1 /*        $NetBSD: hostfile.h,v 1.11 2021/03/05 17:47:16 christos Exp $         */
2 /* $OpenBSD: hostfile.h,v 1.29 2021/01/26 00:51:30 djm Exp $ */
3 
4 /*
5  * Author: Tatu Ylonen <ylo@cs.hut.fi>
6  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
7  *                    All rights reserved
8  *
9  * As far as I am concerned, the code I have written for this software
10  * can be used freely for any purpose.  Any derived versions of this
11  * software must be clearly marked as such, and if the derived work is
12  * incompatible with the protocol description in the RFC file, it must be
13  * called by a name other than "ssh" or "Secure Shell".
14  */
15 #ifndef HOSTFILE_H
16 #define HOSTFILE_H
17 
18 typedef enum {
19           HOST_OK, HOST_NEW, HOST_CHANGED, HOST_REVOKED, HOST_FOUND
20 }       HostStatus;
21 
22 typedef enum {
23           MRK_ERROR, MRK_NONE, MRK_REVOKE, MRK_CA
24 }         HostkeyMarker;
25 
26 struct hostkey_entry {
27           char *host;
28           char *file;
29           u_long line;
30           struct sshkey *key;
31           HostkeyMarker marker;
32           u_int note; /* caller-specific note/flag */
33 };
34 struct hostkeys {
35           struct hostkey_entry *entries;
36           u_int num_entries;
37 };
38 
39 struct hostkeys *init_hostkeys(void);
40 void       load_hostkeys(struct hostkeys *, const char *,
41     const char *, u_int);
42 void       load_hostkeys_file(struct hostkeys *, const char *,
43     const char *, FILE *, u_int note);
44 void       free_hostkeys(struct hostkeys *);
45 
46 HostStatus check_key_in_hostkeys(struct hostkeys *, struct sshkey *,
47     const struct hostkey_entry **);
48 int        lookup_key_in_hostkeys_by_type(struct hostkeys *, int, int,
49     const struct hostkey_entry **);
50 int        lookup_marker_in_hostkeys(struct hostkeys *, int);
51 
52 int        hostfile_read_key(char **, u_int *, struct sshkey *);
53 int        add_host_to_hostfile(const char *, const char *,
54     const struct sshkey *, int);
55 
56 int        hostfile_replace_entries(const char *filename,
57     const char *host, const char *ip, struct sshkey **keys, size_t nkeys,
58     int store_hash, int quiet, int hash_alg);
59 
60 #define HASH_MAGIC  "|1|"
61 #define HASH_DELIM  '|'
62 
63 #define CA_MARKER   "@cert-authority"
64 #define REVOKE_MARKER         "@revoked"
65 
66 char      *host_hash(const char *, const char *, u_int);
67 
68 /*
69  * Iterate through a hostkeys file, optionally parsing keys and matching
70  * hostnames. Allows access to the raw keyfile lines to allow
71  * streaming edits to the file to take place.
72  */
73 #define HKF_WANT_MATCH                  (1)       /* return only matching hosts/addrs */
74 #define HKF_WANT_PARSE_KEY    (1<<1)    /* need key parsed */
75 
76 #define HKF_STATUS_OK                   0         /* Line parsed, didn't match host */
77 #define HKF_STATUS_INVALID    1         /* line had parse error */
78 #define HKF_STATUS_COMMENT    2         /* valid line contained no key */
79 #define HKF_STATUS_MATCHED    3         /* hostname or IP matched */
80 
81 #define HKF_MATCH_HOST                  (1)       /* hostname matched */
82 #define HKF_MATCH_IP                    (1<<1)    /* address matched */
83 #define HKF_MATCH_HOST_HASHED (1<<2)    /* hostname was hashed */
84 #define HKF_MATCH_IP_HASHED   (1<<3)    /* address was hashed */
85 /* XXX HKF_MATCH_KEY_TYPE? */
86 
87 /*
88  * The callback function receives this as an argument for each matching
89  * hostkey line. The callback may "steal" the 'key' field by setting it to NULL.
90  * If a parse error occurred, then "hosts" and subsequent options may be NULL.
91  */
92 struct hostkey_foreach_line {
93           const char *path; /* Path of file */
94           u_long linenum;     /* Line number */
95           u_int status;       /* One of HKF_STATUS_* */
96           u_int match;        /* Zero or more of HKF_MATCH_* OR'd together */
97           char *line;         /* Entire key line; mutable by callback */
98           int marker;         /* CA/revocation markers; indicated by MRK_* value */
99           const char *hosts; /* Raw hosts text, may be hashed or list multiple */
100           const char *rawkey; /* Text of key and any comment following it */
101           int keytype;        /* Type of key; KEY_UNSPEC for invalid/comment lines */
102           struct sshkey *key; /* Key, if parsed ok and HKF_WANT_MATCH_HOST set */
103           const char *comment; /* Any comment following the key */
104           u_int note;         /* caller-specified note copied from arguments */
105 };
106 
107 /*
108  * Callback fires for each line (or matching line if a HKF_WANT_* option
109  * is set). The foreach loop will terminate if the callback returns a non-
110  * zero exit status.
111  */
112 typedef int hostkeys_foreach_fn(struct hostkey_foreach_line *l, void *ctx);
113 
114 /* Iterate over a hostkeys file */
115 int hostkeys_foreach(const char *path,
116     hostkeys_foreach_fn *callback, void *ctx,
117     const char *host, const char *ip, u_int options, u_int note);
118 int hostkeys_foreach_file(const char *path, FILE *f,
119     hostkeys_foreach_fn *callback, void *ctx,
120     const char *host, const char *ip, u_int options, u_int note);
121 
122 void hostfile_create_user_ssh_dir(const char *, int);
123 
124 #endif
125