com.entrust.toolkit.security.crypto.ec

Enum EcParameterFormat

java.lang.Object

java.lang.Enum<EcParameterFormat>

com.entrust.toolkit.security.crypto.ec.EcParameterFormat

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<EcParameterFormat>

public enum EcParameterFormat
extends java.lang.Enum<EcParameterFormat>

Identifiers for the various EC domain parameter formats that are supported.

Since:

8.0

Enum Constant Summary

Enum Constants

Enum Constant and Description
implicitCA The 'implicitCA' EC domain parameter format.
named The 'named' EC domain parameter format.
specified The 'specified' EC domain parameter format.

Method Summary

Modifier and Type	Method and Description
static EcParameterFormat	valueOf(java.lang.String name) Returns the enum constant of this type with the specified name.
static EcParameterFormat[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

specified

public static final EcParameterFormat specified

The 'specified' EC domain parameter format.

With this format, all of the EC domain parameter values (i.e. curve, base point, order, and cofactor) are explicitly encoded. The size of the resulting encoded EC domain parameters is much larger when using this format as compared to the other formats, but this format has the benefit of being the most widely interoperable. Most third party products that support EC will support some set of 'named' EC domain parameters and also support 'specified' EC domain parameters. If such a product is encountered that does not support all of the 'named' EC domain parameters that Entrust does, forcing an encoding in 'specified' format is one way to still achieve interoperability with this product.

It is recommended to use this EC domain parameter encoding format when using custom EC domain parameters (i.e. non-standardized EC domain parameters), or when wide interoperability is paramount. To convert a set of existing EC domain parameters to 'specified' format, use the EcParameterFactory.getSpecifiedInstance(ECParameterSpec) API. To force an EC public key or private key to use the 'specified' EC domain parameter format during an encode operation refer to the EcPublicKey.getEncoded(boolean) or EcPrivateKey.getEncoded(boolean) APIs.

named

public static final EcParameterFormat named

The 'named' EC domain parameter format.

With this format, an object identifier that uniquely identifies the set of EC domain parameter values is encoded. The size of the resulting encoded EC domain parameters is small (typically 10-20 bytes), but this format does have interoperability drawbacks. For EC domain parameters that are widely used (i.e. NIST's EC domain parameters), most products will accept this format. However, it is possible when using less common EC domain parameters, that some products reject this format.

It is recommended to use this EC domain parameter format when using any of the 'named' EC domains supported in this release (refer to the class documentation of EcParameterFactory for a list of supported named EC domains). To convert a set of existing EC domain parameters to 'named' format, use the EcParameterFactory.getNamedInstance(ECParameterSpec) API.

implicitCA

public static final EcParameterFormat implicitCA

The 'implicitCA' EC domain parameter format.

With this format, a NULL value is encoded to represent the set of EC domain parameter values. It simply indicates that the parameters are inherited from elsewhere. This size of the resulting encoding is very small (2 bytes), but this format does have severe interoperability drawbacks. Both the encoding and decoding application must have the same interpretation of which set of EC domain parameter values that 'implicitCA' refers to. In the Toolkit, this can be configured through the EcParameterFactory.setConfiguredImplicitCaParams(ECParameterSpec) API.

It is recommended to only use this EC domain parameter format in a closed environment, when one has control over both the encoding and decoding ends. To convert a set of existing EC domain parameters to 'implicitCA' format, use the EcParameterFactory.getImplicitCaInstance(ECParameterSpec) API.

Method Detail

values

public static EcParameterFormat[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (EcParameterFormat c : EcParameterFormat.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static EcParameterFormat valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null