diff --git a/nearby/service/Android.bp b/nearby/service/Android.bp
index 13dd6a9..b33d593 100644
--- a/nearby/service/Android.bp
+++ b/nearby/service/Android.bp
@@ -36,6 +36,11 @@
         // pre-jarjar symbols are needed so that nearby-service can reference the original class
         // names at compile time
         "framework-nearby-pre-jarjar",
+        "error_prone_annotations",
+    ],
+    static_libs: [
+        "androidx.annotation_annotation",
+        "guava",
     ],
     sdk_version: "system_server_current",
 
@@ -55,4 +60,4 @@
     apex_available: [
         "com.android.nearby",
     ],
-}
\ No newline at end of file
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/BluetoothException.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/BluetoothException.java
index 83d4a23..db2e1cc 100644
--- a/nearby/service/java/com/android/server/nearby/common/bluetooth/BluetoothException.java
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/BluetoothException.java
@@ -20,10 +20,12 @@
  * {@link Exception} thrown during a Bluetooth operation.
  */
 public class BluetoothException extends Exception {
+    /** Constructor. */
     public BluetoothException(String message) {
         super(message);
     }
 
+    /** Constructor. */
     public BluetoothException(String message, Throwable throwable) {
         super(message, throwable);
     }
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/BluetoothGattException.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/BluetoothGattException.java
new file mode 100644
index 0000000..5ac4882
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/BluetoothGattException.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth;
+
+/**
+ * Exception for Bluetooth GATT operations.
+ */
+public class BluetoothGattException extends BluetoothException {
+    private final int mErrorCode;
+
+    /** Constructor. */
+    public BluetoothGattException(String message, int errorCode) {
+        super(message);
+        mErrorCode = errorCode;
+    }
+
+    /** Constructor. */
+    public BluetoothGattException(String message, int errorCode, Throwable cause) {
+        super(message, cause);
+        mErrorCode = errorCode;
+    }
+
+    /** Returns Gatt error code. */
+    public int getGattErrorCode() {
+        return mErrorCode;
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/BluetoothTimeoutException.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/BluetoothTimeoutException.java
new file mode 100644
index 0000000..30fd188
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/BluetoothTimeoutException.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth;
+
+/**
+ * {@link Exception} thrown during a Bluetooth operation when a timeout occurs.
+ */
+public class BluetoothTimeoutException extends BluetoothException {
+
+    /** Constructor. */
+    public BluetoothTimeoutException(String message) {
+        super(message);
+    }
+
+    /** Constructor. */
+    public BluetoothTimeoutException(String message, Throwable throwable) {
+        super(message, throwable);
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/AesEcbSingleBlockEncryption.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/AesEcbSingleBlockEncryption.java
new file mode 100644
index 0000000..547931e
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/AesEcbSingleBlockEncryption.java
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+import android.annotation.SuppressLint;
+
+import java.security.GeneralSecurityException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.Cipher;
+import javax.crypto.KeyGenerator;
+import javax.crypto.spec.SecretKeySpec;
+
+/**
+ * Utilities used for encrypting and decrypting Fast Pair packets.
+ */
+// SuppressLint for ""ecb encryption mode should not be used".
+// Reasons:
+//    1. FastPair data is guaranteed to be only 1 AES block in size, ECB is secure.
+//    2. In each case, the encrypted data is less than 16-bytes and is
+//       padded up to 16-bytes using random data to fill the rest of the byte array,
+//       so the plaintext will never be the same.
+@SuppressLint("GetInstance")
+public final class AesEcbSingleBlockEncryption {
+
+    public static final int AES_BLOCK_LENGTH = 16;
+    public static final int KEY_LENGTH = 16;
+
+    private AesEcbSingleBlockEncryption() {
+    }
+
+    /**
+     * Generates a 16-byte AES key.
+     */
+    public static byte[] generateKey() throws NoSuchAlgorithmException {
+        KeyGenerator generator = KeyGenerator.getInstance("AES");
+        generator.init(KEY_LENGTH * 8); // Ensure a 16-byte key is always used.
+        return generator.generateKey().getEncoded();
+    }
+
+    /**
+     * Encrypts data with the provided secret.
+     */
+    public static byte[] encrypt(byte[] secret, byte[] data) throws GeneralSecurityException {
+        return doEncryption(Cipher.ENCRYPT_MODE, secret, data);
+    }
+
+    /**
+     * Decrypts data with the provided secret.
