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sshkey.h revision 1.1.1.16
      1 /* $OpenBSD: sshkey.h,v 1.46 2020/08/27 01:06:19 djm Exp $ */
      2 
      3 /*
      4  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 #ifndef SSHKEY_H
     27 #define SSHKEY_H
     28 
     29 #include <sys/types.h>
     30 
     31 #ifdef WITH_OPENSSL
     32 #include <openssl/rsa.h>
     33 #include <openssl/dsa.h>
     34 #include <openssl/ec.h>
     35 #include <openssl/ecdsa.h>
     36 #else /* OPENSSL */
     37 #define BIGNUM		void
     38 #define RSA		void
     39 #define DSA		void
     40 #define EC_KEY		void
     41 #define EC_GROUP	void
     42 #define EC_POINT	void
     43 #endif /* WITH_OPENSSL */
     44 
     45 #define SSH_RSA_MINIMUM_MODULUS_SIZE	1024
     46 #define SSH_KEY_MAX_SIGN_DATA_SIZE	(1 << 20)
     47 
     48 struct sshbuf;
     49 
     50 /* Key types */
     51 enum sshkey_types {
     52 	KEY_RSA,
     53 	KEY_DSA,
     54 	KEY_ECDSA,
     55 	KEY_ED25519,
     56 	KEY_RSA_CERT,
     57 	KEY_DSA_CERT,
     58 	KEY_ECDSA_CERT,
     59 	KEY_ED25519_CERT,
     60 	KEY_XMSS,
     61 	KEY_XMSS_CERT,
     62 	KEY_ECDSA_SK,
     63 	KEY_ECDSA_SK_CERT,
     64 	KEY_ED25519_SK,
     65 	KEY_ED25519_SK_CERT,
     66 	KEY_UNSPEC
     67 };
     68 
     69 /* Default fingerprint hash */
     70 #define SSH_FP_HASH_DEFAULT	SSH_DIGEST_SHA256
     71 
     72 /* Fingerprint representation formats */
     73 enum sshkey_fp_rep {
     74 	SSH_FP_DEFAULT = 0,
     75 	SSH_FP_HEX,
     76 	SSH_FP_BASE64,
     77 	SSH_FP_BUBBLEBABBLE,
     78 	SSH_FP_RANDOMART
     79 };
     80 
     81 /* Private key serialisation formats, used on the wire */
     82 enum sshkey_serialize_rep {
     83 	SSHKEY_SERIALIZE_DEFAULT = 0,
     84 	SSHKEY_SERIALIZE_STATE = 1,	/* only state is serialized */
     85 	SSHKEY_SERIALIZE_FULL = 2,	/* include keys for saving to disk */
     86 	SSHKEY_SERIALIZE_SHIELD = 3,	/* everything, for encrypting in ram */
     87 	SSHKEY_SERIALIZE_INFO = 254,	/* minimal information */
     88 };
     89 
     90 /* Private key disk formats */
     91 enum sshkey_private_format {
     92 	SSHKEY_PRIVATE_OPENSSH = 0,
     93 	SSHKEY_PRIVATE_PEM = 1,
     94 	SSHKEY_PRIVATE_PKCS8 = 2,
     95 };
     96 
     97 /* key is stored in external hardware */
     98 #define SSHKEY_FLAG_EXT		0x0001
     99 
    100 #define SSHKEY_CERT_MAX_PRINCIPALS	256
    101 /* XXX opaquify? */
    102 struct sshkey_cert {
    103 	struct sshbuf	*certblob; /* Kept around for use on wire */
    104 	u_int		 type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */
    105 	u_int64_t	 serial;
    106 	char		*key_id;
    107 	u_int		 nprincipals;
    108 	char		**principals;
    109 	u_int64_t	 valid_after, valid_before;
    110 	struct sshbuf	*critical;
    111 	struct sshbuf	*extensions;
    112 	struct sshkey	*signature_key;
    113 	char		*signature_type;
    114 };
    115 
    116 /* XXX opaquify? */
    117 struct sshkey {
    118 	int	 type;
    119 	int	 flags;
    120 	/* KEY_RSA */
    121 	RSA	*rsa;
    122 	/* KEY_DSA */
    123 	DSA	*dsa;
    124 	/* KEY_ECDSA and KEY_ECDSA_SK */
    125 	int	 ecdsa_nid;	/* NID of curve */
    126 	EC_KEY	*ecdsa;
    127 	/* KEY_ED25519 and KEY_ED25519_SK */
    128 	u_char	*ed25519_sk;
    129 	u_char	*ed25519_pk;
    130 	/* KEY_XMSS */
    131 	char	*xmss_name;
    132 	char	*xmss_filename;	/* for state file updates */
    133 	void	*xmss_state;	/* depends on xmss_name, opaque */
    134 	u_char	*xmss_sk;
    135 	u_char	*xmss_pk;
    136 	/* KEY_ECDSA_SK and KEY_ED25519_SK */
    137 	char	*sk_application;
    138 	uint8_t	sk_flags;
    139 	struct sshbuf *sk_key_handle;
    140 	struct sshbuf *sk_reserved;
    141 	/* Certificates */
    142 	struct sshkey_cert *cert;
    143 	/* Private key shielding */
    144 	u_char	*shielded_private;
    145 	size_t	shielded_len;
    146 	u_char	*shield_prekey;
    147 	size_t	shield_prekey_len;
    148 };
    149 
    150 #define	ED25519_SK_SZ	crypto_sign_ed25519_SECRETKEYBYTES
    151 #define	ED25519_PK_SZ	crypto_sign_ed25519_PUBLICKEYBYTES
    152 
    153 /* Additional fields contained in signature */
    154 struct sshkey_sig_details {
    155 	uint32_t sk_counter;	/* U2F signature counter */
    156 	uint8_t sk_flags;	/* U2F signature flags; see ssh-sk.h */
