/*
 * Copyright (c) 2018-2022 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.
 */

#include "fido.h"

#ifndef TLS
#define TLS
#endif

static TLS bool disable_u2f_fallback;

#ifdef FIDO_FUZZ
static void
set_random_report_len(fido_dev_t *dev)
{
        dev->rx_len = CTAP_MIN_REPORT_LEN +
            uniform_random(CTAP_MAX_REPORT_LEN - CTAP_MIN_REPORT_LEN + 1);
        dev->tx_len = CTAP_MIN_REPORT_LEN +
            uniform_random(CTAP_MAX_REPORT_LEN - CTAP_MIN_REPORT_LEN + 1);
}
#endif

static void
fido_dev_set_extension_flags(fido_dev_t *dev, const fido_cbor_info_t *info)
{
        char * const    *ptr = fido_cbor_info_extensions_ptr(info);
        size_t           len = fido_cbor_info_extensions_len(info);

        for (size_t i = 0; i < len; i++)
                if (strcmp(ptr[i], "credProtect") == 0)
                        dev->flags |= FIDO_DEV_CRED_PROT;
}

static void
fido_dev_set_option_flags(fido_dev_t *dev, const fido_cbor_info_t *info)
{
        char * const    *ptr = fido_cbor_info_options_name_ptr(info);
        const bool      *val = fido_cbor_info_options_value_ptr(info);
        size_t           len = fido_cbor_info_options_len(info);

        for (size_t i = 0; i < len; i++)
                if (strcmp(ptr[i], "clientPin") == 0) {
                        dev->flags |= val[i] ?
                            FIDO_DEV_PIN_SET : FIDO_DEV_PIN_UNSET;
                } else if (strcmp(ptr[i], "credMgmt") == 0 ||
                           strcmp(ptr[i], "credentialMgmtPreview") == 0) {
                        if (val[i])
                                dev->flags |= FIDO_DEV_CREDMAN;
                } else if (strcmp(ptr[i], "uv") == 0) {
                        dev->flags |= val[i] ?
                            FIDO_DEV_UV_SET : FIDO_DEV_UV_UNSET;
                } else if (strcmp(ptr[i], "pinUvAuthToken") == 0) {
                        if (val[i])
                                dev->flags |= FIDO_DEV_TOKEN_PERMS;
                }
}

static void
fido_dev_set_protocol_flags(fido_dev_t *dev, const fido_cbor_info_t *info)
{
        const uint8_t   *ptr = fido_cbor_info_protocols_ptr(info);
        size_t           len = fido_cbor_info_protocols_len(info);

        for (size_t i = 0; i < len; i++)
                switch (ptr[i]) {
                case CTAP_PIN_PROTOCOL1:
                        dev->flags |= FIDO_DEV_PIN_PROTOCOL1;
                        break;
                case CTAP_PIN_PROTOCOL2:
                        dev->flags |= FIDO_DEV_PIN_PROTOCOL2;
                        break;
                default:
                        fido_log_debug("%s: unknown protocol %u", __func__,
                            ptr[i]);
                        break;
                }
}

static void
fido_dev_set_flags(fido_dev_t *dev, const fido_cbor_info_t *info)
{
        fido_dev_set_extension_flags(dev, info);
        fido_dev_set_option_flags(dev, info);
        fido_dev_set_protocol_flags(dev, info);
}

static int
fido_dev_open_tx(fido_dev_t *dev, const char *path, int *ms)
{
        int r;

        if (dev->io_handle != NULL) {
                fido_log_debug("%s: handle=%p", __func__, dev->io_handle);
                return (FIDO_ERR_INVALID_ARGUMENT);
        }

        if (dev->io.open == NULL || dev->io.close == NULL) {
                fido_log_debug("%s: NULL open/close", __func__);
                return (FIDO_ERR_INVALID_ARGUMENT);
        }

        if (dev->cid != CTAP_CID_BROADCAST) {
                fido_log_debug("%s: cid=0x%x", __func__, dev->cid);
                return (FIDO_ERR_INVALID_ARGUMENT);
        }

        if (fido_get_random(&dev->nonce, sizeof(dev->nonce)) < 0) {
                fido_log_debug("%s: fido_get_random", __func__);
                return (FIDO_ERR_INTERNAL);
        }

        if ((dev->io_handle = dev->io.open(path)) == NULL) {
                fido_log_debug("%s: dev->io.open", __func__);
                return (FIDO_ERR_INTERNAL);
        }

        if (dev->io_own) {
                dev->rx_len = CTAP_MAX_REPORT_LEN;
                dev->tx_len = CTAP_MAX_REPORT_LEN;
        } else {
                dev->rx_len = fido_hid_report_in_len(dev->io_handle);
                dev->tx_len = fido_hid_report_out_len(dev->io_handle);
        }

