iphone - got error invalid signature when requesting token -

when trying request token tripit oauth, got error invalid signature. url is:

https://api.tripit.com/oauth/request_token?oauth_consumer_key=c5676701706473430d016ac7dc58a0149333349e&oauth_consumer_secret=90b7567665605fad847815949ce414f7078742d5&oauth_signature_method=hmac-sha1&oauth_timestamp=1304072442&oauth_nonce=kllo9940pd9333jh&oauth_version=1.0

please me, wrong ???

https://api.tripit.com/oauth/request_token? oauth_consumer_key     = c5676701706473430d016ac7dc58a0149333349e& oauth_consumer_secret  = 90b7567665605fad847815949ce414f7078742d5& oauth_signature_method = hmac-sha1& oauth_timestamp        = 1304072442& oauth_nonce            = kllo9940pd9333jh& oauth_version          = 1.0 

i guess in temporary credentials step. looks kinds of wrong. shouldn't send oauth_consumer_secret not spec parameter, not sending oauth_callback, not sending oauth_signature, , sending instead post (or @ least not providing post data, can safari or firefox+firebug/livehttpheaders), unless server says otherwise (which case, don't know) wrong. anyway, answer in rfc, spent few days reading , it's fading memory.

you should try use library, or re-read rfc5849.
if want understand oauth, suggest read oauth client: https://github.com/j4n0/oauth because implementation easy follow.