├── .gitattributes ├── main_card.png ├── manifest.json ├── logo.svg ├── sw.js ├── how-encryption-works.md ├── self_hosting_guide.md ├── README.md └── LICENSE /.gitattributes: -------------------------------------------------------------------------------- 1 | index.html linguist-language=JavaScript 2 | -------------------------------------------------------------------------------- /main_card.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/RockwellShah/filekey/HEAD/main_card.png -------------------------------------------------------------------------------- /manifest.json: -------------------------------------------------------------------------------- 1 | { 2 | "short_name": "FileKey", 3 | "name": "FileKey", 4 | "icons": [ 5 | { 6 | "src": "/logo.svg", 7 | "type": "image/svg+xml", 8 | "sizes": "128x128" 9 | }, 10 | { 11 | "src": "/logo.svg", 12 | "type": "image/svg+xml", 13 | "sizes": "256x256" 14 | }, 15 | { 16 | "src": "/logo.svg", 17 | "type": "image/svg+xml", 18 | "sizes": "512x512" 19 | } 20 | ], 21 | "background_color": "#fff", 22 | "display": "standalone", 23 | "theme_color": "#fff", 24 | "scope": "/", 25 | "start_url": "/" 26 | } 27 | -------------------------------------------------------------------------------- /logo.svg: -------------------------------------------------------------------------------- 1 | 2 | 3 | -------------------------------------------------------------------------------- /sw.js: -------------------------------------------------------------------------------- 1 | let change_variable = "g"; 2 | self.addEventListener('install', event => { 3 | event.waitUntil(caches.open('v1').then(cache => { 4 | return cache.addAll(['/', ]); 5 | } 6 | )); 7 | } 8 | ); 9 | self.addEventListener('activate', event => { 10 | const cacheWhitelist = ['v1']; 11 | event.waitUntil(caches.keys().then(cacheNames => { 12 | return Promise.all(cacheNames.map(cacheName => { 13 | if (!cacheWhitelist.includes(cacheName)) { 14 | return caches.delete(cacheName); 15 | } 16 | } 17 | )); 18 | } 19 | )); 20 | } 21 | ); 22 | self.addEventListener('fetch', event => { 23 | event.respondWith(caches.match(event.request).then(cachedResponse => { 24 | if (cachedResponse) { 25 | return cachedResponse; 26 | } 27 | return fetch(event.request).then(networkResponse => { 28 | return caches.open('v1').then(cache => { 29 | cache.put(event.request, networkResponse.clone()); 30 | return networkResponse; 31 | } 32 | ); 33 | } 34 | ); 35 | } 36 | )); 37 | } 38 | ); 39 | self.addEventListener('install', event => { 40 | self.skipWaiting(); 41 | } 42 | ); 43 | self.addEventListener('activate', event => { 44 | event.waitUntil(self.clients.claim()); 45 | } 46 | ); 47 | self.addEventListener('message', messageReceiver); 48 | function messageReceiver(msg) { 49 | if (msg.ports) { 50 | switch (msg.data.type) { 51 | case "check_change_variable": 52 | msg.ports[0].postMessage({ 53 | change_variable 54 | }); 55 | break; 56 | } 57 | } 58 | } 59 | -------------------------------------------------------------------------------- /how-encryption-works.md: -------------------------------------------------------------------------------- 1 | ### 🔐 Encryption Process 2 | 3 | FileKey first requires the generation of a passkey, stored on either your password manager or security key device, using the app’s domain as the relying party. Once a passkey has been created, it can then pass a static message through WebAuthn (with PRF support) to generate a deterministic random value. 4 | 5 | Using this value, FileKey derives a 256-bit encryption key via HKDF. A random salt is used alongside the HKDF to produce a key suitable for AES-GCM encryption. This derived key is then used to encrypt or decrypt a file. A new derived key is generated for each file. 6 | 7 | All low-level cryptographic operations use the browser's built-in `SubtleCrypto` API. Every encrypted file includes a unique 16-byte random salt. 8 | 9 | --- 10 | 11 | ### 🧠 Share Key Encryption Process (Technical Details) 12 | 13 | 1. **WebAuthn PRF:** The process starts by generating a PRF (pseudorandom function) output from the user's WebAuthn passkey. 14 | 2. **HKDF Generation:** The PRF output is passed into HKDF to generate a seed value. 15 | 3. **Deterministic ECDH Key Pair:** 16 | Using this seed, FileKey deterministically generates an ECDH (Elliptic Curve Diffie-Hellman) key pair on the P-521 curve. 