/* BEGIN_HEADER */
#include <polarssl/hmac_drbg.h>

typedef struct
{
    unsigned char *p;
    size_t len;
} entropy_ctx;

int entropy_func( void *data, unsigned char *buf, size_t len )
{
    entropy_ctx *ctx = (entropy_ctx *) data;

    if( len > ctx->len )
        return( -1 );

    memcpy( buf, ctx->p, len );

    ctx->p += len;
    ctx->len -= len;

    return( 0 );
}
/* END_HEADER */

/* BEGIN_DEPENDENCIES
 * depends_on:POLARSSL_HMAC_DRBG_C
 * END_DEPENDENCIES
 */

/* BEGIN_CASE depends_on:POLARSSL_FS_IO */
void hmac_drbg_seed_file( int md_alg, char *path, int ret )
{
    const md_info_t *md_info;
    hmac_drbg_context ctx;

    TEST_ASSERT( ( md_info = md_info_from_type( md_alg ) ) != NULL );
    TEST_ASSERT( hmac_drbg_init( &ctx, md_info, rnd_std_rand, NULL,
                                 NULL, 0 ) == 0 );

    TEST_ASSERT( hmac_drbg_write_seed_file( &ctx, path ) == ret );
    TEST_ASSERT( hmac_drbg_update_seed_file( &ctx, path ) == ret );

    hmac_drbg_free( &ctx );
}
/* END_CASE */

/* BEGIN_CASE */
void hmac_drbg_no_reseed( int md_alg,
                          char *entropy_hex, char *custom_hex,
                          char *add1_hex, char *add2_hex,
                          char *output_hex )
{
    unsigned char entropy[512];
    unsigned char custom[512];
    unsigned char add1[512];
    unsigned char add2[512];
    unsigned char output[512];
    unsigned char my_output[512];
    size_t custom_len, add1_len, add2_len, out_len;
    entropy_ctx p_entropy;
    const md_info_t *md_info;
    hmac_drbg_context ctx;

    memset( my_output, 0, sizeof my_output );

    custom_len = unhexify( custom, custom_hex );
    add1_len = unhexify( add1, add1_hex );
    add2_len = unhexify( add2, add2_hex );
    out_len = unhexify( output, output_hex );
    p_entropy.len = unhexify( entropy, entropy_hex );
    p_entropy.p = entropy;

    TEST_ASSERT( ( md_info = md_info_from_type( md_alg ) ) != NULL );
    TEST_ASSERT( hmac_drbg_init( &ctx, md_info, entropy_func, &p_entropy,
                                 custom, custom_len ) == 0 );
    TEST_ASSERT( hmac_drbg_random_with_add( &ctx, my_output, out_len,
                                            add1, add1_len ) == 0 );
    TEST_ASSERT( hmac_drbg_random_with_add( &ctx, my_output, out_len,
                                            add2, add2_len ) == 0 );
    hmac_drbg_free( &ctx );

    /* Check output is correct */
    TEST_ASSERT( memcmp( my_output, output, out_len ) == 0 );

    /* Check we didn't write more bytes than needed */
    TEST_ASSERT( my_output[out_len + 0] == 0 );
    TEST_ASSERT( my_output[out_len + 1] == 0 );
    TEST_ASSERT( my_output[out_len + 2] == 0 );
    TEST_ASSERT( my_output[out_len + 3] == 0 );
}
/* END_CASE */