Begin refactoring backfilling and preparation operations into setup and start adding encryption metadata to models

backend/src/utils/crypto/index.ts

@@ -0,0 +1,237 @@
+import crypto from 'crypto';
+import nacl from 'tweetnacl';
+import util from 'tweetnacl-util';
+import { 
+    IGenerateKeyPairOutput,
+    IEncryptAsymmetricInput,
+    IEncryptAsymmetricOutput,
+    IDecryptAsymmetricInput,
+    IEncryptSymmetricInput,
+    IEncryptSymmetricOutput,
+    IDecryptSymmetricInput
+} from '../../interfaces/utils';
+import { 
+    BadRequestError,
+    InternalServerError
+} from '../errors';
+import { 
+    ALGORITHM_AES_256_GCM, 
+    BLOCK_SIZE_BYTES_32,
+    BLOCK_SIZE_BYTES_16
+} from '../../variables';
+import { validateEncryptionKey } from '../../validation';
+
+/**
+ * Return new base64, NaCl, public-private key pair.
+ * @returns {Object} obj
+ * @returns {String} obj.publicKey - (base64) NaCl, public key
+ * @returns {String} obj.privateKey - (base64), NaCl, private key
+ */
+const generateKeyPair = (): IGenerateKeyPairOutput => {
+	const pair = nacl.box.keyPair();
+    
+	return ({
+		publicKey: util.encodeBase64(pair.publicKey),
+		privateKey: util.encodeBase64(pair.secretKey)
+	});
+}
+
+/**
+ * Return assymmetrically encrypted [plaintext] using [publicKey] where
+ * [publicKey] likely belongs to the recipient.
+ * @param {Object} obj
+ * @param {String} obj.plaintext - plaintext to encrypt
+ * @param {String} obj.publicKey - (base64) Nacl public key of the recipient
+ * @param {String} obj.privateKey - (base64) Nacl private key of the sender (current user)
+ * @returns {Object} obj
+ * @returns {String} obj.ciphertext - (base64) ciphertext
+ * @returns {String} obj.nonce - (base64) nonce
+ */
+const encryptAsymmetric = ({
+	plaintext,
+	publicKey,
+	privateKey
+}: IEncryptAsymmetricInput): IEncryptAsymmetricOutput => {
+  const nonce = nacl.randomBytes(24);
+  const ciphertext = nacl.box(
+    util.decodeUTF8(plaintext),
+    nonce,
+    util.decodeBase64(publicKey),
+    util.decodeBase64(privateKey)
+  );
+
+	return {
+		ciphertext: util.encodeBase64(ciphertext),
+		nonce: util.encodeBase64(nonce)
+	};
+};
+
+/**
+ * Return assymmetrically decrypted [ciphertext] using [privateKey] where
+ * [privateKey] likely belongs to the recipient.
+ * @param {Object} obj
+ * @param {String} obj.ciphertext - ciphertext to decrypt
+ * @param {String} obj.nonce - (base64) nonce
+ * @param {String} obj.publicKey - (base64) public key of the sender
+ * @param {String} obj.privateKey - (base64) private key of the receiver (current user)
+ * @returns {String} plaintext - (utf8) plaintext
+ */
+const decryptAsymmetric = ({
+	ciphertext,
+	nonce,
+	publicKey,
+	privateKey
+}: IDecryptAsymmetricInput): string => {
+    const plaintext: Uint8Array | null = nacl.box.open(
+        util.decodeBase64(ciphertext),
+        util.decodeBase64(nonce),
+        util.decodeBase64(publicKey),
+        util.decodeBase64(privateKey)
+    );
+  
+    if (plaintext == null) throw BadRequestError({
+        message: 'Invalid ciphertext or keys'
+    });
+  
+    return util.encodeUTF8(plaintext);
+};
+
+/**
+ * Return symmetrically encrypted [plaintext] using [key].
+ * @param {Object} obj
+ * @param {String} obj.plaintext - (utf8) plaintext to encrypt
+ * @param {String} obj.key - (base64) 256-bit key
+ * @returns {Object} obj
+ * @returns {String} obj.ciphertext (base64) ciphertext
+ * @returns {String} obj.iv (base64) iv
+ * @returns {String} obj.tag (base64) tag
+ */
+const encryptSymmetric = ({
+	plaintext,
+	key
+}: IEncryptSymmetricInput): IEncryptSymmetricOutput => {
+    validateEncryptionKey(key);
+    
+    const iv = crypto.randomBytes(BLOCK_SIZE_BYTES_32);
+    const secretKey = crypto.createSecretKey(key, 'base64');
+    const cipher = crypto.createCipheriv(ALGORITHM_AES_256_GCM, secretKey, iv);
+
+    let ciphertext = cipher.update(plaintext, 'utf8', 'base64');
+    ciphertext += cipher.final('base64');
+
+	return {
+		ciphertext,
+		iv: iv.toString('base64'),
+		tag: cipher.getAuthTag().toString('base64')
+	};
+};
+
+/**
+ * Return symmetrically decrypted [ciphertext] using [iv], [tag],
+ * and [key].
