diff --git a/core/java/android/net/IpSecAlgorithm.java b/core/java/android/net/IpSecAlgorithm.java
index 57f05884ce6d5..8034bb62c94c6 100644
--- a/core/java/android/net/IpSecAlgorithm.java
+++ b/core/java/android/net/IpSecAlgorithm.java
@@ -56,7 +56,8 @@ public final class IpSecAlgorithm implements Parcelable {
      * new applications and is provided for legacy compatibility with 3gpp infrastructure.</b>
      *
      * <p>Keys for this algorithm must be 128 bits in length.
-     * <p>Valid truncation lengths are multiples of 8 bits from 96 to (default) 128.
+     *
+     * <p>Valid truncation lengths are multiples of 8 bits from 96 to 128.
      */
     public static final String AUTH_HMAC_MD5 = "hmac(md5)";
 
@@ -65,7 +66,8 @@ public final class IpSecAlgorithm implements Parcelable {
      * new applications and is provided for legacy compatibility with 3gpp infrastructure.</b>
      *
      * <p>Keys for this algorithm must be 160 bits in length.
-     * <p>Valid truncation lengths are multiples of 8 bits from 96 to (default) 160.
+     *
+     * <p>Valid truncation lengths are multiples of 8 bits from 96 to 160.
      */
     public static final String AUTH_HMAC_SHA1 = "hmac(sha1)";
 
@@ -73,7 +75,8 @@ public final class IpSecAlgorithm implements Parcelable {
      * SHA256 HMAC Authentication/Integrity Algorithm.
      *
      * <p>Keys for this algorithm must be 256 bits in length.
-     * <p>Valid truncation lengths are multiples of 8 bits from 96 to (default) 256.
+     *
+     * <p>Valid truncation lengths are multiples of 8 bits from 96 to 256.
      */
     public static final String AUTH_HMAC_SHA256 = "hmac(sha256)";
 
@@ -81,7 +84,8 @@ public final class IpSecAlgorithm implements Parcelable {
      * SHA384 HMAC Authentication/Integrity Algorithm.
      *
      * <p>Keys for this algorithm must be 384 bits in length.
-     * <p>Valid truncation lengths are multiples of 8 bits from 192 to (default) 384.
+     *
+     * <p>Valid truncation lengths are multiples of 8 bits from 192 to 384.
      */
     public static final String AUTH_HMAC_SHA384 = "hmac(sha384)";
 
@@ -89,7 +93,8 @@ public final class IpSecAlgorithm implements Parcelable {
      * SHA512 HMAC Authentication/Integrity Algorithm.
      *
      * <p>Keys for this algorithm must be 512 bits in length.
-     * <p>Valid truncation lengths are multiples of 8 bits from 256 to (default) 512.
+     *
+     * <p>Valid truncation lengths are multiples of 8 bits from 256 to 512.
      */
     public static final String AUTH_HMAC_SHA512 = "hmac(sha512)";
 
@@ -112,6 +117,7 @@ public final class IpSecAlgorithm implements Parcelable {
         AUTH_HMAC_MD5,
         AUTH_HMAC_SHA1,
         AUTH_HMAC_SHA256,
+        AUTH_HMAC_SHA384,
         AUTH_HMAC_SHA512,
         AUTH_CRYPT_AES_GCM
     })
@@ -126,11 +132,14 @@ public final class IpSecAlgorithm implements Parcelable {
      * Creates an IpSecAlgorithm of one of the supported types. Supported algorithm names are
      * defined as constants in this class.
      *
+     * <p>For algorithms that produce an integrity check value, the truncation length is a required
+     * parameter. See {@link #IpSecAlgorithm(String algorithm, byte[] key, int truncLenBits)}
+     *
      * @param algorithm name of the algorithm.
      * @param key key padded to a multiple of 8 bits.
      */
     public IpSecAlgorithm(@NonNull @AlgorithmName String algorithm, @NonNull byte[] key) {
-        this(algorithm, key, key.length * 8);
+        this(algorithm, key, 0);
     }
 
