Moving the NIP98 event to it's own class.

app/src/main/java/com/vitorpamplona/amethyst/model/Account.kt

@@ -24,6 +24,7 @@ import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 import nostr.postr.Persona
 import nostr.postr.Utils
+import retrofit2.http.HTTP
 import java.math.BigDecimal
 import java.net.Proxy
 import java.util.Locale
@@ -322,6 +323,12 @@ class Account(
         }
     }
 
+    fun createHTTPAuthorization(url: String, method: String, body: String? = null): HTTPAuthorizationEvent? {
+        if (!isWriteable()) return null
+
+        return HTTPAuthorizationEvent.create(url, method, body, loggedIn.privKey!!)
+    }
+
     fun boost(note: Note) {
         if (!isWriteable()) return
 

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

@@ -0,0 +1,49 @@
+package com.vitorpamplona.amethyst.service.model
+
+import androidx.compose.runtime.Immutable
+import com.vitorpamplona.amethyst.model.HexKey
+import com.vitorpamplona.amethyst.model.toHexKey
+import nostr.postr.Utils
+import java.security.MessageDigest
+import java.util.Date
+
+@Immutable
+class HTTPAuthorizationEvent(
+    id: HexKey,
+    pubKey: HexKey,
+    createdAt: Long,
+    tags: List<List<String>>,
+    content: String,
+    sig: HexKey
+) : Event(id, pubKey, createdAt, kind, tags, content, sig) {
+
+    companion object {
+        const val kind = 27235
+
+        fun create(
+            url: String,
+            method: String,
+            body: String? = null,
+            privateKey: ByteArray,
+            createdAt: Long = Date().time / 1000
+        ): HTTPAuthorizationEvent {
+            val sha256 = MessageDigest.getInstance("SHA-256")
+
+            var hash = ""
+            body?.let {
+                hash = sha256.digest(it.toByteArray()).toHexKey()
+            }
+
+            val tags = listOfNotNull(
+                listOf("u", url),
+                listOf("method", method),
+                listOf("payload", hash)
+            )
+
+            val pubKey = Utils.pubkeyCreate(privateKey).toHexKey()
+            val id = generateId(pubKey, createdAt, kind, tags, "")
+            val sig = Utils.sign(id, privateKey)
+            return HTTPAuthorizationEvent(id.toHexKey(), pubKey, createdAt, tags, "", sig.toHexKey())
+        }
+    }
+}

app/src/main/java/com/vitorpamplona/amethyst/ui/actions/ImageUploader.kt

@@ -11,6 +11,7 @@ import com.vitorpamplona.amethyst.model.Account
 import com.vitorpamplona.amethyst.model.toHexKey
 import com.vitorpamplona.amethyst.service.HttpClient
 import com.vitorpamplona.amethyst.service.model.Event
+import com.vitorpamplona.amethyst.service.model.HTTPAuthorizationEvent
 import okhttp3.*
 import okhttp3.MediaType.Companion.toMediaType
 import okio.BufferedSink
@@ -142,13 +143,7 @@ object ImageUploader {
     }
 
     fun NIP98Header(url: String, method: String, body: String): String {
-        var hash = ""
+        val noteJson = account.createHTTPAuthorization(url, method, body)?.toJson() ?: ""
-        if (body != "") {
-            val sha256 = MessageDigest.getInstance("SHA-256")
-            hash = sha256.digest(body.toByteArray()).toHexKey()
-        }
-        var tags = listOf(listOf("u", url), listOf("method", method), listOf("payload", hash))
-        var noteJson = (Event.create(account.loggedIn.privKey!!, 27235, tags, "")).toJson()
         val encodedNIP98Event: String = Base64.getEncoder().encodeToString(noteJson.toByteArray())
         return "Nostr " + encodedNIP98Event
     }