1/* $OpenBSD: hostfile.h,v 1.29 2021/01/26 00:51:30 djm Exp $ */
2
3/*
4 * Author: Tatu Ylonen <ylo@cs.hut.fi>
5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 *                    All rights reserved
7 *
8 * As far as I am concerned, the code I have written for this software
9 * can be used freely for any purpose.  Any derived versions of this
10 * software must be clearly marked as such, and if the derived work is
11 * incompatible with the protocol description in the RFC file, it must be
12 * called by a name other than "ssh" or "Secure Shell".
13 */
14#ifndef HOSTFILE_H
15#define HOSTFILE_H
16
17typedef enum {
18	HOST_OK, HOST_NEW, HOST_CHANGED, HOST_REVOKED, HOST_FOUND
19}       HostStatus;
20
21typedef enum {
22	MRK_ERROR, MRK_NONE, MRK_REVOKE, MRK_CA
23}	HostkeyMarker;
24
25struct hostkey_entry {
26	char *host;
27	char *file;
28	u_long line;
29	struct sshkey *key;
30	HostkeyMarker marker;
31	u_int note; /* caller-specific note/flag */
32};
33struct hostkeys {
34	struct hostkey_entry *entries;
35	u_int num_entries;
36};
37
38struct hostkeys *init_hostkeys(void);
39void	 load_hostkeys(struct hostkeys *, const char *,
40    const char *, u_int);
41void	 load_hostkeys_file(struct hostkeys *, const char *,
42    const char *, FILE *, u_int note);
43void	 free_hostkeys(struct hostkeys *);
44
45HostStatus check_key_in_hostkeys(struct hostkeys *, struct sshkey *,
46    const struct hostkey_entry **);
47int	 lookup_key_in_hostkeys_by_type(struct hostkeys *, int, int,
48    const struct hostkey_entry **);
49int	 lookup_marker_in_hostkeys(struct hostkeys *, int);
50
51int	 hostfile_read_key(char **, u_int *, struct sshkey *);
52int	 add_host_to_hostfile(const char *, const char *,
53    const struct sshkey *, int);
54
55int	 hostfile_replace_entries(const char *filename,
56    const char *host, const char *ip, struct sshkey **keys, size_t nkeys,
57    int store_hash, int quiet, int hash_alg);
58
59#define HASH_MAGIC	"|1|"
60#define HASH_DELIM	'|'
61
62#define CA_MARKER	"@cert-authority"
63#define REVOKE_MARKER	"@revoked"
64
65char	*host_hash(const char *, const char *, u_int);
66
67/*
68 * Iterate through a hostkeys file, optionally parsing keys and matching
69 * hostnames. Allows access to the raw keyfile lines to allow
70 * streaming edits to the file to take place.
71 */
72#define HKF_WANT_MATCH		(1)	/* return only matching hosts/addrs */
73#define HKF_WANT_PARSE_KEY	(1<<1)	/* need key parsed */
74
75#define HKF_STATUS_OK		0	/* Line parsed, didn't match host */
76#define HKF_STATUS_INVALID	1	/* line had parse error */
77#define HKF_STATUS_COMMENT	2	/* valid line contained no key */
78#define HKF_STATUS_MATCHED	3	/* hostname or IP matched */
79
80#define HKF_MATCH_HOST		(1)	/* hostname matched */
81#define HKF_MATCH_IP		(1<<1)	/* address matched */
82#define HKF_MATCH_HOST_HASHED	(1<<2)	/* hostname was hashed */
83#define HKF_MATCH_IP_HASHED	(1<<3)	/* address was hashed */
84/* XXX HKF_MATCH_KEY_TYPE? */
85
86/*
87 * The callback function receives this as an argument for each matching
88 * hostkey line. The callback may "steal" the 'key' field by setting it to NULL.
89 * If a parse error occurred, then "hosts" and subsequent options may be NULL.
90 */
91struct hostkey_foreach_line {
92	const char *path; /* Path of file */
93	u_long linenum;	/* Line number */
94	u_int status;	/* One of HKF_STATUS_* */
95	u_int match;	/* Zero or more of HKF_MATCH_* OR'd together */
96	char *line;	/* Entire key line; mutable by callback */
97	int marker;	/* CA/revocation markers; indicated by MRK_* value */
98	const char *hosts; /* Raw hosts text, may be hashed or list multiple */
99	const char *rawkey; /* Text of key and any comment following it */
100	int keytype;	/* Type of key; KEY_UNSPEC for invalid/comment lines */
101	struct sshkey *key; /* Key, if parsed ok and HKF_WANT_MATCH_HOST set */
102	const char *comment; /* Any comment following the key */
103	u_int note;	/* caller-specified note copied from arguments */
104};
105
106/*
107 * Callback fires for each line (or matching line if a HKF_WANT_* option
108 * is set). The foreach loop will terminate if the callback returns a non-
109 * zero exit status.
110 */
111typedef int hostkeys_foreach_fn(struct hostkey_foreach_line *l, void *ctx);
112
113/* Iterate over a hostkeys file */
114int hostkeys_foreach(const char *path,
115    hostkeys_foreach_fn *callback, void *ctx,
116    const char *host, const char *ip, u_int options, u_int note);
117int hostkeys_foreach_file(const char *path, FILE *f,
118    hostkeys_foreach_fn *callback, void *ctx,
119    const char *host, const char *ip, u_int options, u_int note);
120
121void hostfile_create_user_ssh_dir(const char *, int);
122
123#endif
124