/*
* Copyright (c) 2019 Markus Friedl
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "includes.h"
#ifdef ENABLE_SK_INTERNAL
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stddef.h>
#include <stdarg.h>
#ifdef HAVE_SHA2_H
#include <sha2.h>
#endif
#ifdef WITH_OPENSSL
#include <openssl/opensslv.h>
#include <openssl/crypto.h>
#include <openssl/bn.h>
#include <openssl/ec.h>
#include <openssl/ecdsa.h>
#include <openssl/evp.h>
#endif /* WITH_OPENSSL */
#include <fido.h>
#include <fido/credman.h>
#ifndef SK_STANDALONE
# include "log.h"
# include "xmalloc.h"
/*
* If building as part of OpenSSH, then rename exported functions.
* This must be done before including sk-api.h.
*/
# define sk_api_version ssh_sk_api_version
# define sk_enroll ssh_sk_enroll
# define sk_sign ssh_sk_sign
# define sk_load_resident_keys ssh_sk_load_resident_keys
#endif /* !SK_STANDALONE */
#include "sk-api.h"
/* #define SK_DEBUG 1 */
#define MAX_FIDO_DEVICES 256
/* Compatibility with OpenSSH 1.0.x */
#if (OPENSSL_VERSION_NUMBER < 0x10100000L)
#define ECDSA_SIG_get0(sig, pr, ps) \
do { \
(*pr) = sig->r; \
(*ps) = sig->s; \
} while (0)
#endif
/* Return the version of the middleware API */
uint32_t sk_api_version(void);
/* Enroll a U2F key (private key generation) */
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);
/* Sign a challenge */
int sk_sign(uint32_t alg, const uint8_t *message, size_t message_len,
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);
/* Load resident keys */
int sk_load_resident_keys(const char *pin, struct sk_option **options,
struct sk_resident_key ***rks, size_t *nrks);
static void skdebug(const char *func, const char *fmt, ...)
__attribute__((__format__ (printf, 2, 3)));
static void
skdebug(const char *func, const char *fmt, ...)
{
#if !defined(SK_STANDALONE)
char *msg;
va_list ap;
va_start(ap, fmt);
xvasprintf(&msg, fmt, ap);
va_end(ap);
debug("%s: %s", func, msg);
free(msg);
#elif defined(SK_DEBUG)
va_list ap;
va_start(ap, fmt);
fprintf(stderr, "%s: ", func);
vfprintf(stderr, fmt, ap);
fputc('\n', stderr);
va_end(ap);
#else
(void)func; /* XXX */
(void)fmt; /* XXX */
#endif
}
uint32_t
sk_api_version(void)
{
return SSH_SK_VERSION_MAJOR;
}
/* Select the first identified FIDO device attached to the system */
static char *
pick_first_device(void)
{
char *ret = NULL;
fido_dev_info_t *devlist = NULL;
size_t olen = 0;
int r;
const fido_dev_info_t *di;
if ((devlist = fido_dev_info_new(1)) == NULL) {
skdebug(__func__, "fido_dev_info_new failed");
goto out;
}
if ((r = fido_dev_info_manifest(devlist, 1, &olen)) != FIDO_OK) {
skdebug(__func__, "fido_dev_info_manifest failed: %s",
fido_strerr(r));
goto out;
}
if (olen != 1) {
skdebug(__func__, "fido_dev_info_manifest bad len %zu", olen);
goto