+     */
+    public static byte[] decrypt(byte[] secret, byte[] data) throws GeneralSecurityException {
+        return doEncryption(Cipher.DECRYPT_MODE, secret, data);
+    }
+
+    private static byte[] doEncryption(int mode, byte[] secret, byte[] data)
+            throws GeneralSecurityException {
+        if (data.length != AES_BLOCK_LENGTH) {
+            throw new IllegalArgumentException("This encrypter only supports 16-byte inputs.");
+        }
+        Cipher cipher = Cipher.getInstance("AES/ECB/NoPadding");
+        cipher.init(mode, new SecretKeySpec(secret, "AES"));
+        return cipher.doFinal(data);
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/BluetoothAddress.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/BluetoothAddress.java
new file mode 100644
index 0000000..9bb5a86
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/BluetoothAddress.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+import static com.google.common.io.BaseEncoding.base16;
+
+import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.BluetoothDevice;
+import android.content.Context;
+import android.provider.Settings;
+
+import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
+
+import com.google.common.base.Ascii;
+import com.google.common.io.BaseEncoding;
+
+import java.util.Locale;
+
+/** Utils for dealing with Bluetooth addresses. */
+public final class BluetoothAddress {
+
+    private static final BaseEncoding ENCODING = base16().upperCase().withSeparator(":", 2);
+
+    @VisibleForTesting
+    static final String SECURE_SETTINGS_KEY_BLUETOOTH_ADDRESS = "bluetooth_address";
+
+    /**
+     * @return The string format used by e.g. {@link android.bluetooth.BluetoothDevice}. Upper case.
+     *     Example: "AA:BB:CC:11:22:33"
+     */
+    public static String encode(byte[] address) {
+        return ENCODING.encode(address);
+    }
+
+    /**
+     * @param address The string format used by e.g. {@link android.bluetooth.BluetoothDevice}.
+     *     Case-insensitive. Example: "AA:BB:CC:11:22:33"
+     */
+    public static byte[] decode(String address) {
+        return ENCODING.decode(address.toUpperCase(Locale.US));
+    }
+
+    /**
+     * Get public bluetooth address.
+     *
+     * @param context a valid {@link Context} instance.
+     */
+    public static @Nullable byte[] getPublicAddress(Context context) {
+        String publicAddress =
+                Settings.Secure.getString(
+                        context.getContentResolver(), SECURE_SETTINGS_KEY_BLUETOOTH_ADDRESS);
+        return publicAddress != null && BluetoothAdapter.checkBluetoothAddress(publicAddress)
+                ? decode(publicAddress)
+                : null;
+    }
+
+    /**
+     * Hides partial information of Bluetooth address.
+     * ex1: input is null, output should be empty string
+     * ex2: input is String(AA:BB:CC), output should be AA:BB:CC
+     * ex3: input is String(AA:BB:CC:DD:EE:FF), output should be XX:XX:XX:XX:EE:FF
+     * ex4: input is String(Aa:Bb:Cc:Dd:Ee:Ff), output should be XX:XX:XX:XX:EE:FF
+     * ex5: input is BluetoothDevice(AA:BB:CC:DD:EE:FF), output should be XX:XX:XX:XX:EE:FF
+     */
+    public static String maskBluetoothAddress(@Nullable Object address) {
+        if (address == null) {
+            return "";
+        }
+
+        if (address instanceof String) {
+            String originalAddress = (String) address;
+            String upperCasedAddress = Ascii.toUpperCase(originalAddress);
+            if (!BluetoothAdapter.checkBluetoothAddress(upperCasedAddress)) {
+                return originalAddress;
+            }
+            return convert(upperCasedAddress);
+        } else if (address instanceof BluetoothDevice) {
+            return convert(((BluetoothDevice) address).getAddress());
+        }
+
+        // For others, returns toString().
+        return address.toString();
+    }
+
+    private static String convert(String address) {
+        return "XX:XX:XX:XX:" + address.substring(12);
+    }
+
+    private BluetoothAddress() {}
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/Bytes.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/Bytes.java
new file mode 100644
index 0000000..637cd03
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/Bytes.java
@@ -0,0 +1,118 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+import androidx.annotation.Nullable;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.ShortBuffer;
+import java.util.Arrays;
+
+/** Represents a block of bytes, with hashCode and equals. */
+public abstract class Bytes {
+    private static final char[] sHexDigits = "0123456789abcdef".toCharArray();
+    private final byte[] mBytes;
+
+    /**
+     * A logical value consisting of one or more bytes in the given order (little-endian, i.e.
