ipfs connection to local or embedded node (#86)

* handle ipfs connection in view fallback to embedded if local doesn't work add buffer webpack plugin * fallback to fetching from gateways add verification of ipfs content can input local node address remove ipfs-core and ipfs-provider Co-authored-by: stobiewan <[email protected]>
dapphub · Apr 19, 2022 · 78bb61b · 78bb61b
1 parent 013ddc0
commit 78bb61b
Show file tree

Hide file tree

Showing 5 changed files with 75 additions and 41 deletions.
diff --git a/dist/index.html b/dist/index.html
@@ -12,20 +12,26 @@
   #result {
       white-space: pre;
   }
-
+  #localNode {
+      width: 210px;
+  }
 </style>
 </head>
 <body>
 <h1>dmap</h1>
 
-<label for="dpath">dmap://</label>
-<input type="text" id="dpath" name="dpath" value="free.weth">
-<input type="button" id="btnGet" value="Get">
+<div>
+    <label for="localNode">ipfs node</label>
+    <input type="text" id="localNode" name="localNode" value="/ip4/127.0.0.1/tcp/5001" title="optional">
+</div>
 
-<div id="result"></div>
+<div>
+    <label for="dpath">dmap://</label>
+    <input type="text" id="dpath" name="dpath" value="free.weth">
+    <input type="button" id="btnGet" value="Get">
+</div>
 
-<!--<script defer src="dependencies.js" crossorigin="no-cors"></script>-->
-<!--<script defer src="main.js"></script>-->
+<div id="result"></div>
 
 <script defer src="dependencies.js"></script>
 <script defer src="main.js"></script>

diff --git a/dmap.js b/dmap.js
@@ -1,9 +1,6 @@
 const ebnf = require('ebnf')
-const multiformats = require('multiformats')
-
 const ethers = require('ethers')
-const { b32 } = require('minihat');
-
+const multiformats = require('multiformats')
 const abi    = require('./artifacts/core/dmap.sol/Dmap.json').abi
 const dmap_i = new ethers.utils.Interface(abi)
 
@@ -91,11 +88,11 @@ lib.walk = async (dmap, path) => {
         if (zone === '0x' + '00'.repeat(20)) {
             fail(`zero register`)
         }
-        const fullname = '0x' + lib._strToHex(step.name) + '00'.repeat(32-step.name.length);
+        const fullname = '0x' + Buffer.from(step.name).toString('hex') + '00'.repeat(32-step.name.length);
         [meta, data] = await lib.get(dmap, zone, fullname)
         if (step.locked) {
             need(ctx.locked, `Encountered ':' in unlocked subpath`)
-            need((lib._hexToArrayBuffer(meta)[0] & lib.FLAG_LOCK) !== 0, `Entry is not locked`)
+            need((Buffer.from(meta.slice(2), 'hex')[0] & lib.FLAG_LOCK) !== 0, `Entry is not locked`)
             ctx.locked = true
         }
         ctx.locked = step.locked
@@ -118,8 +115,8 @@ lib.prepareCID = (cidStr, lock) => {
 }
 
 lib.unpackCID = (metaStr, dataStr) => {
-    const meta = lib._hexToArrayBuffer(metaStr)
-    const data = lib._hexToArrayBuffer(dataStr)
+    const meta = Buffer.from(metaStr.slice(2), 'hex')
+    const data = Buffer.from(dataStr.slice(2), 'hex')
     const prefixLen = meta[prefLenIndex]
     const specs = multiformats.CID.inspectBytes(meta.slice(-prefixLen))
     const hashLen = specs.digestSize
@@ -135,15 +132,3 @@ lib.readCID = async (dmap, path) => {
     const packed = await lib.walk(dmap, path)
     return lib.unpackCID(packed.meta, packed.data)
 }
-
-lib._hexToArrayBuffer = hex => {
-    const bytes = []
-    for (let c = 2; c < hex.length; c += 2)
-        bytes.push(parseInt(hex.slice(c, c + 2), 16))
-    return new Uint8Array(bytes)
-}
-
-lib._strToHex = str => {
-    let codes =  str.split('').map(c => c.charCodeAt(0))
-    return codes.map(c => c.toString(16)).join('')
-}
diff --git a/package.json b/package.json
@@ -11,8 +11,8 @@
     "@nomiclabs/hardhat-ethers": "^2.0.5",
     "@types/mocha": "^9.0.0",
     "hardhat": "^2.8.3",
+    "ipfs-http-client": "^56.0.2",
     "minihat": "^0.0.5",
-    "v8": "^0.1.0",
     "web3-utils": "^1.7.1",
     "webpack": "^5.70.0",
     "webpack-cli": "^4.9.2"

