providers/oauth2: add device flow (#3334)

* start device flow

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* web: fix inconsistent app filtering

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* add tenant device code flow

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* add throttling to device code view

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* somewhat unrelated changes

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* add initial device code entry flow

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* add finish stage

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* it works

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* add support for verification_uri_complete

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* add some tests

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* add more tests

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* add docs

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

authentik/lib/generators.py

@@ -3,13 +3,20 @@ import string
 from random import SystemRandom
 
 
-def generate_id(length=40):
+def generate_code_fixed_length(length=9) -> str:
+    """Generate a numeric code"""
+    rand = SystemRandom()
+    num = rand.randrange(1, 10**length)
+    return str(num).zfill(length)
+
+
+def generate_id(length=40) -> str:
     """Generate a random client ID"""
     rand = SystemRandom()
     return "".join(rand.choice(string.ascii_letters + string.digits) for x in range(length))
 
 
-def generate_key(length=128):
+def generate_key(length=128) -> str:
     """Generate a suitable client secret"""
     rand = SystemRandom()
     return "".join(