chore: Update rego to be partial execution friendly

Emyrk · Emyrk · commit b3536bc315c9 · 2022-08-09T22:46:41.000-05:00
diff --git a/coderd/rbac/policy.rego b/coderd/rbac/policy.rego
@@ -1,11 +1,10 @@
 package authz
-import future.keywords.in
-import future.keywords.every
+import future.keywords
+# Helpful cli commands to debug.
+# opa eval --format=pretty 'data.authz.allow = true' -d policy.rego  -i input.json
+# opa eval --partial --format=pretty 'data.authz.allow = true' -d policy.rego --unknowns input.object.owner --unknowns input.object.org_owner -i input.json
+
 
-# A great playground: https://play.openpolicyagent.org/
-# TODO: Add debug instructions to do in the cli. Running really short on time, the
-#   playground is sufficient for now imo. In the future we can provide a tidy bash
-#   script for running this against predefined input.
 
 # bool_flip lets you assign a value to an inverted bool.
 # You cannot do 'x := !false', but you can do 'x := bool_flip(false)'
@@ -19,121 +18,95 @@ bool_flip(b) = flipped {
     flipped = true
 }
 
-# perms_grant returns a set of boolean values {true, false}.
-# True means a positive permission in the set, false is a negative permission.
-# It will only return `bool_flip(perm.negate)` for permissions that affect a given
-# resource_type, and action.
-# The empty set is returned if no relevant permissions are found.
-perms_grant(permissions) = grants {
-    # If there are no permissions, this value is the empty set {}.
-    grants := { x |
-        # All permissions ...
-        perm := permissions[_]
-        # Such that the permission action, and type matches
-        perm.action in [input.action, "*"]
-        perm.resource_type in [input.object.type, "*"]
-        x := bool_flip(perm.negate)
-    }
+number(set) = c {
+	count(set) == 0
+    c := 0
 }
 
-# Site & User are both very simple. We default both to the empty set '{}'. If no permissions are present, then the
-# result is the default value.
-default site = {}
-site = grant {
-    # Boolean set for all site wide permissions.
-    grant = { v | # Use set comprehension to remove duplicate values
-        # For each role, grab the site permission.
-        # Find the grants on this permission list.
-        v = perms_grant(input.subject.roles[_].site)[_]
-    }
+number(set) = c {
+	false in set
+    c := -1
 }
 
-default user = {}
-user = grant {
-    # Only apply user permissions if the user owns the resource
-    input.object.owner != ""
-    input.object.owner == input.subject.id
-    grant = { v |
-        # For each role, grab the user permissions.
-        # Find the grants on this permission list.
-        v = perms_grant(input.subject.roles[_].user)[_]
-    }
+number(set) = c {
+	not false in set
+	set[_]
+    c := 1
 }
 
-# Organizations are more complex. If the user has no roles that specifically indicate the org_id of the object,
-# then we want to block the action. This is because that means the user is not a member of the org.
-# A non-member cannot access any org resources.
 
-# org_member returns the set of permissions associated with a user if the user is a member of the
-# organization
-org_member = grant {
-    input.object.org_owner != ""
-    grant = { v |
-        v = perms_grant(input.subject.roles[_].org[input.object.org_owner])[_]
+default site = 0
+site := num {
+	# relevent are all the permissions that affect the given unknown object
+	allow := { x |
+    	perm := input.subject.roles[_].site[_]
+        perm.action in [input.action, "*"]
+		perm.resource_type in [input.object.type, "*"]
+        x := bool_flip(perm.negate)
     }
+    num := number(allow)
 }
 
-# If a user is not part of an organization, 'org_non_member' is set to true
-org_non_member {
-    input.object.org_owner != ""
-    # Identify if the user is in the org
-    roles := input.subject.roles
-    every role in roles {
-        not role.org[input.object.org_owner]
-    }
+org_members := { orgID |
+	input.subject.roles[_].org[orgID]
 }
 
-# org is two rules that equate to the following
-#	if org_non_member { return {false} }
-#	else { org_member }
-#
-# It is important both rules cannot be true, as the `org` rules cannot produce multiple outputs.
-default org = {}
-org = set {
-    # We have to do !org_non_member because rego rules must evaluate to 'true'
-    # to have a value set.
-    # So we do "not not-org-member" which means "subject is in org"
-    not org_non_member
-    set = org_member
+default org = 0
+org := num {
+	orgPerms := { id: num |
+		id := org_members[_]
+		set := { x |
+			perm := input.subject.roles[_].org[id][_]
+			perm.action in [input.action, "*"]
+			perm.resource_type in [input.object.type, "*"]
+			x := bool_flip(perm.negate)
+		}
+		num := number(set)
+	}
+
+	num := orgPerms[input.object.org_owner]
 }
 
-org = set {
-    org_non_member
-    set = {false}
+# 'org_mem' is set to true if the user is an org member
+# or if the object has no org.
+org_mem := true {
+	input.object.org_owner != ""
+	input.object.org_owner in org_members
 }
 
-# The allow block is quite simple. Any set with `false` cascades down in levels.
-# Authorization looks for any `allow` statement that is true. Multiple can be true!
-# Note that the absence of `allow` means "unauthorized".
-# An explicit `"allow": true` is required.
-
-# site allow
-allow {
-    # No site wide deny
-    not false in site
-    # And all permissions are positive
-    site[_]
+org_mem := true {
+	input.object.org_owner == ""
 }
 
-# OR
+default user = 0
+user := num {
+    input.subject.id = input.object.owner
+	# relevent are all the permissions that affect the given unknown object
+	allow := { x |
+    	perm := input.subject.roles[_].user[_]
+        perm.action in [input.action, "*"]
+		perm.resource_type in [input.object.type, "*"]
+        x := bool_flip(perm.negate)
+    }
+    num := number(allow)
+}
 
-# org allow
+default allow = false
+# Site
 allow {
-    # No site or org deny
-    not false in site
-    not false in org
-    # And all permissions are positive
-    org[_]
+	site = 1
 }
 
-# OR
+# Org
+allow {
+	not site = -1
+	org = 1
+}
 
-# user allow
+# User
 allow {
-    # No site, org, or user deny
-    not false in site
-    not false in org
-    not false in user
-    # And all permissions are positive
-    user[_]
+	not site = -1
+	not org = -1
+	org_mem
+	user = 1
 }
