xref: /openssh-portable/sshkey.h (revision 9a14c64c)
1 /* $OpenBSD: sshkey.h,v 1.36 2019/10/31 21:23:19 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 # ifdef OPENSSL_HAS_ECC
35 #  include <openssl/ec.h>
36 #  include <openssl/ecdsa.h>
37 # else /* OPENSSL_HAS_ECC */
38 #  define EC_KEY	void
39 #  define EC_GROUP	void
40 #  define EC_POINT	void
41 # endif /* OPENSSL_HAS_ECC */
42 #else /* WITH_OPENSSL */
43 # define BIGNUM		void
44 # define RSA		void
45 # define DSA		void
46 # define EC_KEY		void
47 # define EC_GROUP	void
48 # define EC_POINT	void
49 #endif /* WITH_OPENSSL */
50 
51 #define SSH_RSA_MINIMUM_MODULUS_SIZE	1024
52 #define SSH_KEY_MAX_SIGN_DATA_SIZE	(1 << 20)
53 
54 struct sshbuf;
55 
56 /* Key types */
57 enum sshkey_types {
58 	KEY_RSA,
59 	KEY_DSA,
60 	KEY_ECDSA,
61 	KEY_ED25519,
62 	KEY_RSA_CERT,
63 	KEY_DSA_CERT,
64 	KEY_ECDSA_CERT,
65 	KEY_ED25519_CERT,
66 	KEY_XMSS,
67 	KEY_XMSS_CERT,
68 	KEY_ECDSA_SK,
69 	KEY_ECDSA_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,
89 	SSHKEY_SERIALIZE_FULL = 2,
90 	SSHKEY_SERIALIZE_INFO = 254,
91 };
92 
93 /* Private key disk formats */
94 enum sshkey_private_format {
95 	SSHKEY_PRIVATE_OPENSSH = 0,
96 	SSHKEY_PRIVATE_PEM = 1,
97 	SSHKEY_PRIVATE_PKCS8 = 2,
98 };
99 
100 /* key is stored in external hardware */
101 #define SSHKEY_FLAG_EXT		0x0001
102 
103 #define SSHKEY_CERT_MAX_PRINCIPALS	256
104 /* XXX opaquify? */
105 struct sshkey_cert {
106 	struct sshbuf	*certblob; /* Kept around for use on wire */
107 	u_int		 type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */
108 	u_int64_t	 serial;
109 	char		*key_id;
110 	u_int		 nprincipals;
111 	char		**principals;
112 	u_int64_t	 valid_after, valid_before;
113 	struct sshbuf	*critical;
114 	struct sshbuf	*extensions;
115 	struct sshkey	*signature_key;
116 	char		*signature_type;
117 };
118 
119 /* XXX opaquify? */
120 struct sshkey {
121 	int	 type;
122 	int	 flags;
123 	/* KEY_RSA */
124 	RSA	*rsa;
125 	/* KEY_DSA */
126 	DSA	*dsa;
127 	/* KEY_ECDSA and KEY_ECDSA_SK */
128 	int	 ecdsa_nid;	/* NID of curve */
129 	EC_KEY	*ecdsa;
130 	/* KEY_ED25519 */
131 	u_char	*ed25519_sk;
132 	u_char	*ed25519_pk;
133 	/* KEY_XMSS */
134 	char	*xmss_name;
135 	char	*xmss_filename;	/* for state file updates */
136 	void	*xmss_state;	/* depends on xmss_name, opaque */
137 	u_char	*xmss_sk;
138 	u_char	*xmss_pk;
139 	/* KEY_ECDSA_SK */
140 	char	*sk_application;
141 	uint8_t	sk_flags;
142 	struct sshbuf *sk_key_handle;
143 	struct sshbuf *sk_reserved;
144 	/* Certificates */
145 	struct sshkey_cert *cert;
146 	/* Private key shielding */
147 	u_char	*shielded_private;
148 	size_t	shielded_len;
149 	u_char	*shield_prekey;
150 	size_t	shield_prekey_len;
151 };
152 
153 #define	ED25519_SK_SZ	crypto_sign_ed25519_SECRETKEYBYTES
154 #define	ED25519_PK_SZ	crypto_sign_ed25519_PUBLICKEYBYTES
155 
156 struct sshkey	*sshkey_new(int);
157 void		 sshkey_free(struct sshkey *);
158 int		 sshkey_equal_public(const struct sshkey *,
159     const struct sshkey *);
160 int		 sshkey_equal(const struct sshkey *, const struct sshkey *);
161 char		*sshkey_fingerprint(const struct sshkey *,
162     int, enum sshkey_fp_rep);
163 int		 sshkey_fingerprint_raw(const struct sshkey *k,
164     int, u_char **retp, size_t *lenp);
165 const char	*sshkey_type(const struct sshkey *);
166 const char	*sshkey_cert_type(const struct sshkey *);
