FreeBSD-5.3/lib/libtacplus/taclib.c
/*-
* Copyright (c) 1998, 2001, 2002, Juniper Networks, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libtacplus/taclib.c,v 1.5 2002/09/25 23:18:51 pst Exp $");
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <md5.h>
#include <netdb.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "taclib_private.h"
static int add_str_8(struct tac_handle *, u_int8_t *,
struct clnt_str *);
static int add_str_16(struct tac_handle *, u_int16_t *,
struct clnt_str *);
static int protocol_version(int, int, int);
static void close_connection(struct tac_handle *);
static int conn_server(struct tac_handle *);
static void crypt_msg(struct tac_handle *, struct tac_msg *);
static void *dup_str(struct tac_handle *, const struct srvr_str *,
size_t *);
static int establish_connection(struct tac_handle *);
static void free_str(struct clnt_str *);
static void generr(struct tac_handle *, const char *, ...)
__printflike(2, 3);
static void gen_session_id(struct tac_msg *);
static int get_srvr_end(struct tac_handle *);
static int get_srvr_str(struct tac_handle *, const char *,
struct srvr_str *, size_t);
static void init_clnt_str(struct clnt_str *);
static void init_srvr_str(struct srvr_str *);
static int read_timed(struct tac_handle *, void *, size_t,
const struct timeval *);
static int recv_msg(struct tac_handle *);
static int save_str(struct tac_handle *, struct clnt_str *,
const void *, size_t);
static int send_msg(struct tac_handle *);
static int split(char *, char *[], int, char *, size_t);
static void *xmalloc(struct tac_handle *, size_t);
static char *xstrdup(struct tac_handle *, const char *);
static void clear_srvr_avs(struct tac_handle *);
static void create_msg(struct tac_handle *, int, int, int);
/*
* Append some optional data to the current request, and store its
* length into the 8-bit field referenced by "fld". Returns 0 on
* success, or -1 on failure.
*
* This function also frees the "cs" string data and initializes it
* for the next time.
*/
static int
add_str_8(struct tac_handle *h, u_int8_t *fld, struct clnt_str *cs)
{
u_int16_t len;
if (add_str_16(h, &len, cs) == -1)
return -1;
len = ntohs(len);
if (len > 0xff) {
generr(h, "Field too long");
return -1;
}
*fld = len;
return 0;
}
/*
* Append some optional data to the current request, and store its
* length into the 16-bit field (network byte order) referenced by
* "fld". Returns 0 on success, or -1 on failure.
*
* This function also frees the "cs" string data and initializes it
* for the next time.
*/
static int
add_str_16(struct tac_handle *h, u_int16_t *fld, struct clnt_str *cs)
{
size_t len;
len = cs->len;
if (cs->data == NULL)
len = 0;
if (len != 0) {
int offset;
if (len > 0xffff) {
generr(h, "Field too long");
return -1;
}
offset = ntohl(h->request.length);
if (offset + len > BODYSIZE) {
generr(h, "Message too long");
return -1;
}
memcpy(h->request.u.body + offset, cs->data, len);
h->request.length = htonl(offset + len);
}
*fld = htons(len);
free_str(cs);
return 0;
}
static int
protocol_version(int msg_type, int var, int type)
{
int minor;
switch (msg_type) {
case TAC_AUTHEN:
/* 'var' represents the 'action' */
switch (var) {
case TAC_AUTHEN_LOGIN:
switch (type) {
case TAC_AUTHEN_TYPE_PAP:
case TAC_AUTHEN_TYPE_CHAP:
case TAC_AUTHEN_TYPE_MSCHAP:
case TAC_AUTHEN_TYPE_ARAP:
minor = 1;
break;
default:
minor = 0;
break;
}
break;
case TAC_AUTHEN_SENDAUTH:
minor = 1;
break;
default:
minor = 0;
break;
};
break;
case TAC_AUTHOR:
/* 'var' represents the 'method' */
switch (var) {
/*
* When new authentication methods are added, include 'method'
* in determining the value of 'minor'. At this point, all
* methods defined in this implementation (see "Authorization
* authentication methods" in taclib.h) are minor version 0
* Not all types, however, indicate minor version 0.
