diff --git a/keystore/Android.bp b/keystore/Android.bp
index bfbc72f..565351d 100644
--- a/keystore/Android.bp
+++ b/keystore/Android.bp
@@ -49,6 +49,7 @@
         "libhidlbase",
         "libhidltransport",
         "libhwbinder",
+        "libkeymaster4support",
         "libkeymaster_messages",
         "libkeymaster_portable",
         "libkeystore_aidl",
@@ -110,6 +111,7 @@
         "libchrome",
         "libhidlbase",
         "libhwbinder",
+        "libkeymaster4support",
         "libkeystore_binder",
     ],
 
@@ -135,6 +137,7 @@
         "libhardware",
         "libhidlbase",
         "libhwbinder",
+        "libkeymaster4support",
         "liblog",
         "libprotobuf-cpp-lite",
         "libutils",
@@ -144,6 +147,7 @@
         "libbinder",
         "libhidlbase",
         "libhwbinder",
+        "libkeymaster4support",
     ],
 }
 // Library for keystore clients
@@ -152,21 +156,20 @@
     defaults: ["keystore_defaults"],
 
     srcs: [
-        "authorization_set.cpp",
         "keyblob_utils.cpp",
         "keystore_client.proto",
         "keystore_client_impl.cpp",
         "keystore_get.cpp",
-        "keystore_tags_utils.cpp",
     ],
     shared_libs: [
-        "android.hardware.keymaster@3.0",
+        "android.hardware.keymaster@4.0",
         "libbinder",
         "libhidlbase",
         "libhwbinder",
-        "liblog",
+        "libkeymaster4support",
         "libkeystore_aidl",
         "libkeystore_parcelables",
+        "liblog",
         "libprotobuf-cpp-lite",
         "libutils",
     ],
@@ -181,7 +184,7 @@
     },
     export_include_dirs: ["include"],
     export_shared_lib_headers: [
-        "android.hardware.keymaster@3.0",
+        "android.hardware.keymaster@4.0",
         "libbinder",
         "libhidlbase",
         "libhwbinder",
@@ -217,19 +220,21 @@
 
     srcs: [
         "auth_token_table.cpp",
-        "authorization_set.cpp",
     ],
+    cflags: [ "-O0", ],
     static_libs: ["libgtest_main"],
     shared_libs: [
         "android.hardware.keymaster@4.0",
         "libhidlbase",
         "libhwbinder",
+        "libkeymaster4support",
         "libutils",
     ],
     export_shared_lib_headers: [
         "android.hardware.keymaster@4.0",
         "libhidlbase",
         "libhwbinder",
+        "libkeymaster4support",
     ],
 
     export_include_dirs: ["include"],
diff --git a/keystore/KeyStore.h b/keystore/KeyStore.h
index 60cf56d..463ed8e 100644
--- a/keystore/KeyStore.h
+++ b/keystore/KeyStore.h
@@ -21,10 +21,11 @@
 
 #include <utils/Vector.h>
 
+#include <keystore/keymaster_types.h>
+
 #include "Keymaster.h"
 #include "blob.h"
 #include "grant_store.h"
-#include "include/keystore/keymaster_tags.h"
 #include "user_state.h"
 
 namespace keystore {
diff --git a/keystore/Keymaster.h b/keystore/Keymaster.h
index 7fc2e99..cbd4eb6 100644
--- a/keystore/Keymaster.h
+++ b/keystore/Keymaster.h
@@ -18,7 +18,6 @@
 #ifndef SYSTEM_SECURITY_KEYSTORE_KEYMASTER__H_
 #define SYSTEM_SECURITY_KEYSTORE_KEYMASTER__H_
 
-#include <keystore/keymaster_tags.h>
 #include <keystore/keymaster_types.h>
 
 namespace keystore {
diff --git a/keystore/OperationResult.cpp b/keystore/OperationResult.cpp
index 62c957e..53c8d62 100644
--- a/keystore/OperationResult.cpp
+++ b/keystore/OperationResult.cpp
@@ -17,11 +17,13 @@
 
 #include "include/keystore/OperationResult.h"
 
-#include <binder/Parcel.h>
 #include <utility>
 
+#include <binder/Parcel.h>
+
+#include <keystore/keymaster_types.h>
+
 #include "keystore_aidl_hidl_marshalling_utils.h"
-#include <keystore/keymaster_tags.h>
 
 namespace android {
 namespace security {
diff --git a/keystore/auth_token_table.h b/keystore/auth_token_table.h
index 0a23c99..db60003 100644
--- a/keystore/auth_token_table.h
+++ b/keystore/auth_token_table.h
@@ -17,7 +17,6 @@
 #include <memory>
 #include <vector>
 
-#include <keystore/authorization_set.h>
 #include <keystore/keymaster_types.h>
 
 #ifndef KEYSTORE_AUTH_TOKEN_TABLE_H_
@@ -59,7 +58,7 @@
     };
 
     /**
-     * Add an authorization token to the table.  The table takes ownership of the argument.
+     * Add an authorization token to the table.
      */
     void AddAuthenticationToken(HardwareAuthToken&& auth_token);
 
diff --git a/keystore/authorization_set.cpp b/keystore/authorization_set.cpp
index e30b32d..537fe3d 100644
--- a/keystore/authorization_set.cpp
+++ b/keystore/authorization_set.cpp
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include <keystore/authorization_set.h>
+#include <keystore/keymaster_types.h>
 
 #include <assert.h>
 #include <stddef.h>
diff --git a/keystore/include/keystore/KeymasterArguments.h b/keystore/include/keystore/KeymasterArguments.h
index 329579a..99074f8 100644
--- a/keystore/include/keystore/KeymasterArguments.h
+++ b/keystore/include/keystore/KeymasterArguments.h
@@ -17,7 +17,7 @@
 
 #include <binder/Parcelable.h>
 
-#include "keymaster_tags.h"
+#include <keystore/keymaster_types.h>
 
 namespace android {
 namespace security {
diff --git a/keystore/include/keystore/OperationResult.h b/keystore/include/keystore/OperationResult.h
index 6dd5aef..2ceda9a 100644
--- a/keystore/include/keystore/OperationResult.h
+++ b/keystore/include/keystore/OperationResult.h
@@ -18,7 +18,7 @@
 #include <binder/Parcel.h>
 #include <binder/Parcelable.h>
 
