mirror of git://anongit.mindrot.org/openssh.git
1478 lines
38 KiB
C
1478 lines
38 KiB
C
/* $OpenBSD: sk-usbhid.c,v 1.46 2023/03/28 06:12:38 dtucker Exp $ */
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/*
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* Copyright (c) 2019 Markus Friedl
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* Copyright (c) 2020 Pedro Martelletto
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include "includes.h"
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#ifdef ENABLE_SK_INTERNAL
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdio.h>
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#include <stddef.h>
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#include <stdarg.h>
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#include <time.h>
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#ifdef HAVE_SHA2_H
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#include <sha2.h>
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#endif
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/*
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* Almost every use of OpenSSL in this file is for ECDSA-NISTP256.
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* This is strictly a larger hammer than necessary, but it reduces changes
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* with upstream.
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*/
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#ifndef OPENSSL_HAS_ECC
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# undef WITH_OPENSSL
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#endif
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#ifdef WITH_OPENSSL
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#include <openssl/opensslv.h>
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#include <openssl/crypto.h>
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#include <openssl/bn.h>
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#include <openssl/ec.h>
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#include <openssl/ecdsa.h>
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#include <openssl/evp.h>
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#endif /* WITH_OPENSSL */
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#include <fido.h>
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#include <fido/credman.h>
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/* backwards compat for libfido2 */
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#ifndef HAVE_FIDO_CRED_PROT
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#define fido_cred_prot(x) (0)
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#endif
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#ifndef HAVE_FIDO_CRED_SET_PROT
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#define fido_cred_set_prot(x, y) (FIDO_ERR_UNSUPPORTED_OPTION)
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#endif
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#ifndef HAVE_FIDO_DEV_SUPPORTS_CRED_PROT
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#define fido_dev_supports_cred_prot(x) (0)
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#endif
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#ifndef HAVE_FIDO_DEV_GET_TOUCH_BEGIN
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#define fido_dev_get_touch_begin(x) (FIDO_ERR_UNSUPPORTED_OPTION)
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#endif
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#ifndef HAVE_FIDO_DEV_GET_TOUCH_STATUS
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#define fido_dev_get_touch_status(x, y, z) (FIDO_ERR_UNSUPPORTED_OPTION)
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#endif
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#ifndef FIDO_CRED_PROT_UV_REQUIRED
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#define FIDO_CRED_PROT_UV_REQUIRED 0
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#endif
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#ifndef FIDO_CRED_PROT_UV_OPTIONAL_WITH_ID
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#define FIDO_CRED_PROT_UV_OPTIONAL_WITH_ID 0
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#endif
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#ifndef SK_STANDALONE
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# include "log.h"
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# include "xmalloc.h"
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# include "misc.h"
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/*
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* If building as part of OpenSSH, then rename exported functions.
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* This must be done before including sk-api.h.
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*/
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# define sk_api_version ssh_sk_api_version
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# define sk_enroll ssh_sk_enroll
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# define sk_sign ssh_sk_sign
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# define sk_load_resident_keys ssh_sk_load_resident_keys
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#endif /* !SK_STANDALONE */
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#include "sk-api.h"
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/* #define SK_DEBUG 1 */
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#ifdef SK_DEBUG
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#define SSH_FIDO_INIT_ARG FIDO_DEBUG
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#else
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#define SSH_FIDO_INIT_ARG 0
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#endif
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#define MAX_FIDO_DEVICES 8
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#define FIDO_POLL_MS 50
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#define SELECT_MS 15000
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#define POLL_SLEEP_NS 200000000
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#ifndef FIDO_ERR_OPERATION_DENIED
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#define FIDO_ERR_OPERATION_DENIED 0x27
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#endif
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struct sk_usbhid {
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fido_dev_t *dev;
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char *path;
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};
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/* Return the version of the middleware API */
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uint32_t sk_api_version(void);
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/* Enroll a U2F key (private key generation) */
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int sk_enroll(uint32_t alg, const uint8_t *challenge, size_t challenge_len,
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const char *application, uint8_t flags, const char *pin,
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struct sk_option **options, struct sk_enroll_response **enroll_response);
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/* Sign a challenge */
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int sk_sign(uint32_t alg, const uint8_t *data, size_t data_len,
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const char *application, const uint8_t *key_handle, size_t key_handle_len,
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uint8_t flags, const char *pin, struct sk_option **options,
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struct sk_sign_response **sign_response);
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/* Load resident keys */
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int sk_load_resident_keys(const char *pin, struct sk_option **options,
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struct sk_resident_key ***rks, size_t *nrks);
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static void skdebug(const char *func, const char *fmt, ...)
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__attribute__((__format__ (printf, 2, 3)));
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static void
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skdebug(const char *func, const char *fmt, ...)
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{
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#if !defined(SK_STANDALONE)
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char *msg;
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va_list ap;
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va_start(ap, fmt);
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xvasprintf(&msg, fmt, ap);
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va_end(ap);
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debug("%s: %s", func, msg);
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free(msg);
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#elif defined(SK_DEBUG)
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va_list ap;
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va_start(ap, fmt);
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fprintf(stderr, "%s: ", func);
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vfprintf(stderr, fmt, ap);
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fputc('\n', stderr);
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va_end(ap);
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#else
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(void)func; /* XXX */
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(void)fmt; /* XXX */
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#endif
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}
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uint32_t
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sk_api_version(void)
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{
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return SSH_SK_VERSION_MAJOR;
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}
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static struct sk_usbhid *
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sk_open(const char *path)
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{
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struct sk_usbhid *sk;
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int r;
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if (path == NULL) {
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skdebug(__func__, "path == NULL");
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return NULL;
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}
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if ((sk = calloc(1, sizeof(*sk))) == NULL) {
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skdebug(__func__, "calloc sk failed");
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return NULL;
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}
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if ((sk->path = strdup(path)) == NULL) {
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skdebug(__func__, "strdup path failed");
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free(sk);
