chore: Merge some rbac files, move some functions around (#6916)

* chore: Merge some rbac files, move some functions around

* Fix imports
This commit is contained in:
Steven Masley
2023-03-31 09:46:38 -05:00
committed by GitHub
parent 27e17ff2c3
commit ce51435507
8 changed files with 203 additions and 223 deletions

View File

@ -1,16 +0,0 @@
package rbac
// Action represents the allowed actions to be done on an object.
type Action string
const (
ActionCreate Action = "create"
ActionRead Action = "read"
ActionUpdate Action = "update"
ActionDelete Action = "delete"
)
// AllActions is a helper function to return all the possible actions types.
func AllActions() []Action {
return []Action{ActionCreate, ActionRead, ActionUpdate, ActionDelete}
}

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@ -6,6 +6,7 @@ import (
"sync" "sync"
"time" "time"
"github.com/open-policy-agent/opa/ast"
"github.com/open-policy-agent/opa/rego" "github.com/open-policy-agent/opa/rego"
"github.com/prometheus/client_golang/prometheus" "github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto" "github.com/prometheus/client_golang/prometheus/promauto"
@ -18,6 +19,21 @@ import (
"github.com/coder/coder/coderd/util/slice" "github.com/coder/coder/coderd/util/slice"
) )
// Action represents the allowed actions to be done on an object.
type Action string
const (
ActionCreate Action = "create"
ActionRead Action = "read"
ActionUpdate Action = "update"
ActionDelete Action = "delete"
)
// AllActions is a helper function to return all the possible actions types.
func AllActions() []Action {
return []Action{ActionCreate, ActionRead, ActionUpdate, ActionDelete}
}
// Subject is a struct that contains all the elements of a subject in an rbac // Subject is a struct that contains all the elements of a subject in an rbac
// authorize. // authorize.
type Subject struct { type Subject struct {
@ -329,3 +345,190 @@ func (a RegoAuthorizer) Prepare(ctx context.Context, subject Subject, action Act
a.prepareHist.Observe(time.Since(start).Seconds()) a.prepareHist.Observe(time.Since(start).Seconds())
return prepared, nil return prepared, nil
} }
// PartialAuthorizer is a prepared authorizer with the subject, action, and
// resource type fields already filled in. This speeds up authorization
// when authorizing the same type of object numerous times.
// See rbac.Filter for example usage.
type PartialAuthorizer struct {
// partialQueries is mainly used for unit testing to assert our rego policy
// can always be compressed into a set of queries.
partialQueries *rego.PartialQueries
// input is used purely for debugging and logging.
subjectInput Subject
subjectAction Action
subjectResourceType Object
// preparedQueries are the compiled set of queries after partial evaluation.
// Cache these prepared queries to avoid re-compiling the queries.
// If alwaysTrue is true, then ignore these.
preparedQueries []rego.PreparedEvalQuery
// alwaysTrue is if the subject can always perform the action on the
// resource type, regardless of the unknown fields.
alwaysTrue bool
}
var _ PreparedAuthorized = (*PartialAuthorizer)(nil)
// CompileToSQL converts the remaining rego queries into SQL WHERE clauses.
func (pa *PartialAuthorizer) CompileToSQL(ctx context.Context, cfg regosql.ConvertConfig) (string, error) {
_, span := tracing.StartSpan(ctx, trace.WithAttributes(
// Query count is a rough indicator of the complexity of the query
// that needs to be converted into SQL.
attribute.Int("query_count", len(pa.preparedQueries)),
attribute.Bool("always_true", pa.alwaysTrue),
))
defer span.End()
filter, err := Compile(cfg, pa)
if err != nil {
return "", xerrors.Errorf("compile: %w", err)
}
return filter.SQLString(), nil
}
func (pa *PartialAuthorizer) Authorize(ctx context.Context, object Object) error {
if pa.alwaysTrue {
return nil
}
// If we have no queries, then no queries can return 'true'.
// So the result is always 'false'.
if len(pa.preparedQueries) == 0 {
return ForbiddenWithInternal(xerrors.Errorf("policy disallows request"),
pa.subjectInput, pa.subjectAction, pa.subjectResourceType, nil)
}
parsed, err := ast.InterfaceToValue(map[string]interface{}{
"object": object,
})
if err != nil {
return xerrors.Errorf("parse object: %w", err)
}
// How to interpret the results of the partial queries.