+ * @param {Object} obj
+ * @param {String} obj.ciphertext - ciphertext to decrypt
+ * @param {String} obj.iv - (base64) 256-bit iv
+ * @param {String} obj.tag - (base64) tag
+ * @param {String} obj.key - (base64) 256-bit key
+ * @returns {String} cleartext - the deciphered ciphertext
+ */
+const decryptSymmetric = ({
+	ciphertext,
+	iv,
+	tag,
+	key
+}: IDecryptSymmetricInput): string => {
+    validateEncryptionKey(key);
+
+    const secretKey = crypto.createSecretKey(key, 'base64');
+
+    const decipher = crypto.createDecipheriv(
+        ALGORITHM_AES_256_GCM,
+        secretKey,
+        Buffer.from(iv, 'base64')
+    );
+
+    decipher.setAuthTag(Buffer.from(tag, 'base64'));
+
+    let cleartext = decipher.update(ciphertext, 'base64', 'utf8');
+    cleartext += decipher.final('utf8');
+
+    return cleartext;
+};
+
+/**
+ * Return symmetrically encrypted [plaintext] using [key].
+ * 
+ * NOTE: THIS FUNCTION SHOULD NOT BE USED FOR ALL FUTURE
+ * ENCRYPTION OPERATIONS UNLESS IT TOUCHES OLD FUNCTIONALITY
+ * THAT USES IT. USE encryptSymmetric() instead
+ * 
+ * @param {Object} obj
+ * @param {String} obj.plaintext - (utf8) plaintext to encrypt
+ * @param {String} obj.key - (base64) 256-bit key
+ * @returns {Object} obj
+ * @returns {String} obj.ciphertext (base64) ciphertext
+ * @returns {String} obj.iv (base64) iv
+ * @returns {String} obj.tag (base64) tag
+ */
+const encryptSymmetric128BitHexKeyUTF8 = ({
+    plaintext,
+    key
+}: IEncryptSymmetricInput) => {
+    const iv = crypto.randomBytes(BLOCK_SIZE_BYTES_16);
+    const cipher = crypto.createCipheriv(ALGORITHM_AES_256_GCM, key, iv);
+
+    let ciphertext = cipher.update(plaintext, 'utf8', 'base64');
+    ciphertext += cipher.final('base64');
+
+    return {
+        ciphertext,
+        iv: iv.toString('base64'),
+        tag: cipher.getAuthTag().toString('base64')
+    };
+}
+/**
+ * Return symmetrically decrypted [ciphertext] using [iv], [tag],
+ * and [key].
+ * 
+ * NOTE: THIS FUNCTION SHOULD NOT BE USED FOR ALL FUTURE
+ * DECRYPTION OPERATIONS UNLESS IT TOUCHES OLD FUNCTIONALITY
+ * THAT USES IT. USE decryptSymmetric() instead
+ * 
+ * @param {Object} obj
+ * @param {String} obj.ciphertext - ciphertext to decrypt
+ * @param {String} obj.iv - (base64) 256-bit iv
+ * @param {String} obj.tag - (base64) tag
+ * @param {String} obj.key - (hex) 128-bit key
+ * @returns {String} cleartext - the deciphered ciphertext
+ */
+const decryptSymmetric128BitHexKeyUTF8 = ({
+    ciphertext,
+    iv,
+    tag,
+    key
+}: IDecryptSymmetricInput) => {
+    const decipher = crypto.createDecipheriv(
+        ALGORITHM_AES_256_GCM,
+        key,
+        Buffer.from(iv, 'base64')
+    );
+
+    decipher.setAuthTag(Buffer.from(tag, 'base64'));
+
+    let cleartext = decipher.update(ciphertext, 'base64', 'utf8');
+    cleartext += decipher.final('utf8');
+    
+    return cleartext;
+}
+
+export {
+	generateKeyPair,
+	encryptAsymmetric,
+	decryptAsymmetric,
+	encryptSymmetric,
+	decryptSymmetric,
+    encryptSymmetric128BitHexKeyUTF8,
+    decryptSymmetric128BitHexKeyUTF8
+};