4 files changed, 21 insertions, 11 deletions
diff --git a/src/main/model/asn1/ASN1Time.java b/src/main/model/asn1/ASN1Time.java
index 8f386f5..94e58b3 100644
--- a/src/main/model/asn1/ASN1Time.java
+++ b/src/main/model/asn1/ASN1Time.java
@@ -15,7 +15,7 @@ public abstract class ASN1Time extends ASN1Object {
     /**
      * The time.
      */
-    private ZonedDateTime timestamp;
+    private final ZonedDateTime timestamp;
 
     /**
      * EFFECTS: Initialize the time with the specific tag, parentTag, and timestamp. For tag and parentTag, consult
diff --git a/src/main/model/asn1/GeneralizedTime.java b/src/main/model/asn1/GeneralizedTime.java
index 5482906..c97a51b 100644
--- a/src/main/model/asn1/GeneralizedTime.java
+++ b/src/main/model/asn1/GeneralizedTime.java
@@ -22,7 +22,7 @@ public class GeneralizedTime extends ASN1Time {
     /**
      * Rather stupid impl ...
      */
-    private static final DateTimeFormatter formatterNoSecs = new DateTimeFormatterBuilder()
+    private static final DateTimeFormatter FORMATTER_NO_SECS = new DateTimeFormatterBuilder()
             .appendValue(ChronoField.YEAR, 4)
             .appendValue(ChronoField.MONTH_OF_YEAR, 2)
             .appendValue(ChronoField.DAY_OF_MONTH, 2)
@@ -32,7 +32,7 @@ public class GeneralizedTime extends ASN1Time {
             .toFormatter()
             .withZone(ZoneId.of("UTC"));
 
-    private static final DateTimeFormatter formatter = new DateTimeFormatterBuilder()
+    private static final DateTimeFormatter FORMATTER = new DateTimeFormatterBuilder()
             .appendValue(ChronoField.YEAR, 4)
             .appendValue(ChronoField.MONTH_OF_YEAR, 2)
             .appendValue(ChronoField.DAY_OF_MONTH, 2)
@@ -71,7 +71,7 @@ public class GeneralizedTime extends ASN1Time {
     @Override
     public ZonedDateTime toDate(String str) throws ParseException {
         try {
-            return ZonedDateTime.parse(str, formatter);
+            return ZonedDateTime.parse(str, FORMATTER);
         } catch (DateTimeParseException e) {
             throw new ParseException(e.getMessage());
         }
@@ -83,8 +83,8 @@ public class GeneralizedTime extends ASN1Time {
     @Override
     public String toString() {
         if (getTimestamp().getSecond() == 0) {
-            return getTimestamp().format(formatterNoSecs);
+            return getTimestamp().format(FORMATTER_NO_SECS);
         }
-        return getTimestamp().format(formatter);
+        return getTimestamp().format(FORMATTER);
     }
 }
diff --git a/src/main/model/asn1/UtcTime.java b/src/main/model/asn1/UtcTime.java
index 7fa93d1..54b7a5a 100644
--- a/src/main/model/asn1/UtcTime.java
+++ b/src/main/model/asn1/UtcTime.java
@@ -23,7 +23,7 @@ public class UtcTime extends ASN1Time {
     /**
      * Rather stupid impl ...
      */
-    private static final DateTimeFormatter formatterNoSecs = new DateTimeFormatterBuilder()
+    private static final DateTimeFormatter FORMATTER_NO_SECS = new DateTimeFormatterBuilder()
             .appendPattern("yy")
             .appendValue(ChronoField.MONTH_OF_YEAR, 2)
             .appendValue(ChronoField.DAY_OF_MONTH, 2)
@@ -33,7 +33,7 @@ public class UtcTime extends ASN1Time {
             .toFormatter()
             .withZone(ZoneId.of("UTC"));
 
-    private static final DateTimeFormatter formatter = new DateTimeFormatterBuilder()
+    private static final DateTimeFormatter FORMATTER = new DateTimeFormatterBuilder()
             .appendPattern("yy")
             .appendValue(ChronoField.MONTH_OF_YEAR, 2)
             .appendValue(ChronoField.DAY_OF_MONTH, 2)
@@ -72,7 +72,7 @@ public class UtcTime extends ASN1Time {
     @Override
     public ZonedDateTime toDate(String str) throws ParseException {
         try {
-            return ZonedDateTime.parse(str, formatter);
+            return ZonedDateTime.parse(str, FORMATTER);
         } catch (DateTimeParseException e) {
             throw new ParseException(e.getMessage());
         }
@@ -84,8 +84,8 @@ public class UtcTime extends ASN1Time {
     @Override
     public String toString() {
         if (getTimestamp().getSecond() == 0) {
-            return getTimestamp().format(formatterNoSecs);
+            return getTimestamp().format(FORMATTER_NO_SECS);
         }
-        return getTimestamp().format(formatter);
+        return getTimestamp().format(FORMATTER);
     }
 }
diff --git a/src/main/model/asn1/exceptions/InvalidCAException.java b/src/main/model/asn1/exceptions/InvalidCAException.java
new file mode 100644
index 0000000..e487509
--- /dev/null
+++ b/src/main/model/asn1/exceptions/InvalidCAException.java
@@ -0,0 +1,10 @@
+package model.asn1.exceptions;
+
+/**
+ * Indicate the error that the CA being installed is invalid.
+ */
+public class InvalidCAException extends Exception {
+    public InvalidCAException(String message) {
+        super(message);
+    }
+}