openssh/hostfile.h
djm@openbsd.org 8d4f87258f upstream commit
Host key rotation support.

Add a hostkeys@openssh.com protocol extension (global request) for
a server to inform a client of all its available host key after
authentication has completed. The client may record the keys in
known_hosts, allowing it to upgrade to better host key algorithms
and a server to gracefully rotate its keys.

The client side of this is controlled by a UpdateHostkeys config
option (default on).

ok markus@
2015-01-27 00:00:57 +11:00

100 lines
3.4 KiB
C

/* $OpenBSD: hostfile.h,v 1.23 2015/01/26 03:04:45 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
#ifndef HOSTFILE_H
#define HOSTFILE_H
typedef enum {
HOST_OK, HOST_NEW, HOST_CHANGED, HOST_REVOKED, HOST_FOUND
} HostStatus;
typedef enum {
MRK_ERROR, MRK_NONE, MRK_REVOKE, MRK_CA
} HostkeyMarker;
struct hostkey_entry {
char *host;
char *file;
u_long line;
struct sshkey *key;
HostkeyMarker marker;
};
struct hostkeys;
struct hostkeys *init_hostkeys(void);
void load_hostkeys(struct hostkeys *, const char *, const char *);
void free_hostkeys(struct hostkeys *);
HostStatus check_key_in_hostkeys(struct hostkeys *, struct sshkey *,
const struct hostkey_entry **);
int lookup_key_in_hostkeys_by_type(struct hostkeys *, int,
const struct hostkey_entry **);
int hostfile_read_key(char **, u_int *, struct sshkey *);
int add_host_to_hostfile(const char *, const char *,
const struct sshkey *, int);
int hostfile_replace_entries(const char *filename, const char *host,
struct sshkey **keys, size_t nkeys, int store_hash, int quiet);
#define HASH_MAGIC "|1|"
#define HASH_DELIM '|'
#define CA_MARKER "@cert-authority"
#define REVOKE_MARKER "@revoked"
char *host_hash(const char *, const char *, u_int);
/*
* Iterate through a hostkeys file, optionally parsing keys and matching
* hostnames. Allows access to the raw keyfile lines to allow
* streaming edits to the file to take place.
*/
#define HKF_WANT_MATCH_HOST (1) /* return only matching hosts */
#define HKF_WANT_PARSE_KEY (1<<1) /* need key parsed */
#define HKF_STATUS_OK 1 /* Line parsed, didn't match host */
#define HKF_STATUS_INVALID 2 /* line had parse error */
#define HKF_STATUS_COMMENT 3 /* valid line contained no key */
#define HKF_STATUS_HOST_MATCHED 4 /* hostname matched */
/*
* The callback function receives this as an argument for each matching
* hostkey line. The callback may "steal" the 'key' field by setting it to NULL.
* If a parse error occurred, then "hosts" and subsequent options may be NULL.
*/
struct hostkey_foreach_line {
const char *path; /* Path of file */
u_long linenum; /* Line number */
int status; /* One of HKF_STATUS_* */
char *line; /* Entire key line; mutable by callback */
int marker; /* CA/revocation markers; indicated by MRK_* value */
const char *hosts; /* Raw hosts text, may be hashed or list multiple */
int was_hashed; /* Non-zero if hostname was hashed */
const char *rawkey; /* Text of key and any comment following it */
struct sshkey *key; /* Key, if parsed ok and HKF_WANT_MATCH_HOST set */
const char *comment; /* Any comment following the key */
};
/*
* Callback fires for each line (or matching line if a HKF_WANT_* option
* is set). The foreach loop will terminate if the callback returns a non-
* zero exit status.
*/
typedef int hostkeys_foreach_fn(struct hostkey_foreach_line *l, void *ctx);
int hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
const char *host, u_int options);
#endif