cosmopolitan/third_party/mbedtls/ecp384.c
Justine Tunney d1d4388201
Delete ASAN
It hasn't been helpful enough to be justify the maintenance burden. What
actually does help is mprotect(), kprintf(), --ftrace and --strace which
can always be counted upon to work correctly. We aren't losing much with
this change. Support for ASAN on AARCH64 was never implemented. Applying
ASAN to the core libc runtimes was disabled many months ago. If there is
some way to have an ASAN runtime for user programs that is less invasive
we can potentially consider reintroducing support. But now is premature.
2024-06-22 05:45:49 -07:00

597 lines
19 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:4;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/nexgen32e/x86feature.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "third_party/mbedtls/bignum_internal.h"
#include "third_party/mbedtls/ecp.h"
#include "third_party/mbedtls/ecp_internal.h"
#include "third_party/mbedtls/error.h"
#include "third_party/mbedtls/math.h"
#include "third_party/mbedtls/profile.h"
#include "third_party/mbedtls/select.h"
static bool
mbedtls_p384_isz( uint64_t p[6] )
{
return( !p[0] & !p[1] & !p[2] & !p[3] & !p[4] & !p[5] );
}
static bool
mbedtls_p384_gte( uint64_t p[7] )
{
return( (((int64_t)p[6] > 0) |
((!p[6]) &
((p[5] > 0xffffffffffffffff) |
((p[5] == 0xffffffffffffffff) &
((p[4] > 0xffffffffffffffff) |
((p[4] == 0xffffffffffffffff) &
((p[3] > 0xffffffffffffffff) |
((p[3] == 0xffffffffffffffff) &
((p[2] > 0xfffffffffffffffe) |
((p[2] == 0xfffffffffffffffe) &
((p[1] > 0xffffffff00000000) |
((p[1] == 0xffffffff00000000) &
((p[0] > 0x00000000ffffffff) |
(p[0] == 0x00000000ffffffff)))))))))))))) );
}
static int
mbedtls_p384_cmp( const uint64_t a[7],
const uint64_t b[7] )
{
int i, x, y, done = 0;
// return -1 if a[6] < b[6]
x = -((int64_t)a[6] < (int64_t)b[6]);
done = x;
// return +1 if a[6] > b[6]
y = (int64_t)a[6] > (int64_t)b[6];
x = Select(x, y, done);
done |= -y;
for (i = 6; i--;) {
y = -(a[i] < b[i]);
x = Select(x, y, done);
done |= y;
y = a[i] > b[i];
x = Select(x, y, done);
done |= -y;
}
return x;
}
static inline void
mbedtls_p384_red( uint64_t p[7] )
{
#if defined(__x86_64__) && !defined(__STRICT_ANSI__)
asm("subq\t%1,%0\n\t"
"sbbq\t%2,8+%0\n\t"
"sbbq\t%3,16+%0\n\t"
"sbbq\t%4,24+%0\n\t"
"sbbq\t%4,32+%0\n\t"
"sbbq\t%4,40+%0\n\t"
"sbbq\t$0,48+%0"
: "+o"(*p)
: "r"(0x00000000ffffffffl), "r"(0xffffffff00000000),
"i"(0xfffffffffffffffel), "i"(0xffffffffffffffff)
: "memory", "cc");