17 | 4. **Key Formatting:** 18 | - Private key is encoded in PKCS#8 19 | - Public key is encoded in raw format 20 | 5. **Key Import:** 21 | Both keys are imported into the browser’s `SubtleCrypto` API for cryptographic use. 22 | 6. **Shared Secret Derivation:** 23 | When encrypting a file for someone else, FileKey derives an AES-GCM key using: 24 | - Your private ECDH key 25 | - The recipient’s public ECDH key 26 | - A randomly generated salt 27 | 7. **Encryption:** 28 | The derived AES-GCM key encrypts the file content. 29 | 30 | --- 31 | 32 | ### 🔐 Encrypted Shared File Includes: 33 | 34 | - The sender’s **public ECDH key** (so the recipient knows which key to use) 35 | - The **random salt** (used for key derivation) 36 | - The **encrypted file content** 37 | 38 | --- 39 | 40 | ### 💡 Why This Matters 41 | 42 | This approach eliminates the need to store or transmit the ECDH key pair. 43 | Users can regenerate the exact same key pair on any device just by authenticating with their passkey — making it resilient to data loss or device compromise. 44 | -------------------------------------------------------------------------------- /self_hosting_guide.md: -------------------------------------------------------------------------------- 1 | # 🐳 Self-Hosting FileKey as a Dockerized PWA 2 | A big thank you to Wintech147 for putting this guide together! 3 | 4 | --- 5 | 6 | ## ✅ Prerequisites 7 | 8 | - Docker already installed both on your build machine and on a docker host 9 | - Nginx Proxy Manager is installed and accessible with LetsEncrypt configured 10 | - You own a domain (e.g., `filekey.example.com`) 11 | - You have DNS configured whether internally or externally that points to your proxy for traffic 12 | 13 | --- 14 | 15 | This guide walks you through how to: 16 | 17 | 1. Clone the [FileKey](https://github.com/RockwellShah/filekey) repo 18 | 2. Add required PWA icons (optional) 19 | 3. Create a `Dockerfile` to serve it with Nginx 20 | 4. Build and push a Docker image to Docker Hub 21 | 5. Deploy it using Docker Compose 22 | 23 | --- 24 | 25 | ## 📁 Project Structure 26 | 27 | ``` 28 | filekey/ 29 | ├── Dockerfile 30 | ├── docker-compose.yml 31 | ├── index.html 32 | ├── manifest.json 33 | ├── sw.js 34 | └── icons/ (optional) 35 | ├── icon-192.png 36 | └── icon-512.png 37 | ``` 38 | 39 | --- 40 | 41 | ## 🛠️ Step 1: Clone the GitHub Repository 42 | 43 | ```bash 44 | git clone https://github.com/RockwellShah/filekey.git 45 | cd filekey 46 | ``` 47 | 48 | --- 49 | 50 | ## 🎨 Step 2: Add PWA Icons (Optional) 51 | 52 | Since the original repo doesn't include actual icons, create your own: 53 | 54 | 1. Create icons in your favorit app. For PWAs they are best in .png. 55 | 56 | 2. Update `manifest.json` withe icon name and location based on the structure from above: 57 | 58 | ```json 59 | "icons": [ 60 | { 61 | "src": "/icons/icon-192.png", 62 | "type": "image/png", 63 | "sizes": "192x192" 64 | }, 65 | { 66 | "src": "/icons/icon-512.png", 67 | "type": "image/png", 68 | "sizes": "512x512" 69 | } 70 | ] 71 | ``` 72 | (Editor's note: there is now an SVG version of the FileKey icon in the repo.) 73 | 74 | --- 75 | 76 | ## 🐳 Step 3: Create Dockerfile 77 | 78 | In the root of the cloned repo, create a file named `Dockerfile` and paste the below into it: 79 | 80 | ```dockerfile 81 | FROM nginx:alpine 82 | 83 | # Remove default Nginx page 84 | RUN rm -rf /usr/share/nginx/html/* 85 | 86 | # Copy static site into Nginx root 87 | COPY . /usr/share/nginx/html 88 | 89 | EXPOSE 80 90 | CMD ["nginx", "-g", "daemon off;"] 91 | ``` 92 | 93 | --- 94 | 95 | ## 🔨 Step 4: Build and Push Docker Image to Docker Hub 96 | 97 | This assumes you have Docker installed on your local dev machine. This is not where you will be running the container just building the container image. 98 | 99 | 1. Build the image and don't leave out that trailing period: 100 | ```bash 101 | docker build -t /filekey:filekeyv1 . 