privval: refactor Remote signers (#3370)

This PR is related to #3107 and a continuation of #3351

It is important to emphasise that in the privval original design, client/server and listening/dialing roles are inverted and do not follow a conventional interaction.

Given two hosts A and B:

    Host A is listener/client
    Host B is dialer/server (contains the secret key)
    When A requires a signature, it needs to wait for B to dial in before it can issue a request.
    A only accepts a single connection and any failure leads to dropping the connection and waiting for B to reconnect.

The original rationale behind this design was based on security.

    Host B only allows outbound connections to a list of whitelisted hosts.
    It is not possible to reach B unless B dials in. There are no listening/open ports in B.

This PR results in the following changes:

    Refactors ping/heartbeat to avoid previously existing race conditions.
    Separates transport (dialer/listener) from signing (client/server) concerns to simplify workflow.
    Unifies and abstracts away the differences between unix and tcp sockets.
    A single signer endpoint implementation unifies connection handling code (read/write/close/connection obj)
    The signer request handler (server side) is customizable to increase testability.
    Updates and extends unit tests

A high level overview of the classes is as follows:

Transport (endpoints): The following classes take care of establishing a connection

    SignerDialerEndpoint
    SignerListeningEndpoint
    SignerEndpoint groups common functionality (read/write/timeouts/etc.)

Signing (client/server): The following classes take care of exchanging request/responses

    SignerClient
    SignerServer

This PR also closes #3601

Commits:

* refactoring - work in progress

* reworking unit tests

* Encapsulating and fixing unit tests

* Improve tests

* Clean up

* Fix/improve unit tests

* clean up tests

* Improving service endpoint

* fixing unit test

* fix linter issues

* avoid invalid cache values (improve later?)

* complete implementation

* wip

* improved connection loop

* Improve reconnections + fixing unit tests

* addressing comments

* small formatting changes

* clean up

* Update node/node.go

Co-Authored-By: jleni <juan.leni@zondax.ch>

* Update privval/signer_client.go

Co-Authored-By: jleni <juan.leni@zondax.ch>

* Update privval/signer_client_test.go

Co-Authored-By: jleni <juan.leni@zondax.ch>

* check during initialization

* dropping connecting when writing fails

* removing break

* use t.log instead

* unifying and using cmn.GetFreePort()

* review fixes

* reordering and unifying drop connection

* closing instead of signalling

* refactored service loop

* removed superfluous brackets

* GetPubKey can return errors

* Revert "GetPubKey can return errors"

This reverts commit 68c06f19b4.

* adding entry to changelog

* Update CHANGELOG_PENDING.md

Co-Authored-By: jleni <juan.leni@zondax.ch>

* Update privval/signer_client.go

Co-Authored-By: jleni <juan.leni@zondax.ch>

* Update privval/signer_dialer_endpoint.go

Co-Authored-By: jleni <juan.leni@zondax.ch>

* Update privval/signer_dialer_endpoint.go

Co-Authored-By: jleni <juan.leni@zondax.ch>

* Update privval/signer_dialer_endpoint.go

Co-Authored-By: jleni <juan.leni@zondax.ch>

* Update privval/signer_dialer_endpoint.go

Co-Authored-By: jleni <juan.leni@zondax.ch>

* Update privval/signer_listener_endpoint_test.go

Co-Authored-By: jleni <juan.leni@zondax.ch>

* updating node.go

* review fixes

* fixes linter

* fixing unit test

* small fixes in comments

* addressing review comments

* addressing review comments 2

* reverting suggestion

* Update privval/signer_client_test.go

Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>

* Update privval/signer_client_test.go

Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>

* Update privval/signer_listener_endpoint_test.go

Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>

* do not expose brokenSignerDialerEndpoint

* clean up logging

* unifying methods

shorten test time
signer also drops

* reenabling pings

* improving testability + unit test

* fixing go fmt + unit test

* remove unused code

* Addressing review comments

* simplifying connection workflow

* fix linter/go import issue

* using base service quit

* updating comment

* Simplifying design + adjusting names

* fixing linter issues

* refactoring test harness + fixes

* Addressing review comments

* cleaning up

* adding additional error check

.gitignore

@@ -43,3 +43,5 @@ terraform.tfstate.backup
 terraform.tfstate.d
 
 .vscode
+
+profile\.out

CHANGELOG_PENDING.md

@@ -19,6 +19,7 @@ program](https://hackerone.com/tendermint).
 
 ### IMPROVEMENTS:
 
+- [privval] \#3370 Refactors and simplifies validator/kms connection handling. Please refer to thttps://github.com/tendermint/tendermint/pull/3370#issue-257360971
 - [consensus] \#3839 Reduce "Error attempting to add vote" message severity (Error -> Info)
 
 ### BUG FIXES:

cmd/priv_val_server/main.go

@@ -48,15 +48,17 @@ func main() {
 		os.Exit(1)
 	}
 
-	rs := privval.NewSignerServiceEndpoint(logger, *chainID, pv, dialer)
-	err := rs.Start()
+	sd := privval.NewSignerDialerEndpoint(logger, dialer)
+	ss := privval.NewSignerServer(sd, *chainID, pv)
+
+	err := ss.Start()
 	if err != nil {
 		panic(err)
 	}
 
 	// Stop upon receiving SIGTERM or CTRL-C.
 	cmn.TrapSignal(logger, func() {
-		err := rs.Stop()
+		err := ss.Stop()
 		if err != nil {
 			panic(err)
 		}

node/node.go

@@ -23,7 +23,7 @@ import (
 	cfg "github.com/tendermint/tendermint/config"
 	"github.com/tendermint/tendermint/consensus"
 	cs "github.com/tendermint/tendermint/consensus"
-	"github.com/tendermint/tendermint/crypto/ed25519"
+	"github.com/tendermint/tendermint/crypto"
 	"github.com/tendermint/tendermint/evidence"
 	cmn "github.com/tendermint/tendermint/libs/common"
 	"github.com/tendermint/tendermint/libs/log"
@@ -278,9 +278,7 @@ func doHandshake(stateDB dbm.DB, state sm.State, blockStore sm.BlockStore,
 	return nil
 }
 
-func logNodeStartupInfo(state sm.State, privValidator types.PrivValidator, logger,
-	consensusLogger log.Logger) {
-
+func logNodeStartupInfo(state sm.State, pubKey crypto.PubKey, logger, consensusLogger log.Logger) {
 	// Log the version info.
 	logger.Info("Version info",
 		"software", version.TMCoreSemVer,
@@ -296,7 +294,6 @@ func logNodeStartupInfo(state sm.State, privValidator types.PrivValidator, logge
 		)
 	}
 
-	pubKey := privValidator.GetPubKey()
 	addr := pubKey.Address()
 	// Log whether this node is a validator or an observer
 	if state.Validators.HasAddress(addr) {
@@ -601,7 +598,13 @@ func NewNode(config *cfg.Config,
 		}
 	}
 
-	logNodeStartupInfo(state, privValidator, logger, consensusLogger)
+	pubKey := privValidator.GetPubKey()
+	if pubKey == nil {
+		// TODO: GetPubKey should return errors - https://github.com/tendermint/tendermint/issues/3602
+		return nil, errors.New("could not retrieve public key from private validator")
+	}
+
+	logNodeStartupInfo(state, pubKey, logger, consensusLogger)
 
 	// Decide whether to fast-sync or not
 	// We don't fast-sync when the only validator is us.
@@ -1158,29 +1161,13 @@ func createAndStartPrivValidatorSocketClient(
 	listenAddr string,
 	logger log.Logger,
 ) (types.PrivValidator, error) {
-	var listener net.Listener
-
-	protocol, address := cmn.ProtocolAndAddress(listenAddr)
-	ln, err := net.Listen(protocol, address)
+	pve, err := privval.NewSignerListener(listenAddr, logger)
 	if err != nil {
-		return nil, err
-	}
-	switch protocol {
-	case "unix":
-		listener = privval.NewUnixListener(ln)
-	case "tcp":
-		// TODO: persist this key so external signer
-		// can actually authenticate us
-		listener = privval.NewTCPListener(ln, ed25519.GenPrivKey())
-	default:
-		return nil, fmt.Errorf(
-			"wrong listen address: expected either 'tcp' or 'unix' protocols, got %s",
-			protocol,
-		)
+		return nil, errors.Wrap(err, "failed to start private validator")
 	}
 
-	pvsc := privval.NewSignerValidatorEndpoint(logger.With("module", "privval"), listener)
-	if err := pvsc.Start(); err != nil {
+	pvsc, err := privval.NewSignerClient(pve)
+	if err != nil {
 		return nil, errors.Wrap(err, "failed to start private validator")
 	}
 

node/node_test.go

@@ -136,25 +136,29 @@ func TestNodeSetPrivValTCP(t *testing.T) {
 	config.BaseConfig.PrivValidatorListenAddr = addr
 
 	dialer := privval.DialTCPFn(addr, 100*time.Millisecond, ed25519.GenPrivKey())
-	pvsc := privval.NewSignerServiceEndpoint(
+	dialerEndpoint := privval.NewSignerDialerEndpoint(
 		log.TestingLogger(),
+		dialer,
+	)
+	privval.SignerDialerEndpointTimeoutReadWrite(100 * time.Millisecond)(dialerEndpoint)
+
+	signerServer := privval.NewSignerServer(
+		dialerEndpoint,
 		config.ChainID(),
 		types.NewMockPV(),
-		dialer,
 	)
-	privval.SignerServiceEndpointTimeoutReadWrite(100 * time.Millisecond)(pvsc)
 
 	go func() {
-		err := pvsc.Start()
+		err := signerServer.Start()
 		if err != nil {
 			panic(err)
 		}
 	}()
-	defer pvsc.Stop()
+	defer signerServer.Stop()
 
 	n, err := DefaultNewNode(config, log.TestingLogger())
 	require.NoError(t, err)
-	assert.IsType(t, &privval.SignerValidatorEndpoint{}, n.PrivValidator())
+	assert.IsType(t, &privval.SignerClient{}, n.PrivValidator())
 }
 
 // address without a protocol must result in error
@@ -178,13 +182,17 @@ func TestNodeSetPrivValIPC(t *testing.T) {
 	config.BaseConfig.PrivValidatorListenAddr = "unix://" + tmpfile
 
 	dialer := privval.DialUnixFn(tmpfile)
-	pvsc := privval.NewSignerServiceEndpoint(
+	dialerEndpoint := privval.NewSignerDialerEndpoint(
 		log.TestingLogger(),
+		dialer,
+	)
+	privval.SignerDialerEndpointTimeoutReadWrite(100 * time.Millisecond)(dialerEndpoint)
+
+	pvsc := privval.NewSignerServer(
+		dialerEndpoint,
 		config.ChainID(),
 		types.NewMockPV(),
-		dialer,
 	)
-	privval.SignerServiceEndpointTimeoutReadWrite(100 * time.Millisecond)(pvsc)
 
 	go func() {
 		err := pvsc.Start()
@@ -194,8 +202,7 @@ func TestNodeSetPrivValIPC(t *testing.T) {
 
 	n, err := DefaultNewNode(config, log.TestingLogger())
 	require.NoError(t, err)
-	assert.IsType(t, &privval.SignerValidatorEndpoint{}, n.PrivValidator())
-
+	assert.IsType(t, &privval.SignerClient{}, n.PrivValidator())
 }
 
 // testFreeAddr claims a free port so we don't block on listener being ready.

privval/doc.go

@@ -6,16 +6,16 @@ FilePV
 
 FilePV is the simplest implementation and developer default. It uses one file for the private key and another to store state.
 
-SignerValidatorEndpoint
+SignerListenerEndpoint
 
-SignerValidatorEndpoint establishes a connection to an external process, like a Key Management Server (KMS), using a socket.
-SignerValidatorEndpoint listens for the external KMS process to dial in.
-SignerValidatorEndpoint takes a listener, which determines the type of connection
+SignerListenerEndpoint establishes a connection to an external process, like a Key Management Server (KMS), using a socket.
+SignerListenerEndpoint listens for the external KMS process to dial in.
+SignerListenerEndpoint takes a listener, which determines the type of connection
 (ie. encrypted over tcp, or unencrypted over unix).
 
-SignerServiceEndpoint
+SignerDialerEndpoint
 
-SignerServiceEndpoint is a simple wrapper around a net.Conn. It's used by both IPCVal and TCPVal.
+SignerDialerEndpoint is a simple wrapper around a net.Conn. It's used by both IPCVal and TCPVal.
 