*/
case TAC_AUTHEN_METH_NOT_SET:
case TAC_AUTHEN_METH_NONE:
case TAC_AUTHEN_METH_KRB5:
case TAC_AUTHEN_METH_LINE:
case TAC_AUTHEN_METH_ENABLE:
case TAC_AUTHEN_METH_LOCAL:
case TAC_AUTHEN_METH_TACACSPLUS:
case TAC_AUTHEN_METH_RCMD:
switch (type) {
case TAC_AUTHEN_TYPE_PAP:
case TAC_AUTHEN_TYPE_CHAP:
case TAC_AUTHEN_TYPE_MSCHAP:
case TAC_AUTHEN_TYPE_ARAP:
minor = 1;
break;
default:
minor = 0;
break;
}
break;
default:
minor = 0;
break;
}
break;
default:
minor = 0;
break;
}
return TAC_VER_MAJOR << 4 | minor;
}
static void
close_connection(struct tac_handle *h)
{
if (h->fd != -1) {
close(h->fd);
h->fd = -1;
}
}
static int
conn_server(struct tac_handle *h)
{
const struct tac_server *srvp = &h->servers[h->cur_server];
int flags;
if ((h->fd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {
generr(h, "Cannot create socket: %s", strerror(errno));
return -1;
}
if ((flags = fcntl(h->fd, F_GETFL, 0)) == -1 ||
fcntl(h->fd, F_SETFL, flags | O_NONBLOCK) == -1) {
generr(h, "Cannot set non-blocking mode on socket: %s",
strerror(errno));
close(h->fd);
h->fd = -1;
return -1;
}
if (connect(h->fd, (struct sockaddr *)&srvp->addr,
sizeof srvp->addr) == 0)
return 0;
if (errno == EINPROGRESS) {
fd_set wfds;
struct timeval tv;
int nfds;
struct sockaddr peer;
int peerlen;
int err;
int errlen;
/* Wait for the connection to complete. */
FD_ZERO(&wfds);
FD_SET(h->fd, &wfds);
tv.tv_sec = srvp->timeout;
tv.tv_usec = 0;
nfds = select(h->fd + 1, NULL, &wfds, NULL, &tv);
if (nfds == -1) {
generr(h, "select: %s", strerror(errno));
close(h->fd);
h->fd = -1;
return -1;
}
if (nfds == 0) {
generr(h, "connect: timed out");
close(h->fd);
h->fd = -1;
return -1;
}
/* See whether we are connected now. */
peerlen = sizeof peer;
if (getpeername(h->fd, &peer, &peerlen) == 0)
return 0;
if (errno != ENOTCONN) {
generr(h, "getpeername: %s", strerror(errno));
close(h->fd);
h->fd = -1;
return -1;
}
/* Find out why the connect failed. */
errlen = sizeof err;
getsockopt(h->fd, SOL_SOCKET, SO_ERROR, &err, &errlen);
errno = err;
}
generr(h, "connect: %s", strerror(errno));
close(h->fd);
h->fd = -1;
return -1;
}
/*
* Encrypt or decrypt a message. The operations are symmetrical.
*/
static void
crypt_msg(struct tac_handle *h, struct tac_msg *msg)
{
const char *secret;
MD5_CTX base_ctx;
MD5_CTX ctx;
unsigned char md5[16];
int chunk;
int msg_len;
secret = h->servers[h->cur_server].secret;
if (secret[0] == '\0')
msg->flags |= TAC_UNENCRYPTED;
if (msg->flags & TAC_UNENCRYPTED)
return;
msg_len = ntohl(msg->length);
MD5Init(&base_ctx);
MD5Update(&base_ctx, msg->session_id, sizeof msg->session_id);
MD5Update(&base_ctx, secret, strlen(secret));
MD5Update(&base_ctx, &msg->version, sizeof msg->version);
MD5Update(&base_ctx, &msg->seq_no, sizeof msg->seq_no);
ctx = base_ctx;
for (chunk = 0; chunk < msg_len; chunk += sizeof md5) {
int chunk_len;
int i;
MD5Final(md5, &ctx);
if ((chunk_len = msg_len - chunk) > sizeof md5)
chunk_len = sizeof md5;
for (i = 0; i < chunk_len; i++)
msg->u.body[chunk + i] ^= md5[i];
ctx = base_ctx;
MD5Update(&ctx, md5, sizeof md5);
}
}
/*
* Return a dynamically allocated copy of the given server string.
