You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

255 lines
7.6 KiB

package proxy
import (
"context"
"github.com/tendermint/tendermint/crypto/merkle"
"github.com/tendermint/tendermint/libs/bytes"
"github.com/tendermint/tendermint/lite"
rpcclient "github.com/tendermint/tendermint/rpc/client"
ctypes "github.com/tendermint/tendermint/rpc/core/types"
rpctypes "github.com/tendermint/tendermint/rpc/jsonrpc/types"
)
var _ rpcclient.Client = Wrapper{}
// Wrapper wraps a rpcclient with a Verifier and double-checks any input that is
// provable before passing it along. Allows you to make any rpcclient fully secure.
type Wrapper struct {
rpcclient.Client
cert *lite.DynamicVerifier
prt *merkle.ProofRuntime
}
// SecureClient uses a given Verifier to wrap an connection to an untrusted
// host and return a cryptographically secure rpc client.
//
// If it is wrapping an HTTP rpcclient, it will also wrap the websocket interface
func SecureClient(c rpcclient.Client, cert *lite.DynamicVerifier) Wrapper {
prt := defaultProofRuntime()
wrap := Wrapper{c, cert, prt}
// TODO: no longer possible as no more such interface exposed....
// if we wrap http client, then we can swap out the event switch to filter
// if hc, ok := c.(*rpcclient.HTTP); ok {
// evt := hc.WSEvents.EventSwitch
// hc.WSEvents.EventSwitch = WrappedSwitch{evt, wrap}
// }
return wrap
}
// ABCIQueryWithOptions exposes all options for the ABCI query and verifies the returned proof
func (w Wrapper) ABCIQueryWithOptions(path string, data bytes.HexBytes,
opts rpcclient.ABCIQueryOptions) (*ctypes.ResultABCIQuery, error) {
res, err := GetWithProofOptions(w.prt, path, data, opts, w.Client, w.cert)
return res, err
}
// ABCIQuery uses default options for the ABCI query and verifies the returned proof
func (w Wrapper) ABCIQuery(path string, data bytes.HexBytes) (*ctypes.ResultABCIQuery, error) {
return w.ABCIQueryWithOptions(path, data, rpcclient.DefaultABCIQueryOptions)
}
// Tx queries for a given tx and verifies the proof if it was requested
func (w Wrapper) Tx(hash []byte, prove bool) (*ctypes.ResultTx, error) {
res, err := w.Client.Tx(hash, prove)
if !prove || err != nil {
return res, err
}
h := res.Height
sh, err := GetCertifiedCommit(h, w.Client, w.cert)
if err != nil {
return res, err
}
err = res.Proof.Validate(sh.DataHash)
return res, err
}
// BlockchainInfo requests a list of headers and verifies them all...
// Rather expensive.
//
// TODO: optimize this if used for anything needing performance
func (w Wrapper) BlockchainInfo(minHeight, maxHeight int64) (*ctypes.ResultBlockchainInfo, error) {
r, err := w.Client.BlockchainInfo(minHeight, maxHeight)
if err != nil {
return nil, err
}
// go and verify every blockmeta in the result....
for _, meta := range r.BlockMetas {
// get a checkpoint to verify from
res, err := w.Commit(&meta.Header.Height)
if err != nil {
return nil, err
}
sh := res.SignedHeader
err = ValidateBlockMeta(meta, sh)
if err != nil {
return nil, err
}
}
return r, nil
}
// Block returns an entire block and verifies all signatures
func (w Wrapper) Block(height *int64) (*ctypes.ResultBlock, error) {
resBlock, err := w.Client.Block(height)
if err != nil {
return nil, err
}
// get a checkpoint to verify from
resCommit, err := w.Commit(height)
if err != nil {
return nil, err
}
sh := resCommit.SignedHeader
err = ValidateBlock(resBlock.Block, sh)
if err != nil {
return nil, err
}
return resBlock, nil
}
// Commit downloads the Commit and certifies it with the lite.
