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# 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
#
# <a href="http://aws.amazon.com/apache2.0/" target="_blank">http://aws.amazon.com/apache2.0/</a>
#
# 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.
#
# ABOUT THIS PYTHON SAMPLE: This sample is part of the AWS General Reference
# Signing AWS API Requests top available at
# <a href="https://docs.aws.amazon.com/general/latest/gr/sigv4-signed-request-examples.html" target="_blank">https://docs.aws.amazon.com/general/...-examples.html</a>
#
# AWS Version 4 signing example
# IAM API (CreateUser)
# See: <a href="http://docs.aws.amazon.com/general/latest/gr/sigv4_signing.html" target="_blank">http://docs.aws.amazon.com/general/l...4_signing.html</a>
# This version makes a GET request and passes request parameters
# and authorization information in the query string
import sys, os, base64, datetime, hashlib, hmac, urllib
import requests # pip install requests
# ************* REQUEST VALUES *************
method = 'GET'
service = 's3'
host = 's3.amazonaws.com'
region = 'us-east-1'
endpoint = 'https://s3.amazonaws.com'
# Key derivation functions. See:
# <a href="http://docs.aws.amazon.com/general/latest/gr/signature-v4-examples.html#signature-v4-examples-python" target="_blank">http://docs.aws.amazon.com/general/l...xamples-python</a>
def sign(key, msg):
return hmac.new(key, msg.encode('utf-8'), hashlib.sha256).digest()
def getSignatureKey(key, dateStamp, regionName, serviceName):
kDate = sign(('AWS4' + key).encode('utf-8'), dateStamp)
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') # Format date as YYYYMMDD'T'HHMMSS'Z'
datestamp = t.strftime('%Y%m%d') # Date w/o time, used in credential scope
# ************* TASK 1: CREATE A CANONICAL REQUEST *************
# <a href="http://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html" target="_blank">http://docs.aws.amazon.com/general/l...l-request.html</a>
# Because almost all information is being passed in the query string,
# the order of these steps is slightly different than examples that
# use an authorization header.
# Step 1: 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 headers and signed headers. Header names
# must be trimmed and lowercase, and sorted in code point order from
# low to high. Note trailing \n in canonical_headers.
# signed_headers is the list of headers that are being included
# as part of the signing process. For requests that use query strings,
# only "host" is included in the signed headers.
canonical_headers = 'host:' + host + '\n'
signed_headers = 'host'
# Match the algorithm to the hashing algorithm you use, either SHA-1 or
# SHA-256 (recommended)
algorithm = 'AWS4-HMAC-SHA256'
credential_scope = datestamp + '/' + region + '/' + service + '/' + 'aws4_request'
# Step 4: Create the canonical query string. In this example, request
# parameters are in the query string. Query string values must
# be URL-encoded (space=%20). The parameters must be sorted by name.
# use urllib.parse.quote_plus() if using Python 3
canonical_querystring = 'Action=CreateUser&UserName=NewUser&Version=2010-05-08'
canonical_querystring += '&X-Amz-Algorithm=AWS4-HMAC-SHA256'
canonical_querystring += '&X-Amz-Credential=' + urllib.parse.quote_plus(access_key + '/' + credential_scope)
canonical_querystring += '&X-Amz-Date=' + amz_date
canonical_querystring += '&X-Amz-Expires=30'
canonical_querystring += '&X-Amz-SignedHeaders=' + signed_headers
# Step 5: Create payload hash. For GET requests, the payload is an
# empty string ("").
payload_hash = hashlib.sha256(('').encode('utf-8')).hexdigest()
# Step 6: 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*************
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
signing_key = getSignatureKey(secret_key, datestamp, 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 *************
# The auth information can be either in a query string
# value or in a header named Authorization. This code shows how to put
# everything into a query string.
canonical_querystring += '&X-Amz-Signature=' + signature
# ************* SEND THE REQUEST *************
# The 'host' header is added automatically by the Python 'request' lib. But it
# must exist as a header in the request.
request_url = endpoint + "?" + canonical_querystring
print('\nBEGIN REQUEST++++++++++++++++++++++++++++++++++++')
print('Request URL = ' + request_url)
r = requests.get(request_url)
print('\nRESPONSE++++++++++++++++++++++++++++++++++++')
print('Response code: %d\n' % r.status_code)
print(r.text) |
