/* BEGIN_HEADER */
#include "mbedtls/ecdsa.h"
/* END_HEADER */

/* BEGIN_DEPENDENCIES
 * depends_on:MBEDTLS_ECDSA_C
 * END_DEPENDENCIES
 */

/* BEGIN_CASE */
void ecdsa_prim_random( int id )
{
    mbedtls_ecp_group grp;
    mbedtls_ecp_point Q;
    mbedtls_mpi d, r, s;
    rnd_pseudo_info rnd_info;
    unsigned char buf[66];

    mbedtls_ecp_group_init( &grp );
    mbedtls_ecp_point_init( &Q );
    mbedtls_mpi_init( &d ); mbedtls_mpi_init( &r ); mbedtls_mpi_init( &s );
    memset( &rnd_info, 0x00, sizeof( rnd_pseudo_info ) );
    memset( buf, 0, sizeof( buf ) );

    /* prepare material for signature */
    TEST_ASSERT( rnd_pseudo_rand( &rnd_info, buf, sizeof( buf ) ) == 0 );
    TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
    TEST_ASSERT( mbedtls_ecp_gen_keypair( &grp, &d, &Q, &rnd_pseudo_rand, &rnd_info )
                 == 0 );

    TEST_ASSERT( mbedtls_ecdsa_sign( &grp, &r, &s, &d, buf, sizeof( buf ),
                             &rnd_pseudo_rand, &rnd_info ) == 0 );
    TEST_ASSERT( mbedtls_ecdsa_verify( &grp, buf, sizeof( buf ), &Q, &r, &s ) == 0 );

exit:
    mbedtls_ecp_group_free( &grp );
    mbedtls_ecp_point_free( &Q );
    mbedtls_mpi_free( &d ); mbedtls_mpi_free( &r ); mbedtls_mpi_free( &s );
}
/* END_CASE */

/* BEGIN_CASE */
void ecdsa_prim_test_vectors( int id, char * d_str, char * xQ_str,
                              char * yQ_str, uint8_t * rnd_buf,
                              uint32_t rnd_buf_len, uint8_t * hash,
                              uint32_t hlen, char * r_str, char * s_str,
                              int result )
{
    mbedtls_ecp_group grp;
    mbedtls_ecp_point Q;
    mbedtls_mpi d, r, s, r_check, s_check;
    rnd_buf_info rnd_info;

    mbedtls_ecp_group_init( &grp );
    mbedtls_ecp_point_init( &Q );
    mbedtls_mpi_init( &d ); mbedtls_mpi_init( &r ); mbedtls_mpi_init( &s );
    mbedtls_mpi_init( &r_check ); mbedtls_mpi_init( &s_check );

    TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
    TEST_ASSERT( mbedtls_ecp_point_read_string( &Q, 16, xQ_str, yQ_str ) == 0 );
    TEST_ASSERT( mbedtls_mpi_read_string( &d, 16, d_str ) == 0 );
    TEST_ASSERT( mbedtls_mpi_read_string( &r_check, 16, r_str ) == 0 );
    TEST_ASSERT( mbedtls_mpi_read_string( &s_check, 16, s_str ) == 0 );
    rnd_info.buf = rnd_buf;
    rnd_info.length = rnd_buf_len;

    /* Fix rnd_buf by shifting it left if necessary */
    if( grp.nbits % 8 != 0 )
    {
        unsigned char shift = 8 - ( grp.nbits % 8 );
        size_t i;

        for( i = 0; i < rnd_info.length - 1; i++ )
            rnd_buf[i] = rnd_buf[i] << shift | rnd_buf[i+1] >> ( 8 - shift );

        rnd_buf[rnd_info.length-1] <<= shift;
    }

    TEST_ASSERT( mbedtls_ecdsa_sign( &grp, &r, &s, &d, hash, hlen,
                 rnd_buffer_rand, &rnd_info ) == result );

    if ( result == 0)
    {
        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &r, &r_check ) == 0 );
        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &s, &s_check ) == 0 );

