From ee1987a41db3b68ac9d5da905327ce64a0123297 Mon Sep 17 00:00:00 2001 From: Dominic Ricottone Date: Wed, 13 Apr 2022 00:27:32 -0500 Subject: [PATCH] Initial commit --- .gitignore | 3 + Dockerfile | 12 + LICENSE.md | 595 ++++++++++++++++++++++++++++++++++++++++++++++ Makefile | 6 + client/chat.js | 126 ++++++++++ client/index.html | 17 ++ server/.gitignore | 3 + server/Makefile | 9 + server/go.mod | 5 + server/main.go | 126 ++++++++++ 10 files changed, 902 insertions(+) create mode 100644 .gitignore create mode 100644 Dockerfile create mode 100644 LICENSE.md create mode 100644 Makefile create mode 100644 client/chat.js create mode 100644 client/index.html create mode 100644 server/.gitignore create mode 100644 server/Makefile create mode 100644 server/go.mod create mode 100644 server/main.go diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..b328ebb --- /dev/null +++ b/.gitignore @@ -0,0 +1,3 @@ +server/go.sum +server/server + diff --git a/Dockerfile b/Dockerfile new file mode 100644 index 0000000..dbf5c11 --- /dev/null +++ b/Dockerfile @@ -0,0 +1,12 @@ +FROM golang:alpine + +WORKDIR /app +COPY server/* ./ +RUN go mod download +RUN go build -o /app/server-bin + +EXPOSE 40080 +RUN adduser -H -D -u 1001 me +USER me:me +CMD [ "/app/server-bin" ] + diff --git a/LICENSE.md b/LICENSE.md new file mode 100644 index 0000000..175443c --- /dev/null +++ b/LICENSE.md @@ -0,0 +1,595 @@ +GNU General Public License +========================== + +_Version 3, 29 June 2007_ +_Copyright © 2007 Free Software Foundation, Inc. <>_ + +Everyone is permitted to copy and distribute verbatim copies of this license +document, but changing it is not allowed. + +## Preamble + +The GNU General Public License is a free, copyleft license for software and other +kinds of works. + +The licenses for most software and other practical works are designed to take away +your freedom to share and change the works. By contrast, the GNU General Public +License is intended to guarantee your freedom to share and change all versions of a +program--to make sure it remains free software for all its users. We, the Free +Software Foundation, use the GNU General Public License for most of our software; it +applies also to any other work released this way by its authors. You can apply it to +your programs, too. + +When we speak of free software, we are referring to freedom, not price. Our General +Public Licenses are designed to make sure that you have the freedom to distribute +copies of free software (and charge for them if you wish), that you receive source +code or can get it if you want it, that you can change the software or use pieces of +it in new free programs, and that you know you can do these things. + +To protect your rights, we need to prevent others from denying you these rights or +asking you to surrender the rights. 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Protecting Users' Legal Rights From Anti-Circumvention Law + +No covered work shall be deemed part of an effective technological measure under any +applicable law fulfilling obligations under article 11 of the WIPO copyright treaty +adopted on 20 December 1996, or similar laws prohibiting or restricting circumvention +of such measures. + +When you convey a covered work, you waive any legal power to forbid circumvention of +technological measures to the extent such circumvention is effected by exercising +rights under this License with respect to the covered work, and you disclaim any +intention to limit operation or modification of the work as a means of enforcing, +against the work's users, your or third parties' legal rights to forbid circumvention +of technological measures. + +### 4. Conveying Verbatim Copies + +You may convey verbatim copies of the Program's source code as you receive it, in any +medium, provided that you conspicuously and appropriately publish on each copy an +appropriate copyright notice; keep intact all notices stating that this License and +any non-permissive terms added in accord with section 7 apply to the code; keep +intact all notices of the absence of any warranty; and give all recipients a copy of +this License along with the Program. + +You may charge any price or no price for each copy that you convey, and you may offer +support or warranty protection for a fee. + +### 5. 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Conveying Non-Source Forms + +You may convey a covered work in object code form under the terms of sections 4 and +5, provided that you also convey the machine-readable Corresponding Source under the +terms of this License, in one of these ways: + +* **a)** Convey the object code in, or embodied in, a physical product (including a +physical distribution medium), accompanied by the Corresponding Source fixed on a +durable physical medium customarily used for software interchange. +* **b)** Convey the object code in, or embodied in, a physical product (including a +physical distribution medium), accompanied by a written offer, valid for at least +three years and valid for as long as you offer spare parts or customer support for +that product model, to give anyone who possesses the object code either **(1)** a copy of +the Corresponding Source for all the software in the product that is covered by this +License, on a durable physical medium customarily used for software interchange, for +a price no more than your reasonable cost of physically performing this conveying of +source, or **(2)** access to copy the Corresponding Source from a network server at no +charge. +* **c)** Convey individual copies of the object code with a copy of the written offer to +provide the Corresponding Source. 