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coder/coderd/rbac/policy.rego
Steven Masley 813270d63a chore: bump github.com/open-policy-agent/opa from 0.70.0 to 1.0.0 (#16013)
Opting into rego v1. Rego v1 requires `if` for all rule statements.

This PR updates the dependencies and the rego policy itself.

Golang imports upgraded for opa/rego

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
2025-01-03 11:06:47 -06:00

326 lines
9.3 KiB
Rego

package authz
import rego.v1
# A great playground: https://play.openpolicyagent.org/
# Helpful cli commands to debug.
# opa eval --format=pretty 'data.authz.allow' -d policy.rego -i input.json
# opa eval --partial --format=pretty 'data.authz.allow' -d policy.rego --unknowns input.object.owner --unknowns input.object.org_owner --unknowns input.object.acl_user_list --unknowns input.object.acl_group_list -i input.json
#
# This policy is specifically constructed to compress to a set of queries if the
# object's 'owner' and 'org_owner' fields are unknown. There is no specific set
# of rules that will guarantee that this policy has this property. However, there
# are some tricks. A unit test will enforce this property, so any edits that pass
# the unit test will be ok.
#
# Tricks: (It's hard to really explain this, fiddling is required)
# 1. Do not use unknown fields in any comprehension or iteration.
# 2. Use the unknown fields as minimally as possible.
# 3. Avoid making code branches based on the value of the unknown field.
# Unknown values are like a "set" of possible values.
# (This is why rule 1 usually breaks things)
# For example:
# In the org section, we calculate the 'allow' number for all orgs, rather
# than just the input.object.org_owner. This is because if the org_owner
# changes, then we don't need to recompute any 'allow' sets. We already have
# the 'allow' for the changed value. So the answer is in a lookup table.
# The final statement 'num := allow[input.object.org_owner]' does not have
# different code branches based on the org_owner. 'num's value does, but
# that is the whole point of partial evaluation.
# bool_flip lets you assign a value to an inverted bool.
# You cannot do 'x := !false', but you can do 'x := bool_flip(false)'
bool_flip(b) := flipped if {
b
flipped = false
}
bool_flip(b) := flipped if {
not b
flipped = true
}
# number is a quick way to get a set of {true, false} and convert it to
# -1: {false, true} or {false}
# 0: {}
# 1: {true}
number(set) := c if {
count(set) == 0
c := 0
}
number(set) := c if {
false in set
c := -1
}
number(set) := c if {
not false in set
set[_]
c := 1
}
# site, org, and user rules are all similar. Each rule should return a number
# from [-1, 1]. The number corresponds to "negative", "abstain", and "positive"
# for the given level. See the 'allow' rules for how these numbers are used.
default site := 0
site := site_allow(input.subject.roles)
default scope_site := 0
scope_site := site_allow([input.subject.scope])
site_allow(roles) := num if {
# allow is a set of boolean values without duplicates.
allow := {x |
# Iterate over all site permissions in all roles
perm := roles[_].site[_]
perm.action in [input.action, "*"]
perm.resource_type in [input.object.type, "*"]
# x is either 'true' or 'false' if a matching permission exists.
x := bool_flip(perm.negate)
}
num := number(allow)
}
# org_members is the list of organizations the actor is apart of.
org_members := {orgID |
input.subject.roles[_].org[orgID]
}
# org is the same as 'site' except we need to iterate over each organization
# that the actor is a member of.
default org := 0
org := org_allow(input.subject.roles)
default scope_org := 0
scope_org := org_allow([input.scope])
# org_allow_set is a helper function that iterates over all orgs that the actor
# is a member of. For each organization it sets the numerical allow value
# for the given object + action if the object is in the organization.
# The resulting value is a map that looks something like:
# {"10d03e62-7703-4df5-a358-4f76577d4e2f": 1, "5750d635-82e0-4681-bd44-815b18669d65": 1}
# The caller can use this output[<object.org_owner>] to get the final allow value.
#
# The reason we calculate this for all orgs, and not just the input.object.org_owner
# is that sometimes the input.object.org_owner is unknown. In those cases
# we have a list of org_ids that can we use in a SQL 'WHERE' clause.
org_allow_set(roles) := allow_set if {
allow_set := {id: num |
id := org_members[_]
set := {x |
perm := roles[_].org[id][_]
perm.action in [input.action, "*"]
perm.resource_type in [input.object.type, "*"]
x := bool_flip(perm.negate)
}
num := number(set)
}
}
org_allow(roles) := num if {
# If the object has "any_org" set to true, then use the other
# org_allow block.
not input.object.any_org