#ifdef FIDO_FUZZ
        set_random_report_len(dev);
#endif

        if (dev->rx_len < CTAP_MIN_REPORT_LEN ||
            dev->rx_len > CTAP_MAX_REPORT_LEN) {
                fido_log_debug("%s: invalid rx_len %zu", __func__, dev->rx_len);
                r = FIDO_ERR_RX;
                goto fail;
        }

        if (dev->tx_len < CTAP_MIN_REPORT_LEN ||
            dev->tx_len > CTAP_MAX_REPORT_LEN) {
                fido_log_debug("%s: invalid tx_len %zu", __func__, dev->tx_len);
                r = FIDO_ERR_TX;
                goto fail;
        }

        if (fido_tx(dev, CTAP_CMD_INIT, &dev->nonce, sizeof(dev->nonce),
            ms) < 0) {
                fido_log_debug("%s: fido_tx", __func__);
                r = FIDO_ERR_TX;
                goto fail;
        }

        return (FIDO_OK);
fail:
        dev->io.close(dev->io_handle);
        dev->io_handle = NULL;

        return (r);
}

static int
fido_dev_open_rx(fido_dev_t *dev, int *ms)
{
        fido_cbor_info_t        *info = NULL;
        int                      reply_len;
        int                      r;

        if ((reply_len = fido_rx(dev, CTAP_CMD_INIT, &dev->attr,
            sizeof(dev->attr), ms)) < 0) {
                fido_log_debug("%s: fido_rx", __func__);
                r = FIDO_ERR_RX;
                goto fail;
        }

#ifdef FIDO_FUZZ
        dev->attr.nonce = dev->nonce;
#endif

        if ((size_t)reply_len != sizeof(dev->attr) ||
            dev->attr.nonce != dev->nonce) {
                fido_log_debug("%s: invalid nonce", __func__);
                r = FIDO_ERR_RX;
                goto fail;
        }

        dev->flags = 0;
        dev->cid = dev->attr.cid;

        if (fido_dev_is_fido2(dev)) {
                if ((info = fido_cbor_info_new()) == NULL) {
                        fido_log_debug("%s: fido_cbor_info_new", __func__);
                        r = FIDO_ERR_INTERNAL;
                        goto fail;
                }
                if ((r = fido_dev_get_cbor_info_wait(dev, info,
                    ms)) != FIDO_OK) {
                        fido_log_debug("%s: fido_dev_cbor_info_wait: %d",
                            __func__, r);
                        if (disable_u2f_fallback)
                                goto fail;
                        fido_log_debug("%s: falling back to u2f", __func__);
                        fido_dev_force_u2f(dev);
                } else {
                        fido_dev_set_flags(dev, info);
                }
        }

        if (fido_dev_is_fido2(dev) && info != NULL) {
                dev->maxmsgsize = fido_cbor_info_maxmsgsiz(info);
                fido_log_debug("%s: FIDO_MAXMSG=%d, maxmsgsiz=%lu", __func__,
                    FIDO_MAXMSG, (unsigned long)dev->maxmsgsize);
        }

        r = FIDO_OK;
fail:
        fido_cbor_info_free(&info);

        if (r != FIDO_OK) {
                dev->io.close(dev->io_handle);
                dev->io_handle = NULL;
        }

        return (r);
}

static int
fido_dev_open_wait(fido_dev_t *dev, const char *path, int *ms)
{
        int r;

#ifdef USE_WINHELLO
        if (strcmp(path, FIDO_WINHELLO_PATH) == 0)
                return (fido_winhello_open(dev));
#endif
        if ((r = fido_dev_open_tx(dev, path, ms)) != FIDO_OK ||
            (r = fido_dev_open_rx(dev, ms)) != FIDO_OK)
                return (r);

        return (FIDO_OK);
}

static void
run_manifest(fido_dev_info_t *devlist, size_t ilen, size_t *olen,
    const char *type, int (*manifest)(fido_dev_info_t *, size_t, size_t *))
{
        size_t ndevs = 0;
        int r;

        if (*olen >= ilen) {
                fido_log_debug("%s: skipping %s", __func__, type);
                return;
        }
        if ((r = manifest(devlist + *olen, ilen - *olen, &ndevs)) != FIDO_OK)
                fido_log_debug("%s: %s: 0x%x", __func__, type, r);
        fido_log_debug("%s: found %zu %s device%s", __func__, ndevs, type,
            ndevs == 1 ? "" : "s");
        *olen += ndevs;
}

int
fido_dev_info_manifest(fido_dev_info_t *devlist, size_t ilen, size_t *olen)
{
        *olen = 0;

