1 files changed, 16 insertions, 14 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/asn1/ASN1UTCTime.java b/bcprov/src/main/java/org/bouncycastle/asn1/ASN1UTCTime.java
index d2909370..d9a26291 100644
--- a/bcprov/src/main/java/org/bouncycastle/asn1/ASN1UTCTime.java
+++ b/bcprov/src/main/java/org/bouncycastle/asn1/ASN1UTCTime.java
@@ -90,7 +90,7 @@ public class ASN1UTCTime
         }
         else
         {
-            return new ASN1UTCTime(((ASN1OctetString)o).getOctets());
+            return new ASN1UTCTime(ASN1OctetString.getInstance(o).getOctets());
         }
     }
 
@@ -159,7 +159,15 @@ public class ASN1UTCTime
     ASN1UTCTime(
         byte[] time)
     {
+        if (time.length < 2)
+        {
+            throw new IllegalArgumentException("UTCTime string too short");
+        }
         this.time = time;
+        if (!(isDigit(0) && isDigit(1)))
+        {
+            throw new IllegalArgumentException("illegal characters in UTCTime string");
+        }
     }
 
     /**
@@ -275,6 +283,11 @@ public class ASN1UTCTime
         }
     }
 
+    private boolean isDigit(int pos)
+    {
+        return time.length > pos && time[pos] >= '0' && time[pos] <= '9';
+    }
+
     boolean isConstructed()
     {
         return false;
@@ -287,20 +300,9 @@ public class ASN1UTCTime
         return 1 + StreamUtil.calculateBodyLength(length) + length;
     }
 
-    void encode(
-        ASN1OutputStream  out)
-        throws IOException
+    void encode(ASN1OutputStream out, boolean withTag) throws IOException
     {
-        out.write(BERTags.UTC_TIME);
-
-        int length = time.length;
-
-        out.writeLength(length);
-
-        for (int i = 0; i != length; i++)
-        {
-            out.write((byte)time[i]);
-        }
+        out.writeEncoded(withTag, BERTags.UTC_TIME, time);
     }
 
     boolean asn1Equals(