diff --git a/debuggerd/debuggerd.cpp b/debuggerd/debuggerd.cpp
index 039b8ec..b84a4e5 100644
--- a/debuggerd/debuggerd.cpp
+++ b/debuggerd/debuggerd.cpp
@@ -279,7 +279,7 @@
 
   char ehdr[EI_NIDENT];
   ssize_t bytes = TEMP_FAILURE_RETRY(read(fd, &ehdr, sizeof(ehdr)));
-  TEMP_FAILURE_RETRY(close(fd));
+  close(fd);
   if (bytes != (ssize_t) sizeof(ehdr) || memcmp(ELFMAG, ehdr, SELFMAG) != 0) {
     return false;
   }
@@ -304,14 +304,14 @@
 
   if (TEMP_FAILURE_RETRY(write(sock_fd, &msg, sizeof(msg))) != (ssize_t) sizeof(msg)) {
     ALOGE("Failed to write request to debuggerd32 socket: %s", strerror(errno));
-    TEMP_FAILURE_RETRY(close(sock_fd));
+    close(sock_fd);
     return;
   }
 
   char ack;
   if (TEMP_FAILURE_RETRY(read(sock_fd, &ack, 1)) == -1) {
     ALOGE("Failed to read ack from debuggerd32 socket: %s", strerror(errno));
-    TEMP_FAILURE_RETRY(close(sock_fd));
+    close(sock_fd);
     return;
   }
 
@@ -338,7 +338,7 @@
         break;
     }
   }
-  TEMP_FAILURE_RETRY(close(sock_fd));
+  close(sock_fd);
 }
 #endif
 
@@ -365,7 +365,7 @@
         ALOGE("debuggerd: Not allowed to redirect action %d to 32 bit debuggerd\n",
               request.action);
       }
-      TEMP_FAILURE_RETRY(close(fd));
+      close(fd);
       return;
     }
 #endif
diff --git a/fs_mgr/fs_mgr.c b/fs_mgr/fs_mgr.c
index 5f639b7..740f894 100644
--- a/fs_mgr/fs_mgr.c
+++ b/fs_mgr/fs_mgr.c
@@ -206,7 +206,7 @@
     }
 
     rc = ioctl(fd, BLKROSET, &ON);
-    TEMP_FAILURE_RETRY(close(fd));
+    close(fd);
 
     return rc;
 }
diff --git a/fs_mgr/fs_mgr_verity.c b/fs_mgr/fs_mgr_verity.c
index 6ef46ba..cc8c57e 100644
--- a/fs_mgr/fs_mgr_verity.c
+++ b/fs_mgr/fs_mgr_verity.c
@@ -169,20 +169,20 @@
 
     if (TEMP_FAILURE_RETRY(lseek64(data_device, 1024, SEEK_SET)) < 0) {
         ERROR("Error seeking to superblock");
-        TEMP_FAILURE_RETRY(close(data_device));
+        close(data_device);
         return -1;
     }
 
     if (TEMP_FAILURE_RETRY(read(data_device, &sb, sizeof(sb))) != sizeof(sb)) {
         ERROR("Error reading superblock");
-        TEMP_FAILURE_RETRY(close(data_device));
+        close(data_device);
         return -1;
     }
 
     ext4_parse_sb(&sb, &info);
     *device_size = info.len;
 
-    TEMP_FAILURE_RETRY(close(data_device));
+    close(data_device);
     return 0;
 }
 
@@ -301,7 +301,7 @@
 
 out:
     if (device != -1)
-        TEMP_FAILURE_RETRY(close(device));
+        close(device);
 
     if (retval != FS_MGR_SETUP_VERITY_SUCCESS) {
         free(*signature);
@@ -470,7 +470,7 @@
 
 out:
     if (fd != -1) {
-        TEMP_FAILURE_RETRY(close(fd));
+        close(fd);
     }
 
     return rc;
@@ -622,7 +622,7 @@
 
 out:
     if (fd != -1) {
-        TEMP_FAILURE_RETRY(close(fd));
+        close(fd);
     }
 
     return rc;
@@ -670,7 +670,7 @@
 
 out:
     if (fd != -1) {
-        TEMP_FAILURE_RETRY(close(fd));
+        close(fd);
     }
 
     return rc;
@@ -745,7 +745,7 @@
     free(signature);
 
     if (fd != -1) {
-        TEMP_FAILURE_RETRY(close(fd));
+        close(fd);
     }
 
     return rc;
@@ -913,7 +913,7 @@
     }
 
     if (fd) {
-        TEMP_FAILURE_RETRY(close(fd));
+        close(fd);
     }
 
     return rc;
diff --git a/gatekeeperd/Android.mk b/gatekeeperd/Android.mk
index be3d6fc..ce050ae 100644
--- a/gatekeeperd/Android.mk
+++ b/gatekeeperd/Android.mk
@@ -25,9 +25,12 @@
 	libgatekeeper \
 	liblog \
 	libhardware \
+	libbase \
 	libutils \
 	libcrypto \
 	libkeystore_binder
 LOCAL_STATIC_LIBRARIES := libscrypt_static
 LOCAL_C_INCLUDES := external/scrypt/lib/crypto
 include $(BUILD_EXECUTABLE)
+
+include $(call first-makefiles-under,$(LOCAL_PATH))
diff --git a/gatekeeperd/IGateKeeperService.cpp b/gatekeeperd/IGateKeeperService.cpp
index f5bbbf1..95fbfd1 100644
--- a/gatekeeperd/IGateKeeperService.cpp
+++ b/gatekeeperd/IGateKeeperService.cpp
@@ -50,18 +50,25 @@
 
