京东云 OpenAPI 签名机制的 Python 实现

摘要：京东云是将京东云所有资源的管理能力通过的方式提供出来，供京东云用户和合作伙伴使用。是京东云控制台的有效补充，方便用户更灵活的控制自己的云上资源。在开始调用京东云之前，需提前在京东云用户中心账户管理下的管理页面申请和密钥对简称。

京东云OpenAPI是将京东云所有资源的管理能力通过API的方式提供出来，供京东云用户和合作伙伴使用。OpenAPI是京东云控制台的有效补充，方便用户更灵活的控制自己的云上资源。

本文档通过step-by-step生成签名以及完整HTTP请求，并将请求发送至京东公共OpenAPI并得到response。

京东云：www.jdcloud.com
京东云OpenAPI：docs.jdcloud.com/cn/?act=3
公共说明：docs.jdcloud.com/cn/common-declaration/api/introduction

要使用某个产品线的OpenAPI，首先需要先通过产品文档了解产品功能、计费等方面的信息。

在开始调用京东云OpenAPI之前，需提前在京东云用户中心账户管理下的AccessKey管理页面申请AccessKey和SecretKey密钥对（简称AK/SK）。AK/SK信息请妥善保管，如果遗失可能会造成非法用户使用此信息操作您在云上的资源，给你造成数据和财产损失。AK/SK密钥对允许启用、禁用，启用后可用其调用OpenAPI，禁用后不能用其调用OpenAPI。

京东云OpenAPI使用Restful接口风格，要进行OpenAPI调用需要包含如下信息：请求协议，请求方式，请求地址，请求路径，请求头，请求参数，请求体。

为了您的数据安全，建议务必使用https协议。

初始基本配置

生成初始请求header

生成标准请求串

生成待签名字符串

生成签名key

计算签名值

更新请求头

发送请求

# GET请求
method = "GET"
# 地域
region = "cn-north-1"
# 产品线
service = "vm"
# vm产品线服务地址：{product}.jdcloud-api.com
full_host = "vm.jdcloud-api.com"

# OpenAPI服务的地址和路径格式一般为（默认为https）：
# https://{product}.jdcloud-api.com/{API版本号}/regions/{地域ID}/{资源名称}/{资源ID(可选)}/{子资源名称(可选)}/{子资源ID(可选)}{:自定义动作(可选)}
url = "https://vm.jdcloud-api.com/v1/regions/cn-north-1/instances/i-uvvtdzuxre"

# 规范请求路径Path：/{apiVersion}/regions/{regionId}/instances/{instanceId}
canonical_uri = "/v1/regions/cn-north-1/instances/i-uvvtdzuxre"

# 本例中为GET请求，body为空（若为PUT/POST/PATCH请求，则body为parameter的JSON格式）
body = ""

# 当前时间
now = datetime.datetime.utcfromtimestamp(time.time())

# 格式化字符串为："20180812T074253Z"
jdcloud_date = now.strftime("%Y%m%dT%H%M%SZ")

# 生成datestamp字符串：“20180812”，用于签名
datestamp = now.strftime("%Y%m%d")

# 随机生成的字符串：“58542f21-bda3-4736-9a08-da2339669e52”
nonce = str(uuid.uuid4())

# 增加请求header字段：
# Content-Type：请求数据格式为JSON
# User-Agent：格式为“JdcloudSdkPython/ <产品线>/<产品线revision>”
# 请求头如下：
#         {"x-jdcloud-nonce": "63e0148e-0fef-4c78-9228-47fefe470b07", 
#         "Content-Type": "application/json", 
#         "x-jdcloud-date": "20180812T094103Z", 
#         "User-Agent": "JdcloudSdkPython/1.2.1 vm/1.0.0"}
headers = {"Content-Type": "application/json", "User-Agent": "JdcloudSdkPython/1.2.1 vm/1.0.0"}
headers["x-jdcloud-date"] = jdcloud_date
headers["x-jdcloud-nonce"] = nonce

