xref: /openssh-portable/sshkey.h (revision 482d23bc)
1 /* $OpenBSD: sshkey.h,v 1.28 2018/09/12 01:32:54 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 # else /* OPENSSL_HAS_ECC */
37 #  define EC_KEY	void
38 #  define EC_GROUP	void
39 #  define EC_POINT	void
40 # endif /* OPENSSL_HAS_ECC */
41 #else /* WITH_OPENSSL */
42 # define BIGNUM		void
43 # define RSA		void
44 # define DSA		void
45 # define EC_KEY		void
46 # define EC_GROUP	void
47 # define EC_POINT	void
48 #endif /* WITH_OPENSSL */
49 
50 #define SSH_RSA_MINIMUM_MODULUS_SIZE	1024
51 #define SSH_KEY_MAX_SIGN_DATA_SIZE	(1 << 20)
52 
53 struct sshbuf;
54 
55 /* Key types */
56 enum sshkey_types {
57 	KEY_RSA,
58 	KEY_DSA,
59 	KEY_ECDSA,
60 	KEY_ED25519,
61 	KEY_RSA_CERT,
62 	KEY_DSA_CERT,
63 	KEY_ECDSA_CERT,
64 	KEY_ED25519_CERT,
65 	KEY_XMSS,
66 	KEY_XMSS_CERT,
67 	KEY_UNSPEC
68 };
69 
70 /* Default fingerprint hash */
71 #define SSH_FP_HASH_DEFAULT	SSH_DIGEST_SHA256
72 
73 /* Fingerprint representation formats */
74 enum sshkey_fp_rep {
75 	SSH_FP_DEFAULT = 0,
76 	SSH_FP_HEX,
77 	SSH_FP_BASE64,
78 	SSH_FP_BUBBLEBABBLE,
79 	SSH_FP_RANDOMART
80 };
81 
82 /* Private key serialisation formats, used on the wire */
83 enum sshkey_serialize_rep {
84 	SSHKEY_SERIALIZE_DEFAULT = 0,
85 	SSHKEY_SERIALIZE_STATE = 1,
86 	SSHKEY_SERIALIZE_FULL = 2,
87 	SSHKEY_SERIALIZE_INFO = 254,
88 };
89 
90 /* key is stored in external hardware */
91 #define SSHKEY_FLAG_EXT		0x0001
92 
93 #define SSHKEY_CERT_MAX_PRINCIPALS	256
94 /* XXX opaquify? */
95 struct sshkey_cert {
96 	struct sshbuf	*certblob; /* Kept around for use on wire */
97 	u_int		 type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */
98 	u_int64_t	 serial;
99 	char		*key_id;
100 	u_int		 nprincipals;
101 	char		**principals;
102 	u_int64_t	 valid_after, valid_before;
103 	struct sshbuf	*critical;
104 	struct sshbuf	*extensions;
105 	struct sshkey	*signature_key;
106 	char		*signature_type;
107 };
108 
109 /* XXX opaquify? */
110 struct sshkey {
111 	int	 type;
112 	int	 flags;
113 	RSA	*rsa;
114 	DSA	*dsa;
115 	int	 ecdsa_nid;	/* NID of curve */
116 	EC_KEY	*ecdsa;
117 	u_char	*ed25519_sk;
118 	u_char	*ed25519_pk;
119 	char	*xmss_name;
120 	char	*xmss_filename;	/* for state file updates */
121 	void	*xmss_state;	/* depends on xmss_name, opaque */
122 	u_char	*xmss_sk;
123 	u_char	*xmss_pk;
124 	struct sshkey_cert *cert;
125 };
126 
127 #define	ED25519_SK_SZ	crypto_sign_ed25519_SECRETKEYBYTES
128 #define	ED25519_PK_SZ	crypto_sign_ed25519_PUBLICKEYBYTES
129 
130 struct sshkey	*sshkey_new(int);
131 struct sshkey	*sshkey_new_private(int); /* XXX garbage collect */
132 void		 sshkey_free(struct sshkey *);
133 int		 sshkey_equal_public(const struct sshkey *,
134     const struct sshkey *);
135 int		 sshkey_equal(const struct sshkey *, const struct sshkey *);
136 char		*sshkey_fingerprint(const struct sshkey *,
137     int, enum sshkey_fp_rep);
138 int		 sshkey_fingerprint_raw(const struct sshkey *k,
139     int, u_char **retp, size_t *lenp);
140 const char	*sshkey_type(const struct sshkey *);
141 const char	*sshkey_cert_type(const struct sshkey *);
142 int		 sshkey_format_text(const struct sshkey *, struct sshbuf *);
143 int		 sshkey_write(const struct sshkey *, FILE *);
144 int		 sshkey_read(struct sshkey *, char **);