// We have a list of queries that are along the lines of:
// `input.object.org_owner = ""; "me" = input.object.owner`
// `input.object.org_owner in {"feda2e52-8bf1-42ce-ad75-6c5595cb297a"} `
// All these queries are joined by an 'OR'. So we need to run through each
// query, and evaluate it.
//
// In each query, we have a list of the expressions, which should be
// all boolean expressions. In the above 1st example, there are 2.
// These expressions within a single query are `AND` together by rego.
EachQueryLoop:
for _, q := range pa.preparedQueries {
// We need to eval each query with the newly known fields.
results, err := q.Eval(ctx, rego.EvalParsedInput(parsed))
if err != nil {
continue EachQueryLoop
}
// If there are no results, then the query is false. This is because rego
// treats false queries as "undefined". So if any expression is false, the
// result is an empty list.
if len(results) == 0 {
continue EachQueryLoop
}
// If there is more than 1 result, that means there is more than 1 rule.
// This should not happen, because our query should always be an expression.
// If this every occurs, it is likely the original query was not an expression.
if len(results) > 1 {
continue EachQueryLoop
}
// Our queries should be simple, and should not yield any bindings.
// A binding is something like 'x := 1'. This binding as an expression is
// 'true', but in our case is unhelpful. We are not analyzing this ast to
// map bindings. So just error out. Similar to above, our queries should
// always be boolean expressions.
if len(results[0].Bindings) > 0 {
continue EachQueryLoop
}
// We have a valid set of boolean expressions! All expressions are 'AND'd
// together. This is automatic by rego, so we should not actually need to
// inspect this any further. But just in case, we will verify each expression
// did resolve to 'true'. This is purely defensive programming.
for _, exp := range results[0].Expressions {
if v, ok := exp.Value.(bool); !ok || !v {
continue EachQueryLoop
}
}
return nil
}
return ForbiddenWithInternal(xerrors.Errorf("policy disallows request"),
pa.subjectInput, pa.subjectAction, pa.subjectResourceType, nil)
}
func (a RegoAuthorizer) newPartialAuthorizer(ctx context.Context, subject Subject, action Action, objectType string) (*PartialAuthorizer, error) {
if subject.Roles == nil {
return nil, xerrors.Errorf("subject must have roles")
}
if subject.Scope == nil {
return nil, xerrors.Errorf("subject must have a scope")
}
input, err := regoPartialInputValue(subject, action, objectType)
if err != nil {
return nil, xerrors.Errorf("prepare input: %w", err)
}
partialQueries, err := a.partialQuery.Partial(ctx, rego.EvalParsedInput(input))
if err != nil {
return nil, xerrors.Errorf("prepare: %w", err)
}
pAuth := &PartialAuthorizer{
partialQueries: partialQueries,
preparedQueries: []rego.PreparedEvalQuery{},
subjectInput: subject,
subjectResourceType: Object{
Type: objectType,
ID: "prepared-object",
},
subjectAction: action,
}
// Prepare each query to optimize the runtime when we iterate over the objects.
preparedQueries := make([]rego.PreparedEvalQuery, 0, len(partialQueries.Queries))
for _, q := range partialQueries.Queries {
if q.String() == "" {
// No more work needed. An empty query is the same as
// 'WHERE true'
// This is likely an admin. We don't even need to use rego going
// forward.
pAuth.alwaysTrue = true
preparedQueries = []rego.PreparedEvalQuery{}
break
}
results, err := rego.New(
rego.ParsedQuery(q),
).PrepareForEval(ctx)
if err != nil {
return nil, xerrors.Errorf("prepare query %s: %w", q.String(), err)
}
preparedQueries = append(preparedQueries, results)
}
pAuth.preparedQueries = preparedQueries
return pAuth, nil
}
// rbacTraceAttributes are the attributes that are added to all spans created by
// the rbac package. These attributes should help to debug slow spans.
func rbacTraceAttributes(actor Subject, action Action, objectType string, extra ...attribute.KeyValue) trace.SpanStartOption {
return trace.WithAttributes(
append(extra,
attribute.StringSlice("subject_roles", actor.SafeRoleNames()),
attribute.Int("num_subject_roles", len(actor.SafeRoleNames())),
attribute.Int("num_groups", len(actor.Groups)),
attribute.String("scope", actor.SafeScopeName()),
attribute.String("action", string(action)),
attribute.String("object_type", objectType),
)...)
}