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return NULL;
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}
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if ((sk->dev = fido_dev_new()) == NULL) {
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skdebug(__func__, "fido_dev_new failed");
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free(sk->path);
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free(sk);
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return NULL;
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}
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if ((r = fido_dev_open(sk->dev, sk->path)) != FIDO_OK) {
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skdebug(__func__, "fido_dev_open %s failed: %s", sk->path,
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fido_strerr(r));
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fido_dev_free(&sk->dev);
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free(sk->path);
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free(sk);
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return NULL;
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}
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return sk;
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}
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static void
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sk_close(struct sk_usbhid *sk)
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{
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if (sk == NULL)
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return;
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fido_dev_cancel(sk->dev); /* cancel any pending operation */
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fido_dev_close(sk->dev);
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fido_dev_free(&sk->dev);
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free(sk->path);
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free(sk);
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}
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static struct sk_usbhid **
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sk_openv(const fido_dev_info_t *devlist, size_t ndevs, size_t *nopen)
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{
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const fido_dev_info_t *di;
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struct sk_usbhid **skv;
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size_t i;
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*nopen = 0;
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if ((skv = calloc(ndevs, sizeof(*skv))) == NULL) {
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skdebug(__func__, "calloc skv failed");
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return NULL;
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}
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for (i = 0; i < ndevs; i++) {
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if ((di = fido_dev_info_ptr(devlist, i)) == NULL)
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skdebug(__func__, "fido_dev_info_ptr failed");
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else if ((skv[*nopen] = sk_open(fido_dev_info_path(di))) == NULL)
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skdebug(__func__, "sk_open failed");
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else
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(*nopen)++;
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}
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if (*nopen == 0) {
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for (i = 0; i < ndevs; i++)
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sk_close(skv[i]);
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free(skv);
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skv = NULL;
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}
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return skv;
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}
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static void
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sk_closev(struct sk_usbhid **skv, size_t nsk)
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{
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size_t i;
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for (i = 0; i < nsk; i++)
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sk_close(skv[i]);
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free(skv);
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}
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static int
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sk_touch_begin(struct sk_usbhid **skv, size_t nsk)
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{
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size_t i, ok = 0;
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int r;
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for (i = 0; i < nsk; i++)
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if ((r = fido_dev_get_touch_begin(skv[i]->dev)) != FIDO_OK)
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skdebug(__func__, "fido_dev_get_touch_begin %s failed:"
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" %s", skv[i]->path, fido_strerr(r));
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else
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ok++;
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return ok ? 0 : -1;
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}
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static int
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sk_touch_poll(struct sk_usbhid **skv, size_t nsk, int *touch, size_t *idx)
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{
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struct timespec ts_pause;
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size_t npoll, i;
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int r;
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ts_pause.tv_sec = 0;
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ts_pause.tv_nsec = POLL_SLEEP_NS;
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nanosleep(&ts_pause, NULL);
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npoll = nsk;
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for (i = 0; i < nsk; i++) {
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if (skv[i] == NULL)
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continue; /* device discarded */
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skdebug(__func__, "polling %s", skv[i]->path);
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if ((r = fido_dev_get_touch_status(skv[i]->dev, touch,
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FIDO_POLL_MS)) != FIDO_OK) {
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skdebug(__func__, "fido_dev_get_touch_status %s: %s",
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skv[i]->path, fido_strerr(r));
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sk_close(skv[i]); /* discard device */
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skv[i] = NULL;
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if (--npoll == 0) {
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skdebug(__func__, "no device left to poll");
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return -1;
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}
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} else if (*touch) {
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*idx = i;
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return 0;
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}
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}
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*touch = 0;
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return 0;
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}
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#if !defined(HAVE_FIDO_ASSERT_SET_CLIENTDATA) || \
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!defined(HAVE_FIDO_CRED_SET_CLIENTDATA)
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/* Calculate SHA256(m) */
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static int
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sha256_mem(const void *m, size_t mlen, u_char *d, size_t dlen)
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{
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#ifdef WITH_OPENSSL
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u_int mdlen;
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#else
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SHA2_CTX ctx;
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#endif
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if (dlen != 32)
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return -1;
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#ifdef WITH_OPENSSL
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mdlen = dlen;
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if (!EVP_Digest(m, mlen, d, &mdlen, EVP_sha256(), NULL))
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return -1;
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#else
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SHA256Init(&ctx);
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SHA256Update(&ctx, (const uint8_t *)m, mlen);
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SHA256Final(d, &ctx);
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#endif
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return 0;
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}
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#endif /* !HAVE_FIDO_ASSERT_SET_CLIENTDATA || !HAVE_FIDO_CRED_SET_CLIENTDATA */
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#ifndef HAVE_FIDO_CRED_SET_CLIENTDATA
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static int
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fido_cred_set_clientdata(fido_cred_t *cred, const u_char *ptr, size_t len)
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{
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uint8_t d[32];
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int r;
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if (sha256_mem(ptr, len, d, sizeof(d)) != 0) {
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skdebug(__func__, "hash challenge failed");
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return FIDO_ERR_INTERNAL;
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}
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r = fido_cred_set_clientdata_hash(cred, d, sizeof(d));
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explicit_bzero(d, sizeof(d));
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if (r != FIDO_OK) {
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skdebug(__func__, "fido_cred_set_clientdata_hash failed: %s",
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fido_strerr(r));
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}
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return r;
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}
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#endif /* HAVE_FIDO_CRED_SET_CLIENTDATA */
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#ifndef HAVE_FIDO_ASSERT_SET_CLIENTDATA
