Factor out some cashier code into common library

4 files changed, 5 insertions, 279 deletions

diff --git a/cashier/src/main/java/net/taler/cashier/withdraw/NfcManager.kt b/cashier/src/main/java/net/taler/cashier/withdraw/NfcManager.kt
deleted file mode 100644
index a487b5f..0000000
--- a/cashier/src/main/java/net/taler/cashier/withdraw/NfcManager.kt
+++ /dev/null
@@ -1,234 +0,0 @@
-/*
- * This file is part of GNU Taler
- * (C) 2020 Taler Systems S.A.
- *
- * GNU Taler is free software; you can redistribute it and/or modify it under the
- * terms of the GNU General Public License as published by the Free Software
- * Foundation; either version 3, or (at your option) any later version.
- *
- * GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
- * A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
- */
-
-package net.taler.cashier.withdraw
-
-import android.app.Activity
-import android.content.Context
-import android.nfc.NfcAdapter
-import android.nfc.NfcAdapter.FLAG_READER_NFC_A
-import android.nfc.NfcAdapter.FLAG_READER_SKIP_NDEF_CHECK
-import android.nfc.NfcAdapter.getDefaultAdapter
-import android.nfc.Tag
-import android.nfc.tech.IsoDep
-import android.util.Log
-import net.taler.cashier.Utils.hexStringToByteArray
-import org.json.JSONObject
-import java.io.ByteArrayOutputStream
-import java.net.URL
-import javax.net.ssl.HttpsURLConnection
-
-@Suppress("unused")
-private const val TALER_AID = "A0000002471001"
-
-class NfcManager : NfcAdapter.ReaderCallback {
-
-    companion object {
-        const val TAG = "taler-merchant"
-
-        /**
-         * Returns true if NFC is supported and false otherwise.
-         */
-        fun hasNfc(context: Context): Boolean {
-            return getNfcAdapter(context) != null
-        }
-
-        /**
-         * Enables NFC reader mode. Don't forget to call [stop] afterwards.
-         */
-        fun start(activity: Activity, nfcManager: NfcManager) {
-            getNfcAdapter(activity)?.enableReaderMode(activity, nfcManager, nfcManager.flags, null)
-        }
-
-        /**
-         * Disables NFC reader mode. Call after [start].
-         */
-        fun stop(activity: Activity) {
-            getNfcAdapter(activity)?.disableReaderMode(activity)
-        }
-
-        private fun getNfcAdapter(context: Context): NfcAdapter? {
-            return getDefaultAdapter(context)
-        }
-    }
-
-    private val flags = FLAG_READER_NFC_A or FLAG_READER_SKIP_NDEF_CHECK
-
-    private var tagString: String? = null
-    private var currentTag: IsoDep? = null
-
-    fun setTagString(tagString: String) {
-        this.tagString = tagString
-    }
-
-    override fun onTagDiscovered(tag: Tag?) {
-
-        Log.v(TAG, "tag discovered")
-
-        val isoDep = IsoDep.get(tag)
-        isoDep.connect()
-
-        currentTag = isoDep
-
-        isoDep.transceive(apduSelectFile())
-
-        val tagString: String? = tagString
-        if (tagString != null) {
-            isoDep.transceive(apduPutTalerData(1, tagString.toByteArray()))
-        }
-
-        // FIXME: use better pattern for sleeps in between requests
-        // -> start with fast polling, poll more slowly if no requests are coming
-
-        while (true) {
-            try {
-                val reqFrame = isoDep.transceive(apduGetData())
-                if (reqFrame.size < 2) {
-                    Log.v(TAG, "request frame too small")
-                    break
-                }
-                val req = ByteArray(reqFrame.size - 2)
-                if (req.isEmpty()) {
-                    continue
-                }
-                reqFrame.copyInto(req, 0, 0, reqFrame.size - 2)
-                val jsonReq = JSONObject(req.toString(Charsets.UTF_8))
-                val reqId = jsonReq.getInt("id")
-                Log.v(TAG, "got request $jsonReq")
-                val jsonInnerReq = jsonReq.getJSONObject("request")
-                val method = jsonInnerReq.getString("method")
-                val urlStr = jsonInnerReq.getString("url")
-                Log.v(TAG, "url '$urlStr'")
-                Log.v(TAG, "method '$method'")
-                val url = URL(urlStr)
