OpenBSD-4.6/kerberosV/src/lib/krb5/changepw.c
/*
* Copyright (c) 1997 - 2005 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* 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.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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 <krb5_locl.h>
RCSID("$KTH: changepw.c,v 1.53 2005/05/25 05:30:42 lha Exp $");
static void
str2data (krb5_data *d,
const char *fmt,
...) __attribute__ ((format (printf, 2, 3)));
static void
str2data (krb5_data *d,
const char *fmt,
...)
{
va_list args;
va_start(args, fmt);
d->length = vasprintf ((char **)&d->data, fmt, args);
va_end(args);
}
/*
* Change password protocol defined by
* draft-ietf-cat-kerb-chg-password-02.txt
*
* Share the response part of the protocol with MS set password
* (RFC3244)
*/
static krb5_error_code
chgpw_send_request (krb5_context context,
krb5_auth_context *auth_context,
krb5_creds *creds,
krb5_principal targprinc,
int is_stream,
int sock,
char *passwd,
const char *host)
{
krb5_error_code ret;
krb5_data ap_req_data;
krb5_data krb_priv_data;
krb5_data passwd_data;
size_t len;
u_char header[6];
u_char *p;
struct iovec iov[3];
struct msghdr msghdr;
if (is_stream)
return KRB5_KPASSWD_MALFORMED;
if (targprinc &&
krb5_principal_compare(context, creds->client, targprinc) != TRUE)
return KRB5_KPASSWD_MALFORMED;
krb5_data_zero (&ap_req_data);
ret = krb5_mk_req_extended (context,
auth_context,
AP_OPTS_MUTUAL_REQUIRED | AP_OPTS_USE_SUBKEY,
NULL, /* in_data */
creds,
&ap_req_data);
if (ret)
return ret;
passwd_data.data = passwd;
passwd_data.length = strlen(passwd);
krb5_data_zero (&krb_priv_data);
ret = krb5_mk_priv (context,
*auth_context,
&passwd_data,
&krb_priv_data,
NULL);
if (ret)
goto out2;
len = 6 + ap_req_data.length + krb_priv_data.length;
p = header;
*p++ = (len >> 8) & 0xFF;
*p++ = (len >> 0) & 0xFF;
*p++ = 0;
*p++ = 1;
*p++ = (ap_req_data.length >> 8) & 0xFF;
*p++ = (ap_req_data.length >> 0) & 0xFF;
memset(&msghdr, 0, sizeof(msghdr));
msghdr.msg_name = NULL;
msghdr.msg_namelen = 0;
msghdr.msg_iov = iov;
msghdr.msg_iovlen = sizeof(iov)/sizeof(*iov);
#if 0
msghdr.msg_control = NULL;
msghdr.msg_controllen = 0;
#endif
iov[0].iov_base = (void*)header;
iov[0].iov_len = 6;
iov[1].iov_base = ap_req_data.data;
iov[1].iov_len = ap_req_data.length;
iov[2].iov_base = krb_priv_data.data;
iov[2].iov_len = krb_priv_data.length;
if (sendmsg (sock, &msghdr, 0) < 0) {
ret = errno;
krb5_set_error_string(context, "sendmsg %s: %s", host, strerror(ret));
}
krb5_data_free (&krb_priv_data);
out2:
krb5_data_free (&ap_req_data);
return ret;
}
/*
* Set password protocol as defined by RFC3244 --
* Microsoft Windows 2000 Kerberos Change Password and Set Password Protocols
*/
static krb5_error_code
setpw_send_request (krb5_context context,
krb5_auth_context *auth_context,
krb5_creds *creds,
krb5_principal targprinc,
int is_stream,
int sock,
char *passwd,
const char *host)
{
krb5_error_code ret;
krb5_data ap_req_data;
krb5_data krb_priv_data;
krb5_data pwd_data;
ChangePasswdDataMS chpw;
size_t len;
u_char header[4 + 6];
u_char *p;
struct iovec iov[3];
struct msghdr msghdr;
krb5_data_zero (&ap_req_data);
ret = krb5_mk_req_extended (context,
auth_context,
AP_OPTS_MUTUAL_REQUIRED | AP_OPTS_USE_SUBKEY,
NULL, /* in_data */
creds,
&ap_req_data);
if (ret)
return ret;