#else
uint64_t c;
SBB( p[0], p[0], 0x00000000ffffffff, 0, c );
SBB( p[1], p[1], 0xffffffff00000000, c, c );
SBB( p[2], p[2], 0xfffffffffffffffe, c, c );
SBB( p[3], p[3], 0xffffffffffffffff, c, c );
SBB( p[4], p[4], 0xffffffffffffffff, c, c );
SBB( p[5], p[5], 0xffffffffffffffff, c, c );
SBB( p[6], p[6], 0, c, c );
#endif
}
static inline void
mbedtls_p384_gro( uint64_t p[7] )
{
#if defined(__x86_64__) && !defined(__STRICT_ANSI__)
asm("addq\t%1,%0\n\t"
"adcq\t%2,8+%0\n\t"
"adcq\t%3,16+%0\n\t"
"adcq\t%4,24+%0\n\t"
"adcq\t%4,32+%0\n\t"
"adcq\t%4,40+%0\n\t"
"adcq\t$0,48+%0"
: "+o"(*p)
: "r"(0x00000000ffffffffl), "r"(0xffffffff00000000),
"i"(0xfffffffffffffffel), "i"(0xffffffffffffffff)
: "memory", "cc");
#else
uint64_t c;
ADC( p[0], p[0], 0x00000000ffffffff, 0, c );
ADC( p[1], p[1], 0xffffffff00000000, c, c );
ADC( p[2], p[2], 0xfffffffffffffffe, c, c );
ADC( p[3], p[3], 0xffffffffffffffff, c, c );
ADC( p[4], p[4], 0xffffffffffffffff, c, c );
ADC( p[5], p[5], 0xffffffffffffffff, c, c );
ADC( p[6], p[6], 0, c, c );
#endif
}
static inline void
mbedtls_p384_rum( uint64_t p[7] )
{
while( mbedtls_p384_gte( p ) )
mbedtls_p384_red( p );
}
void mbedtls_p384_mod( uint64_t X[12] )
{
secp384r1(X);
if( (int64_t)X[6] < 0 ){
do {
mbedtls_p384_gro(X);
} while( (int64_t)X[6] < 0 );
} else {
mbedtls_p384_rum(X);
}
}
static inline void
mbedtls_p384_sar( uint64_t p[7] )
{
p[0] = p[0] >> 1 | p[1] << 63;
p[1] = p[1] >> 1 | p[2] << 63;
p[2] = p[2] >> 1 | p[3] << 63;
p[3] = p[3] >> 1 | p[4] << 63;
p[4] = p[4] >> 1 | p[5] << 63;
p[5] = p[5] >> 1 | p[6] << 63;
p[6] = (int64_t)p[6] >> 1;
}
static inline void
mbedtls_p384_shl( uint64_t p[7] )
{
p[6] = p[5] >> 63;
p[5] = p[5] << 1 | p[4] >> 63;
p[4] = p[4] << 1 | p[3] >> 63;
p[3] = p[3] << 1 | p[2] >> 63;
p[2] = p[2] << 1 | p[1] >> 63;
p[1] = p[1] << 1 | p[0] >> 63;
p[0] = p[0] << 1;
mbedtls_p384_rum( p );
}
static void
mbedtls_p384_mul( uint64_t X[12],
const uint64_t A[6], size_t n,
const uint64_t B[6], size_t m )
{
if( n == 6 && m == 6 && X86_HAVE(ADX) && X86_HAVE(BMI2) )
{
Mul6x6Adx( X, A, B );
}
else
{
void *f = 0;
if( A == X )
{
A = f = memcpy( malloc( 6 * 8 ), A, 6 * 8 );
}
else if( B == X )
{
B = f = memcpy( malloc( 6 * 8 ), B, 6 * 8 );
}
Mul( X, A, n, B, m );
mbedtls_platform_zeroize( X + n + m, (12 - n - m) * 8 );
free( f );
}
mbedtls_p384_mod( X );
}
static void
mbedtls_p384_plu( uint64_t A[7],
const uint64_t B[7] )
{
#if defined(__x86_64__) && !defined(__STRICT_ANSI__)
asm("mov\t%1,%%rax\n\t"
"add\t%%rax,%0\n\t"
