crypto: add keyObject.export() 'jwk' format option

Adds [JWK](https://tools.ietf.org/html/rfc7517) keyObject.export format
option.

Supported key types: `ec`, `rsa`, `ed25519`, `ed448`, `x25519`, `x448`,
and symmetric keys, resulting in JWK `kty` (Key Type) values `EC`,
`RSA`, `OKP`, and `oct`.

`rsa-pss` is not supported since the JWK format does not support
PSS Parameters.

`EC` JWK curves supported are `P-256`, `secp256k1`, `P-384`, and `P-521`

PR-URL: #37081
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>

doc/api/crypto.md

@@ -1348,35 +1348,41 @@ keys.
 ### `keyObject.export([options])`
 <!-- YAML
 added: v11.6.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/37081
+    description: Added support for `'jwk'` format.
 -->
 
 * `options`: {Object}
-* Returns: {string | Buffer}
+* Returns: {string | Buffer | Object}
 
-For symmetric keys, this function allocates a `Buffer` containing the key
-material and ignores any options.
+For symmetric keys, the following encoding options can be used:
 
-For asymmetric keys, the `options` parameter is used to determine the export
-format.
+* `format`: {string} Must be `'buffer'` (default) or `'jwk'`.
 
 For public keys, the following encoding options can be used:
 
 * `type`: {string} Must be one of `'pkcs1'` (RSA only) or `'spki'`.
-* `format`: {string} Must be `'pem'` or `'der'`.
+* `format`: {string} Must be `'pem'`, `'der'`, or `'jwk'`.
 
 For private keys, the following encoding options can be used:
 
 * `type`: {string} Must be one of `'pkcs1'` (RSA only), `'pkcs8'` or
   `'sec1'` (EC only).
-* `format`: {string} Must be `'pem'` or `'der'`.
+* `format`: {string} Must be `'pem'`, `'der'`, or `'jwk'`.
 * `cipher`: {string} If specified, the private key will be encrypted with
    the given `cipher` and `passphrase` using PKCS#5 v2.0 password based
    encryption.
 * `passphrase`: {string | Buffer} The passphrase to use for encryption, see
   `cipher`.
 
-When PEM encoding was selected, the result will be a string, otherwise it will
-be a buffer containing the data encoded as DER.
+The result type depends on the selected encoding format, when PEM the
+result is a string, when DER it will be a buffer containing the data
+encoded as DER, when [JWK][] it will be an object.
+
+When [JWK][] encoding format was selected, all other encoding options are
+ignored.
 
 PKCS#1, SEC1, and PKCS#8 type keys can be encrypted by using a combination of
 the `cipher` and `format` options. The PKCS#8 `type` can be used with any
@@ -4355,6 +4361,7 @@ See the [list of SSL OP Flags][] for details.
 [Crypto constants]: #crypto_crypto_constants_1
 [HTML 5.2]: https://www.w3.org/TR/html52/changes.html#features-removed
 [HTML5's `keygen` element]: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/keygen
+[JWK]: https://tools.ietf.org/html/rfc7517
 [NIST SP 800-131A]: https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-131Ar1.pdf
 [NIST SP 800-132]: https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-132.pdf
 [NIST SP 800-38D]: https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf

doc/api/errors.md

@@ -919,6 +919,18 @@ added: v15.0.0
 
 Initialization of an asynchronous crypto operation failed.
 
+<a id="ERR_CRYPTO_JWK_UNSUPPORTED_CURVE"></a>
+### `ERR_CRYPTO_JWK_UNSUPPORTED_CURVE`
+
+Key's Elliptic Curve is not registered for use in the
+[JSON Web Key Elliptic Curve Registry][].
+
+<a id="ERR_CRYPTO_JWK_UNSUPPORTED_KEY_TYPE"></a>
+### `ERR_CRYPTO_JWK_UNSUPPORTED_KEY_TYPE`
+
+Key's Asymmetric Key Type is not registered for use in the
+[JSON Web Key Types Registry][].
+
 <a id="ERR_CRYPTO_OPERATION_FAILED"></a>
 ### `ERR_CRYPTO_OPERATION_FAILED`
 <!-- YAML
@@ -2716,6 +2728,8 @@ The native call from `process.cpuUsage` could not be processed.
 
