Expose IMSI encryption info APIs as system API

Bug: 142431997
Test: make
Change-Id: I7bd15f225ac7774ac6e31c766ee0f11302aae3d8

api/system-current.txt

@@ -7860,6 +7860,14 @@ package android.telephony {
     field public static final int WIFI_LOST = 59; // 0x3b
   }
 
+  public final class ImsiEncryptionInfo implements android.os.Parcelable {
+    method public int describeContents();
+    method @Nullable public String getKeyIdentifier();
+    method @Nullable public java.security.PublicKey getPublicKey();
+    method public void writeToParcel(@NonNull android.os.Parcel, int);
+    field @NonNull public static final android.os.Parcelable.Creator<android.telephony.ImsiEncryptionInfo> CREATOR;
+  }
+
   public final class LteVopsSupportInfo implements android.os.Parcelable {
     ctor public LteVopsSupportInfo(int, int);
     method public int describeContents();
@@ -8343,6 +8351,7 @@ package android.telephony {
     method @Deprecated @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void enableVideoCalling(boolean);
     method @Nullable @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE) public String getAidForAppType(int);
     method @Deprecated @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE) public java.util.List<android.service.carrier.CarrierIdentifier> getAllowedCarriers(int);
+    method @Nullable @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE) public android.telephony.ImsiEncryptionInfo getCarrierInfoForImsiEncryption(int);
     method public java.util.List<java.lang.String> getCarrierPackageNamesForIntent(android.content.Intent);
     method public java.util.List<java.lang.String> getCarrierPackageNamesForIntentAndPhone(android.content.Intent, int);
     method @Nullable @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE) public android.telephony.CarrierRestrictionRules getCarrierRestrictionRules();
@@ -8396,6 +8405,7 @@ package android.telephony {
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public boolean rebootRadio();
     method @RequiresPermission(allOf={android.Manifest.permission.ACCESS_FINE_LOCATION, android.Manifest.permission.MODIFY_PHONE_STATE}) public void requestCellInfoUpdate(@NonNull android.os.WorkSource, @NonNull java.util.concurrent.Executor, @NonNull android.telephony.TelephonyManager.CellInfoCallback);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void requestNumberVerification(@NonNull android.telephony.PhoneNumberRange, long, @NonNull java.util.concurrent.Executor, @NonNull android.telephony.NumberVerificationCallback);
+    method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void resetCarrierKeysForImsiEncryption();
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public boolean resetRadioConfig();
     method @Deprecated @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public int setAllowedCarriers(int, java.util.List<android.service.carrier.CarrierIdentifier>);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setCarrierDataEnabled(boolean);
@@ -8431,6 +8441,8 @@ package android.telephony {
     field public static final String EXTRA_SIM_STATE = "android.telephony.extra.SIM_STATE";
     field public static final String EXTRA_VISUAL_VOICEMAIL_ENABLED_BY_USER_BOOL = "android.telephony.extra.VISUAL_VOICEMAIL_ENABLED_BY_USER_BOOL";
     field public static final String EXTRA_VOICEMAIL_SCRAMBLED_PIN_STRING = "android.telephony.extra.VOICEMAIL_SCRAMBLED_PIN_STRING";
+    field public static final int KEY_TYPE_EPDG = 1; // 0x1
+    field public static final int KEY_TYPE_WLAN = 2; // 0x2
     field public static final long NETWORK_TYPE_BITMASK_1xRTT = 64L; // 0x40L
     field public static final long NETWORK_TYPE_BITMASK_CDMA = 8L; // 0x8L
     field public static final long NETWORK_TYPE_BITMASK_EDGE = 2L; // 0x2L

telephony/java/android/telephony/ImsiEncryptionInfo.java

@@ -15,9 +15,11 @@
  */
 package android.telephony;
 
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.SystemApi;
 import android.os.Parcel;
 import android.os.Parcelable;
-import java.util.Date;
 import android.util.Log;
 
 import java.security.KeyFactory;
@@ -25,18 +27,18 @@ import java.security.NoSuchAlgorithmException;
 import java.security.PublicKey;
 import java.security.spec.InvalidKeySpecException;
 import java.security.spec.X509EncodedKeySpec;
+import java.util.Date;
 
