deps: float 0c27d793 from openssl (ECDSA blinding)

Pending OpenSSL 1.1.0i release.

Refs: https://www.nccgroup.trust/us/our-research/technical-advisory-return-of-the-hidden-number-problem/
PR-URL: https://github.com/nodejs/node/pull/21345


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Shigeki Ohtsu <ohtsu@ohtsu.org>
Reviewed-By: James M Snell <jasnell@gmail.com>
Upstream: https://github.com/openssl/openssl/commit/0c27d793



Original commit message:
    Add blinding to an ECDSA signature

    Keegan Ryan (NCC Group) has demonstrated a side channel attack on an
    ECDSA signature operation. During signing the signer calculates:

    s:= k^-1 * (m + r * priv_key) mod order

    The addition operation above provides a sufficient signal for a
    flush+reload attack to derive the private key given sufficient signature
    operations.

    As a mitigation (based on a suggestion from Keegan) we add blinding to
    the operation so that:

    s := k^-1 * blind^-1 (blind * m + blind * r * priv_key) mod order

    Since this attack is a localhost side channel only no CVE is assigned.

Reviewed-by: Rich Salz <rsalz@openssl.org>