-#include "keymaster_tags.h"
+#include "keymaster_types.h"
 #include "keystore_return_types.h"
 
 namespace android {
diff --git a/keystore/include/keystore/authorization_set.h b/keystore/include/keystore/authorization_set.h
deleted file mode 100644
index 0e57a19..0000000
--- a/keystore/include/keystore/authorization_set.h
+++ /dev/null
@@ -1,336 +0,0 @@
-/*
- * Copyright 2014 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.
- */
-
-#ifndef SYSTEM_SECURITY_KEYSTORE_AUTHORIZATION_SET_H_
-#define SYSTEM_SECURITY_KEYSTORE_AUTHORIZATION_SET_H_
-
-#include "keymaster_tags.h"
-#include <vector>
-
-namespace keystore {
-
-class AuthorizationSetBuilder;
-
-/**
- * An ordered collection of KeyParameters. It provides memory ownership and some convenient
- * functionality for sorting, deduplicating, joining, and subtracting sets of KeyParameters.
- * For serialization, wrap the backing store of this structure in a hidl_vec<KeyParameter>.
- */
-class AuthorizationSet {
-  public:
-    /**
-     * Construct an empty, dynamically-allocated, growable AuthorizationSet.
-     */
-    AuthorizationSet() {};
-
-    // Copy constructor.
-    AuthorizationSet(const AuthorizationSet& other) : data_(other.data_) {}
-
-    // Move constructor.
-    AuthorizationSet(AuthorizationSet&& other) : data_(std::move(other.data_)) {}
-
-    // Constructor from hidl_vec<KeyParameter>
-    AuthorizationSet(const hidl_vec<KeyParameter>& other) {
-        *this = other;
-    }
-
-    // Copy assignment.
-    AuthorizationSet& operator=(const AuthorizationSet& other) {
-        data_ = other.data_;
-        return *this;
-    }
-
-    // Move assignment.
-    AuthorizationSet& operator=(AuthorizationSet&& other) {
-        data_ = std::move(other.data_);
-        return *this;
-    }
-
-    AuthorizationSet& operator=(const hidl_vec<KeyParameter>& other) {
-        if (other.size() > 0) {
-            data_.resize(other.size());
-            for (size_t i = 0; i < data_.size(); ++i) {
-                /* This makes a deep copy even of embedded blobs.
-                 * See assignment operator/copy constructor of hidl_vec.*/
-                data_[i] = other[i];
-            }
-        }
-        return *this;
-    }
-
-    /**
-     * Clear existing authorization set data
-     */
-    void Clear();
-
-    ~AuthorizationSet() = default;
-
-    /**
-     * Returns the size of the set.
-     */
-    size_t size() const { return data_.size(); }
-
-    /**
-     * Returns true if the set is empty.
-     */
-    bool empty() const { return size() == 0; }
-
-    /**
-     * Returns the data in the set, directly. Be careful with this.
-     */
-    const KeyParameter* data() const { return data_.data(); }
-
-    /**
-     * Sorts the set
-     */
-    void Sort();
-
-    /**
-     * Sorts the set and removes duplicates (inadvertently duplicating tags is easy to do with the
-     * AuthorizationSetBuilder).
-     */
-    void Deduplicate();
-
-    /**
-     * Adds all elements from \p set that are not already present in this AuthorizationSet.  As a
-     * side-effect, if \p set is not null this AuthorizationSet will end up sorted.
-     */
-    void Union(const AuthorizationSet& set);
-
-    /**
-     * Removes all elements in \p set from this AuthorizationSet.
-     */
-    void Subtract(const AuthorizationSet& set);
-
-    /**
-     * Returns the offset of the next entry that matches \p tag, starting from the element after \p
-     * begin.  If not found, returns -1.
-     */
-    int find(Tag tag, int begin = -1) const;
-
-    /**
-     * Removes the entry at the specified index. Returns true if successful, false if the index was
-     * out of bounds.
-     */
-    bool erase(int index);
-
-    /**
-     * Returns iterator (pointer) to beginning of elems array, to enable STL-style iteration
-     */
-    std::vector<KeyParameter>::const_iterator begin() const { return data_.begin(); }
-
-    /**
-     * Returns iterator (pointer) one past end of elems array, to enable STL-style iteration
-     */
-    std::vector<KeyParameter>::const_iterator end() const { return data_.end(); }
-
-    /**
-     * Returns the nth element of the set.
-     * Like for std::vector::operator[] there is no range check performed. Use of out of range
-     * indices is undefined.
-     */
-    KeyParameter& operator[](int n);
-
-    /**
-     * Returns the nth element of the set.
-     * Like for std::vector::operator[] there is no range check performed. Use of out of range
-     * indices is undefined.
-     */
-    const KeyParameter& operator[](int n) const;
-
-    /**
-     * Returns true if the set contains at least one instance of \p tag
-     */
-    bool Contains(Tag tag) const {
-        return find(tag) != -1;
-    }
-
-    template <TagType tag_type, Tag tag, typename ValueT>
-    bool Contains(TypedTag<tag_type, tag> ttag, const ValueT& value) const {
-        for (const auto& param: data_) {
-            auto entry = authorizationValue(ttag, param);
-            if (entry.isOk() && entry.value() == value) return true;
-        }
-        return false;
-    }
-    /**
-     * Returns the number of \p tag entries.
-     */
-    size_t GetTagCount(Tag tag) const;
-
-    template <typename T>
-    inline NullOr<const typename TypedTag2ValueType<T>::type&> GetTagValue(T tag) const {
-        auto entry = GetEntry(tag);
-        if (entry.isOk()) return authorizationValue(tag, entry.value());
-        return {};
-    }
-
-    void push_back(const KeyParameter& param) {
-        data_.push_back(param);
-    }
-    void push_back(KeyParameter&& param) {
-        data_.push_back(std::move(param));
-    }
-
-    /**
-     * Append the tag and enumerated value to the set.
-     * "val" may be exactly one parameter unless a boolean parameter is added.
-     * In this case "val" is omitted. This condition is checked at compile time by Authorization()
-     */
-    template <typename TypedTagT, typename... Value>
-    void push_back(TypedTagT tag, Value&&... val) {
-        push_back(Authorization(tag, std::forward<Value>(val)...));
-    }
-
-    template <typename Iterator>
-    void append(Iterator begin, Iterator end) {
-        while (begin != end) {
-            push_back(*begin);
-            ++begin;
-        }
-    }
-
-    hidl_vec<KeyParameter> hidl_data() const {
-        hidl_vec<KeyParameter> result;
-        result.setToExternal(const_cast<KeyParameter*>(data()), size());
-        return result;
-    }
-
-    void Serialize(std::ostream* out) const;
-    void Deserialize(std::istream* in);
-
-  private:
-    NullOr<const KeyParameter&> GetEntry(Tag tag) const;
-
-    std::vector<KeyParameter> data_;
-};
-
-class AuthorizationSetBuilder: public AuthorizationSet {
-  public:
-    template <typename TagType, typename... ValueType>
-    AuthorizationSetBuilder& Authorization(TagType ttag, ValueType&&... value) {
-        push_back(ttag, std::forward<ValueType>(value)...);
-        return *this;
-    }
-
-    template <Tag tag>
-    AuthorizationSetBuilder& Authorization(TypedTag<TagType::BYTES, tag> ttag, const uint8_t* data,