     /**
@@ -228,6 +237,7 @@ public final class IpSecAlgorithm implements Parcelable {
             case AUTH_CRYPT_AES_GCM:
                 // The keying material for GCM is a key plus a 32-bit salt
                 isValidLen = keyLen == 128 + 32 || keyLen == 192 + 32 || keyLen == 256 + 32;
+                isValidTruncLen = truncLen == 64 || truncLen == 96 || truncLen == 128;
                 break;
             default:
                 throw new IllegalArgumentException("Couldn't find an algorithm: " + name);
diff --git a/tests/net/java/android/net/IpSecAlgorithmTest.java b/tests/net/java/android/net/IpSecAlgorithmTest.java
index 6bdfdc6db2d1c..85e836179b5ea 100644
--- a/tests/net/java/android/net/IpSecAlgorithmTest.java
+++ b/tests/net/java/android/net/IpSecAlgorithmTest.java
@@ -22,8 +22,12 @@ import static org.junit.Assert.fail;
 import android.os.Parcel;
 import android.support.test.filters.SmallTest;
 import android.support.test.runner.AndroidJUnit4;
+
+import java.util.AbstractMap.SimpleEntry;
 import java.util.Arrays;
+import java.util.Map.Entry;
 import java.util.Random;
+
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
@@ -40,19 +44,29 @@ public class IpSecAlgorithmTest {
     };
 
     @Test
-    public void testDefaultTruncLen() throws Exception {
-        IpSecAlgorithm explicit =
+    public void testNoTruncLen() throws Exception {
+        Entry<String, Integer>[] authAndAeadList =
+                new Entry[] {
+                    new SimpleEntry<>(IpSecAlgorithm.AUTH_HMAC_MD5, 128),
+                    new SimpleEntry<>(IpSecAlgorithm.AUTH_HMAC_SHA1, 160),
+                    new SimpleEntry<>(IpSecAlgorithm.AUTH_HMAC_SHA256, 256),
+                    new SimpleEntry<>(IpSecAlgorithm.AUTH_HMAC_SHA384, 384),
+                    new SimpleEntry<>(IpSecAlgorithm.AUTH_HMAC_SHA512, 512),
+                    new SimpleEntry<>(IpSecAlgorithm.AUTH_CRYPT_AES_GCM, 224)
+                };
+
+        // Expect auth and aead algorithms to throw errors if trunclen is omitted.
+        for (Entry<String, Integer> algData : authAndAeadList) {
+            try {
                 new IpSecAlgorithm(
-                        IpSecAlgorithm.AUTH_HMAC_SHA256, Arrays.copyOf(KEY_MATERIAL, 256 / 8), 256);
-        IpSecAlgorithm implicit =
-                new IpSecAlgorithm(
-                        IpSecAlgorithm.AUTH_HMAC_SHA256, Arrays.copyOf(KEY_MATERIAL, 256 / 8));
-        assertTrue(
-                "Default Truncation Length Incorrect, Explicit: "
-                        + explicit
-                        + "implicit: "
-                        + implicit,
-                IpSecAlgorithm.equals(explicit, implicit));
+                        algData.getKey(), Arrays.copyOf(KEY_MATERIAL, algData.getValue() / 8));
+                fail("Expected exception on unprovided auth trunclen");
+            } catch (IllegalArgumentException expected) {
+            }
+        }
+
+        // Ensure crypt works with no truncation length supplied.
+        new IpSecAlgorithm(IpSecAlgorithm.CRYPT_AES_CBC, Arrays.copyOf(KEY_MATERIAL, 256 / 8));
     }
 
     @Test
diff --git a/tests/net/java/android/net/IpSecConfigTest.java b/tests/net/java/android/net/IpSecConfigTest.java
index f186ee55d2c7d..771faaf4955d2 100644
--- a/tests/net/java/android/net/IpSecConfigTest.java
+++ b/tests/net/java/android/net/IpSecConfigTest.java
@@ -62,7 +62,8 @@ public class IpSecConfigTest {
         c.setAuthentication(
                 new IpSecAlgorithm(
                         IpSecAlgorithm.AUTH_HMAC_MD5,
-                        new byte[] {1, 2, 3, 4, 5, 6, 7, 8, 9, 0xA, 0xB, 0xC, 0xD, 0xE, 0xF, 0}));
+                        new byte[] {1, 2, 3, 4, 5, 6, 7, 8, 9, 0xA, 0xB, 0xC, 0xD, 0xE, 0xF, 0},
+                        128));
         c.setAuthenticatedEncryption(
                 new IpSecAlgorithm(
                         IpSecAlgorithm.AUTH_CRYPT_AES_GCM,