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@ -1,182 +0,0 @@
package rbac
import (
"context"
"github.com/open-policy-agent/opa/ast"
"github.com/open-policy-agent/opa/rego"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/trace"
"golang.org/x/xerrors"
"github.com/coder/coder/coderd/rbac/regosql"
"github.com/coder/coder/coderd/tracing"
)
type PartialAuthorizer struct {
// partialQueries is mainly used for unit testing to assert our rego policy
// can always be compressed into a set of queries.
partialQueries *rego.PartialQueries
// input is used purely for debugging and logging.
subjectInput Subject
subjectAction Action
subjectResourceType Object
// preparedQueries are the compiled set of queries after partial evaluation.
// Cache these prepared queries to avoid re-compiling the queries.
// If alwaysTrue is true, then ignore these.
preparedQueries []rego.PreparedEvalQuery
// alwaysTrue is if the subject can always perform the action on the
// resource type, regardless of the unknown fields.
alwaysTrue bool
}
var _ PreparedAuthorized = (*PartialAuthorizer)(nil)
func (pa *PartialAuthorizer) CompileToSQL(ctx context.Context, cfg regosql.ConvertConfig) (string, error) {
_, span := tracing.StartSpan(ctx, trace.WithAttributes(
// Query count is a rough indicator of the complexity of the query
// that needs to be converted into SQL.
attribute.Int("query_count", len(pa.preparedQueries)),
attribute.Bool("always_true", pa.alwaysTrue),
))
defer span.End()
filter, err := Compile(cfg, pa)
if err != nil {
return "", xerrors.Errorf("compile: %w", err)
}
return filter.SQLString(), nil
}
func (pa *PartialAuthorizer) Authorize(ctx context.Context, object Object) error {
if pa.alwaysTrue {
return nil
}
// If we have no queries, then no queries can return 'true'.
// So the result is always 'false'.
if len(pa.preparedQueries) == 0 {
return ForbiddenWithInternal(xerrors.Errorf("policy disallows request"),
pa.subjectInput, pa.subjectAction, pa.subjectResourceType, nil)
}
parsed, err := ast.InterfaceToValue(map[string]interface{}{
"object": object,
})
if err != nil {
return xerrors.Errorf("parse object: %w", err)
}
// How to interpret the results of the partial queries.
// We have a list of queries that are along the lines of:
// `input.object.org_owner = ""; "me" = input.object.owner`
// `input.object.org_owner in {"feda2e52-8bf1-42ce-ad75-6c5595cb297a"} `
// All these queries are joined by an 'OR'. So we need to run through each
// query, and evaluate it.
//
// In each query, we have a list of the expressions, which should be
// all boolean expressions. In the above 1st example, there are 2.
// These expressions within a single query are `AND` together by rego.
EachQueryLoop:
for _, q := range pa.preparedQueries {
// We need to eval each query with the newly known fields.
results, err := q.Eval(ctx, rego.EvalParsedInput(parsed))
if err != nil {
continue EachQueryLoop
}
// If there are no results, then the query is false. This is because rego
// treats false queries as "undefined". So if any expression is false, the
// result is an empty list.
if len(results) == 0 {
continue EachQueryLoop
}
// If there is more than 1 result, that means there is more than 1 rule.
// This should not happen, because our query should always be an expression.
// If this every occurs, it is likely the original query was not an expression.
if len(results) > 1 {
continue EachQueryLoop
}
// Our queries should be simple, and should not yield any bindings.
// A binding is something like 'x := 1'. This binding as an expression is
// 'true', but in our case is unhelpful. We are not analyzing this ast to
// map bindings. So just error out. Similar to above, our queries should
// always be boolean expressions.
if len(results[0].Bindings) > 0 {
continue EachQueryLoop
}
// We have a valid set of boolean expressions! All expressions are 'AND'd
// together. This is automatic by rego, so we should not actually need to
// inspect this any further. But just in case, we will verify each expression
// did resolve to 'true'. This is purely defensive programming.
for _, exp := range results[0].Expressions {
if v, ok := exp.Value.(bool); !ok || !v {
continue EachQueryLoop
}
}
return nil
}
return ForbiddenWithInternal(xerrors.Errorf("policy disallows request"),
pa.subjectInput, pa.subjectAction, pa.subjectResourceType, nil)
}
func (a RegoAuthorizer) newPartialAuthorizer(ctx context.Context, subject Subject, action Action, objectType string) (*PartialAuthorizer, error) {
if subject.Roles == nil {
return nil, xerrors.Errorf("subject must have roles")
}
if subject.Scope == nil {
return nil, xerrors.Errorf("subject must have a scope")
}
input, err := regoPartialInputValue(subject, action, objectType)
if err != nil {
return nil, xerrors.Errorf("prepare input: %w", err)
}
partialQueries, err := a.partialQuery.Partial(ctx, rego.EvalParsedInput(input))
if err != nil {
return nil, xerrors.Errorf("prepare: %w", err)
}
pAuth := &PartialAuthorizer{
partialQueries: partialQueries,
preparedQueries: []rego.PreparedEvalQuery{},
subjectInput: subject,
subjectResourceType: Object{
Type: objectType,
ID: "prepared-object",
},
subjectAction: action,
}
// Prepare each query to optimize the runtime when we iterate over the objects.
preparedQueries := make([]rego.PreparedEvalQuery, 0, len(partialQueries.Queries))
for _, q := range partialQueries.Queries {
if q.String() == "" {
// No more work needed. An empty query is the same as
// 'WHERE true'
// This is likely an admin. We don't even need to use rego going
// forward.
pAuth.alwaysTrue = true
preparedQueries = []rego.PreparedEvalQuery{}
break
}
results, err := rego.New(
rego.ParsedQuery(q),
).PrepareForEval(ctx)
if err != nil {
return nil, xerrors.Errorf("prepare query %s: %w", q.String(), err)
}
preparedQueries = append(preparedQueries, results)
}
pAuth.preparedQueries = preparedQueries
return pAuth, nil
}