167 int		 sshkey_format_text(const struct sshkey *, struct sshbuf *);
168 int		 sshkey_write(const struct sshkey *, FILE *);
169 int		 sshkey_read(struct sshkey *, char **);
170 u_int		 sshkey_size(const struct sshkey *);
171 
172 int		 sshkey_generate(int type, u_int bits, struct sshkey **keyp);
173 int		 sshkey_from_private(const struct sshkey *, struct sshkey **);
174 
175 int		 sshkey_is_shielded(struct sshkey *);
176 int		 sshkey_shield_private(struct sshkey *);
177 int		 sshkey_unshield_private(struct sshkey *);
178 
179 int	 sshkey_type_from_name(const char *);
180 int	 sshkey_is_cert(const struct sshkey *);
181 int	 sshkey_type_is_cert(int);
182 int	 sshkey_type_plain(int);
183 int	 sshkey_to_certified(struct sshkey *);
184 int	 sshkey_drop_cert(struct sshkey *);
185 int	 sshkey_cert_copy(const struct sshkey *, struct sshkey *);
186 int	 sshkey_cert_check_authority(const struct sshkey *, int, int,
187     const char *, const char **);
188 size_t	 sshkey_format_cert_validity(const struct sshkey_cert *,
189     char *, size_t) __attribute__((__bounded__(__string__, 2, 3)));
190 int	 sshkey_check_cert_sigtype(const struct sshkey *, const char *);
191 
192 int	 sshkey_certify(struct sshkey *, struct sshkey *,
193     const char *, const char *);
194 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */
195 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *,
196     const u_char *, size_t, const char *, const char *, u_int, void *);
197 int	 sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *,
198     const char *, sshkey_certify_signer *, void *);
199 
200 int		 sshkey_ecdsa_nid_from_name(const char *);
201 int		 sshkey_curve_name_to_nid(const char *);
202 const char *	 sshkey_curve_nid_to_name(int);
203 u_int		 sshkey_curve_nid_to_bits(int);
204 int		 sshkey_ecdsa_bits_to_nid(int);
205 int		 sshkey_ecdsa_key_to_nid(EC_KEY *);
206 int		 sshkey_ec_nid_to_hash_alg(int nid);
207 int		 sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *);
208 int		 sshkey_ec_validate_private(const EC_KEY *);
209 const char	*sshkey_ssh_name(const struct sshkey *);
210 const char	*sshkey_ssh_name_plain(const struct sshkey *);
211 int		 sshkey_names_valid2(const char *, int);
212 char		*sshkey_alg_list(int, int, int, char);
213 
214 int	 sshkey_from_blob(const u_char *, size_t, struct sshkey **);
215 int	 sshkey_fromb(struct sshbuf *, struct sshkey **);
216 int	 sshkey_froms(struct sshbuf *, struct sshkey **);
217 int	 sshkey_to_blob(const struct sshkey *, u_char **, size_t *);
218 int	 sshkey_to_base64(const struct sshkey *, char **);
219 int	 sshkey_putb(const struct sshkey *, struct sshbuf *);
220 int	 sshkey_puts(const struct sshkey *, struct sshbuf *);
221 int	 sshkey_puts_opts(const struct sshkey *, struct sshbuf *,
222     enum sshkey_serialize_rep);
223 int	 sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *);
224 int	 sshkey_putb_plain(const struct sshkey *, struct sshbuf *);
225 
226 int	 sshkey_sign(struct sshkey *, u_char **, size_t *,
227     const u_char *, size_t, const char *, const char *, u_int);
228 int	 sshkey_verify(const struct sshkey *, const u_char *, size_t,
229     const u_char *, size_t, const char *, u_int);
230 int	 sshkey_check_sigtype(const u_char *, size_t, const char *);
231 const char *sshkey_sigalg_by_name(const char *);
232 int	 sshkey_get_sigtype(const u_char *, size_t, char **);
233 
234 /* for debug */
