yuzu/mbedtls
1
0
Fork 0
mirror of https://github.com/yuzu-emu/mbedtls.git synced 2025-01-25 18:31:06 +00:00
Code Issues Packages Projects Releases Wiki Activity

Add mod_p256

Browse source
This commit is contained in:
Manuel Pégourié-Gonnard 2013-10-23 14:50:39 +02:00
parent 210b458ddc
commit ec655c908c
1 changed files with 38 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

38
library/ecp.c
View file

@ -705,6 +705,43 @@ cleanup:
} }
#endif /* POLARSSL_ECP_DP_SECP224R1_ENABLED */ #endif /* POLARSSL_ECP_DP_SECP224R1_ENABLED */
#if defined(POLARSSL_ECP_DP_SECP256R1_ENABLED)
/*
* Fast quasi-reduction modulo p256 (FIPS 186-3 D.2.3)
*/
static int ecp_mod_p256( mpi *N )
{
INIT( 256 );
ADD( 8 ); ADD( 9 );
SUB( 11 ); SUB( 12 ); SUB( 13 ); SUB( 14 ); NEXT; // A0
ADD( 9 ); ADD( 10 );
SUB( 12 ); SUB( 13 ); SUB( 14 ); SUB( 15 ); NEXT; // A1
ADD( 10 ); ADD( 11 );
SUB( 13 ); SUB( 14 ); SUB( 15 ); NEXT; // A2
ADD( 11 ); ADD( 11 ); ADD( 12 ); ADD( 12 ); ADD( 13 );
SUB( 15 ); SUB( 8 ); SUB( 9 ); NEXT; // A3
ADD( 12 ); ADD( 12 ); ADD( 13 ); ADD( 13 ); ADD( 14 );
SUB( 9 ); SUB( 10 ); NEXT; // A4
ADD( 13 ); ADD( 13 ); ADD( 14 ); ADD( 14 ); ADD( 15 );
SUB( 10 ); SUB( 11 ); NEXT; // A5
ADD( 14 ); ADD( 14 ); ADD( 15 ); ADD( 15 ); ADD( 14 ); ADD( 13 );
SUB( 8 ); SUB( 9 ); NEXT; // A6
ADD( 15 ); ADD( 15 ); ADD( 15 ); ADD( 8 );
SUB( 10 ); SUB( 11 ); SUB( 12 ); SUB( 13 ); LAST; // A7
cleanup:
return( ret );
}
#endif /* POLARSSL_ECP_DP_SECP256R1_ENABLED */
#if defined(POLARSSL_ECP_DP_SECP224R1_ENABLED) || \ #if defined(POLARSSL_ECP_DP_SECP224R1_ENABLED) || \
defined(POLARSSL_ECP_DP_SECP256R1_ENABLED) || \ defined(POLARSSL_ECP_DP_SECP256R1_ENABLED) || \
defined(POLARSSL_ECP_DP_SECP384R1_ENABLED) defined(POLARSSL_ECP_DP_SECP384R1_ENABLED)
@ -951,6 +988,7 @@ int ecp_use_known_dp( ecp_group *grp, ecp_group_id id )
#if defined(POLARSSL_ECP_DP_SECP256R1_ENABLED) #if defined(POLARSSL_ECP_DP_SECP256R1_ENABLED)
case POLARSSL_ECP_DP_SECP256R1: case POLARSSL_ECP_DP_SECP256R1:
grp->modp = ecp_mod_p256;
return( ecp_group_read_string( grp, 16, return( ecp_group_read_string( grp, 16,
SECP256R1_P, SECP256R1_B, SECP256R1_P, SECP256R1_B,
SECP256R1_GX, SECP256R1_GY, SECP256R1_N ) ); SECP256R1_GX, SECP256R1_GY, SECP256R1_N ) );