crypto: add key object API

This commit makes multiple important changes:

1. A new key object API is introduced. The KeyObject class itself is
   not exposed to users, instead, several new APIs can be used to
   construct key objects: createSecretKey, createPrivateKey and
   createPublicKey. The new API also allows to convert between
   different key formats, and even though the API itself is not
   compatible to the WebCrypto standard in any way, it makes
   interoperability much simpler.

2. Key objects can be used instead of the raw key material in all
   relevant crypto APIs.

3. The handling of asymmetric keys has been unified and greatly
   improved. Node.js now fully supports both PEM-encoded and
   DER-encoded public and private keys.

4. Conversions between buffers and strings have been moved to native
   code for sensitive data such as symmetric keys due to security
   considerations such as zeroing temporary buffers.

5. For compatibility with older versions of the crypto API, this
   change allows to specify Buffers and strings as the "passphrase"
   option when reading or writing an encoded key. Note that this
   can result in unexpected behavior if the password contains a
   null byte.

PR-URL: #24234
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: tniessen

doc/api/crypto.md

@@ -763,6 +763,11 @@ The selected public or private key encoding is incompatible with other options.
 
 An invalid [crypto digest algorithm][] was specified.
 
+<a id="ERR_CRYPTO_INVALID_KEY_OBJECT_TYPE"></a>
+### ERR_CRYPTO_INVALID_KEY_OBJECT_TYPE
+
+The given crypto key object's type is invalid for the attempted operation.
+
 <a id="ERR_CRYPTO_INVALID_STATE"></a>
 ### ERR_CRYPTO_INVALID_STATE
 

doc/api/errors.md

@@ -59,6 +59,11 @@ const {
   generateKeyPair,
   generateKeyPairSync
 } = require('internal/crypto/keygen');
+const {
+  createSecretKey,
+  createPublicKey,
+  createPrivateKey
+} = require('internal/crypto/keys');
 const {
   DiffieHellman,
   DiffieHellmanGroup,
@@ -149,6 +154,9 @@ module.exports = exports = {
   createECDH,
   createHash,
   createHmac,
+  createPrivateKey,
+  createPublicKey,
+  createSecretKey,
   createSign,
   createVerify,
   getCiphers,

lib/crypto.js

@@ -12,6 +12,11 @@ const {
 } = require('internal/errors').codes;
 const { validateString } = require('internal/validators');
 
+const {
+  preparePrivateKey,
+  preparePublicOrPrivateKey,
+  prepareSecretKey
+} = require('internal/crypto/keys');
 const {
   getDefaultEncoding,
   kHandle,
@@ -38,19 +43,25 @@ const { deprecate, normalizeEncoding } = require('internal/util');
 // Lazy loaded for startup performance.
 let StringDecoder;
 
-function rsaFunctionFor(method, defaultPadding) {
+function rsaFunctionFor(method, defaultPadding, keyType) {
   return (options, buffer) => {
-    const key = options.key || options;
+    const { format, type, data, passphrase } =
+      keyType === 'private' ?
+        preparePrivateKey(options) :
+        preparePublicOrPrivateKey(options);
     const padding = options.padding || defaultPadding;
-    const passphrase = options.passphrase || null;
-    return method(toBuf(key), buffer, padding, passphrase);
+    return method(data, format, type, passphrase, buffer, padding);
   };
 }
 
-const publicEncrypt = rsaFunctionFor(_publicEncrypt, RSA_PKCS1_OAEP_PADDING);
-const publicDecrypt = rsaFunctionFor(_publicDecrypt, RSA_PKCS1_PADDING);
-const privateEncrypt = rsaFunctionFor(_privateEncrypt, RSA_PKCS1_PADDING);
-const privateDecrypt = rsaFunctionFor(_privateDecrypt, RSA_PKCS1_OAEP_PADDING);
+const publicEncrypt = rsaFunctionFor(_publicEncrypt, RSA_PKCS1_OAEP_PADDING,
+                                     'public');
+const publicDecrypt = rsaFunctionFor(_publicDecrypt, RSA_PKCS1_PADDING,
+                                     'private');
+const privateEncrypt = rsaFunctionFor(_privateEncrypt, RSA_PKCS1_PADDING,
+                                      'private');
+const privateDecrypt = rsaFunctionFor(_privateDecrypt, RSA_PKCS1_OAEP_PADDING,
+                                      'public');
 
 function getDecoder(decoder, encoding) {
   encoding = normalizeEncoding(encoding);
@@ -105,11 +116,7 @@ function createCipher(cipher, password, options, decipher) {
 
 function createCipherWithIV(cipher, key, options, decipher, iv) {
   validateString(cipher, 'cipher');
-  key = toBuf(key);
-  if (!isArrayBufferView(key)) {
-    throw invalidArrayBufferView('key', key);
-  }
-
+  key = prepareSecretKey(key);
   iv = toBuf(iv);
   if (iv !== null && !isArrayBufferView(iv)) {
     throw invalidArrayBufferView('iv', iv);

lib/internal/crypto/cipher.js

@@ -12,6 +12,10 @@ const {
   toBuf
 } = require('internal/crypto/util');
 
