xref: /openssh-portable/sshkey.h (revision 7c096c45)
1 /* $OpenBSD: sshkey.h,v 1.37 2019/11/12 19:29:25 markus 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_ED25519_SK,
71 	KEY_ED25519_SK_CERT,
72 	KEY_UNSPEC
73 };
74 
75 /* Default fingerprint hash */
76 #define SSH_FP_HASH_DEFAULT	SSH_DIGEST_SHA256
77 
78 /* Fingerprint representation formats */
79 enum sshkey_fp_rep {
80 	SSH_FP_DEFAULT = 0,
81 	SSH_FP_HEX,
82 	SSH_FP_BASE64,
83 	SSH_FP_BUBBLEBABBLE,
84 	SSH_FP_RANDOMART
85 };
86 
87 /* Private key serialisation formats, used on the wire */
88 enum sshkey_serialize_rep {
89 	SSHKEY_SERIALIZE_DEFAULT = 0,
90 	SSHKEY_SERIALIZE_STATE = 1,
91 	SSHKEY_SERIALIZE_FULL = 2,
92 	SSHKEY_SERIALIZE_INFO = 254,
93 };
94 
95 /* Private key disk formats */
96 enum sshkey_private_format {
97 	SSHKEY_PRIVATE_OPENSSH = 0,
98 	SSHKEY_PRIVATE_PEM = 1,
99 	SSHKEY_PRIVATE_PKCS8 = 2,
100 };
101 
102 /* key is stored in external hardware */
103 #define SSHKEY_FLAG_EXT		0x0001
104 
105 #define SSHKEY_CERT_MAX_PRINCIPALS	256
106 /* XXX opaquify? */
107 struct sshkey_cert {
108 	struct sshbuf	*certblob; /* Kept around for use on wire */
109 	u_int		 type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */
110 	u_int64_t	 serial;
111 	char		*key_id;
112 	u_int		 nprincipals;
113 	char		**principals;
114 	u_int64_t	 valid_after, valid_before;
115 	struct sshbuf	*critical;
116 	struct sshbuf	*extensions;
117 	struct sshkey	*signature_key;
118 	char		*signature_type;
119 };
120 
121 /* XXX opaquify? */
122 struct sshkey {
123 	int	 type;
124 	int	 flags;
125 	/* KEY_RSA */
126 	RSA	*rsa;
127 	/* KEY_DSA */
128 	DSA	*dsa;
129 	/* KEY_ECDSA and KEY_ECDSA_SK */
130 	int	 ecdsa_nid;	/* NID of curve */
131 	EC_KEY	*ecdsa;
132 	/* KEY_ED25519 */
133 	u_char	*ed25519_sk;
134 	u_char	*ed25519_pk;
135 	/* KEY_XMSS */
136 	char	*xmss_name;
137 	char	*xmss_filename;	/* for state file updates */
138 	void	*xmss_state;	/* depends on xmss_name, opaque */
139 	u_char	*xmss_sk;
140 	u_char	*xmss_pk;
141 	/* KEY_ECDSA_SK */
142 	char	*sk_application;
143 	uint8_t	sk_flags;
144 	struct sshbuf *sk_key_handle;
145 	struct sshbuf *sk_reserved;
146 	/* Certificates */
147 	struct sshkey_cert *cert;
148 	/* Private key shielding */
149 	u_char	*shielded_private;
150 	size_t	shielded_len;
151 	u_char	*shield_prekey;
152 	size_t	shield_prekey_len;
153 };
154 
155 #define	ED25519_SK_SZ	crypto_sign_ed25519_SECRETKEYBYTES
156 #define	ED25519_PK_SZ	crypto_sign_ed25519_PUBLICKEYBYTES
157 
158 struct sshkey	*sshkey_new(int);
159 void		 sshkey_free(struct sshkey *);
160 int		 sshkey_equal_public(const struct sshkey *,
161     const struct sshkey *);
162 int		 sshkey_equal(const struct sshkey *, const struct sshkey *);
163 char		*sshkey_fingerprint(const struct sshkey *,
164     int, enum sshkey_fp_rep);
165 int		 sshkey_fingerprint_raw(const struct sshkey *k,
166     int, u_char **retp, size_t *lenp);
167 const char	*sshkey_type(const struct sshkey *);
168 const char	*sshkey_cert_type(const struct sshkey *);
169 int		 sshkey_format_text(const struct sshkey *, struct sshbuf *);
170 int		 sshkey_write(const struct sshkey *, FILE *);
171 int		 sshkey_read(struct sshkey *, char **);
172 u_int		 sshkey_size(const struct sshkey *);
173 
174 int		 sshkey_generate(int type, u_int bits, struct sshkey **keyp);