102 | ``` 103 | 104 | Now you can choose to copy the image to your local docker host that you want the containers to run on and do docker run with the local image. I prefer to keep my images stored in Docker Hub to allow for easy pulls onto various hosts I run which is what I'm showing below: 105 | 106 | 2. Log in to Docker Hub: 107 | ```bash 108 | docker login 109 | ``` 110 | 111 | 3. Push the image: 112 | ```bash 113 | docker push /filekey:latest 114 | ``` 115 | 116 | > Replace `` with your actual Docker Hub username. Use any tag you wish instead of 'latest' 117 | 118 | --- 119 | 120 | ## 🚀 Step 5: Deploy Using Docker Compose 121 | 122 | Create a `docker-compose.yml` file: 123 | 124 | ```yaml 125 | version: '3.8' 126 | 127 | services: 128 | filekey: 129 | image: /filekey:filekeyv1 130 | container_name: filekey 131 | ports: 132 | - "8080:80" 133 | restart: unless-stopped 134 | ``` 135 | 136 | Choose any port that is open on your docker host in my case it was 8080 but this can be anything. 137 | 138 | Deploy with: 139 | 140 | ```bash 141 | docker compose up -d 142 | ``` 143 | 144 | Or paste into **Portainer > Stacks > Add Stack**. 145 | 146 | --- 147 | 148 | ## 🔐 Step 6: Add to NGINX Proxy Manager (or something similiar) 149 | 150 | ### ➕ Add New Proxy Host 151 | 152 | - Go to your NGNIX Proxy Manager 153 | - Go to **"Proxy Hosts"** 154 | - Click **"Add Proxy Host"** 155 | 156 | #### Fill in the following: 157 | 158 | | Field | Value | 159 | |-------------------|-------------------------------------| 160 | | **Domain Names** | `filekey.example.com` | 161 | | **Scheme** | `http` | 162 | | **Forward Hostname / IP** | `your-docker-host-ip` or `localhost`if on the same host | 163 | | **Forward Port** | `8080` (or whatever FileKey is running on) | 164 | | **Cache Assets** | Optional | 165 | | **Block Common Exploits** | ✅ Recommended | 166 | | **Websockets Support** | ✅ Recommended | 167 | 168 | --- 169 | 170 | ### 🔒 Enable SSL (Let's Encrypt) 171 | 172 | - Go to the **SSL** tab 173 | - Check **“Enable SSL”** 174 | - Check **“Force SSL”** 175 | - Check **“HTTP/2 Support”** 176 | - Check **“HSTS Enabled”** 177 | - Choose **Choose your cert** 178 | 179 | Click **Save**. 180 | 181 | --- 182 | 183 | ## 🌐 Step 7: Access the App 184 | 185 | Once deployed and added to your proxy, visit: 186 | 187 | ``` 188 | https://filekey.example.com 189 | 190 | http://:8080 (if not using a proxy) 191 | ``` 192 | 193 | --- 194 | 195 | ## ✅ Summary 196 | 197 | | Step | Description | 198 | |-----------------------------|-------------------------------------------| 199 | | Clone & customize | Pull the repo, add icons, edit manifest and index.html | 200 | | Build image | `docker build -t yourname/filekey:tag .` | 201 | | Push to Docker Hub | `docker push yourname/filekey:tag` | 202 | | Deploy with Compose/Portainer | Map port 8080, restart unless stopped | 203 | | Add proxy host to NGINX Proxy Manager | docker host, port 8080, SSL | 204 | | PWA Ready | Installable with custom icon & manifest | 205 | 206 | --- 207 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # 🔐 FileKey 2 | 3 | FileKey is an offline web app that lets you quickly encrypt and share files using passkeys. No accounts, no tracking, no backend servers. Just local, offline security powered by passkeys. 4 | 5 | > 🛡️ **FileKey is open source and privacy-first.** 6 | 7 | --- 8 | 9 | ### 🚀 Features 10 | 11 | - ✅ **Free & Open Source** – Licensed under GPLv3. 12 | - ✅ **Accountless by Design** – No logins, no tracking. 13 | - ✅ **Passkey-Based Encryption** – Integrates with your existing security key or password manager. 14 | - ✅ **End-to-End Encrypted** – Only you can see your data. 15 | - ✅ **Secure Sharing** – Share files securely with “Share Keys” 16 | - ✅ **Offline** – Runs 100% offline in your browser. Can be installed locally as a PWA. 17 | 18 | --- 19 | 20 | ### 👨‍💻 How to Use FileKey 21 | 22 | 1. **Create your FileKey** 23 | Generate a secure passkey stored in your password manager or security key (like iCloud Keychain or Yubikey). 24 | 25 | 2. **Encrypt files** 26 | Drag and drop any file into FileKey — it's immediately encrypted with AES-256. 27 | 28 | 3. **Decrypt files** 29 | Drop the encrypted file back in. Your passkey unlocks it quickly, locally and securely. 