+const {
+  prepareSecretKey
+} = require('internal/crypto/keys');
+
 const { Buffer } = require('buffer');
 
 const {
@@ -88,10 +92,7 @@ function Hmac(hmac, key, options) {
   if (!(this instanceof Hmac))
     return new Hmac(hmac, key, options);
   validateString(hmac, 'hmac');
-  if (typeof key !== 'string' && !isArrayBufferView(key)) {
-    throw new ERR_INVALID_ARG_TYPE('key',
-                                   ['string', 'TypedArray', 'DataView'], key);
-  }
+  key = prepareSecretKey(key);
   this[kHandle] = new _Hmac();
   this[kHandle].init(hmac, toBuf(key));
   this[kState] = {

lib/internal/crypto/hash.js

@@ -6,24 +6,32 @@ const {
   generateKeyPairDSA,
   generateKeyPairEC,
   OPENSSL_EC_NAMED_CURVE,
-  OPENSSL_EC_EXPLICIT_CURVE,
-  PK_ENCODING_PKCS1,
-  PK_ENCODING_PKCS8,
-  PK_ENCODING_SPKI,
-  PK_ENCODING_SEC1,
-  PK_FORMAT_DER,
-  PK_FORMAT_PEM
+  OPENSSL_EC_EXPLICIT_CURVE
 } = internalBinding('crypto');
+const {
+  parsePublicKeyEncoding,
+  parsePrivateKeyEncoding,
+
+  PublicKeyObject,
+  PrivateKeyObject
+} = require('internal/crypto/keys');
 const { customPromisifyArgs } = require('internal/util');
 const { isUint32, validateString } = require('internal/validators');
 const {
-  ERR_CRYPTO_INCOMPATIBLE_KEY_OPTIONS,
   ERR_INVALID_ARG_TYPE,
   ERR_INVALID_ARG_VALUE,
   ERR_INVALID_CALLBACK,
   ERR_INVALID_OPT_VALUE
 } = require('internal/errors').codes;
 
+const { isArrayBufferView } = require('internal/util/types');
+
+function wrapKey(key, ctor) {
+  if (typeof key === 'string' || isArrayBufferView(key))
+    return key;
+  return new ctor(key);
+}
+
 function generateKeyPair(type, options, callback) {
   if (typeof options === 'function') {
     callback = options;
@@ -38,6 +46,9 @@ function generateKeyPair(type, options, callback) {
   const wrap = new AsyncWrap(Providers.KEYPAIRGENREQUEST);
   wrap.ondone = (ex, pubkey, privkey) => {
     if (ex) return callback.call(wrap, ex);
+    // If no encoding was chosen, return key objects instead.
+    pubkey = wrapKey(pubkey, PublicKeyObject);
+    privkey = wrapKey(privkey, PrivateKeyObject);
     callback.call(wrap, null, pubkey, privkey);
   };
 
@@ -69,86 +80,32 @@ function handleError(impl, wrap) {
 function parseKeyEncoding(keyType, options) {
   const { publicKeyEncoding, privateKeyEncoding } = options;
 
-  if (publicKeyEncoding == null || typeof publicKeyEncoding !== 'object')
-    throw new ERR_INVALID_OPT_VALUE('publicKeyEncoding', publicKeyEncoding);
-
-  const { format: strPublicFormat, type: strPublicType } = publicKeyEncoding;
-
-  let publicType;
-  if (strPublicType === 'pkcs1') {
-    if (keyType !== 'rsa') {
-      throw new ERR_CRYPTO_INCOMPATIBLE_KEY_OPTIONS(
-        strPublicType, 'can only be used for RSA keys');
-    }
-    publicType = PK_ENCODING_PKCS1;
-  } else if (strPublicType === 'spki') {
-    publicType = PK_ENCODING_SPKI;
+  let publicFormat, publicType;
+  if (publicKeyEncoding == null) {
+    publicFormat = publicType = undefined;
+  } else if (typeof publicKeyEncoding === 'object') {
+    ({
+      format: publicFormat,
+      type: publicType
+    } = parsePublicKeyEncoding(publicKeyEncoding, keyType,
+                               'publicKeyEncoding'));
   } else {
-    throw new ERR_INVALID_OPT_VALUE('publicKeyEncoding.type', strPublicType);
+    throw new ERR_INVALID_OPT_VALUE('publicKeyEncoding', publicKeyEncoding);
   }
 