-                                           size_t data_length) {
-        hidl_vec<uint8_t> new_blob;
-        new_blob.setToExternal(const_cast<uint8_t*>(data), data_length);
-        push_back(ttag, std::move(new_blob));
-        return *this;
-    }
-
-    template <Tag tag>
-    AuthorizationSetBuilder& Authorization(TypedTag<TagType::BYTES, tag> ttag, const char* data,
-                                           size_t data_length) {
-        return Authorization(ttag, reinterpret_cast<const uint8_t*>(data), data_length);
-    }
-
-    AuthorizationSetBuilder& RsaKey(uint32_t key_size, uint64_t public_exponent);
-    AuthorizationSetBuilder& EcdsaKey(uint32_t key_size);
-    AuthorizationSetBuilder& AesKey(uint32_t key_size);
-    AuthorizationSetBuilder& HmacKey(uint32_t key_size);
-
-    AuthorizationSetBuilder& RsaSigningKey(uint32_t key_size, uint64_t public_exponent);
-    AuthorizationSetBuilder& RsaEncryptionKey(uint32_t key_size, uint64_t public_exponent);
-    AuthorizationSetBuilder& EcdsaSigningKey(uint32_t key_size);
-    AuthorizationSetBuilder& AesEncryptionKey(uint32_t key_size);
-
-    AuthorizationSetBuilder& SigningKey();
-    AuthorizationSetBuilder& EncryptionKey();
-    AuthorizationSetBuilder& NoDigestOrPadding();
-    AuthorizationSetBuilder& EcbMode();
-
-    AuthorizationSetBuilder& Digest(Digest digest) {
-        return Authorization(TAG_DIGEST, digest);
-    }
-
-    AuthorizationSetBuilder& Padding(PaddingMode padding) {
-        return Authorization(TAG_PADDING, padding);
-    }
-};
-
-inline AuthorizationSetBuilder& AuthorizationSetBuilder::RsaKey(uint32_t key_size,
-                                                                uint64_t public_exponent) {
-    Authorization(TAG_ALGORITHM, Algorithm::RSA);
-    Authorization(TAG_KEY_SIZE, key_size);
-    Authorization(TAG_RSA_PUBLIC_EXPONENT, public_exponent);
-    return *this;
-}
-
-inline AuthorizationSetBuilder& AuthorizationSetBuilder::EcdsaKey(uint32_t key_size) {
-    Authorization(TAG_ALGORITHM, Algorithm::EC);
-    Authorization(TAG_KEY_SIZE, key_size);
-    return *this;
-}
-
-inline AuthorizationSetBuilder& AuthorizationSetBuilder::AesKey(uint32_t key_size) {
-    Authorization(TAG_ALGORITHM, Algorithm::AES);
-    return Authorization(TAG_KEY_SIZE, key_size);
-}
-
-inline AuthorizationSetBuilder& AuthorizationSetBuilder::HmacKey(uint32_t key_size) {
-    Authorization(TAG_ALGORITHM, Algorithm::HMAC);
-    Authorization(TAG_KEY_SIZE, key_size);
-    return SigningKey();
-}
-
-inline AuthorizationSetBuilder& AuthorizationSetBuilder::RsaSigningKey(uint32_t key_size,
-                                                                       uint64_t public_exponent) {
-    RsaKey(key_size, public_exponent);
-    return SigningKey();
-}
-
-inline AuthorizationSetBuilder&
-AuthorizationSetBuilder::RsaEncryptionKey(uint32_t key_size, uint64_t public_exponent) {
-    RsaKey(key_size, public_exponent);
-    return EncryptionKey();
-}
-
-inline AuthorizationSetBuilder& AuthorizationSetBuilder::EcdsaSigningKey(uint32_t key_size) {
-    EcdsaKey(key_size);
-    return SigningKey();
-}
-
-inline AuthorizationSetBuilder& AuthorizationSetBuilder::AesEncryptionKey(uint32_t key_size) {
-    AesKey(key_size);
-    return EncryptionKey();
-}
-
-inline AuthorizationSetBuilder& AuthorizationSetBuilder::SigningKey() {
-    Authorization(TAG_PURPOSE, KeyPurpose::SIGN);
-    return Authorization(TAG_PURPOSE, KeyPurpose::VERIFY);
-}
-
-inline AuthorizationSetBuilder& AuthorizationSetBuilder::EncryptionKey() {
-    Authorization(TAG_PURPOSE, KeyPurpose::ENCRYPT);
-    return Authorization(TAG_PURPOSE, KeyPurpose::DECRYPT);
-}
-
-inline AuthorizationSetBuilder& AuthorizationSetBuilder::NoDigestOrPadding() {
-    Authorization(TAG_DIGEST, Digest::NONE);
-    return Authorization(TAG_PADDING, PaddingMode::NONE);
-}
-
-inline AuthorizationSetBuilder& AuthorizationSetBuilder::EcbMode() {
-    return Authorization(TAG_BLOCK_MODE, BlockMode::ECB);
-}
-
-}  // namespace keystore
-
-#endif  // SYSTEM_SECURITY_KEYSTORE_AUTHORIZATION_SET_H_
diff --git a/keystore/include/keystore/keymaster_tags.h b/keystore/include/keystore/keymaster_tags.h
deleted file mode 100644
index 6d2048a..0000000
--- a/keystore/include/keystore/keymaster_tags.h
+++ /dev/null
@@ -1,352 +0,0 @@
-/*
- * Copyright 2014 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.
- */
-
-#ifndef SYSTEM_SECURITY_KEYSTORE_KEYMASTER_TAGS_H_
-#define SYSTEM_SECURITY_KEYSTORE_KEYMASTER_TAGS_H_
-
-/**
- * This header contains various definitions that make working with keymaster tags safer and easier.
- *
- * It makes use of a fair amount of template metaprogramming. The metaprogramming serves the purpose
- * of making it impossible to make certain classes of mistakes when operating on keymaster
- * authorizations.  For example, it's an error to create a KeyParameter with tag == Tag::PURPOSE
- * and then to assign Algorithm::RSA to algorithm element of its union. But because the user
- * must choose the union field, there could be a mismatch which the compiler has now way to
- * diagnose.
- *
- * The machinery in this header solves these problems by describing which union field corresponds
- * to which Tag. Central to this mechanism is the template TypedTag. It has zero size and binds a
- * numeric Tag to a type that the compiler understands. By means of the macro DECLARE_TYPED_TAG,
- * we declare types for each of the tags defined in hardware/interfaces/keymaster/2.0/types.hal.
- *
- * The macro DECLARE_TYPED_TAG(name) generates a typename TAG_name_t and a zero sized instance
- * TAG_name. Once these typed tags have been declared we define metafunctions mapping the each tag
- * to its value c++ type and the correct union element of KeyParameter. This is done by means of
- * the macros MAKE_TAG_*VALUE_ACCESSOR, which generates TypedTag2ValueType, a metafunction mapping
- * a typed tag to the corresponding c++ type, and access function, accessTagValue returning a
- * reference to the correct element of KeyParameter.
- * E.g.:
- *      given "KeyParameter param;" then "accessTagValue(TAG_PURPOSE, param)"
- *      yields a reference to param.f.purpose
- * If used in an assignment the compiler can now check the compatibility of the assigned value.
- *
- * For convenience we also provide the constructor like function Authorization().
- * Authorization takes a typed tag and a value and checks at compile time whether the value given
- * is suitable for the given tag. At runtime it creates a new KeyParameter initialized with the
- * given tag and value and returns it by value.
- *
- * The second convenience function, authorizationValue, allows access to the KeyParameter value in
- * a safe way. It takes a typed tag and a KeyParameter and returns a reference to the value wrapped
- * by NullOr. NullOr has out-of-band information about whether it is save to access the wrapped
- * reference.
- * E.g.:
- *      auto param = Authorization(TAG_ALGORITM, Algorithm::RSA);
- *      auto value1 = authorizationValue(TAG_PURPOSE, param);
- *      auto value2 = authorizationValue(TAG_ALGORITM, param);
