Add a policy parser for java agent

Signed-off-by: Gulshan <kumargu@amazon.com>

Author: kumargu

gradle/missing-javadoc.gradle

@@ -106,6 +106,7 @@ configure([
   project(":libs:opensearch-secure-sm"),
   project(":libs:opensearch-ssl-config"),
   project(":libs:opensearch-x-content"),
+  project(":libs:agent-sm:agent-policy"),
   project(":modules:aggs-matrix-stats"),
   project(":modules:analysis-common"),
   project(":modules:geo"),

libs/agent-sm/agent-policy/build.gradle

@@ -0,0 +1,27 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+apply plugin: 'opensearch.build'
+apply plugin: 'opensearch.publish'
+
+ext {
+  failOnJavadocWarning = false
+}
+
+base {
+  archivesName = 'opensearch-agent-policy'
+}
+
+disableTasks('forbiddenApisMain')
+
+dependencies {
+  testImplementation(project(":test:framework"))
+}

libs/agent-sm/agent-policy/src/main/java/org/opensearch/secure_sm/policy/GrantNode.java

@@ -0,0 +1,52 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.secure_sm.policy;
+
+import java.io.PrintWriter;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.LinkedList;
+
+public class GrantNode {
+    public String codeBase;
+    private final LinkedList<PermissionNode> permissionEntries = new LinkedList<>();
+
+    public void add(PermissionNode entry) {
+        permissionEntries.add(entry);
+    }
+
+    public Enumeration<PermissionNode> permissionElements() {
+        return Collections.enumeration(permissionEntries);
+    }
+
+    public void write(PrintWriter out) {
+        out.print("grant");
+        if (codeBase != null) {
+            out.print(" Codebase \"");
+            out.print(codeBase);
+            out.print("\"");
+        }
+        out.println(" {");
+        for (PermissionNode pe : permissionEntries) {
+            out.print("  permission ");
+            out.print(pe.permission);
+            if (pe.name != null) {
+                out.print(" \"");
+                out.print(pe.name);
+                out.print("\"");
+            }
+            if (pe.action != null) {
+                out.print(", \"");
+                out.print(pe.action);
+                out.print("\"");
+            }
+            out.println(";");
+        }
+        out.println("};");
+    }
+}

libs/agent-sm/agent-policy/src/main/java/org/opensearch/secure_sm/policy/PermissionNode.java

@@ -0,0 +1,48 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.secure_sm.policy;
+
+import java.io.PrintWriter;
+import java.util.Objects;
+
+public class PermissionNode {
+    public String permission;
+    public String name;
+    public String action;
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(permission, name, action);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == this) return true;
+
+        return obj instanceof PermissionNode that
+            && Objects.equals(this.permission, that.permission)
+            && Objects.equals(this.name, that.name)
+            && Objects.equals(this.action, that.action);
+    }
+
+    public void write(PrintWriter out) {
+        out.print("permission ");
+        out.print(permission);
+        if (name != null) {
+            out.print(" \"");
+            out.print(name.replaceAll("\\\\", "\\\\\\\\").replaceAll("\"", "\\\\\\\""));
+            out.print('"');
+        }
+        if (action != null) {
+            out.print(", \"");
+            out.print(action);
+            out.print('"');
+        }
+        out.println(";");
+    }
+}

libs/agent-sm/agent-policy/src/main/java/org/opensearch/secure_sm/policy/PolicyEntry.java

@@ -0,0 +1,56 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.secure_sm.policy;
+
+import java.security.CodeSource;
+import java.security.Permission;
+import java.util.ArrayList;
+import java.util.List;
+
+public class PolicyEntry {
+
+    private final CodeSource codesource;
+    final List<Permission> permissions;
+
+    PolicyEntry(CodeSource cs) {
+        this.codesource = cs;
+        this.permissions = new ArrayList<Permission>();
+    }
+
+    /**
+     * add a Permission object to this entry.
+     * No need to sync add op because perms are added to entry only
+     * while entry is being initialized
+     */
+    void add(Permission p) {
+        permissions.add(p);
+    }
+
+    CodeSource getCodeSource() {
+        return codesource;
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        sb.append("{");
+        sb.append(getCodeSource());
+        sb.append("\n");
+        for (int j = 0; j < permissions.size(); j++) {
+            Permission p = permissions.get(j);
+            sb.append(" ");
+            sb.append(" ");
+            sb.append(p);
+            sb.append("\n");
+        }
+        sb.append("}");
+        sb.append("\n");
+        return sb.toString();
+    }
+}