# 生成请求查询字符串，本例为空。
canonical_querystring = ""

# 生成CanonicalHeaders字符串，CanonicalHeaders为需要参与签名的请求头及值。要创建规范 HTTP header 列表，请将所有 HTTP header 名称转换为小写，并删除前导空格和尾随空格。通过用字符代码排序HTTP header ，然后遍历 HTTP header 名称来构建规范 HTTP header 列表。使用:分隔名称和值，并添加换行符。
# 如下：
#         content-type:application/json
#         host:vm.jdcloud-api.com
#         x-jdcloud-date:20180812T074253Z
#         x-jdcloud-nonce:58542f21-bda3-4736-9a08-da2339669e52
#
canonical_headers = "content-type" + ":" + headers["Content-Type"] + "
" + "host" + ":" + full_host + "
" + "x-jdcloud-date" + ":" + headers["x-jdcloud-date"] + "
" + "x-jdcloud-nonce" + ":" + headers["x-jdcloud-nonce"] + "
"

# SignedHeaders用于告知京东云，请求中的哪些头是签名过程的一部分，京东云可以忽略哪些头（例如，由代理添加的任何附加标头），以验证请求。注意host, x-jdcloud-date, x-jdcloud-nonce必须包含在内。
signed_headers = "content-type;host;x-jdcloud-date;x-jdcloud-nonce"

# 生成body的hash（即使body为空字符串）： 
#        “e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855”
payload_hash = hashlib.sha256(body.encode("utf-8")).hexdigest()

# 生成标准请求串：
# GET
# /v1/regions/cn-north-1/instances/i-uvvtdzuxre
# 
# content-type:application/json
# host:vm.jdcloud-api.com
# x-jdcloud-date:20180812T074253Z
# x-jdcloud-nonce:58542f21-bda3-4736-9a08-da2339669e52
# content-type;host;x-jdcloud-date;x-jdcloud-nonce
#
# e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
canonical_request = (method + "
" +
                     canonical_uri + "
" +
                     canonical_querystring + "
" +
                     canonical_headers + "
" +
                     signed_headers + "
" +
                     payload_hash)

# 用于创建请求签名的哈希算法，目前只支持 `JDCLOUD2-HMAC-SHA256`
algorithm = "JDCLOUD2-HMAC-SHA256"

# CredentialScope格式为”{时间}/{地域编码}/{产品线}/jdcloud2_request
”，例如20180130/cn-north-1/vpc/jdcloud2_request

# "20180812/cn-north-1/vm/jdcloud2_request"
credential_scope = (datestamp + "/" + region + "/" + service + "/" + "jdcloud2_request")

# 生成canonical_request的哈希值
#         a3349e006302711650240165d89bb9c0b504ff8dc95d665cd98907877fbbd423
canonical_request_hash = hashlib.sha256(canonical_request.encode("utf-8")).hexdigest()

# 生成待签名字符串：
#  StringToSign =
#         Algorithm + 
 +
#         RequestDateTime + 
 +
#         CredentialScope + 
 +
#         HashedCanonicalRequest
# 结果为：
# JDCLOUD2-HMAC-SHA256
# 20180812T074253Z
# 20180812/cn-north-1/vm/jdcloud2_request
# a3349e006302711650240165d89bb9c0b504ff8dc95d665cd98907877fbbd423

string_to_sign = algorithm + "
" + jdcloud_date + "
" + credential_scope + "
" + canonical_request_hash

# 计算签名key（二进制），其中HMAC(key, data)代表以二进制格式返回输出的HMAC-SHA256函数
# 伪代码：
# kSecret = your secret access key
# kDate = HMAC("JDCLOUD2" + kSecret, Date)
# kRegion = HMAC(kDate, Region)
# kService = HMAC(kRegion, Service)
# kSigning = HMAC(kService, "jdcloud2_request")

k_date = hmac.new(("JDCLOUD2" + secret_key).encode("utf-8"), datestamp.encode("utf-8"), hashlib.sha256).digest()

k_region = hmac.new(k_date, region.encode("utf-8"), hashlib.sha256).digest()

k_service = hmac.new(k_region, service.encode("utf-8"), hashlib.sha256).digest()

signing_key = hmac.new(k_service, "jdcloud2_request".encode("utf-8"), hashlib.sha256).digest()