chpw.newpasswd.length = strlen(passwd);
chpw.newpasswd.data = passwd;
if (targprinc) {
chpw.targname = &targprinc->name;
chpw.targrealm = &targprinc->realm;
} else {
chpw.targname = NULL;
chpw.targrealm = NULL;
}
ASN1_MALLOC_ENCODE(ChangePasswdDataMS, pwd_data.data, pwd_data.length,
&chpw, &len, ret);
if (ret) {
krb5_data_free (&ap_req_data);
return ret;
}
if(pwd_data.length != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
ret = krb5_mk_priv (context,
*auth_context,
&pwd_data,
&krb_priv_data,
NULL);
if (ret)
goto out2;
len = 6 + ap_req_data.length + krb_priv_data.length;
p = header;
if (is_stream) {
_krb5_put_int(p, len, 4);
p += 4;
}
*p++ = (len >> 8) & 0xFF;
*p++ = (len >> 0) & 0xFF;
*p++ = 0xff;
*p++ = 0x80;
*p++ = (ap_req_data.length >> 8) & 0xFF;
*p++ = (ap_req_data.length >> 0) & 0xFF;
memset(&msghdr, 0, sizeof(msghdr));
msghdr.msg_name = NULL;
msghdr.msg_namelen = 0;
msghdr.msg_iov = iov;
msghdr.msg_iovlen = sizeof(iov)/sizeof(*iov);
#if 0
msghdr.msg_control = NULL;
msghdr.msg_controllen = 0;
#endif
iov[0].iov_base = (void*)header;
if (is_stream)
iov[0].iov_len = 10;
else
iov[0].iov_len = 6;
iov[1].iov_base = ap_req_data.data;
iov[1].iov_len = ap_req_data.length;
iov[2].iov_base = krb_priv_data.data;
iov[2].iov_len = krb_priv_data.length;
if (sendmsg (sock, &msghdr, 0) < 0) {
ret = errno;
krb5_set_error_string(context, "sendmsg %s: %s", host, strerror(ret));
}
krb5_data_free (&krb_priv_data);
out2:
krb5_data_free (&ap_req_data);
krb5_data_free (&pwd_data);
return ret;
}
static krb5_error_code
process_reply (krb5_context context,
krb5_auth_context auth_context,
int is_stream,
int sock,
int *result_code,
krb5_data *result_code_string,
krb5_data *result_string,
const char *host)
{
krb5_error_code ret;
u_char reply[1024 * 3];
ssize_t len;
u_int16_t pkt_len, pkt_ver;
krb5_data ap_rep_data;
int save_errno;
len = 0;
if (is_stream) {
while (len < sizeof(reply)) {
unsigned long size;
ret = recvfrom (sock, reply + len, sizeof(reply) - len,
0, NULL, NULL);
if (ret < 0) {
save_errno = errno;
krb5_set_error_string(context, "recvfrom %s: %s",
host, strerror(save_errno));
return save_errno;
} else if (ret == 0) {
krb5_set_error_string(context, "recvfrom timeout %s", host);
return 1;
}
len += ret;
if (len < 4)
continue;
_krb5_get_int(reply, &size, 4);
if (size + 4 < len)
continue;
memmove(reply, reply + 4, size);
len = size;
break;
}
if (len == sizeof(reply)) {
krb5_set_error_string(context, "message too large from %s",
host);
return ENOMEM;
}
} else {
ret = recvfrom (sock, reply, sizeof(reply), 0, NULL, NULL);
if (ret < 0) {
save_errno = errno;
krb5_set_error_string(context, "recvfrom %s: %s",
host, strerror(save_errno));
return save_errno;
}
len = ret;
}
if (len < 6) {
str2data (result_string, "server %s sent to too short message "
"(%ld bytes)", host, (long)len);
*result_code = KRB5_KPASSWD_MALFORMED;
return 0;
}
pkt_len = (reply[0] << 8) | (reply[1]);
pkt_ver = (reply[2] << 8) | (reply[3]);
if ((pkt_len != len) || (reply[1] == 0x7e || reply[1] == 0x5e)) {
KRB_ERROR error;
size_t size;
u_char *p;
memset(&error, 0, sizeof(error));
ret = decode_KRB_ERROR(reply, len, &error, &size);
if (ret)
return ret;
if (error.e_data->length < 2) {
str2data(result_string, "server %s sent too short "
"e_data to print anything usable", host);
