iaik.security.ec.common

Class ECPublicKey

java.lang.Object

iaik.x509.PublicKeyInfo

iaik.security.ec.common.AbstractECPublicKey

iaik.security.ec.common.ECPublicKey

All Implemented Interfaces:

iaik.asn1.ASN1Type, Serializable, Cloneable, ECKey, ECPublicKey, Key, PublicKey

public final class ECPublicKey
extends AbstractECPublicKey

Representation of a public key for EC algorithms and implementation of the ECPublicKey interface. It is derived from PublicKeyInfo which makes it suitable for use in X.509 certificates.

References:

[1] ANSI X9.62-2005, "American National Standard for Financial Services - The Elliptic Curve Digital Signature Algorithm (ECDSA)", ASC X9, November 2005.

[2] NIST SP 56A, "Recommendation for Pair-Wise Key Establishment Schemes Using Discrete Logarithm Cryptography", May 2013

Author:

Christian Hanser, Sebastian Ramacher

See Also:

ECKeyPairGenerator, ECKey, ECPrivateKey, ECPublicKeySpec, ECPrivateKeySpec, Serialized Form

Field Summary

Fields inherited from class iaik.security.ec.common.AbstractECPublicKey

encodedPublicKey_, params_, w_

Fields inherited from class iaik.x509.PublicKeyInfo

public_key_algorithm

Constructor Summary

Constructors

Constructor and Description
ECPublicKey(iaik.asn1.ASN1Object keyObj) Creates a new public key from an ASN.1 Object.
ECPublicKey(byte[] encoded) Creates a new public key from an ASN.1 encoded DER byte array.
ECPublicKey(ECParameterSpec params, ECPoint w) Creates a new public key object.
ECPublicKey(ECPublicKey key) Creates a new public key object from a key.
ECPublicKey(ECPublicKeySpec key) Creates a new public key object from a spec.
ECPublicKey(ECPublicKeySpec key) Creates a new public key object from a spec.
ECPublicKey(InputStream is) Reads the DER or BER encoded public key info from an input stream.

Method Summary

Modifier and Type	Method and Description
protected void	createEncodedPublicKey() Creates the ASN.1 public key structure following [1, Section E.9].
protected void	decode(byte[] publicKey)
boolean	equals(Object obj)
String	getAlgorithm()
int	getKeyLength() Returns the key length of this ECKey.
static boolean	isFullCheckEnabled() Deprecated. Use ECCelerate.isNISTSP56AFullCheckEnabled() instead.
boolean	isValid() Determines whether this public key is valid according to [2, Section 5.6.2].
static ECPublicKey	parse(byte[] publicKey) This method parses an EC public key.
static void	setFullCheckEnabled(boolean enable) Deprecated. Use ECCelerate.setNISTSP56AFullCheckEnabled(boolean) instead.
String	toString()

Methods inherited from class iaik.security.ec.common.AbstractECPublicKey

encode, getParams, getW, hashCode

Methods inherited from class iaik.x509.PublicKeyInfo

clone, createPublicKeyInfo, decode, getAlgorithmID, getEncoded, getFingerprint, getFormat, getPublicKey, getPublicKey, getPublicKey, getPublicKey, getPublicKey, getPublicKey, toASN1Object, writeTo

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.security.Key

getEncoded, getFormat

Constructor Detail

ECPublicKey

public ECPublicKey(iaik.asn1.ASN1Object keyObj)
            throws InvalidKeyException

Creates a new public key from an ASN.1 Object.

Parameters:

keyObj - the ASN.1 object holding the public key information

Throws:

InvalidKeyException - if the given ASN1Object does not hold a valid EC public key

ECPublicKey

public ECPublicKey(byte[] encoded)
            throws InvalidKeyException

Creates a new public key from an ASN.1 encoded DER byte array.

Parameters:

encoded - the byte array

Throws:

InvalidKeyException - thrown if the given encoded key could not be decoded

ECPublicKey

public ECPublicKey(ECParameterSpec params,
                   ECPoint w)

Creates a new public key object.

Parameters:

params - the domain parameters of the elliptic curve

w - the point on the elliptic curve, satisfying W = s*G

ECPublicKey

public ECPublicKey(ECPublicKeySpec key)

Creates a new public key object from a spec.

Parameters:

key - the key material

ECPublicKey

public ECPublicKey(ECPublicKey key)
            throws InvalidCurveParameterSpecException

Creates a new public key object from a key.

Parameters:

key - the key

Throws:

InvalidCurveParameterSpecException - if the curve parameter validation failed

ECPublicKey

public ECPublicKey(ECPublicKeySpec key)
            throws InvalidCurveParameterSpecException

Creates a new public key object from a spec.

Parameters:

key - the key material

Throws:

InvalidCurveParameterSpecException - if the curve parameter validation failed

ECPublicKey

public ECPublicKey(InputStream is)
            throws IOException,
                   InvalidKeyException

Reads the DER or BER encoded public key info from an input stream.

Parameters:

is - the input stream providing the data

Throws:

InvalidKeyException - if the provided key data is invalid

IOException - if the I/O error occurs

Method Detail

createEncodedPublicKey

protected void createEncodedPublicKey()

Creates the ASN.1 public key structure following [1, Section E.9].

 ECPoint ::= OCTET STRING
 

Specified by:

createEncodedPublicKey in class AbstractECPublicKey

getAlgorithm

public String getAlgorithm()

Specified by:

getAlgorithm in interface Key

Specified by:

getAlgorithm in class iaik.x509.PublicKeyInfo

decode

protected void decode(byte[] publicKey)
               throws InvalidKeyException

Specified by:

decode in class iaik.x509.PublicKeyInfo

Throws:

InvalidKeyException

parse

public static ECPublicKey parse(byte[] publicKey)
                         throws InvalidKeyException

This method parses an EC public key. The format must be ECPublicKey as defined in [1].

Parameters:

publicKey - a "RAW" EC public key

Returns:

the public key

Throws:

InvalidKeyException - if the given key is not an EC public key

setFullCheckEnabled

@Deprecated
public static void setFullCheckEnabled(boolean enable)

Deprecated. Use ECCelerate.setNISTSP56AFullCheckEnabled(boolean) instead.

Allows the user decide, whether an EC public key should be fully verified or not. Note: performing full checks is recommended to provide comprehensive security, but slows down the performance of operations, such as ECDSA verification.

Parameters:

enable - if true full key checks will be performed

isFullCheckEnabled

@Deprecated
public static boolean isFullCheckEnabled()

Deprecated. Use ECCelerate.isNISTSP56AFullCheckEnabled() instead.

Returns true, if the full key check is enabled.

Returns:

true, if the full key check is enabled

toString

public String toString()

Overrides:

toString in class iaik.x509.PublicKeyInfo

isValid

public boolean isValid()

Determines whether this public key is valid according to [2, Section 5.6.2]. ECCelerate.isNISTSP56AFullCheckEnabled() determines whether the check is performed according to [2, Section 5.6.2.3.2] or [2, Section 5.6.2.3.3].

Specified by:

isValid in class AbstractECPublicKey

Returns:

true, iff the public key could be validated

getKeyLength

public int getKeyLength()

Description copied from interface: ECKey

Returns the key length of this ECKey.

Returns:

the key length in bits

equals

public boolean equals(Object obj)

Overrides:

equals in class AbstractECPublicKey