/*

 * Copyright (c) 2020-2022 Yubico AB. All rights reserved.

 * Use of this source code is governed by a BSD-style

 * license that can be found in the LICENSE file.

 * SPDX-License-Identifier: BSD-2-Clause

 */

#include "fido.h"

#include "fido/config.h"

#include "fido/es256.h"

#define CMD_ENABLE_ENTATTEST    0x01

#define CMD_TOGGLE_ALWAYS_UV    0x02

#define CMD_SET_PIN_MINLEN      0x03

static int

config_prepare_hmac(uint8_t subcmd, const cbor_item_t *item, fido_blob_t *hmac)

{

        uint8_t prefix[32 + 2 * sizeof(uint8_t)], cbor[128];

        size_t cbor_len = 0;

        memset(prefix, 0xff, sizeof(prefix));

        prefix[sizeof(prefix) - 2] = CTAP_CBOR_CONFIG;

        prefix[sizeof(prefix) - 1] = subcmd;

        if (item != NULL) {

                if ((cbor_len = cbor_serialize(item, cbor, sizeof(cbor))) == 0) {

                        fido_log_debug("%s: cbor_serialize", __func__);

                        return -1;

                }

        }

        if ((hmac->ptr = malloc(cbor_len + sizeof(prefix))) == NULL) {

                fido_log_debug("%s: malloc", __func__);

                return -1;

        }

        memcpy(hmac->ptr, prefix, sizeof(prefix));

        memcpy(hmac->ptr + sizeof(prefix), cbor, cbor_len);

        hmac->len = cbor_len + sizeof(prefix);

        return 0;

}

static int

config_tx(fido_dev_t *dev, uint8_t subcmd, cbor_item_t **paramv, size_t paramc,

    const char *pin, int *ms)

{

        cbor_item_t *argv[4];

        es256_pk_t *pk = NULL;

        fido_blob_t *ecdh = NULL, f, hmac;

        const uint8_t cmd = CTAP_CBOR_CONFIG;

        int r = FIDO_ERR_INTERNAL;

        memset(&f, 0, sizeof(f));

        memset(&hmac, 0, sizeof(hmac));

        memset(&argv, 0, sizeof(argv));

        /* subCommand */

        if ((argv[0] = cbor_build_uint8(subcmd)) == NULL) {

                fido_log_debug("%s: cbor encode", __func__);

                goto fail;

        }

        /* subCommandParams */

        if (paramc != 0 &&

            (argv[1] = cbor_flatten_vector(paramv, paramc)) == NULL) {

                fido_log_debug("%s: cbor_flatten_vector", __func__);

                goto fail;

        }

        /* pinProtocol, pinAuth */

        if (pin != NULL ||

            (fido_dev_supports_permissions(dev) && fido_dev_has_uv(dev))) {

                if (config_prepare_hmac(subcmd, argv[1], &hmac) < 0) {

                        fido_log_debug("%s: config_prepare_hmac", __func__);

                        goto fail;

                }

                if ((r = fido_do_ecdh(dev, &pk, &ecdh, ms)) != FIDO_OK) {

                        fido_log_debug("%s: fido_do_ecdh", __func__);

                        goto fail;

                }

                if ((r = cbor_add_uv_params(dev, cmd, &hmac, pk, ecdh, pin,

                    NULL, &argv[3], &argv[2], ms)) != FIDO_OK) {

                        fido_log_debug("%s: cbor_add_uv_params", __func__);

                        goto fail;

                }

        }

        /* framing and transmission */

        if (cbor_build_frame(cmd, argv, nitems(argv), &f) < 0 ||

            fido_tx(dev, CTAP_CMD_CBOR, f.ptr, f.len, ms) < 0) {

                fido_log_debug("%s: fido_tx", __func__);

                r = FIDO_ERR_TX;

                goto fail;

        }

        r = FIDO_OK;

fail:

        cbor_vector_free(argv, nitems(argv));

        es256_pk_free(&pk);

        fido_blob_free(&ecdh);

        free(f.ptr);

        free(hmac.ptr);

        return r;

