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https://github.com/yuzu-emu/mbedtls.git
synced 2024-11-26 01:05:40 +01:00
Clarifications in comments; code cosmetics & style
This commit is contained in:
Manuel Pégourié-Gonnard
Paul Bakker
parent
dada4da33f
commit
4712325777
@ -55,7 +55,15 @@ ecp_point;
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* The curves we consider are defined by y^2 = x^3 - 3x + b mod p,
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* and a generator for a large subgroup is fixed.
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*
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* modp may be NULL; pbits will not be used in this case.
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* If modp is NULL, pbits will not be used, and reduction modulo P is
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* done using a generic algorithm.
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*
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* If modp is not NULL, pbits must be the size of P in bits and modp
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* must be a function that takes an mpi in the range 0..2^(2*pbits) and
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* transforms it in-place in an integer of little more than pbits, so
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* that the integer may be efficiently brought in the 0..P range by a
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* few additions or substractions. It must return 0 on success and a
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* POLARSSL_ERR_ECP_XXX error on failure.
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*/
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typedef struct
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{
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@ -77,7 +85,7 @@ ecp_group;
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*
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* \warning This library does not support validation of arbitrary domain
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* parameters. Therefore, only well-known domain parameters from trusted
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* sources (such as the ones below) should be used. See ecp_use_known_dp().
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* sources should be used. See ecp_use_known_dp().
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*/
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#define POLARSSL_ECP_DP_SECP192R1 0
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#define POLARSSL_ECP_DP_SECP224R1 1
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@ -161,7 +169,7 @@ int ecp_group_read_string( ecp_group *grp, int radix,
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* \param grp Destination group
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* \param index Index in the list of well-known domain parameters
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*
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* \return O if successul,
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* \return O if successful,
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* POLARSSL_ERR_MPI_XXX if initialization failed
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* POLARSSL_ERR_ECP_GENERIC if index is out of range
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*
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118
library/ecp.c
118
library/ecp.c
@ -109,11 +109,11 @@ void ecp_set_zero( ecp_point *pt )
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*/
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int ecp_copy( ecp_point *P, const ecp_point *Q )
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{
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int ret = 0;
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int ret;
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if( Q->is_zero ) {
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ecp_set_zero( P );
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return( ret );
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return( 0 );
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}
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P->is_zero = Q->is_zero;
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@ -130,7 +130,7 @@ cleanup:
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int ecp_point_read_string( ecp_point *P, int radix,
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const char *x, const char *y )
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{
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int ret = 0;
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int ret;
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P->is_zero = 0;
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MPI_CHK( mpi_read_string( &P->X, radix, x ) );
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@ -147,7 +147,7 @@ int ecp_group_read_string( ecp_group *grp, int radix,
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const char *p, const char *b,
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const char *gx, const char *gy, const char *n)
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{
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int ret = 0;
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int ret;
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MPI_CHK( mpi_read_string( &grp->P, radix, p ) );
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MPI_CHK( mpi_read_string( &grp->B, radix, b ) );
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@ -159,15 +159,11 @@ cleanup:
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}
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/*
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* Wrapper around fast quasi-modp functions, with fallback to mpi_mod_mpi
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*
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* The quasi-modp functions expect an mpi N such that 0 <= N < 2^(2*pbits)
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* and change it in-place so that it can easily be brought in the 0..P-1
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* range by a few additions or substractions.
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* Wrapper around fast quasi-modp functions, with fall-back to mpi_mod_mpi
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*/
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static int ecp_modp( mpi *N, const ecp_group *grp )
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{
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int ret = 0;
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int ret;
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if( grp->modp == NULL )
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return( mpi_mod_mpi( N, N, &grp->P ) );
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@ -206,7 +202,7 @@ cleanup:
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*/
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static int ecp_mod_p521( mpi *N )
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{
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int ret = 0;
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int ret;
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t_uint Mp[P521_SIZE_INT];
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mpi M;
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@ -353,13 +349,13 @@ int ecp_use_known_dp( ecp_group *grp, size_t index )
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}
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/*
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* Fast mod-p functions expect an argument in the 0 .. p^2 range.
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* Fast mod-p functions expect their argument to be in the 0..p^2 range.
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*
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* In order to garantee that, we need to ensure that operands of
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* mpi_mul_mpi are in the 0 .. p range. So, after each operation we will
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* In order to guarantee that, we need to ensure that operands of
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* mpi_mul_mpi are in the 0..p range. So, after each operation we will
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* bring the result back to this range.
