xref: /openssh-portable/sshkey.h (revision eb0d8e70)
1 /* $OpenBSD: sshkey.h,v 1.33 2019/07/15 13:16:29 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_UNSPEC
69 };
70 
71 /* Default fingerprint hash */
72 #define SSH_FP_HASH_DEFAULT	SSH_DIGEST_SHA256
73 
74 /* Fingerprint representation formats */
75 enum sshkey_fp_rep {
76 	SSH_FP_DEFAULT = 0,
77 	SSH_FP_HEX,
78 	SSH_FP_BASE64,
79 	SSH_FP_BUBBLEBABBLE,
80 	SSH_FP_RANDOMART
81 };
82 
83 /* Private key serialisation formats, used on the wire */
84 enum sshkey_serialize_rep {
85 	SSHKEY_SERIALIZE_DEFAULT = 0,
86 	SSHKEY_SERIALIZE_STATE = 1,
87 	SSHKEY_SERIALIZE_FULL = 2,
88 	SSHKEY_SERIALIZE_INFO = 254,
89 };
90 
91 /* Private key disk formats */
92 enum sshkey_private_format {
93 	SSHKEY_PRIVATE_OPENSSH = 0,
94 	SSHKEY_PRIVATE_PEM = 1,
95 	SSHKEY_PRIVATE_PKCS8 = 2,
96 };
97 
98 /* key is stored in external hardware */
99 #define SSHKEY_FLAG_EXT		0x0001
100 
101 #define SSHKEY_CERT_MAX_PRINCIPALS	256
102 /* XXX opaquify? */
103 struct sshkey_cert {
104 	struct sshbuf	*certblob; /* Kept around for use on wire */
105 	u_int		 type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */
106 	u_int64_t	 serial;
107 	char		*key_id;
108 	u_int		 nprincipals;
109 	char		**principals;
110 	u_int64_t	 valid_after, valid_before;
111 	struct sshbuf	*critical;
112 	struct sshbuf	*extensions;
113 	struct sshkey	*signature_key;
114 	char		*signature_type;
115 };
116 
117 /* XXX opaquify? */
118 struct sshkey {
119 	int	 type;
120 	int	 flags;
121 	RSA	*rsa;
122 	DSA	*dsa;
123 	int	 ecdsa_nid;	/* NID of curve */
124 	EC_KEY	*ecdsa;
125 	u_char	*ed25519_sk;
126 	u_char	*ed25519_pk;
127 	char	*xmss_name;
128 	char	*xmss_filename;	/* for state file updates */
129 	void	*xmss_state;	/* depends on xmss_name, opaque */
130 	u_char	*xmss_sk;
131 	u_char	*xmss_pk;
132 	struct sshkey_cert *cert;
133 	u_char	*shielded_private;
134 	size_t	shielded_len;
135 	u_char	*shield_prekey;
136 	size_t	shield_prekey_len;
137 };
138 
139 #define	ED25519_SK_SZ	crypto_sign_ed25519_SECRETKEYBYTES
140 #define	ED25519_PK_SZ	crypto_sign_ed25519_PUBLICKEYBYTES
141 
142 struct sshkey	*sshkey_new(int);
143 void		 sshkey_free(struct sshkey *);
144 int		 sshkey_equal_public(const struct sshkey *,
145     const struct sshkey *);
146 int		 sshkey_equal(const struct sshkey *, const struct sshkey *);
147 char		*sshkey_fingerprint(const struct sshkey *,
148     int, enum sshkey_fp_rep);
149 int		 sshkey_fingerprint_raw(const struct sshkey *k,
150     int, u_char **retp, size_t *lenp);
151 const char	*sshkey_type(const struct sshkey *);
152 const char	*sshkey_cert_type(const struct sshkey *);
153 int		 sshkey_format_text(const struct sshkey *, struct sshbuf *);
154 int		 sshkey_write(const struct sshkey *, FILE *);
155 int		 sshkey_read(struct sshkey *, char **);
156 u_int		 sshkey_size(const struct sshkey *);
157 
158 int		 sshkey_generate(int type, u_int bits, struct sshkey **keyp);
159 int		 sshkey_from_private(const struct sshkey *, struct sshkey **);
160 
161 int		 sshkey_is_shielded(struct sshkey *);
162 int		 sshkey_shield_private(struct sshkey *);
163 int		 sshkey_unshield_private(struct sshkey *);
164 
165 int	 sshkey_type_from_name(const char *);
166 int	 sshkey_is_cert(const struct sshkey *);
167 int	 sshkey_type_is_cert(int);
168 int	 sshkey_type_plain(int);
169 int	 sshkey_to_certified(struct sshkey *);
170 int	 sshkey_drop_cert(struct sshkey *);
171 int	 sshkey_cert_copy(const struct sshkey *, struct sshkey *);
172 int	 sshkey_cert_check_authority(const struct sshkey *, int, int,
173     const char *, const char **);
174 size_t	 sshkey_format_cert_validity(const struct sshkey_cert *,
175     char *, size_t) __attribute__((__bounded__(__string__, 2, 3)));
176 int	 sshkey_check_cert_sigtype(const struct sshkey *, const char *);
177 
178 int	 sshkey_certify(struct sshkey *, struct sshkey *, const char *);
179 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */
180 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *,
181     const u_char *, size_t, const char *, u_int, void *);
182 int	 sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *,
183     sshkey_certify_signer *, void *);
184 
185 int		 sshkey_ecdsa_nid_from_name(const char *);
186 int		 sshkey_curve_name_to_nid(const char *);
187 const char *	 sshkey_curve_nid_to_name(int);
188 u_int		 sshkey_curve_nid_to_bits(int);
189 int		 sshkey_ecdsa_bits_to_nid(int);
190 int		 sshkey_ecdsa_key_to_nid(EC_KEY *);
191 int		 sshkey_ec_nid_to_hash_alg(int nid);
192 int		 sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *);
193 int		 sshkey_ec_validate_private(const EC_KEY *);
194 const char	*sshkey_ssh_name(const struct sshkey *);
