xref: /openbsd-src/usr.bin/ssh/sshkey.h (revision 9f11ffb7133c203312a01e4b986886bc88c7d74b)
1 /* $OpenBSD: sshkey.h,v 1.31 2019/01/20 22:51:37 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 #include <openssl/ec.h>
35 #include <openssl/ecdsa.h>
36 #else /* OPENSSL */
37 #define BIGNUM		void
38 #define RSA		void
39 #define DSA		void
40 #define EC_KEY		void
41 #define EC_GROUP	void
42 #define EC_POINT	void
43 #endif /* WITH_OPENSSL */
44 
45 #define SSH_RSA_MINIMUM_MODULUS_SIZE	1024
46 #define SSH_KEY_MAX_SIGN_DATA_SIZE	(1 << 20)
47 
48 struct sshbuf;
49 
50 /* Key types */
51 enum sshkey_types {
52 	KEY_RSA,
53 	KEY_DSA,
54 	KEY_ECDSA,
55 	KEY_ED25519,
56 	KEY_RSA_CERT,
57 	KEY_DSA_CERT,
58 	KEY_ECDSA_CERT,
59 	KEY_ED25519_CERT,
60 	KEY_XMSS,
61 	KEY_XMSS_CERT,
62 	KEY_UNSPEC
63 };
64 
65 /* Default fingerprint hash */
66 #define SSH_FP_HASH_DEFAULT	SSH_DIGEST_SHA256
67 
68 /* Fingerprint representation formats */
69 enum sshkey_fp_rep {
70 	SSH_FP_DEFAULT = 0,
71 	SSH_FP_HEX,
72 	SSH_FP_BASE64,
73 	SSH_FP_BUBBLEBABBLE,
74 	SSH_FP_RANDOMART
75 };
76 
77 /* Private key serialisation formats, used on the wire */
78 enum sshkey_serialize_rep {
79 	SSHKEY_SERIALIZE_DEFAULT = 0,
80 	SSHKEY_SERIALIZE_STATE = 1,
81 	SSHKEY_SERIALIZE_FULL = 2,
82 	SSHKEY_SERIALIZE_INFO = 254,
83 };
84 
85 /* key is stored in external hardware */
86 #define SSHKEY_FLAG_EXT		0x0001
87 
88 #define SSHKEY_CERT_MAX_PRINCIPALS	256
89 /* XXX opaquify? */
90 struct sshkey_cert {
91 	struct sshbuf	*certblob; /* Kept around for use on wire */
92 	u_int		 type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */
93 	u_int64_t	 serial;
94 	char		*key_id;
95 	u_int		 nprincipals;
96 	char		**principals;
97 	u_int64_t	 valid_after, valid_before;
98 	struct sshbuf	*critical;
99 	struct sshbuf	*extensions;
100 	struct sshkey	*signature_key;
101 	char		*signature_type;
102 };
103 
104 /* XXX opaquify? */
105 struct sshkey {
106 	int	 type;
107 	int	 flags;
108 	RSA	*rsa;
109 	DSA	*dsa;
110 	int	 ecdsa_nid;	/* NID of curve */
111 	EC_KEY	*ecdsa;
112 	u_char	*ed25519_sk;
113 	u_char	*ed25519_pk;
114 	char	*xmss_name;
115 	char	*xmss_filename;	/* for state file updates */
116 	void	*xmss_state;	/* depends on xmss_name, opaque */
117 	u_char	*xmss_sk;
118 	u_char	*xmss_pk;
119 	struct sshkey_cert *cert;
120 };
121 
122 #define	ED25519_SK_SZ	crypto_sign_ed25519_SECRETKEYBYTES
123 #define	ED25519_PK_SZ	crypto_sign_ed25519_PUBLICKEYBYTES
124 
125 struct sshkey	*sshkey_new(int);
126 void		 sshkey_free(struct sshkey *);
127 int		 sshkey_equal_public(const struct sshkey *,
128     const struct sshkey *);
129 int		 sshkey_equal(const struct sshkey *, const struct sshkey *);
130 char		*sshkey_fingerprint(const struct sshkey *,
131     int, enum sshkey_fp_rep);
132 int		 sshkey_fingerprint_raw(const struct sshkey *k,
133     int, u_char **retp, size_t *lenp);
134 const char	*sshkey_type(const struct sshkey *);
135 const char	*sshkey_cert_type(const struct sshkey *);
136 int		 sshkey_format_text(const struct sshkey *, struct sshbuf *);
137 int		 sshkey_write(const struct sshkey *, FILE *);
138 int		 sshkey_read(struct sshkey *, char **);
139 u_int		 sshkey_size(const struct sshkey *);
140 
141 int		 sshkey_generate(int type, u_int bits, struct sshkey **keyp);
142 int		 sshkey_from_private(const struct sshkey *, struct sshkey **);
143 int	 sshkey_type_from_name(const char *);
144 int	 sshkey_is_cert(const struct sshkey *);
145 int	 sshkey_type_is_cert(int);
146 int	 sshkey_type_plain(int);
147 int	 sshkey_to_certified(struct sshkey *);
148 int	 sshkey_drop_cert(struct sshkey *);
149 int	 sshkey_cert_copy(const struct sshkey *, struct sshkey *);
150 int	 sshkey_cert_check_authority(const struct sshkey *, int, int,
151     const char *, const char **);
152 size_t	 sshkey_format_cert_validity(const struct sshkey_cert *,
153     char *, size_t) __attribute__((__bounded__(__string__, 2, 3)));
154 int	 sshkey_check_cert_sigtype(const struct sshkey *, const char *);
155 
156 int	 sshkey_certify(struct sshkey *, struct sshkey *, const char *);
157 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */
158 typedef int sshkey_certify_signer(const struct sshkey *, u_char **, size_t *,
159     const u_char *, size_t, const char *, u_int, void *);
160 int	 sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *,
161     sshkey_certify_signer *, void *);
162 
163 int		 sshkey_ecdsa_nid_from_name(const char *);
164 int		 sshkey_curve_name_to_nid(const char *);
165 const char *	 sshkey_curve_nid_to_name(int);
166 u_int		 sshkey_curve_nid_to_bits(int);
