From 1f260b6beed09b666b5bfa36518b930cd400c711 Mon Sep 17 00:00:00 2001
From: holgerd77 <Holger.Drewes@gmail.com>
Date: Thu, 30 Nov 2017 15:44:12 +0100
Subject: [PATCH] Added some extra failing test cases for merkle proof
 generation/verification

---
 proof.js      | 20 ++++++++++----------
 test/proof.js | 28 ++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 10 deletions(-)

diff --git a/proof.js b/proof.js
index 8f20c64..d474413 100644
--- a/proof.js
+++ b/proof.js
@@ -7,7 +7,7 @@ const matchingNibbleLength = require('./util').matchingNibbleLength
  * @method Trie.prove
  * @param {Trie} trie
  * @param {String} key
- * @param {Function} cb A callback `Function` (arguments {Error} `err`, {Array.<TrieNode>} `proof`) 
+ * @param {Function} cb A callback `Function` (arguments {Error} `err`, {Array.<TrieNode>} `proof`)
  */
 exports.prove = function (trie, key, cb) {
   var nodes
@@ -34,7 +34,7 @@ exports.prove = function (trie, key, cb) {
  * @param {Buffer} rootHash
  * @param {String} key
  * @param {Array.<TrieNode>} proof
- * @param {Function} cb A callback `Function` (arguments {Error} `err`, {String} `val`) 
+ * @param {Function} cb A callback `Function` (arguments {Error} `err`, {String} `val`)
  */
 exports.verifyProof = function (rootHash, key, proof, cb) {
   key = TrieNode.stringToNibbles(key)
@@ -43,14 +43,14 @@ exports.verifyProof = function (rootHash, key, proof, cb) {
     var p = ethUtil.toBuffer(proof[i])
     var hash = ethUtil.sha3(proof[i])
     if (Buffer.compare(hash, wantHash)) {
-      return cb(new Error('bad proof node ' + i + ': hash mismatch'))
+      return cb(new Error('Bad proof node ' + i + ': hash mismatch'))
     }
     var node = new TrieNode(ethUtil.rlp.decode(p))
     var cld
     if (node.type === 'branch') {
       if (key.length === 0) {
         if (i !== proof.length - 1) {
-          return cb(new Error('additional nodes at end of proof'))
+          return cb(new Error('Additional nodes at end of proof (branch)'))
         }
         return cb(null, node.value)
       }
@@ -59,15 +59,15 @@ exports.verifyProof = function (rootHash, key, proof, cb) {
       if (cld.length === 2) {
         var embeddedNode = new TrieNode(cld)
         if (i !== proof.length - 1) {
-          return cb(new Error('Key does not match with the proof one'))
+          return cb(new Error('Additional nodes at end of proof (embeddedNode)'))
         }
 
         if (matchingNibbleLength(embeddedNode.key, key) !== embeddedNode.key.length) {
-          return cb(new Error('Key does not match with the proof one'))
+          return cb(new Error('Key length does not match with the proof one (embeddedNode)'))
         }
         key = key.slice(embeddedNode.key.length)
         if (key.length !== 0) {
-          return cb(new Error('Key does not match with the proof one'))
+          return cb(new Error('Key does not match with the proof one (embeddedNode)'))
         }
         return cb(null, embeddedNode.value)
       } else {
@@ -75,13 +75,13 @@ exports.verifyProof = function (rootHash, key, proof, cb) {
       }
     } else if ((node.type === 'extention') || (node.type === 'leaf')) {
       if (matchingNibbleLength(node.key, key) !== node.key.length) {
-        return cb(new Error('Key does not match with the proof one'))
+        return cb(new Error('Key does not match with the proof one (extention|leaf)'))
       }
       cld = node.value
       key = key.slice(node.key.length)
       if (key.length === 0) {
         if (i !== proof.length - 1) {
-          return cb(new Error('Key does not match with the proof one'))
+          return cb(new Error('Additional nodes at end of proof (extention|leaf)'))
         }
         return cb(null, cld)
       } else {
@@ -91,5 +91,5 @@ exports.verifyProof = function (rootHash, key, proof, cb) {
       return cb(new Error('Invalid node type'))
     }
   }
-  cb(new Error('unexpected end of proof'))
+  cb(new Error('Unexpected end of proof'))
 }
diff --git a/test/proof.js b/test/proof.js
index 56464c7..28515c0 100644
--- a/test/proof.js
+++ b/test/proof.js
@@ -36,6 +36,34 @@ tape('simple merkle proofs generation and verification', function (tester) {
             cb()
           })
         })
+      },
+      function (cb) {
+        Trie.prove(trie, 'key2bb', function (err, prove) {
+          if (err) return cb(err)
+          Trie.verifyProof(trie.root, 'randomkey', prove, function (err, val) {
+            t.notEqual(err, null, 'Expected error: ' + err.message)
+            cb()
+          })
+        })
+      },
+      function (cb) {
+        Trie.prove(trie, 'key2bb', function (err, prove) {
+          if (err) return cb(err)
+          Trie.verifyProof(trie.root, 'key2b', prove, function (err, val) {
+            t.notEqual(err, null, 'Expected error: ' + err.message)
+            cb()
+          })
+        })
+      },
+      function (cb) {
+        Trie.prove(trie, 'key2bb', function (err, prove) {
+          if (err) return cb(err)
+          prove.push(Buffer.from('123456'))
+          Trie.verifyProof(trie.root, 'key2b', prove, function (err, val) {
+            t.notEqual(err, null, 'Expected error: ' + err.message)
+            cb()
+          })
+        })
       }
     ], function (err) {
       t.end(err)