* The copy is null-terminated. If "len" is non-NULL, the length of
* the string (excluding the terminating null byte) is stored via it.
* Returns NULL on failure. Empty strings are still allocated even
* though they have no content.
*/
static void *
dup_str(struct tac_handle *h, const struct srvr_str *ss, size_t *len)
{
unsigned char *p;
if ((p = (unsigned char *)xmalloc(h, ss->len + 1)) == NULL)
return NULL;
if (ss->data != NULL && ss->len != 0)
memcpy(p, ss->data, ss->len);
p[ss->len] = '\0';
if (len != NULL)
*len = ss->len;
return p;
}
static int
establish_connection(struct tac_handle *h)
{
int i;
if (h->fd >= 0) /* Already connected. */
return 0;
if (h->num_servers == 0) {
generr(h, "No TACACS+ servers specified");
return -1;
}
/*
* Try the servers round-robin. We begin with the one that
* worked for us the last time. That way, once we find a good
* server, we won't waste any more time trying the bad ones.
*/
for (i = 0; i < h->num_servers; i++) {
if (conn_server(h) == 0) {
h->single_connect = (h->servers[h->cur_server].flags &
TAC_SRVR_SINGLE_CONNECT) != 0;
return 0;
}
if (++h->cur_server >= h->num_servers) /* Wrap around */
h->cur_server = 0;
}
/* Just return whatever error was last reported by conn_server(). */
return -1;
}
/*
* Free a client string, obliterating its contents first for security.
*/
static void
free_str(struct clnt_str *cs)
{
if (cs->data != NULL) {
memset(cs->data, 0, cs->len);
free(cs->data);
cs->data = NULL;
cs->len = 0;
}
}
static void
generr(struct tac_handle *h, const char *format, ...)
{
va_list ap;
va_start(ap, format);
vsnprintf(h->errmsg, ERRSIZE, format, ap);
va_end(ap);
}
static void
gen_session_id(struct tac_msg *msg)
{
int r;
r = random();
msg->session_id[0] = r >> 8;
msg->session_id[1] = r;
r = random();
msg->session_id[2] = r >> 8;
msg->session_id[3] = r;
}
/*
* Verify that we are exactly at the end of the response message.
* Returns 0 on success, -1 on failure.
*/
static int
get_srvr_end(struct tac_handle *h)
{
int len;
len = ntohl(h->response.length);
if (h->srvr_pos != len) {
generr(h, "Invalid length field in response "
"from server: end expected at %u, response length %u",
h->srvr_pos, len);
return -1;
}
return 0;
}
static int
get_srvr_str(struct tac_handle *h, const char *field,
struct srvr_str *ss, size_t len)
{
if (h->srvr_pos + len > ntohl(h->response.length)) {
generr(h, "Invalid length field in %s response from server "
"(%lu > %lu)", field, (u_long)(h->srvr_pos + len),
(u_long)ntohl(h->response.length));
return -1;
}
ss->data = len != 0 ? h->response.u.body + h->srvr_pos : NULL;
ss->len = len;
h->srvr_pos += len;
return 0;
}
static void
init_clnt_str(struct clnt_str *cs)
{
cs->data = NULL;
cs->len = 0;
}
static void
init_srvr_str(struct srvr_str *ss)
{
ss->data = NULL;
ss->len = 0;
}
static int
read_timed(struct tac_handle *h, void *buf, size_t len,
const struct timeval *deadline)
{
char *ptr;
ptr = (char *)buf;
while (len > 0) {
int n;
n = read(h->fd, ptr, len);
if (n == -1) {
struct timeval tv;
int nfds;
if (errno != EAGAIN) {
generr(h, "Network read error: %s",
strerror(errno));
return -1;
}
/* Wait until we can read more data. */
gettimeofday(&tv, NULL);
timersub(deadline, &tv, &tv);
if (tv.tv_sec >= 0) {
fd_set rfds;
FD_ZERO(&rfds);
FD_SET(h->fd, &rfds);
nfds =
select(h->fd + 1, &rfds, NULL, NULL, &tv);
if (nfds == -1) {
generr(h, "select: %s",
strerror(errno));
return -1;
}
} else
nfds = 0;
if (nfds == 0) {
generr(h, "Network read timed out");
return -1;
}
} else if (n == 0) {
generr(h, "unexpected EOF from server");
return -1;
} else {
ptr += n;
len -= n;
}
}
return 0;
}
/*
* Receive a response from the server and decrypt it. Returns 0 on
* success, or -1 on failure.
