update README, add CGI

Makefile

@@ -1,9 +1,14 @@
 PYTHON=python3
 
+ALLFILES=templates/S2_perm_sw.html templates/S4_server.py venv static/i-ico.png static/i-banner.png
+
 .PHONY: run
-run: templates/S2_perm_sw.html templates/S4_server.py venv static/i-ico.png static/i-banner.png
+run: $(ALLFILES)
 	($(VENVACT) && python templates/S4_server.py $(PORT) )
 
+.PHONY: files
+files: $(ALLFILES)
+
 VENVACT=. ./venv/bin/activate
 
 venv:

README.md

@@ -1,29 +1,123 @@
 Web Push Notifications (WPN)
 ===========================
 
-This is designed to be a super simple and small tool to push
-notifications to your end points.
+This is designed to be a super simple (understandable) and small tool
+to push notifications to web browsers (e.g. your cell phone).
+
+This code is partly copied from:
+https://gist.github.com/code-boxx/bc6aed37345ad1783cfb7d230f438120
+
+But put into a repo w/ better install instructions, and turned into a
+usable bit of code.
+
+The web browser Push API is fully encrypted and authenticated.  This
+means that only your server and the client will be able to see the
+contents of the message.
+
+There is also a limit of 4k for the entire message that is composed
+and sent to the server.  This means that the usable space for your
+own contents is around 3k, which is more than enough.
+
+
+Installation and Setup
+----------------------
+
+There are two ways to install it, one is to use it via the Flask web
+server, or via a CGI.
+
+### Flask web server
 
-Installation/running:
 ```
-git clonse <url>
+git clone https://www.funkthat.com/gitea/jmg/wpn
 cd wpn
 make run EMAIL=myemail@example.com PORT=<someport>
 ```
 
-This code is partly copied from:
-https://gist.github.com/code-boxx/bc6aed37345ad1783cfb7d230f438120
+Then you go to `http://127.0.0.1:<someport>/`, click the `Request
+Notifications` button.  The sub info will be printed to the console,
+and a second later, a notification should appear, and it'll be repeated
+every 10 seconds.  To change this behavior, look at the `donotify`
+fucntion in `src/S4_server.py`.
 
-But put into a repo w/ better install instructions, and turned into a
-usable bit of code.
 
+### CGI
+
+First build the files needed:
+```
+git clone https://www.funkthat.com/gitea/jmg/wpn
+cd wpn
+make files EMAIL=myemail@example.com
+```
+
+Then copy the files in the directory `static`, the files
+`template/S2_perm_sw.html` and `push.py` to a directory on your
+webserver.  In that directory, set push.py executable
+(`chmod 755 push.py`), and create a symlink to it from `push`:
+`ln -s push.py push`.
+
+Configure your web server such that the `push` is a CGI, and that
+`S2_perm_sw.html` is the index file.  This is how to do it via Apache:
+```
+<Directory "/location/on/webserver">
+  Options +ExecCGI
+  Order allow,deny
+  Allow from all
+  DirectoryIndex S2_perm_sw.html
+  <FilesMatch "push$">
+      SetHandler cgi-script
+  </FilesMatch>
+</Directory>
+```
+
+The `push.py` file is used to get the push notification subscription
+information from the browser and put it in `/tmp/subinfo.txt`.
+
+Note: The `push.py` has a hand implemented version of form decoding
+because Python had deprecated the `cgi` module.
+
+Pushing Notifications
+---------------------
+
+Using the subscription information from the previous step, put it
+in a file for use as `<filewsubjson>` below.
+
+The `pywebpush` program that is installed by the `pywebpush` module
+is used to send notifications:
+```
+jq --arg email myemail@example.com -n '{ "sub": ("mailto:" + $email) }' > claim.txt
+jq --arg msg 'somemessage' --arg title notification -n '{ "title": $title, "body": $msg, "icon" : "static/i-ico.png", "image" : "static/i-banner.png" }' |
+ pywebpush --data /dev/stdin --info <filewsubjson> --key keys/private_key.pem --claims claim.txt
+```
+
+As Python's `[venv](https://docs.python.org/3/library/venv.html#module-venv)`
+is used, you can simply execute/link to the pywebpush program in `venv/bin/`
+and not have to source the environment each time you need to run the program.
+
+Compatibility
+-------------
+
+Currently Firefox for Android does not allow Push notifications.  The
+nightly version does allow it.
+
+
+### cryptography
+
+If you have troubles installing the `cryptography` dependency (due to
+rust or other compile issues), but can install `pycryptodome`, you can
+use the [pycryptowrap](https://www.funkthat.com/gitea/jmg/pycryptowrap)
+instead.  To use it:
+```
+python3 -m venv venv
+(. ./venv/bin/activate && pip install git+https://www.funkthat.com/gitea/jmg/pycryptowrap )
+(. ./venv/bin/activate && pip install flask ecdsa pywebpush )
+```
 
 Notes
-=====
+-----
 
 If put behind a reverse proxy, make sure the url contains a trailing
 slash.  If you want the path w/o the slash to work, add a redirect as
-well.
+well.  Though if you use the CGI version, this is likely unneeded.
 
