open-consul/acl/errors.go
Mark Anderson fa95afdcf6 Refactor to make ACL errors more structured. (#12308)
* First phase of refactoring PermissionDeniedError

Add extended type PermissionDeniedByACLError that captures information
about the accessor, particular permission type and the object and name
of the thing being checked.

It may be worth folding the test and error return into a single helper
function, that can happen at a later date.

Signed-off-by: Mark Anderson <manderson@hashicorp.com>
2022-02-11 12:53:23 -08:00

129 lines
4.1 KiB
Go

package acl
import (
"errors"
"fmt"
"strings"
)
// These error constants define the standard ACL error types. The values
// must not be changed since the error values are sent via RPC calls
// from older clients and may not have the correct type.
const (
errNotFound = "ACL not found"
errRootDenied = "Cannot resolve root ACL"
errDisabled = "ACL support disabled"
errPermissionDenied = "Permission denied"
errInvalidParent = "Invalid Parent"
)
var (
// ErrNotFound indicates there is no matching ACL.
ErrNotFound = errors.New(errNotFound)
// ErrRootDenied is returned when attempting to resolve a root ACL.
ErrRootDenied = errors.New(errRootDenied)
// ErrDisabled is returned when ACL changes are not permitted since
// they are disabled.
ErrDisabled = errors.New(errDisabled)
// ErrPermissionDenied is returned when an ACL based rejection
// happens.
ErrPermissionDenied = PermissionDeniedError{}
// ErrInvalidParent is returned when a remotely resolve ACL
// token claims to have a non-root parent
ErrInvalidParent = errors.New(errInvalidParent)
)
// IsErrNotFound checks if the given error message is comparable to
// ErrNotFound.
func IsErrNotFound(err error) bool {
return err != nil && strings.Contains(err.Error(), errNotFound)
}
// IsErrRootDenied checks if the given error message is comparable to
// ErrRootDenied.
func IsErrRootDenied(err error) bool {
return err != nil && strings.Contains(err.Error(), errRootDenied)
}
// IsErrDisabled checks if the given error message is comparable to
// ErrDisabled.
func IsErrDisabled(err error) bool {
return err != nil && strings.Contains(err.Error(), errDisabled)
}
// IsErrPermissionDenied checks if the given error message is comparable
// to ErrPermissionDenied.
func IsErrPermissionDenied(err error) bool {
return err != nil && strings.Contains(err.Error(), errPermissionDenied)
}
// Arguably this should be some sort of union type.
// The usage of Cause and the rest of the fields is entirely disjoint.
//
type PermissionDeniedError struct {
Cause string
// Accessor contains information on the accessor used e.g. "token <GUID>"
Accessor string
// Resource (e.g. Service)
Resource Resource
// Access leve (e.g. Read)
AccessLevel AccessLevel
// e.g. "sidecar-proxy-1"
ResourceID ResourceDescriptor
}
// Initially we may not have attribution information; that will become more complete as we work this change through
// There are generally three classes of errors
// 1) Named entities without a context
// 2) Unnamed entities with a context
// 3) Completely context free checks (global permissions)
// 4) Errors that only have a cause (for example bad token)
func (e PermissionDeniedError) Error() string {
var message strings.Builder
message.WriteString(errPermissionDenied)
// Type 4)
if e.Cause != "" {
fmt.Fprintf(&message, ": %s", e.Cause)
return message.String()
}
// Should only be empty when default struct is used.
if e.Resource == "" {
return message.String()
}
if e.Accessor == "" {
message.WriteString(": provided accessor")
} else {
fmt.Fprintf(&message, ": accessor '%s'", e.Accessor)
}
fmt.Fprintf(&message, " lacks permission '%s:%s'", e.Resource, e.AccessLevel.String())
if e.ResourceID.Name != "" {
fmt.Fprintf(&message, " %s", e.ResourceID.ToString())
}
return message.String()
}
func PermissionDenied(msg string, args ...interface{}) PermissionDeniedError {
cause := fmt.Sprintf(msg, args...)
return PermissionDeniedError{Cause: cause}
}
// TODO Extract information from Authorizer
func PermissionDeniedByACL(_ Authorizer, context *AuthorizerContext, resource Resource, accessLevel AccessLevel, resourceID string) PermissionDeniedError {
desc := NewResourceDescriptor(resourceID, context)
return PermissionDeniedError{Accessor: "", Resource: resource, AccessLevel: accessLevel, ResourceID: desc}
}
func PermissionDeniedByACLUnnamed(_ Authorizer, context *AuthorizerContext, resource Resource, accessLevel AccessLevel) PermissionDeniedError {
desc := NewResourceDescriptor("", context)
return PermissionDeniedError{Accessor: "", Resource: resource, AccessLevel: accessLevel, ResourceID: desc}
}