api/latest/sshkey_8h_source.html

/* $OpenBSD: sshkey.h,v 1.49 2021/01/26 00:49:30 djm Exp $ */


/*

 * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef SSHKEY_H

#define SSHKEY_H


#include <sys/types.h>


#ifdef WITH_OPENSSL

#include <openssl/rsa.h>

#include <openssl/dsa.h>

# ifdef OPENSSL_HAS_ECC

#  include <openssl/ec.h>

#  include <openssl/ecdsa.h>

# else /* OPENSSL_HAS_ECC */

#  define EC_KEY    void

#  define EC_GROUP  void

#  define EC_POINT  void

# endif /* OPENSSL_HAS_ECC */

#define SSH_OPENSSL_VERSION OpenSSL_version(OPENSSL_VERSION)

#else /* WITH_OPENSSL */

# define BIGNUM     void

# define RSA        void

# define DSA        void

# define EC_KEY     void

# define EC_GROUP   void

# define EC_POINT   void

#define SSH_OPENSSL_VERSION "without OpenSSL"

#endif /* WITH_OPENSSL */


#define SSH_RSA_MINIMUM_MODULUS_SIZE    1024

#define SSH_KEY_MAX_SIGN_DATA_SIZE  (1 << 20)


struct sshbuf;


/* Key types */

enum sshkey_types {

    KEY_RSA,

    KEY_DSA,

    KEY_ECDSA,

    KEY_ED25519,

    KEY_RSA_CERT,

    KEY_DSA_CERT,

    KEY_ECDSA_CERT,

    KEY_ED25519_CERT,

    KEY_XMSS,

    KEY_XMSS_CERT,

    KEY_ECDSA_SK,

    KEY_ECDSA_SK_CERT,

    KEY_ED25519_SK,

    KEY_ED25519_SK_CERT,

    KEY_NULL,

    KEY_UNSPEC

};


/* Default fingerprint hash */

#define SSH_FP_HASH_DEFAULT SSH_DIGEST_SHA256


/* Fingerprint representation formats */

enum sshkey_fp_rep {

    SSH_FP_DEFAULT = 0,

    SSH_FP_HEX,

    SSH_FP_BASE64,

    SSH_FP_BUBBLEBABBLE,

    SSH_FP_RANDOMART

};


/* Private key serialisation formats, used on the wire */

enum sshkey_serialize_rep {

    SSHKEY_SERIALIZE_DEFAULT = 0,

    SSHKEY_SERIALIZE_STATE = 1, /* only state is serialized */

    SSHKEY_SERIALIZE_FULL = 2,  /* include keys for saving to disk */

    SSHKEY_SERIALIZE_SHIELD = 3,    /* everything, for encrypting in ram */

    SSHKEY_SERIALIZE_INFO = 254,    /* minimal information */

};


/* Private key disk formats */

enum sshkey_private_format {

    SSHKEY_PRIVATE_OPENSSH = 0,

    SSHKEY_PRIVATE_PEM = 1,

    SSHKEY_PRIVATE_PKCS8 = 2,

};


/* key is stored in external hardware */

#define SSHKEY_FLAG_EXT     0x0001


#define SSHKEY_CERT_MAX_PRINCIPALS  256

/* XXX opaquify? */

struct sshkey_cert {

    struct sshbuf   *certblob; /* Kept around for use on wire */

    u_int        type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */

    u_int64_t    serial;

    char        *key_id;

    u_int        nprincipals;

    char        **principals;

    u_int64_t    valid_after, valid_before;

    struct sshbuf   *critical;

    struct sshbuf   *extensions;

    struct sshkey   *signature_key;

    char        *signature_type;

};


/* XXX opaquify? */

struct sshkey {

    int  type;

    int  flags;

    /* KEY_RSA */

    RSA *rsa;

    /* KEY_DSA */

    DSA *dsa;

    /* KEY_ECDSA and KEY_ECDSA_SK */

    int  ecdsa_nid; /* NID of curve */

    EC_KEY  *ecdsa;

    /* KEY_ED25519 and KEY_ED25519_SK */

    u_char  *ed25519_sk;

    u_char  *ed25519_pk;

    /* KEY_XMSS */

    char    *xmss_name;

    char    *xmss_filename; /* for state file updates */

    void    *xmss_state;    /* depends on xmss_name, opaque */

    u_char  *xmss_sk;

    u_char  *xmss_pk;