30 | 31 | 4. **Share privately** 32 | Encrypt a file for someone else using their Share Key. Only they can open it. 33 | 34 | --- 35 | 36 | ### 💾 Supported Systems 37 | 38 | In order to use FileKey, you need a compatible password manager (Apple Passwords, Google Passwords, Windows Hello, etc) or a hardware security key that supports FIDO2 and PRF (like the YubiKey 5 and Bio Series). For hardware security keys, your browser and operating system both need to support WebAuthn and the PRF extension. Below is a non-exhaustive compatiblity table: 39 | 40 | | Platform | Supported Passkey Providers | Notes | 41 | |--------------|-------------------------------------|------------------------------------| 42 | | macOS | Apple Passwords, Yubikey, 1Password | Safari ≥ 17 or Chrome ≥ 112. Yubikeys will not work in Safari. | 43 | | Windows | 1Password, YubiKey | Edge ≥ 112 or Chrome ≥ 112. Requires Windows 11. | 44 | | Linux | YubiKey (via browser) | Latest version of Chrome or Chromium-based browsers. | 45 | | iOS | Apple Passwords, 1Password | Safari ≥ 17 or Chrome ≥ 112 | 46 | | Android | Google Passwords, 1Password, Yubikey | Chrome ≥ 112 | 47 | 48 |
49 | 50 | > ⚠️ **Notes:** 51 | > - Proton Pass and BitWarden won't work until they properly support PRF. 52 | > - Samsung Pass has been reported to work, despite not officially supporting PRF. 53 | > - Windows 10 and below does not support PRF, and thus won't work. 54 | > - Filekey will likely work with Chromium based browsers (e.g. Brave, Vivaldi, Opera) 55 | 56 | --- 57 | 58 | ### 🛠️ How the Encryption Works 59 | 60 | FileKey first requires the generation of a passkey, that will be stored on either your password manager or security key device, using the app’s domain as the relying party. Once a passkey has been created, it can then pass a static message through WebAuthn which interacts with a PRF in order to generate a deterministic random value. 61 | 62 | Using this deterministic random value, an HKDF with 256 bits of entropy is generated. The HKDF and a random salt is then used to derive a key to be used with AES-GCM. The derived key is then used to encrypt and decrypt the file. A new derived key is used for each additional file. 63 | 64 | All low-level cryptographic functions performed within this process are using the web’s built-in SubtleCrypto interface of the Web Crypto API. All encrypted files use a unique randomly generated salt, composed of a 16 byte hash. 65 | 66 | > 🛡️ **To understand more details of the encryption process, [see here](how-encryption-works.md).** 67 | 68 | --- 69 | 70 | ### 🔁 Sharing 71 | 72 | Every FileKey user has a unique **Share Key** — a long string that acts like a public address. You can find it in the menu under **"Your Share Key."** 73 | 74 | #### 📤 Sharing a File 75 | 76 | 1. Click the **"Share"** button next to any file. 77 | 2. Enter the recipient’s Share Key (they’ll need to provide this to you). 78 | 3. FileKey creates a special encrypted version only that recipient can unlock. Save and send the file (ending in `.shared_filekey`) via any method — email, messaging, file transfer, etc. 79 | 80 | #### 📥 Receiving a Shared File 81 | 82 | 1. Open FileKey and authenticate. 83 | 2. Drag and drop the shared file into FileKey. 84 | 3. FileKey detects that it’s a shared file and decrypts it using your key. 85 | 86 | #### 🔐 Security Details for Sharing 87 | 88 | - Your private keys **never** leave your device. 89 | - Shared files are locked to a specific recipient. 90 | - All encryption and decryption happen **entirely on your device** — no servers involved. 91 | - Files are secured with **AES-256** encryption. 92 | - Your Share Key does not need to be kept secret, it can be shared openly. 93 | 94 | > 🛡️ Share with confidence, knowing only your intended recipient can access the file. 95 | 96 | --- 97 | 98 | ### 🫥 What Happens if FileKey Disappears? 99 | 100 | If you are worried about relying on the FileKey website, you can always install FileKey locally as a progressive web app. It's easy, and only takes a few seconds. 101 | 102 | #### 💻 Desktop (Mac, Windows, Linux) with Chrome / Edge / Brave 103 | 104 | 1. Open FileKey in your browser. 105 | 2. Look for the “Install App” icon in the address bar (a little downward-pointing arrow with a computer/screen). 106 | 3. Click Install. 107 | 108 | FileKey will open as its own standalone app and appear in your Applications list, and will fully work offline. 109 | 110 | #### 📱 iOS (iPhone / iPad) 111 | 112 | Safari is required — only Safari supports PWAs fully on iOS. 113 | 114 | 1. Open FileKey in Safari. 115 | 2. Tap the Share icon (square with arrow). 116 | 3. Scroll down and tap Add to Home Screen. 117 | 4. Tap Add in the top-right corner. 