167 int		 sshkey_ecdsa_bits_to_nid(int);
168 int		 sshkey_ecdsa_key_to_nid(EC_KEY *);
169 int		 sshkey_ec_nid_to_hash_alg(int nid);
170 int		 sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *);
171 int		 sshkey_ec_validate_private(const EC_KEY *);
172 const char	*sshkey_ssh_name(const struct sshkey *);
173 const char	*sshkey_ssh_name_plain(const struct sshkey *);
174 int		 sshkey_names_valid2(const char *, int);
175 char		*sshkey_alg_list(int, int, int, char);
176 
177 int	 sshkey_from_blob(const u_char *, size_t, struct sshkey **);
178 int	 sshkey_fromb(struct sshbuf *, struct sshkey **);
179 int	 sshkey_froms(struct sshbuf *, struct sshkey **);
180 int	 sshkey_to_blob(const struct sshkey *, u_char **, size_t *);
181 int	 sshkey_to_base64(const struct sshkey *, char **);
182 int	 sshkey_putb(const struct sshkey *, struct sshbuf *);
183 int	 sshkey_puts(const struct sshkey *, struct sshbuf *);
184 int	 sshkey_puts_opts(const struct sshkey *, struct sshbuf *,
185     enum sshkey_serialize_rep);
186 int	 sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *);
187 int	 sshkey_putb_plain(const struct sshkey *, struct sshbuf *);
188 
189 int	 sshkey_sign(const struct sshkey *, u_char **, size_t *,
190     const u_char *, size_t, const char *, u_int);
191 int	 sshkey_verify(const struct sshkey *, const u_char *, size_t,
192     const u_char *, size_t, const char *, u_int);
193 int	 sshkey_check_sigtype(const u_char *, size_t, const char *);
194 const char *sshkey_sigalg_by_name(const char *);
195 
196 /* for debug */
197 void	sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);
198 void	sshkey_dump_ec_key(const EC_KEY *);
199 
200 /* private key parsing and serialisation */
201 int	sshkey_private_serialize(const struct sshkey *key, struct sshbuf *buf);
202 int	sshkey_private_serialize_opt(const struct sshkey *key, struct sshbuf *buf,
203     enum sshkey_serialize_rep);
204 int	sshkey_private_deserialize(struct sshbuf *buf,  struct sshkey **keyp);
205 
206 /* private key file format parsing and serialisation */
207 int	sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
208     const char *passphrase, const char *comment,
209     int force_new_format, const char *new_format_cipher, int new_format_rounds);
210 int	sshkey_parse_private_fileblob(struct sshbuf *buffer,
211     const char *passphrase, struct sshkey **keyp, char **commentp);
212 int	sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
213     const char *passphrase, struct sshkey **keyp, char **commentp);
214 
215 /* XXX should be internal, but used by ssh-keygen */
216 int ssh_rsa_complete_crt_parameters(struct sshkey *, const BIGNUM *);
217 
218 /* stateful keys (e.g. XMSS) */
219 typedef void sshkey_printfn(const char *, ...) __attribute__((format(printf, 1, 2)));
220 int	 sshkey_set_filename(struct sshkey *, const char *);
221 int	 sshkey_enable_maxsign(struct sshkey *, u_int32_t);
222 u_int32_t sshkey_signatures_left(const struct sshkey *);
223 int	 sshkey_forward_state(const struct sshkey *, u_int32_t, sshkey_printfn *);
224 int	 sshkey_private_serialize_maxsign(const struct sshkey *key, struct sshbuf *buf,
225     u_int32_t maxsign, sshkey_printfn *pr);
226 
227 #ifdef SSHKEY_INTERNAL
228 int ssh_rsa_sign(const struct sshkey *key,
229     u_char **sigp, size_t *lenp, const u_char *data, size_t datalen,
230     const char *ident);
231 int ssh_rsa_verify(const struct sshkey *key,
232     const u_char *sig, size_t siglen, const u_char *data, size_t datalen,
233     const char *alg);
234 int ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
235     const u_char *data, size_t datalen, u_int compat);
236 int ssh_dss_verify(const struct sshkey *key,
237     const u_char *signature, size_t signaturelen,
238     const u_char *data, size_t datalen, u_int compat);
239 int ssh_ecdsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
240     const u_char *data, size_t datalen, u_int compat);
241 int ssh_ecdsa_verify(const struct sshkey *key,
242     const u_char *signature, size_t signaturelen,
243     const u_char *data, size_t datalen, u_int compat);
244 int ssh_ed25519_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_ed25519_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_xmss_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_xmss_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 #endif
255 
256 #ifndef WITH_OPENSSL
257 #undef RSA
258 #undef DSA
259 #undef EC_KEY
260 #undef EC_GROUP
261 #undef EC_POINT
262 #endif /* WITH_OPENSSL */
263 
264 #endif /* SSHKEY_H */
265