I am currently interacting with the Twitter API using the OAuth protocol and writing code in Python. Like most users, I find that the most difficult part of the specs is related to signatures.
After wandering around the net in search of a solution, I decided to go to my own code to better understand what was going on.
For other users, I am posting here a very simple and short implementation of the SHA1 signature specifications in Python:
import hmac
from hashlib import sha1
from urllib import quote, urlencode
from base64 import b64encode
from urlparse import urlparse
def sign_request_sha1(url,method,data,secret=""):
pu = urlparse(urlparse(url).geturl())
normUrl = "%s://%s%s%s" % (
pu.scheme,
pu.hostname,
"" if not pu.port or {"http":80,"https":443}[pu.scheme] == pu.port else ":%d" % pu.port,
pu.path,
)
names = data.keys()
names.sort()
sig = "%s&%s&%s" % (
method.upper(),
quote(normUrl,''),
quote("&".join(["%s=%s" % (k,quote(data[k].encode('utf-8'),'')) for k in names]),''),
)
key = "%s&%s" % (quote(CONSUMER_SECRET.encode('utf-8'),''),secret)
return b64encode(hmac.new(key,sig,sha1).digest())
The input parameters of the function are:
- url: URL to which you are going to invoke a specific OAuth request.
- method: it should be "GET" or "POST" depending on how you are going to send your request.
- : , , , "oauth_signature" ( ).
- secret: , .
Twitter , , , , ..
, , " ":
from random import getrandbits
from base64 import b64encode
from time import time
def twitter_request_token(req,callback,errback):
req_url="http://twitter.com:80/oauth/request_token"
data = { \
"oauth_consumer_key" : CONSUMER_KEY,
"oauth_nonce" : b64encode("%0x" % getrandbits(256))[:32],
"oauth_timestamp" : str(int(time())),
"oauth_signature_method" : "HMAC-SHA1",
"oauth_version" : "1.0",
"oauth_callback" : "http://localhost:8080/",
}
data["oauth_signature"] = sign_request_sha1(req_url,"GET",data)
.