235 void	sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);
236 void	sshkey_dump_ec_key(const EC_KEY *);
237 
238 /* private key parsing and serialisation */
239 int	sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf);
240 int	sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf,
241     enum sshkey_serialize_rep);
242 int	sshkey_private_deserialize(struct sshbuf *buf,  struct sshkey **keyp);
243 
244 /* private key file format parsing and serialisation */
245 int	sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
246     const char *passphrase, const char *comment,
247     int format, const char *openssh_format_cipher, int openssh_format_rounds);
248 int	sshkey_parse_private_fileblob(struct sshbuf *buffer,
249     const char *passphrase, struct sshkey **keyp, char **commentp);
250 int	sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
251     const char *passphrase, struct sshkey **keyp, char **commentp);
252 
253 /* XXX should be internal, but used by ssh-keygen */
254 int ssh_rsa_complete_crt_parameters(struct sshkey *, const BIGNUM *);
255 
256 /* stateful keys (e.g. XMSS) */
257 #ifdef NO_ATTRIBUTE_ON_PROTOTYPE_ARGS
258 typedef void sshkey_printfn(const char *, ...);
259 #else
260 typedef void sshkey_printfn(const char *, ...) __attribute__((format(printf, 1, 2)));
261 #endif
262 int	 sshkey_set_filename(struct sshkey *, const char *);
263 int	 sshkey_enable_maxsign(struct sshkey *, u_int32_t);
264 u_int32_t sshkey_signatures_left(const struct sshkey *);
265 int	 sshkey_forward_state(const struct sshkey *, u_int32_t, sshkey_printfn *);
266 int	 sshkey_private_serialize_maxsign(struct sshkey *key, struct sshbuf *buf,
267     u_int32_t maxsign, sshkey_printfn *pr);
268 
269 #ifdef SSHKEY_INTERNAL
270 int ssh_rsa_sign(const struct sshkey *key,
271     u_char **sigp, size_t *lenp, const u_char *data, size_t datalen,
272     const char *ident);
273 int ssh_rsa_verify(const struct sshkey *key,
274     const u_char *sig, size_t siglen, const u_char *data, size_t datalen,
275     const char *alg);
276 int ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
277     const u_char *data, size_t datalen, u_int compat);
278 int ssh_dss_verify(const struct sshkey *key,
279     const u_char *signature, size_t signaturelen,
280     const u_char *data, size_t datalen, u_int compat);
281 int ssh_ecdsa_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_ecdsa_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_sk_verify(const struct sshkey *key,
287     const u_char *signature, size_t signaturelen,
288     const u_char *data, size_t datalen, u_int compat);
289 int ssh_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
290     const u_char *data, size_t datalen, u_int compat);
291 int ssh_ed25519_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 int ssh_xmss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
295     const u_char *data, size_t datalen, u_int compat);
296 int ssh_xmss_verify(const struct sshkey *key,
297     const u_char *signature, size_t signaturelen,
298     const u_char *data, size_t datalen, u_int compat);
299 #endif
300 
301 #if !defined(WITH_OPENSSL)
302 # undef RSA
303 # undef DSA
304 # undef EC_KEY
305 # undef EC_GROUP
306 # undef EC_POINT
307 #elif !defined(OPENSSL_HAS_ECC)
308 # undef EC_KEY
309 # undef EC_GROUP
310 # undef EC_POINT
311 #endif
312 
313 #endif /* SSHKEY_H */
314