int mbedtls_ecies_write_hmac(unsigned char **p, unsigned char *start,
mbedtls_md_type_t hmac_type, const unsigned char *hmac, size_t hmac_len)
{
int result = 0;
size_t len = 0;
size_t par_len = 0;
const char *oid = NULL;
size_t oid_len = 0;
if (hmac_type == MBEDTLS_MD_NONE || hmac == NULL || hmac_len == 0)
{
return MBEDTLS_ERR_ECIES_BAD_INPUT_DATA;
}
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_octet_string(p, start, hmac, hmac_len)
);
ACCUMULATE_AND_CHECK(result, par_len,
mbedtls_asn1_write_null(p, start)
);
INVOKE_AND_CHECK(result,
mbedtls_oid_get_oid_by_md(hmac_type, &oid, &oid_len)
);
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_algorithm_identifier(p, start, oid, oid_len, par_len)
);
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_len(p, start, len)
);
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)
);
return (int)len;
}
int mbedtls_ecies_write_kdf(unsigned char **p, unsigned char *start,
mbedtls_kdf_type_t kdf_type, mbedtls_md_type_t md_type)
{
int result = 0;
int len = 0;
size_t md_par_len = 0;
size_t kdf_par_len = 0;
const char *oid = NULL;
size_t oid_len = 0;
if (kdf_type == MBEDTLS_KDF_NONE || md_type == MBEDTLS_MD_NONE)
{
return MBEDTLS_ERR_ECIES_BAD_INPUT_DATA;
}
ACCUMULATE_AND_CHECK(result, md_par_len,
mbedtls_asn1_write_null(p, start)
);
INVOKE_AND_CHECK(result,
mbedtls_oid_get_oid_by_md(md_type, &oid, &oid_len)
);
ACCUMULATE_AND_CHECK(result, kdf_par_len,
mbedtls_asn1_write_algorithm_identifier(p, start, oid, oid_len, md_par_len)
);
INVOKE_AND_CHECK(result,
mbedtls_oid_get_oid_by_kdf_alg(kdf_type, &oid, &oid_len)
);
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_algorithm_identifier(p, start, oid, oid_len, kdf_par_len)
);
return (int)len;
}
int mbedtls_asn1_write_algorithm_identifier( unsigned char **p, unsigned char *start,
const char *oid, size_t oid_len,
size_t par_len )
{
int ret;
size_t len = 0;
if( par_len == 0 )
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_null( p, start ) );
else
len += par_len;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid, oid_len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
return( (int) len );
}