             uint8_t *out = NULL;
             uint32_t outSize = 0;
-            status_t ret = enroll(uid, currentPasswordHandle, currentPasswordHandleSize,
+            int ret = enroll(uid, currentPasswordHandle, currentPasswordHandleSize,
                     currentPassword, currentPasswordSize, desiredPassword,
                     desiredPasswordSize, &out, &outSize);
 
             reply->writeNoException();
-            if (ret == NO_ERROR && outSize > 0 && out != NULL) {
+            reply->writeInt32(1);
+            if (ret == 0 && outSize > 0 && out != NULL) {
+                reply->writeInt32(GATEKEEPER_RESPONSE_OK);
+                reply->writeInt32(0);
+                reply->writeInt32(outSize);
                 reply->writeInt32(outSize);
                 void *buf = reply->writeInplace(outSize);
                 memcpy(buf, out, outSize);
-                free(out);
+                delete[] out;
+            } else if (ret > 0) {
+                reply->writeInt32(GATEKEEPER_RESPONSE_RETRY);
+                reply->writeInt32(ret);
             } else {
-                reply->writeInt32(-1);
+                reply->writeInt32(GATEKEEPER_RESPONSE_ERROR);
             }
             return NO_ERROR;
         }
@@ -78,10 +85,23 @@
                 static_cast<const uint8_t *>(data.readInplace(currentPasswordSize));
             if (!currentPassword) currentPasswordSize = 0;
 
-            status_t ret = verify(uid, (uint8_t *) currentPasswordHandle,
-                    currentPasswordHandleSize, (uint8_t *) currentPassword, currentPasswordSize);
+            bool request_reenroll = false;
+            int ret = verify(uid, (uint8_t *) currentPasswordHandle,
+                    currentPasswordHandleSize, (uint8_t *) currentPassword, currentPasswordSize,
+                    &request_reenroll);
+
             reply->writeNoException();
-            reply->writeInt32(ret == NO_ERROR ? 1 : 0);
+            reply->writeInt32(1);
+            if (ret == 0) {
+                reply->writeInt32(GATEKEEPER_RESPONSE_OK);
+                reply->writeInt32(request_reenroll ? 1 : 0);
+                reply->writeInt32(0); // no payload returned from this call
+            } else if (ret > 0) {
+                reply->writeInt32(GATEKEEPER_RESPONSE_RETRY);
+                reply->writeInt32(ret);
+            } else {
+                reply->writeInt32(GATEKEEPER_RESPONSE_ERROR);
+            }
             return NO_ERROR;
         }
         case VERIFY_CHALLENGE: {
@@ -101,17 +121,25 @@
 
             uint8_t *out = NULL;
             uint32_t outSize = 0;
-            status_t ret = verifyChallenge(uid, challenge, (uint8_t *) currentPasswordHandle,
+            bool request_reenroll = false;
+            int ret = verifyChallenge(uid, challenge, (uint8_t *) currentPasswordHandle,
                     currentPasswordHandleSize, (uint8_t *) currentPassword, currentPasswordSize,
-                    &out, &outSize);
+                    &out, &outSize, &request_reenroll);
             reply->writeNoException();
-            if (ret == NO_ERROR && outSize > 0 && out != NULL) {
+            reply->writeInt32(1);
+            if (ret == 0 && outSize > 0 && out != NULL) {
+                reply->writeInt32(GATEKEEPER_RESPONSE_OK);
+                reply->writeInt32(request_reenroll ? 1 : 0);
+                reply->writeInt32(outSize);
                 reply->writeInt32(outSize);
                 void *buf = reply->writeInplace(outSize);
                 memcpy(buf, out, outSize);
-                free(out);
+                delete[] out;
+            } else if (ret > 0) {
+                reply->writeInt32(GATEKEEPER_RESPONSE_RETRY);
+                reply->writeInt32(ret);
             } else {
-                reply->writeInt32(-1);
+                reply->writeInt32(GATEKEEPER_RESPONSE_ERROR);
             }
             return NO_ERROR;
         }
diff --git a/gatekeeperd/IGateKeeperService.h b/gatekeeperd/IGateKeeperService.h
index a777318..f070486 100644
--- a/gatekeeperd/IGateKeeperService.h
+++ b/gatekeeperd/IGateKeeperService.h
@@ -35,6 +35,12 @@
         CLEAR_SECURE_USER_ID = IBinder::FIRST_CALL_TRANSACTION + 4,
     };
 
+    enum {
+        GATEKEEPER_RESPONSE_OK = 0,
+        GATEKEEPER_RESPONSE_RETRY = 1,
+        GATEKEEPER_RESPONSE_ERROR = -1,
+    };
+
     // DECLARE_META_INTERFACE - C++ client interface not needed
     static const android::String16 descriptor;
     virtual const android::String16& getInterfaceDescriptor() const;
@@ -43,8 +49,13 @@
 
     /**
      * Enrolls a password with the GateKeeper. Returns 0 on success, negative on failure.
+     * Returns:
+     * - 0 on success
+     * - A timestamp T > 0 if the call has failed due to throttling and should not
+     *   be reattempted until T milliseconds have elapsed
+     * - -1 on failure
      */
-    virtual status_t enroll(uint32_t uid,
+    virtual int enroll(uint32_t uid,
             const uint8_t *current_password_handle, uint32_t current_password_handle_length,
             const uint8_t *current_password, uint32_t current_password_length,
             const uint8_t *desired_password, uint32_t desired_password_length,
@@ -52,21 +63,29 @@
 
