Identities: let the user specify a subject CN

app/src/main/java/dev/lowrespalmtree/comet/Identities.kt

@@ -4,8 +4,10 @@ import android.security.keystore.KeyGenParameterSpec
 import android.security.keystore.KeyProperties
 import android.util.Log
 import androidx.room.*
+import java.lang.IllegalArgumentException
 import java.security.KeyPairGenerator
 import java.security.KeyStore
+import javax.security.auth.x500.X500Principal
 
 object Identities {
     @Entity
@@ -58,11 +60,20 @@ object Identities {
         Database.INSTANCE.identityDao().delete(*identities)
     }
 
-    fun generateClientCert(alias: String) {
+    fun generateClientCert(alias: String, commonName: String) {
         val algo = KeyProperties.KEY_ALGORITHM_RSA
         val kpg = KeyPairGenerator.getInstance(algo, "AndroidKeyStore")
         val purposes = KeyProperties.PURPOSE_SIGN or KeyProperties.PURPOSE_VERIFY
         val spec = KeyGenParameterSpec.Builder(alias, purposes)
+            .apply {
+                if (commonName.isNotEmpty()) {
+                    try {
+                        setCertificateSubject(X500Principal("CN=$commonName"))
+                    } catch (e: IllegalArgumentException) {
+                        Log.e(TAG, "generateClientCert: bad common name: ${e.message}")
+                    }
+                }
+            }
             .setDigests(KeyProperties.DIGEST_SHA256)
             .build()
         kpg.initialize(spec)

app/src/main/java/dev/lowrespalmtree/comet/IdentitiesFragment.kt

@@ -82,27 +82,39 @@ class IdentitiesFragment : Fragment(), IdentitiesAdapter.Listener, IdentityEditD
         vm.saveIdentity(identity)
     }
 
-    private fun openNewIdentityEditor() {
-        toast(requireContext(), R.string.generating_keypair)
-        vm.newIdentity.observe(viewLifecycleOwner) { identity ->
-            if (identity == null)
-                return@observe
-            vm.newIdentity.removeObservers(viewLifecycleOwner)
-            vm.newIdentity.value = null
-            IdentityDialog(requireContext(), identity, this).show()
-        }
-        vm.createNewIdentity()
+    /**
+     * Open the new identity wizard.
+     *
+     * There is a first dialog to ask the user about the desired subject common name,
+     * then the certificate is generated and the edition dialog is opened.
+     */
+    private fun openIdentityWizard() {
+        InputDialog(requireContext(), getString(R.string.input_common_name))
+            .show(
+                onOk = { text ->
+                    toast(requireContext(), R.string.generating_keypair)
+                    vm.newIdentity.observe(viewLifecycleOwner) { identity ->
+                        if (identity == null)
+                            return@observe
+                        vm.newIdentity.removeObservers(viewLifecycleOwner)
+                        vm.newIdentity.value = null
+                        IdentityEditDialog(requireContext(), identity, this).show()
+                    }
+                    vm.createNewIdentity(text)
+                },
+                onDismiss = {}
+            )
     }
 
     class IdentitiesViewModel : ViewModel() {
         val identities: MutableLiveData<List<Identity>> by lazy { MutableLiveData<List<Identity>>() }
         val newIdentity: MutableLiveData<Identity> by lazy { MutableLiveData<Identity>() }
 
-        fun createNewIdentity() {
+        fun createNewIdentity(commonName: String) {
             viewModelScope.launch(Dispatchers.IO) {
                 val alias = "identity-${UUID.randomUUID()}"
-                Identities.generateClientCert(alias)
-                val newIdentityId = Identities.insert(alias)
+                Identities.generateClientCert(alias, commonName)
+                val newIdentityId = Identities.insert(alias, commonName)
                 newIdentity.postValue(Identities.get(newIdentityId))
             }
                 .invokeOnCompletion { refreshIdentities() }

app/src/main/res/values/strings.xml

@@ -44,6 +44,7 @@
     <string name="confirm">Confirm</string>
     <string name="confirm_identity_delete">Are you sure you want to delete this identity? The client certificate cannot be retrieved afterwards.</string>
     <string name="edit">Edit</string>
-    <string name="identity_usages">Active URL paths</string>
+    <string name="identity_usages">Active URL path</string>
+    <string name="input_common_name">Enter a name to use as the certificate\'s subject common name. This can be left empty.</string>
 
 </resources>