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For a particular product received by a +particular user, “normally used” refers to a typical or common use of +that class of product, regardless of the status of the particular user or of the way +in which the particular user actually uses, or expects or is expected to use, the +product. A product is a consumer product regardless of whether the product has +substantial commercial, industrial or non-consumer uses, unless such uses represent +the only significant mode of use of the product. + +“Installation Information” for a User Product means any methods, +procedures, authorization keys, or other information required to install and execute +modified versions of a covered work in that User Product from a modified version of +its Corresponding Source. The information must suffice to ensure that the continued +functioning of the modified object code is in no case prevented or interfered with +solely because modification has been made. + +If you convey an object code work under this section in, or with, or specifically for +use in, a User Product, and the conveying occurs as part of a transaction in which +the right of possession and use of the User Product is transferred to the recipient +in perpetuity or for a fixed term (regardless of how the transaction is +characterized), the Corresponding Source conveyed under this section must be +accompanied by the Installation Information. But this requirement does not apply if +neither you nor any third party retains the ability to install modified object code +on the User Product (for example, the work has been installed in ROM). + +The requirement to provide Installation Information does not include a requirement to +continue to provide support service, warranty, or updates for a work that has been +modified or installed by the recipient, or for the User Product in which it has been +modified or installed. Access to a network may be denied when the modification itself +materially and adversely affects the operation of the network or violates the rules +and protocols for communication across the network. + +Corresponding Source conveyed, and Installation Information provided, in accord with +this section must be in a format that is publicly documented (and with an +implementation available to the public in source code form), and must require no +special password or key for unpacking, reading or copying. + +### 7. Additional Terms + +“Additional permissions” are terms that supplement the terms of this +License by making exceptions from one or more of its conditions. Additional +permissions that are applicable to the entire Program shall be treated as though they +were included in this License, to the extent that they are valid under applicable +law. If additional permissions apply only to part of the Program, that part may be +used separately under those permissions, but the entire Program remains governed by +this License without regard to the additional permissions. + +When you convey a copy of a covered work, you may at your option remove any +additional permissions from that copy, or from any part of it. (Additional +permissions may be written to require their own removal in certain cases when you +modify the work.) You may place additional permissions on material, added by you to a +covered work, for which you have or can give appropriate copyright permission. + +Notwithstanding any other provision of this License, for material you add to a +covered work, you may (if authorized by the copyright holders of that material) +supplement the terms of this License with terms: + +* **a)** Disclaiming warranty or limiting liability differently from the terms of +sections 15 and 16 of this License; or +* **b)** Requiring preservation of specified reasonable legal notices or author +attributions in that material or in the Appropriate Legal Notices displayed by works +containing it; or +* **c)** Prohibiting misrepresentation of the origin of that material, or requiring that +modified versions of such material be marked in reasonable ways as different from the +original version; or +* **d)** Limiting the use for publicity purposes of names of licensors or authors of the +material; or +* **e)** Declining to grant rights under trademark law for use of some trade names, +trademarks, or service marks; or +* **f)** Requiring indemnification of licensors and authors of that material by anyone +who conveys the material (or modified versions of it) with contractual assumptions of +liability to the recipient, for any liability that these contractual assumptions +directly impose on those licensors and authors. + +All other non-permissive additional terms are considered “further +restrictions” within the meaning of section 10. If the Program as you received +it, or any part of it, contains a notice stating that it is governed by this License +along with a term that is a further restriction, you may