118 | 119 | FileKey will now behave like a native app and can be used offline once cached. 120 | 121 | #### 🤖 Android with Chrome / Edge / Brave / Samsung Internet 122 | 123 | 1. Open FileKey in your browser. 124 | 2. You’ll see a banner that says “Add to Home screen” — tap it. 125 | 3. Or tap the ⋮ menu → Add to Home screen. 126 | 4. Confirm Install. 127 | 128 | You’ll now have a standalone FileKey app icon that works offline. 129 | 130 | --- 131 | 132 | ### 🙋‍♂️ Self-Hosting 133 | 134 | For those interested in self-hosting FileKey, user Wintech47 put [this awesome guide](self_hosting_guide.md) together. 135 | 136 | --- 137 | 138 | ### 📝 Review 139 | 140 | The famous french cybersecurity blogger Korben wrote a nice [breakdown of FileKey](https://korben.info/filekey-chiffrement-fichiers-passkeys-local-opensource.html) on his blog. 141 | 142 | --- 143 | 144 | ### 🔗 Links 145 | 146 | > **🔒 [filekey.app](https://filekey.app)** 147 | > *(Best in the latest versions of Chrome, Safari, or Edge)* 148 | 149 | > **📜 [Substack](https://filekey.substack.com/)** 150 | > *(Our official blog)* 151 | 152 | > **💬 [Signal Group](https://signal.group/#CjQKIDpdakX0nr1V00ciNv3dsWCFZgUwm_NylulFJz4VOUJ_EhBtY-bq759RNExzcCWMUGIB)** 153 | > *(Chat with us directly)* 154 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 3, 29 June 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU General Public License is a free, copyleft license for 11 | software and other kinds of works. 12 | 13 | The licenses for most software and other practical works are designed 14 | to take away your freedom to share and change the works. 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No Surrender of Others' Freedom. 541 | 542 | If conditions are imposed on you (whether by court order, agreement or 543 | otherwise) that contradict the conditions of this License, they do not 544 | excuse you from the conditions of this License. If you cannot convey a 545 | covered work so as to satisfy simultaneously your obligations under this 546 | License and any other pertinent obligations, then as a consequence you may 547 | not convey it at all. For example, if you agree to terms that obligate you 548 | to collect a royalty for further conveying from those to whom you convey 549 | the Program, the only way you could satisfy both those terms and this 550 | License would be to refrain entirely from conveying the Program. 551 | 552 | 13. Use with the GNU Affero General Public License. 553 | 554 | Notwithstanding any other provision of this License, you have 555 | permission to link or combine any covered work with a work licensed 556 | under version 3 of the GNU Affero General Public License into a single 557 | combined work, and to convey the resulting work. The terms of this 558 | License will continue to apply to the part which is the covered work, 559 | but the special requirements of the GNU Affero General Public License, 560 | section 13, concerning interaction through a network will apply to the 561 | combination as such. 562 | 563 | 14. Revised Versions of this License. 564 | 565 | The Free Software Foundation may publish revised and/or new versions of 566 | the GNU General Public License from time to time. Such new versions will 567 | be similar in spirit to the present version, but may differ in detail to 568 | address new problems or concerns. 569 | 570 | Each version is given a distinguishing version number. If the 571 | Program specifies that a certain numbered version of the GNU General 572 | Public License "or any later version" applies to it, you have the 573 | option of following the terms and conditions either of that numbered 574 | version or of any later version published by the Free Software 575 | Foundation. If the Program does not specify a version number of the 576 | GNU General Public License, you may choose any version ever published 577 | by the Free Software Foundation. 578 | 579 | If the Program specifies that a proxy can decide which future 580 | versions of the GNU General Public License can be used, that proxy's 581 | public statement of acceptance of a version permanently authorizes you 582 | to choose that version for the Program. 583 | 584 | Later license versions may give you additional or different 585 | permissions. However, no additional obligations are imposed on any 586 | author or copyright holder as a result of your choosing to follow a 587 | later version. 