xref: /openssh-portable/sshkey.h (revision 4ba0d547)
1 /* $OpenBSD: sshkey.h,v 1.25 2018/07/03 11:39:54 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 RSA		void
43 # define DSA		void
44 # define EC_KEY		void
45 # define EC_GROUP	void
46 # define EC_POINT	void
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_UNSPEC
67 };
68 
69 /* Default fingerprint hash */
70 #define SSH_FP_HASH_DEFAULT	SSH_DIGEST_SHA256
71 
72 /* Fingerprint representation formats */
73 enum sshkey_fp_rep {
74 	SSH_FP_DEFAULT = 0,
75 	SSH_FP_HEX,
76 	SSH_FP_BASE64,
77 	SSH_FP_BUBBLEBABBLE,
78 	SSH_FP_RANDOMART
79 };
80 
81 /* Private key serialisation formats, used on the wire */
82 enum sshkey_serialize_rep {
83 	SSHKEY_SERIALIZE_DEFAULT = 0,
84 	SSHKEY_SERIALIZE_STATE = 1,
85 	SSHKEY_SERIALIZE_FULL = 2,
86 	SSHKEY_SERIALIZE_INFO = 254,
87 };
88 
89 /* key is stored in external hardware */
90 #define SSHKEY_FLAG_EXT		0x0001
91 
92 #define SSHKEY_CERT_MAX_PRINCIPALS	256
93 /* XXX opaquify? */
94 struct sshkey_cert {
95 	struct sshbuf	*certblob; /* Kept around for use on wire */
96 	u_int		 type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */
97 	u_int64_t	 serial;
98 	char		*key_id;
99 	u_int		 nprincipals;
100 	char		**principals;
101 	u_int64_t	 valid_after, valid_before;
102 	struct sshbuf	*critical;
103 	struct sshbuf	*extensions;
104 	struct sshkey	*signature_key;
105 };
106 
107 /* XXX opaquify? */
108 struct sshkey {
109 	int	 type;
110 	int	 flags;
111 	RSA	*rsa;
112 	DSA	*dsa;
113 	int	 ecdsa_nid;	/* NID of curve */
114 	EC_KEY	*ecdsa;
115 	u_char	*ed25519_sk;
116 	u_char	*ed25519_pk;
117 	char	*xmss_name;
118 	char	*xmss_filename;	/* for state file updates */
119 	void	*xmss_state;	/* depends on xmss_name, opaque */
120 	u_char	*xmss_sk;
121 	u_char	*xmss_pk;
122 	struct sshkey_cert *cert;
123 };
124 
125 #define	ED25519_SK_SZ	crypto_sign_ed25519_SECRETKEYBYTES
126 #define	ED25519_PK_SZ	crypto_sign_ed25519_PUBLICKEYBYTES
127 
128 struct sshkey	*sshkey_new(int);
129 int		 sshkey_add_private(struct sshkey *);
130 struct sshkey	*sshkey_new_private(int);
131 void		 sshkey_free(struct sshkey *);
132 int		 sshkey_demote(const struct sshkey *, 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 
161 int	 sshkey_certify(struct sshkey *, struct sshkey *, const char *);
162 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */
163 typedef int sshkey_certify_signer(const struct sshkey *, u_char **, size_t *,
164     const u_char *, size_t, const char *, u_int, void *);
165 int	 sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *,
166     sshkey_certify_signer *, void *);
167 
168 int		 sshkey_ecdsa_nid_from_name(const char *);
169 int		 sshkey_curve_name_to_nid(const char *);
170 const char *	 sshkey_curve_nid_to_name(int);
171 u_int		 sshkey_curve_nid_to_bits(int);
172 int		 sshkey_ecdsa_bits_to_nid(int);
173 int		 sshkey_ecdsa_key_to_nid(EC_KEY *);
174 int		 sshkey_ec_nid_to_hash_alg(int nid);
175 int		 sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *);
176 int		 sshkey_ec_validate_private(const EC_KEY *);
177 const char	*sshkey_ssh_name(const struct sshkey *);
178 const char	*sshkey_ssh_name_plain(const struct sshkey *);
179 int		 sshkey_names_valid2(const char *, int);
180 char		*sshkey_alg_list(int, int, int, char);
181 
182 int	 sshkey_from_blob(const u_char *, size_t, struct sshkey **);
183 int	 sshkey_fromb(struct sshbuf *, struct sshkey **);
184 int	 sshkey_froms(struct sshbuf *, struct sshkey **);
185 int	 sshkey_to_blob(const struct sshkey *, u_char **, size_t *);
186 int	 sshkey_to_base64(const struct sshkey *, char **);
187 int	 sshkey_putb(const struct sshkey *, struct sshbuf *);
188 int	 sshkey_puts(const struct sshkey *, struct sshbuf *);
189 int	 sshkey_puts_opts(const struct sshkey *, struct sshbuf *,
190     enum sshkey_serialize_rep);
191 int	 sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *);