 /**
  * Class to represent information sent by the carrier, which will be used to encrypt
  * the IMSI + IMPI. The ecryption is being done by WLAN, and the modem.
- *
  * @hide
  */
+@SystemApi
 public final class ImsiEncryptionInfo implements Parcelable {
 
     private static final String LOG_TAG = "ImsiEncryptionInfo";
 
-
     private final String mcc;
     private final String mnc;
     private final PublicKey publicKey;
@@ -45,11 +47,13 @@ public final class ImsiEncryptionInfo implements Parcelable {
     //Date-Time in UTC when the key will expire.
     private final Date expirationTime;
 
+    /** @hide */
     public ImsiEncryptionInfo(String mcc, String mnc, int keyType, String keyIdentifier,
                               byte[] key, Date expirationTime) {
         this(mcc, mnc, keyType, keyIdentifier, makeKeyObject(key), expirationTime);
     }
 
+    /** @hide */
     public ImsiEncryptionInfo(String mcc, String mnc, int keyType, String keyIdentifier,
                               PublicKey publicKey, Date expirationTime) {
         // todo need to validate that ImsiEncryptionInfo is being created with the correct params.
@@ -63,6 +67,7 @@ public final class ImsiEncryptionInfo implements Parcelable {
         this.expirationTime = expirationTime;
     }
 
+    /** @hide */
     public ImsiEncryptionInfo(Parcel in) {
         int length = in.readInt();
         byte b[] = new byte[length];
@@ -75,26 +80,40 @@ public final class ImsiEncryptionInfo implements Parcelable {
         expirationTime = new Date(in.readLong());
     }
 
+    /** @hide */
     public String getMnc() {
         return this.mnc;
     }
 
+    /** @hide */
     public String getMcc() {
         return this.mcc;
     }
 
+    /**
+     * Returns key identifier, a string that helps the authentication server to locate the
+     * private key to decrypt the permanent identity, or {@code null} when uavailable.
+     */
+    @Nullable
     public String getKeyIdentifier() {
         return this.keyIdentifier;
     }
 
+    /** @hide */
     public int getKeyType() {
         return this.keyType;
     }
 
+    /**
+     * Returns the carrier public key that is used for the IMSI encryption,
+     * or {@code null} when uavailable.
+     */
+    @Nullable
     public PublicKey getPublicKey() {
         return this.publicKey;
     }
 
+    /** @hide */
     public Date getExpirationTime() {
         return this.expirationTime;
     }
@@ -115,7 +134,7 @@ public final class ImsiEncryptionInfo implements Parcelable {
         return 0;
     }
 
-    public static final @android.annotation.NonNull Parcelable.Creator<ImsiEncryptionInfo> CREATOR =
+    public static final @NonNull Parcelable.Creator<ImsiEncryptionInfo> CREATOR =
             new Parcelable.Creator<ImsiEncryptionInfo>() {
                 @Override
                 public ImsiEncryptionInfo createFromParcel(Parcel in) {
@@ -129,7 +148,7 @@ public final class ImsiEncryptionInfo implements Parcelable {
             };
 
     @Override
-    public void writeToParcel(Parcel dest, int flags) {
+    public void writeToParcel(@NonNull Parcel dest, int flags) {
         byte[] b = publicKey.getEncoded();
         dest.writeInt(b.length);
         dest.writeByteArray(b);

telephony/java/android/telephony/TelephonyManager.java

@@ -197,12 +197,29 @@ public class TelephonyManager {
     /** @hide */
     static public final int OTASP_SIM_UNPROVISIONED = 5;
 
-    /** @hide */
+    /**
+     * Used in carrier Wi-Fi for IMSI + IMPI encryption, this indicates a public key that's
+     * available for use in ePDG links.
+     *
+     * @hide
+     */
+    @SystemApi
     static public final int KEY_TYPE_EPDG = 1;
 
-    /** @hide */
+    /**
+     * Used in carrier Wi-Fi for IMSI + IMPI encryption, this indicates a public key that's
+     * available for use in WLAN links.
+     *
+     * @hide
+     */
+    @SystemApi
     static public final int KEY_TYPE_WLAN = 2;
 