     /**
      * Verifies a password previously enrolled with the GateKeeper.
-     * Returns 0 on success, negative on failure.
+     * Returns:
+     * - 0 on success
+     * - A timestamp T > 0 if the call has failed due to throttling and should not
+     *   be reattempted until T milliseconds have elapsed
+     * - -1 on failure
      */
-    virtual status_t verify(uint32_t uid, const uint8_t *enrolled_password_handle,
+    virtual int verify(uint32_t uid, const uint8_t *enrolled_password_handle,
             uint32_t enrolled_password_handle_length,
-            const uint8_t *provided_password, uint32_t provided_password_length) = 0;
+            const uint8_t *provided_password, uint32_t provided_password_length,
+            bool *request_reenroll) = 0;
 
     /**
      * Verifies a password previously enrolled with the GateKeeper.
-     * Returns 0 on success, negative on failure.
+     * Returns:
+     * - 0 on success
+     * - A timestamp T > 0 if the call has failed due to throttling and should not
+     *   be reattempted until T milliseconds have elapsed
+     * - -1 on failure
      */
-    virtual status_t verifyChallenge(uint32_t uid, uint64_t challenge,
+    virtual int verifyChallenge(uint32_t uid, uint64_t challenge,
             const uint8_t *enrolled_password_handle, uint32_t enrolled_password_handle_length,
             const uint8_t *provided_password, uint32_t provided_password_length,
-            uint8_t **auth_token, uint32_t *auth_token_length) = 0;
-
+            uint8_t **auth_token, uint32_t *auth_token_length, bool *request_reenroll) = 0;
     /**
      * Returns the secure user ID for the provided android user
      */
diff --git a/gatekeeperd/SoftGateKeeper.h b/gatekeeperd/SoftGateKeeper.h
new file mode 100644
index 0000000..1ae45e6
--- /dev/null
+++ b/gatekeeperd/SoftGateKeeper.h
@@ -0,0 +1,127 @@
+/*
+ * Copyright 2015 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 SOFT_GATEKEEPER_H_
+#define SOFT_GATEKEEPER_H_
+
+extern "C" {
+#include <openssl/rand.h>
+#include <crypto_scrypt.h>
+}
+
+#include <UniquePtr.h>
+#include <gatekeeper/gatekeeper.h>
+#include <iostream>
+#include <unordered_map>
+
+namespace gatekeeper {
+
+
+class SoftGateKeeper : public GateKeeper {
+public:
+    static const uint32_t SIGNATURE_LENGTH_BYTES = 32;
+
+    // scrypt params
+    static const uint64_t N = 16384;
+    static const uint32_t r = 8;
+    static const uint32_t p = 1;
+
+    static const int MAX_UINT_32_CHARS = 11;
+
+    SoftGateKeeper() {
+        key_.reset(new uint8_t[SIGNATURE_LENGTH_BYTES]);
+        memset(key_.get(), 0, SIGNATURE_LENGTH_BYTES);
+    }
+
+    virtual ~SoftGateKeeper() {
+    }
+
+    virtual bool GetAuthTokenKey(const uint8_t **auth_token_key,
+            uint32_t *length) const {
+        if (auth_token_key == NULL || length == NULL) return false;
+        *auth_token_key = const_cast<const uint8_t *>(key_.get());
+        *length = SIGNATURE_LENGTH_BYTES;
+        return true;
+    }
+
+    virtual void GetPasswordKey(const uint8_t **password_key, uint32_t *length) {
+        if (password_key == NULL || length == NULL) return;
+        *password_key = const_cast<const uint8_t *>(key_.get());
+        *length = SIGNATURE_LENGTH_BYTES;
+    }
+
+    virtual void ComputePasswordSignature(uint8_t *signature, uint32_t signature_length,
+            const uint8_t *, uint32_t, const uint8_t *password,
+            uint32_t password_length, salt_t salt) const {
+        if (signature == NULL) return;
+        crypto_scrypt(password, password_length, reinterpret_cast<uint8_t *>(&salt),
+                sizeof(salt), N, r, p, signature, signature_length);
+    }
+
+    virtual void GetRandom(void *random, uint32_t requested_length) const {
+        if (random == NULL) return;
+        RAND_pseudo_bytes((uint8_t *) random, requested_length);
+    }
+
+    virtual void ComputeSignature(uint8_t *signature, uint32_t signature_length,
+            const uint8_t *, uint32_t, const uint8_t *, const uint32_t) const {
+        if (signature == NULL) return;
+        memset(signature, 0, signature_length);
+    }
+
+    virtual uint64_t GetMillisecondsSinceBoot() const {
+        struct timespec time;
+        int res = clock_gettime(CLOCK_BOOTTIME, &time);
+        if (res < 0) return 0;
+        return (time.tv_sec * 1000) + (time.tv_nsec / 1000 / 1000);
+    }
+
+    virtual bool IsHardwareBacked() const {
+        return false;
+    }
+
+    virtual bool GetFailureRecord(uint32_t uid, secure_id_t user_id, failure_record_t *record) {
+        failure_record_t *stored = &failure_map_[uid];
+        if (user_id != stored->secure_user_id) {
+            stored->secure_user_id = user_id;
+            stored->last_checked_timestamp = 0;
+            stored->failure_counter = 0;
+        }
+        memcpy(record, stored, sizeof(*record));
+        return true;
+    }
+
+    virtual void ClearFailureRecord(uint32_t uid, secure_id_t user_id) {
+        failure_record_t *stored = &failure_map_[uid];
+        stored->secure_user_id = user_id;
+        stored->last_checked_timestamp = 0;
+        stored->failure_counter = 0;
+    }
+
+    virtual bool WriteFailureRecord(uint32_t uid, failure_record_t *record) {
+        failure_map_[uid] = *record;
+        return true;
+    }
+
+private:
+    UniquePtr<uint8_t> key_;
+    std::unordered_map<uint32_t, failure_record_t> failure_map_;
+};
+}
+
+#endif // SOFT_GATEKEEPER_H_
+
diff --git a/gatekeeperd/SoftGateKeeperDevice.cpp b/gatekeeperd/SoftGateKeeperDevice.cpp
index b96bf8d..f5e2ce6 100644
--- a/gatekeeperd/SoftGateKeeperDevice.cpp
+++ b/gatekeeperd/SoftGateKeeperDevice.cpp
@@ -13,8 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-#include <gatekeeper/soft_gatekeeper.h>
-
+#include "SoftGateKeeper.h"
 #include "SoftGateKeeperDevice.h"
 