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static int
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fido_assert_set_clientdata(fido_assert_t *assert, const u_char *ptr, size_t len)
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{
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uint8_t d[32];
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int r;
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if (sha256_mem(ptr, len, d, sizeof(d)) != 0) {
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skdebug(__func__, "hash challenge failed");
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return FIDO_ERR_INTERNAL;
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}
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r = fido_assert_set_clientdata_hash(assert, d, sizeof(d));
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explicit_bzero(d, sizeof(d));
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if (r != FIDO_OK) {
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skdebug(__func__, "fido_assert_set_clientdata_hash failed: %s",
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fido_strerr(r));
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}
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return r;
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}
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#endif /* HAVE_FIDO_ASSERT_SET_CLIENTDATA */
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#ifndef HAVE_FIDO_DEV_IS_WINHELLO
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static bool
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fido_dev_is_winhello(const fido_dev_t *fdev)
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{
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return 0;
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}
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#endif /* HAVE_FIDO_DEV_IS_WINHELLO */
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/* Check if the specified key handle exists on a given sk. */
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static int
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sk_try(const struct sk_usbhid *sk, const char *application,
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const uint8_t *key_handle, size_t key_handle_len)
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{
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fido_assert_t *assert = NULL;
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int r = FIDO_ERR_INTERNAL;
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uint8_t message[32];
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memset(message, '\0', sizeof(message));
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if ((assert = fido_assert_new()) == NULL) {
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skdebug(__func__, "fido_assert_new failed");
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goto out;
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}
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/* generate an invalid signature on FIDO2 tokens */
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if ((r = fido_assert_set_clientdata(assert, message,
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sizeof(message))) != FIDO_OK) {
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skdebug(__func__, "fido_assert_set_clientdata: %s",
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fido_strerr(r));
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goto out;
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}
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if ((r = fido_assert_set_rp(assert, application)) != FIDO_OK) {
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skdebug(__func__, "fido_assert_set_rp: %s", fido_strerr(r));
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goto out;
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}
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if ((r = fido_assert_allow_cred(assert, key_handle,
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key_handle_len)) != FIDO_OK) {
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skdebug(__func__, "fido_assert_allow_cred: %s", fido_strerr(r));
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goto out;
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}
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if ((r = fido_assert_set_up(assert, FIDO_OPT_FALSE)) != FIDO_OK) {
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skdebug(__func__, "fido_assert_up: %s", fido_strerr(r));
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goto out;
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}
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r = fido_dev_get_assert(sk->dev, assert, NULL);
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skdebug(__func__, "fido_dev_get_assert: %s", fido_strerr(r));
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if (r == FIDO_ERR_USER_PRESENCE_REQUIRED) {
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/* U2F tokens may return this */
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r = FIDO_OK;
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}
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out:
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fido_assert_free(&assert);
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|
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return r != FIDO_OK ? -1 : 0;
|
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}
|
|
|
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static int
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check_sk_options(fido_dev_t *dev, const char *opt, int *ret)
|
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{
|
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fido_cbor_info_t *info;
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char * const *name;
|
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const bool *value;
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size_t len, i;
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int r;
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|
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*ret = -1;
|
|
|
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if (!fido_dev_is_fido2(dev)) {
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skdebug(__func__, "device is not fido2");
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return 0;
|
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}
|
|
if ((info = fido_cbor_info_new()) == NULL) {
|
|
skdebug(__func__, "fido_cbor_info_new failed");
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return -1;
|
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}
|
|
if ((r = fido_dev_get_cbor_info(dev, info)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_dev_get_cbor_info: %s", fido_strerr(r));
|
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fido_cbor_info_free(&info);
|
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return -1;
|
|
}
|
|
name = fido_cbor_info_options_name_ptr(info);
|
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value = fido_cbor_info_options_value_ptr(info);
|
|
len = fido_cbor_info_options_len(info);
|
|
for (i = 0; i < len; i++) {
|
|
if (!strcmp(name[i], opt)) {
|
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*ret = value[i];
|
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break;
|
|
}
|
|
}
|
|
fido_cbor_info_free(&info);
|
|
if (*ret == -1)
|
|
skdebug(__func__, "option %s is unknown", opt);
|
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else
|
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skdebug(__func__, "option %s is %s", opt, *ret ? "on" : "off");
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|
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return 0;
|
|
}
|
|
|
|
static struct sk_usbhid *
|
|
sk_select_by_cred(const fido_dev_info_t *devlist, size_t ndevs,
|
|
const char *application, const uint8_t *key_handle, size_t key_handle_len)
|
|
{
|
|
struct sk_usbhid **skv, *sk;
|
|
size_t skvcnt, i;
|
|
int internal_uv;
|
|
|
|
if ((skv = sk_openv(devlist, ndevs, &skvcnt)) == NULL) {
|
|
skdebug(__func__, "sk_openv failed");
|
|
return NULL;
|
|
}
|
|
if (skvcnt == 1 && check_sk_options(skv[0]->dev, "uv",
|
|
&internal_uv) == 0 && internal_uv != -1) {
|
|
sk = skv[0];
|
|
skv[0] = NULL;
|
|
goto out;
|
|
}
|
|
sk = NULL;
|
|
for (i = 0; i < skvcnt; i++) {
|
|
if (sk_try(skv[i], application, key_handle,
|
|
key_handle_len) == 0) {
|
|
sk = skv[i];
|
|
skv[i] = NULL;
|
|
skdebug(__func__, "found key in %s", sk->path);
|
|
break;
|
|
}
|
|
}
|
|
out:
|
|
sk_closev(skv, skvcnt);
|
|
return sk;
|
|
}
|
|
|
|
static struct sk_usbhid *
|
|
sk_select_by_touch(const fido_dev_info_t *devlist, size_t ndevs)
|
|
{
|
|
struct sk_usbhid **skv, *sk;
|
|
struct timeval tv_start, tv_now, tv_delta;
|
|
size_t skvcnt, idx;
|
|
int touch, ms_remain;
|
|
|
|
if ((skv = sk_openv(devlist, ndevs, &skvcnt)) == NULL) {
|
|
skdebug(__func__, "sk_openv failed");
|
|
return NULL;
|
|
}
|
|
sk = NULL;
|
|
if (skvcnt < 2) {
|
|
if (skvcnt == 1) {
|
|
/* single candidate */
|
|
sk = skv[0];
|
|
skv[0] = NULL;
|
|
}
|
|
goto out;
|
|
}
|
|
#ifndef HAVE_FIDO_DEV_GET_TOUCH_STATUS
|
|
skdebug(__func__, "libfido2 version does not support a feature needed for multiple tokens. Please upgrade to >=1.5.0");
|
|
goto out;
|
|
#endif
|
|
|
|
if (sk_touch_begin(skv, skvcnt) == -1) {
|
|
skdebug(__func__, "sk_touch_begin failed");
|
|
goto out;
|
|
}
|
|
monotime_tv(&tv_start);
|
|
do {
|
|
if (sk_touch_poll(skv, skvcnt, &touch, &idx) == -1) {
|
|
skdebug(__func__, "sk_touch_poll failed");
|
|
goto out;
|
|
}
|
|
if (touch) {
|
|
sk = skv[idx];
|
|
skv[idx] = NULL;
|
|
goto out;
|
|
}
|
|
monotime_tv(&tv_now);
|
|
timersub(&tv_now, &tv_start, &tv_delta);
|
|
ms_remain = SELECT_MS - tv_delta.tv_sec * 1000 -
|
|
tv_delta.tv_usec / 1000;
|
|
} while (ms_remain >= FIDO_POLL_MS);
|
|
skdebug(__func__, "timeout");
|
|
out:
|
|
sk_closev(skv, skvcnt);
|
|
return sk;
|
|
}
|
|
|
|
static struct sk_usbhid *
|
|
sk_probe(const char *application, const uint8_t *key_handle,
|
|
size_t key_handle_len, int probe_resident)
|
|
{
|
|
struct sk_usbhid *sk;
|
|
fido_dev_info_t *devlist;
|
|
size_t ndevs;
|
|
int r;
|
|
|
|
#ifdef HAVE_CYGWIN
|
|
if (!probe_resident && (sk = sk_open("windows://hello")) != NULL)
|
|
return sk;
|
|
#endif /* HAVE_CYGWIN */
|
|
if ((devlist = fido_dev_info_new(MAX_FIDO_DEVICES)) == NULL) {
|
|
skdebug(__func__, "fido_dev_info_new failed");
|
|
return NULL;
|
|
}
|
|
if ((r = fido_dev_info_manifest(devlist, MAX_FIDO_DEVICES,
|
|
&ndevs)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_dev_info_manifest failed: %s",
|
|
fido_strerr(r));
|
|
fido_dev_info_free(&devlist, MAX_FIDO_DEVICES);
|
|
return NULL;
|
|
}
|
|
skdebug(__func__, "%zu device(s) detected", ndevs);
|
|
if (ndevs == 0) {
|
|
sk = NULL;
|
|
} else if (application != NULL && key_handle != NULL) {
|
|
skdebug(__func__, "selecting sk by cred");
|
|
sk = sk_select_by_cred(devlist, ndevs, application, key_handle,
|
|
key_handle_len);
|
|
} else {
|
|
skdebug(__func__, "selecting sk by touch");
|
|
sk = sk_select_by_touch(devlist, ndevs);
|
|
}
|
|
fido_dev_info_free(&devlist, MAX_FIDO_DEVICES);
|
|
return sk;
|
|
}
|
|
|
|
#ifdef WITH_OPENSSL
|
|
/*
|
|
* The key returned via fido_cred_pubkey_ptr() is in affine coordinates,
|
|
* but the API expects a SEC1 octet string.
