How can i get publickey from pem file which is created based on rsa 364. installed crypt(RSA.php) library still getting below error

Fatal error: Call to undefined method Crypt_RSA::loadKey() in C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\rsa.php

$file = "C:\key_file.pem"; 
$keypair = Crypt_RSA_KeyPair::fromPEMString(file_get_contents($file));
$public_key = $keypair->getPublicKey(); 
$rsa_pub_key = Crypt_RSA_Key::fromString($public_key->toString()); 
$rsa_obj = new Crypt_RSA; 
$verify_status = $rsa_obj->validateSign($text,$recieved_signed_sign, $rsa_pub_key) ? 'valid' : 'invalid'; 

Fatal error: Call to undefined method PEAR_Error::getPublicKey() in C:\Program Files\xxxx\rsa.php gibi hata alıyorum

Tried same thing openssl_verify. verify is rturning 0 Trying to verify sign received with base64_encode with 384 rsa key.

**$base64DecodedStr = base64_decode("A1a0o8JzF7q12Sr4gJvYjslhg5XVA2fWy28.JyohJ05uyiZGyBpqazqb");
$status = openssl_verify($msg,$base64DecodedStr,$pub_key);**

Bana bu sorunu çözmek için yardımcı olun. Çok teşekkürler.