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*
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* The following macros are helpers for that.
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* The following macros are shortcuts for doing that.
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*/
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/*
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@ -412,7 +408,7 @@ static void ecp_ptjac_free( ecp_ptjac *P )
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*/
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static int ecp_ptjac_copy( ecp_ptjac *R, const ecp_ptjac *P )
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{
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int ret = 0;
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int ret;
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MPI_CHK( mpi_copy( &R->X, &P->X ) );
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MPI_CHK( mpi_copy( &R->Y, &P->Y ) );
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@ -427,7 +423,7 @@ cleanup:
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*/
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static int ecp_ptjac_set_zero( ecp_ptjac *P )
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{
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int ret = 0;
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int ret;
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MPI_CHK( mpi_lset( &P->X, 1 ) );
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MPI_CHK( mpi_lset( &P->Y, 1 ) );
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@ -442,7 +438,7 @@ cleanup:
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*/
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static int ecp_aff_to_jac( ecp_ptjac *jac, const ecp_point *aff )
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{
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int ret = 0;
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int ret;
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if( aff->is_zero )
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return( ecp_ptjac_set_zero( jac ) );
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@ -461,7 +457,7 @@ cleanup:
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static int ecp_jac_to_aff( const ecp_group *grp,
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ecp_point *aff, const ecp_ptjac *jac )
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{
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int ret = 0;
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int ret;
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mpi Zi, ZZi, T;
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if( mpi_cmp_int( &jac->Z, 0 ) == 0 ) {
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@ -499,7 +495,7 @@ cleanup:
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static int ecp_double_jac( const ecp_group *grp, ecp_ptjac *R,
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const ecp_ptjac *P )
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{
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int ret = 0;
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int ret;
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mpi T1, T2, T3, X, Y, Z;
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if( mpi_cmp_int( &P->Z, 0 ) == 0 )
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@ -508,17 +504,16 @@ static int ecp_double_jac( const ecp_group *grp, ecp_ptjac *R,
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mpi_init( &T1 ); mpi_init( &T2 ); mpi_init( &T3 );
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mpi_init( &X ); mpi_init( &Y ); mpi_init( &Z );
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MPI_CHK( mpi_mul_mpi( &T1, &P->Z, &P->Z ) ); MOD_MUL( T1 );
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MPI_CHK( mpi_sub_mpi( &T2, &P->X, &T1 ) ); MOD_SUB( T2 );
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MPI_CHK( mpi_add_mpi( &T1, &P->X, &T1 ) ); MOD_ADD( T1 );
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MPI_CHK( mpi_mul_mpi( &T2, &T2, &T1 ) ); MOD_MUL( T2 );
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MPI_CHK( mpi_mul_int( &T2, &T2, 3 ) ); MOD_ADD( T2 );
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MPI_CHK( mpi_copy ( &Y, &P->Y ) );
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MPI_CHK( mpi_shift_l( &Y, 1 ) ); MOD_ADD( Y );
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MPI_CHK( mpi_mul_mpi( &Z, &Y, &P->Z ) ); MOD_MUL( Z );
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MPI_CHK( mpi_mul_mpi( &Y, &Y, &Y ) ); MOD_MUL( Y );
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MPI_CHK( mpi_mul_mpi( &T3, &Y, &P->X ) ); MOD_MUL( T3 );
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MPI_CHK( mpi_mul_mpi( &Y, &Y, &Y ) ); MOD_MUL( Y );
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MPI_CHK( mpi_mul_mpi( &T1, &P->Z, &P->Z ) ); MOD_MUL( T1 );
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MPI_CHK( mpi_sub_mpi( &T2, &P->X, &T1 ) ); MOD_SUB( T2 );
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MPI_CHK( mpi_add_mpi( &T1, &P->X, &T1 ) ); MOD_ADD( T1 );
