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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2016 Joyent, Inc.
*/
#include <alloca.h>
#include <door.h>
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <openssl/rsa.h>
#include <md5.h>
#ifdef __cplusplus
extern "C" {
#endif
#define LOG_OOM(SZ) (void) fprintf(stderr, "Cannot alloca %d bytes\n", SZ)
static const char *DOOR = "/var/tmp/._joyent_sshd_key_is_authorized";
static const char *REQ_FMT_STR = "%s %d %s"; /* name uid fp */
static const int RETURN_SZ = 2;
static const int MAX_ATTEMPTS = 2;
static const int SLEEP_PERIOD = 1;
static int
sshd_allowed_in_capi(struct passwd *pw, const char *fp)
{
int allowed = 0;
int fd = -1;
int blen = 0;
int attempts = 0;
char *buf = NULL;
door_arg_t door_args = {0};
if (pw == NULL || fp == NULL)
return (0);
blen = snprintf(NULL, 0, REQ_FMT_STR, pw->pw_name, pw->pw_uid, fp) + 1;
buf = (char *)alloca(blen);
if (buf == NULL) {
LOG_OOM(blen);
return (0);
}
(void) snprintf(buf, blen, REQ_FMT_STR, pw->pw_name, pw->pw_uid, fp);
door_args.data_ptr = buf;
door_args.data_size = blen;
door_args.rsize = RETURN_SZ;
door_args.rbuf = alloca(RETURN_SZ);
if (door_args.rbuf == NULL) {
LOG_OOM(RETURN_SZ);
return (0);
}
(void) memset(door_args.rbuf, 0, RETURN_SZ);
do {
fd = open(DOOR, O_RDWR);
if (fd < 0) {
if (errno == ENOENT) {
/*
* On systems which are not running SmartLogin,
* such as vanilla SmartOS, the door will be
* completely absent. The sleep/retry loop is
* skipped in this case to keep the login
* process more lively.
*/
perror("smartplugin: door does not exist");
return (0);
}
perror("smartplugin: open (of door FD) failed");
} else if (door_call(fd, &door_args) < 0) {
perror("smartplugin: door_call failed");
} else {
allowed = atoi(door_args.rbuf);
if (door_args.rsize > RETURN_SZ) {
/*
* Given what we know about the SmartLogin
* daemon on the other end of the door, this
* should never occur. An assert might be
* preferable, but that is avoided since the
* error can be handled.
*/
(void) munmap(door_args.rbuf, door_args.rsize);
}
return (allowed);
}
if (++attempts < MAX_ATTEMPTS) {
(void) sleep(SLEEP_PERIOD);
}
} while (attempts < MAX_ATTEMPTS);
return (0);
}
static int
tohexstr(uchar_t *bytes, size_t blen, char *hexstr, size_t hexlen)
{
size_t i, j;
const char hexlist[] = "0123456789abcdef";
if (hexlen < 1)
return (-1);
for (i = 0, j = 0; i < blen; i++) {
/*
* We need 3 bytes output per input byte -- the third byte is
* either for a : or the \0 at the end.
*/
if (hexlen < (j + 3))
return (-1);
hexstr[j++] = hexlist[(bytes[i] >> 4) & 0xf];
hexstr[j++] = hexlist[bytes[i] & 0xf];
if (i + 1 < blen)
hexstr[j++] = ':';
}
hexstr[j] = '\0';
return (0);
}
/* ARGSUSED */
int
sshd_user_key_allowed(struct passwd *pw, const char *type,
const unsigned char *buf, size_t size)
{
unsigned char md5buf[MD5_DIGEST_LENGTH];
/*
* Will contain the fingerprint MD5 in colonhex format. Need 3 bytes
* per MD5 byte: two for hex digits, plus one for either ':' or '\0'.
*/
char hex[MD5_DIGEST_LENGTH * 3];
md5_calc(md5buf, buf, size);
if (tohexstr(md5buf, sizeof (md5buf), hex, sizeof (hex)) != 0)
return (0);
return (sshd_allowed_in_capi(pw, hex));
}
/* ARGSUSED */
int
sshd_user_rsa_key_allowed(struct passwd *pw, RSA *key, const char *fp)
{
return (sshd_allowed_in_capi(pw, fp));
}
/* ARGSUSED */
int
sshd_user_dsa_key_allowed(struct passwd *pw, DSA *key, const char *fp)
{
return (sshd_allowed_in_capi(pw, fp));
}
/* ARGSUSED */
int
sshd_user_ecdsa_key_allowed(struct passwd *pw, DSA *key, const char *fp)
{
return (sshd_allowed_in_capi(pw, fp));
}
#ifdef __cplusplus
}
#endif
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