-  let publicFormat;
-  if (strPublicFormat === 'der') {
-    publicFormat = PK_FORMAT_DER;
-  } else if (strPublicFormat === 'pem') {
-    publicFormat = PK_FORMAT_PEM;
+  let privateFormat, privateType, cipher, passphrase;
+  if (privateKeyEncoding == null) {
+    privateFormat = privateType = undefined;
+  } else if (typeof privateKeyEncoding === 'object') {
+    ({
+      format: privateFormat,
+      type: privateType,
+      cipher,
+      passphrase
+    } = parsePrivateKeyEncoding(privateKeyEncoding, keyType,
+                                'privateKeyEncoding'));
   } else {
-    throw new ERR_INVALID_OPT_VALUE('publicKeyEncoding.format',
-                                    strPublicFormat);
-  }
-
-  if (privateKeyEncoding == null || typeof privateKeyEncoding !== 'object')
     throw new ERR_INVALID_OPT_VALUE('privateKeyEncoding', privateKeyEncoding);
-
-  const {
-    cipher,
-    passphrase,
-    format: strPrivateFormat,
-    type: strPrivateType
-  } = privateKeyEncoding;
-
-  let privateType;
-  if (strPrivateType === 'pkcs1') {
-    if (keyType !== 'rsa') {
-      throw new ERR_CRYPTO_INCOMPATIBLE_KEY_OPTIONS(
-        strPrivateType, 'can only be used for RSA keys');
-    }
-    privateType = PK_ENCODING_PKCS1;
-  } else if (strPrivateType === 'pkcs8') {
-    privateType = PK_ENCODING_PKCS8;
-  } else if (strPrivateType === 'sec1') {
-    if (keyType !== 'ec') {
-      throw new ERR_CRYPTO_INCOMPATIBLE_KEY_OPTIONS(
-        strPrivateType, 'can only be used for EC keys');
-    }
-    privateType = PK_ENCODING_SEC1;
-  } else {
-    throw new ERR_INVALID_OPT_VALUE('privateKeyEncoding.type', strPrivateType);
-  }
-
-  let privateFormat;
-  if (strPrivateFormat === 'der') {
-    privateFormat = PK_FORMAT_DER;
-  } else if (strPrivateFormat === 'pem') {
-    privateFormat = PK_FORMAT_PEM;
-  } else {
-    throw new ERR_INVALID_OPT_VALUE('privateKeyEncoding.format',
-                                    strPrivateFormat);
-  }
-
-  if (cipher != null) {
-    if (typeof cipher !== 'string')
-      throw new ERR_INVALID_OPT_VALUE('privateKeyEncoding.cipher', cipher);
-    if (privateFormat === PK_FORMAT_DER &&
-        (privateType === PK_ENCODING_PKCS1 ||
-         privateType === PK_ENCODING_SEC1)) {
-      throw new ERR_CRYPTO_INCOMPATIBLE_KEY_OPTIONS(
-        strPrivateType, 'does not support encryption');
-    }
-    if (typeof passphrase !== 'string') {
-      throw new ERR_INVALID_OPT_VALUE('privateKeyEncoding.passphrase',
-                                      passphrase);
-    }
   }
 
   return {
@@ -181,8 +138,8 @@ function check(type, options, callback) {
         }
 
         impl = (wrap) => generateKeyPairRSA(modulusLength, publicExponent,
-                                            publicType, publicFormat,
-                                            privateType, privateFormat,
+                                            publicFormat, publicType,
+                                            privateFormat, privateType,
                                             cipher, passphrase, wrap);
       }
       break;
@@ -200,8 +157,8 @@ function check(type, options, callback) {
         }
 
         impl = (wrap) => generateKeyPairDSA(modulusLength, divisorLength,
-                                            publicType, publicFormat,
-                                            privateType, privateFormat,
+                                            publicFormat, publicType,
+                                            privateFormat, privateType,
                                             cipher, passphrase, wrap);
       }
       break;
@@ -219,8 +176,8 @@ function check(type, options, callback) {
           throw new ERR_INVALID_OPT_VALUE('paramEncoding', paramEncoding);
 
         impl = (wrap) => generateKeyPairEC(namedCurve, paramEncoding,
-                                           publicType, publicFormat,
-                                           privateType, privateFormat,
+                                           publicFormat, publicType,
+                                           privateFormat, privateType,
                                            cipher, passphrase, wrap);
       }
       break;