Implement support for `.gpg-id` (#2080)

7 files changed, 90 insertions, 32 deletions

diff --git a/app/src/main/java/app/passwordstore/data/crypto/CryptoRepository.kt b/app/src/main/java/app/passwordstore/data/crypto/CryptoRepository.kt
index 6c214fd1..297ada95 100644
--- a/app/src/main/java/app/passwordstore/data/crypto/CryptoRepository.kt
+++ b/app/src/main/java/app/passwordstore/data/crypto/CryptoRepository.kt
@@ -5,9 +5,10 @@
 
 package app.passwordstore.data.crypto
 
+import app.passwordstore.crypto.GpgIdentifier
 import app.passwordstore.crypto.PGPKeyManager
 import app.passwordstore.crypto.PGPainlessCryptoHandler
-import app.passwordstore.util.extensions.isOk
+import com.github.michaelbull.result.getAll
 import com.github.michaelbull.result.unwrap
 import java.io.ByteArrayInputStream
 import java.io.ByteArrayOutputStream
@@ -30,8 +31,12 @@ constructor(
     withContext(Dispatchers.IO) { decryptPgp(password, message, out) }
   }
 
-  suspend fun encrypt(content: ByteArrayInputStream, out: ByteArrayOutputStream) {
-    withContext(Dispatchers.IO) { encryptPgp(content, out) }
+  suspend fun encrypt(
+    identities: List<GpgIdentifier>,
+    content: ByteArrayInputStream,
+    out: ByteArrayOutputStream,
+  ) {
+    withContext(Dispatchers.IO) { encryptPgp(identities, content, out) }
   }
 
   private suspend fun decryptPgp(
@@ -41,11 +46,15 @@ constructor(
   ) {
     val keys = pgpKeyManager.getAllKeys().unwrap()
     // Iterates through the keys until the first successful decryption, then returns.
-    keys.firstOrNull { key -> pgpCryptoHandler.decrypt(key, password, message, out).isOk() }
+    pgpCryptoHandler.decrypt(keys, password, message, out)
   }
 
-  private suspend fun encryptPgp(content: ByteArrayInputStream, out: ByteArrayOutputStream) {
-    val keys = pgpKeyManager.getAllKeys().unwrap()
+  private suspend fun encryptPgp(
+    identities: List<GpgIdentifier>,
+    content: ByteArrayInputStream,
+    out: ByteArrayOutputStream,
+  ) {
+    val keys = identities.map { ident -> pgpKeyManager.getKeyById(ident) }.getAll()
     pgpCryptoHandler.encrypt(
       keys,
       content,
diff --git a/app/src/main/java/app/passwordstore/ui/crypto/DecryptActivity.kt b/app/src/main/java/app/passwordstore/ui/crypto/DecryptActivity.kt
index 3fb0d52f..fa37f501 100644
--- a/app/src/main/java/app/passwordstore/ui/crypto/DecryptActivity.kt
+++ b/app/src/main/java/app/passwordstore/ui/crypto/DecryptActivity.kt
@@ -21,6 +21,7 @@ import app.passwordstore.util.extensions.unsafeLazy
 import app.passwordstore.util.extensions.viewBinding
 import app.passwordstore.util.settings.PreferenceKeys
 import com.github.michaelbull.result.runCatching
+import com.github.michaelbull.result.unwrapError
 import dagger.hilt.android.AndroidEntryPoint
 import java.io.ByteArrayOutputStream
 import java.io.File
@@ -35,6 +36,8 @@ import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
+import logcat.LogPriority.ERROR
+import logcat.logcat
 