145 u_int		 sshkey_size(const struct sshkey *);
146 
147 int		 sshkey_generate(int type, u_int bits, struct sshkey **keyp);
148 int		 sshkey_from_private(const struct sshkey *, struct sshkey **);
149 int	 sshkey_type_from_name(const char *);
150 int	 sshkey_is_cert(const struct sshkey *);
151 int	 sshkey_type_is_cert(int);
152 int	 sshkey_type_plain(int);
153 int	 sshkey_to_certified(struct sshkey *);
154 int	 sshkey_drop_cert(struct sshkey *);
155 int	 sshkey_cert_copy(const struct sshkey *, struct sshkey *);
156 int	 sshkey_cert_check_authority(const struct sshkey *, int, int,
157     const char *, const char **);
158 size_t	 sshkey_format_cert_validity(const struct sshkey_cert *,
159     char *, size_t) __attribute__((__bounded__(__string__, 2, 3)));
160 int	 sshkey_check_cert_sigtype(const struct sshkey *, const char *);
161 
162 int	 sshkey_certify(struct sshkey *, struct sshkey *, const char *);
163 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */
164 typedef int sshkey_certify_signer(const struct sshkey *, u_char **, size_t *,
165     const u_char *, size_t, const char *, u_int, void *);
166 int	 sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *,
167     sshkey_certify_signer *, void *);
168 
169 int		 sshkey_ecdsa_nid_from_name(const char *);
170 int		 sshkey_curve_name_to_nid(const char *);
171 const char *	 sshkey_curve_nid_to_name(int);
172 u_int		 sshkey_curve_nid_to_bits(int);
173 int		 sshkey_ecdsa_bits_to_nid(int);
174 int		 sshkey_ecdsa_key_to_nid(EC_KEY *);
175 int		 sshkey_ec_nid_to_hash_alg(int nid);
176 int		 sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *);
177 int		 sshkey_ec_validate_private(const EC_KEY *);
178 const char	*sshkey_ssh_name(const struct sshkey *);
179 const char	*sshkey_ssh_name_plain(const struct sshkey *);
180 int		 sshkey_names_valid2(const char *, int);
181 char		*sshkey_alg_list(int, int, int, char);
182 
183 int	 sshkey_from_blob(const u_char *, size_t, struct sshkey **);
184 int	 sshkey_fromb(struct sshbuf *, struct sshkey **);
185 int	 sshkey_froms(struct sshbuf *, struct sshkey **);
186 int	 sshkey_to_blob(const struct sshkey *, u_char **, size_t *);
187 int	 sshkey_to_base64(const struct sshkey *, char **);
188 int	 sshkey_putb(const struct sshkey *, struct sshbuf *);
189 int	 sshkey_puts(const struct sshkey *, struct sshbuf *);
190 int	 sshkey_puts_opts(const struct sshkey *, struct sshbuf *,
191     enum sshkey_serialize_rep);
192 int	 sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *);
193 int	 sshkey_putb_plain(const struct sshkey *, struct sshbuf *);
194 
195 int	 sshkey_sign(const struct sshkey *, u_char **, size_t *,
196     const u_char *, size_t, const char *, u_int);
197 int	 sshkey_verify(const struct sshkey *, const u_char *, size_t,
198     const u_char *, size_t, const char *, u_int);
199 int	 sshkey_check_sigtype(const u_char *, size_t, const char *);
200 const char *sshkey_sigalg_by_name(const char *);
201 
202 /* for debug */
203 void	sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);
204 void	sshkey_dump_ec_key(const EC_KEY *);
205 
206 /* private key parsing and serialisation */
207 int	sshkey_private_serialize(const struct sshkey *key, struct sshbuf *buf);
