xref: /netbsd-src/crypto/external/bsd/openssh/dist/sshkey.h (revision 782713e6c126f1866c6d9cfdee4ceb49483b5828)
1 /*	$NetBSD: sshkey.h,v 1.17 2022/10/05 22:39:36 christos Exp $	*/
2 /* $OpenBSD: sshkey.h,v 1.52 2022/09/17 10:30:45 djm Exp $ */
3 
4 /*
5  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 #ifndef SSHKEY_H
28 #define SSHKEY_H
29 
30 #include "includes.h"
31 #include <sys/types.h>
32 
33 #ifdef WITH_OPENSSL
34 #include <openssl/rsa.h>
35 #include <openssl/dsa.h>
36 #include <openssl/ec.h>
37 #include <openssl/ecdsa.h>
38 #define SSH_OPENSSL_VERSION OpenSSL_version(OPENSSL_VERSION)
39 #else /* OPENSSL */
40 #define BIGNUM		void
41 #define RSA		void
42 #define DSA		void
43 #define EC_KEY		void
44 #define EC_GROUP	void
45 #define EC_POINT	void
46 #define SSH_OPENSSL_VERSION "without OpenSSL"
47 #endif /* WITH_OPENSSL */
48 
49 #define SSH_RSA_MINIMUM_MODULUS_SIZE	1024
50 #define SSH_KEY_MAX_SIGN_DATA_SIZE	(1 << 20)
51 
52 struct sshbuf;
53 
54 /* Key types */
55 enum sshkey_types {
56 	KEY_RSA,
57 	KEY_DSA,
58 	KEY_ECDSA,
59 	KEY_ED25519,
60 	KEY_RSA_CERT,
61 	KEY_DSA_CERT,
62 	KEY_ECDSA_CERT,
63 	KEY_ED25519_CERT,
64 	KEY_XMSS,
65 	KEY_XMSS_CERT,
66 	KEY_ECDSA_SK,
67 	KEY_ECDSA_SK_CERT,
68 	KEY_ED25519_SK,
69 	KEY_ED25519_SK_CERT,
70 	KEY_UNSPEC
71 };
72 
73 /* Default fingerprint hash */
74 #define SSH_FP_HASH_DEFAULT	SSH_DIGEST_SHA256
75 
76 /* Fingerprint representation formats */
77 enum sshkey_fp_rep {
78 	SSH_FP_DEFAULT = 0,
79 	SSH_FP_HEX,
80 	SSH_FP_BASE64,
81 	SSH_FP_BUBBLEBABBLE,
82 	SSH_FP_RANDOMART
83 };
84 
85 /* Private key serialisation formats, used on the wire */
86 enum sshkey_serialize_rep {
87 	SSHKEY_SERIALIZE_DEFAULT = 0,
88 	SSHKEY_SERIALIZE_STATE = 1,	/* only state is serialized */
89 	SSHKEY_SERIALIZE_FULL = 2,	/* include keys for saving to disk */
90 	SSHKEY_SERIALIZE_SHIELD = 3,	/* everything, for encrypting in ram */
91 	SSHKEY_SERIALIZE_INFO = 254,	/* minimal information */
92 };
93 
94 /* Private key disk formats */
95 enum sshkey_private_format {
96 	SSHKEY_PRIVATE_OPENSSH = 0,
97 	SSHKEY_PRIVATE_PEM = 1,
98 	SSHKEY_PRIVATE_PKCS8 = 2,
99 };
100 
101 /* key is stored in external hardware */
102 #define SSHKEY_FLAG_EXT		0x0001
103 
104 #define SSHKEY_CERT_MAX_PRINCIPALS	256
105 /* XXX opaquify? */
106 struct sshkey_cert {
107 	struct sshbuf	*certblob; /* Kept around for use on wire */
108 	u_int		 type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */
109 	u_int64_t	 serial;
110 	char		*key_id;
111 	u_int		 nprincipals;
112 	char		**principals;
113 	u_int64_t	 valid_after, valid_before;
114 	struct sshbuf	*critical;
115 	struct sshbuf	*extensions;
116 	struct sshkey	*signature_key;
117 	char		*signature_type;
118 };
119 
120 /* XXX opaquify? */
121 struct sshkey {
122 	int	 type;
123 	int	 flags;
124 	/* KEY_RSA */
125 	RSA	*rsa;
126 	/* KEY_DSA */
127 	DSA	*dsa;
128 	/* KEY_ECDSA and KEY_ECDSA_SK */
129 	int	 ecdsa_nid;	/* NID of curve */
130 	EC_KEY	*ecdsa;
131 	/* KEY_ED25519 and KEY_ED25519_SK */
132 	u_char	*ed25519_sk;
133 	u_char	*ed25519_pk;
134 	/* KEY_XMSS */
135 	char	*xmss_name;
136 	char	*xmss_filename;	/* for state file updates */
137 	void	*xmss_state;	/* depends on xmss_name, opaque */
138 	u_char	*xmss_sk;
139 	u_char	*xmss_pk;
140 	/* KEY_ECDSA_SK and KEY_ED25519_SK */
141 	char	*sk_application;
142 	uint8_t	sk_flags;
143 	struct sshbuf *sk_key_handle;
144 	struct sshbuf *sk_reserved;
145 	/* Certificates */
146 	struct sshkey_cert *cert;
147 	/* Private key shielding */
148 	u_char	*shielded_private;
149 	size_t	shielded_len;
150 	u_char	*shield_prekey;
151 	size_t	shield_prekey_len;
152 };
153 
154 #define	ED25519_SK_SZ	crypto_sign_ed25519_SECRETKEYBYTES
155 #define	ED25519_PK_SZ	crypto_sign_ed25519_PUBLICKEYBYTES
156 
157 /* Additional fields contained in signature */
158 struct sshkey_sig_details {
159 	uint32_t sk_counter;	/* U2F signature counter */
160 	uint8_t sk_flags;	/* U2F signature flags; see ssh-sk.h */
161 };
162 
163 struct sshkey	*sshkey_new(int);
164 void		 sshkey_free(struct sshkey *);