remove that term. If a +license document contains a further restriction but permits relicensing or conveying +under this License, you may add to a covered work material governed by the terms of +that license document, provided that the further restriction does not survive such +relicensing or conveying. + +If you add terms to a covered work in accord with this section, you must place, in +the relevant source files, a statement of the additional terms that apply to those +files, or a notice indicating where to find the applicable terms. + +Additional terms, permissive or non-permissive, may be stated in the form of a +separately written license, or stated as exceptions; the above requirements apply +either way. + +### 8. Termination + +You may not propagate or modify a covered work except as expressly provided under +this License. Any attempt otherwise to propagate or modify it is void, and will +automatically terminate your rights under this License (including any patent licenses +granted under the third paragraph of section 11). + +However, if you cease all violation of this License, then your license from a +particular copyright holder is reinstated **(a)** provisionally, unless and until the +copyright holder explicitly and finally terminates your license, and **(b)** permanently, +if the copyright holder fails to notify you of the violation by some reasonable means +prior to 60 days after the cessation. + +Moreover, your license from a particular copyright holder is reinstated permanently +if the copyright holder notifies you of the violation by some reasonable means, this +is the first time you have received notice of violation of this License (for any +work) from that copyright holder, and you cure the violation prior to 30 days after +your receipt of the notice. + +Termination of your rights under this section does not terminate the licenses of +parties who have received copies or rights from you under this License. If your +rights have been terminated and not permanently reinstated, you do not qualify to +receive new licenses for the same material under section 10. + +### 9. Acceptance Not Required for Having Copies + +You are not required to accept this License in order to receive or run a copy of the +Program. Ancillary propagation of a covered work occurring solely as a consequence of +using peer-to-peer transmission to receive a copy likewise does not require +acceptance. However, nothing other than this License grants you permission to +propagate or modify any covered work. These actions infringe copyright if you do not +accept this License. Therefore, by modifying or propagating a covered work, you +indicate your acceptance of this License to do so. + +### 10. Automatic Licensing of Downstream Recipients + +Each time you convey a covered work, the recipient automatically receives a license +from the original licensors, to run, modify and propagate that work, subject to this +License. You are not responsible for enforcing compliance by third parties with this +License. + +An “entity transaction” is a transaction transferring control of an +organization, or substantially all assets of one, or subdividing an organization, or +merging organizations. If propagation of a covered work results from an entity +transaction, each party to that transaction who receives a copy of the work also +receives whatever licenses to the work the party's predecessor in interest had or +could give under the previous paragraph, plus a right to possession of the +Corresponding Source of the work from the predecessor in interest, if the predecessor +has it or can get it with reasonable efforts. + +You may not impose any further restrictions on the exercise of the rights granted or +affirmed under this License. For example, you may not impose a license fee, royalty, +or other charge for exercise of rights granted under this License, and you may not +initiate litigation (including a cross-claim or counterclaim in a lawsuit) alleging +that any patent claim is infringed by making, using, selling, offering for sale, or +importing the Program or any portion of it. + +### 11. Patents + +A “contributor” is a copyright holder who authorizes use under this +License of the Program or a work on which the Program is based. The work thus +licensed is called the contributor's “contributor version”. + +A contributor's “essential patent claims” are all patent claims owned or +controlled by the contributor, whether already acquired or hereafter acquired, that +would be infringed by some manner, permitted by this License, of making, using, or +selling its contributor version, but do not include claims that would be infringed +only as a consequence of further modification of the contributor version. For +purposes of this definition, “control” includes the right to grant patent +sublicenses in a manner consistent with the requirements of this License. + +Each contributor grants you a non-exclusive, worldwide, royalty-free patent license +under the contributor's essential patent claims, to make, use, sell, offer for sale, +import and otherwise run, modify and propagate the contents of its contributor +version. + +In the following three paragraphs, a “patent license” is any express +agreement or commitment, however denominated, not to enforce a patent (such