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MPI_CHK( mpi_mul_mpi( &T2, &T2, &T1 ) ); MOD_MUL( T2 );
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MPI_CHK( mpi_mul_int( &T2, &T2, 3 ) ); MOD_ADD( T2 );
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MPI_CHK( mpi_mul_int( &Y, &P->Y, 2 ) ); MOD_ADD( Y );
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MPI_CHK( mpi_mul_mpi( &Z, &Y, &P->Z ) ); MOD_MUL( Z );
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MPI_CHK( mpi_mul_mpi( &Y, &Y, &Y ) ); MOD_MUL( Y );
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MPI_CHK( mpi_mul_mpi( &T3, &Y, &P->X ) ); MOD_MUL( T3 );
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MPI_CHK( mpi_mul_mpi( &Y, &Y, &Y ) ); MOD_MUL( Y );
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/*
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* For Y = Y / 2 mod p, we must make sure that Y is even before
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@ -528,13 +523,12 @@ static int ecp_double_jac( const ecp_group *grp, ecp_ptjac *R,
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MPI_CHK( mpi_add_mpi( &Y, &Y, &grp->P ) );
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MPI_CHK( mpi_shift_r( &Y, 1 ) );
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MPI_CHK( mpi_mul_mpi( &X, &T2, &T2 ) ); MOD_MUL( X );
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MPI_CHK( mpi_copy ( &T1, &T3 ) );
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MPI_CHK( mpi_shift_l( &T1, 1 ) ); MOD_ADD( T1 );
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MPI_CHK( mpi_sub_mpi( &X, &X, &T1 ) ); MOD_SUB( X );
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MPI_CHK( mpi_sub_mpi( &T1, &T3, &X ) ); MOD_SUB( T1 );
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MPI_CHK( mpi_mul_mpi( &T1, &T1, &T2 ) ); MOD_MUL( T1 );
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MPI_CHK( mpi_sub_mpi( &Y, &T1, &Y ) ); MOD_SUB( Y );
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MPI_CHK( mpi_mul_mpi( &X, &T2, &T2 ) ); MOD_MUL( X );
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MPI_CHK( mpi_mul_int( &T1, &T3, 2 ) ); MOD_ADD( T1 );
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MPI_CHK( mpi_sub_mpi( &X, &X, &T1 ) ); MOD_SUB( X );
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MPI_CHK( mpi_sub_mpi( &T1, &T3, &X ) ); MOD_SUB( T1 );
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MPI_CHK( mpi_mul_mpi( &T1, &T1, &T2 ) ); MOD_MUL( T1 );
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MPI_CHK( mpi_sub_mpi( &Y, &T1, &Y ) ); MOD_SUB( Y );
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MPI_CHK( mpi_copy( &R->X, &X ) );
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MPI_CHK( mpi_copy( &R->Y, &Y ) );
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@ -554,7 +548,7 @@ cleanup:
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static int ecp_add_mixed( const ecp_group *grp, ecp_ptjac *R,
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const ecp_ptjac *P, const ecp_point *Q )
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{
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int ret = 0;
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int ret;
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mpi T1, T2, T3, T4, X, Y, Z;
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/*
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@ -569,12 +563,12 @@ static int ecp_add_mixed( const ecp_group *grp, ecp_ptjac *R,
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mpi_init( &T1 ); mpi_init( &T2 ); mpi_init( &T3 ); mpi_init( &T4 );
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mpi_init( &X ); mpi_init( &Y ); mpi_init( &Z );
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MPI_CHK( mpi_mul_mpi( &T1, &P->Z, &P->Z ) ); MOD_MUL( T1 );
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MPI_CHK( mpi_mul_mpi( &T2, &T1, &P->Z ) ); MOD_MUL( T2 );
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MPI_CHK( mpi_mul_mpi( &T1, &T1, &Q->X ) ); MOD_MUL( T1 );
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MPI_CHK( mpi_mul_mpi( &T2, &T2, &Q->Y ) ); MOD_MUL( T2 );
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MPI_CHK( mpi_sub_mpi( &T1, &T1, &P->X ) ); MOD_SUB( T1 );
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MPI_CHK( mpi_sub_mpi( &T2, &T2, &P->Y ) ); MOD_SUB( T2 );
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MPI_CHK( mpi_mul_mpi( &T1, &P->Z, &P->Z ) ); MOD_MUL( T1 );
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MPI_CHK( mpi_mul_mpi( &T2, &T1, &P->Z ) ); MOD_MUL( T2 );
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MPI_CHK( mpi_mul_mpi( &T1, &T1, &Q->X ) ); MOD_MUL( T1 );
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MPI_CHK( mpi_mul_mpi( &T2, &T2, &Q->Y ) ); MOD_MUL( T2 );
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MPI_CHK( mpi_sub_mpi( &T1, &T1, &P->X ) ); MOD_SUB( T1 );
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MPI_CHK( mpi_sub_mpi( &T2, &T2, &P->Y ) ); MOD_SUB( T2 );
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if( mpi_cmp_int( &T1, 0 ) == 0 )