208 int	sshkey_private_serialize_opt(const struct sshkey *key, struct sshbuf *buf,
209     enum sshkey_serialize_rep);
210 int	sshkey_private_deserialize(struct sshbuf *buf,  struct sshkey **keyp);
211 
212 /* private key file format parsing and serialisation */
213 int	sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
214     const char *passphrase, const char *comment,
215     int force_new_format, const char *new_format_cipher, int new_format_rounds);
216 int	sshkey_parse_private_fileblob(struct sshbuf *buffer,
217     const char *passphrase, struct sshkey **keyp, char **commentp);
218 int	sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
219     const char *passphrase, struct sshkey **keyp, char **commentp);
220 
221 /* XXX should be internal, but used by ssh-keygen */
222 int ssh_rsa_complete_crt_parameters(struct sshkey *, const BIGNUM *);
223 
224 /* stateful keys (e.g. XMSS) */
225 #ifdef NO_ATTRIBUTE_ON_PROTOTYPE_ARGS
226 typedef void sshkey_printfn(const char *, ...);
227 #else
228 typedef void sshkey_printfn(const char *, ...) __attribute__((format(printf, 1, 2)));
229 #endif
230 int	 sshkey_set_filename(struct sshkey *, const char *);
231 int	 sshkey_enable_maxsign(struct sshkey *, u_int32_t);
232 u_int32_t sshkey_signatures_left(const struct sshkey *);
233 int	 sshkey_forward_state(const struct sshkey *, u_int32_t, sshkey_printfn *);
234 int	 sshkey_private_serialize_maxsign(const struct sshkey *key, struct sshbuf *buf,
235     u_int32_t maxsign, sshkey_printfn *pr);
236 
237 #ifdef SSHKEY_INTERNAL
238 int ssh_rsa_sign(const struct sshkey *key,
239     u_char **sigp, size_t *lenp, const u_char *data, size_t datalen,
240     const char *ident);
241 int ssh_rsa_verify(const struct sshkey *key,
242     const u_char *sig, size_t siglen, const u_char *data, size_t datalen,
243     const char *alg);
244 int ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
245     const u_char *data, size_t datalen, u_int compat);
246 int ssh_dss_verify(const struct sshkey *key,
247     const u_char *signature, size_t signaturelen,
248     const u_char *data, size_t datalen, u_int compat);
249 int ssh_ecdsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
250     const u_char *data, size_t datalen, u_int compat);
251 int ssh_ecdsa_verify(const struct sshkey *key,
252     const u_char *signature, size_t signaturelen,
253     const u_char *data, size_t datalen, u_int compat);
254 int ssh_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
255     const u_char *data, size_t datalen, u_int compat);
256 int ssh_ed25519_verify(const struct sshkey *key,
257     const u_char *signature, size_t signaturelen,
258     const u_char *data, size_t datalen, u_int compat);
259 int ssh_xmss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
260     const u_char *data, size_t datalen, u_int compat);
261 int ssh_xmss_verify(const struct sshkey *key,
262     const u_char *signature, size_t signaturelen,
263     const u_char *data, size_t datalen, u_int compat);
264 #endif
265 
266 #if !defined(WITH_OPENSSL)
267 # undef RSA
268 # undef DSA
269 # undef EC_KEY
270 # undef EC_GROUP
271 # undef EC_POINT
272 #elif !defined(OPENSSL_HAS_ECC)
273 # undef EC_KEY
274 # undef EC_GROUP
275 # undef EC_POINT
276 #endif
277 
278 #endif /* SSHKEY_H */
279