165 int		 sshkey_equal_public(const struct sshkey *,
166     const struct sshkey *);
167 int		 sshkey_equal(const struct sshkey *, const struct sshkey *);
168 char		*sshkey_fingerprint(const struct sshkey *,
169     int, enum sshkey_fp_rep);
170 int		 sshkey_fingerprint_raw(const struct sshkey *k,
171     int, u_char **retp, size_t *lenp);
172 const char	*sshkey_type(const struct sshkey *);
173 const char	*sshkey_cert_type(const struct sshkey *);
174 int		 sshkey_format_text(const struct sshkey *, struct sshbuf *);
175 int		 sshkey_write(const struct sshkey *, FILE *);
176 int		 sshkey_read(struct sshkey *, char **);
177 u_int		 sshkey_size(const struct sshkey *);
178 
179 int		 sshkey_generate(int type, u_int bits, struct sshkey **keyp);
180 int		 sshkey_from_private(const struct sshkey *, struct sshkey **);
181 
182 int		 sshkey_is_shielded(struct sshkey *);
183 int		 sshkey_shield_private(struct sshkey *);
184 int		 sshkey_unshield_private(struct sshkey *);
185 
186 int	 sshkey_type_from_name(const char *);
187 int	 sshkey_is_cert(const struct sshkey *);
188 int	 sshkey_is_sk(const struct sshkey *);
189 int	 sshkey_type_is_cert(int);
190 int	 sshkey_type_plain(int);
191 
192 /* Returns non-zero if key name match sigalgs pattern list. (handles RSA) */
193 int	 sshkey_match_keyname_to_sigalgs(const char *, const char *);
194 
195 int	 sshkey_to_certified(struct sshkey *);
196 int	 sshkey_drop_cert(struct sshkey *);
197 int	 sshkey_cert_copy(const struct sshkey *, struct sshkey *);
198 int	 sshkey_cert_check_authority(const struct sshkey *, int, int, int,
199     uint64_t, const char *, const char **);
200 int	 sshkey_cert_check_authority_now(const struct sshkey *, int, int, int,
201     const char *, const char **);
202 int	 sshkey_cert_check_host(const struct sshkey *, const char *,
203     int , const char *, const char **);
204 size_t	 sshkey_format_cert_validity(const struct sshkey_cert *,
205     char *, size_t) __attribute__((__bounded__(__string__, 2, 3)));
206 int	 sshkey_check_cert_sigtype(const struct sshkey *, const char *);
207 
208 int	 sshkey_certify(struct sshkey *, struct sshkey *,
209     const char *, const char *, const char *);
210 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */
211 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *,
212     const u_char *, size_t, const char *, const char *, const char *,
213     u_int, void *);
214 int	 sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *,
215     const char *, const char *, sshkey_certify_signer *, void *);
216 
217 int		 sshkey_ecdsa_nid_from_name(const char *);
218 int		 sshkey_curve_name_to_nid(const char *);
219 const char *	 sshkey_curve_nid_to_name(int);
220 u_int		 sshkey_curve_nid_to_bits(int);
221 int		 sshkey_ecdsa_bits_to_nid(int);
222 int		 sshkey_ecdsa_key_to_nid(EC_KEY *);
223 int		 sshkey_ec_nid_to_hash_alg(int nid);
224 int		 sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *);
225 int		 sshkey_ec_validate_private(const EC_KEY *);
226 const char	*sshkey_ssh_name(const struct sshkey *);
227 const char	*sshkey_ssh_name_plain(const struct sshkey *);
228 int		 sshkey_names_valid2(const char *, int);
229 char		*sshkey_alg_list(int, int, int, char);
230 
231 int	 sshkey_from_blob(const u_char *, size_t, struct sshkey **);
232 int	 sshkey_fromb(struct sshbuf *, struct sshkey **);
233 int	 sshkey_froms(struct sshbuf *, struct sshkey **);
234 int	 sshkey_to_blob(const struct sshkey *, u_char **, size_t *);
235 int	 sshkey_to_base64(const struct sshkey *, char **);
236 int	 sshkey_putb(const struct sshkey *, struct sshbuf *);
237 int	 sshkey_puts(const struct sshkey *, struct sshbuf *);
238 int	 sshkey_puts_opts(const struct sshkey *, struct sshbuf *,
239     enum sshkey_serialize_rep);
240 int	 sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *);
241 int	 sshkey_putb_plain(const struct sshkey *, struct sshbuf *);
242 
243 int	 sshkey_sign(struct sshkey *, u_char **, size_t *,
244     const u_char *, size_t, const char *, const char *, const char *, u_int);
245 int	 sshkey_verify(const struct sshkey *, const u_char *, size_t,
