/*
* Copyright (c) 2018 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 <openssl/sha.h>
#include "fido.h"
#ifndef TLS
#define TLS
#endif
typedef struct dev_manifest_func_node {
dev_manifest_func_t manifest_func;
struct dev_manifest_func_node *next;
} dev_manifest_func_node_t;
static TLS dev_manifest_func_node_t *manifest_funcs = NULL;
static TLS bool disable_u2f_fallback;
static void
find_manifest_func_node(dev_manifest_func_t f, dev_manifest_func_node_t **curr,
dev_manifest_func_node_t **prev)
{
*prev = NULL;
*curr = manifest_funcs;
while (*curr != NULL && (*curr)->manifest_func != f) {
*prev = *curr;
*curr = (*curr)->next;
}
}
#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 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)) < 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)) != FIDO_OK ||
(r = fido_dev_open_rx(dev, ms)) != FIDO_OK)
return (r);
return (FIDO_OK);
}
int
fido_dev_register_manifest_func(const dev_manifest_func_t f)
{
dev_manifest_func_node_t *prev, *curr, *n;
find_manifest_func_node(f, &curr, &prev);
if (curr != NULL)
return (FIDO_OK);
if ((n = calloc(1, sizeof(*n))) == NULL) {
fido_log_debug("%s: calloc", __func__);
return (FIDO_ERR_INTERNAL);
}
n->manifest_func = f;
n->next = manifest_funcs;
manifest_funcs = n;
return (FIDO_OK);
}
void
fido_dev_unregister_manifest_func(const dev_manifest_func_t f)
{
dev_manifest_func_node_t *prev, *curr;
find_manifest_func_node(f, &curr, &prev);
if (curr == NULL)
return;
if (prev != NULL)
prev->next = curr->next;
else
manifest_funcs = curr->next;
free(curr);
}
int
fido_dev_info_manifest(fido_dev_info_t *devlist, size_t ilen, size_t *olen)
{
dev_manifest_func_node_t *curr = NULL;
dev_manifest_func_t m_func;
size_t curr_olen;
int r;
*olen = 0;
if (fido_dev_register_manifest_func(fido_hid_manifest) != FIDO_OK)
return (FIDO_ERR_INTERNAL);
#ifdef NFC_LINUX
if (fido_dev_register_manifest_func(fido_nfc_manifest) != FIDO_OK)
return (FIDO_ERR_INTERNAL);
#endif
#ifdef USE_WINHELLO
if (fido_dev_register_manifest_func(fido_winhello_manifest) != FIDO_OK)
return (FIDO_ERR_INTERNAL);
#endif
for (curr = manifest_funcs; curr != NULL; curr = curr->next) {
curr_olen = 0;
m_func = curr->manifest_func;
r = m_func(devlist + *olen, ilen - *olen, &curr_olen);
if (r != FIDO_OK)
return (r);
*olen += curr_olen;
if (*olen == ilen)
break;
}
return (FIDO_OK);
}
int
fido_dev_open_with_info(fido_dev_t *dev)
{
if (dev->path == NULL)
return (FIDO_ERR_INVALID_ARGUMENT);
return (fido_dev_open_wait(dev, dev->path, -1));
}
int
fido_dev_open(fido_dev_t *dev, const char *path)
{
#ifdef NFC_LINUX
/*
* this is a hack to get existing applications up and running with nfc;
* it will *NOT* be part of a libfido2 release. to support nfc in your
* application, please change it to use fido_dev_open_with_info().