as an +express permission to practice a patent or covenant not to sue for patent +infringement). To “grant” such a patent license to a party means to make +such an agreement or commitment not to enforce a patent against the party. + +If you convey a covered work, knowingly relying on a patent license, and the +Corresponding Source of the work is not available for anyone to copy, free of charge +and under the terms of this License, through a publicly available network server or +other readily accessible means, then you must either **(1)** cause the Corresponding +Source to be so available, or **(2)** arrange to deprive yourself of the benefit of the +patent license for this particular work, or **(3)** arrange, in a manner consistent with +the requirements of this License, to extend the patent license to downstream +recipients. “Knowingly relying” means you have actual knowledge that, but +for the patent license, your conveying the covered work in a country, or your +recipient's use of the covered work in a country, would infringe one or more +identifiable patents in that country that you have reason to believe are valid. + +If, pursuant to or in connection with a single transaction or arrangement, you +convey, or propagate by procuring conveyance of, a covered work, and grant a patent +license to some of the parties receiving the covered work authorizing them to use, +propagate, modify or convey a specific copy of the covered work, then the patent +license you grant is automatically extended to all recipients of the covered work and +works based on it. + +A patent license is “discriminatory” if it does not include within the +scope of its coverage, prohibits the exercise of, or is conditioned on the +non-exercise of one or more of the rights that are specifically granted under this +License. You may not convey a covered work if you are a party to an arrangement with +a third party that is in the business of distributing software, under which you make +payment to the third party based on the extent of your activity of conveying the +work, and under which the third party grants, to any of the parties who would receive +the covered work from you, a discriminatory patent license **(a)** in connection with +copies of the covered work conveyed by you (or copies made from those copies), or **(b)** +primarily for and in connection with specific products or compilations that contain +the covered work, unless you entered into that arrangement, or that patent license +was granted, prior to 28 March 2007. + +Nothing in this License shall be construed as excluding or limiting any implied +license or other defenses to infringement that may otherwise be available to you +under applicable patent law. + +### 12. No Surrender of Others' Freedom + +If conditions are imposed on you (whether by court order, agreement or otherwise) +that contradict the conditions of this License, they do not excuse you from the +conditions of this License. If you cannot convey a covered work so as to satisfy +simultaneously your obligations under this License and any other pertinent +obligations, then as a consequence you may not convey it at all. For example, if you +agree to terms that obligate you to collect a royalty for further conveying from +those to whom you convey the Program, the only way you could satisfy both those terms +and this License would be to refrain entirely from conveying the Program. + +### 13. Use with the GNU Affero General Public License + +Notwithstanding any other provision of this License, you have permission to link or +combine any covered work with a work licensed under version 3 of the GNU Affero +General Public License into a single combined work, and to convey the resulting work. +The terms of this License will continue to apply to the part which is the covered +work, but the special requirements of the GNU Affero General Public License, section +13, concerning interaction through a network will apply to the combination as such. + +### 14. Revised Versions of this License + +The Free Software Foundation may publish revised and/or new versions of the GNU +General Public License from time to time. Such new versions will be similar in spirit +to the present version, but may differ in detail to address new problems or concerns. + +Each version is given a distinguishing version number. If the Program specifies that +a certain numbered version of the GNU General Public License “or any later +version” applies to it, you have the option of following the terms and +conditions either of that numbered version or of any later version published by the +Free Software Foundation. If the Program does not specify a version number of the GNU +General Public License, you may choose any version ever published by the Free +Software Foundation. + +If the Program specifies that a proxy can decide which future versions of the GNU +General Public License can be used, that proxy's public statement of acceptance of a +version permanently authorizes you to choose that version for the Program. + +Later license versions may give you additional or different permissions. However, no +additional obligations are imposed on any author or copyright holder as a result of +your choosing to follow a later version. + +### 15. Disclaimer of Warranty + +THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. +EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES +PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER +EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE +QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE +DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. + +### 16. Limitation of Liability + +IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY +COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS +PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, +INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE +PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE +OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE +WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE +POSSIBILITY OF SUCH DAMAGES. + +### 17. Interpretation of Sections 15 and 16 + +If the disclaimer of warranty and limitation of liability provided above cannot be +given local legal effect according to their terms, reviewing courts shall apply local +law that most closely approximates an absolute waiver of all civil liability in +connection with the Program, unless a warranty or assumption of liability accompanies +a copy of the Program in return for a fee. + +_END OF TERMS AND CONDITIONS_ + +## How to Apply These Terms to Your New Programs + +If you develop a new program, and you want it to be of the greatest possible use to +the public, the best way to achieve this is to make it free software which everyone +can redistribute and change under these terms. + +To do so, attach the following notices to the program. It is safest to attach them +to the start of each source file to most effectively state the exclusion of warranty; +and each file should have at least the “copyright” line and a pointer to +where the full notice is found. + + + Copyright (C) + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . + +Also add information on how to contact you by electronic and paper mail. + +If the program does terminal interaction, make it output a short notice like this +when it starts in an interactive mode: + + Copyright (C) + This program comes with ABSOLUTELY NO WARRANTY; for details type 'show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type 'show c' for details. + +The hypothetical commands `show w` and `show c` should show the appropriate parts of +the General Public License. Of course, your program's commands might be different; +for a GUI interface, you would use an “about box”. + +You should also get your employer (if you work as a programmer) or school, if any, to +sign a “copyright disclaimer” for the program, if necessary. For more +information on this, and how to apply and follow the GNU GPL, see +<>. + +The GNU General Public License does not permit incorporating your program into +proprietary programs. If your program is a subroutine library, you may consider it +more useful to permit linking proprietary applications with the library. If this is +what you want to do, use the GNU Lesser General Public License instead of this +License. But first, please read +<>. diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..a12690e --- /dev/null +++ b/Makefile @@ -0,0 +1,6 @@ +.PHONY: image + +image: + docker build --tag simple-chat-server . + + diff --git a/client/chat.js b/client/chat.js new file mode 100644 index 0000000..6736b56 --- /dev/null +++ b/client/chat.js @@ -0,0 +1,126 @@ +const saltSize = 16; // recommended size for salt used in password derivation functions +const ivSize = 12; // size for initial value array per AES GCM specification +const iterationNum = 10000; // lowest recommendable number of iterations for password derivation + +// conversion functions +function arrayBufferToArray(buf) { + return new Uint8Array(buf); +} +function arrayToBase64(arr) { + return btoa(String.fromCharCode.apply(null, arr)); +}; +function base64ToArray(b64) { + return Uint8Array.from(atob(b64), (c) => c.charCodeAt(null)); +}; +function stringToArray(str) { + return new TextEncoder().encode(str); +}; +function arrayToString(arr) { + return new TextDecoder().decode(arr); +}; + +// cryptography +async function password(passwd) { + return window.crypto.subtle.importKey("raw", stringToArray(passwd), "PBKDF2", false, ["deriveKey"]); +}; +async function derive(key, salt) { + return window.crypto.subtle.deriveKey({ name: "PBKDF2", salt: salt, iterations: iterationNum, hash: "SHA-256" }, key, { name: "AES-GCM", length: 256 }, false, ["encrypt", "decrypt"]); +}; +function buildMessage(salt, iv, arr) { + let msg = new Uint8Array(saltSize+ivSize+arr.byteLength); + msg.set(salt, 0); + msg.set(iv, saltSize); + msg.set(arr, saltSize+ivSize); + return arrayToBase64(msg); +}; +async function encrypt(str) { + const salt = window.crypto.getRandomValues(new Uint8Array(saltSize)); + const iv = window.crypto.getRandomValues(new Uint8Array(ivSize)); + + try { + const key = await derive(passkey, salt); + const buf = await window.crypto.subtle.encrypt({ name: "AES-GCM", iv: iv }, key, stringToArray(str)); + return buildMessage(salt, iv, arrayBufferToArray(buf)); + } catch (e) { + console.log("encryption failed"); + return str; + } +}; +async function decrypt(blob) { + const arr = base64ToArray(blob); + const salt = arr.slice(0, saltSize); + const iv = arr.slice(saltSize, saltSize+ivSize); + const