"mov\t8+%1,%%rax\n\t"
"adc\t%%rax,8+%0\n\t"
"mov\t16+%1,%%rax\n\t"
"adc\t%%rax,16+%0\n\t"
"mov\t24+%1,%%rax\n\t"
"adc\t%%rax,24+%0\n\t"
"mov\t32+%1,%%rax\n\t"
"adc\t%%rax,32+%0\n\t"
"mov\t40+%1,%%rax\n\t"
"adc\t%%rax,40+%0\n\t"
"mov\t48+%1,%%rax\n\t"
"adc\t%%rax,48+%0"
: /* no outputs */
: "o"(*A), "o"(*B)
: "rax", "memory", "cc");
#else
uint64_t c;
ADC( A[0], A[0], B[0], 0, c );
ADC( A[1], A[1], B[1], c, c );
ADC( A[2], A[2], B[2], c, c );
ADC( A[3], A[3], B[3], c, c );
ADC( A[4], A[4], B[4], c, c );
ADC( A[5], A[5], B[5], c, c );
ADC( A[6], A[6], B[6], c, c );
#endif
}
static void
mbedtls_p384_slu( uint64_t A[7],
const uint64_t B[7] )
{
#if defined(__x86_64__) && !defined(__STRICT_ANSI__)
asm("mov\t%1,%%rax\n\t"
"sub\t%%rax,%0\n\t"
"mov\t8+%1,%%rax\n\t"
"sbb\t%%rax,8+%0\n\t"
"mov\t16+%1,%%rax\n\t"
"sbb\t%%rax,16+%0\n\t"
"mov\t24+%1,%%rax\n\t"
"sbb\t%%rax,24+%0\n\t"
"mov\t32+%1,%%rax\n\t"
"sbb\t%%rax,32+%0\n\t"
"mov\t40+%1,%%rax\n\t"
"sbb\t%%rax,40+%0\n\t"
"mov\t48+%1,%%rax\n\t"
"sbb\t%%rax,48+%0"
: /* no outputs */
: "o"(*A), "o"(*B)
: "rax", "memory", "cc");
#else
uint64_t c;
SBB( A[0], A[0], B[0], 0, c );
SBB( A[1], A[1], B[1], c, c );
SBB( A[2], A[2], B[2], c, c );
SBB( A[3], A[3], B[3], c, c );
SBB( A[4], A[4], B[4], c, c );
SBB( A[5], A[5], B[5], c, c );
SBB( A[6], A[6], B[6], c, c );
#endif
}
static void
mbedtls_p384_add( uint64_t X[7],
const uint64_t A[6],
const uint64_t B[6] )
{
#if defined(__x86_64__) && !defined(__STRICT_ANSI__)
asm("xor\t%%rcx,%%rcx\n\t"
"mov\t%1,%%rax\n\t"
"add\t%2,%%rax\n\t"
"mov\t%%rax,%0\n\t"
"mov\t8+%1,%%rax\n\t"
"adc\t8+%2,%%rax\n\t"
"mov\t%%rax,8+%0\n\t"
"mov\t16+%1,%%rax\n\t"
"adc\t16+%2,%%rax\n\t"
"mov\t%%rax,16+%0\n\t"
"mov\t24+%1,%%rax\n\t"
"adc\t24+%2,%%rax\n\t"
"mov\t%%rax,24+%0\n\t"
"mov\t32+%1,%%rax\n\t"
"adc\t32+%2,%%rax\n\t"
"mov\t%%rax,32+%0\n\t"
"mov\t40+%1,%%rax\n\t"
"adc\t40+%2,%%rax\n\t"
"mov\t%%rax,40+%0\n\t"
"adc\t$0,%%rcx\n\t"
"mov\t%%rcx,48+%0"
: "+o"(*X)
: "o"(*A), "o"(*B)
: "rax", "rcx", "memory", "cc");
#else
uint64_t c;
ADC( X[0], A[0], B[0], 0, c );
ADC( X[1], A[1], B[1], c, c );
ADC( X[2], A[2], B[2], c, c );
ADC( X[3], A[3], B[3], c, c );
ADC( X[4], A[4], B[4], c, c );
ADC( X[5], A[5], B[5], c, X[6] );
#endif
mbedtls_p384_rum( X );
MBEDTLS_ASSERT(0 == X[6]);
}
static void
mbedtls_p384_sub( uint64_t X[7],
const uint64_t A[6],
const uint64_t B[6] )
{
#if defined(__x86_64__) && !defined(__STRICT_ANSI__)
asm("xor\t%%rcx,%%rcx\n\t"
"mov\t%1,%%rax\n\t"
"sub\t%2,%%rax\n\t"