175 int		 sshkey_from_private(const struct sshkey *, struct sshkey **);
176 
177 int		 sshkey_is_shielded(struct sshkey *);
178 int		 sshkey_shield_private(struct sshkey *);
179 int		 sshkey_unshield_private(struct sshkey *);
180 
181 int	 sshkey_type_from_name(const char *);
182 int	 sshkey_is_cert(const struct sshkey *);
183 int	 sshkey_type_is_cert(int);
184 int	 sshkey_type_plain(int);
185 int	 sshkey_to_certified(struct sshkey *);
186 int	 sshkey_drop_cert(struct sshkey *);
187 int	 sshkey_cert_copy(const struct sshkey *, struct sshkey *);
188 int	 sshkey_cert_check_authority(const struct sshkey *, int, int,
189     const char *, const char **);
190 size_t	 sshkey_format_cert_validity(const struct sshkey_cert *,
191     char *, size_t) __attribute__((__bounded__(__string__, 2, 3)));
192 int	 sshkey_check_cert_sigtype(const struct sshkey *, const char *);
193 
194 int	 sshkey_certify(struct sshkey *, struct sshkey *,
195     const char *, const char *);
196 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */
197 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *,
198     const u_char *, size_t, const char *, const char *, u_int, void *);
199 int	 sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *,
200     const char *, sshkey_certify_signer *, void *);
201 
202 int		 sshkey_ecdsa_nid_from_name(const char *);
203 int		 sshkey_curve_name_to_nid(const char *);
204 const char *	 sshkey_curve_nid_to_name(int);
205 u_int		 sshkey_curve_nid_to_bits(int);
206 int		 sshkey_ecdsa_bits_to_nid(int);
207 int		 sshkey_ecdsa_key_to_nid(EC_KEY *);
208 int		 sshkey_ec_nid_to_hash_alg(int nid);
209 int		 sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *);
210 int		 sshkey_ec_validate_private(const EC_KEY *);
211 const char	*sshkey_ssh_name(const struct sshkey *);
212 const char	*sshkey_ssh_name_plain(const struct sshkey *);
213 int		 sshkey_names_valid2(const char *, int);
214 char		*sshkey_alg_list(int, int, int, char);
215 
216 int	 sshkey_from_blob(const u_char *, size_t, struct sshkey **);
217 int	 sshkey_fromb(struct sshbuf *, struct sshkey **);
218 int	 sshkey_froms(struct sshbuf *, struct sshkey **);
219 int	 sshkey_to_blob(const struct sshkey *, u_char **, size_t *);
220 int	 sshkey_to_base64(const struct sshkey *, char **);
221 int	 sshkey_putb(const struct sshkey *, struct sshbuf *);
222 int	 sshkey_puts(const struct sshkey *, struct sshbuf *);
223 int	 sshkey_puts_opts(const struct sshkey *, struct sshbuf *,
224     enum sshkey_serialize_rep);
225 int	 sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *);
226 int	 sshkey_putb_plain(const struct sshkey *, struct sshbuf *);
227 
228 int	 sshkey_sign(struct sshkey *, u_char **, size_t *,
229     const u_char *, size_t, const char *, const char *, u_int);
230 int	 sshkey_verify(const struct sshkey *, const u_char *, size_t,
231     const u_char *, size_t, const char *, u_int);
232 int	 sshkey_check_sigtype(const u_char *, size_t, const char *);
233 const char *sshkey_sigalg_by_name(const char *);
234 int	 sshkey_get_sigtype(const u_char *, size_t, char **);
235 
236 /* for debug */
237 void	sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);
238 void	sshkey_dump_ec_key(const EC_KEY *);
239 
240 /* private key parsing and serialisation */
241 int	sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf);
242 int	sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf,