*/
static int
recv_msg(struct tac_handle *h)
{
struct timeval deadline;
struct tac_msg *msg;
u_int32_t len;
msg = &h->response;
gettimeofday(&deadline, NULL);
deadline.tv_sec += h->servers[h->cur_server].timeout;
/* Read the message header and make sure it is reasonable. */
if (read_timed(h, msg, HDRSIZE, &deadline) == -1)
return -1;
if (memcmp(msg->session_id, h->request.session_id,
sizeof msg->session_id) != 0) {
generr(h, "Invalid session ID in received message");
return -1;
}
if (msg->type != h->request.type) {
generr(h, "Invalid type in received message"
" (got %u, expected %u)",
msg->type, h->request.type);
return -1;
}
len = ntohl(msg->length);
if (len > BODYSIZE) {
generr(h, "Received message too large (%u > %u)",
len, BODYSIZE);
return -1;
}
if (msg->seq_no != ++h->last_seq_no) {
generr(h, "Invalid sequence number in received message"
" (got %u, expected %u)",
msg->seq_no, h->last_seq_no);
return -1;
}
/* Read the message body. */
if (read_timed(h, msg->u.body, len, &deadline) == -1)
return -1;
/* Decrypt it. */
crypt_msg(h, msg);
/*
* Turn off single-connection mode if the server isn't amenable
* to it.
*/
if (!(msg->flags & TAC_SINGLE_CONNECT))
h->single_connect = 0;
return 0;
}
static int
save_str(struct tac_handle *h, struct clnt_str *cs, const void *data,
size_t len)
{
free_str(cs);
if (data != NULL && len != 0) {
if ((cs->data = xmalloc(h, len)) == NULL)
return -1;
cs->len = len;
memcpy(cs->data, data, len);
}
return 0;
}
/*
* Send the current request, after encrypting it. Returns 0 on success,
* or -1 on failure.
*/
static int
send_msg(struct tac_handle *h)
{
struct timeval deadline;
struct tac_msg *msg;
char *ptr;
int len;
if (h->last_seq_no & 1) {
generr(h, "Attempt to send message out of sequence");
return -1;
}
if (establish_connection(h) == -1)
return -1;
msg = &h->request;
msg->seq_no = ++h->last_seq_no;
if (msg->seq_no == 1)
gen_session_id(msg);
crypt_msg(h, msg);
if (h->single_connect)
msg->flags |= TAC_SINGLE_CONNECT;
else
msg->flags &= ~TAC_SINGLE_CONNECT;
gettimeofday(&deadline, NULL);
deadline.tv_sec += h->servers[h->cur_server].timeout;
len = HDRSIZE + ntohl(msg->length);
ptr = (char *)msg;
while (len > 0) {
int n;
n = write(h->fd, ptr, len);
if (n == -1) {
struct timeval tv;
int nfds;
if (errno != EAGAIN) {
generr(h, "Network write error: %s",
strerror(errno));
return -1;
}
/* Wait until we can write more data. */
gettimeofday(&tv, NULL);
timersub(&deadline, &tv, &tv);
if (tv.tv_sec >= 0) {
fd_set wfds;
FD_ZERO(&wfds);
FD_SET(h->fd, &wfds);
nfds =
select(h->fd + 1, NULL, &wfds, NULL, &tv);
if (nfds == -1) {
generr(h, "select: %s",
strerror(errno));
return -1;
}
} else
nfds = 0;
if (nfds == 0) {
generr(h, "Network write timed out");
return -1;
}
} else {
ptr += n;
len -= n;
}
}
return 0;
}
/*
* Destructively split a string into fields separated by white space.
* `#' at the beginning of a field begins a comment that extends to the
* end of the string. Fields may be quoted with `"'. Inside quoted
* strings, the backslash escapes `\"' and `\\' are honored.
