feat(crypto-pgpainless): add `KeyUtils#isKeyUsable`

1 files changed, 13 insertions, 0 deletions

diff --git a/crypto-pgpainless/src/main/kotlin/app/passwordstore/crypto/KeyUtils.kt b/crypto-pgpainless/src/main/kotlin/app/passwordstore/crypto/KeyUtils.kt
index 3c36060f..5b23dc18 100644
--- a/crypto-pgpainless/src/main/kotlin/app/passwordstore/crypto/KeyUtils.kt
+++ b/crypto-pgpainless/src/main/kotlin/app/passwordstore/crypto/KeyUtils.kt
@@ -10,6 +10,7 @@ import app.passwordstore.crypto.PGPIdentifier.UserId
 import com.github.michaelbull.result.get
 import com.github.michaelbull.result.runCatching
 import org.bouncycastle.openpgp.PGPKeyRing
+import org.pgpainless.PGPainless
 import org.pgpainless.key.parsing.KeyRingReader
 
 /** Utility methods to deal with [PGPKey]s. */
@@ -36,4 +37,16 @@ public object KeyUtils {
     val keyRing = tryParseKeyring(key) ?: return null
     return UserId(keyRing.publicKey.userIDs.next())
   }
+
+  /**
+   * Tests if the given [key] can be used for encryption, which is a bare minimum necessity for the
+   * app.
+   */
+  public fun isKeyUsable(key: PGPKey): Boolean {
+    return runCatching {
+        val keyRing = tryParseKeyring(key) ?: return false
+        PGPainless.inspectKeyRing(keyRing).isUsableForEncryption
+      }
+      .get() != null
+  }
 }