 */
 package privval

privval/errors.go

@@ -4,10 +4,21 @@ import (
 	"fmt"
 )
 
+type EndpointTimeoutError struct{}
+
+// Implement the net.Error interface.
+func (e EndpointTimeoutError) Error() string   { return "endpoint connection timed out" }
+func (e EndpointTimeoutError) Timeout() bool   { return true }
+func (e EndpointTimeoutError) Temporary() bool { return true }
+
 // Socket errors.
 var (
 	ErrUnexpectedResponse = fmt.Errorf("received unexpected response")
-	ErrConnTimeout        = fmt.Errorf("remote signer timed out")
+	ErrNoConnection       = fmt.Errorf("endpoint is not connected")
+	ErrConnectionTimeout  = EndpointTimeoutError{}
+
+	ErrReadTimeout  = fmt.Errorf("endpoint read timed out")
+	ErrWriteTimeout = fmt.Errorf("endpoint write timed out")
 )
 
 // RemoteSignerError allows (remote) validators to include meaningful error descriptions in their reply.
@@ -18,5 +29,5 @@ type RemoteSignerError struct {
 }
 
 func (e *RemoteSignerError) Error() string {
-	return fmt.Sprintf("signerServiceEndpoint returned error #%d: %s", e.Code, e.Description)
+	return fmt.Sprintf("signerEndpoint returned error #%d: %s", e.Code, e.Description)
 }

privval/file_deprecated_test.go

@@ -67,11 +67,11 @@ func assertEqualPV(t *testing.T, oldPV *privval.OldFilePV, newPV *privval.FilePV
 }
 
 func initTmpOldFile(t *testing.T) string {
-	tmpfile, err := ioutil.TempFile("", "priv_validator_*.json")
+	tmpFile, err := ioutil.TempFile("", "priv_validator_*.json")
 	require.NoError(t, err)
-	t.Logf("created test file %s", tmpfile.Name())
-	_, err = tmpfile.WriteString(oldPrivvalContent)
+	t.Logf("created test file %s", tmpFile.Name())
+	_, err = tmpFile.WriteString(oldPrivvalContent)
 	require.NoError(t, err)
 
-	return tmpfile.Name()
+	return tmpFile.Name()
 }

privval/file_test.go

@@ -58,7 +58,7 @@ func TestResetValidator(t *testing.T) {
 	// priv val after signing is not same as empty
 	assert.NotEqual(t, privVal.LastSignState, emptyState)
 
-	// priv val after reset is same as empty
+	// priv val after AcceptNewConnection is same as empty
 	privVal.Reset()
 	assert.Equal(t, privVal.LastSignState, emptyState)
 }
@@ -164,6 +164,7 @@ func TestSignVote(t *testing.T) {
 
 	block1 := types.BlockID{Hash: []byte{1, 2, 3}, PartsHeader: types.PartSetHeader{}}
 	block2 := types.BlockID{Hash: []byte{3, 2, 1}, PartsHeader: types.PartSetHeader{}}
+
 	height, round := int64(10), 1
 	voteType := byte(types.PrevoteType)
 

privval/messages.go

@@ -1,61 +1,64 @@
 package privval
 
 import (
-	amino "github.com/tendermint/go-amino"
+	"github.com/tendermint/go-amino"
 	"github.com/tendermint/tendermint/crypto"
 	"github.com/tendermint/tendermint/types"
 )
 
-// RemoteSignerMsg is sent between SignerServiceEndpoint and the SignerServiceEndpoint client.
-type RemoteSignerMsg interface{}
+// SignerMessage is sent between Signer Clients and Servers.
+type SignerMessage interface{}
 
 func RegisterRemoteSignerMsg(cdc *amino.Codec) {
-	cdc.RegisterInterface((*RemoteSignerMsg)(nil), nil)
+	cdc.RegisterInterface((*SignerMessage)(nil), nil)
 	cdc.RegisterConcrete(&PubKeyRequest{}, "tendermint/remotesigner/PubKeyRequest", nil)
 	cdc.RegisterConcrete(&PubKeyResponse{}, "tendermint/remotesigner/PubKeyResponse", nil)
 	cdc.RegisterConcrete(&SignVoteRequest{}, "tendermint/remotesigner/SignVoteRequest", nil)
 	cdc.RegisterConcrete(&SignedVoteResponse{}, "tendermint/remotesigner/SignedVoteResponse", nil)
 	cdc.RegisterConcrete(&SignProposalRequest{}, "tendermint/remotesigner/SignProposalRequest", nil)
 	cdc.RegisterConcrete(&SignedProposalResponse{}, "tendermint/remotesigner/SignedProposalResponse", nil)
+
 	cdc.RegisterConcrete(&PingRequest{}, "tendermint/remotesigner/PingRequest", nil)
 	cdc.RegisterConcrete(&PingResponse{}, "tendermint/remotesigner/PingResponse", nil)
 }
 
+// TODO: Add ChainIDRequest
+
 // PubKeyRequest requests the consensus public key from the remote signer.
 type PubKeyRequest struct{}
 
-// PubKeyResponse is a PrivValidatorSocket message containing the public key.
+// PubKeyResponse is a response message containing the public key.
 type PubKeyResponse struct {
 	PubKey crypto.PubKey
 	Error  *RemoteSignerError
 }
 
-// SignVoteRequest is a PrivValidatorSocket message containing a vote.
+// SignVoteRequest is a request to sign a vote
 type SignVoteRequest struct {
 	Vote *types.Vote
 }
 
-// SignedVoteResponse is a PrivValidatorSocket message containing a signed vote along with a potenial error message.
+// SignedVoteResponse is a response containing a signed vote or an error
 type SignedVoteResponse struct {
 	Vote  *types.Vote
 	Error *RemoteSignerError
 }
 
-// SignProposalRequest is a PrivValidatorSocket message containing a Proposal.
+// SignProposalRequest is a request to sign a proposal
 type SignProposalRequest struct {
 	Proposal *types.Proposal
 }
 
-// SignedProposalResponse is a PrivValidatorSocket message containing a proposal response
+// SignedProposalResponse is response containing a signed proposal or an error
 type SignedProposalResponse struct {
 	Proposal *types.Proposal
 	Error    *RemoteSignerError
 }
 
-// PingRequest is a PrivValidatorSocket message to keep the connection alive.
+// PingRequest is a request to confirm that the connection is alive.
 type PingRequest struct {
 }
 
-// PingRequest is a PrivValidatorSocket response to keep the connection alive.
+// PingResponse is a response to confirm that the connection is alive.
 type PingResponse struct {
 }

privval/signer_client.go

@@ -0,0 +1,131 @@
+package privval
+
+import (
+	"time"
+
+	"github.com/pkg/errors"
+
+	"github.com/tendermint/tendermint/crypto"
+	"github.com/tendermint/tendermint/types"
+)
+
+// SignerClient implements PrivValidator.
+// Handles remote validator connections that provide signing services
+type SignerClient struct {
+	endpoint *SignerListenerEndpoint
+}
+
+var _ types.PrivValidator = (*SignerClient)(nil)
+
+// NewSignerClient returns an instance of SignerClient.
+// it will start the endpoint (if not already started)
+func NewSignerClient(endpoint *SignerListenerEndpoint) (*SignerClient, error) {
+	if !endpoint.IsRunning() {
+		if err := endpoint.Start(); err != nil {
+			return nil, errors.Wrap(err, "failed to start listener endpoint")
+		}
+	}
+
+	return &SignerClient{endpoint: endpoint}, nil
+}
+
+// Close closes the underlying connection
+func (sc *SignerClient) Close() error {
+	return sc.endpoint.Close()
+}
+
+// IsConnected indicates with the signer is connected to a remote signing service
+func (sc *SignerClient) IsConnected() bool {
+	return sc.endpoint.IsConnected()
+}
+
+// WaitForConnection waits maxWait for a connection or returns a timeout error
+func (sc *SignerClient) WaitForConnection(maxWait time.Duration) error {
+	return sc.endpoint.WaitForConnection(maxWait)
+}
+
+//--------------------------------------------------------
+// Implement PrivValidator
+
+// Ping sends a ping request to the remote signer
+func (sc *SignerClient) Ping() error {
+	response, err := sc.endpoint.SendRequest(&PingRequest{})
+
+	if err != nil {
+		sc.endpoint.Logger.Error("SignerClient::Ping", "err", err)
+		return nil
+	}
+
+	_, ok := response.(*PingResponse)
+	if !ok {
+		sc.endpoint.Logger.Error("SignerClient::Ping", "err", "response != PingResponse")
+		return err
+	}
+
+	return nil
+}
+
+// GetPubKey retrieves a public key from a remote signer
+func (sc *SignerClient) GetPubKey() crypto.PubKey {
+	response, err := sc.endpoint.SendRequest(&PubKeyRequest{})
+	if err != nil {
+		sc.endpoint.Logger.Error("SignerClient::GetPubKey", "err", err)
+		return nil
+	}
+
+	pubKeyResp, ok := response.(*PubKeyResponse)
+	if !ok {
+		sc.endpoint.Logger.Error("SignerClient::GetPubKey", "err", "response != PubKeyResponse")
+		return nil
+	}
+
+	if pubKeyResp.Error != nil {
+		sc.endpoint.Logger.Error("failed to get private validator's public key", "err", pubKeyResp.Error)
+		return nil
+	}
+
+	return pubKeyResp.PubKey
+}
+
+// SignVote requests a remote signer to sign a vote
+func (sc *SignerClient) SignVote(chainID string, vote *types.Vote) error {
+	response, err := sc.endpoint.SendRequest(&SignVoteRequest{Vote: vote})
+	if err != nil {
+		sc.endpoint.Logger.Error("SignerClient::SignVote", "err", err)
+		return err
+	}
+
+	resp, ok := response.(*SignedVoteResponse)
+	if !ok {
+		sc.endpoint.Logger.Error("SignerClient::GetPubKey", "err", "response != SignedVoteResponse")
+		return ErrUnexpectedResponse
+	}
+
+	if resp.Error != nil {
+		return resp.Error
+	}
+	*vote = *resp.Vote
+
+	return nil
+}
+
+// SignProposal requests a remote signer to sign a proposal
+func (sc *SignerClient) SignProposal(chainID string, proposal *types.Proposal) error {
+	response, err := sc.endpoint.SendRequest(&SignProposalRequest{Proposal: proposal})
+	if err != nil {
+		sc.endpoint.Logger.Error("SignerClient::SignProposal", "err", err)
+		return err
+	}
+
+	resp, ok := response.(*SignedProposalResponse)
+	if !ok {
+		sc.endpoint.Logger.Error("SignerClient::SignProposal", "err", "response != SignedProposalResponse")
+		return ErrUnexpectedResponse
+	}
+	if resp.Error != nil {
+		return resp.Error
+	}
+	*proposal = *resp.Proposal
+
+	return nil
+}

privval/signer_client_test.go

@@ -0,0 +1,257 @@
+package privval
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/tendermint/tendermint/libs/common"
+	"github.com/tendermint/tendermint/types"
+)
+
+type signerTestCase struct {
+	chainID      string
+	mockPV       types.PrivValidator
+	signerClient *SignerClient
+	signerServer *SignerServer
+}
+
+func getSignerTestCases(t *testing.T) []signerTestCase {
+	testCases := make([]signerTestCase, 0)
+
+	// Get test cases for each possible dialer (DialTCP / DialUnix / etc)
+	for _, dtc := range getDialerTestCases(t) {
+		chainID := common.RandStr(12)
+		mockPV := types.NewMockPV()
+
+		// get a pair of signer listener, signer dialer endpoints
+		sl, sd := getMockEndpoints(t, dtc.addr, dtc.dialer)
+		sc, err := NewSignerClient(sl)
+		require.NoError(t, err)
+		ss := NewSignerServer(sd, chainID, mockPV)
+
+		err = ss.Start()
+		require.NoError(t, err)
+
+		tc := signerTestCase{
+			chainID:      chainID,
+			mockPV:       mockPV,
+			signerClient: sc,
+			signerServer: ss,
+		}
+
+		testCases = append(testCases, tc)
+	}
+
+	return testCases
+}
+
+func TestSignerClose(t *testing.T) {
+	for _, tc := range getSignerTestCases(t) {
+		err := tc.signerClient.Close()
+		assert.NoError(t, err)
+
+		err = tc.signerServer.Stop()
+		assert.NoError(t, err)
+	}
+}
+
+func TestSignerPing(t *testing.T) {
+	for _, tc := range getSignerTestCases(t) {
+		defer tc.signerServer.Stop()
+		defer tc.signerClient.Close()
+
+		err := tc.signerClient.Ping()
+		assert.NoError(t, err)
+	}
+}
+
+func TestSignerGetPubKey(t *testing.T) {
+	for _, tc := range getSignerTestCases(t) {
+		defer tc.signerServer.Stop()
+		defer tc.signerClient.Close()
+
+		pubKey := tc.signerClient.GetPubKey()
+		expectedPubKey := tc.mockPV.GetPubKey()
+
+		assert.Equal(t, expectedPubKey, pubKey)
+
+		addr := tc.signerClient.GetPubKey().Address()
+		expectedAddr := tc.mockPV.GetPubKey().Address()
+
+		assert.Equal(t, expectedAddr, addr)
+	}
+}
+
+func TestSignerProposal(t *testing.T) {
+	for _, tc := range getSignerTestCases(t) {
+		ts := time.Now()
+		want := &types.Proposal{Timestamp: ts}
+		have := &types.Proposal{Timestamp: ts}
+
+		defer tc.signerServer.Stop()
+		defer tc.signerClient.Close()
+
+		require.NoError(t, tc.mockPV.SignProposal(tc.chainID, want))
+		require.NoError(t, tc.signerClient.SignProposal(tc.chainID, have))
+
+		assert.Equal(t, want.Signature, have.Signature)
+	}
+}
+
+func TestSignerVote(t *testing.T) {
+	for _, tc := range getSignerTestCases(t) {
+		ts := time.Now()
+		want := &types.Vote{Timestamp: ts, Type: types.PrecommitType}
+		have := &types.Vote{Timestamp: ts, Type: types.PrecommitType}
+
+		defer tc.signerServer.Stop()
+		defer tc.signerClient.Close()
+
+		require.NoError(t, tc.mockPV.SignVote(tc.chainID, want))
+		require.NoError(t, tc.signerClient.SignVote(tc.chainID, have))
+
+		assert.Equal(t, want.Signature, have.Signature)
+	}
+}
+
+func TestSignerVoteResetDeadline(t *testing.T) {
+	for _, tc := range getSignerTestCases(t) {
+		ts := time.Now()
+		want := &types.Vote{Timestamp: ts, Type: types.PrecommitType}
+		have := &types.Vote{Timestamp: ts, Type: types.PrecommitType}
+
+		defer tc.signerServer.Stop()
+		defer tc.signerClient.Close()
+
+		time.Sleep(testTimeoutReadWrite2o3)
+
+		require.NoError(t, tc.mockPV.SignVote(tc.chainID, want))
+		require.NoError(t, tc.signerClient.SignVote(tc.chainID, have))
+		assert.Equal(t, want.Signature, have.Signature)
+
+		// TODO(jleni): Clarify what is actually being tested
+
+		// This would exceed the deadline if it was not extended by the previous message
+		time.Sleep(testTimeoutReadWrite2o3)
+
+		require.NoError(t, tc.mockPV.SignVote(tc.chainID, want))
+		require.NoError(t, tc.signerClient.SignVote(tc.chainID, have))
+		assert.Equal(t, want.Signature, have.Signature)
+	}
+}
+
+func TestSignerVoteKeepAlive(t *testing.T) {
+	for _, tc := range getSignerTestCases(t) {
+		ts := time.Now()
+		want := &types.Vote{Timestamp: ts, Type: types.PrecommitType}
+		have := &types.Vote{Timestamp: ts, Type: types.PrecommitType}
+
+		defer tc.signerServer.Stop()
+		defer tc.signerClient.Close()
+
+		// Check that even if the client does not request a
+		// signature for a long time. The service is still available
+
+		// in this particular case, we use the dialer logger to ensure that
+		// test messages are properly interleaved in the test logs
+		tc.signerServer.Logger.Debug("TEST: Forced Wait -------------------------------------------------")
+		time.Sleep(testTimeoutReadWrite * 3)
+		tc.signerServer.Logger.Debug("TEST: Forced Wait DONE---------------------------------------------")
+
+		require.NoError(t, tc.mockPV.SignVote(tc.chainID, want))
+		require.NoError(t, tc.signerClient.SignVote(tc.chainID, have))
+
+		assert.Equal(t, want.Signature, have.Signature)
+	}
+}
+
+func TestSignerSignProposalErrors(t *testing.T) {
+	for _, tc := range getSignerTestCases(t) {
+		// Replace service with a mock that always fails
+		tc.signerServer.privVal = types.NewErroringMockPV()
+		tc.mockPV = types.NewErroringMockPV()
+
+		defer tc.signerServer.Stop()
+		defer tc.signerClient.Close()
+
+		ts := time.Now()
+		proposal := &types.Proposal{Timestamp: ts}
+		err := tc.signerClient.SignProposal(tc.chainID, proposal)
+		require.Equal(t, err.(*RemoteSignerError).Description, types.ErroringMockPVErr.Error())
+
+		err = tc.mockPV.SignProposal(tc.chainID, proposal)
+		require.Error(t, err)
+
+		err = tc.signerClient.SignProposal(tc.chainID, proposal)
+		require.Error(t, err)
+	}
+}
+
+func TestSignerSignVoteErrors(t *testing.T) {
+	for _, tc := range getSignerTestCases(t) {
+		ts := time.Now()
+		vote := &types.Vote{Timestamp: ts, Type: types.PrecommitType}
+
+		// Replace signer service privval with one that always fails
+		tc.signerServer.privVal = types.NewErroringMockPV()
+		tc.mockPV = types.NewErroringMockPV()
+
+		defer tc.signerServer.Stop()
+		defer tc.signerClient.Close()
+
+		err := tc.signerClient.SignVote(tc.chainID, vote)
+		require.Equal(t, err.(*RemoteSignerError).Description, types.ErroringMockPVErr.Error())
+
+		err = tc.mockPV.SignVote(tc.chainID, vote)
+		require.Error(t, err)
+
+		err = tc.signerClient.SignVote(tc.chainID, vote)
+		require.Error(t, err)
+	}
+}
+
+func brokenHandler(privVal types.PrivValidator, request SignerMessage, chainID string) (SignerMessage, error) {
+	var res SignerMessage
+	var err error
+
+	switch r := request.(type) {
+
+	// This is broken and will answer most requests with a pubkey response
+	case *PubKeyRequest:
+		res = &PubKeyResponse{nil, nil}
+	case *SignVoteRequest:
+		res = &PubKeyResponse{nil, nil}
+	case *SignProposalRequest:
+		res = &PubKeyResponse{nil, nil}
+
+	case *PingRequest:
+		err, res = nil, &PingResponse{}
+
+	default:
+		err = fmt.Errorf("unknown msg: %v", r)
+	}
+
+	return res, err
+}
+
+func TestSignerUnexpectedResponse(t *testing.T) {
+	for _, tc := range getSignerTestCases(t) {
+		tc.signerServer.privVal = types.NewMockPV()
+		tc.mockPV = types.NewMockPV()
+
+		tc.signerServer.SetRequestHandler(brokenHandler)
+
+		defer tc.signerServer.Stop()
+		defer tc.signerClient.Close()
+
+		ts := time.Now()
+		want := &types.Vote{Timestamp: ts, Type: types.PrecommitType}
+
+		e := tc.signerClient.SignVote(tc.chainID, want)
+		assert.EqualError(t, e, "received unexpected response")
+	}
+}