 For Apache:
 ```
@@ -32,5 +126,11 @@ LoadModule proxy_http_module libexec/apache22/mod_proxy_http.so
 
 ProxyPass "/wpn/" "http://internalwpn.example.com/"
 ProxyPassReverse "/wpn/" "http://internalwpn.example.com/"
-Redirect permanent /spn https://www.example.com/wpn/
+Redirect permanent /wpn https://www.example.com/wpn/
 ```
+
+See the introduction section on message limits.
+
+Yes, I probably should have used a better template language than `sed`,
+but this is simple and works.  It also makes it easy to copy over to a
+static site more easily.

push.py

@@ -0,0 +1,146 @@
+#!/usr/local/bin/python3
+
+import email.mime.multipart
+import os
+import sys
+import traceback
+import unittest
+
+from email.message import Message
+from urllib.parse import parse_qs
+
+def _deb(*args):
+	if True:
+		print(*args, file=sys.stderr)
+	
+def getdata(ct, bstr):
+	_deb('ct:', repr(ct))
+	_deb('bstr:', repr(bstr))
+	m = Message()
+	m['content-type'] = ct
+	boundary = '--' + m.get_param('boundary')
+
+	# trim the end:
+	_deb('bstr:', repr(bstr))
+
+	# pretend we had the previous record
+	body = b'\r\n' + bstr.split(('\r\n' + boundary + '--\r\n').encode('ASCII'), 1)[0]
+
+	_deb('body:', repr(body))
+
+	parts = body.split(('\r\n' + boundary + '\r\n').encode('ASCII'))[1:]
+
+	msgs = [ x for x in map(email.message_from_bytes, parts) if x.get_param('name', header='content-disposition') == 'sub' ]
+
+	return msgs[0].get_payload()
+
+if __name__ == '__main__':
+	_deb('env:', repr(os.environ))
+	contentlen = int(os.environ.get('CONTENT_LENGTH', '0'))
+
+	body = sys.stdin.buffer.read(contentlen)
+
+	try:
+		sub = getdata(os.environ.get('CONTENT_TYPE'), body)
+
+		os.umask(0o66)
+		with open('/tmp/subinfo.txt', 'w') as fp:
+			print(sub, file=fp)
+
+		print('Content-Type: text/plain\r')
+		print('\r')
+		print('OK\r')
+	except:
+		_deb(traceback.format_exc())
+
+		print('status: 500 Server Error\r')
+		print('Content-Type: text/plain\r')
+		print('\r')
+		print('ERROR\r')
+
+class Test(unittest.TestCase):
+	_testdata = '''
+	0x0040:       504f 5354 202f 7075 7368 2048 5454  ..POST./push.HTT
+	0x0050:  502f 312e 310d 0a48 6f73 743a 2031 3932  P/1.1..Host:.192
+	0x0060:  2e31 3638 2e30 2e33 0d0a 5573 6572 2d41  .168.0.3..User-A
+	0x0070:  6765 6e74 3a20 4d6f 7a69 6c6c 612f 352e  gent:.Mozilla/5.
+	0x0080:  3020 284d 6163 696e 746f 7368 3b20 496e  0.(Macintosh;.In
+	0x0090:  7465 6c20 4d61 6320 4f53 2058 2031 302e  tel.Mac.OS.X.10.
+	0x00a0:  3135 3b20 7276 3a31 3039 2e30 2920 4765  15;.rv:109.0).Ge
+	0x00b0:  636b 6f2f 3230 3130 3031 3031 2046 6972  cko/20100101.Fir
+	0x00c0:  6566 6f78 2f31 3135 2e30 0d0a 4163 6365  efox/115.0..Acce
+	0x00d0:  7074 3a20 2a2f 2a0d 0a41 6363 6570 742d  pt:.*/*..Accept-
+	0x00e0:  4c61 6e67 7561 6765 3a20 656e 2d55 532c  Language:.en-US,
+	0x00f0:  656e 3b71 3d30 2e35 0d0a 4163 6365 7074  en;q=0.5..Accept
+	0x0100:  2d45 6e63 6f64 696e 673a 2067 7a69 702c  -Encoding:.gzip,
+	0x0110:  2064 6566 6c61 7465 2c20 6272 0d0a 5265  .deflate,.br..Re
+	0x0120:  6665 7265 723a 2068 7474 7073 3a2f 2f77  ferer:.https://w
+	0x0130:  7777 2e66 756e 6b74 6861 742e 636f 6d2f  ww.funkthat.com/
+	0x0140:  7765 6270 7573 682f 0d0a 436f 6e74 656e  webpush/..Conten
+	0x0150:  742d 5479 7065 3a20 6d75 6c74 6970 6172  t-Type:.multipar