 namespace android {
@@ -58,8 +57,11 @@
 
     impl_->Enroll(request, &response);
 
-    if (response.error != ERROR_NONE)
+    if (response.error == ERROR_RETRY) {
+        return response.retry_timeout;
+    } else if (response.error != ERROR_NONE) {
         return -EINVAL;
+    }
 
     *enrolled_password_handle = response.enrolled_password_handle.buffer.release();
     *enrolled_password_handle_length = response.enrolled_password_handle.length;
@@ -69,7 +71,8 @@
 int SoftGateKeeperDevice::verify(uint32_t uid,
         uint64_t challenge, const uint8_t *enrolled_password_handle,
         uint32_t enrolled_password_handle_length, const uint8_t *provided_password,
-        uint32_t provided_password_length, uint8_t **auth_token, uint32_t *auth_token_length) {
+        uint32_t provided_password_length, uint8_t **auth_token, uint32_t *auth_token_length,
+        bool *request_reenroll) {
 
     if (enrolled_password_handle == NULL ||
             provided_password == NULL) {
@@ -87,14 +90,21 @@
 
     impl_->Verify(request, &response);
 
-    if (response.error != ERROR_NONE)
-       return -EINVAL;
+    if (response.error == ERROR_RETRY) {
+        return response.retry_timeout;
+    } else if (response.error != ERROR_NONE) {
+        return -EINVAL;
+    }
 
     if (auth_token != NULL && auth_token_length != NULL) {
        *auth_token = response.auth_token.buffer.release();
        *auth_token_length = response.auth_token.length;
     }
 
+    if (request_reenroll != NULL) {
+        *request_reenroll = response.request_reenroll;
+    }
+
     return 0;
 }
 } // namespace android
diff --git a/gatekeeperd/SoftGateKeeperDevice.h b/gatekeeperd/SoftGateKeeperDevice.h
index c0b5047..51a8511 100644
--- a/gatekeeperd/SoftGateKeeperDevice.h
+++ b/gatekeeperd/SoftGateKeeperDevice.h
@@ -17,7 +17,8 @@
 #ifndef SOFT_GATEKEEPER_DEVICE_H_
 #define SOFT_GATEKEEPER_DEVICE_H_
 
-#include <gatekeeper/soft_gatekeeper.h>
+#include "SoftGateKeeper.h"
+
 #include <UniquePtr.h>
 
 using namespace gatekeeper;
@@ -65,7 +66,7 @@
     int verify(uint32_t uid, uint64_t challenge,
             const uint8_t *enrolled_password_handle, uint32_t enrolled_password_handle_length,
             const uint8_t *provided_password, uint32_t provided_password_length,
-            uint8_t **auth_token, uint32_t *auth_token_length);
+            uint8_t **auth_token, uint32_t *auth_token_length, bool *request_reenroll);
 private:
     UniquePtr<GateKeeper> impl_;
 };
diff --git a/gatekeeperd/gatekeeperd.cpp b/gatekeeperd/gatekeeperd.cpp
index 72c7ba2..ad16fa5 100644
--- a/gatekeeperd/gatekeeperd.cpp
+++ b/gatekeeperd/gatekeeperd.cpp
@@ -102,7 +102,7 @@
         }
     }
 
-    virtual status_t enroll(uint32_t uid,
+    virtual int enroll(uint32_t uid,
             const uint8_t *current_password_handle, uint32_t current_password_handle_length,
             const uint8_t *current_password, uint32_t current_password_length,
             const uint8_t *desired_password, uint32_t desired_password_length,
@@ -132,29 +132,29 @@
                     enrolled_password_handle, enrolled_password_handle_length);
         }
 
-        if (ret >= 0) {
+        if (ret == 0) {
             gatekeeper::password_handle_t *handle =
                     reinterpret_cast<gatekeeper::password_handle_t *>(*enrolled_password_handle);
             store_sid(uid, handle->user_id);
-            return NO_ERROR;
         }
-        return UNKNOWN_ERROR;
+
+        return ret;
     }
 