privval/signer_dialer_endpoint.go

@@ -0,0 +1,84 @@
+package privval
+
+import (
+	"time"
+
+	cmn "github.com/tendermint/tendermint/libs/common"
+	"github.com/tendermint/tendermint/libs/log"
+)
+
+const (
+	defaultMaxDialRetries        = 10
+	defaultRetryWaitMilliseconds = 100
+)
+
+// SignerServiceEndpointOption sets an optional parameter on the SignerDialerEndpoint.
+type SignerServiceEndpointOption func(*SignerDialerEndpoint)
+
+// SignerDialerEndpointTimeoutReadWrite sets the read and write timeout for connections
+// from external signing processes.
+func SignerDialerEndpointTimeoutReadWrite(timeout time.Duration) SignerServiceEndpointOption {
+	return func(ss *SignerDialerEndpoint) { ss.timeoutReadWrite = timeout }
+}
+
+// SignerDialerEndpointConnRetries sets the amount of attempted retries to acceptNewConnection.
+func SignerDialerEndpointConnRetries(retries int) SignerServiceEndpointOption {
+	return func(ss *SignerDialerEndpoint) { ss.maxConnRetries = retries }
+}
+
+// SignerDialerEndpoint dials using its dialer and responds to any
+// signature requests using its privVal.
+type SignerDialerEndpoint struct {
+	signerEndpoint
+
+	dialer SocketDialer
+
+	retryWait      time.Duration
+	maxConnRetries int
+}
+
+// NewSignerDialerEndpoint returns a SignerDialerEndpoint that will dial using the given
+// dialer and respond to any signature requests over the connection
+// using the given privVal.
+func NewSignerDialerEndpoint(
+	logger log.Logger,
+	dialer SocketDialer,
+) *SignerDialerEndpoint {
+
+	sd := &SignerDialerEndpoint{
+		dialer:         dialer,
+		retryWait:      defaultRetryWaitMilliseconds * time.Millisecond,
+		maxConnRetries: defaultMaxDialRetries,
+	}
+
+	sd.BaseService = *cmn.NewBaseService(logger, "SignerDialerEndpoint", sd)
+	sd.signerEndpoint.timeoutReadWrite = defaultTimeoutReadWriteSeconds * time.Second
+
+	return sd
+}
+
+func (sd *SignerDialerEndpoint) ensureConnection() error {
+	if sd.IsConnected() {
+		return nil
+	}
+
+	retries := 0
+	for retries < sd.maxConnRetries {
+		conn, err := sd.dialer()
+
+		if err != nil {
+			retries++
+			sd.Logger.Debug("SignerDialer: Reconnection failed", "retries", retries, "max", sd.maxConnRetries, "err", err)
+			// Wait between retries
+			time.Sleep(sd.retryWait)
+		} else {
+			sd.SetConnection(conn)
+			sd.Logger.Debug("SignerDialer: Connection Ready")
+			return nil
+		}
+	}
+
+	sd.Logger.Debug("SignerDialer: Max retries exceeded", "retries", retries, "max", sd.maxConnRetries)
+
+	return ErrNoConnection
+}

privval/signer_endpoint.go

@@ -0,0 +1,156 @@
+package privval
+
+import (
+	"fmt"
+	"net"
+	"sync"
+	"time"
+
+	"github.com/pkg/errors"
+
+	cmn "github.com/tendermint/tendermint/libs/common"
+)
+
+const (
+	defaultTimeoutReadWriteSeconds = 3
+)
+
+type signerEndpoint struct {
+	cmn.BaseService
+
+	connMtx sync.Mutex
+	conn    net.Conn
+
+	timeoutReadWrite time.Duration
+}
+
+// Close closes the underlying net.Conn.
+func (se *signerEndpoint) Close() error {
+	se.DropConnection()
+	return nil
+}
+
+// IsConnected indicates if there is an active connection
+func (se *signerEndpoint) IsConnected() bool {
+	se.connMtx.Lock()
+	defer se.connMtx.Unlock()
+	return se.isConnected()
+}
+
+// TryGetConnection retrieves a connection if it is already available
+func (se *signerEndpoint) GetAvailableConnection(connectionAvailableCh chan net.Conn) bool {
+	se.connMtx.Lock()
+	defer se.connMtx.Unlock()
+
+	// Is there a connection ready?
+	select {
+	case se.conn = <-connectionAvailableCh:
+		return true
+	default:
+	}
+	return false
+}
+
+// TryGetConnection retrieves a connection if it is already available
+func (se *signerEndpoint) WaitConnection(connectionAvailableCh chan net.Conn, maxWait time.Duration) error {
+	se.connMtx.Lock()
+	defer se.connMtx.Unlock()
+
+	select {
+	case se.conn = <-connectionAvailableCh:
+	case <-time.After(maxWait):
+		return ErrConnectionTimeout
+	}
+
+	return nil
+}
+
+// SetConnection replaces the current connection object
+func (se *signerEndpoint) SetConnection(newConnection net.Conn) {
+	se.connMtx.Lock()
+	defer se.connMtx.Unlock()
+	se.conn = newConnection
+}
+
+// IsConnected indicates if there is an active connection
+func (se *signerEndpoint) DropConnection() {
+	se.connMtx.Lock()
+	defer se.connMtx.Unlock()
+	se.dropConnection()
+}
+
+// ReadMessage reads a message from the endpoint
+func (se *signerEndpoint) ReadMessage() (msg SignerMessage, err error) {
+	se.connMtx.Lock()
+	defer se.connMtx.Unlock()
+
+	if !se.isConnected() {
+		return nil, fmt.Errorf("endpoint is not connected")
+	}
+
+	// Reset read deadline
+	deadline := time.Now().Add(se.timeoutReadWrite)
+
+	err = se.conn.SetReadDeadline(deadline)
+	if err != nil {
+		return
+	}
+
+	const maxRemoteSignerMsgSize = 1024 * 10
+	_, err = cdc.UnmarshalBinaryLengthPrefixedReader(se.conn, &msg, maxRemoteSignerMsgSize)
+	if _, ok := err.(timeoutError); ok {
+		if err != nil {
+			err = errors.Wrap(ErrReadTimeout, err.Error())
+		} else {
+			err = errors.Wrap(ErrReadTimeout, "Empty error")
+		}
+		se.Logger.Debug("Dropping [read]", "obj", se)
+		se.dropConnection()
+	}
+
+	return
+}
+
+// WriteMessage writes a message from the endpoint
+func (se *signerEndpoint) WriteMessage(msg SignerMessage) (err error) {
+	se.connMtx.Lock()
+	defer se.connMtx.Unlock()
+
+	if !se.isConnected() {
+		return errors.Wrap(ErrNoConnection, "endpoint is not connected")
+	}
+
+	// Reset read deadline
+	deadline := time.Now().Add(se.timeoutReadWrite)
+	se.Logger.Debug("Write::Error Resetting deadline", "obj", se)
+
+	err = se.conn.SetWriteDeadline(deadline)
+	if err != nil {
+		return
+	}
+
+	_, err = cdc.MarshalBinaryLengthPrefixedWriter(se.conn, msg)
+	if _, ok := err.(timeoutError); ok {
+		if err != nil {
+			err = errors.Wrap(ErrWriteTimeout, err.Error())
+		} else {
+			err = errors.Wrap(ErrWriteTimeout, "Empty error")
+		}
+		se.dropConnection()
+	}
+
+	return
+}
+
+func (se *signerEndpoint) isConnected() bool {
+	return se.conn != nil
+}
+
+func (se *signerEndpoint) dropConnection() {
+	if se.conn != nil {
+		if err := se.conn.Close(); err != nil {
+			se.Logger.Error("signerEndpoint::dropConnection", "err", err)
+		}
+		se.conn = nil
+	}
+}