- * value1.isOk() yields false, but value2.isOk() yields true, thus value2.value() is save to access.
- */
-
-#include <android/hardware/keymaster/3.0/IHwKeymasterDevice.h>
-#include <type_traits>
-
-#include "keymaster_types.h"
-
-namespace keystore {
-
-// This namespace alias is temporary.  This file will be removed in favor of the KM4 support
-// library version.
-namespace oldkeymaster = android::hardware::keymaster::V3_0;
-
-using keymaster::ErrorCode;
-using keymaster::HardwareAuthToken;
-using keymaster::HmacSharingParameters;
-using keymaster::IKeymasterDevice;
-using keymaster::KeyCharacteristics;
-using keymaster::KeyOrigin;
-using keymaster::KeyParameter;
-using keymaster::KeyPurpose;
-using keymaster::OperationHandle;
-using keymaster::SecurityLevel;
-using keymaster::Tag;
-using keymaster::VerificationToken;
-using oldkeymaster::Algorithm;
-using oldkeymaster::BlockMode;
-using oldkeymaster::Digest;
-using oldkeymaster::EcCurve;
-using oldkeymaster::HardwareAuthenticatorType;
-using oldkeymaster::KeyBlobUsageRequirements;
-using oldkeymaster::KeyDerivationFunction;
-using oldkeymaster::KeyFormat;
-using oldkeymaster::PaddingMode;
-using oldkeymaster::TagType;
-
-using ::android::hardware::hidl_vec;
-using ::android::hardware::Return;
-
-// The following create the numeric values that KM_TAG_PADDING and KM_TAG_DIGEST used to have.  We
-// need these old values to be able to support old keys that use them.
-static const int32_t KM_TAG_DIGEST_OLD = static_cast<int32_t>(TagType::ENUM) | 5;
-static const int32_t KM_TAG_PADDING_OLD = static_cast<int32_t>(TagType::ENUM) | 7;
-
-constexpr TagType typeFromTag(Tag tag) {
-    return static_cast<TagType>(static_cast<uint32_t>(tag) & static_cast<uint32_t>(0xf0000000));
-}
-
-/**
- * TypedTag is a templatized version of Tag, which provides compile-time checking of
- * keymaster tag types. Instances are convertible to Tag, so they can be used wherever
- * Tag is expected, and because they encode the tag type it's possible to create
- * function overloads that only operate on tags with a particular type.
- */
-template <TagType tag_type, Tag tag> struct TypedTag {
-    inline TypedTag() {
-        // Ensure that it's impossible to create a TypedTag instance whose 'tag' doesn't have type
-        // 'tag_type'.  Attempting to instantiate a tag with the wrong type will result in a compile
-        // error (no match for template specialization StaticAssert<false>), with no run-time cost.
-        static_assert(typeFromTag(tag) == tag_type, "mismatch between tag and tag_type");
-    }
-    operator Tag() const { return tag; }
-};
-
-template <Tag tag> struct Tag2TypedTag { typedef TypedTag<typeFromTag(tag), tag> type; };
-
-template <Tag tag> struct Tag2String;
-
-#define _TAGS_STRINGIFY(x) #x
-#define TAGS_STRINGIFY(x) _TAGS_STRINGIFY(x)
-
-#define DECLARE_TYPED_TAG(name)                                                                    \
-    typedef typename Tag2TypedTag<Tag::name>::type TAG_##name##_t;                                 \
-    extern TAG_##name##_t TAG_##name;                                                              \
-    template <> struct Tag2String<Tag::name> {                                                     \
-        static const char* value() { return "Tag::" TAGS_STRINGIFY(name); }                        \
-    }
-
-DECLARE_TYPED_TAG(INVALID);
-DECLARE_TYPED_TAG(KEY_SIZE);
-DECLARE_TYPED_TAG(MAC_LENGTH);
-DECLARE_TYPED_TAG(CALLER_NONCE);
-DECLARE_TYPED_TAG(MIN_MAC_LENGTH);
-DECLARE_TYPED_TAG(RSA_PUBLIC_EXPONENT);
-DECLARE_TYPED_TAG(INCLUDE_UNIQUE_ID);
-DECLARE_TYPED_TAG(ACTIVE_DATETIME);
-DECLARE_TYPED_TAG(ORIGINATION_EXPIRE_DATETIME);
-DECLARE_TYPED_TAG(USAGE_EXPIRE_DATETIME);
-DECLARE_TYPED_TAG(MIN_SECONDS_BETWEEN_OPS);
-DECLARE_TYPED_TAG(MAX_USES_PER_BOOT);
-DECLARE_TYPED_TAG(USER_SECURE_ID);
-DECLARE_TYPED_TAG(NO_AUTH_REQUIRED);
-DECLARE_TYPED_TAG(AUTH_TIMEOUT);
-DECLARE_TYPED_TAG(ALLOW_WHILE_ON_BODY);
-DECLARE_TYPED_TAG(APPLICATION_ID);
-DECLARE_TYPED_TAG(APPLICATION_DATA);
-DECLARE_TYPED_TAG(CREATION_DATETIME);
-DECLARE_TYPED_TAG(ROLLBACK_RESISTANCE);
-DECLARE_TYPED_TAG(ROOT_OF_TRUST);
-DECLARE_TYPED_TAG(ASSOCIATED_DATA);
-DECLARE_TYPED_TAG(NONCE);
-DECLARE_TYPED_TAG(BOOTLOADER_ONLY);
-DECLARE_TYPED_TAG(OS_VERSION);
-DECLARE_TYPED_TAG(OS_PATCHLEVEL);
-DECLARE_TYPED_TAG(UNIQUE_ID);
-DECLARE_TYPED_TAG(ATTESTATION_CHALLENGE);
-DECLARE_TYPED_TAG(ATTESTATION_APPLICATION_ID);
-DECLARE_TYPED_TAG(RESET_SINCE_ID_ROTATION);
-
-DECLARE_TYPED_TAG(PURPOSE);
-DECLARE_TYPED_TAG(ALGORITHM);
-DECLARE_TYPED_TAG(BLOCK_MODE);
-DECLARE_TYPED_TAG(DIGEST);
-DECLARE_TYPED_TAG(PADDING);
-DECLARE_TYPED_TAG(BLOB_USAGE_REQUIREMENTS);
-DECLARE_TYPED_TAG(ORIGIN);
-DECLARE_TYPED_TAG(USER_AUTH_TYPE);
-DECLARE_TYPED_TAG(EC_CURVE);
-
-template <typename... Elems> struct MetaList {};
-
-using all_tags_t = MetaList<
-    TAG_INVALID_t, TAG_KEY_SIZE_t, TAG_MAC_LENGTH_t, TAG_CALLER_NONCE_t, TAG_MIN_MAC_LENGTH_t,
-    TAG_RSA_PUBLIC_EXPONENT_t, TAG_INCLUDE_UNIQUE_ID_t, TAG_ACTIVE_DATETIME_t,
-    TAG_ORIGINATION_EXPIRE_DATETIME_t, TAG_USAGE_EXPIRE_DATETIME_t, TAG_MIN_SECONDS_BETWEEN_OPS_t,
-    TAG_MAX_USES_PER_BOOT_t, TAG_USER_SECURE_ID_t, TAG_NO_AUTH_REQUIRED_t, TAG_AUTH_TIMEOUT_t,
-    TAG_ALLOW_WHILE_ON_BODY_t, TAG_APPLICATION_ID_t, TAG_APPLICATION_DATA_t,
-    TAG_CREATION_DATETIME_t, TAG_ROLLBACK_RESISTANCE_t, TAG_ROOT_OF_TRUST_t, TAG_ASSOCIATED_DATA_t,
-    TAG_NONCE_t, TAG_BOOTLOADER_ONLY_t, TAG_OS_VERSION_t, TAG_OS_PATCHLEVEL_t, TAG_UNIQUE_ID_t,
-    TAG_ATTESTATION_CHALLENGE_t, TAG_ATTESTATION_APPLICATION_ID_t, TAG_RESET_SINCE_ID_ROTATION_t,
-    TAG_PURPOSE_t, TAG_ALGORITHM_t, TAG_BLOCK_MODE_t, TAG_DIGEST_t, TAG_PADDING_t,
-    TAG_BLOB_USAGE_REQUIREMENTS_t, TAG_ORIGIN_t, TAG_USER_AUTH_TYPE_t, TAG_EC_CURVE_t>;
-
-/* implementation in keystore_utils.cpp */
-extern const char* stringifyTag(Tag tag);
-
-template <typename TypedTagType> struct TypedTag2ValueType;
-
-#define MAKE_TAG_VALUE_ACCESSOR(tag_type, field_name)                                              \
-    template <Tag tag> struct TypedTag2ValueType<TypedTag<tag_type, tag>> {                        \
-        typedef decltype(static_cast<KeyParameter*>(nullptr)->field_name) type;                    \
-    };                                                                                             \
-    template <Tag tag>                                                                             \
-    inline auto accessTagValue(TypedTag<tag_type, tag>, const KeyParameter& param)                 \
-        ->const decltype(param.field_name)& {                                                      \
-        return param.field_name;                                                                   \
-    }                                                                                              \
-    template <Tag tag>                                                                             \
-    inline auto accessTagValue(TypedTag<tag_type, tag>, KeyParameter& param)                       \
-        ->decltype(param.field_name)& {                                                            \