-    virtual status_t verify(uint32_t uid,
+    virtual int verify(uint32_t uid,
             const uint8_t *enrolled_password_handle, uint32_t enrolled_password_handle_length,
-            const uint8_t *provided_password, uint32_t provided_password_length) {
+            const uint8_t *provided_password, uint32_t provided_password_length, bool *request_reenroll) {
         uint8_t *auth_token;
         uint32_t auth_token_length;
         return verifyChallenge(uid, 0, enrolled_password_handle, enrolled_password_handle_length,
                 provided_password, provided_password_length,
-                &auth_token, &auth_token_length);
+                &auth_token, &auth_token_length, request_reenroll);
     }
 
-    virtual status_t verifyChallenge(uint32_t uid, uint64_t challenge,
+    virtual int verifyChallenge(uint32_t uid, uint64_t challenge,
             const uint8_t *enrolled_password_handle, uint32_t enrolled_password_handle_length,
             const uint8_t *provided_password, uint32_t provided_password_length,
-            uint8_t **auth_token, uint32_t *auth_token_length) {
+            uint8_t **auth_token, uint32_t *auth_token_length, bool *request_reenroll) {
         IPCThreadState* ipc = IPCThreadState::self();
         const int calling_pid = ipc->getCallingPid();
         const int calling_uid = ipc->getCallingUid();
@@ -170,14 +170,16 @@
         if (device) {
             ret = device->verify(device, uid, challenge,
                 enrolled_password_handle, enrolled_password_handle_length,
-                provided_password, provided_password_length, auth_token, auth_token_length);
+                provided_password, provided_password_length, auth_token, auth_token_length,
+                request_reenroll);
         } else {
             ret = soft_device->verify(uid, challenge,
                 enrolled_password_handle, enrolled_password_handle_length,
-                provided_password, provided_password_length, auth_token, auth_token_length);
+                provided_password, provided_password_length, auth_token, auth_token_length,
+                request_reenroll);
         }
 
-        if (ret >= 0 && *auth_token != NULL && *auth_token_length > 0) {
+        if (ret == 0 && *auth_token != NULL && *auth_token_length > 0) {
             // TODO: cache service?
             sp<IServiceManager> sm = defaultServiceManager();
             sp<IBinder> binder = sm->getService(String16("android.security.keystore"));
@@ -192,13 +194,12 @@
             }
         }
 
-        if (ret >= 0) {
+        if (ret == 0) {
             maybe_store_sid(uid, reinterpret_cast<const gatekeeper::password_handle_t *>(
                         enrolled_password_handle)->user_id);
-            return NO_ERROR;
         }
 
