hostfile.h

   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