*
* Pointers to up to the first maxfields fields are stored in the fields
* array. Missing fields get NULL pointers.
*
* The return value is the actual number of fields parsed, and is always
* <= maxfields.
*
* On a syntax error, places a message in the msg string, and returns -1.
*/
static int
split(char *str, char *fields[], int maxfields, char *msg, size_t msglen)
{
char *p;
int i;
static const char ws[] = " \t";
for (i = 0; i < maxfields; i++)
fields[i] = NULL;
p = str;
i = 0;
while (*p != '\0') {
p += strspn(p, ws);
if (*p == '#' || *p == '\0')
break;
if (i >= maxfields) {
snprintf(msg, msglen, "line has too many fields");
return -1;
}
if (*p == '"') {
char *dst;
dst = ++p;
fields[i] = dst;
while (*p != '"') {
if (*p == '\\') {
p++;
if (*p != '"' && *p != '\\' &&
*p != '\0') {
snprintf(msg, msglen,
"invalid `\\' escape");
return -1;
}
}
if (*p == '\0') {
snprintf(msg, msglen,
"unterminated quoted string");
return -1;
}
*dst++ = *p++;
}
*dst = '\0';
p++;
if (*p != '\0' && strspn(p, ws) == 0) {
snprintf(msg, msglen, "quoted string not"
" followed by white space");
return -1;
}
} else {
fields[i] = p;
p += strcspn(p, ws);
if (*p != '\0')
*p++ = '\0';
}
i++;
}
return i;
}
int
tac_add_server(struct tac_handle *h, const char *host, int port,
const char *secret, int timeout, int flags)
{
struct tac_server *srvp;
if (h->num_servers >= MAXSERVERS) {
generr(h, "Too many TACACS+ servers specified");
return -1;
}
srvp = &h->servers[h->num_servers];
memset(&srvp->addr, 0, sizeof srvp->addr);
srvp->addr.sin_len = sizeof srvp->addr;
srvp->addr.sin_family = AF_INET;
if (!inet_aton(host, &srvp->addr.sin_addr)) {
struct hostent *hent;
if ((hent = gethostbyname(host)) == NULL) {
generr(h, "%s: host not found", host);
return -1;
}
memcpy(&srvp->addr.sin_addr, hent->h_addr,
sizeof srvp->addr.sin_addr);
}
srvp->addr.sin_port = htons(port != 0 ? port : TACPLUS_PORT);
if ((srvp->secret = xstrdup(h, secret)) == NULL)
return -1;
srvp->timeout = timeout;
srvp->flags = flags;
h->num_servers++;
return 0;
}
void
tac_close(struct tac_handle *h)
{
int i, srv;
if (h->fd != -1)
close(h->fd);
for (srv = 0; srv < h->num_servers; srv++) {
memset(h->servers[srv].secret, 0,
strlen(h->servers[srv].secret));
free(h->servers[srv].secret);
}
free_str(&h->user);
free_str(&h->port);
free_str(&h->rem_addr);
free_str(&h->data);
free_str(&h->user_msg);
for (i=0; i<MAXAVPAIRS; i++)
free_str(&(h->avs[i]));
/* Clear everything else before freeing memory */
memset(h, 0, sizeof(struct tac_handle));
free(h);
}
int
tac_config(struct tac_handle *h, const char *path)
{
FILE *fp;
char buf[MAXCONFLINE];
int linenum;
int retval;
if (path == NULL)
path = PATH_TACPLUS_CONF;
if ((fp = fopen(path, "r")) == NULL) {
generr(h, "Cannot open \"%s\": %s", path, strerror(errno));
return -1;
}
retval = 0;
linenum = 0;
while (fgets(buf, sizeof buf, fp) != NULL) {
int len;
char *fields[4];
int nfields;
char msg[ERRSIZE];
char *host, *res;
char *port_str;
char *secret;
char *timeout_str;
char *options_str;
char *end;
unsigned long timeout;
int port;
int options;
linenum++;
len = strlen(buf);
