nfc-non-updatable/java/android/nfc/cardemulation/AidGroup.java - platform/frameworks/base - Git at Google

 /*
  * 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.
  */

 package android.nfc.cardemulation;

 import android.annotation.FlaggedApi;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.nfc.Flags;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.util.Log;
 import android.util.proto.ProtoOutputStream;

 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;
 import org.xmlpull.v1.XmlSerializer;

 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;
 import java.util.regex.Pattern;

 /**********************************************************************
  * This file is not a part of the NFC mainline module                 *
  * *******************************************************************/

 /**
  * The AidGroup class represents a group of Application Identifiers (AIDs).
  *
  * <p>The format of AIDs is defined in the ISO/IEC 7816-4 specification. This class
  * requires the AIDs to be input as a hexadecimal string, with an even amount of
  * hexadecimal characters, e.g. "F014811481".
  *
  * @hide
  */
 @SystemApi
 @FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
 public final class AidGroup implements Parcelable {
     /**
      * The maximum number of AIDs that can be present in any one group.
      */
     private static final int MAX_NUM_AIDS = 256;

     private static final String TAG = "AidGroup";


     private final List<String> mAids;
     private final String mCategory;
     @SuppressWarnings("unused") // Unused as of now, but part of the XML input.
     private final String mDescription;

     /**
      * Creates a new AidGroup object.
      *
      * @param aids list of AIDs present in the group
      * @param category category of this group, e.g. {@link CardEmulation#CATEGORY_PAYMENT}
      */
     @FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
     public AidGroup(@NonNull List<String> aids, @Nullable String category) {
         if (aids == null || aids.size() == 0) {
             throw new IllegalArgumentException("No AIDS in AID group.");
         }
         if (aids.size() > MAX_NUM_AIDS) {
             throw new IllegalArgumentException("Too many AIDs in AID group.");
         }
         for (String aid : aids) {
             if (!isValidAid(aid)) {
                 throw new IllegalArgumentException("AID " + aid + " is not a valid AID.");
             }
         }
         if (isValidCategory(category)) {
             this.mCategory = category;
         } else {
             this.mCategory = CardEmulation.CATEGORY_OTHER;
         }
         this.mAids = new ArrayList<String>(aids.size());
         for (String aid : aids) {
             this.mAids.add(aid.toUpperCase(Locale.US));
         }
         this.mDescription = null;
     }

     /**
      * Creates a new AidGroup object.
      *
      * @param category category of this group, e.g. {@link CardEmulation#CATEGORY_PAYMENT}
      * @param description description of this group
      */
     AidGroup(@NonNull String category, @NonNull String description) {
         this.mAids = new ArrayList<String>();
         this.mCategory = category;
         this.mDescription = description;
     }

     /**
      * Returns the category of this group.
      * @return the category of this AID group
      */
     @FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
     @NonNull
     public String getCategory() {
         return mCategory;
     }

     /**
      * Returns the list of AIDs in this group.
      *
      * @return the list of AIDs in this group
      */
     @FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
     @NonNull
     public List<String> getAids() {
         return mAids;
     }

     @Override
     public String toString() {
         StringBuilder out = new StringBuilder("Category: " + mCategory
                 + ", AIDs:");
         for (String aid : mAids) {
             out.append(aid);
             out.append(", ");
         }
         return out.toString();
     }

     /**
      * Dump debugging info as AidGroupProto.
      *
      * If the output belongs to a sub message, the caller is responsible for wrapping this function
      * between {@link ProtoOutputStream#start(long)} and {@link ProtoOutputStream#end(long)}.
      *
      * @param proto the ProtoOutputStream to write to
      */
     @FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
     public void dump(@NonNull ProtoOutputStream proto) {
         proto.write(AidGroupProto.CATEGORY, mCategory);
         for (String aid : mAids) {
             proto.write(AidGroupProto.AIDS, aid);
         }
     }

     @FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
     @Override
     public int describeContents() {
         return 0;
     }

     @FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
     @Override
     public void writeToParcel(@NonNull Parcel dest, int flags) {
         dest.writeString8(mCategory);
         dest.writeInt(mAids.size());
         if (mAids.size() > 0) {
             dest.writeStringList(mAids);
         }
     }