 @OptIn(ExperimentalTime::class)
 @AndroidEntryPoint
@@ -140,7 +143,9 @@ class DecryptActivity : BasePgpActivity() {
     lifecycleScope.launch(Dispatchers.Main) {
       dialog.password.collectLatest { value ->
         if (value != null) {
-          if (runCatching { decrypt(value) }.isErr()) {
+          val res = runCatching { decrypt(value) }
+          if (res.isErr()) {
+            logcat(ERROR) { res.unwrapError().stackTraceToString() }
             decrypt(isError = true)
           }
         }
@@ -161,7 +166,6 @@ class DecryptActivity : BasePgpActivity() {
         )
         outputStream
       }
-    require(result.size() != 0) { "Incorrect password" }
     startAutoDismissTimer()
 
     val entry = passwordEntryFactory.create(result.toByteArray())
diff --git a/app/src/main/java/app/passwordstore/ui/crypto/PasswordCreationActivity.kt b/app/src/main/java/app/passwordstore/ui/crypto/PasswordCreationActivity.kt
index 2e3e48a9..fddc2943 100644
--- a/app/src/main/java/app/passwordstore/ui/crypto/PasswordCreationActivity.kt
+++ b/app/src/main/java/app/passwordstore/ui/crypto/PasswordCreationActivity.kt
@@ -24,8 +24,10 @@ import androidx.core.view.isVisible
 import androidx.core.widget.doAfterTextChanged
 import androidx.lifecycle.lifecycleScope
 import app.passwordstore.R
+import app.passwordstore.crypto.GpgIdentifier
 import app.passwordstore.data.crypto.CryptoRepository
 import app.passwordstore.data.passfile.PasswordEntry
+import app.passwordstore.data.repo.PasswordRepository
 import app.passwordstore.databinding.PasswordCreationActivityBinding
 import app.passwordstore.ui.dialogs.DicewarePasswordGeneratorDialogFragment
 import app.passwordstore.ui.dialogs.OtpImportDialogFragment
@@ -332,6 +334,32 @@ class PasswordCreationActivity : BasePgpActivity() {
         copyPasswordToClipboard(editPass)
       }
 
+      // pass enters the key ID into `.gpg-id`.
+      val repoRoot = PasswordRepository.getRepositoryDirectory()
+      val gpgIdentifierFile =
+        File(repoRoot, directory.text.toString()).findTillRoot(".gpg-id", repoRoot)
+          ?: File(repoRoot, ".gpg-id").apply { createNewFile() }
+      val gpgIdentifiers =
+        gpgIdentifierFile
+          .readLines()
+          .filter { it.isNotBlank() }
+          .map { line ->
+            GpgIdentifier.fromString(line)
+              ?: run {
+                // The line being empty means this is most likely an empty `.gpg-id`
+                // file we created. Skip the validation so we can make the user add a
+                // real ID.
+                if (line.isEmpty()) return@run
+                if (line.removePrefix("0x").matches("[a-fA-F0-9]{8}".toRegex()).not()) {
+                  snackbar(message = resources.getString(R.string.invalid_gpg_id))
+                }
+                return@with
+              }
+          }
+          .filterIsInstance<GpgIdentifier>()
+      if (gpgIdentifiers.isEmpty()) {
+        error("Failed to parse identifiers from .gpg-id")
+      }
       val content = "$editPass\n$editExtra"
       val path =
         when {
@@ -360,7 +388,7 @@ class PasswordCreationActivity : BasePgpActivity() {
             val result =
               withContext(Dispatchers.IO) {
                 val outputStream = ByteArrayOutputStream()
-                repository.encrypt(content.byteInputStream(), outputStream)
+                repository.encrypt(gpgIdentifiers, content.byteInputStream(), outputStream)
                 outputStream
               }
             val file = File(path)
@@ -457,6 +485,23 @@ class PasswordCreationActivity : BasePgpActivity() {
     }
   }
 