    157 };
    158 
    159 struct sshkey	*sshkey_new(int);
    160 void		 sshkey_free(struct sshkey *);
    161 int		 sshkey_equal_public(const struct sshkey *,
    162     const struct sshkey *);
    163 int		 sshkey_equal(const struct sshkey *, const struct sshkey *);
    164 char		*sshkey_fingerprint(const struct sshkey *,
    165     int, enum sshkey_fp_rep);
    166 int		 sshkey_fingerprint_raw(const struct sshkey *k,
    167     int, u_char **retp, size_t *lenp);
    168 const char	*sshkey_type(const struct sshkey *);
    169 const char	*sshkey_cert_type(const struct sshkey *);
    170 int		 sshkey_format_text(const struct sshkey *, struct sshbuf *);
    171 int		 sshkey_write(const struct sshkey *, FILE *);
    172 int		 sshkey_read(struct sshkey *, char **);
    173 u_int		 sshkey_size(const struct sshkey *);
    174 
    175 int		 sshkey_generate(int type, u_int bits, struct sshkey **keyp);
    176 int		 sshkey_from_private(const struct sshkey *, struct sshkey **);
    177 
    178 int		 sshkey_is_shielded(struct sshkey *);
    179 int		 sshkey_shield_private(struct sshkey *);
    180 int		 sshkey_unshield_private(struct sshkey *);
    181 
    182 int	 sshkey_type_from_name(const char *);
    183 int	 sshkey_is_cert(const struct sshkey *);
    184 int	 sshkey_is_sk(const struct sshkey *);
    185 int	 sshkey_type_is_cert(int);
    186 int	 sshkey_type_plain(int);
    187 int	 sshkey_to_certified(struct sshkey *);
    188 int	 sshkey_drop_cert(struct sshkey *);
    189 int	 sshkey_cert_copy(const struct sshkey *, struct sshkey *);
    190 int	 sshkey_cert_check_authority(const struct sshkey *, int, int,
    191     const char *, const char **);
    192 size_t	 sshkey_format_cert_validity(const struct sshkey_cert *,
    193     char *, size_t) __attribute__((__bounded__(__string__, 2, 3)));
    194 int	 sshkey_check_cert_sigtype(const struct sshkey *, const char *);
    195 
    196 int	 sshkey_certify(struct sshkey *, struct sshkey *,
    197     const char *, const char *, const char *);
    198 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */
    199 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *,
    200     const u_char *, size_t, const char *, const char *, const char *,
    201     u_int, void *);
    202 int	 sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *,
    203     const char *, const char *, sshkey_certify_signer *, void *);
    204 
    205 int		 sshkey_ecdsa_nid_from_name(const char *);
    206 int		 sshkey_curve_name_to_nid(const char *);
    207 const char *	 sshkey_curve_nid_to_name(int);
    208 u_int		 sshkey_curve_nid_to_bits(int);
    209 int		 sshkey_ecdsa_bits_to_nid(int);
    210 int		 sshkey_ecdsa_key_to_nid(EC_KEY *);
    211 int		 sshkey_ec_nid_to_hash_alg(int nid);
    212 int		 sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *);
    213 int		 sshkey_ec_validate_private(const EC_KEY *);
    214 const char	*sshkey_ssh_name(const struct sshkey *);
    215 const char	*sshkey_ssh_name_plain(const struct sshkey *);
    216 int		 sshkey_names_valid2(const char *, int);
    217 char		*sshkey_alg_list(int, int, int, char);
    218 
    219 int	 sshkey_from_blob(const u_char *, size_t, struct sshkey **);
    220 int	 sshkey_fromb(struct sshbuf *, struct sshkey **);
    221 int	 sshkey_froms(struct sshbuf *, struct sshkey **);
    222 int	 sshkey_to_blob(const struct sshkey *, u_char **, size_t *);
    223 int	 sshkey_to_base64(const struct sshkey *, char **);
    224 int	 sshkey_putb(const struct sshkey *, struct sshbuf *);
    225 int	 sshkey_puts(const struct sshkey *, struct sshbuf *);
    226 int	 sshkey_puts_opts(const struct sshkey *, struct sshbuf *,
    227     enum sshkey_serialize_rep);
    228 int	 sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *);
    229 int	 sshkey_putb_plain(const struct sshkey *, struct sshbuf *);
    230 
    231 int	 sshkey_sign(struct sshkey *, u_char **, size_t *,
    232     const u_char *, size_t, const char *, const char *, const char *, u_int);
    233 int	 sshkey_verify(const struct sshkey *, const u_char *, size_t,
    234     const u_char *, size_t, const char *, u_int, struct sshkey_sig_details **);
    235 int	 sshkey_check_sigtype(const u_char *, size_t, const char *);
    236 const char *sshkey_sigalg_by_name(const char *);
