3 files changed, 39 insertions, 0 deletions
diff --git a/crypto-common/api/crypto-common.api b/crypto-common/api/crypto-common.api
new file mode 100644
index 00000000..7493379c
--- /dev/null
+++ b/crypto-common/api/crypto-common.api
@@ -0,0 +1,6 @@
+public abstract interface class dev/msfjarvis/aps/data/crypto/CryptoHandler {
+	public abstract fun canHandle (Ljava/lang/String;)Z
+	public abstract fun decrypt (Ljava/lang/String;[B[B)[B
+	public abstract fun encrypt (Ljava/lang/String;[B)[B
+}
+
diff --git a/crypto-common/build.gradle.kts b/crypto-common/build.gradle.kts
new file mode 100644
index 00000000..c1f3eef8
--- /dev/null
+++ b/crypto-common/build.gradle.kts
@@ -0,0 +1,8 @@
+/*
+ * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+plugins {
+  kotlin("jvm")
+  `aps-plugin`
+}
diff --git a/crypto-common/src/main/kotlin/dev/msfjarvis/aps/data/crypto/CryptoHandler.kt b/crypto-common/src/main/kotlin/dev/msfjarvis/aps/data/crypto/CryptoHandler.kt
new file mode 100644
index 00000000..453613a4
--- /dev/null
+++ b/crypto-common/src/main/kotlin/dev/msfjarvis/aps/data/crypto/CryptoHandler.kt
@@ -0,0 +1,25 @@
+/*
+ * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package dev.msfjarvis.aps.data.crypto
+
+/** Generic interface to implement cryptographic operations on top of. */
+public interface CryptoHandler {
+
+  /**
+   * Decrypt the given [ciphertext] using a [privateKey] and [passphrase], returning a [ByteArray]
+   * corresponding to the decrypted plaintext.
+   */
+  public fun decrypt(privateKey: String, passphrase: ByteArray, ciphertext: ByteArray): ByteArray
+
+  /**
+   * Encrypt the given [plaintext] to the provided [publicKey], returning the encrypted ciphertext
+   * as a [ByteArray]
+   */
+  public fun encrypt(publicKey: String, plaintext: ByteArray): ByteArray
+
+  /** Given a [fileName], return whether this instance can handle it. */
+  public fun canHandle(fileName: String): Boolean
+}