     @FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
     public static final @NonNull Parcelable.Creator<AidGroup> CREATOR =
             new Parcelable.Creator<AidGroup>() {

         @Override
         public AidGroup createFromParcel(Parcel source) {
             String category = source.readString8();
             int listSize = source.readInt();
             ArrayList<String> aidList = new ArrayList<String>();
             if (listSize > 0) {
                 source.readStringList(aidList);
             }
             return new AidGroup(aidList, category);
         }

         @Override
         public AidGroup[] newArray(int size) {
             return new AidGroup[size];
         }
     };

     /**
      * Create an instance of AID group from XML file.
      *
      * @param parser input xml parser stream
      * @throws XmlPullParserException If an error occurs parsing the element.
      * @throws IOException If an error occurs reading the element.
      */
     @FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
     @Nullable
     public static AidGroup createFromXml(@NonNull XmlPullParser parser)
             throws XmlPullParserException, IOException {
         String category = null;
         ArrayList<String> aids = new ArrayList<String>();
         AidGroup group = null;
         boolean inGroup = false;

         int eventType = parser.getEventType();
         int minDepth = parser.getDepth();
         while (eventType != XmlPullParser.END_DOCUMENT && parser.getDepth() >= minDepth) {
             String tagName = parser.getName();
             if (eventType == XmlPullParser.START_TAG) {
                 if (tagName.equals("aid")) {
                     if (inGroup) {
                         String aid = parser.getAttributeValue(null, "value");
                         if (aid != null) {
                             aids.add(aid.toUpperCase());
                         }
                     } else {
                         Log.d(TAG, "Ignoring <aid> tag while not in group");
                     }
                 } else if (tagName.equals("aid-group")) {
                     category = parser.getAttributeValue(null, "category");
                     if (category == null) {
                         Log.e(TAG, "<aid-group> tag without valid category");
                         return null;
                     }
                     inGroup = true;
                 } else {
                     Log.d(TAG, "Ignoring unexpected tag: " + tagName);
                 }
             } else if (eventType == XmlPullParser.END_TAG) {
                 if (tagName.equals("aid-group") && inGroup && aids.size() > 0) {
                     group = new AidGroup(aids, category);
                     break;
                 }
             }
             eventType = parser.next();
         }
         return group;
     }

     /**
      * Serialize instance of AID group to XML file.
      * @param out XML serializer stream
      * @throws IOException If an error occurs reading the element.
      */
     @FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
     public void writeAsXml(@NonNull XmlSerializer out) throws IOException {
         out.startTag(null, "aid-group");
         out.attribute(null, "category", mCategory);
         for (String aid : mAids) {
             out.startTag(null, "aid");
             out.attribute(null, "value", aid);
             out.endTag(null, "aid");
         }
         out.endTag(null, "aid-group");
     }

     private static boolean isValidCategory(String category) {
         return CardEmulation.CATEGORY_PAYMENT.equals(category) ||
                 CardEmulation.CATEGORY_OTHER.equals(category);
     }

     private static final Pattern AID_PATTERN = Pattern.compile("[0-9A-Fa-f]{10,32}\\*?\\#?");
     /**
      * Copied over from {@link CardEmulation#isValidAid(String)}
      * @hide
      */
     private static boolean isValidAid(String aid) {
         if (aid == null)
             return false;

         // If a prefix/subset AID, the total length must be odd (even # of AID chars + '*')
         if ((aid.endsWith("*") || aid.endsWith("#")) && ((aid.length() % 2) == 0)) {
             Log.e(TAG, "AID " + aid + " is not a valid AID.");
             return false;
         }

         // If not a prefix/subset AID, the total length must be even (even # of AID chars)
         if ((!(aid.endsWith("*") || aid.endsWith("#"))) && ((aid.length() % 2) != 0)) {
             Log.e(TAG, "AID " + aid + " is not a valid AID.");
             return false;
         }

