Commit 773ed546 by Manuel Pégourié-Gonnard Committed by Paul Bakker

### Added a nbits member to ecp_group

parent 4bdd47d2
 ... ... @@ -52,18 +52,17 @@ ecp_point; /** * \brief ECP group structure * * The curves we consider are defined by y^2 = x^3 - 3x + b mod p, * and a generator for a large subgroup is fixed. * The curves we consider are defined by y^2 = x^3 - 3x + B mod P, * and a generator for a large subgroup of order N is fixed. * * If modp is NULL, pbits will not be used, and reduction modulo P is * done using a generic algorithm. * pbits and nbits must be the size of P and N in bits. * * If modp is not NULL, pbits must be the size of P in bits and modp * must be a function that takes an mpi in the range 0..2^(2*pbits) and * transforms it in-place in an integer of little more than pbits, so * that the integer may be efficiently brought in the 0..P range by a * few additions or substractions. It must return 0 on success and a * POLARSSL_ERR_ECP_XXX error on failure. * If modp is NULL, reduction modulo P is done using a generic * algorithm. Otherwise, it must point to a function that takes an mpi * in the range 0..2^(2*pbits) and transforms it in-place in an integer * of little more than pbits, so that the integer may be efficiently * brought in the 0..P range by a few additions or substractions. It * must return 0 on success and a POLARSSL_ERR_ECP_XXX error on failure. */ typedef struct { ... ... @@ -71,8 +70,9 @@ typedef struct mpi B; /*!< constant term in the equation */ ecp_point G; /*!< generator of the subgroup used */ mpi N; /*!< the order of G */ size_t pbits; /*!< number of bits in P */ size_t nbits; /*!< number of bits in N */ int (*modp)(mpi *); /*!< function for fast reduction mod P */ unsigned pbits; /*!< number of bits in P */ } ecp_group; ... ... @@ -158,6 +158,8 @@ int ecp_point_read_string( ecp_point *P, int radix, * \param n The generator's order * * \return 0 if successful, or a POLARSSL_ERR_MPI_XXX error code * * \note Sets all fields except modp. */ int ecp_group_read_string( ecp_group *grp, int radix, const char *p, const char *b, ... ...
 ... ... @@ -64,8 +64,10 @@ void ecp_group_init( ecp_group *grp ) ecp_point_init( &grp->G ); mpi_init( &grp->N ); grp->modp = NULL; grp->pbits = 0; grp->nbits = 0; grp->modp = NULL; } /* ... ... @@ -155,12 +157,16 @@ int ecp_group_read_string( ecp_group *grp, int radix, MPI_CHK( ecp_point_read_string( &grp->G, radix, gx, gy ) ); MPI_CHK( mpi_read_string( &grp->N, radix, n ) ); grp->pbits = mpi_msb( &grp->P ); grp->nbits = mpi_msb( &grp->N ); cleanup: return( ret ); } /* * Wrapper around fast quasi-modp functions, with fall-back to mpi_mod_mpi * Wrapper around fast quasi-modp functions, with fall-back to mpi_mod_mpi. * See the documentation of struct ecp_group. */ static int ecp_modp( mpi *N, const ecp_group *grp ) { ... ... @@ -394,7 +400,6 @@ int ecp_use_known_dp( ecp_group *grp, size_t index ) { case POLARSSL_ECP_DP_SECP192R1: grp->modp = ecp_mod_p192; grp->pbits = 192; return( ecp_group_read_string( grp, 16, SECP192R1_P, SECP192R1_B, SECP192R1_GX, SECP192R1_GY, SECP192R1_N ) ); ... ... @@ -416,7 +421,6 @@ int ecp_use_known_dp( ecp_group *grp, size_t index ) case POLARSSL_ECP_DP_SECP521R1: grp->modp = ecp_mod_p521; grp->pbits = 521; return( ecp_group_read_string( grp, 16, SECP521R1_P, SECP521R1_B, SECP521R1_GX, SECP521R1_GY, SECP521R1_N ) ); ... ...
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