frostfs-node/pkg/services/util/sign.go
Leonard Lyubich 8a2a096680 [] services/sign: Convert error to status return
In previous implementation `SignService` converted all `error` values to
`INTERNAL` server failure status. That was done for simplification only.
There is a need to transmit status errors as corresponding status
messages.

Make `SignService` to unwrap errors and convert them to status message
during writing to the response. Non-status errors are converted to
`INTERNAL` server failures. Status errors can also be wrapped in the
depths of the executable code, so `SignService` tries to unwrap them.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2022-03-15 13:03:23 +03:00

246 lines
5.6 KiB
Go

package util
import (
"context"
"crypto/ecdsa"
"errors"
"fmt"
"github.com/nspcc-dev/neofs-api-go/v2/session"
"github.com/nspcc-dev/neofs-api-go/v2/signature"
apistatus "github.com/nspcc-dev/neofs-sdk-go/client/status"
)
type RequestMessage interface {
GetMetaHeader() *session.RequestMetaHeader
}
// ResponseMessage is an interface of NeoFS response message.
type ResponseMessage interface {
GetMetaHeader() *session.ResponseMetaHeader
SetMetaHeader(*session.ResponseMetaHeader)
}
type UnaryHandler func(context.Context, interface{}) (ResponseMessage, error)
type SignService struct {
key *ecdsa.PrivateKey
}
type ResponseMessageWriter func(ResponseMessage) error
type ServerStreamHandler func(context.Context, interface{}) (ResponseMessageReader, error)
type ResponseMessageReader func() (ResponseMessage, error)
var ErrAbortStream = errors.New("abort message stream")
type ResponseConstructor func() ResponseMessage
type RequestMessageWriter func(interface{}) error
type ClientStreamCloser func() (ResponseMessage, error)
type RequestMessageStreamer struct {
key *ecdsa.PrivateKey
send RequestMessageWriter
close ClientStreamCloser
respCons ResponseConstructor
statusSupported bool
sendErr error
}
func NewUnarySignService(key *ecdsa.PrivateKey) *SignService {
return &SignService{
key: key,
}
}
func (s *RequestMessageStreamer) Send(req interface{}) error {
// req argument should be strengthen with type RequestMessage
s.statusSupported = isStatusSupported(req.(RequestMessage)) // panic is OK here for now
var err error
// verify request signatures
if err = signature.VerifyServiceMessage(req); err != nil {
err = fmt.Errorf("could not verify request: %w", err)
} else {
err = s.send(req)
}
if err != nil {
if !s.statusSupported {
return err
}
s.sendErr = err
return ErrAbortStream
}
return nil
}
func (s *RequestMessageStreamer) CloseAndRecv() (ResponseMessage, error) {
var (
resp ResponseMessage
err error
)
if s.sendErr != nil {
err = s.sendErr
} else {
resp, err = s.close()
if err != nil {
err = fmt.Errorf("could not close stream and receive response: %w", err)
}
}
if err != nil {
if !s.statusSupported {
return nil, err
}
resp = s.respCons()
setStatusV2(resp, err)
}
if err = signResponse(s.key, resp, s.statusSupported); err != nil {
return nil, err
}
return resp, nil
}
func (s *SignService) CreateRequestStreamer(sender RequestMessageWriter, closer ClientStreamCloser, blankResp ResponseConstructor) *RequestMessageStreamer {
return &RequestMessageStreamer{
key: s.key,
send: sender,
close: closer,
respCons: blankResp,
}
}
func (s *SignService) HandleServerStreamRequest(
req interface{},
respWriter ResponseMessageWriter,
blankResp ResponseConstructor,
respWriterCaller func(ResponseMessageWriter) error,
) error {
// handle protocol versions <=2.10 (API statuses was introduced in 2.11 only)
// req argument should be strengthen with type RequestMessage
statusSupported := isStatusSupported(req.(RequestMessage)) // panic is OK here for now
var err error
// verify request signatures
if err = signature.VerifyServiceMessage(req); err != nil {
err = fmt.Errorf("could not verify request: %w", err)
} else {
err = respWriterCaller(func(resp ResponseMessage) error {
if err := signResponse(s.key, resp, statusSupported); err != nil {
return err
}
return respWriter(resp)
})
}
if err != nil {
if !statusSupported {
return err
}
resp := blankResp()
setStatusV2(resp, err)
_ = signResponse(s.key, resp, false) // panics or returns nil with false arg
return respWriter(resp)
}
return nil
}
func (s *SignService) HandleUnaryRequest(ctx context.Context, req interface{}, handler UnaryHandler, blankResp ResponseConstructor) (ResponseMessage, error) {
// handle protocol versions <=2.10 (API statuses was introduced in 2.11 only)
// req argument should be strengthen with type RequestMessage
statusSupported := isStatusSupported(req.(RequestMessage)) // panic is OK here for now
var (
resp ResponseMessage
err error
)
// verify request signatures
if err = signature.VerifyServiceMessage(req); err != nil {
err = fmt.Errorf("could not verify request: %w", err)
} else {
// process request
resp, err = handler(ctx, req)
}
if err != nil {
if !statusSupported {
return nil, err
}
resp = blankResp()
setStatusV2(resp, err)
}
// sign the response
if err = signResponse(s.key, resp, statusSupported); err != nil {
return nil, err
}
return resp, nil
}
func isStatusSupported(req RequestMessage) bool {
version := req.GetMetaHeader().GetVersion()
mjr := version.GetMajor()
return mjr > 2 || mjr == 2 && version.GetMinor() >= 11
}
func setStatusV2(resp ResponseMessage, err error) {
// unwrap error
for e := errors.Unwrap(err); e != nil; e = errors.Unwrap(err) {
err = e
}
session.SetStatus(resp, apistatus.ToStatusV2(apistatus.ErrToStatus(err)))
}
// signs response with private key via signature.SignServiceMessage.
// The signature error affects the result depending on the protocol version:
// * if status return is supported, panics since we cannot return the failed status, because it will not be signed;
// * otherwise, returns error in order to transport it directly.
func signResponse(key *ecdsa.PrivateKey, resp interface{}, statusSupported bool) error {
err := signature.SignServiceMessage(key, resp)
if err != nil {
err = fmt.Errorf("could not sign response: %w", err)
if statusSupported {
// We can't pass this error as status code since response will be unsigned.
// Isn't expected in practice, so panic is ok here.
panic(err)
}
}
return err
}