         // Verify hex characters
         if (!AID_PATTERN.matcher(aid).matches()) {
             Log.e(TAG, "AID " + aid + " is not a valid AID.");
             return false;
         }

         return true;
     }
 }
	/*
	* 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.
	*/

	package android.nfc.cardemulation;

	import android.annotation.FlaggedApi;
	import android.annotation.NonNull;
	import android.annotation.Nullable;
	import android.annotation.SystemApi;
	import android.nfc.Flags;
	import android.os.Parcel;
	import android.os.Parcelable;
	import android.util.Log;
	import android.util.proto.ProtoOutputStream;

	import org.xmlpull.v1.XmlPullParser;
	import org.xmlpull.v1.XmlPullParserException;
	import org.xmlpull.v1.XmlSerializer;

	import java.io.IOException;
	import java.util.ArrayList;
	import java.util.List;
	import java.util.Locale;
	import java.util.regex.Pattern;

	/**********************************************************************
	* This file is not a part of the NFC mainline module *
	* *******************************************************************/

	/**
	* The AidGroup class represents a group of Application Identifiers (AIDs).
	*
	* <p>The format of AIDs is defined in the ISO/IEC 7816-4 specification. This class
	* requires the AIDs to be input as a hexadecimal string, with an even amount of
	* hexadecimal characters, e.g. "F014811481".
	*
	* @hide
	*/
	@SystemApi
	@FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
	public final class AidGroup implements Parcelable {
	/**
	* The maximum number of AIDs that can be present in any one group.
	*/
	private static final int MAX_NUM_AIDS = 256;

	private static final String TAG = "AidGroup";


	private final List<String> mAids;
	private final String mCategory;
	@SuppressWarnings("unused") // Unused as of now, but part of the XML input.
	private final String mDescription;

	/**
	* Creates a new AidGroup object.
	*
	* @param aids list of AIDs present in the group
	* @param category category of this group, e.g. {@link CardEmulation#CATEGORY_PAYMENT}
	*/
	@FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
	public AidGroup(@NonNull List<String> aids, @Nullable String category) {
	if (aids == null \|\| aids.size() == 0) {
	throw new IllegalArgumentException("No AIDS in AID group.");
	}
	if (aids.size() > MAX_NUM_AIDS) {
	throw new IllegalArgumentException("Too many AIDs in AID group.");
	}
	for (String aid : aids) {
	if (!isValidAid(aid)) {
	throw new IllegalArgumentException("AID " + aid + " is not a valid AID.");
	}
	}
	if (isValidCategory(category)) {
	this.mCategory = category;
	} else {
	this.mCategory = CardEmulation.CATEGORY_OTHER;
	}
	this.mAids = new ArrayList<String>(aids.size());
	for (String aid : aids) {
	this.mAids.add(aid.toUpperCase(Locale.US));
	}
	this.mDescription = null;
	}

	/**
	* Creates a new AidGroup object.
	*
	* @param category category of this group, e.g. {@link CardEmulation#CATEGORY_PAYMENT}
	* @param description description of this group
	*/
	AidGroup(@NonNull String category, @NonNull String description) {
	this.mAids = new ArrayList<String>();
	this.mCategory = category;
	this.mDescription = description;
	}

	/**
	* Returns the category of this group.
	* @return the category of this AID group
	*/
	@FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
	@NonNull
	public String getCategory() {
	return mCategory;
	}

	/**
	* Returns the list of AIDs in this group.
	*
	* @return the list of AIDs in this group
	*/
	@FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
	@NonNull
	public List<String> getAids() {
	return mAids;
	}

	@Override
	public String toString() {
	StringBuilder out = new StringBuilder("Category: " + mCategory
	+ ", AIDs:");
	for (String aid : mAids) {
	out.append(aid);
	out.append(", ");
	}
	return out.toString();
	}

	/**
	* Dump debugging info as AidGroupProto.
	*
	* If the output belongs to a sub message, the caller is responsible for wrapping this function
	* between {@link ProtoOutputStream#start(long)} and {@link ProtoOutputStream#end(long)}.
	*
	* @param proto the ProtoOutputStream to write to
	*/
	@FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
	public void dump(@NonNull ProtoOutputStream proto) {
	proto.write(AidGroupProto.CATEGORY, mCategory);
	for (String aid : mAids) {
	proto.write(AidGroupProto.AIDS, aid);
	}
	}

	@FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
	@Override
	public int describeContents() {
	return 0;
	}

	@FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
	@Override
	public void writeToParcel(@NonNull Parcel dest, int flags) {
	dest.writeString8(mCategory);
	dest.writeInt(mAids.size());
	if (mAids.size() > 0) {
	dest.writeStringList(mAids);
	}
	}