"mov\t%%rax,%0\n\t"
"mov\t8+%1,%%rax\n\t"
"sbb\t8+%2,%%rax\n\t"
"mov\t%%rax,8+%0\n\t"
"mov\t16+%1,%%rax\n\t"
"sbb\t16+%2,%%rax\n\t"
"mov\t%%rax,16+%0\n\t"
"mov\t24+%1,%%rax\n\t"
"sbb\t24+%2,%%rax\n\t"
"mov\t%%rax,24+%0\n\t"
"mov\t32+%1,%%rax\n\t"
"sbb\t32+%2,%%rax\n\t"
"mov\t%%rax,32+%0\n\t"
"mov\t40+%1,%%rax\n\t"
"sbb\t40+%2,%%rax\n\t"
"mov\t%%rax,40+%0\n\t"
"sbb\t$0,%%rcx\n\t"
"mov\t%%rcx,48+%0"
: "+o"(*X)
: "o"(*A), "o"(*B)
: "rax", "rcx", "memory", "cc");
#else
uint64_t c;
SBB( X[0], A[0], B[0], 0, c );
SBB( X[1], A[1], B[1], c, c );
SBB( X[2], A[2], B[2], c, c );
SBB( X[3], A[3], B[3], c, c );
SBB( X[4], A[4], B[4], c, c );
SBB( X[5], A[5], B[5], c, c );
X[6] = -c;
#endif
while( (int64_t)X[6] < 0 )
mbedtls_p384_gro( X );
MBEDTLS_ASSERT(0 == X[6]);
}
static void
mbedtls_p384_hub( uint64_t A[7],
const uint64_t B[6] )
{
#if defined(__x86_64__) && !defined(__STRICT_ANSI__)
asm("xor\t%%rcx,%%rcx\n\t"
"mov\t%1,%%rax\n\t"
"sub\t%%rax,%0\n\t"
"mov\t8+%1,%%rax\n\t"
"sbb\t%%rax,8+%0\n\t"
"mov\t16+%1,%%rax\n\t"
"sbb\t%%rax,16+%0\n\t"
"mov\t24+%1,%%rax\n\t"
"sbb\t%%rax,24+%0\n\t"
"mov\t32+%1,%%rax\n\t"
"sbb\t%%rax,32+%0\n\t"
"mov\t40+%1,%%rax\n\t"
"sbb\t%%rax,40+%0\n\t"
"sbb\t$0,%%rcx\n\t"
"mov\t%%rcx,48+%0"
: "+o"(*A)
: "o"(*B)
: "rax", "rcx", "memory", "cc");
while( (int64_t)A[6] < 0 )
mbedtls_p384_gro( A );
MBEDTLS_ASSERT(0 == A[6]);
#else
mbedtls_p384_sub(A, A, B);
#endif
}
static inline void
mbedtls_p384_cop( uint64_t X[6],
const uint64_t Y[6] )
{
memcpy( X, Y, 6*8 );
}
static int
mbedtls_p384_dim( mbedtls_ecp_point *R )
{
int ret;
if( R->X.n < 6 && ( ret = mbedtls_mpi_grow( &R->X, 6 ) ) ) return( ret );
if( R->Y.n < 6 && ( ret = mbedtls_mpi_grow( &R->Y, 6 ) ) ) return( ret );
if( R->Z.n < 6 && ( ret = mbedtls_mpi_grow( &R->Z, 6 ) ) ) return( ret );
return( 0 );
}
int mbedtls_p384_double_jac( const mbedtls_ecp_group *G,
const mbedtls_ecp_point *P,
mbedtls_ecp_point *R )
{
int ret;
uint64_t T[4][12];
if( ( ret = mbedtls_p384_dim( R ) ) ) return( ret );
if( ( ret = mbedtls_p384_dim( (void *)P ) ) ) return( ret );
mbedtls_platform_zeroize( T, sizeof( T ) );
mbedtls_p384_mul( T[1], P->Z.p, 6, P->Z.p, 6 );
mbedtls_p384_add( T[2], P->X.p, T[1] );
mbedtls_p384_sub( T[3], P->X.p, T[1] );
mbedtls_p384_mul( T[1], T[2], 6, T[3], 6 );
mbedtls_mpi_mul_hlp1( 6, T[1], T[0], 3 );
mbedtls_p384_rum( T[0] );
mbedtls_p384_mul( T[2], P->Y.p, 6, P->Y.p, 6 );
mbedtls_p384_shl( T[2] );
mbedtls_p384_mul( T[1], P->X.p, 6, T[2], 6 );
mbedtls_p384_shl( T[1] );