# 最终生成签名：
#     如：9b2026198d3acbf99da395e23a994ed369a0d70f5b4a5d7567dd0caf3009656d
encoded = string_to_sign.encode("utf-8")
signature = hmac.new(signing_key, encoded, hashlib.sha256).hexdigest()

# 计算签名后，需要将签名的结果作为Authorization请求头将其添加到请求中
# "JDCLOUD2-HMAC-SHA256 Credential=xxxxxxxxxxxxxxxxxxxxxxxxxxx/20180812/cn-north-1/vm/jdcloud2_request, SignedHeaders=content-type;host;x-jdcloud-date;x-jdcloud-nonce, Signature=53305ed8290a26493beec3060d9b1ff7d94cb1a6f2171cd193a1562814c8de37"
authorization_header = algorithm + " " + "Credential=" + access_key + "/" + credential_scope + ", " + "SignedHeaders=" + signed_headers + ", " + "Signature=" + signature

# 更新请求headers，如下：
#        {"x-jdcloud-date": "20180812T074253Z", 
#        "x-jdcloud-content-sha256": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855", 
#        "JDCLOUD2-HMAC-SHA256": "JDCLOUD2-HMAC-SHA256", 
#        "x-jdcloud-nonce": "58542f21-bda3-4736-9a08-da2339669e52", 
#        "User-Agent": "JdcloudSdkPython/1.2.1 vm/1.0.0", 
#        "Content-Type": "application/json", 
#        "Authorization": "JDCLOUD2-HMAC-SHA256 Credential=xxxxxxxxxxxxxxxxxxxxxxxxxxx/20180812/cn-north-1/vm/jdcloud2_request, SignedHeaders=content-type;host;x-jdcloud-date;x-jdcloud-nonce, Signature=53305ed8290a26493beec3060d9b1ff7d94cb1a6f2171cd193a1562814c8de37"}

headers["Authorization"] = authorization_header
headers["x-jdcloud-date"] = jdcloud_date
headers["x-jdcloud-content-sha256"] = payload_hash
headers["JDCLOUD2-HMAC-SHA256"] = "JDCLOUD2-HMAC-SHA256"
headers["x-jdcloud-nonce"] = nonce

# Python发送请求，并获得相应
resp = requests.request(method, url, data=body, headers=headers)

请求头中必须包含SignedHeaders中的各个字段：

# curl -X GET -H "x-jdcloud-date:20180812T094103Z" -H "x-jdcloud-nonce:63e0148e-0fef-4c78-9228-47fefe470b07" -H "Content-Type:application/json" -H "Authorization:JDCLOUD2-HMAC-SHA256 Credential=xxxxxxxxxxxxxxxxxxxxxxxxxxx/20180812/cn-north-1/vm/jdcloud2_request, SignedHeaders=content-type;host;x-jdcloud-date;x-jdcloud-nonce, Signature=53305ed8290a26493beec3060d9b1ff7d94cb1a6f2171cd193a1562814c8de37" https://vm.jdcloud-api.com/v1/regions/cn-north-1/instances/i-uvvtdzuxre

可将发送OpenAPI请求简单总结为：

生成待签名字符串（包含header各个字段、body的hash等）

生成签名key（包含SK并多层加盐）；

用key签名step 1的待签名字符串，将签名信息加入到header并发送请求（包含AK），服务端按照同样的方式可以校验身份。

from jdcloud_sdk.core.credential import *
from jdcloud_sdk.services.vm.client.VmClient import *
from jdcloud_sdk.services.vm.apis.DescribeInstanceRequest import *
import json
# 用户AK&SK
access_key = ""
secret_key = ""
# 地域
regionId = "cn-north-1"
# 要查询的实例ID
instanceId = "i-uvvtdzuxre"
# 生成Credential和Client
myCredential = Credential(access_key, secret_key)
myClient = VmClient(myCredential)
# 定义参数
myParam = DescribeInstanceParameters(regionId, instanceId)
# 定义请求
myRequest = DescribeInstanceRequest(myParam)
# Client发送请求，并得到响应
resp = myClient.send(myRequest)
# 将返回结果以JSON格式打印
print json.dumps(resp.result, indent=2)