How to retrieve data from Cosmosdb using REST API

Question

I'm currently working on retrieving data from Cosmos DB using the REST API, but I've encountered an issue with the authorization header. When I attempt the operation, I'm met with the following error message:

{"code":"Unauthorized","message":"The input authorization token can't serve the request. The wrong key is being used or the expected payload is not built as per the protocol.}

I suspect the issue lies either with the way I'm generating the authorization token or perhaps with the structure of the payload I'm sending. I've double-checked the key I'm using, but I can't seem to pinpoint where the discrepancy lies.

Any insights or suggestions on how to resolve this authorization issue would be immensely appreciated.

Answer 1

Here the code that I am using:

def generate_master_key_authorization_signature(verb, resource_type, resource_link, date, key):
    key_type = "master"
    token_version = "1.0"
    payload = f"{verb.lower()}\n{resource_type.lower()}\n{resource_link}\n{date.lower()}\n\n"

    decoded_key = base64.b64decode(key)
    hmac_sha256 = hmac.new(decoded_key, payload.encode('utf-8'), hashlib.sha256)
    hash_payload = hmac_sha256.digest()
    signature = base64.encodebytes(hash_payload).decode('utf-8')
    auth_set = urllib.parse.quote(f"type={key_type}&ver={token_version}&sig={signature}")

    return auth_set

def get_cosmosdb_data():
    verb = 'GET'
    resource_type = 'docs'
    resource_link = f'dbs/{DATABASE_ID}/colls/{CONTAINER_ID}/docs'
    date = datetime.datetime.utcnow().strftime('%a, %d %b %Y %H:%M:%S GMT')
    print(date)
    auth_header = generate_master_key_authorization_signature(verb, resource_type, resource_link, date, COSMOSDB_PRIMARY_KEY)

    headers = {
        'Authorization': auth_header,
        'x-ms-version': '2018-12-31',
        'x-ms-date': date,
        'Content-Type': 'application/query+json',
        'x-ms-documentdb-isquery': 'True'
    }

    query = {"query": "SELECT * FROM c"}
    cosmosdb_uri = f"{COSMOSDB_URI}{resource_link}"
    print(cosmosdb_uri)

    response = requests.get(cosmosdb_uri, headers=headers, json=query)
    if response.status_code == 200:
        return response.json()
    else:
        raise Exception(f"Error retrieving data from Cosmos DB: {response.text}")

if __name__ == '__main__':
    data = get_cosmosdb_data()
    print(data)