588 | 589 | 15. Disclaimer of Warranty. 590 | 591 | THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY 592 | APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT 593 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY 594 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, 595 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 596 | PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM 597 | IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF 598 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 599 | 600 | 16. Limitation of Liability. 601 | 602 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 603 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS 604 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY 605 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE 606 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF 607 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD 608 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), 609 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF 610 | SUCH DAMAGES. 611 | 612 | 17. Interpretation of Sections 15 and 16. 613 | 614 | If the disclaimer of warranty and limitation of liability provided 615 | above cannot be given local legal effect according to their terms, 616 | reviewing courts shall apply local law that most closely approximates 617 | an absolute waiver of all civil liability in connection with the 618 | Program, unless a warranty or assumption of liability accompanies a 619 | copy of the Program in return for a fee. 620 | 621 | END OF TERMS AND CONDITIONS 622 | 623 | How to Apply These Terms to Your New Programs 624 | 625 | If you develop a new program, and you want it to be of the greatest 626 | possible use to the public, the best way to achieve this is to make it 627 | free software which everyone can redistribute and change under these terms. 628 | 629 | To do so, attach the following notices to the program. It is safest 630 | to attach them to the start of each source file to most effectively 631 | state the exclusion of warranty; and each file should have at least 632 | the "copyright" line and a pointer to where the full notice is found. 633 | 634 | 635 | Copyright (C) 636 | 637 | This program is free software: you can redistribute it and/or modify 638 | it under the terms of the GNU General Public License as published by 639 | the Free Software Foundation, either version 3 of the License, or 640 | (at your option) any later version. 641 | 642 | This program is distributed in the hope that it will be useful, 643 | but WITHOUT ANY WARRANTY; without even the implied warranty of 644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 645 | GNU General Public License for more details. 646 | 647 | You should have received a copy of the GNU General Public License 648 | along with this program. If not, see . 649 | 650 | Also add information on how to contact you by electronic and paper mail. 651 | 652 | If the program does terminal interaction, make it output a short 653 | notice like this when it starts in an interactive mode: 654 | 655 | Copyright (C) 656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 657 | This is free software, and you are welcome to redistribute it 658 | under certain conditions; type `show c' for details. 659 | 660 | The hypothetical commands `show w' and `show c' should show the appropriate 661 | parts of the General Public License. Of course, your program's commands 662 | might be different; for a GUI interface, you would use an "about box". 663 | 664 | You should also get your employer (if you work as a programmer) or school, 665 | if any, to sign a "copyright disclaimer" for the program, if necessary. 666 | For more information on this, and how to apply and follow the GNU GPL, see 667 | . 668 | 669 | The GNU General Public License does not permit incorporating your program 670 | into proprietary programs. If your program is a subroutine library, you 671 | may consider it more useful to permit linking proprietary applications with 672 | the library. If this is what you want to do, use the GNU Lesser General 673 | Public License instead of this License. But first, please read 674 | . 675 | --------------------------------------------------------------------------------