msg = arr.slice(saltSize+ivSize); + + try { + const key = await derive(passkey, salt); + const buf = await window.crypto.subtle.decrypt({ name: "AES-GCM", iv: iv }, key, msg); + return arrayToString(arrayBufferToArray(buf)); + } catch (e) { + console.log("decryption failed"); + return blob; + } +}; + +function escapeHTML(str) { + return str.replaceAll('&', '&').replaceAll('<', '<').replaceAll('>', '>').replaceAll('"', '"').replaceAll("'", '''); +}; + +// initialize passkey to null +var passkey; + +function connect() { + socket = new WebSocket('wss://api.dominic-ricottone.com/chat'); + + // On close, reconnect after 1s (=1000ms) + socket.onclose = () => { + setTimeout(connect, 1000); + }; + + socket.onmessage = async (m) => { + const el = document.createElement('li'); + if (passkey == null) { + el.innerHTML = escapeHTML(m.data); + } else { + const decrypted = await decrypt(m.data); + el.innerHTML = escapeHTML(decrypted); + } + document.getElementById('chat-room').appendChild(el); + }; +}; + +// try to initialize socket to a connection +var socket; +connect(); + +document.addEventListener("DOMContentLoaded", () => { + // chat interface + const chatInput = document.getElementById('chat-input'); + const chatButton = document.getElementById('chat-button'); + + chatButton.onclick = async () => { + if (passkey == null) { + socket.send(chatInput.value); + } else { + const encrypted = await encrypt(chatInput.value); + socket.send(encrypted); + } + }; + + chatInput.addEventListener('keyup', (event) => { + if (event.keyCode === 13) { + event.preventDefault(); + chatButton.click(); + } + }); + + // password interface + const passwdInput = document.getElementById('passwd-input'); + const passwdButton = document.getElementById('passwd-button'); + + passwdButton.onclick = async () => { + const key = await password(passwdInput.value); + passkey = key + }; +}); + diff --git a/client/index.html b/client/index.html new file mode 100644 index 0000000..065047d --- /dev/null +++ b/client/index.html @@ -0,0 +1,17 @@ + + + + + + Simple Chat Client + + + + + +
    + + + + + diff --git a/server/.gitignore b/server/.gitignore new file mode 100644 index 0000000..0ea97b0 --- /dev/null +++ b/server/.gitignore @@ -0,0 +1,3 @@ +go.sum +server + diff --git a/server/Makefile b/server/Makefile new file mode 100644 index 0000000..763843a --- /dev/null +++ b/server/Makefile @@ -0,0 +1,9 @@ +.PHONY: clean build + +clean: + rm -f server go.sum + +build: clean + go get -u + go build + diff --git a/server/go.mod b/server/go.mod new file mode 100644 index 0000000..d23c73b --- /dev/null +++ b/server/go.mod @@ -0,0 +1,5 @@ +module git.dominic-ricottone.com/simple-chat/server + +go 1.18 + +require github.com/gorilla/websocket v1.5.0 diff --git a/server/main.go b/server/main.go new file mode 100644 index 0000000..43188af --- /dev/null +++ b/server/main.go @@ -0,0 +1,126 @@ +package main + +import ( + "log" + "net/http" + "time" + + "github.com/gorilla/websocket" +) + +type Client struct { + chatroom *Chatroom + conn *websocket.Conn + id int + queue chan []byte +} + +func (client *Client) read() { + defer func() { + client.chatroom.kill <- client + client.conn.Close() + }() + + for { + //NOTE: not using msg type + _, msg, err := client.conn.ReadMessage() + if err != nil { + if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure) { + log.Println("while reading message:", err) + } + break + } + client.chatroom.queue <-msg + } +} + +func (client *Client) write() { + ticker := time.NewTicker(60 * time.Second) + + defer func() { + ticker.Stop() + client.chatroom.kill <-client + client.conn.Close() + }() + + for { + select { + case msg := <-client.queue: + err := client.conn.WriteMessage(websocket.TextMessage, msg) + if err != nil { + log.Println("while writing message:", err) + break + } + case <-ticker.C: + //TODO: add keep-alive ping w/ client.conn.PingMessage + } + } +} + +type Chatroom struct { + clients map[*Client]bool + queue chan []byte + kill chan *Client +} + +func (chatroom *Chatroom) introduce(conn *websocket.Conn) *Client { + client := &Client{ + chatroom: chatroom, + conn: conn, + id: len(chatroom.clients), + queue: make(chan []byte), + } + chatroom.clients[client] = true + return client +} + +func (chatroom *Chatroom) run() { + for { + select { + case dead := <-chatroom.kill: + delete(chatroom.clients, dead) + case msg := <-chatroom.queue: + for client := range chatroom.clients { + client.queue <-msg + } + } + } +} + +func main() { + // Run chatroom + chatroom := &Chatroom{ + clients: make(map[*Client]bool), + queue: make(chan []byte), + kill: make(chan *Client), + } + go chatroom.run() + + // Configure websocket upgrader + upgrader := websocket.Upgrader{ + CheckOrigin: func(r *http.Request) bool { + origin := r.Header.Get("Origin") + return origin == "https://www.dominic-ricottone.com" + }, + } + + // Handler for new connections + http.HandleFunc("/chat", func(w http.ResponseWriter, r *http.Request) { + conn, err := upgrader.Upgrade(w, r, nil) + if err != nil { + log.Println("while upgrading connection:", err) + return + } + + client := chatroom.introduce(conn) + go client.read() + go client.write() + }) + + // Run server + err := http.ListenAndServe(":40080", nil) + if err != nil { + log.Println("while running server:", err) + } +} + -- 2.45.2