privval/signer_listener_endpoint.go

@@ -0,0 +1,198 @@
+package privval
+
+import (
+	"fmt"
+	"net"
+	"sync"
+	"time"
+
+	cmn "github.com/tendermint/tendermint/libs/common"
+	"github.com/tendermint/tendermint/libs/log"
+)
+
+// SignerValidatorEndpointOption sets an optional parameter on the SocketVal.
+type SignerValidatorEndpointOption func(*SignerListenerEndpoint)
+
+// SignerListenerEndpoint listens for an external process to dial in
+// and keeps the connection alive by dropping and reconnecting
+type SignerListenerEndpoint struct {
+	signerEndpoint
+
+	listener              net.Listener
+	connectRequestCh      chan struct{}
+	connectionAvailableCh chan net.Conn
+
+	timeoutAccept time.Duration
+	pingTimer     *time.Ticker
+
+	instanceMtx sync.Mutex // Ensures instance public methods access, i.e. SendRequest
+}
+
+// NewSignerListenerEndpoint returns an instance of SignerListenerEndpoint.
+func NewSignerListenerEndpoint(
+	logger log.Logger,
+	listener net.Listener,
+) *SignerListenerEndpoint {
+	sc := &SignerListenerEndpoint{
+		listener:      listener,
+		timeoutAccept: defaultTimeoutAcceptSeconds * time.Second,
+	}
+
+	sc.BaseService = *cmn.NewBaseService(logger, "SignerListenerEndpoint", sc)
+	sc.signerEndpoint.timeoutReadWrite = defaultTimeoutReadWriteSeconds * time.Second
+	return sc
+}
+
+// OnStart implements cmn.Service.
+func (sl *SignerListenerEndpoint) OnStart() error {
+	sl.connectRequestCh = make(chan struct{})
+	sl.connectionAvailableCh = make(chan net.Conn)
+
+	sl.pingTimer = time.NewTicker(defaultPingPeriodMilliseconds * time.Millisecond)
+
+	go sl.serviceLoop()
+	go sl.pingLoop()
+
+	sl.connectRequestCh <- struct{}{}
+
+	return nil
+}
+
+// OnStop implements cmn.Service
+func (sl *SignerListenerEndpoint) OnStop() {
+	sl.instanceMtx.Lock()
+	defer sl.instanceMtx.Unlock()
+	_ = sl.Close()
+
+	// Stop listening
+	if sl.listener != nil {
+		if err := sl.listener.Close(); err != nil {
+			sl.Logger.Error("Closing Listener", "err", err)
+			sl.listener = nil
+		}
+	}
+
+	sl.pingTimer.Stop()
+}
+
+// WaitForConnection waits maxWait for a connection or returns a timeout error
+func (sl *SignerListenerEndpoint) WaitForConnection(maxWait time.Duration) error {
+	sl.instanceMtx.Lock()
+	defer sl.instanceMtx.Unlock()
+	return sl.ensureConnection(maxWait)
+}
+
+// SendRequest ensures there is a connection, sends a request and waits for a response
+func (sl *SignerListenerEndpoint) SendRequest(request SignerMessage) (SignerMessage, error) {
+	sl.instanceMtx.Lock()
+	defer sl.instanceMtx.Unlock()
+
+	err := sl.ensureConnection(sl.timeoutAccept)
+	if err != nil {
+		return nil, err
+	}
+
+	err = sl.WriteMessage(request)
+	if err != nil {
+		return nil, err
+	}
+
+	res, err := sl.ReadMessage()
+	if err != nil {
+		return nil, err
+	}
+
+	return res, nil
+}
+
+func (sl *SignerListenerEndpoint) ensureConnection(maxWait time.Duration) error {
+	if sl.IsConnected() {
+		return nil
+	}
+
+	// Is there a connection ready? then use it
+	if sl.GetAvailableConnection(sl.connectionAvailableCh) {
+		return nil
+	}
+
+	// block until connected or timeout
+	sl.triggerConnect()
+	err := sl.WaitConnection(sl.connectionAvailableCh, maxWait)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (sl *SignerListenerEndpoint) acceptNewConnection() (net.Conn, error) {
+	if !sl.IsRunning() || sl.listener == nil {
+		return nil, fmt.Errorf("endpoint is closing")
+	}
+
+	// wait for a new conn
+	sl.Logger.Info("SignerListener: Listening for new connection")
+	conn, err := sl.listener.Accept()
+	if err != nil {
+		return nil, err
+	}
+
+	return conn, nil
+}
+
+func (sl *SignerListenerEndpoint) triggerConnect() {
+	select {
+	case sl.connectRequestCh <- struct{}{}:
+	default:
+	}
+}
+
+func (sl *SignerListenerEndpoint) triggerReconnect() {
+	sl.DropConnection()
+	sl.triggerConnect()
+}
+
+func (sl *SignerListenerEndpoint) serviceLoop() {
+	for {
+		select {
+		case <-sl.connectRequestCh:
+			{
+				conn, err := sl.acceptNewConnection()
+				if err == nil {
+					sl.Logger.Info("SignerListener: Connected")
+
+					// We have a good connection, wait for someone that needs one otherwise cancellation
+					select {
+					case sl.connectionAvailableCh <- conn:
+					case <-sl.Quit():
+						return
+					}
+				}
+
+				select {
+				case sl.connectRequestCh <- struct{}{}:
+				default:
+				}
+			}
+		case <-sl.Quit():
+			return
+		}
+	}
+}
+
+func (sl *SignerListenerEndpoint) pingLoop() {
+	for {
+		select {
+		case <-sl.pingTimer.C:
+			{
+				_, err := sl.SendRequest(&PingRequest{})
+				if err != nil {
+					sl.Logger.Error("SignerListener: Ping timeout")
+					sl.triggerReconnect()
+				}
+			}
+		case <-sl.Quit():
+			return
+		}
+	}
+}

privval/signer_listener_endpoint_test.go

@@ -0,0 +1,198 @@
+package privval
+
+import (
+	"net"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/tendermint/tendermint/crypto/ed25519"
+	cmn "github.com/tendermint/tendermint/libs/common"
+	"github.com/tendermint/tendermint/libs/log"
+	"github.com/tendermint/tendermint/types"
+)
+
+var (
+	testTimeoutAccept = defaultTimeoutAcceptSeconds * time.Second
+
+	testTimeoutReadWrite    = 100 * time.Millisecond
+	testTimeoutReadWrite2o3 = 60 * time.Millisecond // 2/3 of the other one
+)
+
+type dialerTestCase struct {
+	addr   string
+	dialer SocketDialer
+}
+
+// TestSignerRemoteRetryTCPOnly will test connection retry attempts over TCP. We
+// don't need this for Unix sockets because the OS instantly knows the state of
+// both ends of the socket connection. This basically causes the
+// SignerDialerEndpoint.dialer() call inside SignerDialerEndpoint.acceptNewConnection() to return
+// successfully immediately, putting an instant stop to any retry attempts.
+func TestSignerRemoteRetryTCPOnly(t *testing.T) {
+	var (
+		attemptCh = make(chan int)
+		retries   = 10
+	)
+
+	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	require.NoError(t, err)
+
+	// Continuously Accept connection and close {attempts} times
+	go func(ln net.Listener, attemptCh chan<- int) {
+		attempts := 0
+		for {
+			conn, err := ln.Accept()
+			require.NoError(t, err)
+
+			err = conn.Close()
+			require.NoError(t, err)
+
+			attempts++
+
+			if attempts == retries {
+				attemptCh <- attempts
+				break
+			}
+		}
+	}(ln, attemptCh)
+
+	dialerEndpoint := NewSignerDialerEndpoint(
+		log.TestingLogger(),
+		DialTCPFn(ln.Addr().String(), testTimeoutReadWrite, ed25519.GenPrivKey()),
+	)
+	SignerDialerEndpointTimeoutReadWrite(time.Millisecond)(dialerEndpoint)
+	SignerDialerEndpointConnRetries(retries)(dialerEndpoint)
+
+	chainId := cmn.RandStr(12)
+	mockPV := types.NewMockPV()
+	signerServer := NewSignerServer(dialerEndpoint, chainId, mockPV)
+
+	err = signerServer.Start()
+	require.NoError(t, err)
+	defer signerServer.Stop()
+
+	select {
+	case attempts := <-attemptCh:
+		assert.Equal(t, retries, attempts)
+	case <-time.After(1500 * time.Millisecond):
+		t.Error("expected remote to observe connection attempts")
+	}
+}
+
+func TestRetryConnToRemoteSigner(t *testing.T) {
+	for _, tc := range getDialerTestCases(t) {
+		var (
+			logger           = log.TestingLogger()
+			chainID          = cmn.RandStr(12)
+			mockPV           = types.NewMockPV()
+			endpointIsOpenCh = make(chan struct{})
+			thisConnTimeout  = testTimeoutReadWrite
+			listenerEndpoint = newSignerListenerEndpoint(logger, tc.addr, thisConnTimeout)
+		)
+
+		dialerEndpoint := NewSignerDialerEndpoint(
+			logger,
+			tc.dialer,
+		)
+		SignerDialerEndpointTimeoutReadWrite(testTimeoutReadWrite)(dialerEndpoint)
+		SignerDialerEndpointConnRetries(10)(dialerEndpoint)
+
+		signerServer := NewSignerServer(dialerEndpoint, chainID, mockPV)
+
+		startListenerEndpointAsync(t, listenerEndpoint, endpointIsOpenCh)
+		defer listenerEndpoint.Stop()
+
+		require.NoError(t, signerServer.Start())
+		assert.True(t, signerServer.IsRunning())
+		<-endpointIsOpenCh
+		signerServer.Stop()
+
+		dialerEndpoint2 := NewSignerDialerEndpoint(
+			logger,
+			tc.dialer,
+		)
+		signerServer2 := NewSignerServer(dialerEndpoint2, chainID, mockPV)
+
+		// let some pings pass
+		require.NoError(t, signerServer2.Start())
+		assert.True(t, signerServer2.IsRunning())
+		defer signerServer2.Stop()
+
+		// give the client some time to re-establish the conn to the remote signer
+		// should see sth like this in the logs:
+		//
+		// E[10016-01-10|17:12:46.128] Ping                                         err="remote signer timed out"
+		// I[10016-01-10|17:16:42.447] Re-created connection to remote signer       impl=SocketVal
+		time.Sleep(testTimeoutReadWrite * 2)
+	}
+}
+
+///////////////////////////////////
+
+func newSignerListenerEndpoint(logger log.Logger, addr string, timeoutReadWrite time.Duration) *SignerListenerEndpoint {
+	proto, address := cmn.ProtocolAndAddress(addr)
+
+	ln, err := net.Listen(proto, address)
+	logger.Info("SignerListener: Listening", "proto", proto, "address", address)
+	if err != nil {
+		panic(err)
+	}
+
+	var listener net.Listener
+
+	if proto == "unix" {
+		unixLn := NewUnixListener(ln)
+		UnixListenerTimeoutAccept(testTimeoutAccept)(unixLn)
+		UnixListenerTimeoutReadWrite(timeoutReadWrite)(unixLn)
+		listener = unixLn
+	} else {
+		tcpLn := NewTCPListener(ln, ed25519.GenPrivKey())
+		TCPListenerTimeoutAccept(testTimeoutAccept)(tcpLn)
+		TCPListenerTimeoutReadWrite(timeoutReadWrite)(tcpLn)
+		listener = tcpLn
+	}
+
+	return NewSignerListenerEndpoint(logger, listener)
+}
+
+func startListenerEndpointAsync(t *testing.T, sle *SignerListenerEndpoint, endpointIsOpenCh chan struct{}) {
+	go func(sle *SignerListenerEndpoint) {
+		require.NoError(t, sle.Start())
+		assert.True(t, sle.IsRunning())
+		close(endpointIsOpenCh)
+	}(sle)
+}
+
+func getMockEndpoints(
+	t *testing.T,
+	addr string,
+	socketDialer SocketDialer,
+) (*SignerListenerEndpoint, *SignerDialerEndpoint) {
+
+	var (
+		logger           = log.TestingLogger()
+		endpointIsOpenCh = make(chan struct{})
+
+		dialerEndpoint = NewSignerDialerEndpoint(
+			logger,
+			socketDialer,
+		)
+
+		listenerEndpoint = newSignerListenerEndpoint(logger, addr, testTimeoutReadWrite)
+	)
+
+	SignerDialerEndpointTimeoutReadWrite(testTimeoutReadWrite)(dialerEndpoint)
+	SignerDialerEndpointConnRetries(1e6)(dialerEndpoint)
+
+	startListenerEndpointAsync(t, listenerEndpoint, endpointIsOpenCh)
+
+	require.NoError(t, dialerEndpoint.Start())
+	assert.True(t, dialerEndpoint.IsRunning())
+
+	<-endpointIsOpenCh
+
+	return listenerEndpoint, dialerEndpoint
+}

privval/signer_remote.go

@@ -1,192 +0,0 @@
-package privval
-
-import (
-	"fmt"
-	"io"
-	"net"
-
-	"github.com/pkg/errors"
-
-	"github.com/tendermint/tendermint/crypto"
-	cmn "github.com/tendermint/tendermint/libs/common"
-	"github.com/tendermint/tendermint/types"
-)
-
-// SignerRemote implements PrivValidator.
-// It uses a net.Conn to request signatures from an external process.
-type SignerRemote struct {
-	conn net.Conn
-
-	// memoized
-	consensusPubKey crypto.PubKey
-}
-
-// Check that SignerRemote implements PrivValidator.
-var _ types.PrivValidator = (*SignerRemote)(nil)
-
-// NewSignerRemote returns an instance of SignerRemote.
-func NewSignerRemote(conn net.Conn) (*SignerRemote, error) {
-
-	// retrieve and memoize the consensus public key once.
-	pubKey, err := getPubKey(conn)
-	if err != nil {
-		return nil, cmn.ErrorWrap(err, "error while retrieving public key for remote signer")
-	}
-	return &SignerRemote{
-		conn:            conn,
-		consensusPubKey: pubKey,
-	}, nil
-}
-
-// Close calls Close on the underlying net.Conn.
-func (sc *SignerRemote) Close() error {
-	return sc.conn.Close()
-}
-
-// GetPubKey implements PrivValidator.
-func (sc *SignerRemote) GetPubKey() crypto.PubKey {
-	return sc.consensusPubKey
-}
-
-// not thread-safe (only called on startup).
-func getPubKey(conn net.Conn) (crypto.PubKey, error) {
-	err := writeMsg(conn, &PubKeyRequest{})
-	if err != nil {
-		return nil, err
-	}
-
-	res, err := readMsg(conn)
-	if err != nil {
-		return nil, err
-	}
-
-	pubKeyResp, ok := res.(*PubKeyResponse)
-	if !ok {
-		return nil, errors.Wrap(ErrUnexpectedResponse, "response is not PubKeyResponse")
-	}
-
-	if pubKeyResp.Error != nil {
-		return nil, errors.Wrap(pubKeyResp.Error, "failed to get private validator's public key")
-	}
-
-	return pubKeyResp.PubKey, nil
-}
-
-// SignVote implements PrivValidator.
-func (sc *SignerRemote) SignVote(chainID string, vote *types.Vote) error {
-	err := writeMsg(sc.conn, &SignVoteRequest{Vote: vote})
-	if err != nil {
-		return err
-	}
-
-	res, err := readMsg(sc.conn)
-	if err != nil {
-		return err
-	}
-
-	resp, ok := res.(*SignedVoteResponse)
-	if !ok {
-		return ErrUnexpectedResponse
-	}
-	if resp.Error != nil {
-		return resp.Error
-	}
-	*vote = *resp.Vote
-
-	return nil
-}
-
-// SignProposal implements PrivValidator.
-func (sc *SignerRemote) SignProposal(chainID string, proposal *types.Proposal) error {
-	err := writeMsg(sc.conn, &SignProposalRequest{Proposal: proposal})
-	if err != nil {
-		return err
-	}
-
-	res, err := readMsg(sc.conn)
-	if err != nil {
-		return err
-	}
-	resp, ok := res.(*SignedProposalResponse)
-	if !ok {
-		return ErrUnexpectedResponse
-	}
-	if resp.Error != nil {
-		return resp.Error
-	}
-	*proposal = *resp.Proposal
-
-	return nil
-}
-
-// Ping is used to check connection health.
-func (sc *SignerRemote) Ping() error {
-	err := writeMsg(sc.conn, &PingRequest{})
-	if err != nil {
-		return err
-	}
-
-	res, err := readMsg(sc.conn)
-	if err != nil {
-		return err
-	}
-	_, ok := res.(*PingResponse)
-	if !ok {
-		return ErrUnexpectedResponse
-	}
-
-	return nil
-}
-
-func readMsg(r io.Reader) (msg RemoteSignerMsg, err error) {
-	const maxRemoteSignerMsgSize = 1024 * 10
-	_, err = cdc.UnmarshalBinaryLengthPrefixedReader(r, &msg, maxRemoteSignerMsgSize)
-	if _, ok := err.(timeoutError); ok {
-		err = cmn.ErrorWrap(ErrConnTimeout, err.Error())
-	}
-	return
-}
-
-func writeMsg(w io.Writer, msg interface{}) (err error) {
-	_, err = cdc.MarshalBinaryLengthPrefixedWriter(w, msg)
-	if _, ok := err.(timeoutError); ok {
-		err = cmn.ErrorWrap(ErrConnTimeout, err.Error())
-	}
-	return
-}
-
-func handleRequest(req RemoteSignerMsg, chainID string, privVal types.PrivValidator) (RemoteSignerMsg, error) {
-	var res RemoteSignerMsg
-	var err error
-
-	switch r := req.(type) {
-	case *PubKeyRequest:
-		var p crypto.PubKey
-		p = privVal.GetPubKey()
-		res = &PubKeyResponse{p, nil}
-
-	case *SignVoteRequest:
-		err = privVal.SignVote(chainID, r.Vote)
-		if err != nil {
-			res = &SignedVoteResponse{nil, &RemoteSignerError{0, err.Error()}}
-		} else {
-			res = &SignedVoteResponse{r.Vote, nil}
-		}
-
-	case *SignProposalRequest:
-		err = privVal.SignProposal(chainID, r.Proposal)
-		if err != nil {
-			res = &SignedProposalResponse{nil, &RemoteSignerError{0, err.Error()}}
-		} else {
-			res = &SignedProposalResponse{r.Proposal, nil}
-		}
-
-	case *PingRequest:
-		res = &PingResponse{}
-
-	default:
-		err = fmt.Errorf("unknown msg: %v", r)
-	}
-
-	return res, err
-}