-        return param.field_name;                                                                   \
-    }
-
-MAKE_TAG_VALUE_ACCESSOR(TagType::ULONG, f.longInteger)
-MAKE_TAG_VALUE_ACCESSOR(TagType::ULONG_REP, f.longInteger)
-MAKE_TAG_VALUE_ACCESSOR(TagType::DATE, f.dateTime)
-MAKE_TAG_VALUE_ACCESSOR(TagType::UINT, f.integer)
-MAKE_TAG_VALUE_ACCESSOR(TagType::UINT_REP, f.integer)
-MAKE_TAG_VALUE_ACCESSOR(TagType::BOOL, f.boolValue)
-MAKE_TAG_VALUE_ACCESSOR(TagType::BYTES, blob)
-MAKE_TAG_VALUE_ACCESSOR(TagType::BIGNUM, blob)
-
-#define MAKE_TAG_ENUM_VALUE_ACCESSOR(typed_tag, field_name)                                        \
-    template <> struct TypedTag2ValueType<decltype(typed_tag)> {                                   \
-        typedef decltype(static_cast<KeyParameter*>(nullptr)->field_name) type;                    \
-    };                                                                                             \
-    inline auto accessTagValue(decltype(typed_tag), const KeyParameter& param)                     \
-        ->const decltype(param.field_name)& {                                                      \
-        return param.field_name;                                                                   \
-    }                                                                                              \
-    inline auto accessTagValue(decltype(typed_tag), KeyParameter& param)                           \
-        ->decltype(param.field_name)& {                                                            \
-        return param.field_name;                                                                   \
-    }
-
-MAKE_TAG_ENUM_VALUE_ACCESSOR(TAG_ALGORITHM, f.algorithm)
-MAKE_TAG_ENUM_VALUE_ACCESSOR(TAG_BLOB_USAGE_REQUIREMENTS, f.keyBlobUsageRequirements)
-MAKE_TAG_ENUM_VALUE_ACCESSOR(TAG_BLOCK_MODE, f.blockMode)
-MAKE_TAG_ENUM_VALUE_ACCESSOR(TAG_DIGEST, f.digest)
-MAKE_TAG_ENUM_VALUE_ACCESSOR(TAG_EC_CURVE, f.ecCurve)
-MAKE_TAG_ENUM_VALUE_ACCESSOR(TAG_ORIGIN, f.origin)
-MAKE_TAG_ENUM_VALUE_ACCESSOR(TAG_PADDING, f.paddingMode)
-MAKE_TAG_ENUM_VALUE_ACCESSOR(TAG_PURPOSE, f.purpose)
-MAKE_TAG_ENUM_VALUE_ACCESSOR(TAG_USER_AUTH_TYPE, f.hardwareAuthenticatorType)
-
-template <TagType tag_type, Tag tag, typename ValueT>
-inline KeyParameter makeKeyParameter(TypedTag<tag_type, tag> ttag, ValueT&& value) {
-    KeyParameter param;
-    param.tag = tag;
-    param.f.longInteger = 0;
-    accessTagValue(ttag, param) = std::forward<ValueT>(value);
-    return param;
-}
-
-// the boolean case
-template <Tag tag> inline KeyParameter makeKeyParameter(TypedTag<TagType::BOOL, tag>) {
-    KeyParameter param;
-    param.tag = tag;
-    param.f.boolValue = true;
-    return param;
-}
-
-template <typename... Pack> struct FirstOrNoneHelper;
-template <typename First> struct FirstOrNoneHelper<First> { typedef First type; };
-template <> struct FirstOrNoneHelper<> {
-    struct type {};
-};
-
-template <typename... Pack> using FirstOrNone = typename FirstOrNoneHelper<Pack...>::type;
-
-template <TagType tag_type, Tag tag, typename... Args>
-inline KeyParameter Authorization(TypedTag<tag_type, tag> ttag, Args&&... args) {
-    static_assert(tag_type != TagType::BOOL || (sizeof...(args) == 0),
-                  "TagType::BOOL Authorizations do not take parameters. Presence is truth.");
-    static_assert(tag_type == TagType::BOOL || (sizeof...(args) == 1),
-                  "Authorization other then TagType::BOOL take exactly one parameter.");
-    static_assert(
-        tag_type == TagType::BOOL ||
-            std::is_convertible<std::remove_cv_t<std::remove_reference_t<FirstOrNone<Args...>>>,
-                                typename TypedTag2ValueType<TypedTag<tag_type, tag>>::type>::value,
-        "Invalid argument type for given tag.");
-
-    return makeKeyParameter(ttag, std::forward<Args>(args)...);
-}
-
-/**
- * This class wraps a (mostly return) value and stores whether or not the wrapped value is valid out
- * of band. Note that if the wrapped value is a reference it is unsafe to access the value if
- * !isOk(). If the wrapped type is a pointer or value and !isOk(), it is still safe to access the
- * wrapped value. In this case the pointer will be NULL though, and the value will be default
- * constructed.
- */
-template <typename ValueT> class NullOr {
-    template <typename T> struct reference_initializer {
-        static T&& init() { return *static_cast<std::remove_reference_t<T>*>(nullptr); }
-    };
-    template <typename T> struct pointer_initializer {
-        static T init() { return nullptr; }
-    };
-    template <typename T> struct value_initializer {
-        static T init() { return T(); }
-    };
-    template <typename T>
-    using initializer_t =
-        std::conditional_t<std::is_lvalue_reference<T>::value, reference_initializer<T>,
-                           std::conditional_t<std::is_pointer<T>::value, pointer_initializer<T>,
-                                              value_initializer<T>>>;
-
-  public:
-    NullOr() : value_(initializer_t<ValueT>::init()), null_(true) {}
-    NullOr(ValueT&& value) : value_(std::forward<ValueT>(value)), null_(false) {}
-
-    bool isOk() const { return !null_; }
-
-    const ValueT& value() const & { return value_; }
-    ValueT& value() & { return value_; }
-    ValueT&& value() && { return std::move(value_); }
-
-  private:
-    ValueT value_;
-    bool null_;
-};
-
-template <typename T> std::remove_reference_t<T> NullOrOr(T&& v) {
-    if (v.isOk()) return v;
-    return {};
-}
-
-template <typename Head, typename... Tail>
-std::remove_reference_t<Head> NullOrOr(Head&& head, Tail&&... tail) {
-    if (head.isOk()) return head;
-    return NullOrOr(std::forward<Tail>(tail)...);
-}
-
-template <typename Default, typename Wrapped>
-std::remove_reference_t<Wrapped> defaultOr(NullOr<Wrapped>&& optional, Default&& def) {
-    static_assert(std::is_convertible<std::remove_reference_t<Default>,
-                                      std::remove_reference_t<Wrapped>>::value,
-                  "Type of default value must match the type wrapped by NullOr");
-    if (optional.isOk()) return optional.value();
-    return def;
-}
-
-template <TagType tag_type, Tag tag>
-inline NullOr<const typename TypedTag2ValueType<TypedTag<tag_type, tag>>::type&>
-authorizationValue(TypedTag<tag_type, tag> ttag, const KeyParameter& param) {
-    if (tag != param.tag) return {};
-    return accessTagValue(ttag, param);
-}
-
-}  // namespace keystore
-
-#endif  // SYSTEM_SECURITY_KEYSTORE_KEYMASTER_TAGS_H_
diff --git a/keystore/include/keystore/keymaster_types.h b/keystore/include/keystore/keymaster_types.h
index 272105f..d367136 100644
--- a/keystore/include/keystore/keymaster_types.h
+++ b/keystore/include/keystore/keymaster_types.h
@@ -12,22 +12,89 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#ifndef SECURITY_KEYSTORE_INCLUDE_KEYSTORE_KEYMASTER_TYPES_H_
+#define SECURITY_KEYSTORE_INCLUDE_KEYSTORE_KEYMASTER_TYPES_H_
+
 #include <android/hardware/keymaster/4.0/IKeymasterDevice.h>
 #include <android/hardware/keymaster/4.0/types.h>
 
