diff options
| author | Andrey Matyukov <andrey.matyukov@intel.com> | 2020-12-08 22:53:39 +0300 |
|---|---|---|
| committer | Matt Caswell <matt@openssl.org> | 2021-03-22 09:48:00 +0000 |
| commit | c781eb1c63c243cb64dbe3066a43dc172aaab3b8 (patch) | |
| tree | 36adf4600064afddfb87e16bee0736c6427ca523 /crypto/rsa | |
| parent | db89d8f04bb131bbf0e2b87eb9a1515076c893d3 (diff) | |
Dual 1024-bit exponentiation optimization for Intel IceLake CPU
with AVX512_IFMA + AVX512_VL instructions, primarily for RSA CRT private key
operations. It uses 256-bit registers to avoid CPU frequency scaling issues.
The performance speedup for RSA2k signature on ICL is ~2x.
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/13750)
Diffstat (limited to 'crypto/rsa')
| -rw-r--r-- | crypto/rsa/rsa_ossl.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/crypto/rsa/rsa_ossl.c b/crypto/rsa/rsa_ossl.c index 9f98c037c8..1817392e76 100644 --- a/crypto/rsa/rsa_ossl.c +++ b/crypto/rsa/rsa_ossl.c @@ -688,15 +688,20 @@ static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) if (/* m1 = I moq q */ !bn_from_mont_fixed_top(m1, I, rsa->_method_mod_q, ctx) || !bn_to_mont_fixed_top(m1, m1, rsa->_method_mod_q, ctx) - /* m1 = m1^dmq1 mod q */ - || !BN_mod_exp_mont_consttime(m1, m1, rsa->dmq1, rsa->q, ctx, - rsa->_method_mod_q) /* r1 = I mod p */ || !bn_from_mont_fixed_top(r1, I, rsa->_method_mod_p, ctx) || !bn_to_mont_fixed_top(r1, r1, rsa->_method_mod_p, ctx) - /* r1 = r1^dmp1 mod p */ - || !BN_mod_exp_mont_consttime(r1, r1, rsa->dmp1, rsa->p, ctx, - rsa->_method_mod_p) + /* + * Use parallel exponentiations optimization if possible, + * otherwise fallback to two sequential exponentiations: + * m1 = m1^dmq1 mod q + * r1 = r1^dmp1 mod p + */ + || !BN_mod_exp_mont_consttime_x2(m1, m1, rsa->dmq1, rsa->q, + rsa->_method_mod_q, + r1, r1, rsa->dmp1, rsa->p, + rsa->_method_mod_p, + ctx) /* r1 = (r1 - m1) mod p */ /* * bn_mod_sub_fixed_top is not regular modular subtraction, |