195 const char	*sshkey_ssh_name_plain(const struct sshkey *);
196 int		 sshkey_names_valid2(const char *, int);
197 char		*sshkey_alg_list(int, int, int, char);
198 
199 int	 sshkey_from_blob(const u_char *, size_t, struct sshkey **);
200 int	 sshkey_fromb(struct sshbuf *, struct sshkey **);
201 int	 sshkey_froms(struct sshbuf *, struct sshkey **);
202 int	 sshkey_to_blob(const struct sshkey *, u_char **, size_t *);
203 int	 sshkey_to_base64(const struct sshkey *, char **);
204 int	 sshkey_putb(const struct sshkey *, struct sshbuf *);
205 int	 sshkey_puts(const struct sshkey *, struct sshbuf *);
206 int	 sshkey_puts_opts(const struct sshkey *, struct sshbuf *,
207     enum sshkey_serialize_rep);
208 int	 sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *);
209 int	 sshkey_putb_plain(const struct sshkey *, struct sshbuf *);
210 
211 int	 sshkey_sign(struct sshkey *, u_char **, size_t *,
212     const u_char *, size_t, const char *, u_int);
213 int	 sshkey_verify(const struct sshkey *, const u_char *, size_t,
214     const u_char *, size_t, const char *, u_int);
215 int	 sshkey_check_sigtype(const u_char *, size_t, const char *);
216 const char *sshkey_sigalg_by_name(const char *);
217 
218 /* for debug */
219 void	sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);
220 void	sshkey_dump_ec_key(const EC_KEY *);
221 
222 /* private key parsing and serialisation */
223 int	sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf);
224 int	sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf,
225     enum sshkey_serialize_rep);
226 int	sshkey_private_deserialize(struct sshbuf *buf,  struct sshkey **keyp);
227 
228 /* private key file format parsing and serialisation */
229 int	sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
230     const char *passphrase, const char *comment,
231     int format, const char *openssh_format_cipher, int openssh_format_rounds);
232 int	sshkey_parse_private_fileblob(struct sshbuf *buffer,
233     const char *passphrase, struct sshkey **keyp, char **commentp);
234 int	sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
235     const char *passphrase, struct sshkey **keyp, char **commentp);
236 
237 /* XXX should be internal, but used by ssh-keygen */
238 int ssh_rsa_complete_crt_parameters(struct sshkey *, const BIGNUM *);
239 
240 /* stateful keys (e.g. XMSS) */
241 #ifdef NO_ATTRIBUTE_ON_PROTOTYPE_ARGS
242 typedef void sshkey_printfn(const char *, ...);
243 #else
244 typedef void sshkey_printfn(const char *, ...) __attribute__((format(printf, 1, 2)));
245 #endif
246 int	 sshkey_set_filename(struct sshkey *, const char *);
247 int	 sshkey_enable_maxsign(struct sshkey *, u_int32_t);
248 u_int32_t sshkey_signatures_left(const struct sshkey *);
249 int	 sshkey_forward_state(const struct sshkey *, u_int32_t, sshkey_printfn *);
250 int	 sshkey_private_serialize_maxsign(struct sshkey *key, struct sshbuf *buf,
251     u_int32_t maxsign, sshkey_printfn *pr);
252 
253 #ifdef SSHKEY_INTERNAL
254 int ssh_rsa_sign(const struct sshkey *key,
255     u_char **sigp, size_t *lenp, const u_char *data, size_t datalen,
256     const char *ident);
257 int ssh_rsa_verify(const struct sshkey *key,
258     const u_char *sig, size_t siglen, const u_char *data, size_t datalen,
259     const char *alg);
260 int ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
261     const u_char *data, size_t datalen, u_int compat);
262 int ssh_dss_verify(const struct sshkey *key,
263     const u_char *signature, size_t signaturelen,
264     const u_char *data, size_t datalen, u_int compat);
265 int ssh_ecdsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
266     const u_char *data, size_t datalen, u_int compat);
267 int ssh_ecdsa_verify(const struct sshkey *key,
268     const u_char *signature, size_t signaturelen,
269     const u_char *data, size_t datalen, u_int compat);
270 int ssh_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
271     const u_char *data, size_t datalen, u_int compat);
272 int ssh_ed25519_verify(const struct sshkey *key,
273     const u_char *signature, size_t signaturelen,
274     const u_char *data, size_t datalen, u_int compat);
275 int ssh_xmss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
276     const u_char *data, size_t datalen, u_int compat);
277 int ssh_xmss_verify(const struct sshkey *key,
278     const u_char *signature, size_t signaturelen,
279     const u_char *data, size_t datalen, u_int compat);
280 #endif
281 
282 #if !defined(WITH_OPENSSL)
283 # undef RSA
284 # undef DSA
285 # undef EC_KEY
286 # undef EC_GROUP
287 # undef EC_POINT
288 #elif !defined(OPENSSL_HAS_ECC)
289 # undef EC_KEY
290 # undef EC_GROUP
291 # undef EC_POINT
292 #endif
293 
294 #endif /* SSHKEY_H */
295