 [ES Module]: esm.md
 [ICU]: intl.md#intl_internationalization_support
+[JSON Web Key Elliptic Curve Registry]: https://www.iana.org/assignments/jose/jose.xhtml#web-key-elliptic-curve
+[JSON Web Key Types Registry]: https://www.iana.org/assignments/jose/jose.xhtml#web-key-types
 [Node.js error codes]: #nodejs-error-codes
 [RFC 7230 Section 3]: https://tools.ietf.org/html/rfc7230#section-3
 [Subresource Integrity specification]: https://www.w3.org/TR/SRI/#the-integrity-attribute

lib/internal/crypto/keys.js

@@ -22,6 +22,11 @@ const {
   kKeyEncodingSEC1,
 } = internalBinding('crypto');
 
+const {
+  validateObject,
+  validateOneOf,
+} = require('internal/validators');
+
 const {
   codes: {
     ERR_CRYPTO_INCOMPATIBLE_KEY_OPTIONS,
@@ -30,6 +35,8 @@ const {
     ERR_INVALID_ARG_VALUE,
     ERR_OUT_OF_RANGE,
     ERR_OPERATION_FAILED,
+    ERR_CRYPTO_JWK_UNSUPPORTED_CURVE,
+    ERR_CRYPTO_JWK_UNSUPPORTED_KEY_TYPE,
   }
 } = require('internal/errors');
 
@@ -124,13 +131,22 @@ const [
       return this[kHandle].getSymmetricKeySize();
     }
 
-    export() {
+    export(options) {
+      if (options !== undefined) {
+        validateObject(options, 'options');
+        validateOneOf(
+          options.format, 'options.format', [undefined, 'buffer', 'jwk']);
+        if (options.format === 'jwk') {
+          return this[kHandle].exportJwk({});
+        }
+      }
       return this[kHandle].export();
     }
   }
 
   const kAsymmetricKeyType = Symbol('kAsymmetricKeyType');
   const kAsymmetricKeyDetails = Symbol('kAsymmetricKeyDetails');
+  const kAsymmetricKeyJWKProperties = Symbol('kAsymmetricKeyJWKProperties');
 
   function normalizeKeyDetails(details = {}) {
     if (details.publicExponent !== undefined) {
@@ -163,18 +179,44 @@ const [
           return {};
       }
     }
+
+    [kAsymmetricKeyJWKProperties]() {
+      switch (this.asymmetricKeyType) {
+        case 'rsa': return {};
+        case 'ec':
+          switch (this.asymmetricKeyDetails.namedCurve) {
+            case 'prime256v1': return { crv: 'P-256' };
+            case 'secp256k1': return { crv: 'secp256k1' };
+            case 'secp384r1': return { crv: 'P-384' };
+            case 'secp521r1': return { crv: 'P-521' };
+            default:
+              throw new ERR_CRYPTO_JWK_UNSUPPORTED_CURVE(
+                this.asymmetricKeyDetails.namedCurve);
+          }
+        case 'ed25519': return { crv: 'Ed25519' };
+        case 'ed448': return { crv: 'Ed448' };
+        case 'x25519': return { crv: 'X25519' };
+        case 'x448': return { crv: 'X448' };
+        default:
+          throw new ERR_CRYPTO_JWK_UNSUPPORTED_KEY_TYPE();
+      }
+    }
   }
 
   class PublicKeyObject extends AsymmetricKeyObject {
     constructor(handle) {
       super('public', handle);
     }
 
-    export(encoding) {
+    export(options) {
+      if (options && options.format === 'jwk') {
+        const properties = this[kAsymmetricKeyJWKProperties]();
+        return this[kHandle].exportJwk(properties);
+      }
       const {
         format,
         type
-      } = parsePublicKeyEncoding(encoding, this.asymmetricKeyType);
+      } = parsePublicKeyEncoding(options, this.asymmetricKeyType);
       return this[kHandle].export(format, type);
     }
   }
@@ -184,13 +226,21 @@ const [
       super('private', handle);
     }
 
-    export(encoding) {
+    export(options) {
+      if (options && options.format === 'jwk') {
+        if (options.passphrase !== undefined) {
+          throw new ERR_CRYPTO_INCOMPATIBLE_KEY_OPTIONS(
+            'jwk', 'does not support encryption');
+        }
+        const properties = this[kAsymmetricKeyJWKProperties]();
+        return this[kHandle].exportJwk(properties);
+      }
       const {
         format,
         type,
         cipher,
         passphrase
-      } = parsePrivateKeyEncoding(encoding, this.asymmetricKeyType);
+      } = parsePrivateKeyEncoding(options, this.asymmetricKeyType);
       return this[kHandle].export(format, type, cipher, passphrase);
     }
   }