192 int	 sshkey_putb_plain(const struct sshkey *, struct sshbuf *);
193 
194 int	 sshkey_sign(const struct sshkey *, u_char **, size_t *,
195     const u_char *, size_t, const char *, u_int);
196 int	 sshkey_verify(const struct sshkey *, const u_char *, size_t,
197     const u_char *, size_t, const char *, u_int);
198 int	 sshkey_check_sigtype(const u_char *, size_t, const char *);
199 
200 /* for debug */
201 void	sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);
202 void	sshkey_dump_ec_key(const EC_KEY *);
203 
204 /* private key parsing and serialisation */
205 int	sshkey_private_serialize(const struct sshkey *key, struct sshbuf *buf);
206 int	sshkey_private_serialize_opt(const struct sshkey *key, struct sshbuf *buf,
207     enum sshkey_serialize_rep);
208 int	sshkey_private_deserialize(struct sshbuf *buf,  struct sshkey **keyp);
209 
210 /* private key file format parsing and serialisation */
211 int	sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
212     const char *passphrase, const char *comment,
213     int force_new_format, const char *new_format_cipher, int new_format_rounds);
214 int	sshkey_parse_private_fileblob(struct sshbuf *buffer,
215     const char *passphrase, struct sshkey **keyp, char **commentp);
216 int	sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
217     const char *passphrase, struct sshkey **keyp, char **commentp);
218 
219 /* XXX should be internal, but used by ssh-keygen */
220 int ssh_rsa_generate_additional_parameters(struct sshkey *);
221 
222 /* stateful keys (e.g. XMSS) */
223 #ifdef NO_ATTRIBUTE_ON_PROTOTYPE_ARGS
224 typedef void sshkey_printfn(const char *, ...);
225 #else
226 typedef void sshkey_printfn(const char *, ...) __attribute__((format(printf, 1, 2)));
227 #endif
228 int	 sshkey_set_filename(struct sshkey *, const char *);
229 int	 sshkey_enable_maxsign(struct sshkey *, u_int32_t);
230 u_int32_t sshkey_signatures_left(const struct sshkey *);
231 int	 sshkey_forward_state(const struct sshkey *, u_int32_t, sshkey_printfn *);
232 int	 sshkey_private_serialize_maxsign(const struct sshkey *key, struct sshbuf *buf,
233     u_int32_t maxsign, sshkey_printfn *pr);
234 
235 #ifdef SSHKEY_INTERNAL
236 int ssh_rsa_sign(const struct sshkey *key,
237     u_char **sigp, size_t *lenp, const u_char *data, size_t datalen,
238     const char *ident);
239 int ssh_rsa_verify(const struct sshkey *key,
240     const u_char *sig, size_t siglen, const u_char *data, size_t datalen,
241     const char *alg);
242 int ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
243     const u_char *data, size_t datalen, u_int compat);
244 int ssh_dss_verify(const struct sshkey *key,
245     const u_char *signature, size_t signaturelen,
246     const u_char *data, size_t datalen, u_int compat);
247 int ssh_ecdsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
248     const u_char *data, size_t datalen, u_int compat);
249 int ssh_ecdsa_verify(const struct sshkey *key,
250     const u_char *signature, size_t signaturelen,
251     const u_char *data, size_t datalen, u_int compat);
252 int ssh_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
253     const u_char *data, size_t datalen, u_int compat);
254 int ssh_ed25519_verify(const struct sshkey *key,
255     const u_char *signature, size_t signaturelen,
256     const u_char *data, size_t datalen, u_int compat);
257 int ssh_xmss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
258     const u_char *data, size_t datalen, u_int compat);
259 int ssh_xmss_verify(const struct sshkey *key,
260     const u_char *signature, size_t signaturelen,
261     const u_char *data, size_t datalen, u_int compat);
262 #endif
263 
264 #if !defined(WITH_OPENSSL)
265 # undef RSA
266 # undef DSA
267 # undef EC_KEY
268 # undef EC_GROUP
269 # undef EC_POINT
270 #elif !defined(OPENSSL_HAS_ECC)
271 # undef EC_KEY
272 # undef EC_GROUP
273 # undef EC_POINT
274 #endif
275 
276 #endif /* SSHKEY_H */
277