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Commit 12b110e5 authored by Khaled Abdelmohsen's avatar Khaled Abdelmohsen
Browse files

Implement XML parsing for atomic formula 

Parse a rule's atomic formula and effect, and wrap the result in a rule
to be appended to the list of rules parsed so far.

Bug: 143697198
Test: atest FrameworksServicesTests:RuleXmlParserTest
Change-Id: If09503472060929c6ab914b3b178c14c0e7cd314
parent 0a181cd8

services/core/java/com/android/server/integrity/parser/RuleXmlParser.java

+114 −3
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ package com.android.server.integrity.parser; 
import android.util.Slog;

import android.util.Xml;



import com.android.server.integrity.model.AtomicFormula;

import com.android.server.integrity.model.Formula;

import com.android.server.integrity.model.Rule;



import org.xmlpull.v1.XmlPullParser;
@@ -38,8 +40,15 @@ public final class RuleXmlParser implements RuleParser { 


    public static final String TAG = "RuleXmlParser";



    // TODO: Use XML attributes

    private static final String RULE_LIST_TAG = "RuleList";

    private static final String RULE_TAG = "Rule";

    private static final String OPEN_FORMULA_TAG = "OpenFormula";

    private static final String ATOMIC_FORMULA_TAG = "AtomicFormula";

    private static final String EFFECT_TAG = "Effect";

    private static final String KEY_TAG = "Key";

    private static final String OPERATOR_TAG = "Operator";

    private static final String VALUE_TAG = "Value";



    @Override

    public List<Rule> parse(String ruleText) {
@@ -65,7 +74,8 @@ public final class RuleXmlParser implements RuleParser { 
        return null;

    }



    private List<Rule> parseRules(XmlPullParser parser) throws IOException, XmlPullParserException {

    private static List<Rule> parseRules(XmlPullParser parser)

            throws IOException, XmlPullParserException {

        List<Rule> rules = new ArrayList<>();



        // Skipping the first event type, which is always {@link XmlPullParser.START_DOCUMENT}
@@ -98,8 +108,109 @@ public final class RuleXmlParser implements RuleParser { 
        return rules;

    }



    private Rule parseRule(XmlPullParser parser) {

        // TODO: Implement rule parser.

    private static Rule parseRule(XmlPullParser parser) {

        try {

            Formula formula = null;

            @Rule.Effect int effect = 0;



            boolean isValid = true;

            int eventType;

            while ((eventType = parser.next()) != XmlPullParser.END_DOCUMENT) {

                String nodeName = parser.getName();



                if (eventType == XmlPullParser.END_TAG && parser.getName().equals(RULE_TAG)) {

                    break;

                }



                if (eventType == XmlPullParser.START_TAG) {

                    switch (nodeName) {

                        case OPEN_FORMULA_TAG:

                            formula = parseOpenFormula(parser);

                            break;

                        case ATOMIC_FORMULA_TAG:

                            formula = parseAtomicFormula(parser);

                            break;

                        case EFFECT_TAG:

                            effect = Integer.parseInt(extractValue(parser));

                            break;

                        default:

                            isValid = false;

                    }

                } else {

                    isValid = false;

                }

            }



            return isValid ? new Rule(formula, effect) : null;

        } catch (Exception e) {

            // In case of any exceptions arising from constructing the rule, it will be skipped.

            // Rules are assumed to be validated on the server.

            return null;

        }

    }



    private static Formula parseOpenFormula(XmlPullParser parser) {

        // TODO: Implement open formula parser.

        return null;

    }



    private static Formula parseAtomicFormula(XmlPullParser parser)

            throws IOException, XmlPullParserException {

        @AtomicFormula.Key int key = 0;

        @AtomicFormula.Operator int operator = 0;

        String value = null;



        boolean isValid = true;

        int eventType;

        while ((eventType = parser.next()) != XmlPullParser.END_DOCUMENT) {

            String nodeName = parser.getName();



            if (eventType == XmlPullParser.END_TAG && parser.getName().equals(ATOMIC_FORMULA_TAG)) {

                break;

            }



            if (eventType == XmlPullParser.START_TAG) {

                switch (nodeName) {

                    case KEY_TAG:

                        key = Integer.parseInt(extractValue(parser));

                        break;

                    case OPERATOR_TAG:

                        operator = Integer.parseInt(extractValue(parser));

                        break;

                    case VALUE_TAG:

                        value = extractValue(parser);

                        break;

                    default:

                        isValid = false;

                }

            }

        }

        return isValid ? constructAtomicFormulaBasedOnKey(key, operator, value) : null;

    }



    private static Formula constructAtomicFormulaBasedOnKey(@AtomicFormula.Key int key,