lib/internal/errors.js

@@ -839,6 +839,8 @@ E('ERR_CRYPTO_INVALID_DIGEST', 'Invalid digest: %s', TypeError);
 E('ERR_CRYPTO_INVALID_KEY_OBJECT_TYPE',
   'Invalid key object type %s, expected %s.', TypeError);
 E('ERR_CRYPTO_INVALID_STATE', 'Invalid state for operation %s', Error);
+E('ERR_CRYPTO_JWK_UNSUPPORTED_CURVE', 'Unsupported JWK EC curve: %s.', Error);
+E('ERR_CRYPTO_JWK_UNSUPPORTED_KEY_TYPE', 'Unsupported JWK Key Type.', Error);
 E('ERR_CRYPTO_PBKDF2_ERROR', 'PBKDF2 error', Error);
 E('ERR_CRYPTO_SCRYPT_INVALID_PARAMETER', 'Invalid scrypt parameter', Error);
 E('ERR_CRYPTO_SCRYPT_NOT_SUPPORTED', 'Scrypt algorithm not supported', Error);

test/fixtures/keys/Makefile

@@ -75,6 +75,14 @@ all: \
   ed448_public.pem \
   x448_private.pem \
   x448_public.pem \
+  ec_p256_private.pem \
+  ec_p256_public.pem \
+  ec_p384_private.pem \
+  ec_p384_public.pem \
+  ec_p521_private.pem \
+  ec_p521_public.pem \
+  ec_secp256k1_private.pem \
+  ec_secp256k1_public.pem \
 
 #
 # Create Certificate Authority: ca1
@@ -663,7 +671,7 @@ rsa_cert_foafssl_b.modulus: rsa_cert_foafssl_b.crt
 
 # Have to parse out the hex exponent
 rsa_cert_foafssl_b.exponent: rsa_cert_foafssl_b.crt
-	openssl x509 -in  rsa_cert_foafssl_b.crt -text | grep -o 'Exponent:.*' | sed 's/\(.*(\|).*\)//g' > rsa_cert_foafssl_b.exponent 
+	openssl x509 -in  rsa_cert_foafssl_b.crt -text | grep -o 'Exponent:.*' | sed 's/\(.*(\|).*\)//g' > rsa_cert_foafssl_b.exponent
 
 # openssl outputs `SPKAC=[SPKAC]`. That prefix needs to be removed to work with node
 rsa_spkac.spkac: rsa_private.pem
@@ -733,6 +741,38 @@ x448_private.pem:
 x448_public.pem: x448_private.pem
 	openssl pkey -in x448_private.pem -pubout -out x448_public.pem
 
+ec_p256_private.pem:
+	openssl ecparam -name prime256v1 -genkey -noout -out sec1_ec_p256_private.pem
+	openssl pkcs8 -topk8 -nocrypt -in sec1_ec_p256_private.pem -out ec_p256_private.pem
+	rm sec1_ec_p256_private.pem
+
+ec_p256_public.pem: ec_p256_private.pem
+	openssl ec -in ec_p256_private.pem -pubout -out ec_p256_public.pem
+
+ec_p384_private.pem:
+	openssl ecparam -name secp384r1 -genkey -noout -out sec1_ec_p384_private.pem
+	openssl pkcs8 -topk8 -nocrypt -in sec1_ec_p384_private.pem -out ec_p384_private.pem
+	rm sec1_ec_p384_private.pem
+
+ec_p384_public.pem: ec_p384_private.pem
+	openssl ec -in ec_p384_private.pem -pubout -out ec_p384_public.pem
+
+ec_p521_private.pem:
+	openssl ecparam -name secp521r1 -genkey -noout -out sec1_ec_p521_private.pem
+	openssl pkcs8 -topk8 -nocrypt -in sec1_ec_p521_private.pem -out ec_p521_private.pem
+	rm sec1_ec_p521_private.pem
+
+ec_p521_public.pem: ec_p521_private.pem
+	openssl ec -in ec_p521_private.pem -pubout -out ec_p521_public.pem
+
+ec_secp256k1_private.pem:
+	openssl ecparam -name secp256k1 -genkey -noout -out sec1_ec_secp256k1_private.pem
+	openssl pkcs8 -topk8 -nocrypt -in sec1_ec_secp256k1_private.pem -out ec_secp256k1_private.pem
+	rm sec1_ec_secp256k1_private.pem
+
+ec_secp256k1_public.pem: ec_secp256k1_private.pem
+	openssl ec -in ec_secp256k1_private.pem -pubout -out ec_secp256k1_public.pem
+
 clean:
 	rm -f *.pfx *.pem *.srl ca2-database.txt ca2-serial fake-startcom-root-serial *.print *.old fake-startcom-root-issued-certs/*.pem
 	@> fake-startcom-root-database.txt

test/fixtures/keys/ec_p256_private.pem

@@ -0,0 +1,5 @@
+-----BEGIN PRIVATE KEY-----
+MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgDxBsPQPIgMuMyQbx
+zbb9toew6Ev6e9O6ZhpxLNgmAEqhRANCAARfSYxhH+6V5lIg+M3O0iQBLf+53kuE
+2luIgWnp81/Ya1Gybj8tl4tJVu1GEwcTyt8hoA7vRACmCHnI5B1+bNpS
+-----END PRIVATE KEY-----

