feat: private key formats

src/handlers/generate-erc20-permit.ts

@@ -2,7 +2,7 @@ import { PERMIT2_ADDRESS, PermitTransferFrom, SignatureTransfer } from "@uniswap
 import { ethers, keccak256, MaxInt256, parseUnits, toUtf8Bytes } from "ethers";
 import { Context, Logger } from "../types/context";
 import { PermitReward, TokenType } from "../types";
-import { decryptKeys } from "../utils";
+import { decrypt, parseDecryptedPrivateKey } from "../utils";
 import { getFastestProvider } from "../utils/get-fastest-provider";
 
 export interface Payload {
@@ -74,10 +74,15 @@ export async function generateErc20PermitSignature(
     throw new Error("Provider is not defined");
   }
 
-  const { privateKey } = await decryptKeys(_evmPrivateEncrypted);
-  if (!privateKey) {
-    const errorMessage = "Private key is not defined";
-    _logger.fatal(errorMessage);
+  let privateKey = null;
+  try {
+    const privateKeyDecrypted = await decrypt(_evmPrivateEncrypted, String(process.env.X25519_PRIVATE_KEY));
+    const privateKeyParsed = parseDecryptedPrivateKey(privateKeyDecrypted);
+    privateKey = privateKeyParsed.privateKey;
+    if (!privateKey) throw new Error("Private key is not defined");
+  } catch (error) {
+    const errorMessage = `Failed to decrypt a private key: ${error}`;
+    _logger.error(errorMessage);
     throw new Error(errorMessage);
   }
 

src/index.ts

@@ -2,3 +2,4 @@ export * from "./handlers";
 export * from "./adapters";
 export * from "./generate-permits-from-context";
 export * from "./types";
+export * from "./utils";

src/utils/keys.ts

@@ -1,40 +1,101 @@
 import sodium from "libsodium-wrappers";
-const KEY_PREFIX = "HSK_";
 
-export async function decryptKeys(cipherText: string): Promise<{ privateKey: string; publicKey: string } | { privateKey: null; publicKey: null }> {
+/**
+ * Decrypts encrypted text with provided "X25519_PRIVATE_KEY" value
+ * @param encryptedText Encrypted text
+ * @param x25519PrivateKey "X25519_PRIVATE_KEY" private key
+ * @returns Decrypted text
+ */
+export async function decrypt(encryptedText: string, x25519PrivateKey: string): Promise<string> {
   await sodium.ready;
 
-  let _public: null | string = null;
-  let _private: null | string = null;
+  const publicKey = await getPublicKey(x25519PrivateKey);
+
+  const binaryPublic = sodium.from_base64(publicKey, sodium.base64_variants.URLSAFE_NO_PADDING);
+  const binaryPrivate = sodium.from_base64(x25519PrivateKey, sodium.base64_variants.URLSAFE_NO_PADDING);
+  const binaryEncryptedText = sodium.from_base64(encryptedText, sodium.base64_variants.URLSAFE_NO_PADDING);
 
-  const X25519_PRIVATE_KEY = process.env.X25519_PRIVATE_KEY;
+  const decryptedText = sodium.crypto_box_seal_open(binaryEncryptedText, binaryPublic, binaryPrivate, "text");
 
-  if (!X25519_PRIVATE_KEY) {
-    console.warn("X25519_PRIVATE_KEY is not defined");
-    return { privateKey: null, publicKey: null };
-  }
-  _public = await getScalarKey(X25519_PRIVATE_KEY);
-  if (!_public) {
-    console.warn("Public key is null");
-    return { privateKey: null, publicKey: null };
-  }
-  if (!cipherText?.length) {
-    console.warn("No cipherText was provided");
-    return { privateKey: null, publicKey: null };
-  }
-  const binaryPublic = sodium.from_base64(_public, sodium.base64_variants.URLSAFE_NO_PADDING);
-  const binaryPrivate = sodium.from_base64(X25519_PRIVATE_KEY, sodium.base64_variants.URLSAFE_NO_PADDING);
+  return decryptedText;
+}
 
