feat: Initial clean release of CHM

packages/app-mobile/services/e2ee/RSA.react-native.ts

@@ -0,0 +1,97 @@
+import buildRsaCryptoProvider from '@joplin/lib/services/e2ee/ppk/webCrypto/buildRsaCryptoProvider';
+import { WebCryptoSlice } from '@joplin/lib/services/e2ee/ppk/webCrypto/WebCryptoRsa';
+import { CiphertextBuffer, PublicKeyAlgorithm, PublicKeyCrypto, PublicKeyCryptoProvider } from '@joplin/lib/services/e2ee/types';
+import QuickCrypto from 'react-native-quick-crypto';
+const RnRSA = require('react-native-rsa-native').RSA;
+
+interface LegacyRsaKeyPair {
+	public: string;
+	private: string;
+	keySizeBits: number;
+}
+
+const legacyRsa: PublicKeyCrypto = {
+	generateKeyPair: async () => {
+		const keySize = 2048;
+		const keys: LegacyRsaKeyPair = await RnRSA.generateKeys(keySize);
+
+		// Sanity check
+		if (!keys.private) throw new Error('No private key was generated');
+		if (!keys.public) throw new Error('No public key was generated');
+
+		const keyPair = await legacyRsa.loadKeys(keys.public, keys.private, keySize);
+		return {
+			keyPair,
+			keySize,
+		};
+	},
+
+	maximumPlaintextLengthBytes: 190,
+
+	loadKeys: async (publicKey: string, privateKey: string, keySizeBits: number): Promise<LegacyRsaKeyPair> => {
+		return { public: publicKey, private: privateKey, keySizeBits };
+	},
+
+	encrypt: async (plaintextUtf8: string, rsaKeyPair: LegacyRsaKeyPair) => {
+		// TODO: Support long-data encryption in a way compatible with node-rsa.
+		return Buffer.from(await RnRSA.encrypt(plaintextUtf8, rsaKeyPair.public), 'base64');
+	},
+
+	decrypt: async (ciphertextBuffer: CiphertextBuffer, rsaKeyPair: LegacyRsaKeyPair): Promise<string> => {
+		const maximumEncryptedSize = Math.floor(rsaKeyPair.keySizeBits / 8); // Usually 256
+
+		// On iOS, .decrypt fails without throwing or rejecting.
+		// This function throws for consistency with Android.
+		const handleError = (plainText: string|undefined) => {
+			if (plainText === undefined) {
+				throw new Error(`
+					RN RSA: Decryption failed.
+						cipherTextLength=${ciphertextBuffer.length},
+						maxEncryptedSize=${maximumEncryptedSize}
+				`.trim());
+			}
+		};
+
+		// Master keys are encrypted with RSA and are longer than the default modulus size of 256 bytes.
+		// node-rsa supports encrypting larger amounts of data using RSA.
+		// See their implementation for details: https://github.com/rzcoder/node-rsa/blob/e7e7f7d2942a3bac1d2e132a881e5a3aceda10a1/src/libs/rsa.js#L252
+		if (ciphertextBuffer.length > maximumEncryptedSize) {
+			// Use a numBlocks and blockSize that match node-rsa:
+			const numBlocks = Math.ceil(ciphertextBuffer.length / maximumEncryptedSize);
+			const blockSize = maximumEncryptedSize;
+
+			const result: string[] = [];
+			for (let i = 0; i < numBlocks; i++) {
+				const ciphertextBlock = ciphertextBuffer.slice(
+					i * blockSize, Math.min(ciphertextBuffer.length, (i + 1) * blockSize),
+				);
+				const plainText = await RnRSA.decrypt(ciphertextBlock.toString('base64'), rsaKeyPair.private);
+
+				handleError(plainText);
+				result.push(plainText);
+			}
+			return result.join('');
+		} else {
+			const plainText = await RnRSA.decrypt(ciphertextBuffer.toString('base64'), rsaKeyPair.private);
+			handleError(plainText);
+			return plainText;
+		}
+	},
+
+	publicKey: async (rsaKeyPair: LegacyRsaKeyPair) => {
+		return rsaKeyPair.public;
+	},
+
+	privateKey: async (rsaKeyPair: LegacyRsaKeyPair) => {
+		return rsaKeyPair.private;
+	},
+};
+
+const rsa: PublicKeyCryptoProvider = {
+	[PublicKeyAlgorithm.Unknown]: null,
+	[PublicKeyAlgorithm.RsaV1]: legacyRsa,
+	[PublicKeyAlgorithm.RsaV2]: buildRsaCryptoProvider(PublicKeyAlgorithm.RsaV2, QuickCrypto as WebCryptoSlice),
+	[PublicKeyAlgorithm.RsaV3]: buildRsaCryptoProvider(PublicKeyAlgorithm.RsaV3, QuickCrypto as WebCryptoSlice),
+};
+
+export default rsa;