IncompleteItem() {} + virtual void add(std::unique_ptr item) = 0; +}; + +class IncompleteArray : public Array, public IncompleteItem { + public: + IncompleteArray(size_t size) : mSize(size) {} + + // We return the "complete" size, rather than the actual size. + size_t size() const override { return mSize; } + + void add(std::unique_ptr item) override { + mEntries.reserve(mSize); + mEntries.push_back(std::move(item)); + } + + private: + size_t mSize; +}; + +class IncompleteMap : public Map, public IncompleteItem { + public: + IncompleteMap(size_t size) : mSize(size) {} + + // We return the "complete" size, rather than the actual size. + size_t size() const override { return mSize; } + + void add(std::unique_ptr item) override { + mEntries.reserve(mSize * 2); + mEntries.push_back(std::move(item)); + } + + private: + size_t mSize; +}; + +class IncompleteSemantic : public Semantic, public IncompleteItem { + public: + IncompleteSemantic(uint64_t value) : Semantic(value) {} + + // We return the "complete" size, rather than the actual size. + size_t size() const override { return 1; } + + void add(std::unique_ptr item) override { + mEntries.reserve(1); + mEntries.push_back(std::move(item)); + } +}; + +std::tuple handleEntries(size_t entryCount, const uint8_t* hdrBegin, + const uint8_t* pos, const uint8_t* end, + const std::string& typeName, + ParseClient* parseClient) { + while (entryCount > 0) { + --entryCount; + if (pos == end) { + parseClient->error(hdrBegin, "Not enough entries for " + typeName + "."); + return {hdrBegin, nullptr /* end parsing */}; + } + std::tie(pos, parseClient) = parseRecursively(pos, end, parseClient); + if (!parseClient) return {hdrBegin, nullptr}; + } + return {pos, parseClient}; +} + +std::tuple handleCompound( + std::unique_ptr item, uint64_t entryCount, const uint8_t* hdrBegin, + const uint8_t* valueBegin, const uint8_t* end, const std::string& typeName, + ParseClient* parseClient) { + parseClient = + parseClient->item(item, hdrBegin, valueBegin, valueBegin /* don't know the end yet */); + if (!parseClient) return {hdrBegin, nullptr}; + + const uint8_t* pos; + std::tie(pos, parseClient) = + handleEntries(entryCount, hdrBegin, valueBegin, end, typeName, parseClient); + if (!parseClient) return {hdrBegin, nullptr}; + + return {pos, parseClient->itemEnd(item, hdrBegin, valueBegin, pos)}; +} + +std::tuple parseRecursively(const uint8_t* begin, const uint8_t* end, + ParseClient* parseClient) { + const uint8_t* pos = begin; + + MajorType type = static_cast(*pos & 0xE0); + uint8_t tagInt = *pos & 0x1F; + ++pos; + + bool success = true; + uint64_t addlData; + if (tagInt < ONE_BYTE_LENGTH || tagInt > EIGHT_BYTE_LENGTH) { + addlData = tagInt; + } else { + switch (tagInt) { + case ONE_BYTE_LENGTH: + std::tie(success, addlData, pos) = parseLength(pos, end, parseClient); + break; + + case TWO_BYTE_LENGTH: + std::tie(success, addlData, pos) = parseLength(pos, end, parseClient); + break; + + case FOUR_BYTE_LENGTH: + std::tie(success, addlData, pos) = parseLength(pos, end, parseClient); + break; + + case EIGHT_BYTE_LENGTH: + std::tie(success, addlData, pos) = parseLength(pos, end, parseClient); + break; + + default: + CHECK(false); // It's impossible to get here + break; + } + } + + if (!success) return {begin, nullptr}; + + switch (type) { + case UINT: + return handleUint(addlData, begin, pos, parseClient); + + case NINT: + return handleNint(addlData, begin, pos, parseClient); + + case BSTR: + return handleString(addlData, begin, pos, end, "byte string", parseClient); + + case TSTR: + return handleString(addlData, begin, pos, end, "text string", parseClient); + + case ARRAY: + return handleCompound(std::make_unique(addlData), addlData, begin, pos, + end, "array", parseClient); + + case MAP: + return handleCompound(std::make_unique(addlData), addlData * 2, begin, + pos, end, "map", parseClient); + + case SEMANTIC: + return handleCompound(std::make_unique(addlData), 1, begin, pos, + end, "semantic", parseClient); + + case SIMPLE: + switch (addlData) { + case TRUE: + case FALSE: + return handleBool(addlData, begin, pos, parseClient); + case NULL_V: + return handleNull(begin, pos, parseClient); + } + } + CHECK(false); // Impossible to get here. + return {}; +} + +class FullParseClient : public ParseClient { + public: + virtual ParseClient* item(std::unique_ptr& item, const uint8_t*, const uint8_t*, + const uint8_t* end) override { + if (mParentStack.empty() && !item->isCompound()) { + // This is the first and only item. + mTheItem = std::move(item); + mPosition = end; + return nullptr; // We're done. + } + + if (item->isCompound()) { + // Starting a new compound data item, i.e. a new parent. Save it on the parent stack. + // It's safe to save a raw pointer because the unique_ptr is guaranteed to stay in + // existence until the corresponding itemEnd() call. + assert(dynamic_cast(item.get())); + mParentStack.push(static_cast(item.get())); + return this; + } else { + appendToLastParent(std::move(item)); + return this; + } + } + + virtual ParseClient* itemEnd(std::unique_ptr& item, const uint8_t*, const uint8_t*, + const uint8_t* end) override { + CHECK(item->isCompound() && item.get() == mParentStack.top()); + mParentStack.pop(); + + if (mParentStack.empty()) { + mTheItem = std::move(item); + mPosition = end; + return nullptr; // We're done + } else { + appendToLastParent(std::move(item)); + return this; + } + } + + virtual void error(const uint8_t* position, const std::string& errorMessage) override { + mPosition = position; + mErrorMessage = errorMessage; + } + + std::tuple /* result */, const uint8_t* /* newPos */, + std::string /* errMsg */> + parseResult() { + std::unique_ptr p = std::move(mTheItem); + return {std::move(p), mPosition, std::move(mErrorMessage)}; + } + + private: + void appendToLastParent(std::unique_ptr item) { + auto parent = mParentStack.top(); + assert(dynamic_cast(parent)); + if (parent->type() == ARRAY) { + static_cast(parent)->add(std::move(item)); + } else if (parent->type() == MAP) { + static_cast(parent)->add(std::move(item)); + } else if (parent->type() == SEMANTIC) { + static_cast(parent)->add(std::move(item)); + } else { + CHECK(false); // Impossible to get here. + } + } + + std::unique_ptr mTheItem; + std::stack mParentStack; + const uint8_t* mPosition = nullptr; + std::string mErrorMessage; +}; + +} // anonymous namespace + +void parse(const uint8_t* begin, const uint8_t* end, ParseClient* parseClient) { + parseRecursively(begin, end, parseClient); +} + +std::tuple /* result */, const uint8_t* /* newPos */, + std::string /* errMsg */> +parse(const uint8_t* begin, const uint8_t* end) { + FullParseClient parseClient; + parse(begin, end, &parseClient); + return parseClient.parseResult(); +} + +} // namespace cppbor -- cgit v1.2.3