org.mozilla.jss.asn1

Class BIT_STRING

java.lang.Object

org.mozilla.jss.asn1.BIT_STRING

All Implemented Interfaces:

ASN1Value

public class BIT_STRING
extends java.lang.Object
implements ASN1Value

An ASN.1 BIT STRING, which is an ordered sequence of bits. The bits are stored the same way they are encoded in BER: as an array of bytes with 0-7 unused bits at the end.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BIT_STRING.Template A class for decoding a BIT_STRING from its BER encoding.

Field Summary

Fields

Modifier and Type	Field and Description
static Form	FORM
static Tag	TAG

Constructor Summary

Constructors

Constructor and Description
BIT_STRING(java.util.BitSet bs, int numBits) Constructs a BIT_STRING from a BitSet.
BIT_STRING(byte[] bits, int padCount)

Method Summary

Modifier and Type	Method and Description
void	encode(java.io.OutputStream ostream) Write this value's DER encoding to an output stream using its own base tag.
void	encode(Tag implicitTag, java.io.OutputStream ostream) Write this value's DER encoding to an output stream using an implicit tag.
byte[]	getBits() Returns the bits packed into an array of bytes, with padding at the end.
int	getPadCount() Returns the number of padding bits at the end of the array.
boolean	getRemoveTrailingZeroes() Determines whether the DER-encoding of this bitstring will have its trailing zeroes removed.
Tag	getTag() Returns the base tag for this type, not counting any tags that may be imposed on it by its context.
static BIT_STRING.Template	getTemplate()
void	setRemoveTrailingZeroes(boolean removeTrailingZeroes) Determines whether the DER-encoding of this bitstring will have its trailing zeroes removed.
java.util.BitSet	toBitSet() Copies this BIT STRING into a Java BitSet.
boolean[]	toBooleanArray() Copies this BIT STRING into a boolean array.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

TAG

public static final Tag TAG

FORM

public static final Form FORM

Constructor Detail

BIT_STRING

public BIT_STRING(byte[] bits,
                  int padCount)
           throws java.lang.NumberFormatException

Parameters:

bits - The bits packed into an array of bytes, with padding at the end. The array may be empty (but not null), in which case padCount must be zero. The array is referenced, not cloned.

padCount - The number of padding bits at the end of the array. Must be in the range [0,7].

Throws:

java.lang.NumberFormatException - If padCount is not in the range [0,7], or bits is empty and padCount is non-zero.

BIT_STRING

public BIT_STRING(java.util.BitSet bs,
                  int numBits)
           throws java.lang.NumberFormatException

Constructs a BIT_STRING from a BitSet.

Parameters:

bs - A BitSet.

numBits - The number of bits to copy from the BitSet. This is necessary because the size of a BitSet is always padded up to a multiple of 64, but not all of these bits may be significant.

Throws:

java.lang.NumberFormatException - If numBits is larger than bs.size() or less than zero.

Method Detail

getRemoveTrailingZeroes

public boolean getRemoveTrailingZeroes()

Determines whether the DER-encoding of this bitstring will have its trailing zeroes removed. Generally, DER requires that trailing zeroes be removed when the bitstring is used to hold flags, but not when it is used to hold binary data (such as a public key). The default is false.

setRemoveTrailingZeroes

public void setRemoveTrailingZeroes(boolean removeTrailingZeroes)

Determines whether the DER-encoding of this bitstring will have its trailing zeroes removed. Generally, DER requires that trailing zeroes be removed when the bitstring is used to hold flags, but not when it is used to hold binary data (such as a public key). The default is false. If this bit string is used to hold flags, you should set this to true.

getBits

public byte[] getBits()

Returns the bits packed into an array of bytes, with padding at the end. The array may be empty (but not null), in which case padCount must be zero. The array is referenced, not cloned.

toBitSet

public java.util.BitSet toBitSet()

Copies this BIT STRING into a Java BitSet. Note that BitSet.size() will not accurately reflect the number of bits in the BIT STRING, because the size of a BitSet is always rounded up to the next multiple of 64. The extra bits will be set to 0.

toBooleanArray

public boolean[] toBooleanArray()

Copies this BIT STRING into a boolean array. Each element of the array represents one bit with true for 1 and false for 0.

getPadCount

public int getPadCount()

Returns the number of padding bits at the end of the array. Must be in the range [0,7].

getTag

public Tag getTag()

Description copied from interface: ASN1Value

Returns the base tag for this type, not counting any tags that may be imposed on it by its context.

Specified by:

getTag in interface ASN1Value

encode

public void encode(java.io.OutputStream ostream)
            throws java.io.IOException

Description copied from interface: ASN1Value

Write this value's DER encoding to an output stream using its own base tag.

Specified by:

encode in interface ASN1Value

Throws:

java.io.IOException

encode

public void encode(Tag implicitTag,
                   java.io.OutputStream ostream)
            throws java.io.IOException

Description copied from interface: ASN1Value

Write this value's DER encoding to an output stream using an implicit tag.

Specified by:

encode in interface ASN1Value

Throws:

java.io.IOException

getTemplate

public static BIT_STRING.Template getTemplate()