crypto: fix Node_SignFinal

PR #11705 switched Node away from using using OpenSSL's legacy EVP_Sign*
and EVP_Verify* APIs. Instead, it computes a hash normally via
EVP_Digest* and then uses EVP_PKEY_sign and EVP_PKEY_verify to verify
the hash directly. This change corrects two problems:

1. The documentation still recommends the signature algorithm EVP_MD
   names of OpenSSL's legacy APIs. OpenSSL has since moved away from
   thosee, which is why ECDSA was strangely inconsistent. (This is why
   "ecdsa-with-SHA256" was missing.)

2. Node_SignFinal copied some code from EVP_SignFinal's internals. This
   is problematic for OpenSSL 1.1.0 and is missing a critical check
   that prevents pkey->pkey.ptr from being cast to the wrong type.

To resolve this, remove the non-EVP_PKEY_sign codepath. This codepath is
no longer necessary. PR #11705's verify half was already assuming all
EVP_PKEYs supported EVP_PKEY_sign and EVP_PKEY_verify. Also, in the
documentation, point users towards using hash function names which are
more consisent. This avoids an ECDSA special-case and some strangeness
around RSA-PSS ("RSA-SHA256" is the OpenSSL name of the
sha256WithRSAEncryption OID which is not used for RSA-PSS).

PR-URL: https://github.com/nodejs/node/pull/15024
Reviewed-By: Shigeki Ohtsu <ohtsu@ohtsu.org>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

1 files changed, 2 insertions, 2 deletions

diff --git a/test/fixtures/0-dns/create-cert.js b/test/fixtures/0-dns/create-cert.js
index 7a353906e4..9a72104887 100644
--- a/test/fixtures/0-dns/create-cert.js
+++ b/test/fixtures/0-dns/create-cert.js
@@ -8,7 +8,7 @@ const BN = asn1.bignum;
 const id_at_commonName = [ 2, 5, 4, 3 ];
 const rsaEncryption = [1, 2, 840, 113549, 1, 1, 1];
 const sha256WithRSAEncryption = [1, 2, 840, 113549, 1, 1, 11];
-const sigalg = 'RSA-SHA256';
+const digest = 'SHA256';
 
 const private_key = fs.readFileSync('./0-dns-key.pem');
 // public key file can be generated from the private key with
@@ -59,7 +59,7 @@ const tbs = {
 
 const tbs_der = rfc5280.TBSCertificate.encode(tbs, 'der');
 
-const sign = crypto.createSign(sigalg);
+const sign = crypto.createSign(digest);
 sign.update(tbs_der);
 const signature = sign.sign(private_key);