Created
December 6, 2019 05:19
-
-
Save and2long/07e297948f447d5f5ef0a33a3976933b to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
# Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. | |
# | |
# This file is licensed under the Apache License, Version 2.0 (the "License"). | |
# You may not use this file except in compliance with the License. A copy of the | |
# License is located at | |
# | |
# http://aws.amazon.com/apache2.0/ | |
# | |
# This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS | |
# OF ANY KIND, either express or implied. See the License for the specific | |
# language governing permissions and limitations under the License. | |
# AWS Version 4 signing example | |
# DynamoDB API (CreateTable) | |
# See: http://docs.aws.amazon.com/general/latest/gr/sigv4_signing.html | |
# This version makes a POST request and passes request parameters | |
# in the body (payload) of the request. Auth information is passed in | |
# an Authorization header. | |
import datetime | |
import hashlib | |
import hmac | |
import sys | |
import requests # pip install requests | |
# ************* REQUEST VALUES ************* | |
method = 'POST' | |
service = 'dynamodb' | |
host = 'dynamodb.ap-northeast-1.amazonaws.com' | |
region = 'ap-northeast-1' | |
endpoint = 'https://dynamodb.ap-northeast-1.amazonaws.com/' | |
# POST requests use a content type header. For DynamoDB, | |
# the content is JSON. | |
content_type = 'application/x-amz-json-1.0' | |
# DynamoDB requires an x-amz-target header that has this format: | |
# DynamoDB_<API version>.<operationName> | |
amz_target = 'DynamoDB_20120810.GetItem' | |
# Request parameters for CreateTable--passed in a JSON block. | |
request_parameters = """ | |
{ | |
"TableName": "astrax_user", | |
"Key": { | |
"hash_key": { | |
"S": "astrax_user" | |
}, | |
"range_key": { | |
"S": "0y2sxHLasobaFvNWJBXr7PQ9vMQ2" | |
} | |
} | |
} | |
""" | |
# Key derivation functions. See: | |
# http://docs.aws.amazon.com/general/latest/gr/signature-v4-examples.html#signature-v4-examples-python | |
def sign(key, msg): | |
return hmac.new(key, msg.encode("utf-8"), hashlib.sha256).digest() | |
def getSignatureKey(key, date_stamp, regionName, serviceName): | |
kDate = sign(('AWS4' + key).encode('utf-8'), date_stamp) | |
kRegion = sign(kDate, regionName) | |
kService = sign(kRegion, serviceName) | |
kSigning = sign(kService, 'aws4_request') | |
return kSigning | |
# Read AWS access key from env. variables or configuration file. Best practice is NOT | |
# to embed credentials in code. | |
access_key = 'access_key' | |
secret_key = 'secret_key' | |
if access_key is None or secret_key is None: | |
print('No access key is available.') | |
sys.exit() | |
# Create a date for headers and the credential string | |
t = datetime.datetime.utcnow() | |
amz_date = t.strftime('%Y%m%dT%H%M%SZ') | |
date_stamp = t.strftime('%Y%m%d') # Date w/o time, used in credential scope | |
# ************* TASK 1: CREATE A CANONICAL REQUEST ************* | |
# http://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html | |
# Step 1 is to define the verb (GET, POST, etc.)--already done. | |
# Step 2: Create canonical URI--the part of the URI from domain to query | |
# string (use '/' if no path) | |
canonical_uri = '/' | |
## Step 3: Create the canonical query string. In this example, request | |
# parameters are passed in the body of the request and the query string | |
# is blank. | |
canonical_querystring = '' | |
# Step 4: Create the canonical headers. Header names must be trimmed | |
# and lowercase, and sorted in code point order from low to high. | |
# Note that there is a trailing \n. | |
canonical_headers = 'content-type:' + content_type + '\n' + 'host:' + host + '\n' + 'x-amz-date:' + amz_date + '\n' + 'x-amz-target:' + amz_target + '\n' | |
# Step 5: Create the list of signed headers. This lists the headers | |
# in the canonical_headers list, delimited with ";" and in alpha order. | |
# Note: The request can include any headers; canonical_headers and | |
# signed_headers include those that you want to be included in the | |
# hash of the request. "Host" and "x-amz-date" are always required. | |
# For DynamoDB, content-type and x-amz-target are also required. | |
signed_headers = 'content-type;host;x-amz-date;x-amz-target' | |
# Step 6: Create payload hash. In this example, the payload (body of | |
# the request) contains the request parameters. | |
payload_hash = hashlib.sha256(request_parameters.encode('utf-8')).hexdigest() | |
# Step 7: Combine elements to create canonical request | |
canonical_request = method + '\n' + canonical_uri + '\n' + canonical_querystring + '\n' + canonical_headers + '\n' + signed_headers + '\n' + payload_hash | |
# ************* TASK 2: CREATE THE STRING TO SIGN************* | |
# Match the algorithm to the hashing algorithm you use, either SHA-1 or | |
# SHA-256 (recommended) | |
algorithm = 'AWS4-HMAC-SHA256' | |
credential_scope = date_stamp + '/' + region + '/' + service + '/' + 'aws4_request' | |
string_to_sign = algorithm + '\n' + amz_date + '\n' + credential_scope + '\n' + hashlib.sha256( | |
canonical_request.encode('utf-8')).hexdigest() | |
# ************* TASK 3: CALCULATE THE SIGNATURE ************* | |
# Create the signing key using the function defined above. | |
signing_key = getSignatureKey(secret_key, date_stamp, region, service) | |
# Sign the string_to_sign using the signing_key | |
signature = hmac.new(signing_key, (string_to_sign).encode('utf-8'), hashlib.sha256).hexdigest() | |
# ************* TASK 4: ADD SIGNING INFORMATION TO THE REQUEST ************* | |
# Put the signature information in a header named Authorization. | |
authorization_header = algorithm + ' ' + 'Credential=' + access_key + '/' + credential_scope + ', ' + 'SignedHeaders=' + signed_headers + ', ' + 'Signature=' + signature | |
# For DynamoDB, the request can include any headers, but MUST include "host", "x-amz-date", | |
# "x-amz-target", "content-type", and "Authorization". Except for the authorization | |
# header, the headers must be included in the canonical_headers and signed_headers values, as | |
# noted earlier. Order here is not significant. | |
# # Python note: The 'host' header is added automatically by the Python 'requests' library. | |
headers = {'Content-Type': content_type, | |
'X-Amz-Date': amz_date, | |
'X-Amz-Target': amz_target, | |
'Authorization': authorization_header} | |
# ************* SEND THE REQUEST ************* | |
print('\nBEGIN REQUEST++++++++++++++++++++++++++++++++++++') | |
print('Request URL = ' + endpoint) | |
r = requests.post(endpoint, data=request_parameters, headers=headers) | |
print('\nRESPONSE++++++++++++++++++++++++++++++++++++') | |
print('Response code: %d\n' % r.status_code) | |
print(r.text) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment