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| author | Marius Schilder <mschilder@google.com> | 2017-11-17 18:41:02 -0800 |
|---|---|---|
| committer | ChromeOS Commit Bot <chromeos-commit-bot@chromium.org> | 2017-12-16 01:13:24 +0000 |
| commit | f2c3504af3606ebd52f429049ed51d9c260f1951 (patch) | |
| tree | 49100bcfb171a6251af39f839d751d45aa820396 | |
| parent | c38a13e047c4f6280987aefe0dc341e60b1e70fc (diff) | |
| download | chrome-ec-f2c3504af3606ebd52f429049ed51d9c260f1951.tar.gz | |
g: speed up prime generation by ~40% (1024 bit).
We were using bn_modexp() to perform a simple modular square.
A bn_modexp_word() does this faster.
BRANCH=none
BUG=b:68167013
TEST=generate 128 primes from prng seed and verify they're same as before; tcg_test passes
Change-Id: I411a7d3fe2d68f93dc40bf74b941a637f9aa20ed
Reviewed-on: https://chromium-review.googlesource.com/778057
Commit-Ready: Marius Schilder <mschilder@chromium.org>
Tested-by: Marius Schilder <mschilder@chromium.org>
Reviewed-by: Marius Schilder <mschilder@chromium.org>
Reviewed-by: Nagendra Modadugu <ngm@google.com>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
(cherry picked from commit 1e855ebfcf74bb9a05d9f3cbefa4d6488dc41e1b)
Reviewed-on: https://chromium-review.googlesource.com/828690
Tested-by: Vadim Bendebury <vbendeb@chromium.org>
Commit-Queue: Vadim Bendebury <vbendeb@chromium.org>
| -rw-r--r-- | chip/g/dcrypto/bn.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/chip/g/dcrypto/bn.c b/chip/g/dcrypto/bn.c index 5c92f82fda..3131139f89 100644 --- a/chip/g/dcrypto/bn.c +++ b/chip/g/dcrypto/bn.c @@ -1070,13 +1070,11 @@ static int bn_probable_prime(const struct LITE_BIGNUM *p) int s = 0; uint32_t ONE_buf = 1; - uint32_t TWO_buf = 2; uint8_t r_buf[RSA_MAX_BYTES / 2]; uint8_t A_buf[RSA_MAX_BYTES / 2]; uint8_t y_buf[RSA_MAX_BYTES / 2]; struct LITE_BIGNUM ONE; - struct LITE_BIGNUM TWO; struct LITE_BIGNUM r; struct LITE_BIGNUM A; struct LITE_BIGNUM y; @@ -1105,7 +1103,6 @@ static int bn_probable_prime(const struct LITE_BIGNUM *p) DCRYPTO_bn_wrap(&A, A_buf, bn_size(p)); DCRYPTO_bn_wrap(&y, y_buf, bn_size(p)); - DCRYPTO_bn_wrap(&TWO, &TWO_buf, sizeof(TWO_buf)); for (j = 0; j < rounds; j++) { int i; @@ -1130,7 +1127,7 @@ static int bn_probable_prime(const struct LITE_BIGNUM *p) /* y = y ^ 2 mod p */ for (i = 0; i < s - 1; i++) { bn_copy(&A, &y); - bn_modexp(&y, &A, &TWO, p); + bn_modexp_word(&y, &A, 2, p); if (bn_eq(&y, &ONE)) return 0; |