//
// This is the foundation for all other verification in this module
func (w Wrapper) Commit(height *int64) (*ctypes.ResultCommit, error) {
if height == nil {
resStatus, err := w.Client.Status()
if err != nil {
return nil, err
}
// NOTE: If resStatus.CatchingUp, there is a race
// condition where the validator set for the next height
// isn't available until some time after the blockstore
// has height h on the remote node. This isn't an issue
// once the node has caught up, and a syncing node likely
// won't have this issue esp with the implementation we
// have here, but we may have to address this at some
// point.
height = new(int64)
*height = resStatus.SyncInfo.LatestBlockHeight
}
rpcclient.WaitForHeight(w.Client, *height, nil)
res, err := w.Client.Commit(height)
// if we got it, then verify it
if err == nil {
sh := res.SignedHeader
err = w.cert.Verify(sh)
}
return res, err
}
func (w Wrapper) RegisterOpDecoder(typ string, dec merkle.OpDecoder) {
w.prt.RegisterOpDecoder(typ, dec)
}
// SubscribeWS subscribes for events using the given query and remote address as
// a subscriber, but does not verify responses (UNSAFE)!
func (w Wrapper) SubscribeWS(ctx *rpctypes.Context, query string) (*ctypes.ResultSubscribe, error) {
out, err := w.Client.Subscribe(context.Background(), ctx.RemoteAddr(), query)
if err != nil {
return nil, err
}
go func() {
for {
select {
case resultEvent := <-out:
// XXX(melekes) We should have a switch here that performs a validation
// depending on the event's type.
ctx.WSConn.TryWriteRPCResponse(
rpctypes.NewRPCSuccessResponse(
ctx.WSConn.Codec(),
ctx.JSONReq.ID,
resultEvent,
))
case <-w.Client.Quit():
return
}
}
}()
return &ctypes.ResultSubscribe{}, nil
}
// UnsubscribeWS calls original client's Unsubscribe using remote address as a
// subscriber.
func (w Wrapper) UnsubscribeWS(ctx *rpctypes.Context, query string) (*ctypes.ResultUnsubscribe, error) {
err := w.Client.Unsubscribe(context.Background(), ctx.RemoteAddr(), query)
if err != nil {
return nil, err
}
return &ctypes.ResultUnsubscribe{}, nil
}
// UnsubscribeAllWS calls original client's UnsubscribeAll using remote address
// as a subscriber.
func (w Wrapper) UnsubscribeAllWS(ctx *rpctypes.Context) (*ctypes.ResultUnsubscribe, error) {
err := w.Client.UnsubscribeAll(context.Background(), ctx.RemoteAddr())
if err != nil {
return nil, err
}
return &ctypes.ResultUnsubscribe{}, nil
}
// // WrappedSwitch creates a websocket connection that auto-verifies any info
// // coming through before passing it along.
// //
// // Since the verification takes 1-2 rpc calls, this is obviously only for
// // relatively low-throughput situations that can tolerate a bit extra latency
// type WrappedSwitch struct {
// types.EventSwitch
// client rpcclient.Client
// }
// // FireEvent verifies any block or header returned from the eventswitch
// func (s WrappedSwitch) FireEvent(event string, data events.EventData) {
// tm, ok := data.(types.TMEventData)
// if !ok {
// fmt.Printf("bad type %#v\n", data)
// return
// }
// // check to validate it if possible, and drop if not valid
// switch t := tm.(type) {
// case types.EventDataNewBlockHeader:
// err := verifyHeader(s.client, t.Header)
// if err != nil {
// fmt.Printf("Invalid header: %#v\n", err)
// return
// }
// case types.EventDataNewBlock:
// err := verifyBlock(s.client, t.Block)
// if err != nil {
// fmt.Printf("Invalid block: %#v\n", err)
// return
// }
// // TODO: can we verify tx as well? anything else
// }
// // looks good, we fire it
// s.EventSwitch.FireEvent(event, data)
// }
// func verifyHeader(c rpcclient.Client, head *types.Header) error {
// // get a checkpoint to verify from
// commit, err := c.Commit(&head.Height)
// if err != nil {
// return err
// }
// check := certclient.CommitFromResult(commit)
// return ValidateHeader(head, check)
// }
//
// func verifyBlock(c rpcclient.Client, block *types.Block) error {
// // get a checkpoint to verify from
// commit, err := c.Commit(&block.Height)
// if err != nil {
// return err
// }
// check := certclient.CommitFromResult(commit)
// return ValidateBlock(block, check)
// }