}

static int

config_enable_entattest_wait(fido_dev_t *dev, const char *pin, int *ms)

{

        int r;

        if ((r = config_tx(dev, CMD_ENABLE_ENTATTEST, NULL, 0, pin,

            ms)) != FIDO_OK)

                return r;

        return fido_rx_cbor_status(dev, ms);

}

int

fido_dev_enable_entattest(fido_dev_t *dev, const char *pin)

{

        int ms = dev->timeout_ms;

        return (config_enable_entattest_wait(dev, pin, &ms));

}

static int

config_toggle_always_uv_wait(fido_dev_t *dev, const char *pin, int *ms)

{

        int r;

        if ((r = config_tx(dev, CMD_TOGGLE_ALWAYS_UV, NULL, 0, pin,

            ms)) != FIDO_OK)

                return r;

        return (fido_rx_cbor_status(dev, ms));

}

int

fido_dev_toggle_always_uv(fido_dev_t *dev, const char *pin)

{

        int ms = dev->timeout_ms;

        return config_toggle_always_uv_wait(dev, pin, &ms);

}

static int

config_pin_minlen_tx(fido_dev_t *dev, size_t len, bool force,

    const fido_str_array_t *rpid, const char *pin, int *ms)

{

        cbor_item_t *argv[3];

        int r;

        memset(argv, 0, sizeof(argv));

        if ((rpid == NULL && len == 0 && !force) || len > UINT8_MAX) {

                r = FIDO_ERR_INVALID_ARGUMENT;

                goto fail;

        }

        if (len && (argv[0] = cbor_build_uint8((uint8_t)len)) == NULL) {

                fido_log_debug("%s: cbor_encode_uint8", __func__);

                r = FIDO_ERR_INTERNAL;

                goto fail;

        }

        if (rpid != NULL && (argv[1] = cbor_encode_str_array(rpid)) == NULL) {

                fido_log_debug("%s: cbor_encode_str_array", __func__);

                r = FIDO_ERR_INTERNAL;

                goto fail;

        }

        if (force && (argv[2] = cbor_build_bool(true)) == NULL) {

                fido_log_debug("%s: cbor_build_bool", __func__);

                r = FIDO_ERR_INTERNAL;

                goto fail;

        }

        if ((r = config_tx(dev, CMD_SET_PIN_MINLEN, argv, nitems(argv),

            pin, ms)) != FIDO_OK) {

                fido_log_debug("%s: config_tx", __func__);

                goto fail;

        }

fail:

        cbor_vector_free(argv, nitems(argv));

        return r;

}

static int

config_pin_minlen(fido_dev_t *dev, size_t len, bool force,

    const fido_str_array_t *rpid, const char *pin, int *ms)

{

        int r;

        if ((r = config_pin_minlen_tx(dev, len, force, rpid, pin,

            ms)) != FIDO_OK)

                return r;

        return fido_rx_cbor_status(dev, ms);

}

int

fido_dev_set_pin_minlen(fido_dev_t *dev, size_t len, const char *pin)

{

        int ms = dev->timeout_ms;

        return config_pin_minlen(dev, len, false, NULL, pin, &ms);

}

int

fido_dev_force_pin_change(fido_dev_t *dev, const char *pin)

{

        int ms = dev->timeout_ms;

        return config_pin_minlen(dev, 0, true, NULL, pin, &ms);

}

int

fido_dev_set_pin_minlen_rpid(fido_dev_t *dev, const char * const *rpid,

    size_t n, const char *pin)

{

        fido_str_array_t sa;

        int ms = dev->timeout_ms;

        int r;

        memset(&sa, 0, sizeof(sa));

        if (fido_str_array_pack(&sa, rpid, n) < 0) {

                fido_log_debug("%s: fido_str_array_pack", __func__);

                r = FIDO_ERR_INTERNAL;

                goto fail;

        }

        r = config_pin_minlen(dev, 0, false, &sa, pin, &ms);

fail:

        fido_str_array_free(&sa);

        return r;

}