allow := org_allow_set(roles)
# Return only the org value of the input's org.
# The reason why we do not do this up front, is that we need to make sure
# this policy compresses down to simple queries. One way to ensure this is
# to keep unknown values out of comprehensions.
# (https://www.openpolicyagent.org/docs/latest/policy-language/#comprehensions)
num := allow[input.object.org_owner]
}
# This block states if "object.any_org" is set to true, then disregard the
# organization id the object is associated with. Instead, we check if the user
# can do the action on any organization.
# This is useful for UI elements when we want to conclude, "Can the user create
# a new template in any organization?"
# It is easier than iterating over every organization the user is apart of.
org_allow(roles) := num if {
input.object.any_org # if this is false, this code block is not used
allow := org_allow_set(roles)
# allow is a map of {"<org_id>": <number>}. We only care about values
# that are 1, and ignore the rest.
num := number([
keep |
# for every value in the mapping
value := allow[_]
# only keep values > 0.
# 1 = allow, 0 = abstain, -1 = deny
# We only need 1 explicit allow to allow the action.
# deny's and abstains are intentionally ignored.
value > 0
# result set is a set of [true,false,...]
# which "number()" will convert to a number.
keep := true
])
}
# 'org_mem' is set to true if the user is an org member
# If 'any_org' is set to true, use the other block to determine org membership.
org_mem if {
not input.object.any_org
input.object.org_owner != ""
input.object.org_owner in org_members
}
org_mem if {
input.object.any_org
count(org_members) > 0
}
org_ok if {
org_mem
}
# If the object has no organization, then the user is also considered part of
# the non-existent org.
org_ok if {
input.object.org_owner == ""
not input.object.any_org
}
# User is the same as the site, except it only applies if the user owns the object and
# the user is apart of the org (if the object has an org).
default user := 0
user := user_allow(input.subject.roles)
default user_scope := 0
scope_user := user_allow([input.scope])
user_allow(roles) := num if {
input.object.owner != ""
input.subject.id = input.object.owner
allow := {x |
perm := roles[_].user[_]
perm.action in [input.action, "*"]
perm.resource_type in [input.object.type, "*"]
x := bool_flip(perm.negate)
}
num := number(allow)
}
# Scope allow_list is a list of resource IDs explicitly allowed by the scope.
# If the list is '*', then all resources are allowed.
scope_allow_list if {
"*" in input.subject.scope.allow_list
}
scope_allow_list if {
# If the wildcard is listed in the allow_list, we do not care about the
# object.id. This line is included to prevent partial compilations from
# ever needing to include the object.id.
not "*" in input.subject.scope.allow_list
input.object.id in input.subject.scope.allow_list
}
# The allow block is quite simple. Any set with `-1` 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.
#
# Scope is also applied. The default scope is "wildcard:wildcard" allowing
# all actions. If the scope is not "1", then the action is not authorized.
#
#
# Allow query:
# data.authz.role_allow = true data.authz.scope_allow = true
role_allow if {
site = 1
}
role_allow if {
not site = -1
org = 1
}
role_allow if {
not site = -1
not org = -1
# If we are not a member of an org, and the object has an org, then we are
# not authorized. This is an "implied -1" for not being in the org.
org_ok
user = 1
}
scope_allow if {
scope_allow_list
scope_site = 1
}
scope_allow if {
scope_allow_list
not scope_site = -1
scope_org = 1
}
scope_allow if {
scope_allow_list
not scope_site = -1
not scope_org = -1
# If we are not a member of an org, and the object has an org, then we are
# not authorized. This is an "implied -1" for not being in the org.
org_ok
scope_user = 1
}
# ACL for users
acl_allow if {
# Should you have to be a member of the org too?
perms := input.object.acl_user_list[input.subject.id]
# Either the input action or wildcard
[input.action, "*"][_] in perms
}
# ACL for groups
acl_allow if {
# If there is no organization owner, the object cannot be owned by an
# org_scoped team.
org_mem
group := input.subject.groups[_]
perms := input.object.acl_group_list[group]
# Either the input action or wildcard
[input.action, "*"][_] in perms
}
# ACL for 'all_users' special group
acl_allow if {
org_mem
perms := input.object.acl_group_list[input.object.org_owner]
[input.action, "*"][_] in perms
}
###############
# Final Allow
# The role or the ACL must allow the action. Scopes can be used to limit,
# so scope_allow must always be true.
allow if {
role_allow
scope_allow
}
# ACL list must also have the scope_allow to pass
allow if {
acl_allow
scope_allow
}