-  const binaryCipher = sodium.from_base64(cipherText, sodium.base64_variants.URLSAFE_NO_PADDING);
+/**
+ * Returns public key from provided "X25519_PRIVATE_KEY" value
+ * @param x25519PrivateKey "X25519_PRIVATE_KEY" private key
+ * @returns Public key
+ */
+export async function getPublicKey(x25519PrivateKey: string): Promise<string> {
+  await sodium.ready;
+  const binaryPrivate = sodium.from_base64(x25519PrivateKey, sodium.base64_variants.URLSAFE_NO_PADDING);
+  return sodium.crypto_scalarmult_base(binaryPrivate, "base64");
+}
 
-  const walletPrivateKey: string | null = sodium.crypto_box_seal_open(binaryCipher, binaryPublic, binaryPrivate, "text");
-  _private = walletPrivateKey?.replace(KEY_PREFIX, "");
+/**
+ * Parses partner's private key into object with properties:
+ * 1. Private key
+ * 2. Organization id where this private key is allowed to be used
+ * 3. Repository id where this private key is allowed to be used
+ * 
+ * The issue with "plain" encryption of wallet private keys is that if partner accidentally shares 
+ * his encrypted private key then a malicious user will be able to use that leaked private key 
+ * in another organization with permits generated from a leaked partner's wallet.
+ * 
+ * Partner private key (`evmPrivateEncrypted` config param in `conversation-rewards` plugin) supports 3 formats:
+ * 1. PRIVATE_KEY
+ * 2. PRIVATE_KEY:GITHUB_ORGANIZATION_ID
+ * 3. PRIVATE_KEY:GITHUB_ORGANIZATION_ID:GITHUB_REPOSITORY_ID
+ * 
+ * Format "PRIVATE_KEY" can be used only for `ubiquity` and `ubiquibot` organizations. It is
+ * kept for backwards compatibility in order not to update private key formats for our existing
+ * values set in the `evmPrivateEncrypted` param.
+ * 
+ * Format "PRIVATE_KEY:GITHUB_ORGANIZATION_ID" restricts in which particular organization this private
+ * key can be used. It can be set either in the organization wide config either in the repository wide one.
+ * 
+ * Format "PRIVATE_KEY:GITHUB_ORGANIZATION_ID:GITHUB_REPOSITORY_ID" restricts organization and a particular 
+ * repository where private key is allowed to be used.
+ * 
+ * @param decryptedPrivateKey Decrypted private key string (in any of the 3 different formats) 
+ * @returns Parsed private key object: private key, organization id and repository id
+ */
+export function parseDecryptedPrivateKey(decryptedPrivateKey: string) {
+  let result: {
+    privateKey: string | null,
+    allowedOrganizationId: number | null,
+    allowedRepositoryId: number | null,
+  } = {
+    privateKey: null,
+    allowedOrganizationId: null,
+    allowedRepositoryId: null,
+  };
+
+  // split private key
+  const privateKeyParts = decryptedPrivateKey.split(":");
 
-  return { privateKey: _private, publicKey: _public };
-}
+  // Plain private key.
+  // Format: "PRIVATE_KEY".
+  // Used for backwards compatibility with ubiquity related organizations:
+  // - https://github.com/ubiquity
+  // - https://github.com/ubiquibot
+  if (privateKeyParts.length === 1) {
+    result.privateKey = privateKeyParts[0];
+  }
 
-async function getScalarKey(x25519PrivateKey: string) {
-  await sodium.ready;
-  const binPriv = sodium.from_base64(x25519PrivateKey, sodium.base64_variants.URLSAFE_NO_PADDING);
-  return sodium.crypto_scalarmult_base(binPriv, "base64");
+  // Private key + allowed organization id.
+  // Format: "PRIVATE_KEY:GITHUB_ORGANIZATION_ID"
+  if (privateKeyParts.length === 2) {
+    result.privateKey = privateKeyParts[0];
+    result.allowedOrganizationId = Number(privateKeyParts[1]);
+  }
+
+  // Private key + allowed organization id + allowed repository id.
+  // Format: "PRIVATE_KEY:GITHUB_ORGANIZATION_ID:GITHUB_REPOSITORY_ID"
+  if (privateKeyParts.length === 3) {
+    result.privateKey = privateKeyParts[0];
+    result.allowedOrganizationId = Number(privateKeyParts[1]);
+    result.allowedRepositoryId = Number(privateKeyParts[2]);
+  }
+
+  return result;
 }

