fix(GET /encryption/publickey): Search blockchain for a public key associated with an address

src/app.js

@@ -38,6 +38,7 @@ const xpubV3 = require('./routes/v3/xpub')
 const BlockbookV3 = require('./routes/v3/blockbook')
 const Ninsight = require('./routes/v3/ninsight')
 const ElectrumXV3 = require('./routes/v3/electrumx')
+const EncryptionV3 = require('./routes/v3/encryption')
 
 require('dotenv').config()
 
@@ -50,6 +51,7 @@ const slpV3 = new SlpV3()
 const blockbookV3 = new BlockbookV3()
 const electrumxv3 = new ElectrumXV3()
 electrumxv3.connect()
+const encryptionv3 = new EncryptionV3()
 
 const app = express()
 
@@ -118,6 +120,7 @@ app.use(`/${v3prefix}/` + 'slp', slpV3.router)
 app.use(`/${v3prefix}/` + 'xpub', xpubV3.router)
 app.use(`/${v3prefix}/` + 'blockbook', blockbookV3.router)
 app.use(`/${v3prefix}/` + 'electrumx', electrumxv3.router)
+app.use(`/${v3prefix}/` + 'encryption', encryptionv3.router)
 
 const ninsight = new Ninsight()
 app.use(`/${v3prefix}/` + 'ninsight', ninsight.router)

src/routes/v3/encryption.js

@@ -18,6 +18,14 @@ const routeUtils = new RouteUtils()
 const BCHJS = require('@chris.troutner/bch-js')
 const bchjs = new BCHJS()
 
+// Use Blockbook for getting indexer data.
+const Blockbook = require('./blockbook')
+const blockbook = new Blockbook()
+
+// Use RawTransactions library for getting raw blockchain data.
+const RawTransactions = require('./full-node/rawtransactions')
+const rawTransactions = new RawTransactions()
+
 let _this
 
 class Encryption {
@@ -28,10 +36,12 @@ class Encryption {
     _this.axios = axios
     _this.routeUtils = routeUtils
     _this.bchjs = bchjs
+    _this.blockbook = blockbook
+    _this.rawTransactions = rawTransactions
 
     _this.router = router
     _this.router.get('/', _this.root)
-    // _this.router.get('/publickey', _this.getPublicKey)
+    _this.router.get('/publickey/:address', _this.getPublicKey)
   }
 
   // DRY error handler.
@@ -60,6 +70,113 @@ class Encryption {
   root (req, res, next) {
     return res.json({ status: 'encryption' })
   }
+
+  /**
+   * @api {get} /encryption/publickey/{addr} Get public key for a BCH address.
+   * @apiName Get encryption key for bch address
+   * @apiGroup Encryption
+   * @apiDescription Searches the blockchain for a public key associated with a BCH address.
+   *
+   *
+   * @apiExample Example usage:
+   * curl -X GET "https://api.fullstack.cash/v3/encryption/publickey/bitcoincash:qrdka2205f4hyukutc2g0s6lykperc8nsu5u2ddpqf" -H "accept: application/json"
+   *
+   */
+  async getPublicKey (req, res, next) {
+    try {
+      const address = req.params.address
+
+      // Reject if address is an array.
+      if (Array.isArray(address)) {
+        res.status(400)
+        return res.json({
+          success: false,
+          error: 'address can not be an array.'
+        })
+      }
+
+      const cashAddr = _this.bchjs.Address.toCashAddress(address)
+
+      // Prevent a common user error. Ensure they are using the correct network address.
+      const networkIsValid = _this.routeUtils.validateNetwork(cashAddr)
+      if (!networkIsValid) {
+        res.status(400)
+        return res.json({
+          success: false,
+          error:
+            'Invalid network. Trying to use a testnet address on mainnet, or vice versa.'
+        })
+      }
+
+      wlogger.debug(
+        'Executing encryption/getPublicKey with this address: ',
+        cashAddr
+      )
+
+      // Retrieve the transaction history for this address.
+      const balance = await _this.blockbook.balanceFromBlockbook(cashAddr)
+      // console.log(`balance: ${JSON.stringify(balance, null, 2)}`)
+
+      const txHistory = balance.txids
+      // console.log(`txHistory: ${JSON.stringify(txHistory, null, 2)}`)
+
+      if (txHistory.length === 0) {
+        throw new Error('No transaction history.')
+      }
+
+      // Loop through the transaction history and search for the public key.
+      for (let i = 0; i < txHistory.length; i++) {
+        const thisTx = txHistory[i]
+
+        const txDetails = await _this.rawTransactions.getRawTransactionsFromNode(
+          thisTx,
+          true
+        )
+        // console.log(`txDetails: ${JSON.stringify(txDetails, null, 2)}`)
+
+        const vin = txDetails.vin
+
+        // Loop through each input.
+        for (let j = 0; j < vin.length; j++) {
+          const thisVin = vin[j]
+          // console.log(`thisVin: ${JSON.stringify(thisVin, null, 2)}`)
+
+          // Extract the script signature.
+          const scriptSig = thisVin.scriptSig.asm.split(' ')
+          // console.log(`scriptSig: ${JSON.stringify(scriptSig, null, 2)}`)
+
+          // Extract the public key from the script signature.
+          const pubKey = scriptSig[scriptSig.length - 1]
+          // console.log(`pubKey: ${pubKey}`)
+
+          // Generate cash address from public key.
+          const keyBuf = Buffer.from(pubKey, 'hex')
+          const ec = _this.bchjs.ECPair.fromPublicKey(keyBuf)
+          const cashAddr2 = _this.bchjs.ECPair.toCashAddress(ec)
+          // console.log(`cashAddr2: ${cashAddr2}`)
+
+          // If public keys match, this is the correct public key.
+          if (cashAddr === cashAddr2) {
+            res.status(200)
+            return res.json({
+              success: true,
+              publicKey: pubKey
+            })
+          }
+        }
+      }
+
+      res.status(200)
+      return res.json({
+        success: false,
+        publicKey: 'not found'
+      })
+    } catch (err) {
+      wlogger.error('Error in encryption.js/getPublicKey().', err)
+
+      return _this.errorHandler(err, res)
+    }
+  }
 }
 
 module.exports = Encryption

src/util/winston-logging.js

@@ -48,7 +48,7 @@ var wlogger = winston.createLogger({
 wlogger.add(
   new winston.transports.Console({
     format: winston.format.simple(),
-    level: "info"
+    level: 'info'
   })
 )
 */