+	0x0160:  742f 666f 726d 2d64 6174 613b 2062 6f75  t/form-data;.bou
+	0x0170:  6e64 6172 793d 2d2d 2d2d 2d2d 2d2d 2d2d  ndary=----------
+	0x0180:  2d2d 2d2d 2d2d 2d2d 2d2d 2d2d 2d2d 2d2d  ----------------
+	0x0190:  2d33 3435 3837 3235 3136 3133 3033 3132  -345872516130312
+	0x01a0:  3635 3935 3233 3135 3033 3739 3130 310d  659523150379101.
+	0x01b0:  0a4f 7269 6769 6e3a 2068 7474 7073 3a2f  .Origin:.https:/
+	0x01c0:  2f77 7777 2e66 756e 6b74 6861 742e 636f  /www.funkthat.co
+	0x01d0:  6d0d 0a44 4e54 3a20 310d 0a53 6563 2d46  m..DNT:.1..Sec-F
+	0x01e0:  6574 6368 2d44 6573 743a 2065 6d70 7479  etch-Dest:.empty
+	0x01f0:  0d0a 5365 632d 4665 7463 682d 4d6f 6465  ..Sec-Fetch-Mode
+	0x0200:  3a20 636f 7273 0d0a 5365 632d 4665 7463  :.cors..Sec-Fetc
+	0x0210:  682d 5369 7465 3a20 7361 6d65 2d6f 7269  h-Site:.same-ori
+	0x0220:  6769 6e0d 0a53 6563 2d47 5043 3a20 310d  gin..Sec-GPC:.1.
+	0x0230:  0a58 2d46 6f72 7761 7264 6564 2d46 6f72  .X-Forwarded-For
+	0x0240:  3a20 3139 322e 3136 382e 302e 330d 0a58  :.192.168.0.3..X
+	0x0250:  2d46 6f72 7761 7264 6564 2d48 6f73 743a  -Forwarded-Host:
+	0x0260:  2077 7777 2e66 756e 6b74 6861 742e 636f  .www.funkthat.co
+	0x0270:  6d0d 0a58 2d46 6f72 7761 7264 6564 2d53  m..X-Forwarded-S
+	0x0280:  6572 7665 723a 2077 7777 2e66 756e 6b74  erver:.www.funkt
+	0x0290:  6861 742e 636f 6d0d 0a43 6f6e 6e65 6374  hat.com..Connect
+	0x02a0:  696f 6e3a 204b 6565 702d 416c 6976 650d  ion:.Keep-Alive.
+	0x02b0:  0a43 6f6e 7465 6e74 2d4c 656e 6774 683a  .Content-Length:
+	0x02c0:  2035 3833 0d0a 0d0a 2d2d 2d2d 2d2d 2d2d  .583....--------
+	0x02d0:  2d2d 2d2d 2d2d 2d2d 2d2d 2d2d 2d2d 2d2d  ----------------
+	0x02e0:  2d2d 2d2d 2d33 3435 3837 3235 3136 3133  -----34587251613
+	0x02f0:  3033 3132 3635 3935 3233 3135 3033 3739  0312659523150379
+	0x0300:  3130 310d 0a43 6f6e 7465 6e74 2d44 6973  101..Content-Dis
+	0x0310:  706f 7369 7469 6f6e 3a20 666f 726d 2d64  position:.form-d
+	0x0320:  6174 613b 206e 616d 653d 2273 7562 220d  ata;.name="sub".
+	0x0330:  0a0d 0a7b 2265 6e64 706f 696e 7422 3a22  ...{"endpoint":"
+	0x0340:  6874 7470 733a 2f2f 7570 6461 7465 732e  https://updates.
+	0x0350:  7075 7368 2e73 6572 7669 6365 732e 6d6f  push.services.mo
+	0x0360:  7a69 6c6c 612e 636f 6d2f 7770 7573 682f  zilla.com/wpush/
+	0x04c0:  5a4e 565a 6441 535f 4954 3822 7d7d 0d0a  ZNVZdAS_IT8"}}..
+	0x04d0:  2d2d 2d2d 2d2d 2d2d 2d2d 2d2d 2d2d 2d2d  ----------------
+	0x04e0:  2d2d 2d2d 2d2d 2d2d 2d2d 2d2d 2d33 3435  -------------345
+	0x04f0:  3837 3235 3136 3133 3033 3132 3635 3935  8725161303126595
+	0x0500:  3233 3135 3033 3739 3130 312d 2d0d 0a    23150379101--..
+'''
+
+	@staticmethod
+	def _process_hexdump(data):
+		lines = (x.split(':', 1)[1].strip().split('  ', 1)[0] for x in data.split('\n') if x.strip())
+
+		return bytes.fromhex(''.join(lines))
+
+	def test_basic(self):
+		bstr = self._process_hexdump(self._testdata)
+
+		# drop post line
+		bstr = bstr.split(b'\r\n', 1)[1]
+
+		_deb(repr(bstr))
+		msg = email.message_from_bytes(bstr)
+		_deb('msg hdrs:', repr(msg.items()))
+
+		# get ct
+		ct = msg['content-type']
+		_deb('ct:', repr(ct))
+
+		# get body:
+		body = bstr.split(b'\r\n\r\n', 1)[1]
+
+		# do the actual test:
+		res = getdata(ct, body)
+		self.assertEqual(res, '{"endpoint":"https://updates.push.services.mozilla.com/wpush/ZNVZdAS_IT8"}}')