        TEST_ASSERT( mbedtls_ecdsa_verify( &grp, hash, hlen, &Q, &r_check, &s_check ) == 0 );
    }

exit:
    mbedtls_ecp_group_free( &grp );
    mbedtls_ecp_point_free( &Q );
    mbedtls_mpi_free( &d ); mbedtls_mpi_free( &r ); mbedtls_mpi_free( &s );
    mbedtls_mpi_free( &r_check ); mbedtls_mpi_free( &s_check );
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_ECDSA_DETERMINISTIC */
void ecdsa_det_test_vectors( int id, char * d_str, int md_alg, char * msg,
                             char * r_str, char * s_str )
{
    mbedtls_ecp_group grp;
    mbedtls_mpi d, r, s, r_check, s_check;
    unsigned char hash[MBEDTLS_MD_MAX_SIZE];
    size_t hlen;
    const mbedtls_md_info_t *md_info;

    mbedtls_ecp_group_init( &grp );
    mbedtls_mpi_init( &d ); mbedtls_mpi_init( &r ); mbedtls_mpi_init( &s );
    mbedtls_mpi_init( &r_check ); mbedtls_mpi_init( &s_check );
    memset( hash, 0, sizeof( hash ) );

    TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
    TEST_ASSERT( mbedtls_mpi_read_string( &d, 16, d_str ) == 0 );
    TEST_ASSERT( mbedtls_mpi_read_string( &r_check, 16, r_str ) == 0 );
    TEST_ASSERT( mbedtls_mpi_read_string( &s_check, 16, s_str ) == 0 );

    md_info = mbedtls_md_info_from_type( md_alg );
    TEST_ASSERT( md_info != NULL );
    hlen = mbedtls_md_get_size( md_info );
    mbedtls_md( md_info, (const unsigned char *) msg, strlen( msg ), hash );

    TEST_ASSERT( mbedtls_ecdsa_sign_det( &grp, &r, &s, &d, hash, hlen, md_alg ) == 0 );

    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &r, &r_check ) == 0 );
    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &s, &s_check ) == 0 );

exit:
    mbedtls_ecp_group_free( &grp );
    mbedtls_mpi_free( &d ); mbedtls_mpi_free( &r ); mbedtls_mpi_free( &s );
    mbedtls_mpi_free( &r_check ); mbedtls_mpi_free( &s_check );
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_SHA256_C */
void ecdsa_write_read_random( int id )
{
    mbedtls_ecdsa_context ctx;
    rnd_pseudo_info rnd_info;
    unsigned char hash[32];
    unsigned char sig[200];
    size_t sig_len, i;

    mbedtls_ecdsa_init( &ctx );
    memset( &rnd_info, 0x00, sizeof( rnd_pseudo_info ) );
    memset( hash, 0, sizeof( hash ) );
    memset( sig, 0x2a, sizeof( sig ) );

    /* prepare material for signature */
    TEST_ASSERT( rnd_pseudo_rand( &rnd_info, hash, sizeof( hash ) ) == 0 );

    /* generate signing key */
    TEST_ASSERT( mbedtls_ecdsa_genkey( &ctx, id, &rnd_pseudo_rand, &rnd_info ) == 0 );

    /* generate and write signature, then read and verify it */
    TEST_ASSERT( mbedtls_ecdsa_write_signature( &ctx, MBEDTLS_MD_SHA256,
                 hash, sizeof( hash ),
                 sig, &sig_len, &rnd_pseudo_rand, &rnd_info ) == 0 );
    TEST_ASSERT( mbedtls_ecdsa_read_signature( &ctx, hash, sizeof( hash ),
                 sig, sig_len ) == 0 );

    /* check we didn't write past the announced length */
    for( i = sig_len; i < sizeof( sig ); i++ )
        TEST_ASSERT( sig[i] == 0x2a );

    /* try verification with invalid length */
    TEST_ASSERT( mbedtls_ecdsa_read_signature( &ctx, hash, sizeof( hash ),
                 sig, sig_len - 1 ) != 0 );
    TEST_ASSERT( mbedtls_ecdsa_read_signature( &ctx, hash, sizeof( hash ),
                 sig, sig_len + 1 ) != 0 );

    /* try invalid sequence tag */
    sig[0]++;
    TEST_ASSERT( mbedtls_ecdsa_read_signature( &ctx, hash, sizeof( hash ),
                 sig, sig_len ) != 0 );
    sig[0]--;

    /* try modifying r */
    sig[10]++;
    TEST_ASSERT( mbedtls_ecdsa_read_signature( &ctx, hash, sizeof( hash ),
                 sig, sig_len ) != 0 );
    sig[10]--;

    /* try modifying s */
    sig[sig_len - 1]++;
    TEST_ASSERT( mbedtls_ecdsa_read_signature( &ctx, hash, sizeof( hash ),
                 sig, sig_len ) != 0 );
    sig[sig_len - 1]--;

exit:
    mbedtls_ecdsa_free( &ctx );
}
/* END_CASE */