From 20f32926bb1d72f0cc91181e904b5dbaede44dff Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Mon, 31 Aug 2020 12:26:07 +0200
Subject: [PATCH] Add Passphrase.fromPassword() and
 PasswordBasedSecretKeyRingProtector.forKey() factory methods

---
 .../PasswordBasedSecretKeyRingProtector.java    | 17 +++++++++++++++++
 .../java/org/pgpainless/util/Passphrase.java    | 10 ++++++++++
 2 files changed, 27 insertions(+)

diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/protection/PasswordBasedSecretKeyRingProtector.java b/pgpainless-core/src/main/java/org/pgpainless/key/protection/PasswordBasedSecretKeyRingProtector.java
index 56e01cd5..9232b1e4 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/protection/PasswordBasedSecretKeyRingProtector.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/protection/PasswordBasedSecretKeyRingProtector.java
@@ -19,12 +19,14 @@ import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 import org.bouncycastle.openpgp.PGPException;
+import org.bouncycastle.openpgp.PGPKeyRing;
 import org.bouncycastle.openpgp.operator.PBESecretKeyDecryptor;
 import org.bouncycastle.openpgp.operator.PBESecretKeyEncryptor;
 import org.bouncycastle.openpgp.operator.PGPDigestCalculatorProvider;
 import org.bouncycastle.openpgp.operator.bc.BcPBESecretKeyDecryptorBuilder;
 import org.bouncycastle.openpgp.operator.bc.BcPBESecretKeyEncryptorBuilder;
 import org.bouncycastle.openpgp.operator.bc.BcPGPDigestCalculatorProvider;
+import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
 import org.pgpainless.util.Passphrase;
 
 /**
@@ -51,6 +53,21 @@ public class PasswordBasedSecretKeyRingProtector implements SecretKeyRingProtect
         this.passphraseProvider = passphraseProvider;
     }
 
+    public static PasswordBasedSecretKeyRingProtector forKey(PGPKeyRing keyRing, Passphrase passphrase) {
+        KeyRingProtectionSettings protectionSettings = new KeyRingProtectionSettings(SymmetricKeyAlgorithm.AES_256);
+        SecretKeyPassphraseProvider passphraseProvider = new SecretKeyPassphraseProvider() {
+            @Override
+            @Nullable
+            public Passphrase getPassphraseFor(Long keyId) {
+                if (keyRing.getPublicKey().getKeyID() == keyId) {
+                    return passphrase;
+                }
+                return null;
+            }
+        };
+        return new PasswordBasedSecretKeyRingProtector(protectionSettings, passphraseProvider);
+    }
+
     @Override
     @Nullable
     public PBESecretKeyDecryptor getDecryptor(Long keyId) {
diff --git a/pgpainless-core/src/main/java/org/pgpainless/util/Passphrase.java b/pgpainless-core/src/main/java/org/pgpainless/util/Passphrase.java
index 7d9e9411..480c584b 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/util/Passphrase.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/util/Passphrase.java
@@ -34,6 +34,16 @@ public class Passphrase {
         this.chars = chars;
     }
 
+    /**
+     * Create a {@link Passphrase} from a {@link String}.
+     *
+     * @param password password
+     * @return passphrase
+     */
+    public static Passphrase fromPassword(String password) {
+        return new Passphrase(password.toCharArray());
+    }
+
     /**
      * Overwrite the char array with spaces and mark the {@link Passphrase} as invalidated.
      */