    237 int	 sshkey_get_sigtype(const u_char *, size_t, char **);
    238 
    239 /* for debug */
    240 void	sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);
    241 void	sshkey_dump_ec_key(const EC_KEY *);
    242 
    243 /* private key parsing and serialisation */
    244 int	sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf);
    245 int	sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf,
    246     enum sshkey_serialize_rep);
    247 int	sshkey_private_deserialize(struct sshbuf *buf,  struct sshkey **keyp);
    248 
    249 /* private key file format parsing and serialisation */
    250 int	sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
    251     const char *passphrase, const char *comment,
    252     int format, const char *openssh_format_cipher, int openssh_format_rounds);
    253 int	sshkey_parse_private_fileblob(struct sshbuf *buffer,
    254     const char *passphrase, struct sshkey **keyp, char **commentp);
    255 int	sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
    256     const char *passphrase, struct sshkey **keyp, char **commentp);
    257 int	sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob,
    258     int type, struct sshkey **pubkeyp);
    259 
    260 /* XXX should be internal, but used by ssh-keygen */
    261 int ssh_rsa_complete_crt_parameters(struct sshkey *, const BIGNUM *);
    262 
    263 /* stateful keys (e.g. XMSS) */
    264 typedef void sshkey_printfn(const char *, ...) __attribute__((format(printf, 1, 2)));
    265 int	 sshkey_set_filename(struct sshkey *, const char *);
    266 int	 sshkey_enable_maxsign(struct sshkey *, u_int32_t);
    267 u_int32_t sshkey_signatures_left(const struct sshkey *);
    268 int	 sshkey_forward_state(const struct sshkey *, u_int32_t, sshkey_printfn *);
    269 int	 sshkey_private_serialize_maxsign(struct sshkey *key, struct sshbuf *buf,
    270     u_int32_t maxsign, sshkey_printfn *pr);
    271 
    272 void	 sshkey_sig_details_free(struct sshkey_sig_details *);
    273 
    274 #ifdef SSHKEY_INTERNAL
    275 int ssh_rsa_sign(const struct sshkey *key,
    276     u_char **sigp, size_t *lenp, const u_char *data, size_t datalen,
    277     const char *ident);
    278 int ssh_rsa_verify(const struct sshkey *key,
    279     const u_char *sig, size_t siglen, const u_char *data, size_t datalen,
    280     const char *alg);
    281 int ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
    282     const u_char *data, size_t datalen, u_int compat);
    283 int ssh_dss_verify(const struct sshkey *key,
    284     const u_char *signature, size_t signaturelen,
    285     const u_char *data, size_t datalen, u_int compat);
    286 int ssh_ecdsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
    287     const u_char *data, size_t datalen, u_int compat);
    288 int ssh_ecdsa_verify(const struct sshkey *key,
    289     const u_char *signature, size_t signaturelen,
    290     const u_char *data, size_t datalen, u_int compat);
    291 int ssh_ecdsa_sk_verify(const struct sshkey *key,
    292     const u_char *signature, size_t signaturelen,
    293     const u_char *data, size_t datalen, u_int compat,
    294     struct sshkey_sig_details **detailsp);
    295 int ssh_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
    296     const u_char *data, size_t datalen, u_int compat);
    297 int ssh_ed25519_verify(const struct sshkey *key,
    298     const u_char *signature, size_t signaturelen,
    299     const u_char *data, size_t datalen, u_int compat);
    300 int ssh_ed25519_sk_verify(const struct sshkey *key,
    301     const u_char *signature, size_t signaturelen,
    302     const u_char *data, size_t datalen, u_int compat,
    303     struct sshkey_sig_details **detailsp);
    304 int ssh_xmss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
    305     const u_char *data, size_t datalen, u_int compat);
    306 int ssh_xmss_verify(const struct sshkey *key,
    307     const u_char *signature, size_t signaturelen,
    308     const u_char *data, size_t datalen, u_int compat);
    309 #endif
    310 
    311 #ifndef WITH_OPENSSL
    312 #undef RSA
    313 #undef DSA
    314 #undef EC_KEY
    315 #undef EC_GROUP
    316 #undef EC_POINT
    317 #endif /* WITH_OPENSSL */
    318 
    319 #endif /* SSHKEY_H */
    320