+#include <keymasterV4_0/authorization_set.h>
+#include <keymasterV4_0/keymaster_tags.h>
+
 /**
  * This header lifts the types from the current Keymaster version into the keystore namespace.
  */
 
 namespace keystore {
 
+// Changing this namespace alias will change the keymaster version.
 namespace keymaster = ::android::hardware::keymaster::V4_0;
 
+using android::hardware::hidl_vec;
+using android::hardware::Return;
+
 using keymaster::IKeymasterDevice;
 using keymaster::SecurityLevel;
 
+using keymaster::AuthorizationSet;
+using keymaster::AuthorizationSetBuilder;
+
+using keymaster::Algorithm;
+using keymaster::BlockMode;
+using keymaster::Digest;
+using keymaster::EcCurve;
+using keymaster::ErrorCode;
+using keymaster::HardwareAuthenticatorType;
+using keymaster::HardwareAuthToken;
+using keymaster::HmacSharingParameters;
+using keymaster::KeyCharacteristics;
+using keymaster::KeyFormat;
+using keymaster::KeyParameter;
+using keymaster::KeyPurpose;
+using keymaster::OperationHandle;
+using keymaster::PaddingMode;
+using keymaster::SecurityLevel;
+using keymaster::Tag;
+using keymaster::TagType;
+using keymaster::VerificationToken;
+
+using keymaster::TAG_ACTIVE_DATETIME;
+using keymaster::TAG_ALGORITHM;
+using keymaster::TAG_ALLOW_WHILE_ON_BODY;
+using keymaster::TAG_APPLICATION_DATA;
+using keymaster::TAG_APPLICATION_ID;
+using keymaster::TAG_ATTESTATION_APPLICATION_ID;
+using keymaster::TAG_AUTH_TIMEOUT;
+using keymaster::TAG_BLOCK_MODE;
+using keymaster::TAG_DIGEST;
+using keymaster::TAG_EC_CURVE;
+using keymaster::TAG_KEY_SIZE;
+using keymaster::TAG_MAC_LENGTH;
+using keymaster::TAG_MAX_USES_PER_BOOT;
+using keymaster::TAG_MIN_MAC_LENGTH;
+using keymaster::TAG_MIN_SECONDS_BETWEEN_OPS;
+using keymaster::TAG_NO_AUTH_REQUIRED;
+using keymaster::TAG_NONCE;
+using keymaster::TAG_ORIGINATION_EXPIRE_DATETIME;
+using keymaster::TAG_PADDING;
+using keymaster::TAG_PURPOSE;
+using keymaster::TAG_RESET_SINCE_ID_ROTATION;
+using keymaster::TAG_RSA_PUBLIC_EXPONENT;
+using keymaster::TAG_USAGE_EXPIRE_DATETIME;
+using keymaster::TAG_USER_AUTH_TYPE;
+using keymaster::TAG_USER_SECURE_ID;
+
+using keymaster::NullOr;
+
 using Km3HardwareAuthToken = ::android::hardware::keymaster::V3_0::HardwareAuthToken;
 using Km3HardwareAuthenticatorType =
     ::android::hardware::keymaster::V3_0::HardwareAuthenticatorType;
 
+// The following create the numeric values that KM_TAG_PADDING and KM_TAG_DIGEST used to have.  We
+// need these old values to be able to support old keys that use them.
+constexpr int32_t KM_TAG_DIGEST_OLD = static_cast<int32_t>(TagType::ENUM) | 5;
+constexpr int32_t KM_TAG_PADDING_OLD = static_cast<int32_t>(TagType::ENUM) | 7;
+
 }  // namespace keystore
+
+#endif  // SYSTEM_SECURITY_KEYSTORE_KM4_AUTHORIZATION_SET_H_
diff --git a/keystore/include/keystore/keystore_client.h b/keystore/include/keystore/keystore_client.h
index 928b2e6..67ebad3 100644
--- a/keystore/include/keystore/keystore_client.h
+++ b/keystore/include/keystore/keystore_client.h
@@ -21,7 +21,7 @@
 
 #include <android-base/macros.h>
 
-#include "authorization_set.h"
+#include "keymaster_types.h"
 #include "keystore.h"
 #include "keystore_return_types.h"
 
diff --git a/keystore/include/keystore/keystore_hidl_support.h b/keystore/include/keystore/keystore_hidl_support.h
index 944c3f6..7a3723e 100644
--- a/keystore/include/keystore/keystore_hidl_support.h
+++ b/keystore/include/keystore/keystore_hidl_support.h
@@ -27,7 +27,7 @@
 #include <hardware/hw_auth_token.h>
 #include <hidl/Status.h>
 
