Validate file arguments with FileArgumentValidator

tools/tcg_rim_tool/src/main/java/hirs/swid/Main.java

@@ -55,22 +55,14 @@ public class Main {
                 String rimel = commander.getRimEventLog();
                 String certificateFile = commander.getPublicCertificate();
                 String trustStore = commander.getTruststoreFile();
-                if (!verifyFile.isEmpty()) {
                     validator.setRim(verifyFile);
-                    if (!rimel.isEmpty()) {
                     validator.setRimEventLog(rimel);
-                    }
-                    if (!trustStore.isEmpty()) {
                     validator.setTrustStoreFile(trustStore);
-                    }
                     if (!certificateFile.isEmpty()) {
                         System.out.println("A single cert cannot be used for verification. " +
                                 "The signing cert will be searched for in the trust store.");
                     }
                     validator.validateSwidtagFile(verifyFile);
-                } else {
-                    exitWithErrorCode("A RIM file was not found for validation.");
-                }
             } else {
                 gateway = new SwidTagGateway();
                 if (commander.isVerbose()) {

tools/tcg_rim_tool/src/main/java/hirs/swid/utils/Commander.java

@@ -19,12 +19,12 @@ public class Commander {
     @Parameter(names = {"-c", "--create \"base\""}, order = 0,
             description = "The type of RIM to create. A base RIM will be created by default.")
     private String createType = "";
-    @Parameter(names = {"-v", "--verify <path>"}, order = 3,
+    @Parameter(names = {"-v", "--verify <path>"}, validateWith = FileArgumentValidator.class,
             description = "Specify a RIM file to verify.")
     private String verifyFile = "";
     @Parameter(names = {"-V", "--version"}, description = "Output the current version.")
     private boolean version = false;
-    @Parameter(names = {"-a", "--attributes <path>"}, order = 1,
+    @Parameter(names = {"-a", "--attributes <path>"}, validateWith = FileArgumentValidator.class,
             description = "The configuration file holding attributes "
             + "to populate the base RIM with.")
     private String attributesFile = "";
@@ -34,14 +34,16 @@ public class Commander {
     private String outFile = "";
     @Parameter(names = {"--verbose"}, description = "Control output verbosity.")
     private boolean verbose = false;
-    @Parameter(names = {"-t", "--truststore <path>"}, order = 4,
+    @Parameter(names = {"-t", "--truststore <path>"}, validateWith = FileArgumentValidator.class,
             description = "The truststore to sign the base RIM created "
             + "or to validate the signed base RIM.")
     private String truststoreFile = "";
-    @Parameter(names = {"-k", "--privateKeyFile <path>"}, order = 5,
+    @Parameter(names = {"-k", "--privateKeyFile <path>"},
+            validateWith = FileArgumentValidator.class,
             description = "The private key used to sign the base RIM created by this tool.")
     private String privateKeyFile = "";
-    @Parameter(names = {"-p", "--publicCertificate <path>"}, order = 6,
+    @Parameter(names = {"-p", "--publicCertificate <path>"},
+            validateWith = FileArgumentValidator.class,
             description = "The public key certificate to embed in the base RIM created by "
             + "this tool.")
     private String publicCertificate = "";
@@ -51,7 +53,7 @@ public class Commander {
     @Parameter(names = {"-d", "--default-key"}, order = 8,
             description = "Use default signing credentials.")
     private boolean defaultKey = false;
-    @Parameter(names = {"-l", "--rimel <path>"}, order = 9,
+    @Parameter(names = {"-l", "--rimel <path>"}, validateWith = FileArgumentValidator.class,
             description = "The TCG eventlog file to use as a support RIM.")
     private String rimEventLog = "";
     @Parameter(names = {"--timestamp"}, order = 10, variableArity = true,

tools/tcg_rim_tool/src/main/java/hirs/swid/utils/FileArgumentValidator.java

@@ -0,0 +1,33 @@
+package hirs.swid.utils;
+
+import com.beust.jcommander.IParameterValidator;
+import com.beust.jcommander.ParameterException;
+
+import java.io.File;
+import lombok.extern.log4j.Log4j2;
+
+/**
+ * This class validates arguments that take a String path to a file.
+ * The file path is checked for null, and if the file is found it is checked
+ * for validity, emptiness, and read permissions.
+ */
+@Log4j2
+public class FileArgumentValidator implements IParameterValidator {
+    public void validate(String name, String value) throws ParameterException {
+        try {
+            File file = new File(value);
+            if (!file.isFile()) {
+                throw new ParameterException("Invalid file path: " + value +
+                        ". Please verify file path.");
+            }
+            if (file.length() == 0) {
+                throw new ParameterException("File " + value + " is empty.");
+            }
+        } catch (NullPointerException e) {
+            throw new ParameterException("File path cannot be null: " + e.getMessage());
+        } catch (SecurityException e) {
+            throw new ParameterException("Read access denied for " + value +
+                    ", please verify permissions.");
+        }
+    }
+}