privval/signer_remote_test.go

@@ -1,68 +0,0 @@
-package privval
-
-import (
-	"net"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"github.com/tendermint/tendermint/crypto/ed25519"
-	cmn "github.com/tendermint/tendermint/libs/common"
-	"github.com/tendermint/tendermint/libs/log"
-	"github.com/tendermint/tendermint/types"
-)
-
-// TestSignerRemoteRetryTCPOnly will test connection retry attempts over TCP. We
-// don't need this for Unix sockets because the OS instantly knows the state of
-// both ends of the socket connection. This basically causes the
-// SignerServiceEndpoint.dialer() call inside SignerServiceEndpoint.connect() to return
-// successfully immediately, putting an instant stop to any retry attempts.
-func TestSignerRemoteRetryTCPOnly(t *testing.T) {
-	var (
-		attemptCh = make(chan int)
-		retries   = 2
-	)
-
-	ln, err := net.Listen("tcp", "127.0.0.1:0")
-	require.NoError(t, err)
-
-	go func(ln net.Listener, attemptCh chan<- int) {
-		attempts := 0
-
-		for {
-			conn, err := ln.Accept()
-			require.NoError(t, err)
-
-			err = conn.Close()
-			require.NoError(t, err)
-
-			attempts++
-
-			if attempts == retries {
-				attemptCh <- attempts
-				break
-			}
-		}
-	}(ln, attemptCh)
-
-	serviceEndpoint := NewSignerServiceEndpoint(
-		log.TestingLogger(),
-		cmn.RandStr(12),
-		types.NewMockPV(),
-		DialTCPFn(ln.Addr().String(), testTimeoutReadWrite, ed25519.GenPrivKey()),
-	)
-	defer serviceEndpoint.Stop()
-
-	SignerServiceEndpointTimeoutReadWrite(time.Millisecond)(serviceEndpoint)
-	SignerServiceEndpointConnRetries(retries)(serviceEndpoint)
-
-	assert.Equal(t, serviceEndpoint.Start(), ErrDialRetryMax)
-
-	select {
-	case attempts := <-attemptCh:
-		assert.Equal(t, retries, attempts)
-	case <-time.After(100 * time.Millisecond):
-		t.Error("expected remote to observe connection attempts")
-	}
-}

privval/signer_requestHandler.go

@@ -0,0 +1,44 @@
+package privval
+
+import (
+	"fmt"
+
+	"github.com/tendermint/tendermint/crypto"
+	"github.com/tendermint/tendermint/types"
+)
+
+func DefaultValidationRequestHandler(privVal types.PrivValidator, req SignerMessage, chainID string) (SignerMessage, error) {
+	var res SignerMessage
+	var err error
+
+	switch r := req.(type) {
+	case *PubKeyRequest:
+		var p crypto.PubKey
+		p = privVal.GetPubKey()
+		res = &PubKeyResponse{p, nil}
+
+	case *SignVoteRequest:
+		err = privVal.SignVote(chainID, r.Vote)
+		if err != nil {
+			res = &SignedVoteResponse{nil, &RemoteSignerError{0, err.Error()}}
+		} else {
+			res = &SignedVoteResponse{r.Vote, nil}
+		}
+
+	case *SignProposalRequest:
+		err = privVal.SignProposal(chainID, r.Proposal)
+		if err != nil {
+			res = &SignedProposalResponse{nil, &RemoteSignerError{0, err.Error()}}
+		} else {
+			res = &SignedProposalResponse{r.Proposal, nil}
+		}
+
+	case *PingRequest:
+		err, res = nil, &PingResponse{}
+
+	default:
+		err = fmt.Errorf("unknown msg: %v", r)
+	}
+
+	return res, err
+}

privval/signer_server.go

@@ -0,0 +1,107 @@
+package privval
+
+import (
+	"io"
+	"sync"
+
+	cmn "github.com/tendermint/tendermint/libs/common"
+	"github.com/tendermint/tendermint/types"
+)
+
+// ValidationRequestHandlerFunc handles different remoteSigner requests
+type ValidationRequestHandlerFunc func(
+	privVal types.PrivValidator,
+	requestMessage SignerMessage,
+	chainID string) (SignerMessage, error)
+
+type SignerServer struct {
+	cmn.BaseService
+
+	endpoint *SignerDialerEndpoint
+	chainID  string
+	privVal  types.PrivValidator
+
+	handlerMtx               sync.Mutex
+	validationRequestHandler ValidationRequestHandlerFunc
+}
+
+func NewSignerServer(endpoint *SignerDialerEndpoint, chainID string, privVal types.PrivValidator) *SignerServer {
+	ss := &SignerServer{
+		endpoint:                 endpoint,
+		chainID:                  chainID,
+		privVal:                  privVal,
+		validationRequestHandler: DefaultValidationRequestHandler,
+	}
+
+	ss.BaseService = *cmn.NewBaseService(endpoint.Logger, "SignerServer", ss)
+
+	return ss
+}
+
+// OnStart implements cmn.Service.
+func (ss *SignerServer) OnStart() error {
+	go ss.serviceLoop()
+	return nil
+}
+
+// OnStop implements cmn.Service.
+func (ss *SignerServer) OnStop() {
+	ss.endpoint.Logger.Debug("SignerServer: OnStop calling Close")
+	_ = ss.endpoint.Close()
+}
+
+// SetRequestHandler override the default function that is used to service requests
+func (ss *SignerServer) SetRequestHandler(validationRequestHandler ValidationRequestHandlerFunc) {
+	ss.handlerMtx.Lock()
+	defer ss.handlerMtx.Unlock()
+	ss.validationRequestHandler = validationRequestHandler
+}
+
+func (ss *SignerServer) servicePendingRequest() {
+	if !ss.IsRunning() {
+		return // Ignore error from closing.
+	}
+
+	req, err := ss.endpoint.ReadMessage()
+	if err != nil {
+		if err != io.EOF {
+			ss.Logger.Error("SignerServer: HandleMessage", "err", err)
+		}
+		return
+	}
+
+	var res SignerMessage
+	{
+		// limit the scope of the lock
+		ss.handlerMtx.Lock()
+		defer ss.handlerMtx.Unlock()
+		res, err = ss.validationRequestHandler(ss.privVal, req, ss.chainID)
+		if err != nil {
+			// only log the error; we'll reply with an error in res
+			ss.Logger.Error("SignerServer: handleMessage", "err", err)
+		}
+	}
+
+	if res != nil {
+		err = ss.endpoint.WriteMessage(res)
+		if err != nil {
+			ss.Logger.Error("SignerServer: writeMessage", "err", err)
+		}
+	}
+}
+
+func (ss *SignerServer) serviceLoop() {
+	for {
+		select {
+		default:
+			err := ss.endpoint.ensureConnection()
+			if err != nil {
+				return
+			}
+			ss.servicePendingRequest()
+
+		case <-ss.Quit():
+			return
+		}
+	}
+}

privval/signer_service_endpoint.go

@@ -1,139 +0,0 @@
-package privval
-
-import (
-	"io"
-	"net"
-	"time"
-
-	cmn "github.com/tendermint/tendermint/libs/common"
-	"github.com/tendermint/tendermint/libs/log"
-	"github.com/tendermint/tendermint/types"
-)
-
-// SignerServiceEndpointOption sets an optional parameter on the SignerServiceEndpoint.
-type SignerServiceEndpointOption func(*SignerServiceEndpoint)
-
-// SignerServiceEndpointTimeoutReadWrite sets the read and write timeout for connections
-// from external signing processes.
-func SignerServiceEndpointTimeoutReadWrite(timeout time.Duration) SignerServiceEndpointOption {
-	return func(ss *SignerServiceEndpoint) { ss.timeoutReadWrite = timeout }
-}
-
-// SignerServiceEndpointConnRetries sets the amount of attempted retries to connect.
-func SignerServiceEndpointConnRetries(retries int) SignerServiceEndpointOption {
-	return func(ss *SignerServiceEndpoint) { ss.connRetries = retries }
-}
-
-// SignerServiceEndpoint dials using its dialer and responds to any
-// signature requests using its privVal.
-type SignerServiceEndpoint struct {
-	cmn.BaseService
-
-	chainID          string
-	timeoutReadWrite time.Duration
-	connRetries      int
-	privVal          types.PrivValidator
-
-	dialer SocketDialer
-	conn   net.Conn
-}
-
-// NewSignerServiceEndpoint returns a SignerServiceEndpoint that will dial using the given
-// dialer and respond to any signature requests over the connection
-// using the given privVal.
-func NewSignerServiceEndpoint(
-	logger log.Logger,
-	chainID string,
-	privVal types.PrivValidator,
-	dialer SocketDialer,
-) *SignerServiceEndpoint {
-	se := &SignerServiceEndpoint{
-		chainID:          chainID,
-		timeoutReadWrite: time.Second * defaultTimeoutReadWriteSeconds,
-		connRetries:      defaultMaxDialRetries,
-		privVal:          privVal,
-		dialer:           dialer,
-	}
-
-	se.BaseService = *cmn.NewBaseService(logger, "SignerServiceEndpoint", se)
-	return se
-}
-
-// OnStart implements cmn.Service.
-func (se *SignerServiceEndpoint) OnStart() error {
-	conn, err := se.connect()
-	if err != nil {
-		se.Logger.Error("OnStart", "err", err)
-		return err
-	}
-
-	se.conn = conn
-	go se.handleConnection(conn)
-
-	return nil
-}
-
-// OnStop implements cmn.Service.
-func (se *SignerServiceEndpoint) OnStop() {
-	if se.conn == nil {
-		return
-	}
-
-	if err := se.conn.Close(); err != nil {
-		se.Logger.Error("OnStop", "err", cmn.ErrorWrap(err, "closing listener failed"))
-	}
-}
-
-func (se *SignerServiceEndpoint) connect() (net.Conn, error) {
-	for retries := 0; retries < se.connRetries; retries++ {
-		// Don't sleep if it is the first retry.
-		if retries > 0 {
-			time.Sleep(se.timeoutReadWrite)
-		}
-
-		conn, err := se.dialer()
-		if err == nil {
-			return conn, nil
-		}
-
-		se.Logger.Error("dialing", "err", err)
-	}
-
-	return nil, ErrDialRetryMax
-}
-
-func (se *SignerServiceEndpoint) handleConnection(conn net.Conn) {
-	for {
-		if !se.IsRunning() {
-			return // Ignore error from listener closing.
-		}
-
-		// Reset the connection deadline
-		deadline := time.Now().Add(se.timeoutReadWrite)
-		err := conn.SetDeadline(deadline)
-		if err != nil {
-			return
-		}
-
-		req, err := readMsg(conn)
-		if err != nil {
-			if err != io.EOF {
-				se.Logger.Error("handleConnection readMsg", "err", err)
-			}
-			return
-		}
-
-		res, err := handleRequest(req, se.chainID, se.privVal)
-
-		if err != nil {
-			// only log the error; we'll reply with an error in res
-			se.Logger.Error("handleConnection handleRequest", "err", err)
-		}
-
-		err = writeMsg(conn, res)
-		if err != nil {
-			se.Logger.Error("handleConnection writeMsg", "err", err)
-			return
-		}
-	}
-}