/* We know len > 0, else fgets would have returned NULL. */
if (buf[len - 1] != '\n') {
if (len >= sizeof buf - 1)
generr(h, "%s:%d: line too long", path,
linenum);
else
generr(h, "%s:%d: missing newline", path,
linenum);
retval = -1;
break;
}
buf[len - 1] = '\0';
/* Extract the fields from the line. */
nfields = split(buf, fields, 4, msg, sizeof msg);
if (nfields == -1) {
generr(h, "%s:%d: %s", path, linenum, msg);
retval = -1;
break;
}
if (nfields == 0)
continue;
if (nfields < 2) {
generr(h, "%s:%d: missing shared secret", path,
linenum);
retval = -1;
break;
}
host = fields[0];
secret = fields[1];
timeout_str = fields[2];
options_str = fields[3];
/* Parse and validate the fields. */
res = host;
host = strsep(&res, ":");
port_str = strsep(&res, ":");
if (port_str != NULL) {
port = strtoul(port_str, &end, 10);
if (port_str[0] == '\0' || *end != '\0') {
generr(h, "%s:%d: invalid port", path,
linenum);
retval = -1;
break;
}
} else
port = 0;
if (timeout_str != NULL) {
timeout = strtoul(timeout_str, &end, 10);
if (timeout_str[0] == '\0' || *end != '\0') {
generr(h, "%s:%d: invalid timeout", path,
linenum);
retval = -1;
break;
}
} else
timeout = TIMEOUT;
options = 0;
if (options_str != NULL) {
if (strcmp(options_str, "single-connection") == 0)
options |= TAC_SRVR_SINGLE_CONNECT;
else {
generr(h, "%s:%d: invalid option \"%s\"",
path, linenum, options_str);
retval = -1;
break;
}
};
if (tac_add_server(h, host, port, secret, timeout,
options) == -1) {
char msg[ERRSIZE];
strcpy(msg, h->errmsg);
generr(h, "%s:%d: %s", path, linenum, msg);
retval = -1;
break;
}
}
/* Clear out the buffer to wipe a possible copy of a shared secret */
memset(buf, 0, sizeof buf);
fclose(fp);
return retval;
}
int
tac_create_authen(struct tac_handle *h, int action, int type, int service)
{
struct tac_authen_start *as;
create_msg(h, TAC_AUTHEN, action, type);
as = &h->request.u.authen_start;
as->action = action;
as->priv_lvl = TAC_PRIV_LVL_USER;
as->authen_type = type;
as->service = service;
return 0;
}
int
tac_create_author(struct tac_handle *h, int method, int type, int service)
{
struct tac_author_request *areq;
create_msg(h, TAC_AUTHOR, method, type);
areq = &h->request.u.author_request;
areq->authen_meth = method;
areq->priv_lvl = TAC_PRIV_LVL_USER;
areq->authen_type = type;
areq->service = service;
return 0;
}
static void
create_msg(struct tac_handle *h, int msg_type, int var, int type)
{
struct tac_msg *msg;
int i;
h->last_seq_no = 0;
msg = &h->request;
msg->type = msg_type;
msg->version = protocol_version(msg_type, var, type);
msg->flags = 0; /* encrypted packet body */
free_str(&h->user);
free_str(&h->port);
free_str(&h->rem_addr);
free_str(&h->data);
free_str(&h->user_msg);
for (i=0; i<MAXAVPAIRS; i++)
free_str(&(h->avs[i]));
}
void *
tac_get_data(struct tac_handle *h, size_t *len)
{
return dup_str(h, &h->srvr_data, len);
}
char *
tac_get_msg(struct tac_handle *h)
{
return dup_str(h, &h->srvr_msg, NULL);
}
/*
* Create and initialize a tac_handle structure, and return it to the
* caller. Can fail only if the necessary memory cannot be allocated.
* In that case, it returns NULL.
