# Poco::Crypto

# class ECKeyImpl

Library: Crypto
Package: EC
Header: Poco/Crypto/ECKeyImpl.h

## Description

Elliptic Curve key clas implementation.

## Inheritance

Direct Base Classes: KeyPairImpl

All Base Classes: KeyPairImpl, Poco::RefCountedObject

## Member Summary

Member Functions: getCurveNID, getCurveName, getECKey, groupId, groupName, hasCurve, save, size

Inherited Functions: duplicate, name, referenceCount, release, save, size, type

## Types Aliases

### ByteVec

using ByteVec = std::vector < unsigned char >;

### Ptr

using Ptr = Poco::AutoPtr < ECKeyImpl >;

## Constructors

### ECKeyImpl

ECKeyImpl(
const EVPPKey & key
);

Constructs ECKeyImpl by extracting the EC key.

### ECKeyImpl

ECKeyImpl(
const X509Certificate & cert
);

Constructs ECKeyImpl by extracting the EC public key from the given certificate.

### ECKeyImpl

ECKeyImpl(
const PKCS12Container & cert
);

Constructs ECKeyImpl by extracting the EC private key from the given certificate.

### ECKeyImpl

ECKeyImpl(
int eccGroup
);

Creates the ECKey of the specified group. Creates a new public/private keypair using the given parameters. Can be used to sign data and verify signatures.

### ECKeyImpl

ECKeyImpl(
const std::string & publicKeyFile,
const std::string & privateKeyFile,
const std::string & privateKeyPassphrase
);

Creates the ECKey, by reading public and private key from the given files and using the given passphrase for the private key. Can only by used for signing if a private key is available.

### ECKeyImpl

ECKeyImpl(
std::istream * pPublicKeyStream,
std::istream * pPrivateKeyStream,
const std::string & privateKeyPassphrase
);

Creates the ECKey. Can only by used for signing if pPrivKey is not null. If a private key file is specified, you don't need to specify a public key file. OpenSSL will auto-create it from the private key.

## Destructor

### ~ECKeyImpl

~ECKeyImpl();

Destroys the ECKeyImpl.

## Member Functions

### getCurveNID

static int getCurveNID(
std::string & name
);

Returns the NID of the specified curve.

If name is empty, returns the first curve NID and updates the name accordingly.

### getCurveName

static std::string getCurveName(
int nid = - 1
);

Returns elliptical curve name corresponding to the given nid; if nid is not found, returns empty string.

If nid is -1, returns first curve name.

If no curves are found, returns empty string;

### getECKey

EC_KEY * getECKey();

Returns the OpenSSL EC key.

### getECKey

const EC_KEY * getECKey() const;

Returns the OpenSSL EC key.

### groupId

int groupId() const;

Returns the EC key group integer Id.

### groupName

std::string groupName() const;

Returns the EC key group name.

### hasCurve

static bool hasCurve(
const std::string & name
);

Returns true if the named curve is found, false otherwise.

### save

void save(
const std::string & publicKeyFile,
const std::string & privateKeyFile = "",
const std::string & privateKeyPassphrase = ""
) const;

Exports the public and private keys to the given files.

If an empty filename is specified, the corresponding key is not exported.

See also: Poco::Crypto::KeyPairImpl::save()

### save

void save(
std::ostream * pPublicKeyStream,
std::ostream * pPrivateKeyStream = nullptr,
const std::string & privateKeyPassphrase = ""
) const;

Exports the public and private key to the given streams.

If a null pointer is passed for a stream, the corresponding key is not exported.

See also: Poco::Crypto::KeyPairImpl::save()

### size

int size() const;

Returns the EC key length in bits.

See also: Poco::Crypto::KeyPairImpl::size()