mbedtls_p384_mul( T[3], T[2], 6, T[2], 6 );
mbedtls_p384_shl( T[3] );
mbedtls_p384_mul( T[2], T[0], 6, T[0], 6 );
mbedtls_p384_hub( T[2], T[1] );
mbedtls_p384_hub( T[2], T[1] );
mbedtls_p384_hub( T[1], T[2] );
mbedtls_p384_mul( T[1], T[1], 6, T[0], 6 );
mbedtls_p384_hub( T[1], T[3] );
mbedtls_p384_mul( T[3], P->Y.p, 6, P->Z.p, 6 );
mbedtls_p384_shl( T[3] );
mbedtls_p384_cop( R->X.p, T[2] );
mbedtls_p384_cop( R->Y.p, T[1] );
mbedtls_p384_cop( R->Z.p, T[3] );
return( 0 );
}
int mbedtls_p384_add_mixed( const mbedtls_ecp_group *G,
const mbedtls_ecp_point *P,
const mbedtls_ecp_point *Q,
mbedtls_ecp_point *R )
{
int ret;
struct {
uint64_t X[12], Y[12], Z[12];
uint64_t T1[12], T2[12], T3[12], T4[12];
size_t Xn, Yn, Zn, QXn, QYn;
} s;
if( ( ret = mbedtls_p384_dim( R ) ) ) return( ret );
mbedtls_platform_zeroize( &s, sizeof( s ) );
s.Xn = mbedtls_mpi_limbs( &P->X );
s.Yn = mbedtls_mpi_limbs( &P->Y );
s.Zn = mbedtls_mpi_limbs( &P->Z );
s.QXn = mbedtls_mpi_limbs( &Q->X );
s.QYn = mbedtls_mpi_limbs( &Q->Y );
MBEDTLS_ASSERT( s.Xn <= 6 );
MBEDTLS_ASSERT( s.Yn <= 6 );
MBEDTLS_ASSERT( s.Zn <= 6 );
MBEDTLS_ASSERT( s.QXn <= 6 );
MBEDTLS_ASSERT( s.QYn <= 6 );
memcpy( s.X, P->X.p, s.Xn * 8 );
memcpy( s.Y, P->Y.p, s.Yn * 8 );
memcpy( s.Z, P->Z.p, s.Zn * 8 );
mbedtls_p384_mul( s.T1, s.Z, s.Zn, s.Z, s.Zn );
mbedtls_p384_mul( s.T2, s.T1, 6, s.Z, s.Zn );
mbedtls_p384_mul( s.T1, s.T1, 6, Q->X.p, s.QXn );
mbedtls_p384_mul( s.T2, s.T2, 6, Q->Y.p, s.QYn );
mbedtls_p384_hub( s.T1, s.X );
mbedtls_p384_hub( s.T2, s.Y );
if( mbedtls_p384_isz( s.T1 ) )
{
if( mbedtls_p384_isz( s.T2 ) )
return( mbedtls_p384_double_jac( G, P, R ) );
else
return( mbedtls_ecp_set_zero( R ) );
}
mbedtls_p384_mul( s.Z, s.Z, s.Zn, s.T1, 6 );
mbedtls_p384_mul( s.T3, s.T1, 6, s.T1, 6 );
mbedtls_p384_mul( s.T4, s.T3, 6, s.T1, 6 );
mbedtls_p384_mul( s.T3, s.T3, 6, s.X, s.Xn );
mbedtls_p384_cop( s.T1, s.T3 );
mbedtls_p384_shl( s.T1 );
mbedtls_p384_mul( s.X, s.T2, 6, s.T2, 6 );
mbedtls_p384_hub( s.X, s.T1 );
mbedtls_p384_hub( s.X, s.T4 );
mbedtls_p384_hub( s.T3, s.X );
mbedtls_p384_mul( s.T3, s.T3, 6, s.T2, 6 );
mbedtls_p384_mul( s.T4, s.T4, 6, s.Y, s.Yn );
mbedtls_p384_sub( s.Y, s.T3, s.T4 );
mbedtls_p384_cop( R->X.p, s.X );
mbedtls_p384_cop( R->Y.p, s.Y );
mbedtls_p384_cop( R->Z.p, s.Z );
mbedtls_platform_zeroize( &s, sizeof( s ) );
return( 0 );
}
static void
mbedtls_p384_inv( uint64_t X[6],
const uint64_t A[6],
const uint64_t N[6] )
{
uint64_t TA[7], TU[7], TV[7], UV[4][7];
mbedtls_platform_zeroize( UV, sizeof( UV ) );