        run_manifest(devlist, ilen, olen, "hid", fido_hid_manifest);
#ifdef USE_NFC
        run_manifest(devlist, ilen, olen, "nfc", fido_nfc_manifest);
#endif
#ifdef USE_PCSC
        run_manifest(devlist, ilen, olen, "pcsc", fido_pcsc_manifest);
#endif
#ifdef USE_WINHELLO
        run_manifest(devlist, ilen, olen, "winhello", fido_winhello_manifest);
#endif

        return (FIDO_OK);
}

int
fido_dev_open_with_info(fido_dev_t *dev)
{
        int ms = dev->timeout_ms;

        if (dev->path == NULL)
                return (FIDO_ERR_INVALID_ARGUMENT);

        return (fido_dev_open_wait(dev, dev->path, &ms));
}

int
fido_dev_open(fido_dev_t *dev, const char *path)
{
        int ms = dev->timeout_ms;

#ifdef USE_NFC
        if (fido_is_nfc(path) && fido_dev_set_nfc(dev) < 0) {
                fido_log_debug("%s: fido_dev_set_nfc", __func__);
                return FIDO_ERR_INTERNAL;
        }
#endif
#ifdef USE_PCSC
        if (fido_is_pcsc(path) && fido_dev_set_pcsc(dev) < 0) {
                fido_log_debug("%s: fido_dev_set_pcsc", __func__);
                return FIDO_ERR_INTERNAL;
        }
#endif

        return (fido_dev_open_wait(dev, path, &ms));
}

int
fido_dev_close(fido_dev_t *dev)
{
#ifdef USE_WINHELLO
        if (dev->flags & FIDO_DEV_WINHELLO)
                return (fido_winhello_close(dev));
#endif
        if (dev->io_handle == NULL || dev->io.close == NULL)
                return (FIDO_ERR_INVALID_ARGUMENT);

        dev->io.close(dev->io_handle);
        dev->io_handle = NULL;
        dev->cid = CTAP_CID_BROADCAST;

        return (FIDO_OK);
}

int
fido_dev_set_sigmask(fido_dev_t *dev, const fido_sigset_t *sigmask)
{
        if (dev->io_handle == NULL || sigmask == NULL)
                return (FIDO_ERR_INVALID_ARGUMENT);

#ifdef USE_NFC
        if (dev->transport.rx == fido_nfc_rx && dev->io.read == fido_nfc_read)
                return (fido_nfc_set_sigmask(dev->io_handle, sigmask));
#endif
        if (dev->transport.rx == NULL && dev->io.read == fido_hid_read)
                return (fido_hid_set_sigmask(dev->io_handle, sigmask));

        return (FIDO_ERR_INVALID_ARGUMENT);
}

int
fido_dev_cancel(fido_dev_t *dev)
{
        int ms = dev->timeout_ms;

#ifdef USE_WINHELLO
        if (dev->flags & FIDO_DEV_WINHELLO)
                return (fido_winhello_cancel(dev));
#endif
        if (fido_dev_is_fido2(dev) == false)
                return (FIDO_ERR_INVALID_ARGUMENT);
        if (fido_tx(dev, CTAP_CMD_CANCEL, NULL, 0, &ms) < 0)
                return (FIDO_ERR_TX);

        return (FIDO_OK);
}

int
fido_dev_set_io_functions(fido_dev_t *dev, const fido_dev_io_t *io)
{
        if (dev->io_handle != NULL) {
                fido_log_debug("%s: non-NULL handle", __func__);
                return (FIDO_ERR_INVALID_ARGUMENT);
        }

        if (io == NULL || io->open == NULL || io->close == NULL ||
            io->read == NULL || io->write == NULL) {
                fido_log_debug("%s: NULL function", __func__);
                return (FIDO_ERR_INVALID_ARGUMENT);
        }

        dev->io = *io;
        dev->io_own = true;

        return (FIDO_OK);
}

int
fido_dev_set_transport_functions(fido_dev_t *dev, const fido_dev_transport_t *t)
{
        if (dev->io_handle != NULL) {
                fido_log_debug("%s: non-NULL handle", __func__);
                return (FIDO_ERR_INVALID_ARGUMENT);
        }

        dev->transport = *t;
        dev->io_own = true;

        return (FIDO_OK);
}

void *
fido_dev_io_handle(const fido_dev_t *dev)
{

        return (dev->io_handle);
}

void
fido_init(int flags)
{
        if (flags & FIDO_DEBUG || getenv("FIDO_DEBUG") != NULL)
                fido_log_init();

        disable_u2f_fallback = (flags & FIDO_DISABLE_U2F_FALLBACK);
}

fido_dev_t *
fido_dev_new(void)
{
        fido_dev_t *dev;

        if ((dev = calloc(1, sizeof(*dev))) == NULL)
                return (NULL);

        dev->cid = CTAP_CID_BROADCAST;
        dev->timeout_ms = -1;
        dev->io = (fido_dev_io_t) {
                &fido_hid_open,
                &fido_hid_close,
                &fido_hid_read,
                &fido_hid_write,
        };

        return (dev);
}

fido_dev_t *
fido_dev_new_with_info(const fido_dev_info_t *di)
{
        fido_dev_t *dev;

        if ((dev = calloc(1, sizeof(*dev))) == NULL)
                return (NULL);