+    /** @hide */
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef(prefix = {"KEY_TYPE_"}, value = {KEY_TYPE_EPDG, KEY_TYPE_WLAN})
+    public @interface KeyType {}
+
     /**
      * No Single Radio Voice Call Continuity (SRVCC) handover is active.
      * See TS 23.216 for more information.
@@ -3869,25 +3886,27 @@ public class TelephonyManager {
     }
 
     /**
-     * Returns Carrier specific information that will be used to encrypt the IMSI and IMPI.
+     * Returns carrier specific information that will be used to encrypt the IMSI and IMPI,
-     * This includes the public key and the key identifier. For multi-sim devices, if no subId
+     * including the public key and the key identifier; or {@code null} if not available.
-     * has been specified, we will return the value for the dafault data sim.
-     * Return null if it is unavailable.
      * <p>
-     * Requires Permission:
+     * For a multi-sim device, the dafault data sim is used if not specified.
-     *   {@link android.Manifest.permission#READ_PHONE_STATE READ_PHONE_STATE}
+     * <p>
-     * @param keyType whether the key is being used for wlan or epdg. Valid key types are
+     * Requires Permission: READ_PRIVILEGED_PHONE_STATE.
-     *        {@link TelephonyManager#KEY_TYPE_EPDG} or
+     *
-     *        {@link TelephonyManager#KEY_TYPE_WLAN}.
+     * @param keyType whether the key is being used for EPDG or WLAN. Valid values are
+     *        {@link #KEY_TYPE_EPDG} or {@link #KEY_TYPE_WLAN}.
      * @return ImsiEncryptionInfo Carrier specific information that will be used to encrypt the
      *         IMSI and IMPI. This includes the public key and the key identifier. This information
-     *         will be stored in the device keystore. The system will return a null when no key was
+     *         will be stored in the device keystore. {@code null} will be returned when no key is
-     *         found, and the carrier does not require a key. The system will throw
+     *         found, and the carrier does not require a key.
-     *         IllegalArgumentException when an invalid key is sent or when key is required but
+     * @throws IllegalArgumentException when an invalid key is found or when key is required but
      *         not found.
      * @hide
      */
-    public ImsiEncryptionInfo getCarrierInfoForImsiEncryption(int keyType) {
+    @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE)
+    @SystemApi
+    @Nullable
+    public ImsiEncryptionInfo getCarrierInfoForImsiEncryption(@KeyType int keyType) {
         try {
             IPhoneSubInfo info = getSubscriberInfo();
             if (info == null) {
@@ -3915,14 +3934,21 @@ public class TelephonyManager {
     }
 
     /**
-     * Resets the Carrier Keys in the database. This involves 2 steps:
+     * Resets the carrier keys used to encrypt the IMSI and IMPI.
+     * <p>
+     * This involves 2 steps:
      *  1. Delete the keys from the database.
      *  2. Send an intent to download new Certificates.
      * <p>
-     * Requires Permission:
+     * For a multi-sim device, the dafault data sim is used if not specified.
-     *   {@link android.Manifest.permission#MODIFY_PHONE_STATE MODIFY_PHONE_STATE}
+     * <p>
+     * Requires Permission: MODIFY_PHONE_STATE.
+     *
+     * @see #getCarrierInfoForImsiEncryption
      * @hide
      */
+    @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE)
+    @SystemApi
     public void resetCarrierKeysForImsiEncryption() {
         try {
             IPhoneSubInfo info = getSubscriberInfo();
@@ -3949,7 +3975,7 @@ public class TelephonyManager {
      * @return true if the digit at position keyType is 1, else false.
      * @hide
      */
-    private static boolean isKeyEnabled(int keyAvailability, int keyType) {
+    private static boolean isKeyEnabled(int keyAvailability, @KeyType int keyType) {
         int returnValue = (keyAvailability >> (keyType - 1)) & 1;
         return (returnValue == 1) ? true : false;
     }
@@ -3958,7 +3984,7 @@ public class TelephonyManager {
      * If Carrier requires Imsi to be encrypted.
      * @hide
      */
-    private boolean isImsiEncryptionRequired(int subId, int keyType) {
+    private boolean isImsiEncryptionRequired(int subId, @KeyType int keyType) {
         CarrierConfigManager configManager =
                 (CarrierConfigManager) mContext.getSystemService(Context.CARRIER_CONFIG_SERVICE);
         if (configManager == null) {