tests/generate-erc20-permit.test.ts

@@ -76,9 +76,9 @@ describe("generateErc20PermitSignature", () => {
 
   it("should throw error when evmPrivateEncrypted is not defined", async () => {
     const amount = 0;
-
-    await expect(generateErc20PermitSignature(context, SPENDER, amount, ERC20_REWARD_TOKEN_ADDRESS)).rejects.toThrow("Private key is not defined");
-    expect(context.logger.fatal).toHaveBeenCalledWith("Private key is not defined");
+    const expectedError = "Failed to decrypt a private key: TypeError: input cannot be null or undefined";
+    await expect(generateErc20PermitSignature(context, SPENDER, amount, ERC20_REWARD_TOKEN_ADDRESS)).rejects.toThrow(expectedError);
+    expect(context.logger.error).toHaveBeenCalledWith(expectedError);
   });
 
   it("should return error message when no wallet found for user", async () => {

tests/utils/keys.test.ts

@@ -0,0 +1,61 @@
+import { describe, expect, it } from "@jest/globals";
+import { decrypt, getPublicKey, parseDecryptedPrivateKey } from "../../src/utils";
+
+// dummy value for testing purposes
+const X25519_PRIVATE_KEY = "wrQ9wTI1bwdAHbxk2dfsvoK1yRwDc0CEenmMXFvGYgY";
+
+describe("keys", () => {
+  describe("decrypt()", () => {
+    it("Should decrypt encrypted text", async () => {
+      // encrypted "test"
+      const encryptedText = 'RZcKYqzwb6zeRHCJcV5QxGKrNPEll-xyRW_bNNa2rw3bddnjX2Kd-ycPvGq1NocSAHJR2w';
+      const decryptedText = await decrypt(encryptedText, X25519_PRIVATE_KEY);
+      expect(decryptedText).toEqual('test');
+    });
+  });
+
+  describe("getPublicKey()", () => {
+    it("Should return public key from private key", async () => {
+      const publicKey = await getPublicKey(X25519_PRIVATE_KEY);
+      expect(publicKey).toEqual('iHYr7Zy077eoAvunTB_-DQIq5Nz73H_nIYaS_buiQjo');
+    });
+  });
+
+  describe("parseDecryptedPrivateKey()", () => {
+    it("Should return parsed private key for format PRIVATE_KEY", async () => {
+      // encrypted "test"
+      const encryptedText = 'RZcKYqzwb6zeRHCJcV5QxGKrNPEll-xyRW_bNNa2rw3bddnjX2Kd-ycPvGq1NocSAHJR2w';
+      const decryptedText = await decrypt(encryptedText, X25519_PRIVATE_KEY);
+      const parsedPrivateKey = parseDecryptedPrivateKey(decryptedText);
+      expect(parsedPrivateKey).toEqual({
+        privateKey: "test",
+        allowedOrganizationId: null,
+        allowedRepositoryId: null,
+      });
+    });
+
+    it("Should return parsed private key for format PRIVATE_KEY:GITHUB_ORGANIZATION_ID", async () => {
+      // encrypted "test:1"
+      const encryptedText = '6VWlePw3pf7XED3OXl2C8SBxdZ5i-yj214OI43TaChXhWxNHSQL2wHOyqNXqjcuedKVOW8HC';
+      const decryptedText = await decrypt(encryptedText, X25519_PRIVATE_KEY);
+      const parsedPrivateKey = parseDecryptedPrivateKey(decryptedText);
+      expect(parsedPrivateKey).toEqual({
+        privateKey: "test",
+        allowedOrganizationId: 1,
+        allowedRepositoryId: null,
+      });
+    });
+
+    it("Should return parsed private key for format PRIVATE_KEY:GITHUB_ORGANIZATION_ID:GITHUB_REPOSITORY_ID", async () => {
+      // encrypted "test:1:2"
+      const encryptedText = 'q1yDNgeKQTiztJH8gfKH2cX77eC6BfvaSMjCxl7Q-Fj79LICsNBQOtjOBUXJoUdBqtbvI3OCvuw';
+      const decryptedText = await decrypt(encryptedText, X25519_PRIVATE_KEY);
+      const parsedPrivateKey = parseDecryptedPrivateKey(decryptedText);
+      expect(parsedPrivateKey).toEqual({
+        privateKey: "test",
+        allowedOrganizationId: 1,
+        allowedRepositoryId: 2,
+      });
+    });
+  });
+});