Refactoring dependency path to center in CryptoUtils

app/src/main/java/com/vitorpamplona/amethyst/service/Bech32Util.kt

@@ -22,7 +22,7 @@ import kotlin.jvm.JvmStatic
  * Bech32 works with 5 bits values, we use this type to make it explicit: whenever you see Int5 it means 5 bits values,
  * and whenever you see Byte it means 8 bits values.
  */
-public typealias Int5 = Byte
+private typealias Int5 = Byte
 
 /**
  * Bech32 and Bech32m address formats.

app/src/main/java/com/vitorpamplona/amethyst/service/CryptoUtils.kt

@@ -2,6 +2,7 @@ package com.vitorpamplona.amethyst.service
 
 import fr.acinq.secp256k1.Hex
 import fr.acinq.secp256k1.Secp256k1
+import java.security.MessageDigest
 import java.security.SecureRandom
 import java.util.Base64
 import javax.crypto.Cipher
@@ -9,6 +10,9 @@ import javax.crypto.spec.IvParameterSpec
 import javax.crypto.spec.SecretKeySpec
 
 object CryptoUtils {
+    private val secp256k1 = Secp256k1.get()
+    private val random = SecureRandom()
+
     /**
      * Provides a 32B "private key" aka random number
      */
@@ -54,15 +58,24 @@ object CryptoUtils {
         return String(cipher.doFinal(encryptedMsg))
     }
 
+    fun verifySignature(
+        signature: ByteArray,
+        hash: ByteArray,
+        pubKey: ByteArray
+    ): Boolean {
+        return secp256k1.verifySchnorr(signature, hash, pubKey)
+    }
+
+    fun sha256(data: ByteArray): ByteArray {
+        // Creates a new buffer every time
+        return MessageDigest.getInstance("SHA-256").digest(data)
+    }
+
     /**
      * @return 32B shared secret
      */
     fun getSharedSecret(privateKey: ByteArray, pubKey: ByteArray): ByteArray =
         secp256k1.pubKeyTweakMul(Hex.decode("02") + pubKey, privateKey).copyOfRange(1, 33)
-
-    private val secp256k1 = Secp256k1.get()
-
-    private val random = SecureRandom()
 }
 
 fun Int.toByteArray(): ByteArray {

app/src/main/java/com/vitorpamplona/amethyst/service/FileHeader.kt

@@ -6,7 +6,6 @@ import android.util.Log
 import com.vitorpamplona.amethyst.model.toHexKey
 import com.vitorpamplona.amethyst.ui.actions.ImageDownloader
 import io.trbl.blurhash.BlurHash
-import java.security.MessageDigest
 import kotlin.math.roundToInt
 
 class FileHeader(
@@ -45,9 +44,7 @@ class FileHeader(
             onError: () -> Unit
         ) {
             try {
-                val sha256 = MessageDigest.getInstance("SHA-256")
+                val hash = CryptoUtils.sha256(data).toHexKey()
-
-                val hash = sha256.digest(data).toHexKey()
                 val size = data.size
 
                 val (blurHash, dim) = if (mimeType?.startsWith("image/") == true) {

app/src/main/java/com/vitorpamplona/amethyst/service/model/Event.kt

@@ -13,7 +13,6 @@ import fr.acinq.secp256k1.Hex
 import fr.acinq.secp256k1.Secp256k1
 import java.lang.reflect.Type
 import java.math.BigDecimal
-import java.security.MessageDigest
 import java.util.*
 
 @Immutable
@@ -157,14 +156,14 @@ open class Event(
                 """.trimIndent()
             )
         }
-        if (!secp256k1.verifySchnorr(Hex.decode(sig), Hex.decode(id), Hex.decode(pubKey))) {
+        if (!CryptoUtils.verifySignature(Hex.decode(sig), Hex.decode(id), Hex.decode(pubKey))) {
             throw Exception("""Bad signature!""")
         }
     }
 
     override fun hasValidSignature(): Boolean {
         return try {
-            id.contentEquals(generateId()) && secp256k1.verifySchnorr(Hex.decode(sig), Hex.decode(id), Hex.decode(pubKey))
+            id.contentEquals(generateId()) && CryptoUtils.verifySignature(Hex.decode(sig), Hex.decode(id), Hex.decode(pubKey))
         } catch (e: Exception) {
             Log.e("Event", "Fail checking if event $id has a valid signature", e)
             false
@@ -182,7 +181,7 @@ open class Event(
             .replace("\\u2028", "\u2028")
             .replace("\\u2029", "\u2029")
 
-        return MessageDigest.getInstance("SHA-256").digest(rawEventJson.toByteArray()).toHexKey()
+        return CryptoUtils.sha256(rawEventJson.toByteArray()).toHexKey()
     }
 
     private class EventDeserializer : JsonDeserializer<Event> {
@@ -336,7 +335,7 @@ open class Event(
                 .replace("\\u2028", "\u2028")
                 .replace("\\u2029", "\u2029")
 