privval/signer_validator_endpoint.go

@@ -1,230 +0,0 @@
-package privval
-
-import (
-	"fmt"
-	"net"
-	"sync"
-	"time"
-
-	"github.com/tendermint/tendermint/crypto"
-	cmn "github.com/tendermint/tendermint/libs/common"
-	"github.com/tendermint/tendermint/libs/log"
-	"github.com/tendermint/tendermint/types"
-)
-
-const (
-	defaultHeartbeatSeconds = 2
-	defaultMaxDialRetries   = 10
-)
-
-var (
-	heartbeatPeriod = time.Second * defaultHeartbeatSeconds
-)
-
-// SignerValidatorEndpointOption sets an optional parameter on the SocketVal.
-type SignerValidatorEndpointOption func(*SignerValidatorEndpoint)
-
-// SignerValidatorEndpointSetHeartbeat sets the period on which to check the liveness of the
-// connected Signer connections.
-func SignerValidatorEndpointSetHeartbeat(period time.Duration) SignerValidatorEndpointOption {
-	return func(sc *SignerValidatorEndpoint) { sc.heartbeatPeriod = period }
-}
-
-// SocketVal implements PrivValidator.
-// It listens for an external process to dial in and uses
-// the socket to request signatures.
-type SignerValidatorEndpoint struct {
-	cmn.BaseService
-
-	listener net.Listener
-
-	// ping
-	cancelPingCh    chan struct{}
-	pingTicker      *time.Ticker
-	heartbeatPeriod time.Duration
-
-	// signer is mutable since it can be reset if the connection fails.
-	// failures are detected by a background ping routine.
-	// All messages are request/response, so we hold the mutex
-	// so only one request/response pair can happen at a time.
-	// Methods on the underlying net.Conn itself are already goroutine safe.
-	mtx sync.Mutex
-
-	// TODO: Signer should encapsulate and hide the endpoint completely. Invert the relation
-	signer *SignerRemote
-}
-
-// Check that SignerValidatorEndpoint implements PrivValidator.
-var _ types.PrivValidator = (*SignerValidatorEndpoint)(nil)
-
-// NewSignerValidatorEndpoint returns an instance of SignerValidatorEndpoint.
-func NewSignerValidatorEndpoint(logger log.Logger, listener net.Listener) *SignerValidatorEndpoint {
-	sc := &SignerValidatorEndpoint{
-		listener:        listener,
-		heartbeatPeriod: heartbeatPeriod,
-	}
-
-	sc.BaseService = *cmn.NewBaseService(logger, "SignerValidatorEndpoint", sc)
-
-	return sc
-}
-
-//--------------------------------------------------------
-// Implement PrivValidator
-
-// GetPubKey implements PrivValidator.
-func (ve *SignerValidatorEndpoint) GetPubKey() crypto.PubKey {
-	ve.mtx.Lock()
-	defer ve.mtx.Unlock()
-	return ve.signer.GetPubKey()
-}
-
-// SignVote implements PrivValidator.
-func (ve *SignerValidatorEndpoint) SignVote(chainID string, vote *types.Vote) error {
-	ve.mtx.Lock()
-	defer ve.mtx.Unlock()
-	return ve.signer.SignVote(chainID, vote)
-}
-
-// SignProposal implements PrivValidator.
-func (ve *SignerValidatorEndpoint) SignProposal(chainID string, proposal *types.Proposal) error {
-	ve.mtx.Lock()
-	defer ve.mtx.Unlock()
-	return ve.signer.SignProposal(chainID, proposal)
-}
-
-//--------------------------------------------------------
-// More thread safe methods proxied to the signer
-
-// Ping is used to check connection health.
-func (ve *SignerValidatorEndpoint) Ping() error {
-	ve.mtx.Lock()
-	defer ve.mtx.Unlock()
-	return ve.signer.Ping()
-}
-
-// Close closes the underlying net.Conn.
-func (ve *SignerValidatorEndpoint) Close() {
-	ve.mtx.Lock()
-	defer ve.mtx.Unlock()
-	if ve.signer != nil {
-		if err := ve.signer.Close(); err != nil {
-			ve.Logger.Error("OnStop", "err", err)
-		}
-	}
-
-	if ve.listener != nil {
-		if err := ve.listener.Close(); err != nil {
-			ve.Logger.Error("OnStop", "err", err)
-		}
-	}
-}
-
-//--------------------------------------------------------
-// Service start and stop
-
-// OnStart implements cmn.Service.
-func (ve *SignerValidatorEndpoint) OnStart() error {
-	if closed, err := ve.reset(); err != nil {
-		ve.Logger.Error("OnStart", "err", err)
-		return err
-	} else if closed {
-		return fmt.Errorf("listener is closed")
-	}
-
-	// Start a routine to keep the connection alive
-	ve.cancelPingCh = make(chan struct{}, 1)
-	ve.pingTicker = time.NewTicker(ve.heartbeatPeriod)
-	go func() {
-		for {
-			select {
-			case <-ve.pingTicker.C:
-				err := ve.Ping()
-				if err != nil {
-					ve.Logger.Error("Ping", "err", err)
-					if err == ErrUnexpectedResponse {
-						return
-					}
-
-					closed, err := ve.reset()
-					if err != nil {
-						ve.Logger.Error("Reconnecting to remote signer failed", "err", err)
-						continue
-					}
-					if closed {
-						ve.Logger.Info("listener is closing")
-						return
-					}
-
-					ve.Logger.Info("Re-created connection to remote signer", "impl", ve)
-				}
-			case <-ve.cancelPingCh:
-				ve.pingTicker.Stop()
-				return
-			}
-		}
-	}()
-
-	return nil
-}
-
-// OnStop implements cmn.Service.
-func (ve *SignerValidatorEndpoint) OnStop() {
-	if ve.cancelPingCh != nil {
-		close(ve.cancelPingCh)
-	}
-	ve.Close()
-}
-
-//--------------------------------------------------------
-// Connection and signer management
-
-// waits to accept and sets a new connection.
-// connection is closed in OnStop.
-// returns true if the listener is closed
-// (ie. it returns a nil conn).
-func (ve *SignerValidatorEndpoint) reset() (closed bool, err error) {
-	ve.mtx.Lock()
-	defer ve.mtx.Unlock()
-
-	// first check if the conn already exists and close it.
-	if ve.signer != nil {
-		if tmpErr := ve.signer.Close(); tmpErr != nil {
-			ve.Logger.Error("error closing socket val connection during reset", "err", tmpErr)
-		}
-	}
-
-	// wait for a new conn
-	conn, err := ve.acceptConnection()
-	if err != nil {
-		return false, err
-	}
-
-	// listener is closed
-	if conn == nil {
-		return true, nil
-	}
-
-	ve.signer, err = NewSignerRemote(conn)
-	if err != nil {
-		// failed to fetch the pubkey. close out the connection.
-		if tmpErr := conn.Close(); tmpErr != nil {
-			ve.Logger.Error("error closing connection", "err", tmpErr)
-		}
-		return false, err
-	}
-	return false, nil
-}
-
-// Attempt to accept a connection.
-// Times out after the listener's timeoutAccept
-func (ve *SignerValidatorEndpoint) acceptConnection() (net.Conn, error) {
-	conn, err := ve.listener.Accept()
-	if err != nil {
-		if !ve.IsRunning() {
-			return nil, nil // Ignore error from listener closing.
-		}
-		return nil, err
-	}
-	return conn, nil
-}

