OSS 允许在 Header 中包含签名或在 URL 中包含签名，这两种签名方式的区别如下：

Header	URL
不支持设置 expires	支持设置 expires
常用 Method 包括： GET、POST、PUT、DELETE	常用 Method 包括：GET、PUT
date 时间是 GMT 格式	date 替换成 expires 变成时间戳
signature 不需要 URL 编码	signature 需要 URL 编码

通过在 Header 或 URL 中自签名计算 signature 时， 经常遇到签名失败，报错 “The request signature we calculated does not match the signature you provided” 。以下 demo 演示了如何调用 API 自签名时上传 Object 到 OSS。

#! /us/bin/envy python
#Author: hanli
#Update: 2018-09-29

from optparse import OptionParser
import urllib, urllib2
import datetime
import base64
import hmac
import sha
import os
import sys
import time


class Main():
  
  # Initial input parse

  def __init__(self,options):

    self.ak = options.ak
    self.sk = options.sk
    self.ed = options.ed
    self.bk = options.bk
    self.fi = options.fi
    self.oj = options.objects
    self.left = '\033[1;31;40m'
    self.right = '\033[0m'
    self.types = "application/x-www-form-urlencoded"    
    self.url = 'http://{0}.{1}/{2}'.format(self.bk,self.ed,self.oj)

  # Check client input parse

  def CheckParse(self):

    if (self.ak and self.sk and self.ed and self.bk and self.oj and self.fi) != None:
      if str(self.ak and self.sk and self.ed and self.bk and self.oj and self.fi):
        self.PutObject()
    else:
      self.ConsoleLog("error","Input parameters cannot be empty")

  # GET local GMT time

  def GetGMT(self):
  
    SRM = datetime.datetime.utcnow()
    GMT = SRM.strftime('%a, %d %b %Y %H:%M:%S GMT')
    
    return GMT

  # GET Signature

  def GetSignature(self):

    mac = hmac.new("{0}".format(self.sk),"PUT\n\n{0}\n{1}\n/{2}/{3}".format(self.types,self.GetGMT(),self.bk,self.oj), sha)
    Signature = base64.b64encode(mac.digest())
   
    return Signature

  # PutObject

  def PutObject(self):
   
    try: 
      with open(self.fi) as fd:
        files = fd.read()
    except Exception as e:
      self.ConsoleLog("error",e)
  
    try:
      request = urllib2.Request(self.url, files)
      request.add_header('Host','{0}.{1}'.format(self.bk,self.ed))
      request.add_header('Date','{0}'.format(self.GetGMT()))
      request.add_header('Authorization','OSS {0}:{1}'.format(self.ak,self.GetSignature()))
      request.get_method = lambda:'PUT'
      response = urllib2.urlopen(request,timeout=10)
      fd.close()
      self.ConsoleLog(response.code,response.headers)
    except Exception,e:
      self.ConsoleLog("error",e)
 
  # output error log

  def ConsoleLog(self,level=None,mess=None):

    if level == "error":
      sys.exit('{0}[ERROR:]{1}{2}'.format(self.left,self.right,mess))
    else:
      sys.exit('\nHTTP/1.1 {0} OK\n{1}'.format(level,mess))

if __name__ == "__main__":

  parser = OptionParser()
  parser.add_option("-i",dest="ak",help="Must fill in Accesskey")
  parser.add_option("-k",dest="sk",help="Must fill in AccessKeySecrety")
  parser.add_option("-e",dest="ed",help="Must fill in endpoint")
  parser.add_option("-b",dest="bk",help="Must fill in bucket")
  parser.add_option("-o",dest="objects",help="File name uploaded to oss")
  parser.add_option("-f",dest="fi",help="Must fill localfile path")

  (options, args) = parser.parse_args()
  handler = Main(options)
  handler.CheckParse()

请求头：

PUT /yuntest HTTP/1.1
Accept-Encoding: identity
Content-Length: 147
Connection: close
User-Agent: Python-urllib/2.7
Date: Sat, 22 Sep 2018 04:36:52 GMT
Host: yourBucket.oss-cn-shanghai.aliyuncs.com
Content-Type: application/x-www-form-urlencoded
Authorization: OSS B0g3mdt:lNCA4L0P43Ax

响应头：

HTTP/1.1 200 OK
Server: AliyunOSS
Date: Sat, 22 Sep 2018 04:36:52 GMT
Content-Length: 0
Connection: close
x-oss-request-id: 5BA5C6E4059A3C2F
ETag: "D0CAA153941AAA1CBDA38AF"
x-oss-hash-crc64ecma: 8478734191999037841
Content-MD5: 0MqhU5QbIp3Ujqqhy9o4rw==
x-oss-server-time: 15

通过浏览器访问时的 HTTP 抓包数据如下图所示。