Perl Requires Chilkat v11.0.0+

How to Generate an Elliptic Curve Shared Secret

See more ECC Examples

Demonstrates how to generate an ECC (Elliptic Curve Cryptography) shared secret. Imagine a cilent has one ECC private key, the server has another. A shared secret is computed by each side providing it's public key to the other. The private keys are kept private. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

# This example includes both client-side and server-side code.
# Each code segment is marked as client-side or server-side.
# Imagine these segments are running on separate computers...

# -----------------------------------------------------------------
# (Client-Side) Generate an ECC key, save the public part to a file.
# -----------------------------------------------------------------
my $prngClient = Chilkat2::Prng->new;
my $eccClient = Chilkat2::Ecc->new;
my $privKeyClient = Chilkat2::PrivateKey->new;
my $success = $eccClient->GenKey('secp256r1', $prngClient, $privKeyClient);
if (!$success) {
    print $eccClient->LastErrorText, "\n";
    exit;
}

my $pubKeyClient = Chilkat2::PublicKey->new;
$privKeyClient->ToPublicKey($pubKeyClient);
$pubKeyClient->SavePemFile(0, 'qa_output/eccClientPub.pem');

# -----------------------------------------------------------------
# (Server-Side) Generate an ECC key, save the public part to a file.
# -----------------------------------------------------------------
my $prngServer = Chilkat2::Prng->new;
my $eccServer = Chilkat2::Ecc->new;
my $privKeyServer = Chilkat2::PrivateKey->new;
$eccServer->GenKey('secp256r1', $prngServer, $privKeyServer);

my $pubKeyServer = Chilkat2::PublicKey->new;
$privKeyServer->ToPublicKey($pubKeyServer);
$pubKeyServer->SavePemFile(0, 'qa_output/eccServerPub.pem');

# -----------------------------------------------------------------
# (Client-Side) Generate the shared secret using our private key, and the other's public key.
# -----------------------------------------------------------------

# Imagine that the server sent the public key PEM to the client.
# (This is simulated by loading the server's public key from the file.
my $pubKeyFromServer = Chilkat2::PublicKey->new;
$pubKeyFromServer->LoadFromFile('qa_output/eccServerPub.pem');
my $sharedSecret1 = $eccClient->SharedSecretENC($privKeyClient, $pubKeyFromServer, 'base64');

# -----------------------------------------------------------------
# (Server-Side) Generate the shared secret using our private key, and the other's public key.
# -----------------------------------------------------------------

# Imagine that the client sent the public key PEM to the server.
# (This is simulated by loading the client's public key from the file.
my $pubKeyFromClient = Chilkat2::PublicKey->new;
$pubKeyFromClient->LoadFromFile('qa_output/eccClientPub.pem');
my $sharedSecret2 = $eccServer->SharedSecretENC($privKeyServer, $pubKeyFromClient, 'base64');

# ---------------------------------------------------------
# Examine the shared secrets.  They should be the same.
# Both sides now have a secret that only they know.
# ---------------------------------------------------------
print $sharedSecret1, "\n";
print $sharedSecret2, "\n";