#if 0
        if (di->io.open == NULL || di->io.close == NULL ||
            di->io.read == NULL || di->io.write == NULL) {
                fido_log_debug("%s: NULL function", __func__);
                fido_dev_free(&dev);
                return (NULL);
        }
#endif

        dev->io = di->io;
        dev->io_own = di->transport.tx != NULL || di->transport.rx != NULL;
        dev->transport = di->transport;
        dev->cid = CTAP_CID_BROADCAST;
        dev->timeout_ms = -1;

        if ((dev->path = strdup(di->path)) == NULL) {
                fido_log_debug("%s: strdup", __func__);
                fido_dev_free(&dev);
                return (NULL);
        }

        return (dev);
}

void
fido_dev_free(fido_dev_t **dev_p)
{
        fido_dev_t *dev;

        if (dev_p == NULL || (dev = *dev_p) == NULL)
                return;

        free(dev->path);
        free(dev);

        *dev_p = NULL;
}

uint8_t
fido_dev_protocol(const fido_dev_t *dev)
{
        return (dev->attr.protocol);
}

uint8_t
fido_dev_major(const fido_dev_t *dev)
{
        return (dev->attr.major);
}

uint8_t
fido_dev_minor(const fido_dev_t *dev)
{
        return (dev->attr.minor);
}

uint8_t
fido_dev_build(const fido_dev_t *dev)
{
        return (dev->attr.build);
}

uint8_t
fido_dev_flags(const fido_dev_t *dev)
{
        return (dev->attr.flags);
}

bool
fido_dev_is_fido2(const fido_dev_t *dev)
{
        return (dev->attr.flags & FIDO_CAP_CBOR);
}

bool
fido_dev_is_winhello(const fido_dev_t *dev)
{
        return (dev->flags & FIDO_DEV_WINHELLO);
}

bool
fido_dev_supports_pin(const fido_dev_t *dev)
{
        return (dev->flags & (FIDO_DEV_PIN_SET|FIDO_DEV_PIN_UNSET));
}

bool
fido_dev_has_pin(const fido_dev_t *dev)
{
        return (dev->flags & FIDO_DEV_PIN_SET);
}

bool
fido_dev_supports_cred_prot(const fido_dev_t *dev)
{
        return (dev->flags & FIDO_DEV_CRED_PROT);
}

bool
fido_dev_supports_credman(const fido_dev_t *dev)
{
        return (dev->flags & FIDO_DEV_CREDMAN);
}

bool
fido_dev_supports_uv(const fido_dev_t *dev)
{
        return (dev->flags & (FIDO_DEV_UV_SET|FIDO_DEV_UV_UNSET));
}

bool
fido_dev_has_uv(const fido_dev_t *dev)
{
        return (dev->flags & FIDO_DEV_UV_SET);
}

bool
fido_dev_supports_permissions(const fido_dev_t *dev)
{
        return (dev->flags & FIDO_DEV_TOKEN_PERMS);
}

void
fido_dev_force_u2f(fido_dev_t *dev)
{
        dev->attr.flags &= (uint8_t)~FIDO_CAP_CBOR;
        dev->flags = 0;
}

void
fido_dev_force_fido2(fido_dev_t *dev)
{
        dev->attr.flags |= FIDO_CAP_CBOR;
}

uint8_t
fido_dev_get_pin_protocol(const fido_dev_t *dev)
{
        if (dev->flags & FIDO_DEV_PIN_PROTOCOL2)
                return (CTAP_PIN_PROTOCOL2);
        else if (dev->flags & FIDO_DEV_PIN_PROTOCOL1)
                return (CTAP_PIN_PROTOCOL1);

        return (0);
}

uint64_t
fido_dev_maxmsgsize(const fido_dev_t *dev)
{
        return (dev->maxmsgsize);
}

int
fido_dev_set_timeout(fido_dev_t *dev, int ms)
{
        if (ms < -1)
                return (FIDO_ERR_INVALID_ARGUMENT);

        dev->timeout_ms = ms;

        return (FIDO_OK);
}