git.cworth.org Git - turbot/blob - turbot/slack.py

   1 import hashlib
   2 import hmac
   3 import os
   4 import boto3
   5
   6 if 'SLACK_SIGNING_SECRET' in os.environ:
   7     slack_signing_secret = os.environ['SLACK_SIGNING_SECRET']
   8 else:
   9     ssm = boto3.client('ssm')
  10     response = ssm.get_parameter(Name='SLACK_SIGNING_SECRET',
  11                                  WithDecryption=True)
  12     slack_signing_secret = response['Parameter']['Value']
  13     os.environ['SLACK_SIGNING_SECRET'] = slack_signing_secret
  14
  15 slack_signing_secret = bytes(os.environ['SLACK_SIGNING_SECRET'], 'utf-8')
  16
  17 def slack_is_valid_request(slack_signature, timestamp, body):
  18     """Returns True if the timestamp and body correspond to signature.
  19
  20     This implements the Slack signature verification using the slack
  21     signing secret (obtained via an SSM parameter in code above)."""
  22
  23     content = "v0:{}:{}".format(timestamp, body).encode('utf-8')
  24
  25     signature = 'v0=' + hmac.new(slack_signing_secret,
  26                                  content,
  27                                  hashlib.sha256).hexdigest()
  28
  29     if hmac.compare_digest(signature, slack_signature):
  30         return True
  31     else:
  32         print("Bad signature: {} != {}".format(signature, slack_signature))
  33         return False
  34
  35 def slack_channel_members(slack_client, channel_id):
  36     members = []
  37
  38     cursor = None
  39     while True:
  40         if cursor:
  41             response = slack_client.conversations_members(channel=channel_id,
  42                                                           cursor=cursor)
  43         else:
  44             response = slack_client.conversations_members(channel=channel_id)
  45
  46         if response['ok']:
  47             members += response['members']
  48         else:
  49             print("Error querying members of channel {}: {}"
  50                   .format(channel_id, response['error']))
  51             return members
  52
  53         cursor = None
  54         if 'next_cursor' in response['response_metadata']:
  55             cursor = response['response_metadata']['next_cursor']
  56
  57         if not cursor or cursor == '':
  58             break
  59
  60     return members
  61
  62 def slack_send_message(slack_client, channel_id, text, blocks=None):
  63     if blocks:
  64         slack_client.chat_postMessage(channel=channel_id,
  65                                       text=text, blocks=blocks)
  66     else:
  67         slack_client.chat_postMessage(channel=channel_id, text=text)