-                val conn: HttpsURLConnection = url.openConnection() as HttpsURLConnection
-                conn.setRequestProperty("Accept", "application/json")
-                conn.connectTimeout = 5000
-                conn.doInput = true
-                when (method) {
-                    "get" -> {
-                        conn.requestMethod = "GET"
-                    }
-                    "postJson" -> {
-                        conn.requestMethod = "POST"
-                        conn.doOutput = true
-                        conn.setRequestProperty("Content-Type", "application/json; utf-8")
-                        val body = jsonInnerReq.getString("body")
-                        conn.outputStream.write(body.toByteArray(Charsets.UTF_8))
-                    }
-                    else -> {
-                        throw Exception("method not supported")
-                    }
-                }
-                Log.v(TAG, "connecting")
-                conn.connect()
-                Log.v(TAG, "connected")
-
-                val statusCode = conn.responseCode
-                val tunnelResp = JSONObject()
-                tunnelResp.put("id", reqId)
-                tunnelResp.put("status", conn.responseCode)
-
-                if (statusCode == 200) {
-                    val stream = conn.inputStream
-                    val httpResp = stream.buffered().readBytes()
-                    tunnelResp.put("responseJson", JSONObject(httpResp.toString(Charsets.UTF_8)))
-                }
-
-                Log.v(TAG, "sending: $tunnelResp")
-
-                isoDep.transceive(apduPutTalerData(2, tunnelResp.toString().toByteArray()))
-            } catch (e: Exception) {
-                Log.v(TAG, "exception during NFC loop: $e")
-                break
-            }
-        }
-
-        isoDep.close()
-    }
-
-    private fun writeApduLength(stream: ByteArrayOutputStream, size: Int) {
-        when {
-            size == 0 -> {
-                // No size field needed!
-            }
-            size <= 255 -> // One byte size field
-                stream.write(size)
-            size <= 65535 -> {
-                stream.write(0)
-                // FIXME: is this supposed to be little or big endian?
-                stream.write(size and 0xFF)
-                stream.write((size ushr 8) and 0xFF)
-            }
-            else -> throw Error("payload too big")
-        }
-    }
-
-    private fun apduSelectFile(): ByteArray {
-        return hexStringToByteArray("00A4040007A0000002471001")
-    }
-
-    private fun apduPutData(payload: ByteArray): ByteArray {
-        val stream = ByteArrayOutputStream()
-
-        // Class
-        stream.write(0x00)
-
-        // Instruction 0xDA = put data
-        stream.write(0xDA)
-
-        // Instruction parameters
-        // (proprietary encoding)
-        stream.write(0x01)
-        stream.write(0x00)
-
-        writeApduLength(stream, payload.size)
-
-        stream.write(payload)
-
-        return stream.toByteArray()
-    }
-
-    private fun apduPutTalerData(talerInst: Int, payload: ByteArray): ByteArray {
-        val realPayload = ByteArrayOutputStream()
-        realPayload.write(talerInst)
-        realPayload.write(payload)
-        return apduPutData(realPayload.toByteArray())
-    }
-
-    private fun apduGetData(): ByteArray {
-        val stream = ByteArrayOutputStream()
-
-        // Class
-        stream.write(0x00)
-
-        // Instruction 0xCA = get data
-        stream.write(0xCA)
-
-        // Instruction parameters
-        // (proprietary encoding)
-        stream.write(0x01)
-        stream.write(0x00)
-
-        // Max expected response size, two
-        // zero bytes denotes 65536
-        stream.write(0x0)
-        stream.write(0x0)
-
-        return stream.toByteArray()
-    }
-
-}
diff --git a/cashier/src/main/java/net/taler/cashier/withdraw/QrCodeManager.kt b/cashier/src/main/java/net/taler/cashier/withdraw/QrCodeManager.kt
deleted file mode 100644
index e3ffa92..0000000
--- a/cashier/src/main/java/net/taler/cashier/withdraw/QrCodeManager.kt
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * This file is part of GNU Taler
- * (C) 2020 Taler Systems S.A.
