# siv-mode

**Repository Path**: mirrors_patrickfav/siv-mode

## Basic Information

- **Project Name**: siv-mode
- **Description**: RFC 5297 SIV mode of operation in Java
- **Primary Language**: Unknown
- **License**: MIT
- **Default Branch**: develop
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-09-25
- **Last Updated**: 2026-04-05

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# RFC 5297 SIV mode of operation in Java

[![Build Status](https://travis-ci.org/cryptomator/siv-mode.svg?branch=develop)](https://travis-ci.org/cryptomator/siv-mode)
[![Codacy Badge](https://api.codacy.com/project/badge/Grade/8b274788dab046259a40e56688236790)](https://www.codacy.com/app/cryptomator/siv-mode)
[![Codacy Badge](https://api.codacy.com/project/badge/Coverage/8b274788dab046259a40e56688236790)](https://www.codacy.com/app/cryptomator/siv-mode)
[![Known Vulnerabilities](https://snyk.io/test/github/cryptomator/siv-mode/badge.svg)](https://snyk.io/test/github/cryptomator/siv-mode)
[![Maven Central](https://img.shields.io/maven-central/v/org.cryptomator/siv-mode.svg?maxAge=86400)](https://repo1.maven.org/maven2/org/cryptomator/siv-mode/)
[![Javadocs](http://www.javadoc.io/badge/org.cryptomator/siv-mode.svg)](http://www.javadoc.io/doc/org.cryptomator/siv-mode)

## Features
- No dependencies (required BouncyCastle classes are repackaged)
- Passes official RFC 5297 test vectors
- Constant time authentication
- Defaults on AES, but supports any block cipher with a 128-bit block size.
- Supports any key sizes that the block cipher supports (e.g. 128/192/256-bit keys for AES)
- Thread-safe
- Compatible with Android API Level 16 (since version 1.2.0)

## Audits
- [Version 1.0.8 audit by Tim McLean](https://www.chosenplaintext.ca/publications/20161104-siv-mode-report.pdf) (Issues fixed with 1.1.0)
- [Version 1.2.1 audit by Cure53](https://cryptomator.org/audits/2017-11-27%20crypto%20cure53.pdf)

| Finding | Comment |
|---|---|
| 1u1-22-001 | The GPG key is used exclusively for the Maven repositories, is designed for signing only and is protected by a 30-character generated password (alphabet size: 96 chars). It is iterated and salted (SHA1 with 20971520 iterations). An offline attack is also very unattractive. Apart from that, this finding has no influence on the Tresor apps<sup>[1](#footnote-tresor-apps)</sup>. This was not known to Cure53 at the time of reporting. |
| 1u1-22-002 | As per contract of `BlockCipher#processBlock(byte[], int, byte[], int)`, `JceAesBlockCipher` is designed to encrypt or decrypt just **one single block** at a time. JCE doesn't allow us to retrieve the plain cipher without a mode, so we explicitly request `AES/ECB/NoPadding`. This is by design, because we want the plain cipher for a single 128 bit block without any mode. We're not actually using ECB mode. |

## Usage
```java
private static final SivMode AES_SIV = new SivMode();

public void encrypt() {
  byte[] encrypted = AES_SIV.encrypt(ctrKey, macKey, "hello world".getBytes());
  byte[] decrypted = AES_SIV.decrypt(ctrKey, macKey, encrypted);
}

public void encryptWithAssociatedData() {
  byte[] encrypted = AES_SIV.encrypt(ctrKey, macKey, "hello world".getBytes(), "associated".getBytes(), "data".getBytes());
  byte[] decrypted = AES_SIV.decrypt(ctrKey, macKey, encrypted, "associated".getBytes(), "data".getBytes());
}
```

## Maven integration

```xml
<dependencies>
  <dependency>
    <groupId>org.cryptomator</groupId>
    <artifactId>siv-mode</artifactId>
    <version>1.3.0</version>
  </dependency>
</dependencies>
```

## JPMS

From version 1.3.0 onwards this library is an explicit module with the name `org.cryptomator.siv`. You can use it by adding the following line to your `module-info.java`.

```java
requires org.cryptomator.siv;
```

Because BouncyCastle classes are shaded, this library only depends on `java.base`.

## License
Distributed under the MIT X Consortium license. See the LICENSE file for more info.

---

<sup><a name="footnote-tresor-apps">1</a></sup> The Cure53 pentesting was performed during the development of the apps for 1&1 Mail & Media GmbH.