-        return UNKNOWN_ERROR;
+        return ret;
     }
 
     virtual uint64_t getSecureUserId(uint32_t uid) {
diff --git a/gatekeeperd/tests/Android.mk b/gatekeeperd/tests/Android.mk
new file mode 100644
index 0000000..6fc4ac0
--- /dev/null
+++ b/gatekeeperd/tests/Android.mk
@@ -0,0 +1,29 @@
+#
+# Copyright (C) 2015 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.
+#
+
+LOCAL_PATH:= $(call my-dir)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := gatekeeperd-unit-tests
+LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
+LOCAL_CFLAGS += -g -Wall -Werror -std=gnu++11 -Wno-missing-field-initializers
+LOCAL_SHARED_LIBRARIES := libgatekeeper libcrypto
+LOCAL_STATIC_LIBRARIES := libscrypt_static
+LOCAL_C_INCLUDES := external/scrypt/lib/crypto
+LOCAL_SRC_FILES := \
+	gatekeeper_test.cpp
+include $(BUILD_NATIVE_TEST)
+
diff --git a/gatekeeperd/tests/gatekeeper_test.cpp b/gatekeeperd/tests/gatekeeper_test.cpp
new file mode 100644
index 0000000..15b2b69
--- /dev/null
+++ b/gatekeeperd/tests/gatekeeper_test.cpp
@@ -0,0 +1,204 @@
+/*
+ * Copyright 2015 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 <gtest/gtest.h>
+#include <UniquePtr.h>
+#include <iostream>
+
+#include <hardware/hw_auth_token.h>
+
+#include "../SoftGateKeeper.h"
+
+using ::gatekeeper::SizedBuffer;
+using ::testing::Test;
+using ::gatekeeper::EnrollRequest;
+using ::gatekeeper::EnrollResponse;
+using ::gatekeeper::VerifyRequest;
+using ::gatekeeper::VerifyResponse;
+using ::gatekeeper::SoftGateKeeper;
+using ::gatekeeper::secure_id_t;
+
+static void do_enroll(SoftGateKeeper &gatekeeper, EnrollResponse *response) {
+    SizedBuffer password;
+
+    password.buffer.reset(new uint8_t[16]);
+    password.length = 16;
+    memset(password.buffer.get(), 0, 16);
+    EnrollRequest request(0, NULL, &password, NULL);
+
+    gatekeeper.Enroll(request, response);
+}
+
+TEST(GateKeeperTest, EnrollSuccess) {
+    SoftGateKeeper gatekeeper;
+    EnrollResponse response;
+    do_enroll(gatekeeper, &response);
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_NONE, response.error);
+}
+
+TEST(GateKeeperTest, EnrollBogusData) {
+    SoftGateKeeper gatekeeper;
+    SizedBuffer password;
+    EnrollResponse response;
+
+    EnrollRequest request(0, NULL, &password, NULL);
+
+    gatekeeper.Enroll(request, &response);
+
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_INVALID, response.error);
+}
+
+TEST(GateKeeperTest, VerifySuccess) {
+    SoftGateKeeper gatekeeper;
+    SizedBuffer provided_password;
+    EnrollResponse enroll_response;
+
+    provided_password.buffer.reset(new uint8_t[16]);
+    provided_password.length = 16;
+    memset(provided_password.buffer.get(), 0, 16);
+
+    do_enroll(gatekeeper, &enroll_response);
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_NONE, enroll_response.error);
+    VerifyRequest request(0, 1, &enroll_response.enrolled_password_handle,
+            &provided_password);
+    VerifyResponse response;
+
+    gatekeeper.Verify(request, &response);
+
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_NONE, response.error);
+
+    hw_auth_token_t *auth_token =
+        reinterpret_cast<hw_auth_token_t *>(response.auth_token.buffer.get());
+
+    ASSERT_EQ((uint32_t) HW_AUTH_PASSWORD, ntohl(auth_token->authenticator_type));
+    ASSERT_EQ((uint64_t) 1, auth_token->challenge);
+    ASSERT_NE(~((uint32_t) 0), auth_token->timestamp);
+    ASSERT_NE((uint64_t) 0, auth_token->user_id);
+    ASSERT_NE((uint64_t) 0, auth_token->authenticator_id);
+}
+
+TEST(GateKeeperTest, TrustedReEnroll) {
+    SoftGateKeeper gatekeeper;
+    SizedBuffer provided_password;
+    EnrollResponse enroll_response;
+    SizedBuffer password_handle;
+
+    // do_enroll enrolls an all 0 password
+    provided_password.buffer.reset(new uint8_t[16]);
+    provided_password.length = 16;
+    memset(provided_password.buffer.get(), 0, 16);
+    do_enroll(gatekeeper, &enroll_response);
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_NONE, enroll_response.error);
+
+    // keep a copy of the handle
+    password_handle.buffer.reset(new uint8_t[enroll_response.enrolled_password_handle.length]);
+    password_handle.length = enroll_response.enrolled_password_handle.length;
+    memcpy(password_handle.buffer.get(), enroll_response.enrolled_password_handle.buffer.get(),
+            password_handle.length);
+
+    // verify first password
+    VerifyRequest request(0, 0, &enroll_response.enrolled_password_handle,
+            &provided_password);
+    VerifyResponse response;
+    gatekeeper.Verify(request, &response);
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_NONE, response.error);
+    hw_auth_token_t *auth_token =
+        reinterpret_cast<hw_auth_token_t *>(response.auth_token.buffer.get());
+
+    secure_id_t secure_id = auth_token->user_id;
+
+    // enroll new password
+    provided_password.buffer.reset(new uint8_t[16]);
+    provided_password.length = 16;
+    memset(provided_password.buffer.get(), 0, 16);
+    SizedBuffer password;
+    password.buffer.reset(new uint8_t[16]);
+    memset(password.buffer.get(), 1, 16);
+    password.length = 16;
+    EnrollRequest enroll_request(0, &password_handle, &password, &provided_password);
+    gatekeeper.Enroll(enroll_request, &enroll_response);
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_NONE, enroll_response.error);
+
+    // verify new password
+    password.buffer.reset(new uint8_t[16]);
+    memset(password.buffer.get(), 1, 16);
+    password.length = 16;
+    VerifyRequest new_request(0, 0, &enroll_response.enrolled_password_handle,
+            &password);
+    gatekeeper.Verify(new_request, &response);
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_NONE, response.error);
+    ASSERT_EQ(secure_id,
+        reinterpret_cast<hw_auth_token_t *>(response.auth_token.buffer.get())->user_id);
+}
+
+
+TEST(GateKeeperTest, UntrustedReEnroll) {
+    SoftGateKeeper gatekeeper;
+    SizedBuffer provided_password;
+    EnrollResponse enroll_response;
+
+    // do_enroll enrolls an all 0 password
+    provided_password.buffer.reset(new uint8_t[16]);
+    provided_password.length = 16;
+    memset(provided_password.buffer.get(), 0, 16);
+    do_enroll(gatekeeper, &enroll_response);
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_NONE, enroll_response.error);
+
+    // verify first password
+    VerifyRequest request(0, 0, &enroll_response.enrolled_password_handle,
+            &provided_password);
+    VerifyResponse response;
+    gatekeeper.Verify(request, &response);
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_NONE, response.error);
+    hw_auth_token_t *auth_token =
+        reinterpret_cast<hw_auth_token_t *>(response.auth_token.buffer.get());
+
+    secure_id_t secure_id = auth_token->user_id;
+
+    // enroll new password
+    SizedBuffer password;
+    password.buffer.reset(new uint8_t[16]);
+    memset(password.buffer.get(), 1, 16);
+    password.length = 16;
+    EnrollRequest enroll_request(0, NULL, &password, NULL);
+    gatekeeper.Enroll(enroll_request, &enroll_response);
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_NONE, enroll_response.error);
+
+    // verify new password
+    password.buffer.reset(new uint8_t[16]);
+    memset(password.buffer.get(), 1, 16);
+    password.length = 16;
+    VerifyRequest new_request(0, 0, &enroll_response.enrolled_password_handle,
+            &password);
+    gatekeeper.Verify(new_request, &response);
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_NONE, response.error);
+    ASSERT_NE(secure_id,
+        reinterpret_cast<hw_auth_token_t *>(response.auth_token.buffer.get())->user_id);
+}
+
+
+TEST(GateKeeperTest, VerifyBogusData) {
+    SoftGateKeeper gatekeeper;
+    SizedBuffer provided_password;
+    SizedBuffer password_handle;
+    VerifyResponse response;
+
+    VerifyRequest request(0, 0, &provided_password, &password_handle);
+
+    gatekeeper.Verify(request, &response);
+
+    ASSERT_EQ(::gatekeeper::gatekeeper_error_t::ERROR_INVALID, response.error);
+}
diff --git a/include/system/graphics.h b/include/system/graphics.h
index da24fb8..ff3fd88 100644
--- a/include/system/graphics.h
+++ b/include/system/graphics.h
@@ -147,7 +147,8 @@
      * When used with ANativeWindow, the dataSpace field describes the color
      * space of the buffer, except that dataSpace field
      * HAL_DATASPACE_DEPTH indicates that this buffer contains a depth
-     * image where each sample is a distance value measured by a depth camera.
+     * image where each sample is a distance value measured by a depth camera,
+     * plus an associated confidence value.
      */
     HAL_PIXEL_FORMAT_Y16    = 0x20363159,
 