+  @Suppress("ReturnCount")
+  private fun File.findTillRoot(fileName: String, rootPath: File): File? {
+    val gpgFile = File(this, fileName)
+    if (gpgFile.exists()) return gpgFile
+
+    if (this.absolutePath == rootPath.absolutePath) {
+      return null
+    }
+
+    val parent = parentFile
+    return if (parent != null && parent.exists()) {
+      parent.findTillRoot(fileName, rootPath)
+    } else {
+      null
+    }
+  }
+
   companion object {
 
     private const val KEY_PWGEN_TYPE_CLASSIC = "classic"
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index d2c9ab06..9997f6aa 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -299,6 +299,7 @@
   <string name="otp_import_success">Successfully imported TOTP configuration</string>
   <string name="otp_import_failure">Failed to import TOTP configuration</string>
   <string name="exporting_passwords">Exporting passwords…</string>
+  <string name="invalid_gpg_id">Found .gpg-id, but it contains an invalid key ID, fingerprint or user ID</string>
   <string name="invalid_filename_text">File name must not contain \'/\', set directory above</string>
   <string name="directory_hint">Directory</string>
   <string name="new_folder_set_gpg_key">Set GPG key for directory</string>
diff --git a/crypto-common/src/main/kotlin/app/passwordstore/crypto/CryptoHandler.kt b/crypto-common/src/main/kotlin/app/passwordstore/crypto/CryptoHandler.kt
index f8995bf6..ea42af6d 100644
--- a/crypto-common/src/main/kotlin/app/passwordstore/crypto/CryptoHandler.kt
+++ b/crypto-common/src/main/kotlin/app/passwordstore/crypto/CryptoHandler.kt
@@ -14,13 +14,13 @@ import java.io.OutputStream
 public interface CryptoHandler<Key> {
 
   /**
-   * Decrypt the given [ciphertextStream] using a [secretKey] and [passphrase], and writes the
-   * resultant plaintext to [outputStream]. The returned [Result] should be checked to ensure it is
-   * **not** an instance of [com.github.michaelbull.result.Err] before the contents of
+   * Decrypt the given [ciphertextStream] using a set of potential [keys] and [passphrase], and
+   * writes the resultant plaintext to [outputStream]. The returned [Result] should be checked to
+   * ensure it is **not** an instance of [com.github.michaelbull.result.Err] before the contents of
    * [outputStream] are used.
    */
   public fun decrypt(
-    secretKey: Key,
+    keys: List<Key>,
     passphrase: String,
     ciphertextStream: InputStream,
     outputStream: OutputStream,
diff --git a/crypto-pgpainless/src/main/kotlin/app/passwordstore/crypto/PGPainlessCryptoHandler.kt b/crypto-pgpainless/src/main/kotlin/app/passwordstore/crypto/PGPainlessCryptoHandler.kt
index 64ad426f..74f880a2 100644
--- a/crypto-pgpainless/src/main/kotlin/app/passwordstore/crypto/PGPainlessCryptoHandler.kt
+++ b/crypto-pgpainless/src/main/kotlin/app/passwordstore/crypto/PGPainlessCryptoHandler.kt
@@ -12,12 +12,12 @@ import app.passwordstore.crypto.errors.UnknownError
 import com.github.michaelbull.result.Result
 import com.github.michaelbull.result.mapError
 import com.github.michaelbull.result.runCatching
-import java.io.ByteArrayInputStream
 import java.io.InputStream
 import java.io.OutputStream
 import javax.inject.Inject
 import org.bouncycastle.openpgp.PGPPublicKeyRing
 import org.bouncycastle.openpgp.PGPPublicKeyRingCollection
+import org.bouncycastle.openpgp.PGPSecretKeyRing
 import org.bouncycastle.openpgp.PGPSecretKeyRingCollection
 import org.pgpainless.PGPainless
 import org.pgpainless.decryption_verification.ConsumerOptions
@@ -25,23 +25,25 @@ import org.pgpainless.encryption_signing.EncryptionOptions
 import org.pgpainless.encryption_signing.ProducerOptions
 import org.pgpainless.exception.WrongPassphraseException
 import org.pgpainless.key.protection.PasswordBasedSecretKeyRingProtector
-import org.pgpainless.key.util.KeyRingUtils
 import org.pgpainless.util.Passphrase
 
