From 9046dbde4fe8b71df2dbb0b5a0091d59d29adb95 Mon Sep 17 00:00:00 2001
From: Arceliar <Arceliar@users.noreply.github.com>
Date: Sun, 25 Nov 2018 13:06:54 -0600
Subject: [PATCH] remove sigManager, it seems safer to just burn the CPU than
 to store a map of strings of potentially arbitrary length

---
 src/yggdrasil/core.go      |  2 -
 src/yggdrasil/peer.go      |  2 +-
 src/yggdrasil/router.go    |  1 -
 src/yggdrasil/signature.go | 95 --------------------------------------
 4 files changed, 1 insertion(+), 99 deletions(-)
 delete mode 100644 src/yggdrasil/signature.go

diff --git a/src/yggdrasil/core.go b/src/yggdrasil/core.go
index 2f60a1b..9b9bcc1 100644
--- a/src/yggdrasil/core.go
+++ b/src/yggdrasil/core.go
@@ -22,7 +22,6 @@ type Core struct {
 	sigPriv     sigPrivKey
 	switchTable switchTable
 	peers       peers
-	sigs        sigManager
 	sessions    sessions
 	router      router
 	dht         dht
@@ -50,7 +49,6 @@ func (c *Core) init(bpub *boxPubKey,
 	c.boxPub, c.boxPriv = *bpub, *bpriv
 	c.sigPub, c.sigPriv = *spub, *spriv
 	c.admin.core = c
-	c.sigs.init()
 	c.searches.init(c)
 	c.dht.init(c)
 	c.sessions.init(c)
diff --git a/src/yggdrasil/peer.go b/src/yggdrasil/peer.go
index e4d0998..67aa805 100644
--- a/src/yggdrasil/peer.go
+++ b/src/yggdrasil/peer.go
@@ -316,7 +316,7 @@ func (p *peer) handleSwitchMsg(packet []byte) {
 		sigMsg.Hops = msg.Hops[:idx]
 		loc.coords = append(loc.coords, hop.Port)
 		bs := getBytesForSig(&hop.Next, &sigMsg)
-		if !p.core.sigs.check(&prevKey, &hop.Sig, bs) {
+		if !verify(&prevKey, bs, &hop.Sig) {
 			p.core.peers.removePeer(p.port)
 		}
 		prevKey = hop.Next
diff --git a/src/yggdrasil/router.go b/src/yggdrasil/router.go
index 41e2863..b482476 100644
--- a/src/yggdrasil/router.go
+++ b/src/yggdrasil/router.go
@@ -121,7 +121,6 @@ func (r *router) mainLoop() {
 				r.core.switchTable.doMaintenance()
 				r.core.dht.doMaintenance()
 				r.core.sessions.cleanup()
-				r.core.sigs.cleanup()
 				util_getBytes() // To slowly drain things
 			}
 		case f := <-r.admin:
diff --git a/src/yggdrasil/signature.go b/src/yggdrasil/signature.go
deleted file mode 100644
index 12a3d37..0000000
--- a/src/yggdrasil/signature.go
+++ /dev/null
@@ -1,95 +0,0 @@
-package yggdrasil
-
-// This is where we record which signatures we've previously checked
-// It's so we can avoid needlessly checking them again
-
-import (
-	"sync"
-	"time"
-)
-
-// This keeps track of what signatures have already been checked.
-// It's used to skip expensive crypto operations, given that many signatures are likely to be the same for the average node's peers.
-type sigManager struct {
-	mutex       sync.RWMutex
-	checked     map[sigBytes]knownSig
-	lastCleaned time.Time
-}
-
-// Represents a known signature.
-// Includes the key, the signature bytes, the bytes that were signed, and the time it was last used.
-type knownSig struct {
-	key  sigPubKey
-	sig  sigBytes
-	bs   []byte
-	time time.Time
-}
-
-// Initializes the signature manager.
-func (m *sigManager) init() {
-	m.checked = make(map[sigBytes]knownSig)
-}
-
-// Checks if a key and signature match the supplied bytes.
-// If the same key/sig/bytes have been checked before, it returns true from the cached results.
-// If not, it checks the key, updates it in the cache if successful, and returns the checked results.
-func (m *sigManager) check(key *sigPubKey, sig *sigBytes, bs []byte) bool {
-	if m.isChecked(key, sig, bs) {
-		return true
-	}
-	verified := verify(key, bs, sig)
-	if verified {
-		m.putChecked(key, sig, bs)
-	}
-	return verified
-}
-
-// Checks the cache to see if this key/sig/bytes combination has already been verified.
-// Returns true if it finds a match.
-func (m *sigManager) isChecked(key *sigPubKey, sig *sigBytes, bs []byte) bool {
-	m.mutex.RLock()
-	defer m.mutex.RUnlock()
-	k, isIn := m.checked[*sig]
-	if !isIn {
-		return false
-	}
-	if k.key != *key || k.sig != *sig || len(bs) != len(k.bs) {
-		return false
-	}
-	for idx := 0; idx < len(bs); idx++ {
-		if bs[idx] != k.bs[idx] {
-			return false
-		}
-	}
-	k.time = time.Now()
-	return true
-}
-
-// Puts a new result into the cache.
-// This result is then used by isChecked to skip the expensive crypto verification if it's needed again.
-// This is useful because, for nodes with multiple peers, there is often a lot of overlap between the signatures provided by each peer.
-func (m *sigManager) putChecked(key *sigPubKey, newsig *sigBytes, bs []byte) {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-	k := knownSig{key: *key, sig: *newsig, bs: bs, time: time.Now()}
-	m.checked[*newsig] = k
-}
-
-func (m *sigManager) cleanup() {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-	if time.Since(m.lastCleaned) < time.Minute {
-		return
-	}
-	for s, k := range m.checked {
-		if time.Since(k.time) > time.Minute {
-			delete(m.checked, s)
-		}
-	}
-	newChecked := make(map[sigBytes]knownSig, len(m.checked))
-	for s, k := range m.checked {
-		newChecked[s] = k
-	}
-	m.checked = newChecked
-	m.lastCleaned = time.Now()
-}