I have same problem but for auto generate time and nonce you can do this:
<?php
$nonce = md5(mt_rand());
// Set headers
curl_setopt($ch, CURLOPT_HTTPHEADER, ['
Authorization: OAuth oauth_consumer_key="zfksKSt8m7Bk",
oauth_nonce=".$nonce.",
oauth_signature="%2BOy0fDsKilNymYOOZRqjJN5q3tg%3D",
oauth_signature_method="HMAC-SHA1",
oauth_timestamp='.time().',
oauth_token="IG6x6jIjboVhmyzFtjzn1fGT",
oauth_version="1.0"
',
'Content-Type: application/json; charset=utf-8',
]
);
I’m study for generate signature. I think It Can Be Useful To generate the signature using something like
$signature = hash_hmac( 'sha1', $base_string, $key );