-#include <keystore/keymaster_tags.h>
+#include <keystore/keymaster_types.h>
 
 namespace keystore {
 
diff --git a/keystore/keymaster_enforcement.h b/keystore/keymaster_enforcement.h
index d751071..d7b27fc 100644
--- a/keystore/keymaster_enforcement.h
+++ b/keystore/keymaster_enforcement.h
@@ -19,7 +19,7 @@
 
 #include <stdio.h>
 
-#include <keystore/authorization_set.h>
+#include <keystore/keymaster_types.h>
 
 namespace keystore {
 
diff --git a/keystore/keystore_aidl_hidl_marshalling_utils.h b/keystore/keystore_aidl_hidl_marshalling_utils.h
index 61f1ad1..13edbd2 100644
--- a/keystore/keystore_aidl_hidl_marshalling_utils.h
+++ b/keystore/keystore_aidl_hidl_marshalling_utils.h
@@ -18,10 +18,12 @@
 #ifndef KEYSTORE_KEYSTORE_AIDL_HIDL_MARSHALLING_UTILS_H_
 #define KEYSTORE_KEYSTORE_AIDL_HIDL_MARSHALLING_UTILS_H_
 
-#include <binder/Parcel.h>
-#include <keystore/keymaster_tags.h>
 #include <utility>
 
+#include <binder/Parcel.h>
+
+#include <keystore/keymaster_types.h>
+
 namespace keystore {
 
 template <typename Fn, typename... Args>
diff --git a/keystore/keystore_cli_v2.cpp b/keystore/keystore_cli_v2.cpp
index 95fc491..9e184e8 100644
--- a/keystore/keystore_cli_v2.cpp
+++ b/keystore/keystore_cli_v2.cpp
@@ -17,16 +17,13 @@
 #include <string>
 #include <vector>
 
-#include "base/command_line.h"
-#include "base/files/file_util.h"
-#include "base/strings/string_util.h"
-#include "keystore/authorization_set.h"
-#include "keystore/keymaster_tags.h"
-#include "keystore/keystore_client_impl.h"
+#include <base/command_line.h>
+#include <base/files/file_util.h>
+#include <base/strings/string_util.h>
+#include <keystore/keymaster_types.h>
+#include <keystore/keystore_client_impl.h>
 
 using base::CommandLine;
-using keystore::AuthorizationSet;
-//using keymaster::AuthorizationSetBuilder;
 using keystore::KeystoreClient;
 
 namespace {
@@ -57,12 +54,13 @@
 
 std::unique_ptr<KeystoreClient> CreateKeystoreInstance() {
     return std::unique_ptr<KeystoreClient>(
-            static_cast<KeystoreClient*>(new keystore::KeystoreClientImpl));
+        static_cast<KeystoreClient*>(new keystore::KeystoreClientImpl));
 }
 
 void PrintTags(const AuthorizationSet& parameters) {
     for (auto iter = parameters.begin(); iter != parameters.end(); ++iter) {
-        printf("  %s\n", stringifyTag(iter->tag));
+        auto tag_str = toString(iter->tag);
+        printf("  %s\n", tag_str.c_str());
     }
 }
 
@@ -79,7 +77,7 @@
     AuthorizationSet hardware_enforced_characteristics;
     AuthorizationSet software_enforced_characteristics;
     auto result = keystore->generateKey("tmp", parameters, &hardware_enforced_characteristics,
-                                           &software_enforced_characteristics);
+                                        &software_enforced_characteristics);
     const char kBoldRedAbort[] = "\033[1;31mABORT\033[0m";
     if (!result.isOk()) {
         LOG(ERROR) << "Failed to generate key: " << result;
@@ -120,9 +118,7 @@
         .Padding(PaddingMode::RSA_PSS)
         .Authorization(TAG_NO_AUTH_REQUIRED);
     if (!sha256_only) {
-        parameters.Digest(Digest::SHA_2_224)
-            .Digest(Digest::SHA_2_384)
-            .Digest(Digest::SHA_2_512);
+        parameters.Digest(Digest::SHA_2_224).Digest(Digest::SHA_2_384).Digest(Digest::SHA_2_512);
     }
     return parameters;
 }
@@ -142,9 +138,7 @@
         .Digest(Digest::SHA_2_256)
         .Authorization(TAG_NO_AUTH_REQUIRED);
     if (!sha256_only) {
-        parameters.Digest(Digest::SHA_2_224)
-            .Digest(Digest::SHA_2_384)
-            .Digest(Digest::SHA_2_512);
+        parameters.Digest(Digest::SHA_2_224).Digest(Digest::SHA_2_384).Digest(Digest::SHA_2_512);
     }
     return parameters;
 }
@@ -205,7 +199,8 @@
     const char kBoldYellowWarning[] = "\033[1;33mWARNING\033[0m";
     if (test_for_0_3) {
         printf("%s: Testing for keymaster v0.3. "
-               "This does not meet Brillo requirements.\n", kBoldYellowWarning);
+               "This does not meet Brillo requirements.\n",
+               kBoldYellowWarning);
     }
     int test_count = 0;
     int fail_count = 0;
@@ -280,7 +275,7 @@
     AuthorizationSet hardware_enforced_characteristics;
     AuthorizationSet software_enforced_characteristics;
     auto result = keystore->generateKey(name, params, &hardware_enforced_characteristics,
-                                           &software_enforced_characteristics);
+                                        &software_enforced_characteristics);
     printf("GenerateKey: %d\n", int32_t(result));
     if (result.isOk()) {
         PrintKeyCharacteristics(hardware_enforced_characteristics,
@@ -294,7 +289,7 @@
     AuthorizationSet hardware_enforced_characteristics;
     AuthorizationSet software_enforced_characteristics;
     auto result = keystore->getKeyCharacteristics(name, &hardware_enforced_characteristics,
-                                                     &software_enforced_characteristics);
+                                                  &software_enforced_characteristics);
     printf("GetCharacteristics: %d\n", int32_t(result));
     if (result.isOk()) {
         PrintKeyCharacteristics(hardware_enforced_characteristics,
@@ -352,8 +347,8 @@
     sign_params.Digest(Digest::SHA_2_256);
     AuthorizationSet output_params;
     uint64_t handle;
-    auto result = keystore->beginOperation(KeyPurpose::SIGN, name, sign_params,
-                                              &output_params, &handle);
+    auto result =
+        keystore->beginOperation(KeyPurpose::SIGN, name, sign_params, &output_params, &handle);
     if (!result.isOk()) {
         printf("Sign: BeginOperation failed: %d\n", int32_t(result));
         return result;
@@ -377,8 +372,8 @@
     // We have a signature, now verify it.
     std::string signature_to_verify = output_data;
     output_data.clear();
-    result = keystore->beginOperation(KeyPurpose::VERIFY, name, sign_params, &output_params,
-                                      &handle);
+    result =
+        keystore->beginOperation(KeyPurpose::VERIFY, name, sign_params, &output_params, &handle);
     if (!result.isOk()) {
         printf("Verify: BeginOperation failed: %d\n", int32_t(result));
         return result;
diff --git a/keystore/keystore_client_impl.cpp b/keystore/keystore_client_impl.cpp
index d9a824b..4ff865a 100644
--- a/keystore/keystore_client_impl.cpp
+++ b/keystore/keystore_client_impl.cpp
@@ -28,10 +28,11 @@
 #include <utils/String16.h>
 #include <utils/String8.h>
 
