frostfs-node/pkg/services/object/acl/eacl/validator.go
Leonard Lyubich 69a69cdbee [#67] object/eacl: Implement eACL validator
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-10-02 19:46:45 +03:00

172 lines
3.7 KiB
Go

package eacl
import (
"bytes"
"github.com/nspcc-dev/neofs-api-go/pkg/acl/eacl"
crypto "github.com/nspcc-dev/neofs-crypto"
"github.com/nspcc-dev/neofs-node/pkg/util/logger"
"go.uber.org/zap"
)
// Validator is a tool that calculates
// the action on a request according
// to the extended ACL rule table.
type Validator struct {
*cfg
}
// Option represents Validator option.
type Option func(*cfg)
type cfg struct {
logger *logger.Logger
storage Storage
}
func defaultCfg() *cfg {
return &cfg{
logger: zap.L(),
}
}
// NewValidator creates and initializes a new Validator using options.
func NewValidator(opts ...Option) *Validator {
cfg := defaultCfg()
for i := range opts {
opts[i](cfg)
}
return &Validator{
cfg: cfg,
}
}
// CalculateAction calculates action on the request according
// to its information represented in ValidationUnit.
//
// The action is calculated according to the application of
// eACL table of rules to the request.
//
// If the eACL table is not available at the time of the call,
// eacl.ActionUnknown is returned.
//
// If no matching table entry is found, ActionAllow is returned.
func (v *Validator) CalculateAction(unit *ValidationUnit) eacl.Action {
// get eACL table by container ID
table, err := v.storage.GetEACL(unit.cid)
if err != nil {
v.logger.Error("could not get eACL table",
zap.String("error", err.Error()),
)
return eacl.ActionUnknown
}
return tableAction(unit, table)
}
// calculates action on the request based on the eACL rules.
func tableAction(unit *ValidationUnit, table *eacl.Table) eacl.Action {
for _, record := range table.Records() {
// check type of operation
if record.Operation() != unit.op {
continue
}
// check target
if !targetMatches(unit, record) {
continue
}
// check headers
switch val := matchFilters(unit.hdrSrc, record.Filters()); {
case val < 0:
// headers of some type could not be composed => allow
return eacl.ActionAllow
case val == 0:
return record.Action()
}
}
return eacl.ActionAllow
}
// returns:
// - positive value if no matching header is found for at least one filter;
// - zero if at least one suitable header is found for all filters;
// - negative value if the headers of at least one filter cannot be obtained.
func matchFilters(hdrSrc TypedHeaderSource, filters []eacl.Filter) int {
matched := 0
for _, filter := range filters {
headers, ok := hdrSrc.HeadersOfType(filter.From())
if !ok {
return -1
}
// get headers of filtering type
for _, header := range headers {
// prevent NPE
if header == nil {
continue
}
// check header name
if header.GetKey() != filter.Name() {
continue
}
// get match function
matchFn, ok := mMatchFns[filter.Matcher()]
if !ok {
continue
}
// check match
if !matchFn(header, filter) {
continue
}
// increment match counter
matched++
break
}
}
return len(filters) - matched
}
// returns true if one of ExtendedACLTarget has
// suitable target OR suitable public key.
func targetMatches(unit *ValidationUnit, record eacl.Record) bool {
for _, target := range record.Targets() {
// check public key match
for _, key := range target.Keys() {
if bytes.Equal(crypto.MarshalPublicKey(&key), unit.key) {
return true
}
}
// check target group match
if unit.role == target.Role() {
return true
}
}
return false
}
// Maps match type to corresponding function.
var mMatchFns = map[eacl.Match]func(Header, eacl.Filter) bool{
eacl.MatchStringEqual: func(header Header, filter eacl.Filter) bool {
return header.GetValue() == filter.Value()
},
eacl.MatchStringNotEqual: func(header Header, filter eacl.Filter) bool {
return header.GetValue() != filter.Value()
},
}