sk_common.h

/*
 * This file is part of the SSH Library
 *
 * Copyright (c) 2025 Praneeth Sarode <praneethsarode@gmail.com>
 *
 * The SSH Library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, version 2.1 of the License.
 *
 * The SSH Library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with the SSH Library; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */
 
#ifndef SK_COMMON_H
#define SK_COMMON_H
 
#include "libssh/callbacks.h"
#include "libssh/sk_api.h"
 
#include <stdbool.h>
 
#define SK_MAX_USER_ID_LEN 64
 
#define SK_NOT_SUPPORTED_MSG                                                \
    "Security Key functionality is not supported in this build of libssh. " \
    "Please enable support by building using the WITH_FIDO2 build option."

const char *ssh_sk_err_to_string(int sk_err);

void sk_enroll_response_burn(struct sk_enroll_response *enroll_response);

void sk_enroll_response_free(struct sk_enroll_response *enroll_response);

void sk_sign_response_free(struct sk_sign_response *sign_response);

void sk_resident_key_free(struct sk_resident_key *resident_key);

void sk_options_free(struct sk_option **options);

int sk_options_validate_get(const struct sk_option **options,
                            const char **keys,
                            char ***values);

struct sk_option **sk_options_dup(const struct sk_option **options);

bool sk_callbacks_check_compatibility(
    const struct ssh_sk_callbacks_struct *callbacks);
 
/* Convenience macros for secure freeing with NULL checks and pointer reset */
#define SK_ENROLL_RESPONSE_FREE(x)      \
    do {                                \
        if ((x) != NULL) {              \
            sk_enroll_response_free(x); \
            x = NULL;                   \
        }                               \
    } while (0)
 
#define SK_SIGN_RESPONSE_FREE(x)      \
    do {                              \
        if ((x) != NULL) {            \
            sk_sign_response_free(x); \
            x = NULL;                 \
        }                             \
    } while (0)
 
#define SK_RESIDENT_KEY_FREE(x)      \
    do {                             \
        if ((x) != NULL) {           \
            sk_resident_key_free(x); \
            x = NULL;                \
        }                            \
    } while (0)
 
#define SK_OPTIONS_FREE(x)      \
    do {                        \
        if ((x) != NULL) {      \
            sk_options_free(x); \
            x = NULL;           \
        }                       \
    } while (0)
 
#endif /* SK_COMMON_H */