|
|
*/
|
|
static int
|
|
pack_public_key_ecdsa(const fido_cred_t *cred,
|
|
struct sk_enroll_response *response)
|
|
{
|
|
const uint8_t *ptr;
|
|
BIGNUM *x = NULL, *y = NULL;
|
|
EC_POINT *q = NULL;
|
|
EC_GROUP *g = NULL;
|
|
int ret = -1;
|
|
|
|
response->public_key = NULL;
|
|
response->public_key_len = 0;
|
|
|
|
if ((x = BN_new()) == NULL ||
|
|
(y = BN_new()) == NULL ||
|
|
(g = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1)) == NULL ||
|
|
(q = EC_POINT_new(g)) == NULL) {
|
|
skdebug(__func__, "libcrypto setup failed");
|
|
goto out;
|
|
}
|
|
if ((ptr = fido_cred_pubkey_ptr(cred)) == NULL) {
|
|
skdebug(__func__, "fido_cred_pubkey_ptr failed");
|
|
goto out;
|
|
}
|
|
if (fido_cred_pubkey_len(cred) != 64) {
|
|
skdebug(__func__, "bad fido_cred_pubkey_len %zu",
|
|
fido_cred_pubkey_len(cred));
|
|
goto out;
|
|
}
|
|
|
|
if (BN_bin2bn(ptr, 32, x) == NULL ||
|
|
BN_bin2bn(ptr + 32, 32, y) == NULL) {
|
|
skdebug(__func__, "BN_bin2bn failed");
|
|
goto out;
|
|
}
|
|
if (EC_POINT_set_affine_coordinates_GFp(g, q, x, y, NULL) != 1) {
|
|
skdebug(__func__, "EC_POINT_set_affine_coordinates_GFp failed");
|
|
goto out;
|
|
}
|
|
response->public_key_len = EC_POINT_point2oct(g, q,
|
|
POINT_CONVERSION_UNCOMPRESSED, NULL, 0, NULL);
|
|
if (response->public_key_len == 0 || response->public_key_len > 2048) {
|
|
skdebug(__func__, "bad pubkey length %zu",
|
|
response->public_key_len);
|
|
goto out;
|
|
}
|
|
if ((response->public_key = malloc(response->public_key_len)) == NULL) {
|
|
skdebug(__func__, "malloc pubkey failed");
|
|
goto out;
|
|
}
|
|
if (EC_POINT_point2oct(g, q, POINT_CONVERSION_UNCOMPRESSED,
|
|
response->public_key, response->public_key_len, NULL) == 0) {
|
|
skdebug(__func__, "EC_POINT_point2oct failed");
|
|
goto out;
|
|
}
|
|
/* success */
|
|
ret = 0;
|
|
out:
|
|
if (ret != 0 && response->public_key != NULL) {
|
|
memset(response->public_key, 0, response->public_key_len);
|
|
free(response->public_key);
|
|
response->public_key = NULL;
|
|
}
|
|
EC_POINT_free(q);
|
|
EC_GROUP_free(g);
|
|
BN_clear_free(x);
|
|
BN_clear_free(y);
|
|
return ret;
|
|
}
|
|
#endif /* WITH_OPENSSL */
|
|
|
|
static int
|
|
pack_public_key_ed25519(const fido_cred_t *cred,
|
|
struct sk_enroll_response *response)
|
|
{
|
|
const uint8_t *ptr;
|
|
size_t len;
|
|
int ret = -1;
|
|
|
|
response->public_key = NULL;
|
|
response->public_key_len = 0;
|
|
|
|
if ((len = fido_cred_pubkey_len(cred)) != 32) {
|
|
skdebug(__func__, "bad fido_cred_pubkey_len len %zu", len);
|
|
goto out;
|
|
}
|
|
if ((ptr = fido_cred_pubkey_ptr(cred)) == NULL) {
|
|
skdebug(__func__, "fido_cred_pubkey_ptr failed");
|
|
goto out;
|
|
}
|
|
response->public_key_len = len;
|
|
if ((response->public_key = malloc(response->public_key_len)) == NULL) {
|
|
skdebug(__func__, "malloc pubkey failed");
|
|
goto out;
|
|
}
|
|
memcpy(response->public_key, ptr, len);
|
|
ret = 0;
|
|
out:
|
|
if (ret != 0)
|
|
free(response->public_key);
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
pack_public_key(uint32_t alg, const fido_cred_t *cred,
|
|
struct sk_enroll_response *response)
|
|
{
|
|
switch(alg) {
|
|
#ifdef WITH_OPENSSL
|
|
case SSH_SK_ECDSA:
|
|
return pack_public_key_ecdsa(cred, response);
|
|
#endif /* WITH_OPENSSL */
|
|
case SSH_SK_ED25519:
|
|
return pack_public_key_ed25519(cred, response);
|
|
default:
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
static int
|
|
fidoerr_to_skerr(int fidoerr)
|
|
{
|
|
switch (fidoerr) {
|
|
case FIDO_ERR_UNSUPPORTED_OPTION:
|
|
case FIDO_ERR_UNSUPPORTED_ALGORITHM:
|
|
return SSH_SK_ERR_UNSUPPORTED;
|
|
case FIDO_ERR_PIN_REQUIRED:
|
|
case FIDO_ERR_PIN_INVALID:
|
|
case FIDO_ERR_OPERATION_DENIED:
|
|
return SSH_SK_ERR_PIN_REQUIRED;
|
|
default:
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
static int
|
|
check_enroll_options(struct sk_option **options, char **devicep,
|
|
uint8_t *user_id, size_t user_id_len)
|
|
{
|
|
size_t i;
|
|
|
|
if (options == NULL)
|
|
return 0;
|
|
for (i = 0; options[i] != NULL; i++) {
|
|
if (strcmp(options[i]->name, "device") == 0) {
|
|
if ((*devicep = strdup(options[i]->value)) == NULL) {
|
|
skdebug(__func__, "strdup device failed");
|
|
return -1;
|
|
}
|
|
skdebug(__func__, "requested device %s", *devicep);
|
|
} else if (strcmp(options[i]->name, "user") == 0) {
|
|
if (strlcpy(user_id, options[i]->value, user_id_len) >=
|
|
user_id_len) {
|
|
skdebug(__func__, "user too long");
|
|
return -1;
|
|
}
|
|
skdebug(__func__, "requested user %s",
|
|
(char *)user_id);
|
|
} else {
|
|
skdebug(__func__, "requested unsupported option %s",
|
|
options[i]->name);
|
|
if (options[i]->required) {
|
|
skdebug(__func__, "unknown required option");
|
|
return -1;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
key_lookup(fido_dev_t *dev, const char *application, const uint8_t *user_id,
|
|
size_t user_id_len, const char *pin)
|
|
{
|
|
fido_assert_t *assert = NULL;
|
|
uint8_t message[32];
|
|
int r = FIDO_ERR_INTERNAL;
|
|
int sk_supports_uv, uv;
|
|
size_t i;
|
|
|
|
memset(message, '\0', sizeof(message));
|
|
if ((assert = fido_assert_new()) == NULL) {
|
|
skdebug(__func__, "fido_assert_new failed");
|
|
goto out;
|
|
}
|
|
/* generate an invalid signature on FIDO2 tokens */
|
|
if ((r = fido_assert_set_clientdata(assert, message,
|
|
sizeof(message))) != FIDO_OK) {
|
|
skdebug(__func__, "fido_assert_set_clientdata: %s",
|
|
fido_strerr(r));
|
|
goto out;
|
|
}
|
|
if ((r = fido_assert_set_rp(assert, application)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_assert_set_rp: %s", fido_strerr(r));
|
|
goto out;
|
|
}
|
|
if ((r = fido_assert_set_up(assert, FIDO_OPT_FALSE)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_assert_set_up: %s", fido_strerr(r));
|
|
goto out;
|
|
}
|
|
uv = FIDO_OPT_OMIT;
|
|
if (pin == NULL && check_sk_options(dev, "uv", &sk_supports_uv) == 0 &&
|
|
sk_supports_uv != -1)
|
|
uv = FIDO_OPT_TRUE;
|
|
if ((r = fido_assert_set_uv(assert, uv)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_assert_set_uv: %s", fido_strerr(r));
