Encrypted, ephemeral, private memos on atproto
init with basic lexicon schemas
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+15
README.md
+15
README.md
···
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# Cistern
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Cistern is an attempt at implementing a private, personal quick-capture system
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on AT Protocol. Cistern "items" are encrypted, so that they are only readable
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by the holder of the correct secret key—stored off-protocol. These items are
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intended to be ephemeral, and to be deleted after they've been read.
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The intention is for Cistern to bridge the gap between where ideas are had and
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where they can be stored long-term. For example, let's say you have an idea
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while at a restaurant. You create an item using your phone, and once you're
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back at your desk and you open Obsidian, that item is automatically pulled from
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your PDS, decrypted, and deleted from your PDS. If your notebook was open at
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the time you created your item, the Cistern Obsidian plugin would have been
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notified of the new item via the Jetstream, and so you would find your memo
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waiting for you once you got home.
+57
deno.lock
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deno.lock
···
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{
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"version": "5",
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"specifiers": {
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"npm:@atproto/lexicon@~0.5.1": "0.5.1"
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},
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"npm": {
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"@atproto/common-web@0.4.3": {
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"integrity": "sha512-nRDINmSe4VycJzPo6fP/hEltBcULFxt9Kw7fQk6405FyAWZiTluYHlXOnU7GkQfeUK44OENG1qFTBcmCJ7e8pg==",
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"dependencies": [
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"graphemer",
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"multiformats",
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"uint8arrays",
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"zod"
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]
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},
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"@atproto/lexicon@0.5.1": {
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"integrity": "sha512-y8AEtYmfgVl4fqFxqXAeGvhesiGkxiy3CWoJIfsFDDdTlZUC8DFnZrYhcqkIop3OlCkkljvpSJi1hbeC1tbi8A==",
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"dependencies": [
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"@atproto/common-web",
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"@atproto/syntax",
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"iso-datestring-validator",
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"multiformats",
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"zod"
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]
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},
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"@atproto/syntax@0.4.1": {
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"integrity": "sha512-CJdImtLAiFO+0z3BWTtxwk6aY5w4t8orHTMVJgkf++QRJWTxPbIFko/0hrkADB7n2EruDxDSeAgfUGehpH6ngw=="
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},
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"graphemer@1.4.0": {
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"integrity": "sha512-EtKwoO6kxCL9WO5xipiHTZlSzBm7WLT627TqC/uVRd0HKmq8NXyebnNYxDoBi7wt8eTWrUrKXCOVaFq9x1kgag=="
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},
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"iso-datestring-validator@2.2.2": {
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"integrity": "sha512-yLEMkBbLZTlVQqOnQ4FiMujR6T4DEcCb1xizmvXS+OxuhwcbtynoosRzdMA69zZCShCNAbi+gJ71FxZBBXx1SA=="
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},
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"multiformats@9.9.0": {
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"integrity": "sha512-HoMUjhH9T8DDBNT+6xzkrd9ga/XiBI4xLr58LJACwK6G3HTOPeMz4nB4KJs33L2BelrIJa7P0VuNaVF3hMYfjg=="
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},
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"uint8arrays@3.0.0": {
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"integrity": "sha512-HRCx0q6O9Bfbp+HHSfQQKD7wU70+lydKVt4EghkdOvlK/NlrF90z+eXV34mUd48rNvVJXwkrMSPpCATkct8fJA==",
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"dependencies": [
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"multiformats"
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]
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},
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"zod@3.25.76": {
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"integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ=="
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}
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},
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"workspace": {
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"members": {
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"packages/lexicon": {
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"dependencies": [
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"npm:@atproto/lexicon@~0.5.1"
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]
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}
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}
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}
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}
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packages/lexicon/deno.jsonc
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packages/lexicon/deno.jsonc
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packages/lexicon/mod.ts
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packages/lexicon/mod.ts
···
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import item from "./schemas/item.json" with { type: "json" };
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import pubkey from "./schemas/pubkey.json" with { type: "json" };
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import { Lexicons } from "@atproto/lexicon";
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const lexicons = new Lexicons();
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lexicons.add(item);
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lexicons.add(pubkey);
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export { item, lexicons, pubkey };
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packages/lexicon/schemas/item.json
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packages/lexicon/schemas/item.json
···
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{
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"version": 1,
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"id": "app.cistern.lexicon.item",
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"description": "An encrypted value meant to be accessed and deleted later.",
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"defs": {
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"encryptedField": {
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"type": "object",
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"description": "An inline-encrypted property",
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"required": ["value", "nonce"],
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"properties": {
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"value": {
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"type": "string",
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"description": "Encrypted field value"
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},
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"nonce": {
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"type": "string",
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"description": "Nonce used to encrypt field value"
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}
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}
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},
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"main": {
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"type": "record",
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"description": "A manifest representing an encrypted note or binary file",
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"record": {
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"type": "object",
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"required": [
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"tid",
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"ciphertext",
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"nonce",
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"algorithm",
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"pubkey",
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"chunks",
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"metadata"
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],
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"properties": {
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"tid": {
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"type": "string",
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"description": "TID representing when this item was created",
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"format": "tid"
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}
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"ciphertext": {
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"type": "string",
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"description": "Encapsulated shared ciphertext"
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},
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"nonce": {
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"type": "string",
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"description": "Nonce used for content encryption",
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"maxLength": 64,
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},
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"algorithm": {
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"type": "string",
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"description": "Algorithm used for encryption, in <kem>-<cipher>-<hash> format.",
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"knownValues": ["x_wing-xchacha20_poly1305-sha3_512"]
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},
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"pubkey": {
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"type": "string",
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"description": "URI to the public key used to encrypt this item",
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"format": "at-uri"
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},
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"chunks": {
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"type": "array",
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"description": "Encrypted blobs that compose the encrypted contents of the item"
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"items": {
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"type": "blob",
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"accept": "application/octet-stream",
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"maxSize": 50000000
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},
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"minLength": 1
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},
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"metadata": {
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"type": "object",
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"description": "Information about the encrypted content.",
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"required": ["format", "length", "hash"],
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"properties": {
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"format": {
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"type": "string",
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"description": "Original contents format",
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"knownValues": ["text", "file"]
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},
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"length": {
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"type": "ref",
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"description": "Original content length in bytes",
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"ref": "app.cistern.lexicon.item#encryptedField"
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},
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"hash": {
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"type": "string",
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"description": "SHA-256 hash of the original file",
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"maxLength": 64,
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},
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"mimetype": {
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"type": "ref",
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"description": "Mimetype of original contents, if a file",
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"ref": "app.cistern.lexicon.item#encryptedField"
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}
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}
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}
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}
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}
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}
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}
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}
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packages/lexicon/schemas/pubkey.json
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packages/lexicon/schemas/pubkey.json
···
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{
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"version": 1,
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"id": "app.cistern.lexicon.pubkey",
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"description": "A public key used to encrypt Cistern items",
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"defs": {
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"main": {
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"type": "record",
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"description": "A public key used to encrypt Cistern items",
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"record": {
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"type": "object",
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"required": ["name", "algorithm", "content", "createdAt"],
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"properties": {
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"name": {
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"type": "string",
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"minGraphemes": 1,
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"description": "A memorable name for this public key. Avoid using revealing names, such as \"Graham's Macbook\""
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},
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"algorithm": {
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"type": "string",
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"knownValues": ["x_wing"],
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"description": "KEM algorithm used to generate this key"
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},
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"content": {
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"type": "string",
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"description": "Contents of the public key, encoded in base64"
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},
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"createdAt": {
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"type": "string",
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"format": "datetime"
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}
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}
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}
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}
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}
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}