PUT request to Azure storage with shared key authorization

Question

I am trying to make a put request to Azure storage, basically changing the storage properties. While I can able to make the GET request work by following the tutorial here https://docs.microsoft.com/en-us/rest/api/storageservices/authorize-with-shared-key#Subheading2 but I dont see a proper one to construct a PUT request in there.

So, while searching I got this but with the get, can't connect to azure file service REST api by python but this is again with a GET request. for the PUT request am always getting HTTP 403, I am not sure where it fails. here is the modified code from the link to depict what I am doing in my code.

import requests
import datetime
import hmac
import hashlib
import base64

storage_account_name = 'strtest'
storage_account_key = 'key'
api_version = '2016-05-31'
request_time = datetime.datetime.utcnow().strftime('%a, %d %b %Y %H:%M:%S GMT')

string_params = {
    'verb': 'PUT',
    'Content-Encoding': '',
    'Content-Language': '',
    'Content-Length': '',
    'Content-MD5': '',
    'Content-Type': 'application/xml',
    'Date': '',
    'If-Modified-Since': '',
    'If-Match': '',
    'If-None-Match': '',
    'If-Unmodified-Since': '',
    'Range': '',
    'CanonicalizedHeaders': 'x-ms-date:' + request_time + '\nx-ms-version:' + api_version + '\n',
    'CanonicalizedResource': '/' + storage_account_name + '/\ncomp:properties\nrestype:service'
}

string_to_sign = (string_params['verb'] + '\n'
                  + string_params['Content-Encoding'] + '\n'
                  + string_params['Content-Language'] + '\n'
                  + string_params['Content-Length'] + '\n'
                  + string_params['Content-MD5'] + '\n'
                  + string_params['Content-Type'] + '\n'
                  + string_params['Date'] + '\n'
                  + string_params['If-Modified-Since'] + '\n'
                  + string_params['If-Match'] + '\n'
                  + string_params['If-None-Match'] + '\n'
                  + string_params['If-Unmodified-Since'] + '\n'
                  + string_params['Range'] + '\n'
                  + string_params['CanonicalizedHeaders']
                  + string_params['CanonicalizedResource'])

signed_string = base64.b64encode(hmac.new(base64.b64decode(storage_account_key), msg=string_to_sign.encode('utf-8'), digestmod=hashlib.sha256).digest()).decode()

headers = {
    'x-ms-date' : request_time,
    'x-ms-version' : api_version,
    'Authorization' : ('SharedKey ' + storage_account_name + ':' + signed_string)
}

url = ('https://' + storage_account_name + '.blob.core.windows.net/?restype=service&comp=properties')

data = """<StorageServiceProperties></StorageServiceProperties>"""

r = requests.put(url, headers = headers, data = data)

print(r.content)

The content am trying to send is in XML format. While the code is working on GET request PUT is not.

Answer 1

Besides Content-Type, for a put request, you also need to fill Content-Length in string_params as corresponding header is probably set by sdk automatically.

Answer 2

Here is the working code.

import requests
import datetime
import hmac
import hashlib
import base64

storage_account_name = 'acc_name'
storage_account_key = 'ac_key'
api_version = '2018-03-28'
request_time = datetime.datetime.utcnow().strftime('%a, %d %b %Y %H:%M:%S GMT')
data = "<StorageServiceProperties></StorageServiceProperties>"
content_len = str(len(data))

string_params = {
    'verb': 'PUT',
    'Content-Encoding': '',
    'Content-Language': '',
    'Content-Length': content_len,
    'Content-MD5': '',
    'Content-Type': 'application/xml',
    'Date': '',
    'If-Modified-Since': '',
    'If-Match': '',
    'If-None-Match': '',
    'If-Unmodified-Since': '',
    'Range': '',
    'CanonicalizedHeaders': 'x-ms-date:' + request_time + '\nx-ms-version:' + api_version + '\n',
    'CanonicalizedResource': '/' + storage_account_name + '/\ncomp:properties\nrestype:service'
}

string_to_sign = (string_params['verb'] + '\n'
                  + string_params['Content-Encoding'] + '\n'
                  + string_params['Content-Language'] + '\n'
                  + string_params['Content-Length'] + '\n'
                  + string_params['Content-MD5'] + '\n'
                  + string_params['Content-Type'] + '\n'
                  + string_params['Date'] + '\n'
                  + string_params['If-Modified-Since'] + '\n'
                  + string_params['If-Match'] + '\n'
                  + string_params['If-None-Match'] + '\n'
                  + string_params['If-Unmodified-Since'] + '\n'
                  + string_params['Range'] + '\n'
                  + string_params['CanonicalizedHeaders']
                  + string_params['CanonicalizedResource'])

signed_string = base64.b64encode(hmac.new(base64.b64decode(storage_account_key), msg=string_to_sign.encode('utf-8'), digestmod=hashlib.sha256).digest()).decode()

headers = {
    'x-ms-date' : request_time,
    'x-ms-version' : api_version,
    'Content-Type': 'application/xml',
    'Content-Length': content_len,
    'Authorization' : ('SharedKey ' + storage_account_name + ':' + signed_string)
}

url = ('https://' + storage_account_name + '.blob.core.windows.net/?restype=service&comp=properties')

data = "<StorageServiceProperties></StorageServiceProperties>"

r = requests.put(url, headers = headers, data=data)

print(r.content)