|
|
goto out;
|
|
}
|
|
if ((r = fido_dev_get_assert(dev, assert, pin)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_dev_get_assert: %s", fido_strerr(r));
|
|
goto out;
|
|
}
|
|
r = FIDO_ERR_NO_CREDENTIALS;
|
|
skdebug(__func__, "%zu signatures returned", fido_assert_count(assert));
|
|
for (i = 0; i < fido_assert_count(assert); i++) {
|
|
if (fido_assert_user_id_len(assert, i) == user_id_len &&
|
|
memcmp(fido_assert_user_id_ptr(assert, i), user_id,
|
|
user_id_len) == 0) {
|
|
skdebug(__func__, "credential exists");
|
|
r = FIDO_OK;
|
|
goto out;
|
|
}
|
|
}
|
|
out:
|
|
fido_assert_free(&assert);
|
|
|
|
return r;
|
|
}
|
|
|
|
int
|
|
sk_enroll(uint32_t alg, const uint8_t *challenge, size_t challenge_len,
|
|
const char *application, uint8_t flags, const char *pin,
|
|
struct sk_option **options, struct sk_enroll_response **enroll_response)
|
|
{
|
|
fido_cred_t *cred = NULL;
|
|
const uint8_t *ptr;
|
|
uint8_t user_id[32];
|
|
struct sk_usbhid *sk = NULL;
|
|
struct sk_enroll_response *response = NULL;
|
|
size_t len;
|
|
int credprot;
|
|
int cose_alg;
|
|
int ret = SSH_SK_ERR_GENERAL;
|
|
int r;
|
|
char *device = NULL;
|
|
|
|
fido_init(SSH_FIDO_INIT_ARG);
|
|
|
|
if (enroll_response == NULL) {
|
|
skdebug(__func__, "enroll_response == NULL");
|
|
goto out;
|
|
}
|
|
*enroll_response = NULL;
|
|
memset(user_id, 0, sizeof(user_id));
|
|
if (check_enroll_options(options, &device, user_id,
|
|
sizeof(user_id)) != 0)
|
|
goto out; /* error already logged */
|
|
|
|
switch(alg) {
|
|
#ifdef WITH_OPENSSL
|
|
case SSH_SK_ECDSA:
|
|
cose_alg = COSE_ES256;
|
|
break;
|
|
#endif /* WITH_OPENSSL */
|
|
case SSH_SK_ED25519:
|
|
cose_alg = COSE_EDDSA;
|
|
break;
|
|
default:
|
|
skdebug(__func__, "unsupported key type %d", alg);
|
|
goto out;
|
|
}
|
|
if (device != NULL)
|
|
sk = sk_open(device);
|
|
else
|
|
sk = sk_probe(NULL, NULL, 0, 0);
|
|
if (sk == NULL) {
|
|
ret = SSH_SK_ERR_DEVICE_NOT_FOUND;
|
|
skdebug(__func__, "failed to find sk");
|
|
goto out;
|
|
}
|
|
skdebug(__func__, "using device %s", sk->path);
|
|
if ((flags & SSH_SK_RESIDENT_KEY) != 0 &&
|
|
(flags & SSH_SK_FORCE_OPERATION) == 0 &&
|
|
(r = key_lookup(sk->dev, application, user_id, sizeof(user_id),
|
|
pin)) != FIDO_ERR_NO_CREDENTIALS) {
|
|
if (r != FIDO_OK) {
|
|
ret = fidoerr_to_skerr(r);
|
|
skdebug(__func__, "key_lookup failed");
|
|
} else {
|
|
ret = SSH_SK_ERR_CREDENTIAL_EXISTS;
|
|
skdebug(__func__, "key exists");
|
|
}
|
|
goto out;
|
|
}
|
|
if ((cred = fido_cred_new()) == NULL) {
|
|
skdebug(__func__, "fido_cred_new failed");
|
|
goto out;
|
|
}
|
|
if ((r = fido_cred_set_type(cred, cose_alg)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_cred_set_type: %s", fido_strerr(r));
|
|
goto out;
|
|
}
|
|
if ((r = fido_cred_set_clientdata(cred,
|
|
challenge, challenge_len)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_cred_set_clientdata: %s",
|
|
fido_strerr(r));
|
|
goto out;
|
|
}
|
|
if ((r = fido_cred_set_rk(cred, (flags & SSH_SK_RESIDENT_KEY) != 0 ?
|
|
FIDO_OPT_TRUE : FIDO_OPT_OMIT)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_cred_set_rk: %s", fido_strerr(r));
|
|
goto out;
|
|
}
|
|
if ((r = fido_cred_set_user(cred, user_id, sizeof(user_id),
|
|
"openssh", "openssh", NULL)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_cred_set_user: %s", fido_strerr(r));
|
|
goto out;
|
|
}
|
|
if ((r = fido_cred_set_rp(cred, application, NULL)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_cred_set_rp: %s", fido_strerr(r));
|
|
goto out;
|
|
}
|
|
if ((flags & (SSH_SK_RESIDENT_KEY|SSH_SK_USER_VERIFICATION_REQD)) != 0) {
|
|
#if !defined(HAVE_FIDO_DEV_SUPPORTS_CRED_PROT) || \
|
|
!defined(HAVE_FIDO_CRED_SET_PROT)
|
|
skdebug(__func__, "libfido2 version does not support a feature required for this operation. Please upgrade to >=1.5.0");
|
|
ret = SSH_SK_ERR_UNSUPPORTED;
|
|
goto out;
|
|
credprot = 0; (void)credprot; /* avoid warning */
|
|
#endif
|
|
if (!fido_dev_supports_cred_prot(sk->dev)) {
|
|
skdebug(__func__, "%s does not support credprot, "
|
|
"refusing to create unprotected "
|
|
"resident/verify-required key", sk->path);
|
|
ret = SSH_SK_ERR_UNSUPPORTED;
|
|
goto out;
|
|
}
|
|
if ((flags & SSH_SK_USER_VERIFICATION_REQD))
|
|
credprot = FIDO_CRED_PROT_UV_REQUIRED;
|
|
else
|
|
credprot = FIDO_CRED_PROT_UV_OPTIONAL_WITH_ID;
|
|
|
|
if ((r = fido_cred_set_prot(cred, credprot)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_cred_set_prot: %s",
|
|
fido_strerr(r));
|
|
ret = fidoerr_to_skerr(r);
|
|
goto out;
|
|
}
|
|
}
|
|
if ((r = fido_dev_make_cred(sk->dev, cred, pin)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_dev_make_cred: %s", fido_strerr(r));
|
|
ret = fidoerr_to_skerr(r);
|
|
goto out;
|
|
}
|
|
if (fido_cred_x5c_ptr(cred) != NULL) {
|
|
if ((r = fido_cred_verify(cred)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_cred_verify: %s",
|
|
fido_strerr(r));
|
|
goto out;
|
|
}
|
|
} else {
|
|
skdebug(__func__, "self-attested credential");
|
|
if ((r = fido_cred_verify_self(cred)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_cred_verify_self: %s",
|
|
fido_strerr(r));
|
|
goto out;
|
|
}
|
|
}
|
|
if ((response = calloc(1, sizeof(*response))) == NULL) {
|
|
skdebug(__func__, "calloc response failed");
|
|
goto out;
|
|
}
|
|
response->flags = flags;
|
|
if (pack_public_key(alg, cred, response) != 0) {
|
|
skdebug(__func__, "pack_public_key failed");
|
|
goto out;
|
|
}
|
|
if ((ptr = fido_cred_id_ptr(cred)) != NULL) {
|
|
len = fido_cred_id_len(cred);
|
|
if ((response->key_handle = calloc(1, len)) == NULL) {
|
|
skdebug(__func__, "calloc key handle failed");
|
|
goto out;
|
|
}
|
|
memcpy(response->key_handle, ptr, len);
|
|
response->key_handle_len = len;
|
|
}
|
|
if ((ptr = fido_cred_sig_ptr(cred)) != NULL) {
|
|
len = fido_cred_sig_len(cred);
|
|
if ((response->signature = calloc(1, len)) == NULL) {
|
|
skdebug(__func__, "calloc signature failed");
|
|
