Author: adc
Date: Tue Mar 1 14:46:31 2005
New Revision: 155835
URL: http://svn.apache.org/viewcvs?view=rev&rev=155835
Log:
The Length' s number of bytes must not be 127
http://issues.apache.org/jira/browse/DIRSNICKERS-102
Modified:
incubator/directory/asn1/trunk/ber/src/java/org/apache/asn1/ber/Length.java
incubator/directory/asn1/trunk/ber/src/test/org/apache/asn1/ber/LengthTest.java
Modified:
incubator/directory/asn1/trunk/ber/src/java/org/apache/asn1/ber/Length.java
URL:
http://svn.apache.org/viewcvs/incubator/directory/asn1/trunk/ber/src/java/org/apache/asn1/ber/Length.java?view=diff&r1=155834&r2=155835
==============================================================================
--- incubator/directory/asn1/trunk/ber/src/java/org/apache/asn1/ber/Length.java
(original)
+++ incubator/directory/asn1/trunk/ber/src/java/org/apache/asn1/ber/Length.java
Tue Mar 1 14:46:31 2005
@@ -32,8 +32,8 @@
public class Length
{
/** used to mark length as indefinate */
- public static final int INDEFINATE = -2 ;
- /** used to mark length as undefined */
+ public static final int INDEFINITE = -2 ;
+ /** used to mark length as undefined */
public static final int UNDEFINED = -1 ;
/** the end long form terminate bit flag mask */
public static final int END_MASK = 0x80 ;
@@ -44,21 +44,21 @@
private int numOctets = UNDEFINED ;
/** whether or not this length has been fixated */
private boolean isFixated = false ;
- /** a byte buffer used to collect the arriving length octets */
+ /** a byte buffer used to collect the arriving length octets */
private final ByteBuffer buf = ByteBuffer.allocate( 5 ) ;
/**
* Checks to see if the length has been fixated.
- *
+ *
* @return true if it is fixated, false if not
*/
public boolean isFixated()
{
return isFixated ;
}
-
-
+
+
/**
* Clears this tag's data of all bytes and values calculated so all is as
it
* was when this instance was created.
@@ -70,13 +70,13 @@
numOctets = 1 ;
buf.clear() ;
}
-
-
+
+
/**
- * Fixates the data within this Length calculating all the derived
+ * Fixates the data within this Length calculating all the derived
* properties from the existing set of octets. While fixated octets
* cannot be added.
- *
+ *
* @throws org.apache.asn1.codec.DecoderException if this Length is invalid
*/
void fixate() throws DecoderException
@@ -85,37 +85,52 @@
value = getLength( buf ) ;
isFixated = true ;
}
-
-
+
+
/**
* Adds an octet to this Length component and as a side effect fixates the
* Length component if all the required length data has arrived.
- *
+ *
* @param octet the 8 bit byte to add
*/
void add( byte octet ) throws DecoderException
{
if ( isFixated )
- {
+ {
throw new IllegalStateException( "data added to fixated length" ) ;
}
-
+
buf.put( octet ) ;
-
+
if ( buf.position() == 1 )
{
- // if its the long form
- if ( END_MASK == ( octet & END_MASK ) && ( octet & 0x7F ) > 0 )
+ // if its the long form, but not above 126 octets : (1)111 1111 is
not
+ // allowed : this value is reserved for future extension.
+ if ( END_MASK == ( octet & END_MASK ))
{
- // capture number of octets we need to compute length
- numOctets = octet & 0x7F ;
+ int typeLength = octet & 0x7F;
+
+ if (typeLength == 0)
+ {
+ numOctets = INDEFINITE;
+ fixate() ;
+ }
+ else if (typeLength == 0x7F)
+ {
+ throw new DecoderException( "The number of octets must
not be 127 (reserved for future extension) " ) ;
+ }
+ else
+ {
+ // capture number of octets we need to compute length
+ numOctets = octet & 0x7F ;
+ }
}
- else
- {
+ else
+ {
fixate() ;
}
}
-
+
/*
* if we have collected all the octets needed for computing the long
* form length so we need to calculate the length and just fixate
@@ -125,22 +140,22 @@
fixate() ;
}
}
-
-
+
+
/**
* Gets the length of the value.
- *
+ *
* @return the length of the value
*/
public int getLength()
{
return value ;
}
-
-
+
+
/**
* Gets the number of octets currently in this Length component.
- *
+ *
* @return the number of octets currently within this Length component
*/
public int size()
@@ -148,10 +163,10 @@
return buf.position() ;
}
-
+
/**
* Decodes the length of a value for a tlv using the Length field bytes.
- *
+ *
* @param octets the length field bytes in the TLV
* @return the length of the TLV
* @throws DecoderException if the precision cannot hold the number
@@ -167,20 +182,20 @@
*/
throw new DecoderException( "Length number is too large." ) ;
}
-
+
byte octet = octets.get() ;
-
+
// if we are using the short form then just return the first octet
if ( ( octet & END_MASK ) == 0 )
{
return octet ;
}
- // using the indefinate form
+ // using the indefinite form
else if ( ( octet & 0x7F ) == 0 )
{
- return INDEFINATE ;
+ return INDEFINITE ;
}
-
+
// using the long form so we calculate the length from all octets
int length = 0 ;
for ( int ii = octets.remaining(), shift = (ii-1)<<3; ii > 0; ii--,
shift -= 8 )
@@ -196,7 +211,7 @@
// shift += 8 ;
// }
// while ( octets.hasRemaining() ) ;
-
+
return length ;
}
}
Modified:
incubator/directory/asn1/trunk/ber/src/test/org/apache/asn1/ber/LengthTest.java
URL:
http://svn.apache.org/viewcvs/incubator/directory/asn1/trunk/ber/src/test/org/apache/asn1/ber/LengthTest.java?view=diff&r1=155834&r2=155835
==============================================================================
---
incubator/directory/asn1/trunk/ber/src/test/org/apache/asn1/ber/LengthTest.java
(original)
+++
incubator/directory/asn1/trunk/ber/src/test/org/apache/asn1/ber/LengthTest.java
Tue Mar 1 14:46:31 2005
@@ -237,4 +237,48 @@
assertEquals( 1, length.getLength() );
}
+
+ /**
+ * Test that a Length could not begin with a 0xFF byte, which is
+ * reserved for future extensions.
+ *
+ */
+ public void testRestrictedValueForFutureExtension()
+ {
+ Length length = new Length();
+
+ try
+ {
+ length.add( (byte) 0xFF ) ;
+ length.add( (byte) 0x01 ) ;
+ fail( "should fail before we get here" ) ;
+ }
+ catch ( DecoderException t )
+ {
+ assertNotNull( t ) ;
+ }
+ }
+
+ /**
+ * Test that an indefinite Length form is rejected.
+ *
+ */
+ public void testIndefiniteLength()
+ {
+ Length length = new Length();
+
+ try
+ {
+ length.add( (byte) 0x80 ) ;
+ length.add( (byte) 0x01 ) ;
+ length.add( (byte) 0x00 ) ;
+ length.add( (byte) 0x00 ) ;
+ fail( "should fail before we get here" ) ;
+ }
+ catch ( Throwable t )
+ {
+ assertNotNull( t ) ;
+ }
+ }
}
+