*/
struct tac_handle *
tac_open(void)
{
int i;
struct tac_handle *h;
h = (struct tac_handle *)malloc(sizeof(struct tac_handle));
if (h != NULL) {
h->fd = -1;
h->num_servers = 0;
h->cur_server = 0;
h->errmsg[0] = '\0';
init_clnt_str(&h->user);
init_clnt_str(&h->port);
init_clnt_str(&h->rem_addr);
init_clnt_str(&h->data);
init_clnt_str(&h->user_msg);
for (i=0; i<MAXAVPAIRS; i++) {
init_clnt_str(&(h->avs[i]));
init_srvr_str(&(h->srvr_avs[i]));
}
init_srvr_str(&h->srvr_msg);
init_srvr_str(&h->srvr_data);
srandomdev();
}
return h;
}
int
tac_send_authen(struct tac_handle *h)
{
struct tac_authen_reply *ar;
if (h->num_servers == 0)
return -1;
if (h->last_seq_no == 0) { /* Authentication START packet */
struct tac_authen_start *as;
as = &h->request.u.authen_start;
h->request.length =
htonl(offsetof(struct tac_authen_start, rest[0]));
if (add_str_8(h, &as->user_len, &h->user) == -1 ||
add_str_8(h, &as->port_len, &h->port) == -1 ||
add_str_8(h, &as->rem_addr_len, &h->rem_addr) == -1 ||
add_str_8(h, &as->data_len, &h->data) == -1)
return -1;
} else { /* Authentication CONTINUE packet */
struct tac_authen_cont *ac;
ac = &h->request.u.authen_cont;
ac->flags = 0;
h->request.length =
htonl(offsetof(struct tac_authen_cont, rest[0]));
if (add_str_16(h, &ac->user_msg_len, &h->user_msg) == -1 ||
add_str_16(h, &ac->data_len, &h->data) == -1)
return -1;
}
/* Send the message and retrieve the reply. */
if (send_msg(h) == -1 || recv_msg(h) == -1)
return -1;
/* Scan the optional fields in the reply. */
ar = &h->response.u.authen_reply;
h->srvr_pos = offsetof(struct tac_authen_reply, rest[0]);
if (get_srvr_str(h, "msg", &h->srvr_msg, ntohs(ar->msg_len)) == -1 ||
get_srvr_str(h, "data", &h->srvr_data, ntohs(ar->data_len)) == -1 ||
get_srvr_end(h) == -1)
return -1;
if (!h->single_connect &&
ar->status != TAC_AUTHEN_STATUS_GETDATA &&
ar->status != TAC_AUTHEN_STATUS_GETUSER &&
ar->status != TAC_AUTHEN_STATUS_GETPASS)
close_connection(h);
return ar->flags << 8 | ar->status;
}
int
tac_send_author(struct tac_handle *h)
{
int i, current;
char dbgstr[64];
struct tac_author_request *areq = &h->request.u.author_request;
struct tac_author_response *ares = &h->response.u.author_response;
h->request.length =
htonl(offsetof(struct tac_author_request, rest[0]));
/* Count each specified AV pair */
for (areq->av_cnt=0, i=0; i<MAXAVPAIRS; i++)
if (h->avs[i].len && h->avs[i].data)
areq->av_cnt++;
/*
* Each AV size is a byte starting right after 'av_cnt'. Update the
* offset to include these AV sizes.
*/
h->request.length = ntohl(htonl(h->request.length) + areq->av_cnt);
/* Now add the string arguments from 'h' */
if (add_str_8(h, &areq->user_len, &h->user) == -1 ||
add_str_8(h, &areq->port_len, &h->port) == -1 ||
add_str_8(h, &areq->rem_addr_len, &h->rem_addr) == -1)
return -1;
/* Add each AV pair, the size of each placed in areq->rest[current] */
for (current=0, i=0; i<MAXAVPAIRS; i++) {
if (h->avs[i].len && h->avs[i].data) {
if (add_str_8(h, &areq->rest[current++],
&(h->avs[i])) == -1)
return -1;
}
}
/* Send the message and retrieve the reply. */
if (send_msg(h) == -1 || recv_msg(h) == -1)
return -1;
/* Update the offset in the response packet based on av pairs count */
h->srvr_pos = offsetof(struct tac_author_response, rest[0]) +
ares->av_cnt;
/* Scan the optional fields in the response. */
if (get_srvr_str(h, "msg", &h->srvr_msg, ntohs(ares->msg_len)) == -1 ||
get_srvr_str(h, "data", &h->srvr_data, ntohs(ares->data_len)) ==-1)
