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freebsd-skq/lib/libtacplus/taclib.c
Pedro F. Giffuni 5e53a4f90f lib: further adoption of SPDX licensing ID tags. 
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-26 02:00:33 +00:00

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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("$FreeBSD$");
#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;
case TAC_ACCT:
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;
socklen_t errlen, peerlen;
int err;
/* 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;
}
int
tac_create_acct(struct tac_handle *h, int acct, int action, int type, int service)
{
struct tac_acct_start *as;
create_msg(h, TAC_ACCT, action, type);
as = &h->request.u.acct_start;
as->action = acct;
as->authen_action = action;
as->priv_lvl = TAC_PRIV_LVL_USER;
as->authen_type = type;
as->authen_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_send_acct(struct tac_handle *h)
{
register int i, current;
struct tac_acct_start *as = &h->request.u.acct_start;
struct tac_acct_reply *ar = &h->response.u.acct_reply;
/* start */
as = &h->request.u.acct_start;
h->request.length = htonl(offsetof(struct tac_acct_start, rest[0]));
for (as->av_cnt = 0, i = 0; i < MAXAVPAIRS; i++)
if (h->avs[i].len && h->avs[i].data)
as->av_cnt++;
h->request.length = ntohl(htonl(h->request.length) + as->av_cnt);
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)
return -1;
for (i = current = 0; i < MAXAVPAIRS; i++)
if (h->avs[i].len && h->avs[i].data)
if (add_str_8(h, &as->rest[current++], &(h->avs[i])) == -1)
return -1;
/* send */
if (send_msg(h) == -1 || recv_msg(h) == -1)
return -1;
/* reply */
h->srvr_pos = offsetof(struct tac_acct_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;
/* Sanity checks */
if (!h->single_connect)
close_connection(h);
return ar->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.
*
* Note that for empty string attribute values a
* 0-length string is returned in order to distinguish
* against unset values.
* dup_str() will handle srvr.len == 0 correctly.
*/
if (found_seperator == 1) {
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;
}
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