+     * LSO...MSO, or big-endian, i.e. MSO...LSO). E.g. the Fast Pair Model ID is a 3-byte value,
+     * and a Bluetooth device address is a 6-byte value.
+     */
+    public static class Value extends Bytes {
+        private final ByteOrder mByteOrder;
+
+        /**
+         * Constructor.
+         */
+        public Value(byte[] bytes, ByteOrder byteOrder) {
+            super(bytes);
+            this.mByteOrder = byteOrder;
+        }
+
+        /**
+         * Gets bytes.
+         */
+        public byte[] getBytes(ByteOrder byteOrder) {
+            return this.mByteOrder.equals(byteOrder) ? getBytes() : reverse(getBytes());
+        }
+
+        private static byte[] reverse(byte[] bytes) {
+            byte[] reversedBytes = new byte[bytes.length];
+            for (int i = 0; i < bytes.length; i++) {
+                reversedBytes[i] = bytes[bytes.length - i - 1];
+            }
+            return reversedBytes;
+        }
+    }
+
+    Bytes(byte[] bytes) {
+        mBytes = bytes;
+    }
+
+    private static String toHexString(byte[] bytes) {
+        StringBuilder sb = new StringBuilder(2 * bytes.length);
+        for (byte b : bytes) {
+            sb.append(sHexDigits[(b >> 4) & 0xf]).append(sHexDigits[b & 0xf]);
+        }
+        return sb.toString();
+    }
+
+    /** Returns 2-byte values in the same order, each using the given byte order. */
+    public static byte[] toBytes(ByteOrder byteOrder, short... shorts) {
+        ByteBuffer byteBuffer = ByteBuffer.allocate(shorts.length * 2).order(byteOrder);
+        for (short s : shorts) {
+            byteBuffer.putShort(s);
+        }
+        return byteBuffer.array();
+    }
+
+    /** Returns the shorts in the same order, each converted using the given byte order. */
+    static short[] toShorts(ByteOrder byteOrder, byte[] bytes) {
+        ShortBuffer shortBuffer = ByteBuffer.wrap(bytes).order(byteOrder).asShortBuffer();
+        short[] shorts = new short[shortBuffer.remaining()];
+        shortBuffer.get(shorts);
+        return shorts;
+    }
+
+    /** @return The bytes. */
+    public byte[] getBytes() {
+        return mBytes;
+    }
+
+    @Override
+    public boolean equals(@Nullable Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof Bytes)) {
+            return false;
+        }
+        Bytes that = (Bytes) o;
+        return Arrays.equals(mBytes, that.mBytes);
+    }
+
+    @Override
+    public int hashCode() {
+        return Arrays.hashCode(mBytes);
+    }
+
+    @Override
+    public String toString() {
+        return toHexString(mBytes);
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/FastPairConstants.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/FastPairConstants.java
new file mode 100644
index 0000000..0ff1bf2
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/FastPairConstants.java
@@ -0,0 +1,77 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+import android.bluetooth.BluetoothDevice;
+
+/** Constants to share with other team. */
+public class FastPairConstants {
+    private static final String PACKAGE_NAME = "com.android.server.nearby";
+    private static final String PREFIX = PACKAGE_NAME + ".common.bluetooth.fastpair.";
+
+    /** MODEL_ID item name for extended intent field. */
+    public static final String EXTRA_MODEL_ID = PREFIX + "MODEL_ID";
+    /** CONNECTION_ID item name for extended intent field. */
+    public static final String EXTRA_CONNECTION_ID = PREFIX + "CONNECTION_ID";
+    /** BLUETOOTH_MAC_ADDRESS item name for extended intent field. */
+    public static final String EXTRA_BLUETOOTH_MAC_ADDRESS = PREFIX + "BLUETOOTH_MAC_ADDRESS";
+    /** COMPANION_SCAN_ITEM item name for extended intent field. */
+    public static final String EXTRA_SCAN_ITEM = PREFIX + "COMPANION_SCAN_ITEM";
+    /** BOND_RESULT item name for extended intent field. */
+    public static final String EXTRA_BOND_RESULT = PREFIX + "EXTRA_BOND_RESULT";
+
+    /**
+     * The bond result of the {@link BluetoothDevice} when FastPair launches the companion app, it
+     * means device is BONDED but the pairing process is not triggered by FastPair.