            @AtomicFormula.Operator int operator, String value) {

        switch (key) {

            case AtomicFormula.PACKAGE_NAME:

            case AtomicFormula.INSTALLER_NAME:

            case AtomicFormula.APP_CERTIFICATE:

            case AtomicFormula.INSTALLER_CERTIFICATE:

                return new AtomicFormula.StringAtomicFormula(key, value);

            case AtomicFormula.PRE_INSTALLED:

                return new AtomicFormula.BooleanAtomicFormula(key, Boolean.parseBoolean(value));

            case AtomicFormula.VERSION_CODE:

                return new AtomicFormula.IntAtomicFormula(key, operator, Integer.parseInt(value));

            default:

                return null;

        }

    }



    private static String extractValue(XmlPullParser parser)

            throws IOException, XmlPullParserException {

        String value = null;

        if (parser.next() == XmlPullParser.TEXT) {

            value = parser.getText();

        }

        return parser.next() == XmlPullParser.END_TAG ? value : null;

    }

}

services/tests/servicestests/src/com/android/server/integrity/parser/RuleXmlParserTest.java

+142 −16
Original line number Diff line number Diff line
@@ -18,9 +18,10 @@ package com.android.server.integrity.parser; 


import static com.android.server.testutils.TestUtils.assertExpectException;



import static org.junit.Assert.assertNotNull;

import static org.junit.Assert.assertTrue;

import static com.google.common.truth.Truth.assertThat;



import com.android.server.integrity.model.AtomicFormula;

import com.android.server.integrity.model.OpenFormula;

import com.android.server.integrity.model.Rule;



import org.junit.Test;
@@ -29,6 +30,7 @@ import org.junit.runners.JUnit4; 


import java.io.ByteArrayInputStream;

import java.io.InputStream;

import java.util.Collections;

import java.util.List;



@RunWith(JUnit4.class)
@@ -37,14 +39,14 @@ public class RuleXmlParserTest { 
    private static final String VALID_RULE_XML = "<RuleList>"

            + "<Rule>"

            + "<OpenFormula>"

            + "<Connector>NOT</Connector>"

            + "<Connector>" + OpenFormula.NOT + "</Connector>"

            + "<AtomicFormula>"

            + "<Key>PACKAGE_NAME</Key>"

            + "<Operator>EQ</Operator>"

            + "<Key>" + AtomicFormula.PACKAGE_NAME + "</Key>"

            + "<Operator>" + AtomicFormula.EQ + "</Operator>"

            + "<Value>com.app.test</Value>"

            + "</AtomicFormula>"

            + "</OpenFormula>"

            + "<Effect>DENY</Effect>"

            + "<Effect>" + Rule.DENY + "</Effect>"

            + "</Rule>"

            + "</RuleList>";
@@ -54,8 +56,7 @@ public class RuleXmlParserTest { 


        List<Rule> rules = xmlParser.parse(VALID_RULE_XML);



        assertNotNull(rules);

        assertTrue(rules.isEmpty());

        assertThat(rules).isEmpty();

    }



    @Test
@@ -65,8 +66,133 @@ public class RuleXmlParserTest { 


        List<Rule> rules = xmlParser.parse(inputStream);



        assertNotNull(rules);

        assertTrue(rules.isEmpty());

        assertThat(rules).isEmpty();

    }



    @Test

    public void testXmlString_validAtomicFormula_stringValue() {

        String ruleXmlAtomicFormula = "<RuleList>"

                + "<Rule>"

                + "<AtomicFormula>"

                + "<Key>" + AtomicFormula.PACKAGE_NAME + "</Key>"

                + "<Operator>" + AtomicFormula.EQ + "</Operator>"

                + "<Value>com.app.test</Value>"

                + "</AtomicFormula>"

                + "<Effect>" + Rule.DENY + "</Effect>"

                + "</Rule>"

                + "</RuleList>";

        RuleParser xmlParser = new RuleXmlParser();

        Rule expectedRule = new Rule(

                new AtomicFormula.StringAtomicFormula(AtomicFormula.PACKAGE_NAME, "com.app.test"),

                Rule.DENY);



        List<Rule> rules = xmlParser.parse(ruleXmlAtomicFormula);



        assertThat(rules).isEqualTo(Collections.singletonList(expectedRule));

    }



    @Test

    public void testXmlString_validAtomicFormula_integerValue() {

        String ruleXmlAtomicFormula = "<RuleList>"

                + "<Rule>"

                + "<AtomicFormula>"

                + "<Key>" + AtomicFormula.VERSION_CODE + "</Key>"

                + "<Operator>" + AtomicFormula.EQ + "</Operator>"

                + "<Value>1</Value>"

                + "</AtomicFormula>"

                + "<Effect>" + Rule.DENY + "</Effect>"

                + "</Rule>"

                + "</RuleList>";

        RuleParser xmlParser = new RuleXmlParser();

        Rule expectedRule = new Rule(

                new AtomicFormula.IntAtomicFormula(AtomicFormula.VERSION_CODE, AtomicFormula.EQ, 1),

                Rule.DENY);



        List<Rule> rules = xmlParser.parse(ruleXmlAtomicFormula);



        assertThat(rules).isEqualTo(Collections.singletonList(expectedRule));

    }



    @Test

    public void testXmlString_validAtomicFormula_booleanValue() {

        String ruleXmlAtomicFormula = "<RuleList>"