    /* KEY_ECDSA_SK and KEY_ED25519_SK */

    char    *sk_application;

    uint8_t sk_flags;

    struct sshbuf *sk_key_handle;

    struct sshbuf *sk_reserved;

    /* Certificates */

    struct sshkey_cert *cert;

    /* Private key shielding */

    u_char  *shielded_private;

    size_t  shielded_len;

    u_char  *shield_prekey;

    size_t  shield_prekey_len;

};


#define ED25519_SK_SZ   crypto_sign_ed25519_SECRETKEYBYTES

#define ED25519_PK_SZ   crypto_sign_ed25519_PUBLICKEYBYTES


/* Additional fields contained in signature */

struct sshkey_sig_details {

    uint32_t sk_counter;    /* U2F signature counter */

    uint8_t sk_flags;   /* U2F signature flags; see ssh-sk.h */

};


struct sshkey   *sshkey_new(int);

void         sshkey_free(struct sshkey *);

int      sshkey_equal_public(const struct sshkey *,

    const struct sshkey *);

int      sshkey_equal(const struct sshkey *, const struct sshkey *);

char        *sshkey_fingerprint(const struct sshkey *,

    int, enum sshkey_fp_rep);

int      sshkey_fingerprint_raw(const struct sshkey *k,

    int, u_char **retp, size_t *lenp);

const char  *sshkey_type(const struct sshkey *);

const char  *sshkey_cert_type(const struct sshkey *);

int      sshkey_format_text(const struct sshkey *, struct sshbuf *);

int      sshkey_write(const struct sshkey *, FILE *);

int      sshkey_read(struct sshkey *, char **);

u_int        sshkey_size(const struct sshkey *);


int      sshkey_generate(int type, u_int bits, struct sshkey **keyp);

int      sshkey_from_private(const struct sshkey *, struct sshkey **);


int      sshkey_is_shielded(struct sshkey *);

int      sshkey_shield_private(struct sshkey *);

int      sshkey_unshield_private(struct sshkey *);


int  sshkey_type_from_name(const char *);

int  sshkey_is_private(const struct sshkey *);

int  sshkey_is_cert(const struct sshkey *);

int  sshkey_is_sk(const struct sshkey *);

int  sshkey_type_is_cert(int);

int  sshkey_type_plain(int);

int  sshkey_to_certified(struct sshkey *);

int  sshkey_drop_cert(struct sshkey *);

int  sshkey_cert_copy(const struct sshkey *, struct sshkey *);

int  sshkey_cert_check_authority(const struct sshkey *, int, int, int,

    const char *, const char **);

int  sshkey_cert_check_host(const struct sshkey *, const char *,

    int , const char *, const char **);

size_t   sshkey_format_cert_validity(const struct sshkey_cert *,

    char *, size_t) __attribute__((__bounded__(__string__, 2, 3)));

int  sshkey_check_cert_sigtype(const struct sshkey *, const char *);


int  sshkey_certify(struct sshkey *, struct sshkey *,

    const char *, const char *, const char *);

/* Variant allowing use of a custom signature function (e.g. for ssh-agent) */

typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *,

    const u_char *, size_t, const char *, const char *, const char *,

    u_int, void *);

int  sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *,

    const char *, const char *, sshkey_certify_signer *, void *);


int      sshkey_ecdsa_nid_from_name(const char *);

int      sshkey_curve_name_to_nid(const char *);

const char *     sshkey_curve_nid_to_name(int);

u_int        sshkey_curve_nid_to_bits(int);

int      sshkey_ecdsa_bits_to_nid(int);

int      sshkey_ecdsa_key_to_nid(EC_KEY *);

int      sshkey_ec_nid_to_hash_alg(int nid);

int      sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *);

int      sshkey_ec_validate_private(const EC_KEY *);

const char  *sshkey_ssh_name(const struct sshkey *);

const char  *sshkey_ssh_name_plain(const struct sshkey *);

int      sshkey_names_valid2(const char *, int);

char        *sshkey_alg_list(int, int, int, char);

int      sshkey_calculate_signature(EVP_PKEY*, int, u_char **,

    int *, const u_char *, size_t);

int      sshkey_verify_signature(EVP_PKEY *, int, const u_char *,

    size_t, u_char *, int);


int  sshkey_from_blob(const u_char *, size_t, struct sshkey **);

int  sshkey_fromb(struct sshbuf *, struct sshkey **);

int  sshkey_froms(struct sshbuf *, struct sshkey **);

int  sshkey_to_blob(const struct sshkey *, u_char **, size_t *);