+     */
+    public static final int BOND_RESULT_SUCCESS_WITHOUT_FP = 0;
+
+    /**
+     * The bond result of the {@link BluetoothDevice} when FastPair launches the companion app, it
+     * means device is BONDED and the pairing process is triggered by FastPair.
+     */
+    public static final int BOND_RESULT_SUCCESS_WITH_FP = 1;
+
+    /**
+     * The bond result of the {@link BluetoothDevice} when FastPair launches the companion app, it
+     * means the pairing process triggered by FastPair is failed due to the lack of PIN code.
+     */
+    public static final int BOND_RESULT_FAIL_WITH_FP_WITHOUT_PIN = 2;
+
+    /**
+     * The bond result of the {@link BluetoothDevice} when FastPair launches the companion app, it
+     * means the pairing process triggered by FastPair is failed due to the PIN code is not
+     * confirmed by the user.
+     */
+    public static final int BOND_RESULT_FAIL_WITH_FP_WITH_PIN_NOT_CONFIRMED = 3;
+
+    /**
+     * The bond result of the {@link BluetoothDevice} when FastPair launches the companion app, it
+     * means the pairing process triggered by FastPair is failed due to the user thinks the PIN is
+     * wrong.
+     */
+    public static final int BOND_RESULT_FAIL_WITH_FP_WITH_PIN_WRONG = 4;
+
+    /**
+     * The bond result of the {@link BluetoothDevice} when FastPair launches the companion app, it
+     * means the pairing process triggered by FastPair is failed even after the user confirmed the
+     * PIN code is correct.
+     */
+    public static final int BOND_RESULT_FAIL_WITH_FP_WITH_PIN_CORRECT = 5;
+
+    private FastPairConstants() {}
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/Ltv.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/Ltv.java
new file mode 100644
index 0000000..88c9484
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/Ltv.java
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+import static com.google.common.io.BaseEncoding.base16;
+
+import com.google.common.primitives.Bytes;
+import com.google.errorprone.annotations.FormatMethod;
+import com.google.errorprone.annotations.FormatString;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * A length, type, value (LTV) data block.
+ */
+public class Ltv {
+
+    private static final int SIZE_OF_LEN_TYPE = 2;
+
+    final byte mType;
+    final byte[] mValue;
+
+    /**
+     * Thrown if there's an error during {@link #parse}.
+     */
+    public static class ParseException extends Exception {
+
+        @FormatMethod
+        private ParseException(@FormatString String format, Object... objects) {
+            super(String.format(format, objects));
+        }
+    }
+
+    /**
+     * Constructor.
+     */
+    public Ltv(byte type, byte... value) {
+        this.mType = type;
+        this.mValue = value;
+    }
+
+    /**
+     * Parses a list of LTV blocks out of the input byte block.
+     */
+    static List<Ltv> parse(byte[] bytes) throws ParseException {
+        List<Ltv> ltvs = new ArrayList<>();
+        // The "+ 2" is for the length and type bytes.
+        for (int valueLength, i = 0; i < bytes.length; i += SIZE_OF_LEN_TYPE + valueLength) {
+            // - 1 since the length in the packet includes the type byte.
+            valueLength = bytes[i] - 1;
+            if (valueLength < 0 || bytes.length < i + SIZE_OF_LEN_TYPE + valueLength) {
+                throw new ParseException(
+                        "Wrong length=%d at index=%d in LTVs=%s", bytes[i], i,
+                        base16().encode(bytes));
+            }
+            ltvs.add(new Ltv(bytes[i + 1], Arrays.copyOfRange(bytes, i + SIZE_OF_LEN_TYPE,
+                    i + SIZE_OF_LEN_TYPE + valueLength)));
+        }
+        return ltvs;
+    }
+
+    /**
+     * Returns an LTV block, where length is mValue.length + 1 (for the type byte).
+     */
+    public byte[] getBytes() {
+        return Bytes.concat(new byte[]{(byte) (mValue.length + 1), mType}, mValue);
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/PairingException.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/PairingException.java
new file mode 100644
index 0000000..722dc85
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/PairingException.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+/** Base class for pairing exceptions. */
+// TODO(b/200594968): convert exceptions into error codes to save memory.