243     enum sshkey_serialize_rep);
244 int	sshkey_private_deserialize(struct sshbuf *buf,  struct sshkey **keyp);
245 
246 /* private key file format parsing and serialisation */
247 int	sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
248     const char *passphrase, const char *comment,
249     int format, const char *openssh_format_cipher, int openssh_format_rounds);
250 int	sshkey_parse_private_fileblob(struct sshbuf *buffer,
251     const char *passphrase, struct sshkey **keyp, char **commentp);
252 int	sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
253     const char *passphrase, struct sshkey **keyp, char **commentp);
254 
255 /* XXX should be internal, but used by ssh-keygen */
256 int ssh_rsa_complete_crt_parameters(struct sshkey *, const BIGNUM *);
257 
258 /* stateful keys (e.g. XMSS) */
259 #ifdef NO_ATTRIBUTE_ON_PROTOTYPE_ARGS
260 typedef void sshkey_printfn(const char *, ...);
261 #else
262 typedef void sshkey_printfn(const char *, ...) __attribute__((format(printf, 1, 2)));
263 #endif
264 int	 sshkey_set_filename(struct sshkey *, const char *);
265 int	 sshkey_enable_maxsign(struct sshkey *, u_int32_t);
266 u_int32_t sshkey_signatures_left(const struct sshkey *);
267 int	 sshkey_forward_state(const struct sshkey *, u_int32_t, sshkey_printfn *);
268 int	 sshkey_private_serialize_maxsign(struct sshkey *key, struct sshbuf *buf,
269     u_int32_t maxsign, sshkey_printfn *pr);
270 
271 #ifdef SSHKEY_INTERNAL
272 int ssh_rsa_sign(const struct sshkey *key,
273     u_char **sigp, size_t *lenp, const u_char *data, size_t datalen,
274     const char *ident);
275 int ssh_rsa_verify(const struct sshkey *key,
276     const u_char *sig, size_t siglen, const u_char *data, size_t datalen,
277     const char *alg);
278 int ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
279     const u_char *data, size_t datalen, u_int compat);
280 int ssh_dss_verify(const struct sshkey *key,
281     const u_char *signature, size_t signaturelen,
282     const u_char *data, size_t datalen, u_int compat);
283 int ssh_ecdsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
284     const u_char *data, size_t datalen, u_int compat);
285 int ssh_ecdsa_verify(const struct sshkey *key,
286     const u_char *signature, size_t signaturelen,
287     const u_char *data, size_t datalen, u_int compat);
288 int ssh_ecdsa_sk_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_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
292     const u_char *data, size_t datalen, u_int compat);
293 int ssh_ed25519_verify(const struct sshkey *key,
294     const u_char *signature, size_t signaturelen,
295     const u_char *data, size_t datalen, u_int compat);
296 int ssh_ed25519_sk_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 int ssh_xmss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
300     const u_char *data, size_t datalen, u_int compat);
301 int ssh_xmss_verify(const struct sshkey *key,
302     const u_char *signature, size_t signaturelen,
303     const u_char *data, size_t datalen, u_int compat);
304 #endif
305 
306 #if !defined(WITH_OPENSSL)
307 # undef RSA
308 # undef DSA
309 # undef EC_KEY
310 # undef EC_GROUP
311 # undef EC_POINT
312 #elif !defined(OPENSSL_HAS_ECC)
313 # undef EC_KEY
314 # undef EC_GROUP
315 # undef EC_POINT
316 #endif
317 
318 #endif /* SSHKEY_H */
319