package proxy import ( "github.com/tendermint/go-wire/data" "github.com/tendermint/tendermint/lite" certclient "github.com/tendermint/tendermint/lite/client" rpcclient "github.com/tendermint/tendermint/rpc/client" ctypes "github.com/tendermint/tendermint/rpc/core/types" ) var _ rpcclient.Client = Wrapper{} // Wrapper wraps a rpcclient with a Certifier 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.InquiringCertifier } // SecureClient uses a given certifier 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.InquiringCertifier) Wrapper { wrap := Wrapper{c, cert} // 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 data.Bytes, opts rpcclient.ABCIQueryOptions) (*ctypes.ResultABCIQuery, error) { res, _, err := GetWithProofOptions(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 data.Bytes) (*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 := int64(res.Height) check, err := GetCertifiedCommit(h, w.Client, w.cert) if err != nil { return res, err } err = res.Proof.Validate(check.Header.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 c, err := w.Commit(&meta.Header.Height) if err != nil { return nil, err } check := certclient.CommitFromResult(c) err = ValidateBlockMeta(meta, check) 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) { r, err := w.Client.Block(height) if err != nil { return nil, err } // get a checkpoint to verify from c, err := w.Commit(height) if err != nil { return nil, err } check := certclient.CommitFromResult(c) // now verify err = ValidateBlockMeta(r.BlockMeta, check) if err != nil { return nil, err } err = ValidateBlock(r.Block, check) if err != nil { return nil, err } return r, 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) { rpcclient.WaitForHeight(w.Client, *height, nil) r, err := w.Client.Commit(height) // if we got it, then certify it if err == nil { check := certclient.CommitFromResult(r) err = w.cert.Certify(check) } return r, err } // // 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.Unwrap().(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) // }