-            return MessageDigest.getInstance("SHA-256").digest(rawEventJson.toByteArray())
+            return CryptoUtils.sha256(rawEventJson.toByteArray())
         }
 
         fun create(privateKey: ByteArray, kind: Int, tags: List<List<String>> = emptyList(), content: String = "", createdAt: Long = TimeUtils.now()): Event {

app/src/main/java/com/vitorpamplona/amethyst/service/model/HTTPAuthorizationEvent.kt

@@ -5,7 +5,6 @@ import com.vitorpamplona.amethyst.model.HexKey
 import com.vitorpamplona.amethyst.model.TimeUtils
 import com.vitorpamplona.amethyst.model.toHexKey
 import com.vitorpamplona.amethyst.service.CryptoUtils
-import java.security.MessageDigest
 
 @Immutable
 class HTTPAuthorizationEvent(
@@ -27,11 +26,9 @@ class HTTPAuthorizationEvent(
             privateKey: ByteArray,
             createdAt: Long = TimeUtils.now()
         ): HTTPAuthorizationEvent {
-            val sha256 = MessageDigest.getInstance("SHA-256")
-
             var hash = ""
             body?.let {
-                hash = sha256.digest(it.toByteArray()).toHexKey()
+                hash = CryptoUtils.sha256(it.toByteArray()).toHexKey()
             }
 
             val tags = listOfNotNull(

app/src/main/java/com/vitorpamplona/amethyst/service/model/LnZapRequestEvent.kt

@@ -5,7 +5,6 @@ import com.vitorpamplona.amethyst.model.*
 import com.vitorpamplona.amethyst.service.Bech32
 import com.vitorpamplona.amethyst.service.CryptoUtils
 import java.nio.charset.Charset
-import java.security.MessageDigest
 import java.security.SecureRandom
 import javax.crypto.BadPaddingException
 import javax.crypto.Cipher
@@ -133,7 +132,7 @@ class LnZapRequestEvent(
         fun createEncryptionPrivateKey(privkey: String, id: String, createdAt: Long): ByteArray {
             var str = privkey + id + createdAt.toString()
             var strbyte = str.toByteArray(Charset.forName("utf-8"))
-            return MessageDigest.getInstance("SHA-256").digest(strbyte)
+            return CryptoUtils.sha256(strbyte)
         }
 
         private fun encryptPrivateZapMessage(msg: String, privkey: ByteArray, pubkey: ByteArray): String {

app/src/main/java/com/vitorpamplona/amethyst/ui/components/Robohash.kt

@@ -13,9 +13,9 @@ import coil.fetch.Fetcher
 import coil.fetch.SourceResult
 import coil.request.ImageRequest
 import coil.request.Options
+import com.vitorpamplona.amethyst.service.CryptoUtils
 import com.vitorpamplona.amethyst.service.checkNotInMainThread
 import okio.Buffer
-import java.security.MessageDigest
 
 private fun toHex(color: Color): String {
     val argb = color.toArgb()
@@ -35,7 +35,7 @@ private fun bytesToRGB(b1: Byte, b2: Byte, b3: Byte): Color {
 private fun svgString(msg: String): String {
     checkNotInMainThread()
 
-    val hash = MessageDigest.getInstance("SHA-256").digest(msg.toByteArray())
+    val hash = CryptoUtils.sha256(msg.toByteArray())
     val hashHex = hash.joinToString(separator = "") { b -> "%02x".format(b) }
     val bgColor = bytesToRGB(hash[0], hash[1], hash[2])
     val fgColor = bytesToRGB(hash[3], hash[4], hash[5])

app/src/main/java/com/vitorpamplona/amethyst/ui/components/ZoomableContentView.kt

@@ -69,6 +69,7 @@ import com.vitorpamplona.amethyst.R
 import com.vitorpamplona.amethyst.model.ConnectivityType
 import com.vitorpamplona.amethyst.model.toHexKey
 import com.vitorpamplona.amethyst.service.BlurHashRequester
+import com.vitorpamplona.amethyst.service.CryptoUtils
 import com.vitorpamplona.amethyst.service.connectivitystatus.ConnectivityStatus
 import com.vitorpamplona.amethyst.ui.actions.CloseButton
 import com.vitorpamplona.amethyst.ui.actions.LoadingAnimation
@@ -91,7 +92,6 @@ import kotlinx.coroutines.launch
 import net.engawapg.lib.zoomable.rememberZoomState
 import net.engawapg.lib.zoomable.zoomable
 import java.io.File
-import java.security.MessageDigest
 
 @Immutable
 abstract class ZoomableContent(
@@ -697,11 +697,7 @@ private fun verifyHash(content: ZoomableUrlContent, context: Context): Boolean?
     if (content.hash == null) return null
 
     context.imageLoader.diskCache?.get(content.url)?.use { snapshot ->
-        val imageFile = snapshot.data.toFile()
+        val hash = CryptoUtils.sha256(snapshot.data.toFile().readBytes()).toHexKey()
-        val bytes = imageFile.readBytes()
-        val sha256 = MessageDigest.getInstance("SHA-256")
-
-        val hash = sha256.digest(bytes).toHexKey()
 
         Log.d("Image Hash Verification", "$hash == ${content.hash}")