/* BEGIN_HEADER */
#include "mbedtls/hkdf.h"
#include "mbedtls/md_internal.h"
/* END_HEADER */

/* BEGIN_DEPENDENCIES
 * depends_on:MBEDTLS_HKDF_C
 * END_DEPENDENCIES
 */

/* BEGIN_CASE */
void test_hkdf( int md_alg, char *hex_ikm_string, char *hex_salt_string,
                char *hex_info_string, char *hex_okm_string )
{
    int ret;
    size_t ikm_len, salt_len, info_len, okm_len;
    unsigned char ikm[128] = { '\0' };
    unsigned char salt[128] = { '\0' };
    unsigned char info[128] = { '\0' };
    unsigned char expected_okm[128] = { '\0' };
    unsigned char okm[128] = { '\0' };
    /*
     * okm_hex is the string representation of okm,
     * so its size is twice the size of okm, and an extra null-termination.
     */
    unsigned char okm_hex[257] = { '\0' };

    const mbedtls_md_info_t *md = mbedtls_md_info_from_type( md_alg );
    TEST_ASSERT( md != NULL );

    ikm_len = mbedtls_test_unhexify( ikm, hex_ikm_string );
    salt_len = mbedtls_test_unhexify( salt, hex_salt_string );
    info_len = mbedtls_test_unhexify( info, hex_info_string );
    okm_len = mbedtls_test_unhexify( expected_okm, hex_okm_string );

    ret = mbedtls_hkdf( md, salt, salt_len, ikm, ikm_len, info, info_len, okm,
                        okm_len);
    TEST_ASSERT( ret == 0 );

    // Run mbedtls_test_hexify on it so that it looks nicer if the assertion fails
    mbedtls_test_hexify( okm_hex, okm, okm_len );
    TEST_ASSERT( !strcmp( (char *)okm_hex, hex_okm_string ) );
}
/* END_CASE */

/* BEGIN_CASE */
void test_hkdf_extract( int md_alg, char *hex_ikm_string,
                        char *hex_salt_string, char *hex_prk_string )
{
    int ret;
    unsigned char *ikm = NULL;
    unsigned char *salt = NULL;
    unsigned char *prk = NULL;
    unsigned char *output_prk = NULL;
    size_t ikm_len, salt_len, prk_len, output_prk_len;

    const mbedtls_md_info_t *md = mbedtls_md_info_from_type( md_alg );
    TEST_ASSERT( md != NULL );

    output_prk_len = mbedtls_md_get_size( md );
    output_prk = mbedtls_calloc( 1, output_prk_len );

    ikm = unhexify_alloc( hex_ikm_string, &ikm_len );
    salt = unhexify_alloc( hex_salt_string, &salt_len );
    prk = unhexify_alloc( hex_prk_string, &prk_len );
    TEST_ASSERT( prk_len == output_prk_len );

    ret = mbedtls_hkdf_extract( md, salt, salt_len, ikm, ikm_len, output_prk );
    TEST_ASSERT( ret == 0 );

    TEST_ASSERT( !memcmp( output_prk, prk, prk_len ) );

exit:
    mbedtls_free(ikm);
    mbedtls_free(salt);
    mbedtls_free(prk);
    mbedtls_free(output_prk);
}
/* END_CASE */

/* BEGIN_CASE */
void test_hkdf_expand( int md_alg, char *hex_info_string,
                       char *hex_prk_string, char *hex_okm_string )
{
    enum { OKM_LEN  = 1024 };
    int ret;
    unsigned char *info = NULL;
    unsigned char *prk = NULL;
    unsigned char *okm = NULL;
    unsigned char *output_okm = NULL;
    size_t info_len, prk_len, okm_len;

    const mbedtls_md_info_t *md = mbedtls_md_info_from_type( md_alg );
    TEST_ASSERT( md != NULL );

    output_okm = mbedtls_calloc( OKM_LEN, 1 );

    prk = unhexify_alloc( hex_prk_string, &prk_len );
    info = unhexify_alloc( hex_info_string, &info_len );
    okm = unhexify_alloc( hex_okm_string, &okm_len );
    TEST_ASSERT( prk_len == mbedtls_md_get_size( md ) );
    TEST_ASSERT( okm_len < OKM_LEN );

    ret = mbedtls_hkdf_expand( md, prk, prk_len, info, info_len,
                               output_okm, OKM_LEN );
    TEST_ASSERT( ret == 0 );
    TEST_ASSERT( !memcmp( output_okm, okm, okm_len ) );

exit:
    mbedtls_free(info);
    mbedtls_free(prk);
    mbedtls_free(okm);
    mbedtls_free(output_okm);
}
/* END_CASE */

/* BEGIN_CASE */
void test_hkdf_extract_ret( int hash_len, int ret )
{
    int output_ret;
    unsigned char *salt = NULL;
    unsigned char *ikm = NULL;
    unsigned char *prk = NULL;
    size_t salt_len, ikm_len;
    struct mbedtls_md_info_t fake_md_info;

    memset( &fake_md_info, 0, sizeof( fake_md_info ) );
    fake_md_info.type = MBEDTLS_MD_NONE;
    fake_md_info.size = hash_len;

    prk = mbedtls_calloc( MBEDTLS_MD_MAX_SIZE, 1 );
    salt_len = 0;
    ikm_len = 0;

    output_ret = mbedtls_hkdf_extract( &fake_md_info, salt, salt_len,
                                       ikm, ikm_len, prk );
    TEST_ASSERT( output_ret == ret );

exit:
    mbedtls_free(prk);
}
/* END_CASE */

/* BEGIN_CASE */
void test_hkdf_expand_ret( int hash_len, int prk_len, int okm_len, int ret )
{
    int output_ret;
    unsigned char *info = NULL;
    unsigned char *prk = NULL;
    unsigned char *okm = NULL;
    size_t info_len;
    struct mbedtls_md_info_t fake_md_info;

    memset( &fake_md_info, 0, sizeof( fake_md_info ) );
    fake_md_info.type = MBEDTLS_MD_NONE;
    fake_md_info.size = hash_len;

    info_len = 0;

    if (prk_len > 0)
        prk = mbedtls_calloc( prk_len, 1 );

    if (okm_len > 0)
        okm = mbedtls_calloc( okm_len, 1 );

    output_ret = mbedtls_hkdf_expand( &fake_md_info, prk, prk_len,
                                      info, info_len, okm, okm_len );
    TEST_ASSERT( output_ret == ret );

exit:
    mbedtls_free(prk);
    mbedtls_free(okm);
}
/* END_CASE */