*/
if (strncmp(path, "/sys", strlen("/sys")) == 0 && strlen(path) > 4 &&
path[strlen(path) - 4] == 'n' && path[strlen(path) - 3] == 'f' &&
path[strlen(path) - 2] == 'c') {
dev->io_own = true;
dev->io = (fido_dev_io_t) {
fido_nfc_open,
fido_nfc_close,
fido_nfc_read,
fido_nfc_write,
};
dev->transport = (fido_dev_transport_t) {
fido_nfc_rx,
fido_nfc_tx,
};
}
#endif
return (fido_dev_open_wait(dev, path, -1));
}
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_own || dev->io_handle == NULL || sigmask == NULL)
return (FIDO_ERR_INVALID_ARGUMENT);
#ifdef NFC_LINUX
if (dev->transport.rx == fido_nfc_rx)
return (fido_nfc_set_sigmask(dev->io_handle, sigmask));
#endif
return (fido_hid_set_sigmask(dev->io_handle, sigmask));
}
int
fido_dev_cancel(fido_dev_t *dev)
{
#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) < 0)
return (FIDO_ERR_TX);
return (FIDO_OK);
}
int
fido_dev_get_touch_begin(fido_dev_t *dev)
{
fido_blob_t f;
cbor_item_t *argv[9];
const char *clientdata = FIDO_DUMMY_CLIENTDATA;
const uint8_t user_id = FIDO_DUMMY_USER_ID;
unsigned char cdh[SHA256_DIGEST_LENGTH];
fido_rp_t rp;
fido_user_t user;
int r = FIDO_ERR_INTERNAL;
memset(&f, 0, sizeof(f));
memset(argv, 0, sizeof(argv));
memset(cdh, 0, sizeof(cdh));
memset(&rp, 0, sizeof(rp));
memset(&user, 0, sizeof(user));
if (fido_dev_is_fido2(dev) == false)
return (u2f_get_touch_begin(dev));
if (SHA256((const void *)clientdata, strlen(clientdata), cdh) != cdh) {
fido_log_debug("%s: sha256", __func__);
return (FIDO_ERR_INTERNAL);
}
if ((rp.id = strdup(FIDO_DUMMY_RP_ID)) == NULL ||
(user.name = strdup(FIDO_DUMMY_USER_NAME)) == NULL) {
fido_log_debug("%s: strdup", __func__);
goto fail;
}
if (fido_blob_set(&user.id, &user_id, sizeof(user_id)) < 0) {
fido_log_debug("%s: fido_blob_set", __func__);
goto fail;
}
if ((argv[0] = cbor_build_bytestring(cdh, sizeof(cdh))) == NULL ||
(argv[1] = cbor_encode_rp_entity(&rp)) == NULL ||
(argv[2] = cbor_encode_user_entity(&user)) == NULL ||
(argv[3] = cbor_encode_pubkey_param(COSE_ES256)) == NULL) {
fido_log_debug("%s: cbor encode", __func__);
goto fail;
}
if (fido_dev_supports_pin(dev)) {
if ((argv[7] = cbor_new_definite_bytestring()) == NULL ||
(argv[8] = cbor_encode_pin_opt(dev)) == NULL) {
fido_log_debug("%s: cbor encode", __func__);
goto fail;
}
}
if (cbor_build_frame(CTAP_CBOR_MAKECRED, argv, nitems(argv), &f) < 0 ||
fido_tx(dev, CTAP_CMD_CBOR, f.ptr, f.len) < 0) {
fido_log_debug("%s: fido_tx", __func__);
r = FIDO_ERR_TX;
goto fail;
}
r = FIDO_OK;
fail:
cbor_vector_free(argv, nitems(argv));
free(f.ptr);
free(rp.id);
free(user.name);
free(user.id.ptr);
return (r);
}
int
fido_dev_get_touch_status(fido_dev_t *dev, int *touched, int ms)
{
int r;
*touched = 0;
if (fido_dev_is_fido2(dev) == false)
return (u2f_get_touch_status(dev, touched, ms));
switch ((r = fido_rx_cbor_status(dev, ms))) {
case FIDO_ERR_PIN_AUTH_INVALID:
case FIDO_ERR_PIN_INVALID:
case FIDO_ERR_PIN_NOT_SET:
case FIDO_ERR_SUCCESS:
*touched = 1;
break;
case FIDO_ERR_RX:
/* ignore */
break;
default:
fido_log_debug("%s: fido_rx_cbor_status", __func__);
return (r);
}
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_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->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;
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);
}