@@ -481,25 +482,31 @@
  * When locking a native buffer of the above format and dataSpace value,
  * the vaddr pointer can be cast to this structure.
  *
- * A variable-length list of (x,y,z) 3D points, as floats.
+ * A variable-length list of (x,y,z, confidence) 3D points, as floats.  (x, y,
+ * z) represents a measured point's position, with the coordinate system defined
+ * by the data source.  Confidence represents the estimated likelihood that this
+ * measurement is correct. It is between 0.f and 1.f, inclusive, with 1.f ==
+ * 100% confidence.
  *
  * @num_points is the number of points in the list
  *
  * @xyz_points is the flexible array of floating-point values.
- *   It contains (num_points) * 3 floats.
+ *   It contains (num_points) * 4 floats.
  *
  *   For example:
  *     android_depth_points d = get_depth_buffer();
  *     struct {
- *       float x; float y; float z;
+ *       float x; float y; float z; float confidence;
  *     } firstPoint, lastPoint;
  *
- *     firstPoint.x = d.xyz_points[0];
- *     firstPoint.y = d.xyz_points[1];
- *     firstPoint.z = d.xyz_points[2];
- *     lastPoint.x = d.xyz_points[(d.num_points - 1) * 3 + 0];
- *     lastPoint.y = d.xyz_points[(d.num_points - 1) * 3 + 1];
- *     lastPoint.z = d.xyz_points[(d.num_points - 1) * 3 + 2];
+ *     firstPoint.x = d.xyzc_points[0];
+ *     firstPoint.y = d.xyzc_points[1];
+ *     firstPoint.z = d.xyzc_points[2];
+ *     firstPoint.confidence = d.xyzc_points[3];
+ *     lastPoint.x = d.xyzc_points[(d.num_points - 1) * 4 + 0];
+ *     lastPoint.y = d.xyzc_points[(d.num_points - 1) * 4 + 1];
+ *     lastPoint.z = d.xyzc_points[(d.num_points - 1) * 4 + 2];
+ *     lastPoint.confidence = d.xyzc_points[(d.num_points - 1) * 4 + 3];
  */
 
 struct android_depth_points {
@@ -508,7 +515,7 @@
     /** reserved for future use, set to 0 by gralloc's (*lock)() */
     uint32_t reserved[8];
 
-    float xyz_points[];
+    float xyzc_points[];
 };
 
 /**
@@ -730,9 +737,18 @@
     /*
      * The buffer contains depth ranging measurements from a depth camera.
      * This value is valid with formats:
-     *    HAL_PIXEL_FORMAT_Y16: 16-bit single channel depth image.
+     *    HAL_PIXEL_FORMAT_Y16: 16-bit samples, consisting of a depth measurement
+     *       and an associated confidence value. The 3 MSBs of the sample make
+     *       up the confidence value, and the low 13 LSBs of the sample make up
+     *       the depth measurement.
+     *       For the confidence section, 0 means 100% confidence, 1 means 0%
+     *       confidence. The mapping to a linear float confidence value between
+     *       0.f and 1.f can be obtained with
+     *         float confidence = (((depthSample >> 13) - 1) & 0x7) / 7.0f;
+     *       The depth measurement can be extracted simply with
+     *         uint16_t range = (depthSample & 0x1FFF);
      *    HAL_PIXEL_FORMAT_BLOB: A depth point cloud, as
-     *       a variable-length float (x,y,z) coordinate point list.
+     *       a variable-length float (x,y,z, confidence) coordinate point list.
      *       The point cloud will be represented with the android_depth_points
      *       structure.
      */
diff --git a/include/utils/BlobCache.h b/include/utils/BlobCache.h
index 7d621e4..65dca9f 100644
--- a/include/utils/BlobCache.h
+++ b/include/utils/BlobCache.h
@@ -185,6 +185,12 @@
         // mNumEntries is number of cache entries following the header in the
         // data.
         size_t mNumEntries;
+
+        // mBuildId is the build id of the device when the cache was created.
+        // When an update to the build happens (via an OTA or other update) this
+        // is used to invalidate the cache.
+        int mBuildIdLength;
+        char mBuildId[];
     };
 
     // An EntryHeader is the header for a serialized cache entry.  No need to
diff --git a/init/util.cpp b/init/util.cpp
index b3947f7..a5392c6 100644
--- a/init/util.cpp
+++ b/init/util.cpp
@@ -170,7 +170,7 @@
     }
 
     bool okay = android::base::ReadFdToString(fd, content);
-    TEMP_FAILURE_RETRY(close(fd));
+    close(fd);
     return okay;
 }
 