int  sshkey_to_base64(const struct sshkey *, char **);

int  sshkey_putb(const struct sshkey *, struct sshbuf *);

int  sshkey_puts(const struct sshkey *, struct sshbuf *);

int  sshkey_puts_opts(const struct sshkey *, struct sshbuf *,

    enum sshkey_serialize_rep);

int  sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *);

int  sshkey_putb_plain(const struct sshkey *, struct sshbuf *);


int  sshkey_sign(struct sshkey *, u_char **, size_t *,

    const u_char *, size_t, const char *, const char *, const char *, u_int);

int  sshkey_verify(const struct sshkey *, const u_char *, size_t,

    const u_char *, size_t, const char *, u_int, struct sshkey_sig_details **);

int  sshkey_check_sigtype(const u_char *, size_t, const char *);

const char *sshkey_sigalg_by_name(const char *);

int  sshkey_get_sigtype(const u_char *, size_t, char **);


/* for debug */

void    sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);

void    sshkey_dump_ec_key(const EC_KEY *);


/* private key parsing and serialisation */

int sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf);

int sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf,

    enum sshkey_serialize_rep);

int sshkey_private_deserialize(struct sshbuf *buf,  struct sshkey **keyp);


/* private key file format parsing and serialisation */

int sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,

    const char *passphrase, const char *comment,

    int format, const char *openssh_format_cipher, int openssh_format_rounds);

int sshkey_parse_private_fileblob(struct sshbuf *buffer,

    const char *passphrase, struct sshkey **keyp, char **commentp);

int sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,

    const char *passphrase, struct sshkey **keyp, char **commentp);

int sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob,

    int type, struct sshkey **pubkeyp);


/* XXX should be internal, but used by ssh-keygen */

int ssh_rsa_complete_crt_parameters(struct sshkey *, const BIGNUM *);


/* stateful keys (e.g. XMSS) */

int  sshkey_set_filename(struct sshkey *, const char *);

int  sshkey_enable_maxsign(struct sshkey *, u_int32_t);

u_int32_t sshkey_signatures_left(const struct sshkey *);

int  sshkey_forward_state(const struct sshkey *, u_int32_t, int);

int  sshkey_private_serialize_maxsign(struct sshkey *key,

    struct sshbuf *buf, u_int32_t maxsign, int);


void     sshkey_sig_details_free(struct sshkey_sig_details *);


#ifdef SSHKEY_INTERNAL

int ssh_rsa_sign(const struct sshkey *key,

    u_char **sigp, size_t *lenp, const u_char *data, size_t datalen,

    const char *ident);

int ssh_rsa_verify(const struct sshkey *key,

    const u_char *sig, size_t siglen, const u_char *data, size_t datalen,

    const char *alg);

int ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,

    const u_char *data, size_t datalen, u_int compat);

int ssh_dss_verify(const struct sshkey *key,

    const u_char *signature, size_t signaturelen,

    const u_char *data, size_t datalen, u_int compat);

int ssh_ecdsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,

    const u_char *data, size_t datalen, u_int compat);

int ssh_ecdsa_verify(const struct sshkey *key,

    const u_char *signature, size_t signaturelen,

    const u_char *data, size_t datalen, u_int compat);

int ssh_ecdsa_sk_verify(const struct sshkey *key,

    const u_char *signature, size_t signaturelen,

    const u_char *data, size_t datalen, u_int compat,

    struct sshkey_sig_details **detailsp);

int ssh_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,

    const u_char *data, size_t datalen, u_int compat);

int ssh_ed25519_verify(const struct sshkey *key,

    const u_char *signature, size_t signaturelen,

    const u_char *data, size_t datalen, u_int compat);

int ssh_ed25519_sk_verify(const struct sshkey *key,

    const u_char *signature, size_t signaturelen,

    const u_char *data, size_t datalen, u_int compat,

    struct sshkey_sig_details **detailsp);

int ssh_xmss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,

    const u_char *data, size_t datalen, u_int compat);

int ssh_xmss_verify(const struct sshkey *key,

    const u_char *signature, size_t signaturelen,

    const u_char *data, size_t datalen, u_int compat);

#endif


#if !defined(WITH_OPENSSL)

# undef RSA

# undef DSA

# undef EC_KEY

# undef EC_GROUP

# undef EC_POINT

#elif !defined(OPENSSL_HAS_ECC)

# undef EC_KEY

# undef EC_GROUP

# undef EC_POINT

#endif


#endif /* SSHKEY_H */