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PHP Extension

Get EC Public Key from EC Private Key

See more ECC Examples

Demonstrates how to get an EC public key from an EC private key.

Chilkat PHP Extension Downloads

PHP Extension
<?php

include("chilkat.php");

$success = false;

// We have an ECC private key...
// The contents of the private key PEM file look like this:

// 	-----BEGIN PRIVATE KEY-----
// 	MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQg3J8q/24D1sEKGdP9
// 	72MGYElLGpw/a56Y3t6pfON3uhShRANCAATlSmoizyhAwoYZAOuFBATl07/1RR54
// 	a1Dzfm16grxJe666AGKR+bSs24hk7TEpaeCTvT8YOOM3l+xKFg7zq6Q9
// 	-----END PRIVATE KEY-----

$privKey = new CkPrivateKey();
$success = $privKey->LoadPemFile('qa_data/ecc/secp256r1-key-pkcs8.pem');
if ($success == false) {
    print $privKey->lastErrorText() . "\n";
    exit;
}

// Get the public key.
$pubKey = new CkPublicKey();
$privKey->ToPublicKey($pubKey);

// Save the public key to a PEM file.
$success = $pubKey->SavePemFile(false,'qa_data/ecc/secp256r1-pubkey.pem');
if ($success == false) {
    print $pubKey->lastErrorText() . "\n";
    exit;
}

// The contents of the ECC public key PEM file look like this:

// 	-----BEGIN PUBLIC KEY-----
// 	MIIBSzCCAQMGByqGSM49AgEwgfcCAQEwLAYHKoZIzj0BAQIhAP////8AAAABAAAA
// 	AAAAAAAAAAAA////////////////MFsEIP////8AAAABAAAAAAAAAAAAAAAA////
// 	///////////8BCBaxjXYqjqT57PrvVV2mIa8ZR0GsMxTsPY7zjw+J9JgSwMVAMSd
// 	NgiG5wSTamZ44ROdJreBn36QBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt6zOg9KE5
// 	RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA
// 	//////////+85vqtpxeehPO5ysL8YyVRAgEBA0IABOVKaiLPKEDChhkA64UEBOXT
// 	v/VFHnhrUPN+bXqCvEl7rroAYpH5tKzbiGTtMSlp4JO9Pxg44zeX7EoWDvOrpD0=
// 	-----END PUBLIC KEY-----

print 'Success.' . "\n";

?>