                + "<Rule>"

                + "<AtomicFormula>"

                + "<Key>" + AtomicFormula.PRE_INSTALLED + "</Key>"

                + "<Operator>" + AtomicFormula.EQ + "</Operator>"

                + "<Value>true</Value>"

                + "</AtomicFormula>"

                + "<Effect>" + Rule.DENY + "</Effect>"

                + "</Rule>"

                + "</RuleList>";

        RuleParser xmlParser = new RuleXmlParser();

        Rule expectedRule = new Rule(

                new AtomicFormula.BooleanAtomicFormula(AtomicFormula.PRE_INSTALLED, true),

                Rule.DENY);



        List<Rule> rules = xmlParser.parse(ruleXmlAtomicFormula);



        assertThat(rules).isEqualTo(Collections.singletonList(expectedRule));

    }



    @Test

    public void testXmlString_validAtomicFormula_differentTagOrder() {

        String ruleXmlAtomicFormula = "<RuleList>"

                + "<Rule>"

                + "<AtomicFormula>"

                + "<Operator>" + AtomicFormula.EQ + "</Operator>"

                + "<Value>com.app.test</Value>"

                + "<Key>" + AtomicFormula.PACKAGE_NAME + "</Key>"

                + "</AtomicFormula>"

                + "<Effect>" + Rule.DENY + "</Effect>"

                + "</Rule>"

                + "</RuleList>";

        RuleParser xmlParser = new RuleXmlParser();

        Rule expectedRule = new Rule(

                new AtomicFormula.StringAtomicFormula(AtomicFormula.PACKAGE_NAME, "com.app.test"),

                Rule.DENY);



        List<Rule> rules = xmlParser.parse(ruleXmlAtomicFormula);



        assertThat(rules).isEqualTo(Collections.singletonList(expectedRule));

    }



    @Test

    public void testXmlString_invalidAtomicFormula_invalidTags() {

        String ruleXmlAtomicFormula = "<RuleList>"

                + "<Rule>"

                + "<AtomicFormula>"

                + "<BadKey>" + AtomicFormula.PACKAGE_NAME + "</BadKey>"

                + "<Operator>" + AtomicFormula.EQ + "</Operator>"

                + "<Value>com.app.test</Value>"

                + "</AtomicFormula>"

                + "<Effect>" + Rule.DENY + "</Effect>"

                + "</Rule>"

                + "</RuleList>";

        RuleParser xmlParser = new RuleXmlParser();



        List<Rule> rules = xmlParser.parse(ruleXmlAtomicFormula);



        assertThat(rules).isEmpty();

    }



    @Test

    public void testXmlString_invalidAtomicFormula() {

        String ruleXmlAtomicFormula = "<RuleList>"

                + "<Rule>"

                + "<AtomicFormula>"

                + "<Key>" + AtomicFormula.VERSION_CODE + "</Key>"

                + "<Operator>" + AtomicFormula.EQ + "</Operator>"

                + "<Value>com.app.test</Value>"

                + "</AtomicFormula>"

                + "<Effect>" + Rule.DENY + "</Effect>"

                + "</Rule>"

                + "</RuleList>";

        RuleParser xmlParser = new RuleXmlParser();



        List<Rule> rules = xmlParser.parse(ruleXmlAtomicFormula);



        assertThat(rules).isEmpty();

    }



    @Test
@@ -75,12 +201,12 @@ public class RuleXmlParserTest { 
                + "<OpenFormula>"

                + "<Connector>NOT</Connector>"

                + "<AtomicFormula>"

                + "<Key>PACKAGE_NAME</Key>"

                + "<Operator>EQ</Operator>"

                + "<Key>" + AtomicFormula.PACKAGE_NAME + "</Key>"

                + "<Operator>" + AtomicFormula.EQ + "</Operator>"

                + "<Value>com.app.test</Value>"

                + "</AtomicFormula>"

                + "</OpenFormula>"

                + "<Effect>DENY</Effect>"

                + "<Effect>" + Rule.DENY + "</Effect>"

                + "</Rule>";

        RuleParser xmlParser = new RuleXmlParser();
@@ -96,12 +222,12 @@ public class RuleXmlParserTest { 
                + "<OpenFormula>"

                + "<Connector>NOT</Connector>"

                + "<AtomicFormula>"

                + "<Key>PACKAGE_NAME</Key>"

                + "<Operator>EQ</Operator>"

                + "<Key>" + AtomicFormula.PACKAGE_NAME + "</Key>"

                + "<Operator>" + AtomicFormula.EQ + "</Operator>"

                + "<Value>com.app.test</Value>"

                + "</AtomicFormula>"

                + "</OpenFormula>"

                + "<Effect>DENY</Effect>"

                + "<Effect>" + Rule.DENY + "</Effect>"

                + "</Rule>";

        InputStream inputStream = new ByteArrayInputStream(ruleXmlWithNoRuleList.getBytes());

        RuleParser xmlParser = new RuleXmlParser();