- *
- * GNU Taler is free software; you can redistribute it and/or modify it under the
- * terms of the GNU General Public License as published by the Free Software
- * Foundation; either version 3, or (at your option) any later version.
- *
- * GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
- * A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
- */
-
-package net.taler.cashier.withdraw
-
-import android.graphics.Bitmap
-import android.graphics.Bitmap.Config.RGB_565
-import android.graphics.Color.BLACK
-import android.graphics.Color.WHITE
-import com.google.zxing.BarcodeFormat.QR_CODE
-import com.google.zxing.qrcode.QRCodeWriter
-
-object QrCodeManager {
-
-    fun makeQrCode(text: String, size: Int = 256): Bitmap {
-        val qrCodeWriter = QRCodeWriter()
-        val bitMatrix = qrCodeWriter.encode(text, QR_CODE, size, size)
-        val height = bitMatrix.height
-        val width = bitMatrix.width
-        val bmp = Bitmap.createBitmap(width, height, RGB_565)
-        for (x in 0 until width) {
-            for (y in 0 until height) {
-                bmp.setPixel(x, y, if (bitMatrix.get(x, y)) BLACK else WHITE)
-            }
-        }
-        return bmp
-    }
-
-}
diff --git a/cashier/src/main/java/net/taler/cashier/withdraw/TransactionFragment.kt b/cashier/src/main/java/net/taler/cashier/withdraw/TransactionFragment.kt
index 8b782b0..8857bfa 100644
--- a/cashier/src/main/java/net/taler/cashier/withdraw/TransactionFragment.kt
+++ b/cashier/src/main/java/net/taler/cashier/withdraw/TransactionFragment.kt
@@ -30,13 +30,14 @@ import androidx.navigation.fragment.findNavController
 import kotlinx.android.synthetic.main.fragment_transaction.*
 import net.taler.cashier.MainViewModel
 import net.taler.cashier.R
-import net.taler.cashier.fadeIn
-import net.taler.cashier.fadeOut
 import net.taler.cashier.withdraw.TransactionFragmentDirections.Companion.actionTransactionFragmentToBalanceFragment
 import net.taler.cashier.withdraw.TransactionFragmentDirections.Companion.actionTransactionFragmentToErrorFragment
 import net.taler.cashier.withdraw.WithdrawResult.Error
 import net.taler.cashier.withdraw.WithdrawResult.InsufficientBalance
 import net.taler.cashier.withdraw.WithdrawResult.Success
+import net.taler.common.NfcManager
+import net.taler.common.fadeIn
+import net.taler.common.fadeOut
 
 class TransactionFragment : Fragment() {
 
diff --git a/cashier/src/main/java/net/taler/cashier/withdraw/WithdrawManager.kt b/cashier/src/main/java/net/taler/cashier/withdraw/WithdrawManager.kt
index 4c618ac..bfc82ce 100644
--- a/cashier/src/main/java/net/taler/cashier/withdraw/WithdrawManager.kt
+++ b/cashier/src/main/java/net/taler/cashier/withdraw/WithdrawManager.kt
@@ -34,6 +34,7 @@ import net.taler.cashier.HttpJsonResult.Error
 import net.taler.cashier.HttpJsonResult.Success
 import net.taler.cashier.MainViewModel
 import net.taler.cashier.R
+import net.taler.common.QrCodeManager.makeQrCode
 import org.json.JSONObject
 import java.util.concurrent.TimeUnit.MINUTES
 import java.util.concurrent.TimeUnit.SECONDS
@@ -95,7 +96,7 @@ class WithdrawManager(
                     val withdrawResult = WithdrawResult.Success(
                         id = result.json.getString("withdrawal_id"),
                         talerUri = talerUri,
-                        qrCode = QrCodeManager.makeQrCode(talerUri)
+                        qrCode = makeQrCode(talerUri)
                     )
                     mWithdrawResult.postValue(withdrawResult)
                     timer.start()