privval/signer_validator_endpoint_test.go

@@ -1,506 +0,0 @@
-package privval
-
-import (
-	"fmt"
-	"net"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/tendermint/tendermint/crypto/ed25519"
-	cmn "github.com/tendermint/tendermint/libs/common"
-	"github.com/tendermint/tendermint/libs/log"
-
-	"github.com/tendermint/tendermint/types"
-)
-
-var (
-	testTimeoutAccept = defaultTimeoutAcceptSeconds * time.Second
-
-	testTimeoutReadWrite    = 100 * time.Millisecond
-	testTimeoutReadWrite2o3 = 66 * time.Millisecond // 2/3 of the other one
-
-	testTimeoutHeartbeat    = 10 * time.Millisecond
-	testTimeoutHeartbeat3o2 = 6 * time.Millisecond // 3/2 of the other one
-)
-
-type socketTestCase struct {
-	addr   string
-	dialer SocketDialer
-}
-
-func socketTestCases(t *testing.T) []socketTestCase {
-	tcpAddr := fmt.Sprintf("tcp://%s", testFreeTCPAddr(t))
-	unixFilePath, err := testUnixAddr()
-	require.NoError(t, err)
-	unixAddr := fmt.Sprintf("unix://%s", unixFilePath)
-	return []socketTestCase{
-		{
-			addr:   tcpAddr,
-			dialer: DialTCPFn(tcpAddr, testTimeoutReadWrite, ed25519.GenPrivKey()),
-		},
-		{
-			addr:   unixAddr,
-			dialer: DialUnixFn(unixFilePath),
-		},
-	}
-}
-
-func TestSocketPVAddress(t *testing.T) {
-	for _, tc := range socketTestCases(t) {
-		// Execute the test within a closure to ensure the deferred statements
-		// are called between each for loop iteration, for isolated test cases.
-		func() {
-			var (
-				chainID                            = cmn.RandStr(12)
-				validatorEndpoint, serviceEndpoint = testSetupSocketPair(t, chainID, types.NewMockPV(), tc.addr, tc.dialer)
-			)
-			defer validatorEndpoint.Stop()
-			defer serviceEndpoint.Stop()
-
-			serviceAddr := serviceEndpoint.privVal.GetPubKey().Address()
-			validatorAddr := validatorEndpoint.GetPubKey().Address()
-
-			assert.Equal(t, serviceAddr, validatorAddr)
-		}()
-	}
-}
-
-func TestSocketPVPubKey(t *testing.T) {
-	for _, tc := range socketTestCases(t) {
-		func() {
-			var (
-				chainID                            = cmn.RandStr(12)
-				validatorEndpoint, serviceEndpoint = testSetupSocketPair(
-					t,
-					chainID,
-					types.NewMockPV(),
-					tc.addr,
-					tc.dialer)
-			)
-			defer validatorEndpoint.Stop()
-			defer serviceEndpoint.Stop()
-
-			clientKey := validatorEndpoint.GetPubKey()
-			privvalPubKey := serviceEndpoint.privVal.GetPubKey()
-
-			assert.Equal(t, privvalPubKey, clientKey)
-		}()
-	}
-}
-
-func TestSocketPVProposal(t *testing.T) {
-	for _, tc := range socketTestCases(t) {
-		func() {
-			var (
-				chainID                            = cmn.RandStr(12)
-				validatorEndpoint, serviceEndpoint = testSetupSocketPair(
-					t,
-					chainID,
-					types.NewMockPV(),
-					tc.addr,
-					tc.dialer)
-
-				ts             = time.Now()
-				privProposal   = &types.Proposal{Timestamp: ts}
-				clientProposal = &types.Proposal{Timestamp: ts}
-			)
-			defer validatorEndpoint.Stop()
-			defer serviceEndpoint.Stop()
-
-			require.NoError(t, serviceEndpoint.privVal.SignProposal(chainID, privProposal))
-			require.NoError(t, validatorEndpoint.SignProposal(chainID, clientProposal))
-
-			assert.Equal(t, privProposal.Signature, clientProposal.Signature)
-		}()
-	}
-}
-
-func TestSocketPVVote(t *testing.T) {
-	for _, tc := range socketTestCases(t) {
-		func() {
-			var (
-				chainID                            = cmn.RandStr(12)
-				validatorEndpoint, serviceEndpoint = testSetupSocketPair(
-					t,
-					chainID,
-					types.NewMockPV(),
-					tc.addr,
-					tc.dialer)
-
-				ts    = time.Now()
-				vType = types.PrecommitType
-				want  = &types.Vote{Timestamp: ts, Type: vType}
-				have  = &types.Vote{Timestamp: ts, Type: vType}
-			)
-			defer validatorEndpoint.Stop()
-			defer serviceEndpoint.Stop()
-
-			require.NoError(t, serviceEndpoint.privVal.SignVote(chainID, want))
-			require.NoError(t, validatorEndpoint.SignVote(chainID, have))
-			assert.Equal(t, want.Signature, have.Signature)
-		}()
-	}
-}
-
-func TestSocketPVVoteResetDeadline(t *testing.T) {
-	for _, tc := range socketTestCases(t) {
-		func() {
-			var (
-				chainID                            = cmn.RandStr(12)
-				validatorEndpoint, serviceEndpoint = testSetupSocketPair(
-					t,
-					chainID,
-					types.NewMockPV(),
-					tc.addr,
-					tc.dialer)
-
-				ts    = time.Now()
-				vType = types.PrecommitType
-				want  = &types.Vote{Timestamp: ts, Type: vType}
-				have  = &types.Vote{Timestamp: ts, Type: vType}
-			)
-			defer validatorEndpoint.Stop()
-			defer serviceEndpoint.Stop()
-
-			time.Sleep(testTimeoutReadWrite2o3)
-
-			require.NoError(t, serviceEndpoint.privVal.SignVote(chainID, want))
-			require.NoError(t, validatorEndpoint.SignVote(chainID, have))
-			assert.Equal(t, want.Signature, have.Signature)
-
-			// This would exceed the deadline if it was not extended by the previous message
-			time.Sleep(testTimeoutReadWrite2o3)
-
-			require.NoError(t, serviceEndpoint.privVal.SignVote(chainID, want))
-			require.NoError(t, validatorEndpoint.SignVote(chainID, have))
-			assert.Equal(t, want.Signature, have.Signature)
-		}()
-	}
-}
-
-func TestSocketPVVoteKeepalive(t *testing.T) {
-	for _, tc := range socketTestCases(t) {
-		func() {
-			var (
-				chainID                            = cmn.RandStr(12)
-				validatorEndpoint, serviceEndpoint = testSetupSocketPair(
-					t,
-					chainID,
-					types.NewMockPV(),
-					tc.addr,
-					tc.dialer)
-
-				ts    = time.Now()
-				vType = types.PrecommitType
-				want  = &types.Vote{Timestamp: ts, Type: vType}
-				have  = &types.Vote{Timestamp: ts, Type: vType}
-			)
-			defer validatorEndpoint.Stop()
-			defer serviceEndpoint.Stop()
-
-			time.Sleep(testTimeoutReadWrite * 2)
-
-			require.NoError(t, serviceEndpoint.privVal.SignVote(chainID, want))
-			require.NoError(t, validatorEndpoint.SignVote(chainID, have))
-			assert.Equal(t, want.Signature, have.Signature)
-		}()
-	}
-}
-
-func TestSocketPVDeadline(t *testing.T) {
-	for _, tc := range socketTestCases(t) {
-		func() {
-			var (
-				listenc           = make(chan struct{})
-				thisConnTimeout   = 100 * time.Millisecond
-				validatorEndpoint = newSignerValidatorEndpoint(log.TestingLogger(), tc.addr, thisConnTimeout)
-			)
-
-			go func(sc *SignerValidatorEndpoint) {
-				defer close(listenc)
-
-				// Note: the TCP connection times out at the accept() phase,
-				// whereas the Unix domain sockets connection times out while
-				// attempting to fetch the remote signer's public key.
-				assert.True(t, IsConnTimeout(sc.Start()))
-
-				assert.False(t, sc.IsRunning())
-			}(validatorEndpoint)
-
-			for {
-				_, err := cmn.Connect(tc.addr)
-				if err == nil {
-					break
-				}
-			}
-
-			<-listenc
-		}()
-	}
-}
-
-func TestRemoteSignVoteErrors(t *testing.T) {
-	for _, tc := range socketTestCases(t) {
-		func() {
-			var (
-				chainID                            = cmn.RandStr(12)
-				validatorEndpoint, serviceEndpoint = testSetupSocketPair(
-					t,
-					chainID,
-					types.NewErroringMockPV(),
-					tc.addr,
-					tc.dialer)
-
-				ts    = time.Now()
-				vType = types.PrecommitType
-				vote  = &types.Vote{Timestamp: ts, Type: vType}
-			)
-			defer validatorEndpoint.Stop()
-			defer serviceEndpoint.Stop()
-
-			err := validatorEndpoint.SignVote("", vote)
-			require.Equal(t, err.(*RemoteSignerError).Description, types.ErroringMockPVErr.Error())
-
-			err = serviceEndpoint.privVal.SignVote(chainID, vote)
-			require.Error(t, err)
-			err = validatorEndpoint.SignVote(chainID, vote)
-			require.Error(t, err)
-		}()
-	}
-}
-
-func TestRemoteSignProposalErrors(t *testing.T) {
-	for _, tc := range socketTestCases(t) {
-		func() {
-			var (
-				chainID                            = cmn.RandStr(12)
-				validatorEndpoint, serviceEndpoint = testSetupSocketPair(
-					t,
-					chainID,
-					types.NewErroringMockPV(),
-					tc.addr,
-					tc.dialer)
-
-				ts       = time.Now()
-				proposal = &types.Proposal{Timestamp: ts}
-			)
-			defer validatorEndpoint.Stop()
-			defer serviceEndpoint.Stop()
-
-			err := validatorEndpoint.SignProposal("", proposal)
-			require.Equal(t, err.(*RemoteSignerError).Description, types.ErroringMockPVErr.Error())
-
-			err = serviceEndpoint.privVal.SignProposal(chainID, proposal)
-			require.Error(t, err)
-
-			err = validatorEndpoint.SignProposal(chainID, proposal)
-			require.Error(t, err)
-		}()
-	}
-}
-
-func TestErrUnexpectedResponse(t *testing.T) {
-	for _, tc := range socketTestCases(t) {
-		func() {
-			var (
-				logger  = log.TestingLogger()
-				chainID = cmn.RandStr(12)
-				readyCh = make(chan struct{})
-				errCh   = make(chan error, 1)
-
-				serviceEndpoint = NewSignerServiceEndpoint(
-					logger,
-					chainID,
-					types.NewMockPV(),
-					tc.dialer,
-				)
-
-				validatorEndpoint = newSignerValidatorEndpoint(
-					logger,
-					tc.addr,
-					testTimeoutReadWrite)
-			)
-
-			testStartEndpoint(t, readyCh, validatorEndpoint)
-			defer validatorEndpoint.Stop()
-			SignerServiceEndpointTimeoutReadWrite(time.Millisecond)(serviceEndpoint)
-			SignerServiceEndpointConnRetries(100)(serviceEndpoint)
-			// we do not want to Start() the remote signer here and instead use the connection to
-			// reply with intentionally wrong replies below:
-			rsConn, err := serviceEndpoint.connect()
-			require.NoError(t, err)
-			require.NotNil(t, rsConn)
-			defer rsConn.Close()
-
-			// send over public key to get the remote signer running:
-			go testReadWriteResponse(t, &PubKeyResponse{}, rsConn)
-			<-readyCh
-
-			// Proposal:
-			go func(errc chan error) {
-				errc <- validatorEndpoint.SignProposal(chainID, &types.Proposal{})
-			}(errCh)
-
-			// read request and write wrong response:
-			go testReadWriteResponse(t, &SignedVoteResponse{}, rsConn)
-			err = <-errCh
-			require.Error(t, err)
-			require.Equal(t, err, ErrUnexpectedResponse)
-
-			// Vote:
-			go func(errc chan error) {
-				errc <- validatorEndpoint.SignVote(chainID, &types.Vote{})
-			}(errCh)
-			// read request and write wrong response:
-			go testReadWriteResponse(t, &SignedProposalResponse{}, rsConn)
-			err = <-errCh
-			require.Error(t, err)
-			require.Equal(t, err, ErrUnexpectedResponse)
-		}()
-	}
-}
-
-func TestRetryConnToRemoteSigner(t *testing.T) {
-	for _, tc := range socketTestCases(t) {
-		func() {
-			var (
-				logger  = log.TestingLogger()
-				chainID = cmn.RandStr(12)
-				readyCh = make(chan struct{})
-
-				serviceEndpoint = NewSignerServiceEndpoint(
-					logger,
-					chainID,
-					types.NewMockPV(),
-					tc.dialer,
-				)
-				thisConnTimeout   = testTimeoutReadWrite
-				validatorEndpoint = newSignerValidatorEndpoint(logger, tc.addr, thisConnTimeout)
-			)
-			// Ping every:
-			SignerValidatorEndpointSetHeartbeat(testTimeoutHeartbeat)(validatorEndpoint)
-
-			SignerServiceEndpointTimeoutReadWrite(testTimeoutReadWrite)(serviceEndpoint)
-			SignerServiceEndpointConnRetries(10)(serviceEndpoint)
-
-			testStartEndpoint(t, readyCh, validatorEndpoint)
-			defer validatorEndpoint.Stop()
-			require.NoError(t, serviceEndpoint.Start())
-			assert.True(t, serviceEndpoint.IsRunning())
-
-			<-readyCh
-			time.Sleep(testTimeoutHeartbeat * 2)
-
-			serviceEndpoint.Stop()
-			rs2 := NewSignerServiceEndpoint(
-				logger,
-				chainID,
-				types.NewMockPV(),
-				tc.dialer,
-			)
-			// let some pings pass
-			time.Sleep(testTimeoutHeartbeat3o2)
-			require.NoError(t, rs2.Start())
-			assert.True(t, rs2.IsRunning())
-			defer rs2.Stop()
-
-			// give the client some time to re-establish the conn to the remote signer
-			// should see sth like this in the logs:
-			//
-			// E[10016-01-10|17:12:46.128] Ping                                         err="remote signer timed out"
-			// I[10016-01-10|17:16:42.447] Re-created connection to remote signer       impl=SocketVal
-			time.Sleep(testTimeoutReadWrite * 2)
-		}()
-	}
-}
-
-func newSignerValidatorEndpoint(logger log.Logger, addr string, timeoutReadWrite time.Duration) *SignerValidatorEndpoint {
-	proto, address := cmn.ProtocolAndAddress(addr)
-
-	ln, err := net.Listen(proto, address)
-	logger.Info("Listening at", "proto", proto, "address", address)
-	if err != nil {
-		panic(err)
-	}
-
-	var listener net.Listener
-
-	if proto == "unix" {
-		unixLn := NewUnixListener(ln)
-		UnixListenerTimeoutAccept(testTimeoutAccept)(unixLn)
-		UnixListenerTimeoutReadWrite(timeoutReadWrite)(unixLn)
-		listener = unixLn
-	} else {
-		tcpLn := NewTCPListener(ln, ed25519.GenPrivKey())
-		TCPListenerTimeoutAccept(testTimeoutAccept)(tcpLn)
-		TCPListenerTimeoutReadWrite(timeoutReadWrite)(tcpLn)
-		listener = tcpLn
-	}
-
-	return NewSignerValidatorEndpoint(logger, listener)
-}
-
-func testSetupSocketPair(
-	t *testing.T,
-	chainID string,
-	privValidator types.PrivValidator,
-	addr string,
-	socketDialer SocketDialer,
-) (*SignerValidatorEndpoint, *SignerServiceEndpoint) {
-	var (
-		logger          = log.TestingLogger()
-		privVal         = privValidator
-		readyc          = make(chan struct{})
-		serviceEndpoint = NewSignerServiceEndpoint(
-			logger,
-			chainID,
-			privVal,
-			socketDialer,
-		)
-
-		thisConnTimeout   = testTimeoutReadWrite
-		validatorEndpoint = newSignerValidatorEndpoint(logger, addr, thisConnTimeout)
-	)
-
-	SignerValidatorEndpointSetHeartbeat(testTimeoutHeartbeat)(validatorEndpoint)
-	SignerServiceEndpointTimeoutReadWrite(testTimeoutReadWrite)(serviceEndpoint)
-	SignerServiceEndpointConnRetries(1e6)(serviceEndpoint)
-
-	testStartEndpoint(t, readyc, validatorEndpoint)
-
-	require.NoError(t, serviceEndpoint.Start())
-	assert.True(t, serviceEndpoint.IsRunning())
-
-	<-readyc
-
-	return validatorEndpoint, serviceEndpoint
-}
-
-func testReadWriteResponse(t *testing.T, resp RemoteSignerMsg, rsConn net.Conn) {
-	_, err := readMsg(rsConn)
-	require.NoError(t, err)
-
-	err = writeMsg(rsConn, resp)
-	require.NoError(t, err)
-}
-
-func testStartEndpoint(t *testing.T, readyCh chan struct{}, sc *SignerValidatorEndpoint) {
-	go func(sc *SignerValidatorEndpoint) {
-		require.NoError(t, sc.Start())
-		assert.True(t, sc.IsRunning())
-
-		readyCh <- struct{}{}
-	}(sc)
-}
-
-// testFreeTCPAddr claims a free port so we don't block on listener being ready.
-func testFreeTCPAddr(t *testing.T) string {
-	ln, err := net.Listen("tcp", "127.0.0.1:0")
-	require.NoError(t, err)
-	defer ln.Close()
-
-	return fmt.Sprintf("127.0.0.1:%d", ln.Addr().(*net.TCPAddr).Port)
-}

privval/socket_dialers_test.go

@@ -1,26 +1,49 @@
 package privval
 
 import (
+	"fmt"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
 	"github.com/tendermint/tendermint/crypto/ed25519"
 	cmn "github.com/tendermint/tendermint/libs/common"
 )
 
+func getDialerTestCases(t *testing.T) []dialerTestCase {
+	tcpAddr := GetFreeLocalhostAddrPort()
+	unixFilePath, err := testUnixAddr()
+	require.NoError(t, err)
+	unixAddr := fmt.Sprintf("unix://%s", unixFilePath)
+
+	return []dialerTestCase{
+		{
+			addr:   tcpAddr,
+			dialer: DialTCPFn(tcpAddr, testTimeoutReadWrite, ed25519.GenPrivKey()),
+		},
+		{
+			addr:   unixAddr,
+			dialer: DialUnixFn(unixFilePath),
+		},
+	}
+}
+
 func TestIsConnTimeoutForFundamentalTimeouts(t *testing.T) {
 	// Generate a networking timeout
-	dialer := DialTCPFn(testFreeTCPAddr(t), time.Millisecond, ed25519.GenPrivKey())
+	tcpAddr := GetFreeLocalhostAddrPort()
+	dialer := DialTCPFn(tcpAddr, time.Millisecond, ed25519.GenPrivKey())
 	_, err := dialer()
 	assert.Error(t, err)
 	assert.True(t, IsConnTimeout(err))
 }
 
 func TestIsConnTimeoutForWrappedConnTimeouts(t *testing.T) {
-	dialer := DialTCPFn(testFreeTCPAddr(t), time.Millisecond, ed25519.GenPrivKey())
+	tcpAddr := GetFreeLocalhostAddrPort()
+	dialer := DialTCPFn(tcpAddr, time.Millisecond, ed25519.GenPrivKey())
 	_, err := dialer()
 	assert.Error(t, err)
-	err = cmn.ErrorWrap(ErrConnTimeout, err.Error())
+	err = cmn.ErrorWrap(ErrConnectionTimeout, err.Error())
 	assert.True(t, IsConnTimeout(err))
 }

privval/socket_listeners.go

@@ -9,8 +9,8 @@ import (
 )
 
 const (
-	defaultTimeoutAcceptSeconds    = 3
-	defaultTimeoutReadWriteSeconds = 3
+	defaultTimeoutAcceptSeconds   = 3
+	defaultPingPeriodMilliseconds = 100
 )
 
 // timeoutError can be used to check if an error returned from the netp package

privval/utils.go

@@ -1,7 +1,12 @@
 package privval
 
 import (
+	"fmt"
+	"net"
+
+	"github.com/tendermint/tendermint/crypto/ed25519"
 	cmn "github.com/tendermint/tendermint/libs/common"
+	"github.com/tendermint/tendermint/libs/log"
 )
 
 // IsConnTimeout returns a boolean indicating whether the error is known to
@@ -9,7 +14,7 @@ import (
 // network timeouts, as well as ErrConnTimeout errors.
 func IsConnTimeout(err error) bool {
 	if cmnErr, ok := err.(cmn.Error); ok {
-		if cmnErr.Data() == ErrConnTimeout {
+		if cmnErr.Data() == ErrConnectionTimeout {
 			return true
 		}
 	}
@@ -18,3 +23,39 @@ func IsConnTimeout(err error) bool {
 	}
 	return false
 }
+
+// NewSignerListener creates a new SignerListenerEndpoint using the corresponding listen address
+func NewSignerListener(listenAddr string, logger log.Logger) (*SignerListenerEndpoint, error) {
+	var listener net.Listener
+
+	protocol, address := cmn.ProtocolAndAddress(listenAddr)
+	ln, err := net.Listen(protocol, address)
+	if err != nil {
+		return nil, err
+	}
+	switch protocol {
+	case "unix":
+		listener = NewUnixListener(ln)
+	case "tcp":
+		// TODO: persist this key so external signer can actually authenticate us
+		listener = NewTCPListener(ln, ed25519.GenPrivKey())
+	default:
+		return nil, fmt.Errorf(
+			"wrong listen address: expected either 'tcp' or 'unix' protocols, got %s",
+			protocol,
+		)
+	}
+
+	pve := NewSignerListenerEndpoint(logger.With("module", "privval"), listener)
+
+	return pve, nil
+}
+
+// GetFreeLocalhostAddrPort returns a free localhost:port address
+func GetFreeLocalhostAddrPort() string {
+	port, err := cmn.GetFreePort()
+	if err != nil {
+		panic(err)
+	}
+	return fmt.Sprintf("127.0.0.1:%d", port)
+}

privval/utils_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+
 	cmn "github.com/tendermint/tendermint/libs/common"
 )
 

tools/tm-signer-harness/internal/test_harness.go

@@ -49,7 +49,7 @@ var _ error = (*TestHarnessError)(nil)
 // with this version of Tendermint.
 type TestHarness struct {
 	addr             string
-	spv              *privval.SignerValidatorEndpoint
+	signerClient     *privval.SignerClient
 	fpv              *privval.FilePV
 	chainID          string
 	acceptRetries    int
@@ -101,14 +101,19 @@ func NewTestHarness(logger log.Logger, cfg TestHarnessConfig) (*TestHarness, err
 	}
 	logger.Info("Loaded genesis file", "chainID", st.ChainID)
 