	@FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
	public static final @NonNull Parcelable.Creator<AidGroup> CREATOR =
	new Parcelable.Creator<AidGroup>() {

	@Override
	public AidGroup createFromParcel(Parcel source) {
	String category = source.readString8();
	int listSize = source.readInt();
	ArrayList<String> aidList = new ArrayList<String>();
	if (listSize > 0) {
	source.readStringList(aidList);
	}
	return new AidGroup(aidList, category);
	}

	@Override
	public AidGroup[] newArray(int size) {
	return new AidGroup[size];
	}
	};

	/**
	* Create an instance of AID group from XML file.
	*
	* @param parser input xml parser stream
	* @throws XmlPullParserException If an error occurs parsing the element.
	* @throws IOException If an error occurs reading the element.
	*/
	@FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
	@Nullable
	public static AidGroup createFromXml(@NonNull XmlPullParser parser)
	throws XmlPullParserException, IOException {
	String category = null;
	ArrayList<String> aids = new ArrayList<String>();
	AidGroup group = null;
	boolean inGroup = false;

	int eventType = parser.getEventType();
	int minDepth = parser.getDepth();
	while (eventType != XmlPullParser.END_DOCUMENT && parser.getDepth() >= minDepth) {
	String tagName = parser.getName();
	if (eventType == XmlPullParser.START_TAG) {
	if (tagName.equals("aid")) {
	if (inGroup) {
	String aid = parser.getAttributeValue(null, "value");
	if (aid != null) {
	aids.add(aid.toUpperCase());
	}
	} else {
	Log.d(TAG, "Ignoring <aid> tag while not in group");
	}
	} else if (tagName.equals("aid-group")) {
	category = parser.getAttributeValue(null, "category");
	if (category == null) {
	Log.e(TAG, "<aid-group> tag without valid category");
	return null;
	}
	inGroup = true;
	} else {
	Log.d(TAG, "Ignoring unexpected tag: " + tagName);
	}
	} else if (eventType == XmlPullParser.END_TAG) {
	if (tagName.equals("aid-group") && inGroup && aids.size() > 0) {
	group = new AidGroup(aids, category);
	break;
	}
	}
	eventType = parser.next();
	}
	return group;
	}

	/**
	* Serialize instance of AID group to XML file.
	* @param out XML serializer stream
	* @throws IOException If an error occurs reading the element.
	*/
	@FlaggedApi(Flags.FLAG_ENABLE_NFC_MAINLINE)
	public void writeAsXml(@NonNull XmlSerializer out) throws IOException {
	out.startTag(null, "aid-group");
	out.attribute(null, "category", mCategory);
	for (String aid : mAids) {
	out.startTag(null, "aid");
	out.attribute(null, "value", aid);
	out.endTag(null, "aid");
	}
	out.endTag(null, "aid-group");
	}

	private static boolean isValidCategory(String category) {
	return CardEmulation.CATEGORY_PAYMENT.equals(category) \|\|
	CardEmulation.CATEGORY_OTHER.equals(category);
	}

	private static final Pattern AID_PATTERN = Pattern.compile("[0-9A-Fa-f]{10,32}\\*?\\#?");
	/**
	* Copied over from {@link CardEmulation#isValidAid(String)}
	* @hide
	*/
	private static boolean isValidAid(String aid) {
	if (aid == null)
	return false;

	// If a prefix/subset AID, the total length must be odd (even # of AID chars + '*')
	if ((aid.endsWith("*") \|\| aid.endsWith("#")) && ((aid.length() % 2) == 0)) {
	Log.e(TAG, "AID " + aid + " is not a valid AID.");
	return false;
	}

	// If not a prefix/subset AID, the total length must be even (even # of AID chars)
	if ((!(aid.endsWith("*") \|\| aid.endsWith("#"))) && ((aid.length() % 2) != 0)) {
	Log.e(TAG, "AID " + aid + " is not a valid AID.");
	return false;
	}

	// Verify hex characters
	if (!AID_PATTERN.matcher(aid).matches()) {
	Log.e(TAG, "AID " + aid + " is not a valid AID.");
	return false;
	}

	return true;
	}
	}