/**
* Adds a key to the key set.
*
* This function checks whether an identical key (whether by key ID or by
* key contents) already exists in the key set.
*
* @param Key $key the key to add
* @throws KeyException if there is an identical key
*/
function add($key)
{
$signature = $key->getSignature();
foreach ($this->keys as $existing_key) {
if ($existing_key->getSignature() == $signature) {
throw new KeyException('Key already exists');
}
if ($existing_key->getKeyID() == $key->getKeyID()) {
throw new KeyException('Key already exists');
}
}
$this->keys[] = $key;
}
