xref: /freebsd/crypto/openssh/hostfile.h (revision 19261079b74319502c6ffa1249920079f0f69a72)
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 
17 typedef enum {
18 	HOST_OK, HOST_NEW, HOST_CHANGED, HOST_REVOKED, HOST_FOUND
19 }       HostStatus;
20 
21 typedef enum {
22 	MRK_ERROR, MRK_NONE, MRK_REVOKE, MRK_CA
23 }	HostkeyMarker;
24 
25 struct 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 };
33 struct hostkeys {
34 	struct hostkey_entry *entries;
35 	u_int num_entries;
36 };
37 
38 struct hostkeys *init_hostkeys(void);
39 void	 load_hostkeys(struct hostkeys *, const char *,
40     const char *, u_int);
41 void	 load_hostkeys_file(struct hostkeys *, const char *,
42     const char *, FILE *, u_int note);
43 void	 free_hostkeys(struct hostkeys *);
44 
45 HostStatus check_key_in_hostkeys(struct hostkeys *, struct sshkey *,
46     const struct hostkey_entry **);
47 int	 lookup_key_in_hostkeys_by_type(struct hostkeys *, int, int,
48     const struct hostkey_entry **);
49 int	 lookup_marker_in_hostkeys(struct hostkeys *, int);
50 
51 int	 hostfile_read_key(char **, u_int *, struct sshkey *);
52 int	 add_host_to_hostfile(const char *, const char *,
53     const struct sshkey *, int);
54 
55 int	 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 
65 char	*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  */
91 struct 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  */
111 typedef int hostkeys_foreach_fn(struct hostkey_foreach_line *l, void *ctx);
112 
113 /* Iterate over a hostkeys file */
114 int 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);
117 int 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 
121 void hostfile_create_user_ssh_dir(const char *, int);
122 
123 #endif
124