goto out;
|
|
}
|
|
memcpy(response->signature, ptr, len);
|
|
response->signature_len = len;
|
|
}
|
|
if ((ptr = fido_cred_x5c_ptr(cred)) != NULL) {
|
|
len = fido_cred_x5c_len(cred);
|
|
skdebug(__func__, "attestation cert len=%zu", len);
|
|
if ((response->attestation_cert = calloc(1, len)) == NULL) {
|
|
skdebug(__func__, "calloc attestation cert failed");
|
|
goto out;
|
|
}
|
|
memcpy(response->attestation_cert, ptr, len);
|
|
response->attestation_cert_len = len;
|
|
}
|
|
if ((ptr = fido_cred_authdata_ptr(cred)) != NULL) {
|
|
len = fido_cred_authdata_len(cred);
|
|
skdebug(__func__, "authdata len=%zu", len);
|
|
if ((response->authdata = calloc(1, len)) == NULL) {
|
|
skdebug(__func__, "calloc authdata failed");
|
|
goto out;
|
|
}
|
|
memcpy(response->authdata, ptr, len);
|
|
response->authdata_len = len;
|
|
}
|
|
*enroll_response = response;
|
|
response = NULL;
|
|
ret = 0;
|
|
out:
|
|
free(device);
|
|
if (response != NULL) {
|
|
free(response->public_key);
|
|
free(response->key_handle);
|
|
free(response->signature);
|
|
free(response->attestation_cert);
|
|
free(response->authdata);
|
|
free(response);
|
|
}
|
|
sk_close(sk);
|
|
fido_cred_free(&cred);
|
|
return ret;
|
|
}
|
|
|
|
#ifdef WITH_OPENSSL
|
|
static int
|
|
pack_sig_ecdsa(fido_assert_t *assert, struct sk_sign_response *response)
|
|
{
|
|
ECDSA_SIG *sig = NULL;
|
|
const BIGNUM *sig_r, *sig_s;
|
|
const unsigned char *cp;
|
|
size_t sig_len;
|
|
int ret = -1;
|
|
|
|
cp = fido_assert_sig_ptr(assert, 0);
|
|
sig_len = fido_assert_sig_len(assert, 0);
|
|
if ((sig = d2i_ECDSA_SIG(NULL, &cp, sig_len)) == NULL) {
|
|
skdebug(__func__, "d2i_ECDSA_SIG failed");
|
|
goto out;
|
|
}
|
|
ECDSA_SIG_get0(sig, &sig_r, &sig_s);
|
|
response->sig_r_len = BN_num_bytes(sig_r);
|
|
response->sig_s_len = BN_num_bytes(sig_s);
|
|
if ((response->sig_r = calloc(1, response->sig_r_len)) == NULL ||
|
|
(response->sig_s = calloc(1, response->sig_s_len)) == NULL) {
|
|
skdebug(__func__, "calloc signature failed");
|
|
goto out;
|
|
}
|
|
BN_bn2bin(sig_r, response->sig_r);
|
|
BN_bn2bin(sig_s, response->sig_s);
|
|
ret = 0;
|
|
out:
|
|
ECDSA_SIG_free(sig);
|
|
if (ret != 0) {
|
|
free(response->sig_r);
|
|
free(response->sig_s);
|
|
response->sig_r = NULL;
|
|
response->sig_s = NULL;
|
|
}
|
|
return ret;
|
|
}
|
|
#endif /* WITH_OPENSSL */
|
|
|
|
static int
|
|
pack_sig_ed25519(fido_assert_t *assert, struct sk_sign_response *response)
|
|
{
|
|
const unsigned char *ptr;
|
|
size_t len;
|
|
int ret = -1;
|
|
|
|
ptr = fido_assert_sig_ptr(assert, 0);
|
|
len = fido_assert_sig_len(assert, 0);
|
|
if (len != 64) {
|
|
skdebug(__func__, "bad length %zu", len);
|
|
goto out;
|
|
}
|
|
response->sig_r_len = len;
|
|
if ((response->sig_r = calloc(1, response->sig_r_len)) == NULL) {
|
|
skdebug(__func__, "calloc signature failed");
|
|
goto out;
|
|
}
|
|
memcpy(response->sig_r, ptr, len);
|
|
ret = 0;
|
|
out:
|
|
if (ret != 0) {
|
|
free(response->sig_r);
|
|
response->sig_r = NULL;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
pack_sig(uint32_t alg, fido_assert_t *assert,
|
|
struct sk_sign_response *response)
|
|
{
|
|
switch(alg) {
|
|
#ifdef WITH_OPENSSL
|
|
case SSH_SK_ECDSA:
|
|
return pack_sig_ecdsa(assert, response);
|
|
#endif /* WITH_OPENSSL */
|
|
case SSH_SK_ED25519:
|
|
return pack_sig_ed25519(assert, response);
|
|
default:
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
/* Checks sk_options for sk_sign() and sk_load_resident_keys() */
|
|
static int
|
|
check_sign_load_resident_options(struct sk_option **options, char **devicep)
|
|
{
|
|
size_t i;
|
|
|
|
if (options == NULL)
|
|
return 0;
|
|
for (i = 0; options[i] != NULL; i++) {
|
|
if (strcmp(options[i]->name, "device") == 0) {
|
|
if ((*devicep = strdup(options[i]->value)) == NULL) {
|
|
skdebug(__func__, "strdup device failed");
|
|
return -1;
|
|
}
|
|
skdebug(__func__, "requested device %s", *devicep);
|
|
} else {
|
|
skdebug(__func__, "requested unsupported option %s",
|
|
options[i]->name);
|
|
if (options[i]->required) {
|
|
skdebug(__func__, "unknown required option");
|
|
return -1;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
sk_sign(uint32_t alg, const uint8_t *data, size_t datalen,
|
|
const char *application,
|
|
const uint8_t *key_handle, size_t key_handle_len,
|
|
uint8_t flags, const char *pin, struct sk_option **options,
|
|
struct sk_sign_response **sign_response)
|
|
{
|
|
fido_assert_t *assert = NULL;
|
|
char *device = NULL;
|
|
struct sk_usbhid *sk = NULL;
|
|
struct sk_sign_response *response = NULL;
|
|
int ret = SSH_SK_ERR_GENERAL, internal_uv;
|
|
int r;
|
|
|
|
fido_init(SSH_FIDO_INIT_ARG);
|
|
|
|
if (sign_response == NULL) {
|
|
skdebug(__func__, "sign_response == NULL");
|
|
goto out;
|
|
}
|
|
*sign_response = NULL;
|
|
if (check_sign_load_resident_options(options, &device) != 0)
|
|
goto out; /* error already logged */
|
|
if (device != NULL)
|
|
sk = sk_open(device);
|
|
else if (pin != NULL || (flags & SSH_SK_USER_VERIFICATION_REQD))
|
|
sk = sk_probe(NULL, NULL, 0, 0);
|
|
else
|
|
sk = sk_probe(application, key_handle, key_handle_len, 0);
|
|
if (sk == NULL) {
|
|
ret = SSH_SK_ERR_DEVICE_NOT_FOUND;
|
|
skdebug(__func__, "failed to find sk");
|
|
goto out;
|
|
}
|
|
if ((assert = fido_assert_new()) == NULL) {
|
|
skdebug(__func__, "fido_assert_new failed");
|
|
goto out;
|
|
}
|
|
if ((r = fido_assert_set_clientdata(assert,
|
|
data, datalen)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_assert_set_clientdata: %s",
|
|
fido_strerr(r));
|
|
goto out;
|
|
}
|
|
if ((r = fido_assert_set_rp(assert, application)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_assert_set_rp: %s", fido_strerr(r));
|
|
goto out;
|
|
}
|
|
if ((r = fido_assert_allow_cred(assert, key_handle,
|
|
key_handle_len)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_assert_allow_cred: %s", fido_strerr(r));
|
|
goto out;
|
|
}
|
|
if ((r = fido_assert_set_up(assert,
|
|
(flags & SSH_SK_USER_PRESENCE_REQD) ?
