Commit Graph

4 Commits

Author SHA1 Message Date
David Benjamin
c2e8d016f5 Fix beeu_mod_inverse_vartime CFI annotations and preamble.
This was also caught by the in-progress unwind tester. There are two
issues here.  First, .cfi_endproc must come after ret to fully cover the
function.  More importantly, this function is confused about whether it
has a frame pointer or not.

It looks like it does (movq %rsp, %rbp), and annotates accordingly, but
it does not actually use the frame pointer. It cannot. $y4 is rbp and
gets clobbered immediately after the preamble!

Remove this instruction and align the CFI annotations with a
frame-pointer-less function.

Bug: 181
Change-Id: I47b5f9798b3bcee1748e537b21c173d312a14b42
Reviewed-on: https://boringssl-review.googlesource.com/c/33947
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
2019-01-02 23:47:34 +00:00
Adam Langley
9edbc7ff9f Revert "Revert "Speed up ECDSA verify on x86-64.""
This reverts commit e907ed4c4b. CPUID
checks have been added so hopefully this time sticks.

Change-Id: I5e0e5b87427c1230132681f936b3c70bac8263b8
Reviewed-on: https://boringssl-review.googlesource.com/c/32924
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2018-11-07 23:57:22 +00:00
Adam Langley
e907ed4c4b Revert "Speed up ECDSA verify on x86-64."
This reverts commit 3d450d2844. It fails
SDE, looks like a missing CPUID check before using vector instructions.

Change-Id: I6b7dd71d9e5b1f509d2e018bd8be38c973476b4e
Reviewed-on: https://boringssl-review.googlesource.com/c/32864
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
2018-11-06 00:29:15 +00:00
Nir Drucker
3d450d2844 Speed up ECDSA verify on x86-64.
This commit improves the performance of ECDSA signature verification
(over NIST P-256 curve) for x86 platforms. The speedup is by a factor of 1.15x.
It does so by:
  1) Leveraging the fact that the verification does not need
     to run in constant time. To this end, we implemented:
    a) the function ecp_nistz256_points_mul_public in a similar way to
       the current ecp_nistz256_points_mul function by removing its constant
       time features.
    b) the Binary Extended Euclidean Algorithm (BEEU) in x86 assembly to
       replace the current modular inverse function used for the inversion.
  2) The last step in the ECDSA_verify function compares the (x) affine
     coordinate with the signature (r) value. Converting x from the Jacobian's
     representation to the affine coordinate requires to perform one inversions
     (x_affine = x * z^(-2)). We save this inversion and speed up the computations
     by instead bringing r to x (r_jacobian = r*z^2) which is faster.

The measured results are:
Before (on a Kaby Lake desktop with gcc-5):
Did 26000 ECDSA P-224 signing operations in 1002372us (25938.5 ops/sec)
Did 11000 ECDSA P-224 verify operations in 1043821us (10538.2 ops/sec)
Did 55000 ECDSA P-256 signing operations in 1017560us (54050.9 ops/sec)
Did 17000 ECDSA P-256 verify operations in 1051280us (16170.8 ops/sec)

After (on a Kaby Lake desktop with gcc-5):
Did 27000 ECDSA P-224 signing operations in 1011287us (26698.7 ops/sec)
Did 11640 ECDSA P-224 verify operations in 1076698us (10810.8 ops/sec)
Did 55000 ECDSA P-256 signing operations in 1016880us (54087.0 ops/sec)
Did 20000 ECDSA P-256 verify operations in 1038736us (19254.2 ops/sec)

Before (on a Skylake server platform with gcc-5):
Did 25000 ECDSA P-224 signing operations in 1021651us (24470.2 ops/sec)
Did 10373 ECDSA P-224 verify operations in 1046563us (9911.5 ops/sec)
Did 50000 ECDSA P-256 signing operations in 1002774us (49861.7 ops/sec)
Did 15000 ECDSA P-256 verify operations in 1006471us (14903.6 ops/sec)

After (on a Skylake server platform with gcc-5):
Did 25000 ECDSA P-224 signing operations in 1020958us (24486.8 ops/sec)
Did 10373 ECDSA P-224 verify operations in 1046359us (9913.4 ops/sec)
Did 50000 ECDSA P-256 signing operations in 1003996us (49801.0 ops/sec)
Did 18000 ECDSA P-256 verify operations in 1021604us (17619.4 ops/sec)

Developers and authors:
***************************************************************************
Nir Drucker (1,2), Shay Gueron (1,2)
(1) Amazon Web Services Inc.
(2) University of Haifa, Israel
***************************************************************************

Change-Id: Idd42a7bc40626bce974ea000b61fdb5bad33851c
Reviewed-on: https://boringssl-review.googlesource.com/c/31304
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
2018-11-05 23:48:07 +00:00