test/fixtures/keys/ec_p256_public.pem

@@ -0,0 +1,4 @@
+-----BEGIN PUBLIC KEY-----
+MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEX0mMYR/uleZSIPjNztIkAS3/ud5L
+hNpbiIFp6fNf2GtRsm4/LZeLSVbtRhMHE8rfIaAO70QApgh5yOQdfmzaUg==
+-----END PUBLIC KEY-----

test/fixtures/keys/ec_p384_private.pem

@@ -0,0 +1,6 @@
+-----BEGIN PRIVATE KEY-----
+MIG2AgEAMBAGByqGSM49AgEGBSuBBAAiBIGeMIGbAgEBBDB3B+4e4C1OUxGftkEI
+Gb/SCulzUP/iE940CB6+B6WWO4LT76T8sMWiwOAGUsuZmyKhZANiAASE43efMYmC
+/7Tx90elDGBEkVnOUr4ZkMZrl/cqe8zfVy++MmayPhR46Ah3LesMCNV+J0eG15w0
+IYJ8uqasuMN6drU1LNbNYfW7+hR0woajldJpvHMPv7wlnGOlzyxH1yU=
+-----END PRIVATE KEY-----

test/fixtures/keys/ec_p384_public.pem

@@ -0,0 +1,5 @@
+-----BEGIN PUBLIC KEY-----
+MHYwEAYHKoZIzj0CAQYFK4EEACIDYgAEhON3nzGJgv+08fdHpQxgRJFZzlK+GZDG
+a5f3KnvM31cvvjJmsj4UeOgIdy3rDAjVfidHhtecNCGCfLqmrLjDena1NSzWzWH1
+u/oUdMKGo5XSabxzD7+8JZxjpc8sR9cl
+-----END PUBLIC KEY-----

test/fixtures/keys/ec_p521_private.pem

@@ -0,0 +1,8 @@
+-----BEGIN PRIVATE KEY-----
+MIHuAgEAMBAGByqGSM49AgEGBSuBBAAjBIHWMIHTAgEBBEIAEghuafcab9jXW4gO
+QLeDaKOlHEiskQFjiL8klijk6i6DNOXcFfaJ9GW48kxpodw16ttAf9Z1WQstfzpK
+GUetHImhgYkDgYYABAGixYI8Gbc5zNze6rH2/OmsFV3unOnY1GDqG9RTfpJZXpL9
+ChF1dG8HA4zxkM+X+jMSwm4THh0Wr1Euj9dK7E7QZwHd35XsQXgH13Hjc0QR9dvJ
+BWzlg+luNTY8CkaqiBdur5oFv/AjpXRimYxZDkhAEsTwXLwNohSUVMkN8IQtNI9D
+aQ==
+-----END PRIVATE KEY-----

test/fixtures/keys/ec_p521_public.pem

@@ -0,0 +1,6 @@
+-----BEGIN PUBLIC KEY-----
+MIGbMBAGByqGSM49AgEGBSuBBAAjA4GGAAQBosWCPBm3Oczc3uqx9vzprBVd7pzp
+2NRg6hvUU36SWV6S/QoRdXRvBwOM8ZDPl/ozEsJuEx4dFq9RLo/XSuxO0GcB3d+V
+7EF4B9dx43NEEfXbyQVs5YPpbjU2PApGqogXbq+aBb/wI6V0YpmMWQ5IQBLE8Fy8
+DaIUlFTJDfCELTSPQ2k=
+-----END PUBLIC KEY-----

test/fixtures/keys/ec_secp256k1_private.pem

@@ -0,0 +1,5 @@
+-----BEGIN PRIVATE KEY-----
+MIGEAgEAMBAGByqGSM49AgEGBSuBBAAKBG0wawIBAQQgc34ocwTwpFa9NZZh3l88
+qXyrkoYSxvC0FEsU5v1v4IOhRANCAARw7OEVKlbGFqUJtY10/Yf/JSR0LzUL1PZ1
+4Ol/ErujAPgNwwGU5PSD6aTfn9NycnYB2hby9XwB2qF3+El+DV8q
+-----END PRIVATE KEY-----

test/fixtures/keys/ec_secp256k1_public.pem

@@ -0,0 +1,4 @@
+-----BEGIN PUBLIC KEY-----
+MFYwEAYHKoZIzj0CAQYFK4EEAAoDQgAEcOzhFSpWxhalCbWNdP2H/yUkdC81C9T2
+deDpfxK7owD4DcMBlOT0g+mk35/TcnJ2AdoW8vV8Adqhd/hJfg1fKg==
+-----END PUBLIC KEY-----