|
|
FIDO_OPT_TRUE : FIDO_OPT_FALSE)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_assert_set_up: %s", fido_strerr(r));
|
|
goto out;
|
|
}
|
|
/*
|
|
* WinHello requests the PIN by default. Make "uv" request explicit
|
|
* to allow keys with and without -O verify-required to make sense.
|
|
*/
|
|
if (pin == NULL && fido_dev_is_winhello (sk->dev) &&
|
|
(r = fido_assert_set_uv(assert, FIDO_OPT_FALSE)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_assert_set_uv: %s", fido_strerr(r));
|
|
}
|
|
if (pin == NULL && (flags & SSH_SK_USER_VERIFICATION_REQD)) {
|
|
if (check_sk_options(sk->dev, "uv", &internal_uv) < 0 ||
|
|
internal_uv != 1) {
|
|
skdebug(__func__, "check_sk_options uv");
|
|
ret = SSH_SK_ERR_PIN_REQUIRED;
|
|
goto out;
|
|
}
|
|
if ((r = fido_assert_set_uv(assert,
|
|
FIDO_OPT_TRUE)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_assert_set_uv: %s",
|
|
fido_strerr(r));
|
|
ret = fidoerr_to_skerr(r);
|
|
goto out;
|
|
}
|
|
}
|
|
if ((r = fido_dev_get_assert(sk->dev, assert, pin)) != FIDO_OK) {
|
|
skdebug(__func__, "fido_dev_get_assert: %s", fido_strerr(r));
|
|
ret = fidoerr_to_skerr(r);
|
|
goto out;
|
|
}
|
|
if ((response = calloc(1, sizeof(*response))) == NULL) {
|
|
skdebug(__func__, "calloc response failed");
|
|
goto out;
|
|
}
|
|
response->flags = fido_assert_flags(assert, 0);
|
|
response->counter = fido_assert_sigcount(assert, 0);
|
|
if (pack_sig(alg, assert, response) != 0) {
|
|
skdebug(__func__, "pack_sig failed");
|
|
goto out;
|
|
}
|
|
*sign_response = response;
|
|
response = NULL;
|
|
ret = 0;
|
|
out:
|
|
free(device);
|
|
if (response != NULL) {
|
|
free(response->sig_r);
|
|
free(response->sig_s);
|
|
free(response);
|
|
}
|
|
sk_close(sk);
|
|
fido_assert_free(&assert);
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
read_rks(struct sk_usbhid *sk, const char *pin,
|
|
struct sk_resident_key ***rksp, size_t *nrksp)
|
|
{
|
|
int ret = SSH_SK_ERR_GENERAL, r = -1, internal_uv;
|
|
fido_credman_metadata_t *metadata = NULL;
|
|
fido_credman_rp_t *rp = NULL;
|
|
fido_credman_rk_t *rk = NULL;
|
|
size_t i, j, nrp, nrk, user_id_len;
|
|
const fido_cred_t *cred;
|
|
const char *rp_id, *rp_name, *user_name;
|
|
struct sk_resident_key *srk = NULL, **tmp;
|
|
const u_char *user_id;
|
|
|
|
if (pin == NULL) {
|
|
skdebug(__func__, "no PIN specified");
|
|
ret = SSH_SK_ERR_PIN_REQUIRED;
|
|
goto out;
|
|
}
|
|
if ((metadata = fido_credman_metadata_new()) == NULL) {
|
|
skdebug(__func__, "alloc failed");
|
|
goto out;
|
|
}
|
|
if (check_sk_options(sk->dev, "uv", &internal_uv) != 0) {
|
|
skdebug(__func__, "check_sk_options failed");
|
|
goto out;
|
|
}
|
|
|
|
if ((r = fido_credman_get_dev_metadata(sk->dev, metadata, pin)) != 0) {
|
|
if (r == FIDO_ERR_INVALID_COMMAND) {
|
|
skdebug(__func__, "device %s does not support "
|
|
"resident keys", sk->path);
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
skdebug(__func__, "get metadata for %s failed: %s",
|
|
sk->path, fido_strerr(r));
|
|
ret = fidoerr_to_skerr(r);
|
|
goto out;
|
|
}
|
|
skdebug(__func__, "existing %llu, remaining %llu",
|
|
(unsigned long long)fido_credman_rk_existing(metadata),
|
|
(unsigned long long)fido_credman_rk_remaining(metadata));
|
|
if ((rp = fido_credman_rp_new()) == NULL) {
|
|
skdebug(__func__, "alloc rp failed");
|
|
goto out;
|
|
}
|
|
if ((r = fido_credman_get_dev_rp(sk->dev, rp, pin)) != 0) {
|
|
skdebug(__func__, "get RPs for %s failed: %s",
|
|
sk->path, fido_strerr(r));
|
|
goto out;
|
|
}
|
|
nrp = fido_credman_rp_count(rp);
|
|
skdebug(__func__, "Device %s has resident keys for %zu RPs",
|
|
sk->path, nrp);
|
|
|
|
/* Iterate over RP IDs that have resident keys */
|
|
for (i = 0; i < nrp; i++) {
|
|
rp_id = fido_credman_rp_id(rp, i);
|
|
rp_name = fido_credman_rp_name(rp, i);
|
|
skdebug(__func__, "rp %zu: name=\"%s\" id=\"%s\" hashlen=%zu",
|
|
i, rp_name == NULL ? "(none)" : rp_name,
|
|
rp_id == NULL ? "(none)" : rp_id,
|
|
fido_credman_rp_id_hash_len(rp, i));
|
|
|
|
/* Skip non-SSH RP IDs */
|
|
if (rp_id == NULL ||
|
|
strncasecmp(fido_credman_rp_id(rp, i), "ssh:", 4) != 0)
|
|
continue;
|
|
|
|
fido_credman_rk_free(&rk);
|
|
if ((rk = fido_credman_rk_new()) == NULL) {
|
|
skdebug(__func__, "alloc rk failed");
|
|
goto out;
|
|
}
|
|
if ((r = fido_credman_get_dev_rk(sk->dev,
