request.go

package single

import (
	"bytes"
	"github.com/pkg/errors"
	jww "github.com/spf13/jwalterweatherman"
	"gitlab.com/elixxir/client/cmix"
	"gitlab.com/elixxir/client/cmix/identity/receptionID"
	cmixMsg "gitlab.com/elixxir/client/cmix/message"
	"gitlab.com/elixxir/client/cmix/rounds"
	"gitlab.com/elixxir/client/single/message"
	"gitlab.com/elixxir/crypto/contact"
	"gitlab.com/elixxir/crypto/cyclic"
	"gitlab.com/elixxir/crypto/e2e/auth"
	"gitlab.com/elixxir/crypto/e2e/singleUse"
	"gitlab.com/xx_network/crypto/csprng"
	"gitlab.com/xx_network/primitives/id"
	"gitlab.com/xx_network/primitives/id/ephemeral"
	"gitlab.com/xx_network/primitives/netTime"
	"io"
	"sync"
	"sync/atomic"
	"time"
)

// Error messages.
const (
	// TransmitRequest
	errPayloadSize     = "size of payload %d exceeds the maximum size of %d (%s for %s)"
	errNetworkHealth   = "cannot send singe-use request when the network is not healthy"
	errMakeDhKeys      = "failed to generate DH keys (%s for %s): %+v"
	errMakeIDs         = "failed to generate IDs (%s for %s): %+v"
	errAddFingerprint  = "failed to add fingerprint %d of %d: %+v (%s for %s)"
	errSendRequest     = "failed to send %s request to %s: %+v"
	errSendRequestPart = "%d requests failed to send, the request will be handleable and will time out"

	// generateDhKeys
	errGenerateInGroup = "failed to generate private key in group: %+v"

	// makeIDs
	errMakeNonce      = "failed to generate nonce: %+v"
	errNewEphemeralID = "failed to generate address ID from newly generated ID: %+v"

	// waitForTimeout
	errResponseTimeout = "waiting for response to single-use request timed out after %s"
)

// Maximum number of request part cMix messages.
const maxNumRequestParts = 255

// GetMaxRequestSize returns the maximum size of a request payload.
func GetMaxRequestSize(net Cmix, e2eGrp *cyclic.Group) int {
	payloadSize := message.GetRequestPayloadSize(
		net.GetMaxMessageLength(), e2eGrp.GetP().ByteLen())
	requestSize := message.GetRequestContentsSize(payloadSize)
	requestPartSize := message.GetRequestPartContentsSize(
		net.GetMaxMessageLength())
	return requestSize + (maxNumRequestParts * requestPartSize)
}

/* Single is a system which allows for an end-to-end encrypted anonymous request
   to be sent to another cMix client, and for them to respond. The system allows
   for communication over the mixnet without an interactive key negotiation
   because the payload inherently carries the negotiation with it. When sending
   a new request, a client create a new discreet log DH keypair as well as a new
   ID. As a result of the fact that the client never identifies itself, the
   system allows the client to stay anonymous while contacting the remote.
*/

// TransmitRequest sends a request to the recipient with the given tag