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Document aeios.AES.rekey() and refactor arg validation

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This commit is contained in:
Isaac Benitez 2023-03-05 12:58:40 -08:00
parent 763d7e4c5b
commit 90155925d5
1 changed files with 28 additions and 12 deletions
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40
shared-bindings/aesio/aes.c
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@ -98,33 +98,49 @@ STATIC mp_obj_t aesio_aes_make_new(const mp_obj_type_t *type, size_t n_args,
return MP_OBJ_FROM_PTR(self);
}
STATIC mp_obj_t aesio_aes_rekey(size_t n_args, const mp_obj_t *pos_args) {
//| def rekey(
//| self,
//| key: ReadableBuffer,
//| iv: Optional[ReadableBuffer] = None,
//| ) -> None:
//| """Update the AES state with the given key.
//|
//| :param ~circuitpython_typing.ReadableBuffer key: A 16-, 24-, or 32-byte key
//| :param ~circuitpython_typing.ReadableBuffer iv: Initialization vector to use
//| for CBC or CTR mode"""
//| ...
STATIC mp_obj_t aesio_aes_rekey(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
aesio_aes_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
enum { ARG_key, ARG_IV };
static const mp_arg_t allowed_args[] = {
{MP_QSTR_key, MP_ARG_OBJ | MP_ARG_REQUIRED, {.u_obj = MP_OBJ_NULL} },
{MP_QSTR_IV, MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(pos_args[1], &bufinfo, MP_BUFFER_READ);
mp_get_buffer_raise(args[ARG_key].u_obj, &bufinfo, MP_BUFFER_READ);
const uint8_t *key = bufinfo.buf;
size_t key_length = bufinfo.len;
if (key == NULL) {
mp_raise_ValueError(translate("No key was specified"));
}
if ((key_length != 16) && (key_length != 24) && (key_length != 32)) {
mp_raise_ValueError(translate("Key must be 16, 24, or 32 bytes long"));
}
const uint8_t *iv = NULL;
if (n_args > 2) {
mp_get_buffer_raise(pos_args[2], &bufinfo, MP_BUFFER_READ);
size_t iv_length = bufinfo.len;
iv = (const uint8_t *)bufinfo.buf;
(void)mp_arg_validate_length(iv_length, AES_BLOCKLEN, MP_QSTR_IV);
if (args[ARG_IV].u_obj != NULL &&
mp_get_buffer(args[ARG_IV].u_obj, &bufinfo, MP_BUFFER_READ)) {
(void)mp_arg_validate_length(bufinfo.len, AES_BLOCKLEN, MP_QSTR_IV);
iv = bufinfo.buf;
}
common_hal_aesio_aes_rekey(self, key, key_length, iv);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_VAR(aesio_aes_rekey_obj, 2, aesio_aes_rekey);
MP_DEFINE_CONST_FUN_OBJ_KW(aesio_aes_rekey_obj, 1, aesio_aes_rekey);
STATIC void validate_length(aesio_aes_obj_t *self, size_t src_length,
size_t dest_length) {