|
|
fido_credman_rp_id(rp, i), rk, pin)) != 0) {
|
|
skdebug(__func__, "get RKs for %s slot %zu failed: %s",
|
|
sk->path, i, fido_strerr(r));
|
|
goto out;
|
|
}
|
|
nrk = fido_credman_rk_count(rk);
|
|
skdebug(__func__, "RP \"%s\" has %zu resident keys",
|
|
fido_credman_rp_id(rp, i), nrk);
|
|
|
|
/* Iterate over resident keys for this RP ID */
|
|
for (j = 0; j < nrk; j++) {
|
|
if ((cred = fido_credman_rk(rk, j)) == NULL) {
|
|
skdebug(__func__, "no RK in slot %zu", j);
|
|
continue;
|
|
}
|
|
if ((user_name = fido_cred_user_name(cred)) == NULL)
|
|
user_name = "";
|
|
user_id = fido_cred_user_id_ptr(cred);
|
|
user_id_len = fido_cred_user_id_len(cred);
|
|
skdebug(__func__, "Device %s RP \"%s\" user \"%s\" "
|
|
"uidlen %zu slot %zu: type %d flags 0x%02x "
|
|
"prot 0x%02x", sk->path, rp_id, user_name,
|
|
user_id_len, j, fido_cred_type(cred),
|
|
fido_cred_flags(cred), fido_cred_prot(cred));
|
|
|
|
/* build response entry */
|
|
if ((srk = calloc(1, sizeof(*srk))) == NULL ||
|
|
(srk->key.key_handle = calloc(1,
|
|
fido_cred_id_len(cred))) == NULL ||
|
|
(srk->application = strdup(rp_id)) == NULL ||
|
|
(user_id_len > 0 &&
|
|
(srk->user_id = calloc(1, user_id_len)) == NULL)) {
|
|
skdebug(__func__, "alloc sk_resident_key");
|
|
goto out;
|
|
}
|
|
|
|
srk->key.key_handle_len = fido_cred_id_len(cred);
|
|
memcpy(srk->key.key_handle, fido_cred_id_ptr(cred),
|
|
srk->key.key_handle_len);
|
|
srk->user_id_len = user_id_len;
|
|
if (srk->user_id_len != 0)
|
|
memcpy(srk->user_id, user_id, srk->user_id_len);
|
|
|
|
switch (fido_cred_type(cred)) {
|
|
case COSE_ES256:
|
|
srk->alg = SSH_SK_ECDSA;
|
|
break;
|
|
case COSE_EDDSA:
|
|
srk->alg = SSH_SK_ED25519;
|
|
break;
|
|
default:
|
|
skdebug(__func__, "unsupported key type %d",
|
|
fido_cred_type(cred));
|
|
goto out; /* XXX free rk and continue */
|
|
}
|
|
|
|
if (fido_cred_prot(cred) == FIDO_CRED_PROT_UV_REQUIRED
|
|
&& internal_uv == -1)
|
|
srk->flags |= SSH_SK_USER_VERIFICATION_REQD;
|
|
|
|
if ((r = pack_public_key(srk->alg, cred,
|
|
&srk->key)) != 0) {
|
|
skdebug(__func__, "pack public key failed");
|
|
goto out;
|
|
}
|
|
/* append */
|
|
if ((tmp = recallocarray(*rksp, *nrksp, (*nrksp) + 1,
|
|
sizeof(**rksp))) == NULL) {
|
|
skdebug(__func__, "alloc rksp");
|
|
goto out;
|
|
}
|
|
*rksp = tmp;
|
|
(*rksp)[(*nrksp)++] = srk;
|
|
srk = NULL;
|
|
}
|
|
}
|
|
/* Success */
|
|
ret = 0;
|
|
out:
|
|
if (srk != NULL) {
|
|
free(srk->application);
|
|
freezero(srk->key.public_key, srk->key.public_key_len);
|
|
freezero(srk->key.key_handle, srk->key.key_handle_len);
|
|
freezero(srk->user_id, srk->user_id_len);
|
|
freezero(srk, sizeof(*srk));
|
|
}
|
|
fido_credman_rp_free(&rp);
|
|
fido_credman_rk_free(&rk);
|
|
fido_credman_metadata_free(&metadata);
|
|
return ret;
|
|
}
|
|
|
|
int
|
|
sk_load_resident_keys(const char *pin, struct sk_option **options,
|
|
struct sk_resident_key ***rksp, size_t *nrksp)
|
|
{
|
|
int ret = SSH_SK_ERR_GENERAL, r = -1;
|
|
size_t i, nrks = 0;
|
|
struct sk_resident_key **rks = NULL;
|
|
struct sk_usbhid *sk = NULL;
|
|
char *device = NULL;
|
|
|
|
*rksp = NULL;
|
|
*nrksp = 0;
|
|
|
|
fido_init(SSH_FIDO_INIT_ARG);
|
|
|
|
if (check_sign_load_resident_options(options, &device) != 0)
|
|
goto out; /* error already logged */
|
|
if (device != NULL)
|
|
sk = sk_open(device);
|
|
else
|
|
sk = sk_probe(NULL, NULL, 0, 1);
|
|
if (sk == NULL) {
|
|
ret = SSH_SK_ERR_DEVICE_NOT_FOUND;
|
|
skdebug(__func__, "failed to find sk");
|
|
goto out;
|
|
}
|
|
skdebug(__func__, "trying %s", sk->path);
|
|
if ((r = read_rks(sk, pin, &rks, &nrks)) != 0) {
|
|
skdebug(__func__, "read_rks failed for %s", sk->path);
|
|
ret = r;
|
|
goto out;
|
|
}
|
|
/* success, unless we have no keys but a specific error */
|
|
if (nrks > 0 || ret == SSH_SK_ERR_GENERAL)
|
|
ret = 0;
|
|
*rksp = rks;
|
|
*nrksp = nrks;
|
|
rks = NULL;
|
|
nrks = 0;
|
|
out:
|
|
sk_close(sk);
|
|
for (i = 0; i < nrks; i++) {
|
|
free(rks[i]->application);
|
|
freezero(rks[i]->key.public_key, rks[i]->key.public_key_len);
|
|
freezero(rks[i]->key.key_handle, rks[i]->key.key_handle_len);
|
|
freezero(rks[i]->user_id, rks[i]->user_id_len);
|
|
freezero(rks[i], sizeof(*rks[i]));
|
|
}
|
|
free(device);
|
|
free(rks);
|
|
return ret;
|
|
}
|
|
|
|
#endif /* ENABLE_SK_INTERNAL */
|