@@ -184,7 +184,7 @@
     if (result == -1) {
         NOTICE("write_file: Unable to write to '%s': %s\n", path, strerror(errno));
     }
-    TEMP_FAILURE_RETRY(close(fd));
+    close(fd);
     return result;
 }
 
diff --git a/libcutils/debugger.c b/libcutils/debugger.c
index 4558719..3407ec3 100644
--- a/libcutils/debugger.c
+++ b/libcutils/debugger.c
@@ -68,7 +68,7 @@
   }
 
   if (send_request(sock_fd, &msg, sizeof(msg)) < 0) {
-    TEMP_FAILURE_RETRY(close(sock_fd));
+    close(sock_fd);
     return -1;
   }
 
@@ -95,7 +95,7 @@
       break;
     }
   }
-  TEMP_FAILURE_RETRY(close(sock_fd));
+  close(sock_fd);
   return result;
 }
 
@@ -124,6 +124,6 @@
       memcpy(pathbuf, buffer, n + 1);
     }
   }
-  TEMP_FAILURE_RETRY(close(sock_fd));
+  close(sock_fd);
   return result;
 }
diff --git a/libutils/Android.mk b/libutils/Android.mk
index f675a94..40cd31e 100644
--- a/libutils/Android.mk
+++ b/libutils/Android.mk
@@ -16,7 +16,6 @@
 
 commonSources:= \
 	BasicHashtable.cpp \
-	BlobCache.cpp \
 	CallStack.cpp \
 	FileMap.cpp \
 	JenkinsHash.cpp \
@@ -74,6 +73,7 @@
 # we have the common sources, plus some device-specific stuff
 LOCAL_SRC_FILES:= \
 	$(commonSources) \
+	BlobCache.cpp \
 	Looper.cpp \
 	Trace.cpp
 
@@ -83,7 +83,8 @@
 LOCAL_CFLAGS += -Werror
 
 LOCAL_STATIC_LIBRARIES := \
-	libcutils
+	libcutils \
+	libc
 
 LOCAL_SHARED_LIBRARIES := \
         libbacktrace \
diff --git a/libutils/BlobCache.cpp b/libutils/BlobCache.cpp
index 0ea09cf..126995b 100644
--- a/libutils/BlobCache.cpp
+++ b/libutils/BlobCache.cpp
@@ -25,13 +25,15 @@
 #include <utils/Errors.h>
 #include <utils/Log.h>
 
+#include <cutils/properties.h>
+
 namespace android {
 
 // BlobCache::Header::mMagicNumber value
 static const uint32_t blobCacheMagic = ('_' << 24) + ('B' << 16) + ('b' << 8) + '$';
 
 // BlobCache::Header::mBlobCacheVersion value
-static const uint32_t blobCacheVersion = 2;
+static const uint32_t blobCacheVersion = 3;
 
 // BlobCache::Header::mDeviceVersion value
 static const uint32_t blobCacheDeviceVersion = 1;
@@ -165,7 +167,7 @@
 }
 
 size_t BlobCache::getFlattenedSize() const {
-    size_t size = align4(sizeof(Header));
+    size_t size = align4(sizeof(Header) + PROPERTY_VALUE_MAX);
     for (size_t i = 0; i < mCacheEntries.size(); i++) {
         const CacheEntry& e(mCacheEntries[i]);
         sp<Blob> keyBlob = e.getKey();
@@ -187,10 +189,13 @@
     header->mBlobCacheVersion = blobCacheVersion;
     header->mDeviceVersion = blobCacheDeviceVersion;
     header->mNumEntries = mCacheEntries.size();
+    char buildId[PROPERTY_VALUE_MAX];
+    header->mBuildIdLength = property_get("ro.build.id", buildId, "");
+    memcpy(header->mBuildId, buildId, header->mBuildIdLength);
 
     // Write cache entries
     uint8_t* byteBuffer = reinterpret_cast<uint8_t*>(buffer);
-    off_t byteOffset = align4(sizeof(Header));
+    off_t byteOffset = align4(sizeof(Header) + header->mBuildIdLength);
     for (size_t i = 0; i < mCacheEntries.size(); i++) {
         const CacheEntry& e(mCacheEntries[i]);
         sp<Blob> keyBlob = e.getKey();
@@ -239,15 +244,19 @@
         ALOGE("unflatten: bad magic number: %" PRIu32, header->mMagicNumber);
         return BAD_VALUE;
     }
+    char buildId[PROPERTY_VALUE_MAX];
+    int len = property_get("ro.build.id", buildId, "");
     if (header->mBlobCacheVersion != blobCacheVersion ||
-            header->mDeviceVersion != blobCacheDeviceVersion) {
+            header->mDeviceVersion != blobCacheDeviceVersion ||
+            len != header->mBuildIdLength ||
+            strncmp(buildId, header->mBuildId, len)) {
         // We treat version mismatches as an empty cache.
         return OK;
     }
 
     // Read cache entries
     const uint8_t* byteBuffer = reinterpret_cast<const uint8_t*>(buffer);
-    off_t byteOffset = align4(sizeof(Header));
+    off_t byteOffset = align4(sizeof(Header) + header->mBuildIdLength);
     size_t numEntries = header->mNumEntries;
     for (size_t i = 0; i < numEntries; i++) {
         if (byteOffset + sizeof(EntryHeader) > size) {