到目前为止,我一直在使用库来处理OAuth,但最近我一直在深入挖掘,试图理解底层的OAuth流程.目前,我正在尝试使用OAuth 1.0a使用以下简单代码连接到Tumblr API v2：

import urllib,urllib2,time,random,hmac,base64,hashlib

def makenonce():
    random_number = ''.join( str( random.randint( 0,9 ) ) for _ in range( 40 ) )
    m = hashlib.md5( str( time.time() ) + str( random_number ) )
    return m.hexdigest()

def encodeparams(s):
    return urllib.quote( str( s ),safe='~' )

# Actual key and secret from a test app created using a dummy Tumblr account
consumer_key = '97oAujQhSaQNv4XDXzCjdZlOxwNyhobmDwmueJBCHWsFFsW7Ly'
consumer_secret = '5q1dpF659SOgSUb0Eo52aAyoud8N8QOuJu6enCG92aDR6WoMlf'

#oauth URLs
request_tokenURL = 'http://www.tumblr.com/oauth/request_token'

#oauth params
oauth_parameters = {
            'oauth_consumer_key'     : consumer_key,'oauth_nonce'            : makenonce(),'oauth_timestamp'        : str(int(time.time())),'oauth_signature_method' : "HMAC-SHA1",'oauth_version'          : "1.0"
            }

normalized_parameters = encodeparams( '&'.join( ['%s=%s' % ( encodeparams( str( k ) ),encodeparams( str( oauth_parameters[k] ) ) ) for k in sorted( oauth_parameters )] ) )
# Since I'm focusing only on getting the request token for now,I set this to POST.
normalized_http_method = 'POST'
normalized_http_url = encodeparams( request_tokenURL )
signature_base_string = '&'.join( [normalized_http_method,normalized_http_url,normalized_parameters] )
oauth_key = consumer_secret + '&'
hashed = hmac.new( oauth_key,signature_base_string,hashlib.sha1 )
oauth_parameters['oauth_signature'] = base64.b64encode( hashed.digest() )
oauth_header = 'Authorization: OAuth realm="http://www.tumblr.com",' + 'oauth_nonce="' + oauth_parameters['oauth_nonce'] + '",' + 'oauth_timestamp="' + oauth_parameters['oauth_timestamp'] + '",' + 'oauth_consumer_key="' + oauth_parameters['oauth_consumer_key'] + '",' + 'oauth_signature_method="HMAC-SHA1",oauth_version="1.0",oauth_signature="' + oauth_parameters['oauth_signature'] +'"'

# sample oauth_header generated by the code above:
# Authorization: OAuth realm="http://www.tumblr.com",oauth_nonce="c200a0e06f30b84b851ac3e99a71054b",oauth_timestamp="1315231855",oauth_consumer_key="97oAujQhSaQNv4XDXzCjdZlOxwNyhobmDwmueJBCHWsFFsW7Ly",oauth_signature_method="HMAC-SHA1",oauth_signature="kVAlmwolCX0WJIvTF9MB2UV5rnU="


req = urllib2.Request( request_tokenURL )
req.add_header( 'Authorization',oauth_header )
# If all goes well,Tumblr should send me the oauth request token.
print urllib2.urlopen( req ).read()

Tumblr返回HTTP错误401：未授权,而不是OAuth请求令牌.

我尝试过的事情没有取得任何成功：

>将oauth_version从“1.0”更改为“1.0a”,然后再将其更改回来.
>关于OAuth的指南要求添加’&’在consumer_secret的末尾获取oauth_key.我尝试删除’&’稍后看看是否有任何区别.
>检查OAuth参数是否已排序,它们是否已排序.
>没有将字符串“Authorization：”添加到oauth_header,然后将其添加回来.两者都没有任何区别.

我哪里出错了？