*(uint64_t *)mempcpy( TA, A, 6*8 ) = 0;
*(uint64_t *)mempcpy( TU, A, 6*8 ) = 0;
*(uint64_t *)mempcpy( TV, N, 6*8 ) = 0;
UV[0][0] = 1;
UV[3][0] = 1;
do {
while( ~TU[0] & 1 ){
mbedtls_p384_sar( TU );
if( ( UV[0][0] | UV[1][0] ) & 1 ){
mbedtls_p384_gro( UV[0] );
mbedtls_p384_slu( UV[1], TA );
}
mbedtls_p384_sar( UV[0] );
mbedtls_p384_sar( UV[1] );
}
while( ~TV[0] & 1 ){
mbedtls_p384_sar( TV );
if( ( UV[2][0] | UV[3][0] ) & 1 ){
mbedtls_p384_gro( UV[2] );
mbedtls_p384_slu( UV[3], TA );
}
mbedtls_p384_sar( UV[2] );
mbedtls_p384_sar( UV[3] );
}
if( mbedtls_p384_cmp( TU, TV ) >= 0 ){
mbedtls_p384_slu( TU, TV );
mbedtls_p384_slu( UV[0], UV[2] );
mbedtls_p384_slu( UV[1], UV[3] );
} else {
mbedtls_p384_slu( TV, TU );
mbedtls_p384_slu( UV[2], UV[0] );
mbedtls_p384_slu( UV[3], UV[1] );
}
} while( TU[0] | TU[1] | TU[2] | TU[3] | TU[4] | TU[5] | TU[6] );
while( (int64_t)UV[2][6] < 0 )
mbedtls_p384_gro( UV[2] );
while( mbedtls_p384_gte( UV[2] ) )
mbedtls_p384_red( UV[2] );
mbedtls_p384_cop( X, UV[2] );
}
int mbedtls_p384_normalize_jac( const mbedtls_ecp_group *grp,
mbedtls_ecp_point *pt )
{
int ret;
uint64_t t[12], Zi[12], ZZi[12];
if(( ret = mbedtls_p384_dim(pt)) ) return( ret );
mbedtls_p384_inv( Zi, pt->Z.p, grp->P.p );
mbedtls_p384_mul( ZZi, Zi, 6, Zi, 6 );
mbedtls_p384_mul( t, pt->X.p, 6, ZZi, 6 );
mbedtls_p384_cop( pt->X.p, t );
mbedtls_p384_mul( t, pt->Y.p, 6, ZZi, 6 );
mbedtls_p384_mul( t, t, 6, Zi, 6 );
mbedtls_p384_cop( pt->Y.p, t );
mbedtls_mpi_lset( &pt->Z, 1 );
return( 0 );
}
int mbedtls_p384_normalize_jac_many( const mbedtls_ecp_group *grp,
mbedtls_ecp_point *T[], size_t n )
{
size_t i;
uint64_t *c, u[12], ta[12], Zi[12], ZZi[12];
if( !( c = mbedtls_calloc( n, 12*8 ) ) )
return( MBEDTLS_ERR_ECP_ALLOC_FAILED );
memcpy( c, T[0]->Z.p, T[0]->Z.n*8 );
for( i = 1; i < n; i++ )
mbedtls_p384_mul( c+i*12, c+(i-1)*12, 6, T[i]->Z.p, 6 );
mbedtls_p384_inv( u, c+(n-1)*12, grp->P.p );
for( i = n - 1; ; i-- ){
if( !i ){
mbedtls_p384_cop( Zi, u );
} else {
mbedtls_p384_mul( Zi, u, 6, c+(i-1)*12, 6 );
mbedtls_p384_mul( u, u, 6, T[i]->Z.p, 6 );
}
mbedtls_p384_mul( ZZi, Zi, 6, Zi, 6 );
mbedtls_p384_mul( ta, T[i]->X.p, 6, ZZi, 6 );
memcpy( T[i]->X.p, ta, 6 * 8 );
mbedtls_p384_mul( ta, T[i]->Y.p, 6, ZZi, 6 );
mbedtls_p384_mul( ta, ta, 6, Zi, 6 );
memcpy( T[i]->Y.p, ta, 6 * 8 );
mbedtls_mpi_free( &T[i]->Z );
if( !i ) break;
}
mbedtls_platform_zeroize( ta, sizeof( ta ) );
mbedtls_platform_zeroize( c, n*12*8 );
mbedtls_free( c );
return( 0 );
}