-#include "keystore_client.pb.h"
-#include <keystore/authorization_set.h>
+#include <keystore/keymaster_types.h>
 #include <keystore/keystore_hidl_support.h>
 
+#include "keystore_client.pb.h"
+
 namespace {
 
 // Use the UID of the current process.
diff --git a/keystore/keystore_main.cpp b/keystore/keystore_main.cpp
index f4ccf04..56fe0d5 100644
--- a/keystore/keystore_main.cpp
+++ b/keystore/keystore_main.cpp
@@ -15,21 +15,23 @@
  */
 
 #include <android-base/logging.h>
+#include <android/security/IKeystoreService.h>
 #include <android/system/wifi/keystore/1.0/IKeystore.h>
 #include <binder/IPCThreadState.h>
 #include <binder/IServiceManager.h>
+#include <hidl/HidlTransportSupport.h>
 #include <utils/StrongPointer.h>
 #include <wifikeystorehal/keystore.h>
 
+#include <keystore/keystore_hidl_support.h>
+#include <keystore/keystore_return_types.h>
+
 #include "KeyStore.h"
 #include "Keymaster3.h"
 #include "entropy.h"
-#include "include/keystore/keystore_hidl_support.h"
-#include "include/keystore/keystore_return_types.h"
 #include "key_store_service.h"
 #include "legacy_keymaster_device_wrapper.h"
 #include "permissions.h"
-#include <android/security/IKeystoreService.h>
 
 /* KeyStore is a secured storage for key-value pairs. In this implementation,
  * each file stores one key-value pair. Keys are encoded in file names, and
diff --git a/keystore/keystore_tags_utils.cpp b/keystore/keystore_tags_utils.cpp
deleted file mode 100644
index 278348a..0000000
--- a/keystore/keystore_tags_utils.cpp
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
-**
-** Copyright 2016, 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 <keystore/keymaster_tags.h>
-
-namespace keystore {
-
-template<typename TagList>
-struct TagStringifier;
-
-template<typename ... Tags>
-struct TagStringifier<MetaList<Tags...>> {
-    template<TagType tag_type, Tag tag>
-    static TypedTag<tag_type, tag> chooseString(TypedTag<tag_type, tag> ttag, Tag runtime_tag,
-            const char** result) {
-        if (tag == runtime_tag) {
-            *result = Tag2String<tag>::value();
-        }
-        return ttag;
-    }
-    static const char* stringify(Tag tag) {
-        const char* result = "unknown tag";
-        [] (Tags&&...) {}(chooseString(Tags(), tag, &result)...);
-        return result;
-    }
-};
-
-const char* stringifyTag(Tag tag) {
-    return TagStringifier<all_tags_t>::stringify(tag);
-}
-
-}
diff --git a/keystore/keystore_utils.cpp b/keystore/keystore_utils.cpp
index 54f61cc..543a137 100644
--- a/keystore/keystore_utils.cpp
+++ b/keystore/keystore_utils.cpp
@@ -25,8 +25,9 @@
 #include <cutils/log.h>
 #include <private/android_filesystem_config.h>
 
-#include <keystore/authorization_set.h>
+#include <keystore/keymaster_types.h>
 #include <keystore/keystore_client.h>
+
 size_t readFully(int fd, uint8_t* data, size_t size) {
     size_t remaining = size;
     while (remaining > 0) {
diff --git a/keystore/keystore_utils.h b/keystore/keystore_utils.h
index 24844b7..7757f56 100644
--- a/keystore/keystore_utils.h
+++ b/keystore/keystore_utils.h
@@ -17,8 +17,7 @@
 #ifndef KEYSTORE_KEYSTORE_UTILS_H_
 #define KEYSTORE_KEYSTORE_UTILS_H_
 
-#include <stdint.h>
-
+#include <cstdint>
 #include <vector>
 
 #include <openssl/evp.h>
@@ -26,7 +25,7 @@
 
 #include <memory>
 
-#include <keystore/authorization_set.h>
+#include <keystore/keymaster_types.h>
 
 #include "blob.h"
 
@@ -65,6 +64,6 @@
     return result;
 }
 
-} // namespace keystore
+}  // namespace keystore
 
 #endif  // KEYSTORE_KEYSTORE_UTILS_H_
diff --git a/keystore/operation.h b/keystore/operation.h
index 6e97346..389f9f8 100644
--- a/keystore/operation.h
+++ b/keystore/operation.h
@@ -24,7 +24,7 @@
 #include <binder/IBinder.h>
 #include <utils/StrongPointer.h>
 
-#include <keystore/keymaster_tags.h>
+#include <keystore/keymaster_types.h>
 
 #include "Keymaster.h"
 
diff --git a/keystore/tests/Android.bp b/keystore/tests/Android.bp
index 6d8f75d..0ddaa00 100644
--- a/keystore/tests/Android.bp
+++ b/keystore/tests/Android.bp
@@ -5,6 +5,7 @@
         "-Wall",
         "-Werror",
         "-Wextra",
+        "-O0",
     ],
     srcs: [
         "auth_token_table_test.cpp",
@@ -14,7 +15,10 @@
     name: "keystore_unit_tests",
     tags: ["test"],
     static_libs: [
+        "libbase",
         "libgtest_main",
+        "libhidlbase",
+        "libkeymaster4support",
         "libkeystore_test",
         "liblog",
     ],
diff --git a/keystore/tests/auth_token_formatting_test.cpp b/keystore/tests/auth_token_formatting_test.cpp
index 511256f..2677718 100644
--- a/keystore/tests/auth_token_formatting_test.cpp
+++ b/keystore/tests/auth_token_formatting_test.cpp
@@ -16,18 +16,22 @@
 
 #include <gtest/gtest.h>
 
-#include <android/hardware/keymaster/3.0/types.h>
 #include <endian.h>
-#include <hardware/hw_auth_token.h>
 #include <hidl/HidlSupport.h>
 #include <keymaster/logger.h>
 
-#include "../auth_token_table.h"
+#include <keystore/keymaster_types.h>
 #include <keystore/keystore_hidl_support.h>
 
+#include "../auth_token_table.h"
+
 using std::vector;
 
 namespace keystore {
+
+using android::hardware::hidl_array;
+using android::hardware::hidl_vec;
+
 namespace test {
 
 namespace {
@@ -66,9 +70,6 @@
 
 }  // namespace
 
-using android::hardware::hidl_array;
-using android::hardware::hidl_vec;
-
 constexpr const uint8_t test_token[69] = {
     0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d,
     0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b,
diff --git a/keystore/tests/auth_token_table_test.cpp b/keystore/tests/auth_token_table_test.cpp
index 1a5ef90..511a78d 100644
--- a/keystore/tests/auth_token_table_test.cpp
+++ b/keystore/tests/auth_token_table_test.cpp
@@ -62,8 +62,8 @@
     AuthTokenTable table;
 }
 
-HardwareAuthToken make_token(uint64_t rsid, uint64_t ssid = 0, uint64_t challenge = 0,
-                             uint64_t timestamp = 0) {
+static HardwareAuthToken make_token(uint64_t rsid, uint64_t ssid = 0, uint64_t challenge = 0,
+                                    uint64_t timestamp = 0) {
     HardwareAuthToken token;
     token.userId = rsid;
     token.authenticatorId = ssid;