pkcs8: Add support for unprotected PKCS#8 containers

src/libstrongswan/plugins/pkcs8/pkcs8_builder.c

@@ -121,6 +121,32 @@ end:
 	return key;
 }
 
+/**
+ * Try to decrypt the given blob using the given password and pkcs5 object.
+ */
+static private_key_t *decrypt_private_key_pw(key_type_t type, pkcs5_t *pkcs5,
+											 chunk_t blob, chunk_t password)
+{
+	private_key_t *private_key;
+	chunk_t decrypted;
+
+	if (!pkcs5->decrypt(pkcs5, password, blob, &decrypted))
+	{
+		return NULL;
+	}
+	/* do a quick check to validate whether the password was correct */
+	if (!is_asn1(decrypted))
+	{
+		chunk_clear(&decrypted);
+		return NULL;
+	}
+	private_key = lib->creds->create(lib->creds, CRED_PRIVATE_KEY,
+									 type, BUILD_BLOB_ASN1_DER,
+									 decrypted, BUILD_END);
+	chunk_clear(&decrypted);
+	return private_key;
+}
+
 /**
  * Try to decrypt the given blob with multiple passwords using the given
  * pkcs5 object.
@@ -130,36 +156,26 @@ static private_key_t *decrypt_private_key(key_type_t type, pkcs5_t *pkcs5,
 {
 	enumerator_t *enumerator;
 	shared_key_t *shared;
-	private_key_t *private_key = NULL;
+	private_key_t *private_key;
+
+	private_key = decrypt_private_key_pw(type, pkcs5, blob, chunk_empty);
+	if (private_key)
+	{
+		return private_key;
+	}
 
 	enumerator = lib->credmgr->create_shared_enumerator(lib->credmgr,
 										SHARED_PRIVATE_KEY_PASS, NULL, NULL);
 	while (enumerator->enumerate(enumerator, &shared, NULL, NULL))
 	{
-		chunk_t decrypted;
-
-		if (!pkcs5->decrypt(pkcs5, shared->get_key(shared), blob, &decrypted))
-		{
-			continue;
-		}
-		/* do a quick check to validate whether the password was correct */
-		if (!is_asn1(decrypted))
-		{
-			chunk_clear(&decrypted);
-			continue;
-		}
-		private_key = lib->creds->create(lib->creds, CRED_PRIVATE_KEY,
-										 type, BUILD_BLOB_ASN1_DER,
-										 decrypted, BUILD_END);
+		private_key = decrypt_private_key_pw(type, pkcs5, blob,
+											 shared->get_key(shared));
 		if (private_key)
 		{
-			chunk_clear(&decrypted);
 			break;
 		}
-		chunk_free(&decrypted);
 	}
 	enumerator->destroy(enumerator);
-
 	return private_key;
 }