+public class PairingException extends Exception {
+    PairingException(String format, Object... objects) {
+        super(String.format(format, objects));
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/PairingProgressListener.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/PairingProgressListener.java
new file mode 100644
index 0000000..8f8e498
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/PairingProgressListener.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+/** Callback interface for pairing progress. */
+public interface PairingProgressListener {
+    /** Enum for pairing events. */
+    enum PairingEvent {
+        START,
+        SUCCESS,
+        FAILED,
+        UNKNOWN;
+
+        public static PairingEvent fromOrdinal(int ordinal) {
+            PairingEvent[] values = PairingEvent.values();
+            if (ordinal < 0 || ordinal >= values.length) {
+                return UNKNOWN;
+            }
+            return values[ordinal];
+        }
+    }
+
+    /** Callback function upon pairing progress update. */
+    void onPairingProgressUpdating(PairingEvent event, String message);
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/PasskeyConfirmationHandler.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/PasskeyConfirmationHandler.java
new file mode 100644
index 0000000..f5807a3
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/PasskeyConfirmationHandler.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+import android.bluetooth.BluetoothDevice;
+
+/** Interface for getting the passkey confirmation request. */
+public interface PasskeyConfirmationHandler {
+    /** Called when getting the passkey confirmation request while pairing. */
+    void onPasskeyConfirmation(BluetoothDevice device, int passkey);
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/SignalLostException.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/SignalLostException.java
new file mode 100644
index 0000000..244ee66
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/SignalLostException.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+/** Base class for fast pair signal lost exceptions. */
+public class SignalLostException extends PairingException {
+    SignalLostException(String message, Exception e) {
+        super(message);
+        initCause(e);
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/SignalRotatedException.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/SignalRotatedException.java
new file mode 100644
index 0000000..d0d2a5d
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/SignalRotatedException.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+/** Base class for fast pair signal rotated exceptions. */
+public class SignalRotatedException extends PairingException {
+    private final String mNewAddress;
+
+    SignalRotatedException(String message, String newAddress, Exception e) {
+        super(message);
+        this.mNewAddress = newAddress;
+        initCause(e);
+    }
+
+    /** Returns the new BLE address for the model ID. */
+    public String getNewAddress() {
+        return mNewAddress;
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/ToggleBluetoothTask.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/ToggleBluetoothTask.java
new file mode 100644
index 0000000..41ac9f5
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/ToggleBluetoothTask.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeoutException;
+
+/** Task for toggling Bluetooth on and back off again. */
+interface ToggleBluetoothTask {
+
+    /**
+     * Toggles the bluetooth adapter off and back on again to help improve connection reliability.
+     *
+     * @throws InterruptedException when waiting for the bluetooth adapter's state to be set has
+     *     been interrupted.
+     * @throws ExecutionException when waiting for the bluetooth adapter's state to be set has
+     *     failed.
+     * @throws TimeoutException when the bluetooth adapter's state fails to be set on or off.