246     const u_char *, size_t, const char *, u_int, struct sshkey_sig_details **);
247 int	 sshkey_check_sigtype(const u_char *, size_t, const char *);
248 const char *sshkey_sigalg_by_name(const char *);
249 int	 sshkey_get_sigtype(const u_char *, size_t, char **);
250 
251 /* for debug */
252 void	sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);
253 void	sshkey_dump_ec_key(const EC_KEY *);
254 
255 /* private key parsing and serialisation */
256 int	sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf);
257 int	sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf,
258     enum sshkey_serialize_rep);
259 int	sshkey_private_deserialize(struct sshbuf *buf,  struct sshkey **keyp);
260 
261 /* private key file format parsing and serialisation */
262 int	sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
263     const char *passphrase, const char *comment,
264     int format, const char *openssh_format_cipher, int openssh_format_rounds);
265 int	sshkey_parse_private_fileblob(struct sshbuf *buffer,
266     const char *passphrase, struct sshkey **keyp, char **commentp);
267 int	sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
268     const char *passphrase, struct sshkey **keyp, char **commentp);
269 int	sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob,
270     int type, struct sshkey **pubkeyp);
271 
272 int sshkey_check_rsa_length(const struct sshkey *, int);
273 /* XXX should be internal, but used by ssh-keygen */
274 int ssh_rsa_complete_crt_parameters(struct sshkey *, const BIGNUM *);
275 
276 /* stateful keys (e.g. XMSS) */
277 int	 sshkey_set_filename(struct sshkey *, const char *);
278 int	 sshkey_enable_maxsign(struct sshkey *, u_int32_t);
279 u_int32_t sshkey_signatures_left(const struct sshkey *);
280 int	 sshkey_forward_state(const struct sshkey *, u_int32_t, int);
281 int	 sshkey_private_serialize_maxsign(struct sshkey *key,
282     struct sshbuf *buf, u_int32_t maxsign, int);
283 
284 void	 sshkey_sig_details_free(struct sshkey_sig_details *);
285 
286 #ifdef SSHKEY_INTERNAL
287 int ssh_rsa_sign(const struct sshkey *key,
288     u_char **sigp, size_t *lenp, const u_char *data, size_t datalen,
289     const char *ident);
290 int ssh_rsa_verify(const struct sshkey *key,
291     const u_char *sig, size_t siglen, const u_char *data, size_t datalen,
292     const char *alg);
293 int ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
294     const u_char *data, size_t datalen, u_int compat);
295 int ssh_dss_verify(const struct sshkey *key,
296     const u_char *signature, size_t signaturelen,
297     const u_char *data, size_t datalen, u_int compat);
298 int ssh_ecdsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
299     const u_char *data, size_t datalen, u_int compat);
300 int ssh_ecdsa_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 int ssh_ecdsa_sk_verify(const struct sshkey *key,
304     const u_char *signature, size_t signaturelen,
305     const u_char *data, size_t datalen, u_int compat,
306     struct sshkey_sig_details **detailsp);
307 int ssh_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
308     const u_char *data, size_t datalen, u_int compat);
309 int ssh_ed25519_verify(const struct sshkey *key,
310     const u_char *signature, size_t signaturelen,
311     const u_char *data, size_t datalen, u_int compat);
312 int ssh_ed25519_sk_verify(const struct sshkey *key,
313     const u_char *signature, size_t signaturelen,
314     const u_char *data, size_t datalen, u_int compat,
315     struct sshkey_sig_details **detailsp);
316 int ssh_xmss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
317     const u_char *data, size_t datalen, u_int compat);
318 int ssh_xmss_verify(const struct sshkey *key,
319     const u_char *signature, size_t signaturelen,
320     const u_char *data, size_t datalen, u_int compat);
321 #endif
322 
323 #ifndef WITH_OPENSSL
324 #undef RSA
325 #undef DSA
326 #undef EC_KEY
327 #undef EC_GROUP
328 #undef EC_POINT
329 #endif /* WITH_OPENSSL */
330 
331 #endif /* SSHKEY_H */
332