View File

@ -1,7 +1,6 @@
package rbac package rbac
import ( import (
"context"
"strings" "strings"
"github.com/coder/coder/coderd/rbac/regosql" "github.com/coder/coder/coderd/rbac/regosql"
@ -55,10 +54,6 @@ func Compile(cfg regosql.ConvertConfig, pa *PartialAuthorizer) (AuthorizeFilter,
}, nil }, nil
} }
func (a *authorizedSQLFilter) Eval(object Object) bool {
return a.auth.Authorize(context.Background(), object) == nil
}
func (a *authorizedSQLFilter) SQLString() string { func (a *authorizedSQLFilter) SQLString() string {
return a.sqlString return a.sqlString
} }

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@ -1,20 +0,0 @@
package rbac
import (
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/trace"
)
// rbacTraceAttributes are the attributes that are added to all spans created by
// the rbac package. These attributes should help to debug slow spans.
func rbacTraceAttributes(actor Subject, action Action, objectType string, extra ...attribute.KeyValue) trace.SpanStartOption {
return trace.WithAttributes(
append(extra,
attribute.StringSlice("subject_roles", actor.SafeRoleNames()),
attribute.Int("num_subject_roles", len(actor.SafeRoleNames())),
attribute.Int("num_groups", len(actor.Groups)),
attribute.String("scope", actor.SafeScopeName()),
attribute.String("action", string(action)),
attribute.String("object_type", objectType),
)...)
}