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{
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@ -590,18 +584,18 @@ static int ecp_add_mixed( const ecp_group *grp, ecp_ptjac *R,
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}
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}
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MPI_CHK( mpi_mul_mpi( &Z, &P->Z, &T1 ) ); MOD_MUL( Z );
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MPI_CHK( mpi_mul_mpi( &T3, &T1, &T1 ) ); MOD_MUL( T3 );
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MPI_CHK( mpi_mul_mpi( &T4, &T3, &T1 ) ); MOD_MUL( T4 );
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MPI_CHK( mpi_mul_mpi( &T3, &T3, &P->X ) ); MOD_MUL( T3 );
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MPI_CHK( mpi_mul_int( &T1, &T3, 2 ) ); MOD_ADD( T1 );
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MPI_CHK( mpi_mul_mpi( &X, &T2, &T2 ) ); MOD_MUL( X );
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MPI_CHK( mpi_sub_mpi( &X, &X, &T1 ) ); MOD_SUB( X );
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MPI_CHK( mpi_sub_mpi( &X, &X, &T4 ) ); MOD_SUB( X );
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MPI_CHK( mpi_sub_mpi( &T3, &T3, &X ) ); MOD_SUB( T3 );
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MPI_CHK( mpi_mul_mpi( &T3, &T3, &T2 ) ); MOD_MUL( T3 );
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MPI_CHK( mpi_mul_mpi( &T4, &T4, &P->Y ) ); MOD_MUL( T4 );
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MPI_CHK( mpi_sub_mpi( &Y, &T3, &T4 ) ); MOD_SUB( Y );
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MPI_CHK( mpi_mul_mpi( &Z, &P->Z, &T1 ) ); MOD_MUL( Z );
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MPI_CHK( mpi_mul_mpi( &T3, &T1, &T1 ) ); MOD_MUL( T3 );
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MPI_CHK( mpi_mul_mpi( &T4, &T3, &T1 ) ); MOD_MUL( T4 );
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MPI_CHK( mpi_mul_mpi( &T3, &T3, &P->X ) ); MOD_MUL( T3 );
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MPI_CHK( mpi_mul_int( &T1, &T3, 2 ) ); MOD_ADD( T1 );
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MPI_CHK( mpi_mul_mpi( &X, &T2, &T2 ) ); MOD_MUL( X );
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MPI_CHK( mpi_sub_mpi( &X, &X, &T1 ) ); MOD_SUB( X );
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MPI_CHK( mpi_sub_mpi( &X, &X, &T4 ) ); MOD_SUB( X );
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MPI_CHK( mpi_sub_mpi( &T3, &T3, &X ) ); MOD_SUB( T3 );
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MPI_CHK( mpi_mul_mpi( &T3, &T3, &T2 ) ); MOD_MUL( T3 );
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MPI_CHK( mpi_mul_mpi( &T4, &T4, &P->Y ) ); MOD_MUL( T4 );
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MPI_CHK( mpi_sub_mpi( &Y, &T3, &T4 ) ); MOD_SUB( Y );
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MPI_CHK( mpi_copy( &R->X, &X ) );
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MPI_CHK( mpi_copy( &R->Y, &Y ) );
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@ -621,7 +615,7 @@ cleanup:
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int ecp_add( const ecp_group *grp, ecp_point *R,
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const ecp_point *P, const ecp_point *Q )
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{
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int ret = 0;
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int ret;
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ecp_ptjac J;
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ecp_ptjac_init( &J );
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@ -643,20 +637,20 @@ cleanup:
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int ecp_mul( const ecp_group *grp, ecp_point *R,
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const mpi *m, const ecp_point *P )
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{
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int ret = 0;
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int ret;
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size_t pos;
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ecp_ptjac Q[2];
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ecp_ptjac_init( &Q[0] ); ecp_ptjac_init( &Q[1] );
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/*
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* The general method works only for m >= 1
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*/
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if( mpi_cmp_int( m, 0 ) == 0 ) {
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ecp_set_zero( R );
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goto cleanup;
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return( 0 );
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}
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ecp_ptjac_init( &Q[0] ); ecp_ptjac_init( &Q[1] );
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ecp_ptjac_set_zero( &Q[0] );
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for( pos = mpi_msb( m ) - 1 ; ; pos-- )
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