feat(labs): CryptographicAgeVerificationSandbox

Signed-off-by: Infi <infi@infi.sh>

app/src/main/java/chat/revolt/internals/CryptographicAgeVerification.kt

@@ -0,0 +1,41 @@
+package chat.revolt.internals
+
+import java.security.MessageDigest
+
+class CryptographicAgeVerification {
+    fun getProofHash(
+        seed: String,
+        userAge: Int,
+        minAllowedAge: Int
+    ): Pair<ByteArray, ByteArray> {
+        var proof = MessageDigest.getInstance("SHA-256").digest(seed.toByteArray())
+
+        for (i in 1 until userAge - minAllowedAge) {
+            proof = MessageDigest.getInstance("SHA-256").digest(proof)
+        }
+
+        var ageHash =
+            MessageDigest.getInstance("SHA-256").digest(seed.toByteArray())
+
+        for (i in 1 until userAge - 1) {
+            ageHash = MessageDigest.getInstance("SHA-256").digest(ageHash)
+        }
+
+        return ageHash to proof
+    }
+
+    fun proveAge(
+        minAllowedAge: Int,
+        proofHash: ByteArray,
+        ageHash: ByteArray,
+    ): Boolean {
+        var verifyHash =
+            MessageDigest.getInstance("SHA-256").digest(proofHash.toString().toByteArray())
+
+        for (i in 1 until minAllowedAge - 1) {
+            verifyHash = MessageDigest.getInstance("SHA-256").digest(verifyHash)
+        }
+
+        return verifyHash.contentEquals(ageHash)
+    }
+}

app/src/main/java/chat/revolt/screens/labs/LabsHomeScreen.kt

@@ -13,6 +13,7 @@ import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Home
 import androidx.compose.material.icons.filled.Menu
+import androidx.compose.material.icons.filled.PlayArrow
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
@@ -36,6 +37,7 @@ import androidx.navigation.NavController
 enum class LabsHomeScreenTab {
     Home,
     Mockups,
+    Sandboxes,
 }
 
 @OptIn(ExperimentalMaterial3Api::class)
@@ -80,6 +82,19 @@ fun LabsHomeScreen(navController: NavController) {
                         Text("UI Mockups")
                     }
                 )
+                NavigationBarItem(
+                    selected = currentTab.value == LabsHomeScreenTab.Sandboxes,
+                    onClick = { currentTab.value = LabsHomeScreenTab.Sandboxes },
+                    icon = {
+                        Icon(
+                            imageVector = Icons.Default.PlayArrow,
+                            contentDescription = null,
+                        )
+                    },
+                    label = {
+                        Text("Sandboxes")
+                    }
+                )
             }
         }
     ) {
@@ -128,6 +143,22 @@ fun LabsHomeScreen(navController: NavController) {
                         HorizontalDivider()
                     }
                 }
+
+                LabsHomeScreenTab.Sandboxes -> {
+                    Column(
+                        modifier = Modifier.verticalScroll(rememberScrollState())
+                    ) {
+                        ListItem(
+                            headlineContent = {
+                                Text("Cryptographic Age Verification")
+                            },
+                            modifier = Modifier.clickable {
+                                navController.navigate("sandboxes/cryptoageverif")
+                            }
+                        )
+                        HorizontalDivider()
+                    }
+                }
             }
         }
     }

app/src/main/java/chat/revolt/screens/labs/LabsRootScreen.kt

@@ -13,6 +13,7 @@ import androidx.navigation.compose.composable
 import androidx.navigation.compose.rememberNavController
 import chat.revolt.api.settings.FeatureFlags
 import chat.revolt.screens.labs.ui.mockups.CallScreenMockup
+import chat.revolt.screens.labs.ui.sandbox.CryptographicAgeVerificationSandbox
 
 annotation class LabsFeature
 
@@ -62,6 +63,10 @@ fun LabsRootScreen(topNav: NavController) {
                 composable("mockups/call") {
                     CallScreenMockup()
                 }
+
+                composable("sandboxes/cryptoageverif") {
+                    CryptographicAgeVerificationSandbox(labsNav)
+                }
             }
         }
     }

app/src/main/java/chat/revolt/screens/labs/ui/sandbox/CryptographicAgeVerificationSandbox.kt

@@ -0,0 +1,78 @@
+package chat.revolt.screens.labs.ui.sandbox
+
+import android.util.Log
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material3.Button
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.navigation.NavController
+import chat.revolt.api.REVOLT_KJBOOK
+import chat.revolt.internals.CryptographicAgeVerification
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun CryptographicAgeVerificationSandbox(navController: NavController) {
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = {
+                    Text(
+                        "Crypto Age Verify Sandbox",
+                        maxLines = 1,
+                        overflow = TextOverflow.Ellipsis
+                    )
+                },
+                navigationIcon = {
+                    IconButton(onClick = { navController.popBackStack() }) {
+                        Icon(Icons.AutoMirrored.Default.ArrowBack, "Back")
+                    }
+                }
+            )
+        }
+    ) { pv ->
+        Column(
+            Modifier
+                .padding(pv)
+                .fillMaxSize()
+        ) {
+            Button(onClick = {
+                val cav = CryptographicAgeVerification()
+                val (ageHash, verifyHash) = cav.getProofHash(
+                    seed = REVOLT_KJBOOK,
+                    userAge = 21,
+                    minAllowedAge = 18
+                )
+
+                Log.d(
+                    "CryptographicAgeVerificationSandbox",
+                    "ageHash: ${ageHash.contentToString()}"
+                )
+                Log.d(
+                    "CryptographicAgeVerificationSandbox",
+                    "verifyHash: ${verifyHash.contentToString()}"
+                )
+
+                val verification = cav.proveAge(
+                    minAllowedAge = 18,
+                    proofHash = verifyHash,
+                    ageHash = ageHash
+                )
+
+                Log.d("CryptographicAgeVerificationSandbox", "Verification result: $verification")
+            }) {
+                Text("Run Cryptographic Age Verification")
+            }
+        }
+    }
+}