diff --git a/view/app.js b/view/app.js
@@ -1,13 +1,50 @@
 import { ethers } from 'ethers'
-const dpack = require('@etherpacks/dpack')
+import { CID } from 'multiformats/cid'
+import { sha256 } from 'multiformats/hashes/sha2'
 const dmap = require('../dmap.js')
 const dmapAddress = '0x7fA88e1014B0640833a03ACfEC71F242b5fBDC85'
 const dmapArtifact = require('../artifacts/core/dmap.sol/Dmap.json')
+const IPFS = require('ipfs-http-client')
 
-window.onload =()=> {
-    const $ = document.querySelector.bind(document);
-    const result = $('#result')
+const gateways = ['https://ipfs.fleek.co/ipfs/',
+                  'https://gateway.pinata.cloud/ipfs/',
+                  'https://cloudflare-ipfs.com/ipfs/',
+                  'https://storry.tv/ipfs/',
+                  'https://ipfs.io/ipfs/',
+                  'https://hub.textile.io/ipfs/']
+
+const resolveCID = async (cid, targetDigest, nodeAddress) => {
+    const verify = async bytes => {
+        const hash = await sha256.digest(bytes)
+        const resultDigest = JSON.stringify(hash.digest)
+        return targetDigest === resultDigest
+    }
+    const node = IPFS.create(nodeAddress)
+    const catResponse = await node.cat(cid)
+    // initially handle only single chunk verification and sha256
+    try {
+        const chunk = await catResponse.next()
+        if(await verify(chunk.value)) {
+            return chunk.value
+        }
+    } catch(e) {}
 
+    for (const gateway of gateways) {
+        const url = gateway + cid
+        try {
+            const response = await fetch(url);
+            const reader = response.body.getReader();
+            let readRes = await reader.read();
+            if (await verify(readRes.value)) {
+                return readRes.value
+            }
+        } catch (e) {}
+    }
+    throw 'unable to resolve cid'
+}
+
+window.onload = async() => {
+    const $ = document.querySelector.bind(document);
     const line =s=> { $('#result').textContent += s + '\n' }
 
     $('#btnGet').addEventListener('click', async () =>  {
@@ -32,18 +69,18 @@ window.onload =()=> {
         }
 
         try {
-            // display json content from a CID if we can
-            const cidResult = dmap.unpackCID(walkResult.meta, walkResult.data)
-            line(`ipfs: ${cidResult}`)
-            const ipfsResult = await dpack.getIpfsJson(cidResult)
-            line(JSON.stringify(ipfsResult, null, 4))
+            // display ipfs content from a CID if we can, otherwise display as text
+            const cid = dmap.unpackCID(walkResult.meta, walkResult.data)
+            line(`ipfs: ${cid}`)
+            const targetDigest = JSON.stringify(CID.parse(cid).multihash.digest)
+            const resolved = await resolveCID(cid, targetDigest, $('#localNode').value)
+            let utf8decoder = new TextDecoder()
+            line(utf8decoder.decode(resolved))
         }
         catch(e){
-            // otherwise show text
             let utf8decoder = new TextDecoder()
-            const bytes = dmap._hexToArrayBuffer(walkResult.data)
-            let i
-            for (i = 0; i < bytes.length; i++) {
+            const bytes = Buffer.from(walkResult.data.slice(2), 'hex')
+            for (var i = 0; i < bytes.length; i++) {
                 if (bytes[bytes.length -1 - i] !== 0) {
                     break
                 }

diff --git a/webpack.config.js b/webpack.config.js
@@ -1,4 +1,5 @@
 const path = require('path');
+const webpack = require('webpack');
 
 module.exports = {
     mode: 'production',
@@ -9,6 +10,11 @@ module.exports = {
         path: path.resolve(__dirname, 'dist'),
         filename: '[name].js',
     },
+    plugins: [
+        new webpack.ProvidePlugin({
+            Buffer: ['buffer', 'Buffer'],
+        })
+    ],
     optimization: {
         minimize: false,
         splitChunks: {