-	spv, err := newTestHarnessSocketVal(logger, cfg)
+	spv, err := newTestHarnessListener(logger, cfg)
+	if err != nil {
+		return nil, newTestHarnessError(ErrFailedToCreateListener, err, "")
+	}
+
+	signerClient, err := privval.NewSignerClient(spv)
 	if err != nil {
 		return nil, newTestHarnessError(ErrFailedToCreateListener, err, "")
 	}
 
 	return &TestHarness{
 		addr:             cfg.BindAddr,
-		spv:              spv,
+		signerClient:     signerClient,
 		fpv:              fpv,
 		chainID:          st.ChainID,
 		acceptRetries:    cfg.AcceptRetries,
@@ -135,9 +140,11 @@ func (th *TestHarness) Run() {
 	th.logger.Info("Starting test harness")
 	accepted := false
 	var startErr error
+
 	for acceptRetries := th.acceptRetries; acceptRetries > 0; acceptRetries-- {
 		th.logger.Info("Attempting to accept incoming connection", "acceptRetries", acceptRetries)
-		if err := th.spv.Start(); err != nil {
+
+		if err := th.signerClient.WaitForConnection(10 * time.Millisecond); err != nil {
 			// if it wasn't a timeout error
 			if _, ok := err.(timeoutError); !ok {
 				th.logger.Error("Failed to start listener", "err", err)
@@ -149,6 +156,7 @@ func (th *TestHarness) Run() {
 			}
 			startErr = err
 		} else {
+			th.logger.Info("Accepted external connection")
 			accepted = true
 			break
 		}
@@ -182,8 +190,8 @@ func (th *TestHarness) Run() {
 func (th *TestHarness) TestPublicKey() error {
 	th.logger.Info("TEST: Public key of remote signer")
 	th.logger.Info("Local", "pubKey", th.fpv.GetPubKey())
-	th.logger.Info("Remote", "pubKey", th.spv.GetPubKey())
-	if th.fpv.GetPubKey() != th.spv.GetPubKey() {
+	th.logger.Info("Remote", "pubKey", th.signerClient.GetPubKey())
+	if th.fpv.GetPubKey() != th.signerClient.GetPubKey() {
 		th.logger.Error("FAILED: Local and remote public keys do not match")
 		return newTestHarnessError(ErrTestPublicKeyFailed, nil, "")
 	}
@@ -211,7 +219,7 @@ func (th *TestHarness) TestSignProposal() error {
 		Timestamp: time.Now(),
 	}
 	propBytes := prop.SignBytes(th.chainID)
-	if err := th.spv.SignProposal(th.chainID, prop); err != nil {
+	if err := th.signerClient.SignProposal(th.chainID, prop); err != nil {
 		th.logger.Error("FAILED: Signing of proposal", "err", err)
 		return newTestHarnessError(ErrTestSignProposalFailed, err, "")
 	}
@@ -222,7 +230,7 @@ func (th *TestHarness) TestSignProposal() error {
 		return newTestHarnessError(ErrTestSignProposalFailed, err, "")
 	}
 	// now validate the signature on the proposal
-	if th.spv.GetPubKey().VerifyBytes(propBytes, prop.Signature) {
+	if th.signerClient.GetPubKey().VerifyBytes(propBytes, prop.Signature) {
 		th.logger.Info("Successfully validated proposal signature")
 	} else {
 		th.logger.Error("FAILED: Proposal signature validation failed")
@@ -255,7 +263,7 @@ func (th *TestHarness) TestSignVote() error {
 		}
 		voteBytes := vote.SignBytes(th.chainID)
 		// sign the vote
-		if err := th.spv.SignVote(th.chainID, vote); err != nil {
+		if err := th.signerClient.SignVote(th.chainID, vote); err != nil {
 			th.logger.Error("FAILED: Signing of vote", "err", err)
 			return newTestHarnessError(ErrTestSignVoteFailed, err, fmt.Sprintf("voteType=%d", voteType))
 		}
@@ -266,7 +274,7 @@ func (th *TestHarness) TestSignVote() error {
 			return newTestHarnessError(ErrTestSignVoteFailed, err, fmt.Sprintf("voteType=%d", voteType))
 		}
 		// now validate the signature on the proposal
-		if th.spv.GetPubKey().VerifyBytes(voteBytes, vote.Signature) {
+		if th.signerClient.GetPubKey().VerifyBytes(voteBytes, vote.Signature) {
 			th.logger.Info("Successfully validated vote signature", "type", voteType)
 		} else {
 			th.logger.Error("FAILED: Vote signature validation failed", "type", voteType)
@@ -301,10 +309,9 @@ func (th *TestHarness) Shutdown(err error) {
 		}()
 	}
 
-	if th.spv.IsRunning() {
-		if err := th.spv.Stop(); err != nil {
-			th.logger.Error("Failed to cleanly stop listener: %s", err.Error())
-		}
+	err = th.signerClient.Close()
+	if err != nil {
+		th.logger.Error("Failed to cleanly stop listener: %s", err.Error())
 	}
 
 	if th.exitWhenComplete {
@@ -312,9 +319,8 @@ func (th *TestHarness) Shutdown(err error) {
 	}
 }
 
-// newTestHarnessSocketVal creates our client instance which we will use for
-// testing.
-func newTestHarnessSocketVal(logger log.Logger, cfg TestHarnessConfig) (*privval.SignerValidatorEndpoint, error) {
+// newTestHarnessListener creates our client instance which we will use for testing.
+func newTestHarnessListener(logger log.Logger, cfg TestHarnessConfig) (*privval.SignerListenerEndpoint, error) {
 	proto, addr := cmn.ProtocolAndAddress(cfg.BindAddr)
 	if proto == "unix" {
 		// make sure the socket doesn't exist - if so, try to delete it
@@ -329,7 +335,7 @@ func newTestHarnessSocketVal(logger log.Logger, cfg TestHarnessConfig) (*privval
 	if err != nil {
 		return nil, err
 	}
-	logger.Info("Listening at", "proto", proto, "addr", addr)
+	logger.Info("Listening", "proto", proto, "addr", addr)
 	var svln net.Listener
 	switch proto {
 	case "unix":
@@ -347,7 +353,7 @@ func newTestHarnessSocketVal(logger log.Logger, cfg TestHarnessConfig) (*privval
 		logger.Error("Unsupported protocol (must be unix:// or tcp://)", "proto", proto)
 		return nil, newTestHarnessError(ErrInvalidParameters, nil, fmt.Sprintf("Unsupported protocol: %s", proto))
 	}
-	return privval.NewSignerValidatorEndpoint(logger, svln), nil
+	return privval.NewSignerListenerEndpoint(logger, svln), nil
 }
 
 func newTestHarnessError(code int, err error, info string) *TestHarnessError {

tools/tm-signer-harness/internal/test_harness_test.go

@@ -3,19 +3,18 @@ package internal
 import (
 	"fmt"
 	"io/ioutil"
-	"net"
 	"os"
 	"testing"
 	"time"
 
-	"github.com/tendermint/tendermint/crypto"
-	"github.com/tendermint/tendermint/privval"
-	"github.com/tendermint/tendermint/types"
-
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	"github.com/tendermint/tendermint/crypto"
 	"github.com/tendermint/tendermint/crypto/ed25519"
 	"github.com/tendermint/tendermint/libs/log"
+	"github.com/tendermint/tendermint/privval"
+	"github.com/tendermint/tendermint/types"
 )
 
 const (
@@ -85,8 +84,8 @@ func TestRemoteSignerTestHarnessMaxAcceptRetriesReached(t *testing.T) {
 func TestRemoteSignerTestHarnessSuccessfulRun(t *testing.T) {
 	harnessTest(
 		t,
-		func(th *TestHarness) *privval.SignerServiceEndpoint {
-			return newMockRemoteSigner(t, th, th.fpv.Key.PrivKey, false, false)
+		func(th *TestHarness) *privval.SignerServer {
+			return newMockSignerServer(t, th, th.fpv.Key.PrivKey, false, false)
 		},
 		NoError,
 	)
@@ -95,8 +94,8 @@ func TestRemoteSignerTestHarnessSuccessfulRun(t *testing.T) {
 func TestRemoteSignerPublicKeyCheckFailed(t *testing.T) {
 	harnessTest(
 		t,
-		func(th *TestHarness) *privval.SignerServiceEndpoint {
-			return newMockRemoteSigner(t, th, ed25519.GenPrivKey(), false, false)
+		func(th *TestHarness) *privval.SignerServer {
+			return newMockSignerServer(t, th, ed25519.GenPrivKey(), false, false)
 		},
 		ErrTestPublicKeyFailed,
 	)
@@ -105,8 +104,8 @@ func TestRemoteSignerPublicKeyCheckFailed(t *testing.T) {
 func TestRemoteSignerProposalSigningFailed(t *testing.T) {
 	harnessTest(
 		t,
-		func(th *TestHarness) *privval.SignerServiceEndpoint {
-			return newMockRemoteSigner(t, th, th.fpv.Key.PrivKey, true, false)
+		func(th *TestHarness) *privval.SignerServer {
+			return newMockSignerServer(t, th, th.fpv.Key.PrivKey, true, false)
 		},
 		ErrTestSignProposalFailed,
 	)
@@ -115,28 +114,30 @@ func TestRemoteSignerProposalSigningFailed(t *testing.T) {
 func TestRemoteSignerVoteSigningFailed(t *testing.T) {
 	harnessTest(
 		t,
-		func(th *TestHarness) *privval.SignerServiceEndpoint {
-			return newMockRemoteSigner(t, th, th.fpv.Key.PrivKey, false, true)
+		func(th *TestHarness) *privval.SignerServer {
+			return newMockSignerServer(t, th, th.fpv.Key.PrivKey, false, true)
 		},
 		ErrTestSignVoteFailed,
 	)
 }
 
-func newMockRemoteSigner(t *testing.T, th *TestHarness, privKey crypto.PrivKey, breakProposalSigning bool, breakVoteSigning bool) *privval.SignerServiceEndpoint {
-	return privval.NewSignerServiceEndpoint(
+func newMockSignerServer(t *testing.T, th *TestHarness, privKey crypto.PrivKey, breakProposalSigning bool, breakVoteSigning bool) *privval.SignerServer {
+	mockPV := types.NewMockPVWithParams(privKey, breakProposalSigning, breakVoteSigning)
+
+	dialerEndpoint := privval.NewSignerDialerEndpoint(
 		th.logger,
-		th.chainID,
-		types.NewMockPVWithParams(privKey, breakProposalSigning, breakVoteSigning),
 		privval.DialTCPFn(
 			th.addr,
 			time.Duration(defaultConnDeadline)*time.Millisecond,
 			ed25519.GenPrivKey(),
 		),
 	)
+
+	return privval.NewSignerServer(dialerEndpoint, th.chainID, mockPV)
 }
 
 // For running relatively standard tests.
-func harnessTest(t *testing.T, rsMaker func(th *TestHarness) *privval.SignerServiceEndpoint, expectedExitCode int) {
+func harnessTest(t *testing.T, signerServerMaker func(th *TestHarness) *privval.SignerServer, expectedExitCode int) {
 	cfg := makeConfig(t, 100, 3)
 	defer cleanup(cfg)
 
@@ -148,10 +149,10 @@ func harnessTest(t *testing.T, rsMaker func(th *TestHarness) *privval.SignerServ
 		th.Run()
 	}()
 
-	rs := rsMaker(th)
-	require.NoError(t, rs.Start())
-	assert.True(t, rs.IsRunning())
-	defer rs.Stop()
+	ss := signerServerMaker(th)
+	require.NoError(t, ss.Start())
+	assert.True(t, ss.IsRunning())
+	defer ss.Stop()
 
 	<-donec
 	assert.Equal(t, expectedExitCode, th.exitCode)
@@ -159,7 +160,7 @@ func harnessTest(t *testing.T, rsMaker func(th *TestHarness) *privval.SignerServ
 
 func makeConfig(t *testing.T, acceptDeadline, acceptRetries int) TestHarnessConfig {
 	return TestHarnessConfig{
-		BindAddr:         testFreeTCPAddr(t),
+		BindAddr:         privval.GetFreeLocalhostAddrPort(),
 		KeyFile:          makeTempFile("tm-testharness-keyfile", keyFileContents),
 		StateFile:        makeTempFile("tm-testharness-statefile", stateFileContents),
 		GenesisFile:      makeTempFile("tm-testharness-genesisfile", genesisFileContents),
@@ -191,12 +192,3 @@ func makeTempFile(name, content string) string {
 	}
 	return tempFile.Name()
 }
-
-// testFreeTCPAddr claims a free port so we don't block on listener being ready.
-func testFreeTCPAddr(t *testing.T) string {
-	ln, err := net.Listen("tcp", "127.0.0.1:0")
-	require.NoError(t, err)
-	defer ln.Close()
-
-	return fmt.Sprintf("127.0.0.1:%d", ln.Addr().(*net.TCPAddr).Port)
-}

types/priv_validator.go

@@ -12,6 +12,7 @@ import (
 // PrivValidator defines the functionality of a local Tendermint validator
 // that signs votes and proposals, and never double signs.
 type PrivValidator interface {
+	// TODO: Extend the interface to return errors too. Issue: https://github.com/tendermint/tendermint/issues/3602
 	GetPubKey() crypto.PubKey
 
 	SignVote(chainID string, vote *Vote) error