kris/boringssl
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Better document RSAZ and tidy up types.

Browse Source 
It's an assembly function, so types are a little meaningless, but
everything is passed through as BN_ULONG, so be consistent. Also
annotate all the RSAZ prototypes with sizes.

Change-Id: I32e59e896da39e79c30ce9db52652fd645a033b4
Reviewed-on: https://boringssl-review.googlesource.com/c/34625
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
This commit is contained in:
David Benjamin 2018-12-31 19:36:22 +00:00 committed by CQ bot account: commit-bot@chromium.org
parent e569c7e25d
commit 3859fc883d
1 changed files with 41 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
crypto/fipsmodule/bn/rsaz_exp.c
View File

@ -24,15 +24,41 @@
#include "../../internal.h"
// RSAZ represents 1024-bit integers using unsaturated 29-bit limbs stored in
// 64-bit integers. This requires 36 limbs but padded up to 40.
//
// See crypto/bn/asm/rsaz-avx2.pl for further details.
void rsaz_1024_norm2red_avx2(void *red, const void *norm);
void rsaz_1024_mul_avx2(void *ret, const void *a, const void *b, const void *n,
BN_ULONG k);
void rsaz_1024_sqr_avx2(void *ret, const void *a, const void *n, BN_ULONG k,
int cnt);
void rsaz_1024_scatter5_avx2(void *tbl, const void *val, int i);
void rsaz_1024_gather5_avx2(void *val, const void *tbl, int i);
void rsaz_1024_red2norm_avx2(void *norm, const void *red);
// rsaz_1024_norm2red_avx2 converts |norm| from |BIGNUM| to RSAZ representation
// and writes the result to |red|.
void rsaz_1024_norm2red_avx2(BN_ULONG red[40], const BN_ULONG norm[16]);
// rsaz_1024_mul_avx2 computes |a| * |b| mod |n| and writes the result to |ret|.
// Inputs and outputs are in Montgomery form, using RSAZ's representation. |k|
// is -|n|^-1 mod 2^64 or |n0| from |BN_MONT_CTX|.
void rsaz_1024_mul_avx2(BN_ULONG ret[40], const BN_ULONG a[40],
const BN_ULONG b[40], const BN_ULONG n[40], BN_ULONG k);
// rsaz_1024_mul_avx2 computes |a|^(2*|count|) mod |n| and writes the result to
// |ret|. Inputs and outputs are in Montgomery form, using RSAZ's
// representation. |k| is -|n|^-1 mod 2^64 or |n0| from |BN_MONT_CTX|.
void rsaz_1024_sqr_avx2(BN_ULONG ret[40], const BN_ULONG a[40],
const BN_ULONG n[40], BN_ULONG k, int count);
// rsaz_1024_scatter5_avx2 stores |val| at index |i| of |tbl|. |i| must be
// positive and at most 31. Note the table only uses 18 |BN_ULONG|s per entry
// instead of 40. It packs two 29-bit limbs into each |BN_ULONG| and only stores
// 36 limbs rather than the padded 40.
void rsaz_1024_scatter5_avx2(BN_ULONG tbl[32 * 18], const BN_ULONG val[40],
int i);
// rsaz_1024_gather5_avx2 loads index |i| of |tbl| and writes it to |val|.
void rsaz_1024_gather5_avx2(BN_ULONG val[40], const BN_ULONG tbl[32 * 18],
int i);
// rsaz_1024_red2norm_avx2 converts |red| from RSAZ to |BIGNUM| representation
// and writes the result to |norm|.
void rsaz_1024_red2norm_avx2(BN_ULONG norm[16], const BN_ULONG red[40]);
// one is 1 in RSAZ's representation.
alignas(64) static const BN_ULONG one[40] = {
@ -49,22 +75,21 @@ void RSAZ_1024_mod_exp_avx2(BN_ULONG result_norm[16],
const BN_ULONG exponent[16],
const BN_ULONG m_norm[16], const BN_ULONG RR[16],
BN_ULONG k0,
BN_ULONG storage_words[MOD_EXP_CTIME_STORAGE_LEN]) {
BN_ULONG storage[MOD_EXP_CTIME_STORAGE_LEN]) {
OPENSSL_STATIC_ASSERT(MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH % 64 == 0,
"MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH is too small");
unsigned char *storage = (unsigned char *)storage_words;
assert((uintptr_t)storage % 64 == 0);
unsigned char *a_inv, *m, *result, *table_s = storage + (320 * 3),
*R2 = table_s; // borrow
BN_ULONG *a_inv, *m, *result, *table_s = storage + 40 * 3, *R2 = table_s;
// Note |R2| aliases |table_s|.
if (((((uintptr_t)storage & 4095) + 320) >> 12) != 0) {
result = storage;
a_inv = storage + 320;
m = storage + (320 * 2); // should not cross page
a_inv = storage + 40;
m = storage + 40 * 2; // should not cross page
} else {
m = storage; // should not cross page
result = storage + 320;
a_inv = storage + (320 * 2);
result = storage + 40;
a_inv = storage + 40 * 2;
}
rsaz_1024_norm2red_avx2(m, m_norm);