return -1;
/* Get each AV pair (just setting pointers, not malloc'ing) */
clear_srvr_avs(h);
for (i=0; i<ares->av_cnt; i++) {
snprintf(dbgstr, sizeof dbgstr, "av-pair-%d", i);
if (get_srvr_str(h, dbgstr, &(h->srvr_avs[i]),
ares->rest[i]) == -1)
return -1;
}
/* Should have ended up at the end */
if (get_srvr_end(h) == -1)
return -1;
/* Sanity checks */
if (!h->single_connect)
close_connection(h);
return ares->av_cnt << 8 | ares->status;
}
int
tac_set_rem_addr(struct tac_handle *h, const char *addr)
{
return save_str(h, &h->rem_addr, addr, addr != NULL ? strlen(addr) : 0);
}
int
tac_set_data(struct tac_handle *h, const void *data, size_t data_len)
{
return save_str(h, &h->data, data, data_len);
}
int
tac_set_msg(struct tac_handle *h, const char *msg)
{
return save_str(h, &h->user_msg, msg, msg != NULL ? strlen(msg) : 0);
}
int
tac_set_port(struct tac_handle *h, const char *port)
{
return save_str(h, &h->port, port, port != NULL ? strlen(port) : 0);
}
int
tac_set_priv(struct tac_handle *h, int priv)
{
if (!(TAC_PRIV_LVL_MIN <= priv && priv <= TAC_PRIV_LVL_MAX)) {
generr(h, "Attempt to set invalid privilege level");
return -1;
}
h->request.u.authen_start.priv_lvl = priv;
return 0;
}
int
tac_set_user(struct tac_handle *h, const char *user)
{
return save_str(h, &h->user, user, user != NULL ? strlen(user) : 0);
}
int
tac_set_av(struct tac_handle *h, u_int index, const char *av)
{
if (index >= MAXAVPAIRS)
return -1;
return save_str(h, &(h->avs[index]), av, av != NULL ? strlen(av) : 0);
}
char *
tac_get_av(struct tac_handle *h, u_int index)
{
if (index >= MAXAVPAIRS)
return NULL;
return dup_str(h, &(h->srvr_avs[index]), NULL);
}
char *
tac_get_av_value(struct tac_handle *h, const char *attribute)
{
int i, len;
const char *ch, *end;
const char *candidate;
int candidate_len;
int found_seperator;
struct srvr_str srvr;
if (attribute == NULL || ((len = strlen(attribute)) == 0))
return NULL;
for (i=0; i<MAXAVPAIRS; i++) {
candidate = h->srvr_avs[i].data;
candidate_len = h->srvr_avs[i].len;
/*
* Valid 'srvr_avs' guaranteed to be contiguous starting at
* index 0 (not necessarily the case with 'avs'). Break out
* when the "end" of the list has been reached.
*/
if (!candidate)
break;
if (len < candidate_len &&
!strncmp(candidate, attribute, len)) {
ch = candidate + len;
end = candidate + candidate_len;
/*
* Sift out the white space between A and V (should not
* be any, but don't trust implementation of server...)
*/
found_seperator = 0;
while ((*ch == '=' || *ch == '*' || *ch == ' ' ||
*ch == '\t') && ch != end) {
if (*ch == '=' || *ch == '*')
found_seperator++;
ch++;
}
/*
* Note:
* The case of 'attribute' == "foo" and
* h->srvr_avs[0] = "foobie=var1"
* h->srvr_avs[1] = "foo=var2"
* is handled.
*/
if (found_seperator == 1 && ch != end) {
srvr.len = end - ch;
srvr.data = ch;
return dup_str(h, &srvr, NULL);
}
}
}
return NULL;
}
void
tac_clear_avs(struct tac_handle *h)
{
int i;
for (i=0; i<MAXAVPAIRS; i++)
save_str(h, &(h->avs[i]), NULL, 0);
}
static void
clear_srvr_avs(struct tac_handle *h)
{
int i;
for (i=0; i<MAXAVPAIRS; i++)
init_srvr_str(&(h->srvr_avs[i]));
}
const char *
tac_strerror(struct tac_handle *h)
{
return h->errmsg;
}
static void *
xmalloc(struct tac_handle *h, size_t size)
{
void *r;
if ((r = malloc(size)) == NULL)
generr(h, "Out of memory");
return r;
}
static char *
xstrdup(struct tac_handle *h, const char *s)
{
char *r;
if ((r = strdup(s)) == NULL)
generr(h, "Out of memory");
return r;
}