 public class PGPainlessCryptoHandler @Inject constructor() : CryptoHandler<PGPKey> {
 
   public override fun decrypt(
-    secretKey: PGPKey,
+    keys: List<PGPKey>,
     passphrase: String,
     ciphertextStream: InputStream,
     outputStream: OutputStream,
   ): Result<Unit, CryptoHandlerException> =
     runCatching {
-        val pgpSecretKeyRing = PGPainless.readKeyRing().secretKeyRing(secretKey.contents)
-        val keyringCollection = PGPSecretKeyRingCollection(listOf(pgpSecretKeyRing))
+        if (keys.isEmpty()) throw NoKeysProvided("No keys provided for encryption")
+        val keyringCollection =
+          keys
+            .map { key -> PGPainless.readKeyRing().secretKeyRing(key.contents) }
+            .run(::PGPSecretKeyRingCollection)
         val protector =
           PasswordBasedSecretKeyRingProtector.forKey(
-            pgpSecretKeyRing,
+            keyringCollection.first(),
             Passphrase.fromPassword(passphrase)
           )
         PGPainless.decryptAndOrVerify()
@@ -68,17 +70,14 @@ public class PGPainlessCryptoHandler @Inject constructor() : CryptoHandler<PGPKe
   ): Result<Unit, CryptoHandlerException> =
     runCatching {
         if (keys.isEmpty()) throw NoKeysProvided("No keys provided for encryption")
-        val publicKeyRings = arrayListOf<PGPPublicKeyRing>()
-        val armoredKeys =
-          keys.joinToString("\n") { key -> key.contents.decodeToString() }.toByteArray()
-        val secKeysStream = ByteArrayInputStream(armoredKeys)
-        publicKeyRings.addAll(
-          KeyRingUtils.publicKeyRingCollectionFrom(
-            PGPainless.readKeyRing().secretKeyRingCollection(secKeysStream)
-          )
-        )
-        val pubKeysStream = ByteArrayInputStream(armoredKeys)
-        publicKeyRings.addAll(PGPainless.readKeyRing().publicKeyRingCollection(pubKeysStream))
+        val publicKeyRings =
+          keys.mapNotNull(KeyUtils::tryParseKeyring).mapNotNull { keyRing ->
+            when (keyRing) {
+              is PGPPublicKeyRing -> keyRing
+              is PGPSecretKeyRing -> PGPainless.extractCertificate(keyRing)
+              else -> null
+            }
+          }
         require(keys.size == publicKeyRings.size) {
           "Failed to parse all keys: keys=${keys.size},parsed=${publicKeyRings.size}"
         }
diff --git a/crypto-pgpainless/src/test/kotlin/app/passwordstore/crypto/PGPainlessCryptoHandlerTest.kt b/crypto-pgpainless/src/test/kotlin/app/passwordstore/crypto/PGPainlessCryptoHandlerTest.kt
index 6a20fe25..80c8dc7c 100644
--- a/crypto-pgpainless/src/test/kotlin/app/passwordstore/crypto/PGPainlessCryptoHandlerTest.kt
+++ b/crypto-pgpainless/src/test/kotlin/app/passwordstore/crypto/PGPainlessCryptoHandlerTest.kt
@@ -46,7 +46,7 @@ class PGPainlessCryptoHandlerTest {
     val plaintextStream = ByteArrayOutputStream()
     val decryptRes =
       cryptoHandler.decrypt(
-        secretKey,
+        listOf(secretKey),
         CryptoConstants.KEY_PASSPHRASE,
         ciphertextStream.toByteArray().inputStream(),
         plaintextStream,
@@ -68,7 +68,7 @@ class PGPainlessCryptoHandlerTest {
     val plaintextStream = ByteArrayOutputStream()
     val result =
       cryptoHandler.decrypt(
-        secretKey,
+        listOf(secretKey),
         "very incorrect passphrase",
         ciphertextStream.toByteArray().inputStream(),
         plaintextStream,