/* $OpenBSD: sk-api.h,v 1.9 2020/04/28 04:02:29 djm Exp $ */
/*
* Copyright (c) 2019 Google LLC
*
* 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.
*/
#ifndef _SK_API_H
#define _SK_API_H 1
#include <stddef.h>
#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif
/* Flags */
#define SSH_SK_USER_PRESENCE_REQD 0x01
#define SSH_SK_USER_VERIFICATION_REQD 0x04
#define SSH_SK_RESIDENT_KEY 0x20
/* Algs */
#define SSH_SK_ECDSA 0x00
#define SSH_SK_ED25519 0x01
/* Error codes */
#define SSH_SK_ERR_GENERAL -1
#define SSH_SK_ERR_UNSUPPORTED -2
#define SSH_SK_ERR_PIN_REQUIRED -3
#define SSH_SK_ERR_DEVICE_NOT_FOUND -4
struct sk_enroll_response {
uint8_t *public_key;
size_t public_key_len;
uint8_t *key_handle;
size_t key_handle_len;
uint8_t *signature;
size_t signature_len;
uint8_t *attestation_cert;
size_t attestation_cert_len;
};
struct sk_sign_response {
uint8_t flags;
uint32_t counter;
uint8_t *sig_r;
size_t sig_r_len;
uint8_t *sig_s;
size_t sig_s_len;
};
struct sk_resident_key {
uint32_t alg;
size_t slot;
char *application;
struct sk_enroll_response key;
};
struct sk_option {
char *name;
char *value;
uint8_t required;
};
#define SSH_SK_VERSION_MAJOR 0x00050000 /* current API version */
#define SSH_SK_VERSION_MAJOR_MASK 0xffff0000
/* 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);
/* Enumerate all resident keys */
int sk_load_resident_keys(const char *pin, struct sk_option **options,
struct sk_resident_key ***rks, size_t *nrks);
#endif /* _SK_API_H */