+     */
+    void toggleBluetooth() throws InterruptedException, ExecutionException, TimeoutException;
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/testability/TimeProvider.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/testability/TimeProvider.java
new file mode 100644
index 0000000..a4de913
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/testability/TimeProvider.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.testability;
+
+/** Provider of time for testability. */
+public class TimeProvider {
+    public long getTimeMillis() {
+        return System.currentTimeMillis();
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/testability/VersionProvider.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/testability/VersionProvider.java
new file mode 100644
index 0000000..f46ea7a
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/testability/VersionProvider.java
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.testability;
+
+import android.os.Build.VERSION;
+
+/**
+ * Provider of android sdk version for testability
+ */
+public class VersionProvider {
+    public int getSdkInt() {
+        return VERSION.SDK_INT;
+    }
+}
diff --git a/nearby/tests/Android.bp b/nearby/tests/Android.bp
index 67a3b83..76b3683 100644
--- a/nearby/tests/Android.bp
+++ b/nearby/tests/Android.bp
@@ -35,6 +35,7 @@
         "androidx.test.rules",
         "framework-nearby-pre-jarjar",
         "platform-test-annotations",
+        "service-nearby",
         "truth-prebuilt",
     ],
     test_suites: [
diff --git a/nearby/tests/src/com/android/server/nearby/common/bluetooth/fastpair/AesEcbSingleBlockEncryptionTest.java b/nearby/tests/src/com/android/server/nearby/common/bluetooth/fastpair/AesEcbSingleBlockEncryptionTest.java
new file mode 100644
index 0000000..0e13133
--- /dev/null
+++ b/nearby/tests/src/com/android/server/nearby/common/bluetooth/fastpair/AesEcbSingleBlockEncryptionTest.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+import static com.google.common.io.BaseEncoding.base16;
+import static com.google.common.truth.Truth.assertThat;
+
+import android.platform.test.annotations.Presubmit;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import com.google.common.primitives.Bytes;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit tests for {@link AesEcbSingleBlockEncryption}. */
+@Presubmit
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public class AesEcbSingleBlockEncryptionTest {
+
+    private static final byte[] PLAINTEXT = base16().decode("F30F4E786C59A7BBF3873B5A49BA97EA");
+
+    @Test
+    public void encryptDecryptSuccessful() throws Exception {
+        byte[] secret = AesEcbSingleBlockEncryption.generateKey();
+        byte[] encrypted = AesEcbSingleBlockEncryption.encrypt(secret, PLAINTEXT);
+        assertThat(encrypted).isNotEqualTo(PLAINTEXT);
+        byte[] decrypted = AesEcbSingleBlockEncryption.decrypt(secret, encrypted);
+        assertThat(decrypted).isEqualTo(PLAINTEXT);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void encryptionSizeLimitationEnforced() throws Exception {
+        byte[] secret = AesEcbSingleBlockEncryption.generateKey();
+        byte[] largePacket = Bytes.concat(PLAINTEXT, PLAINTEXT);
+        AesEcbSingleBlockEncryption.encrypt(secret, largePacket);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void decryptionSizeLimitationEnforced() throws Exception {
+        byte[] secret = AesEcbSingleBlockEncryption.generateKey();
+        byte[] largePacket = Bytes.concat(PLAINTEXT, PLAINTEXT);
+        AesEcbSingleBlockEncryption.decrypt(secret, largePacket);
+    }
+}
diff --git a/nearby/tests/src/com/android/server/nearby/common/bluetooth/fastpair/BluetoothAddressTest.java b/nearby/tests/src/com/android/server/nearby/common/bluetooth/fastpair/BluetoothAddressTest.java
new file mode 100644
index 0000000..36ebb7e
--- /dev/null
+++ b/nearby/tests/src/com/android/server/nearby/common/bluetooth/fastpair/BluetoothAddressTest.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+package com.android.server.nearby.common.bluetooth.fastpair;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.bluetooth.BluetoothAdapter;
+import android.platform.test.annotations.Presubmit;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit tests for {@link BluetoothAddress}. */
+@Presubmit
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public class BluetoothAddressTest {
+
+    @Test
+    public void maskBluetoothAddress_whenInputIsNull() {
+        assertThat(BluetoothAddress.maskBluetoothAddress(null)).isEqualTo("");
+    }
+
+    @Test
+    public void maskBluetoothAddress_whenInputStringNotMatchFormat() {
+        assertThat(BluetoothAddress.maskBluetoothAddress("AA:BB:CC")).isEqualTo("AA:BB:CC");
+    }
+
+    @Test
+    public void maskBluetoothAddress_whenInputStringMatchFormat() {
+        assertThat(BluetoothAddress.maskBluetoothAddress("AA:BB:CC:DD:EE:FF"))
+                .isEqualTo("XX:XX:XX:XX:EE:FF");
+    }
+
+    @Test
+    public void maskBluetoothAddress_whenInputStringContainLowerCaseMatchFormat() {
+        assertThat(BluetoothAddress.maskBluetoothAddress("Aa:Bb:cC:dD:eE:Ff"))
+                .isEqualTo("XX:XX:XX:XX:EE:FF");
+    }
+
+    @Test
+    public void maskBluetoothAddress_whenInputBluetoothDevice() {
+        assertThat(
+                BluetoothAddress.maskBluetoothAddress(
+                        BluetoothAdapter.getDefaultAdapter().getRemoteDevice("FF:EE:DD:CC:BB:AA")))
+                .isEqualTo("XX:XX:XX:XX:BB:AA");
+    }
+}