package auth import ( "bytes" "context" "crypto/ecdsa" "fmt" "io/ioutil" "net/http" "regexp" "strings" "time" aws_credentials "github.com/aws/aws-sdk-go/aws/credentials" v4 "github.com/aws/aws-sdk-go/aws/signer/v4" "github.com/nspcc-dev/neofs-api-go/refs" "github.com/nspcc-dev/neofs-api-go/service" "github.com/nspcc-dev/neofs-authmate/accessbox/hcs" "github.com/nspcc-dev/neofs-authmate/credentials" "github.com/nspcc-dev/neofs-authmate/gates" manager "github.com/nspcc-dev/neofs-authmate/neofsmanager" "github.com/pkg/errors" "go.uber.org/zap" ) var authorizationFieldRegexp = regexp.MustCompile(`AWS4-HMAC-SHA256 Credential=(?P[^/]+)/(?P[^/]+)/(?P[^/]+)/(?P[^/]*)/(?P[^/]+)/aws4_request,\s*SignedHeaders=(?P.+),\s*Signature=(?P.+)`) const emptyStringSHA256 = `e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855` // Center is a central app's authentication/authorization management unit. type Center struct { log *zap.Logger submatcher *regexpSubmatcher neofsCredentials *credentials.Credentials manager *manager.Manager authKeys *hcs.X25519Keys } // NewCenter creates an instance of AuthCenter. func NewCenter(log *zap.Logger, neofsNodeAddress string) (*Center, error) { m, err := manager.NewManager(neofsNodeAddress) if err != nil { return nil, err } return &Center{ log: log, submatcher: ®expSubmatcher{re: authorizationFieldRegexp}, manager: m, }, nil } func (center *Center) SetNeoFSKeys(key *ecdsa.PrivateKey) error { creds, err := credentials.NewFromKey(key) if err != nil { return err } center.neofsCredentials = creds return nil } func (center *Center) GetNeoFSPrivateKey() *ecdsa.PrivateKey { return center.neofsCredentials.Key() } func (center *Center) GetOwnerID() refs.OwnerID { return center.neofsCredentials.OwnerID() } func (center *Center) SetAuthKeys(key hcs.X25519PrivateKey) error { keys, err := hcs.NewKeys(key) if err != nil { return err } center.authKeys = keys return nil } func (center *Center) AuthenticationPassed(request *http.Request) (*service.BearerTokenMsg, error) { queryValues := request.URL.Query() if queryValues.Get("X-Amz-Algorithm") == "AWS4-HMAC-SHA256" { return nil, errors.New("pre-signed form of request is not supported") } authHeaderField := request.Header["Authorization"] if len(authHeaderField) != 1 { return nil, errors.New("unsupported request: wrong length of Authorization header field") } sms1 := center.submatcher.getSubmatches(authHeaderField[0]) if len(sms1) != 7 { return nil, errors.New("bad Authorization header field") } signedHeaderFieldsNames := strings.Split(sms1["signed_header_fields"], ";") if len(signedHeaderFieldsNames) == 0 { return nil, errors.New("wrong format of signed headers part") } signatureDateTime, err := time.Parse("20060102T150405Z", request.Header.Get("X-Amz-Date")) if err != nil { return nil, errors.Wrap(err, "failed to parse x-amz-date header field") } accessKeyID := fmt.Sprintf("%s/%s", sms1["access_key_id_cid"], sms1["access_key_id_oid"]) bearerToken, secretAccessKey, err := center.fetchBearerToken(accessKeyID) if err != nil { return nil, errors.Wrap(err, "failed to fetch bearer token") } otherRequest := request.Clone(context.TODO()) otherRequest.Header = map[string][]string{} for hfn, hfvs := range request.Header { for _, shfn := range signedHeaderFieldsNames { if strings.EqualFold(hfn, shfn) { otherRequest.Header[hfn] = hfvs } } } awsCreds := aws_credentials.NewStaticCredentials(accessKeyID, secretAccessKey, "") signer := v4.NewSigner(awsCreds) body, err := readAndKeepBody(request) if err != nil { return nil, errors.Wrap(err, "failed to read out request body") } _, err = signer.Sign(otherRequest, body, sms1["service"], sms1["region"], signatureDateTime) if err != nil { return nil, errors.Wrap(err, "failed to sign temporary HTTP request") } sms2 := center.submatcher.getSubmatches(otherRequest.Header.Get("Authorization")) if sms1["v4_signature"] != sms2["v4_signature"] { return nil, errors.Wrap(err, "failed to pass authentication procedure") } return bearerToken, nil } func (center *Center) fetchBearerToken(accessKeyID string) (*service.BearerTokenMsg, string, error) { akid := new(refs.Address) if err := akid.Parse(accessKeyID); err != nil { return nil, "", errors.Wrap(err, "failed to parse access key id as refs.Address") } config := &gates.ObtainingConfig{ BaseConfig: gates.BaseConfig{ OperationalCredentials: center.neofsCredentials, Manager: center.manager, }, GateKeys: center.authKeys, SecretAddress: akid, } res, err := gates.ObtainSecret(config) if err != nil { return nil, "", errors.Wrap(err, "failed to obtain secret") } return res.BearerToken, res.SecretAccessKey, nil } // TODO: Make this write into a smart buffer backed by a file on a fast drive. func readAndKeepBody(request *http.Request) (*bytes.Reader, error) { if request.Body == nil { var r bytes.Reader return &r, nil } payload, err := ioutil.ReadAll(request.Body) if err != nil { return nil, err } request.Body = ioutil.NopCloser(bytes.NewReader(payload)) return bytes.NewReader(payload), nil } func LoadGateAuthPrivateKey(path string) (hcs.X25519PrivateKey, error) { return ioutil.ReadFile(path) }