free_KRB_ERROR(&error);
*result_code = KRB5_KPASSWD_MALFORMED;
return 0;
}
p = error.e_data->data;
*result_code = (p[0] << 8) | p[1];
if (error.e_data->length == 2)
str2data(result_string, "server only sent error code");
else
krb5_data_copy (result_string,
p + 2,
error.e_data->length - 2);
free_KRB_ERROR(&error);
return 0;
}
if (pkt_len != len) {
str2data (result_string, "client: wrong len in reply");
*result_code = KRB5_KPASSWD_MALFORMED;
return 0;
}
if (pkt_ver != KRB5_KPASSWD_VERS_CHANGEPW) {
str2data (result_string,
"client: wrong version number (%d)", pkt_ver);
*result_code = KRB5_KPASSWD_MALFORMED;
return 0;
}
ap_rep_data.data = reply + 6;
ap_rep_data.length = (reply[4] << 8) | (reply[5]);
if (reply + len < (u_char *)ap_rep_data.data + ap_rep_data.length) {
str2data (result_string, "client: wrong AP len in reply");
*result_code = KRB5_KPASSWD_MALFORMED;
return 0;
}
if (ap_rep_data.length) {
krb5_ap_rep_enc_part *ap_rep;
krb5_data priv_data;
u_char *p;
priv_data.data = (u_char*)ap_rep_data.data + ap_rep_data.length;
priv_data.length = len - ap_rep_data.length - 6;
ret = krb5_rd_rep (context,
auth_context,
&ap_rep_data,
&ap_rep);
if (ret)
return ret;
krb5_free_ap_rep_enc_part (context, ap_rep);
ret = krb5_rd_priv (context,
auth_context,
&priv_data,
result_code_string,
NULL);
if (ret) {
krb5_data_free (result_code_string);
return ret;
}
if (result_code_string->length < 2) {
*result_code = KRB5_KPASSWD_MALFORMED;
str2data (result_string,
"client: bad length in result");
return 0;
}
p = result_code_string->data;
*result_code = (p[0] << 8) | p[1];
krb5_data_copy (result_string,
(unsigned char*)result_code_string->data + 2,
result_code_string->length - 2);
return 0;
} else {
KRB_ERROR error;
size_t size;
u_char *p;
ret = decode_KRB_ERROR(reply + 6, len - 6, &error, &size);
if (ret) {
return ret;
}
if (error.e_data->length < 2) {
krb5_warnx (context, "too short e_data to print anything usable");
return 1; /* XXX */
}
p = error.e_data->data;
*result_code = (p[0] << 8) | p[1];
krb5_data_copy (result_string,
p + 2,
error.e_data->length - 2);
return 0;
}
}
/*
* change the password using the credentials in `creds' (for the
* principal indicated in them) to `newpw', storing the result of
* the operation in `result_*' and an error code or 0.
*/
typedef krb5_error_code (*kpwd_send_request) (krb5_context,
krb5_auth_context *,
krb5_creds *,
krb5_principal,
int,
int,
char *,
const char *);
typedef krb5_error_code (*kpwd_process_reply) (krb5_context,
krb5_auth_context,
int,
int,
int *,
krb5_data *,
krb5_data *,
const char *);
static struct kpwd_proc {
const char *name;
int flags;
#define SUPPORT_TCP 1
#define SUPPORT_UDP 2
kpwd_send_request send_req;
kpwd_process_reply process_rep;
} procs[] = {
{
"MS set password",
SUPPORT_TCP|SUPPORT_UDP,
setpw_send_request,
process_reply
},
{
"change password",
SUPPORT_UDP,
chgpw_send_request,
process_reply
},
{ NULL }
};
static struct kpwd_proc *
find_chpw_proto(const char *name)
{
struct kpwd_proc *p;
for (p = procs; p->name != NULL; p++) {
if (strcmp(p->name, name) == 0)
return p;
}
return NULL;
}
/*
*
*/
static krb5_error_code
change_password_loop (krb5_context context,
krb5_creds *creds,
krb5_principal targprinc,
char *newpw,
int *result_code,
krb5_data *result_code_string,
krb5_data *result_string,
struct kpwd_proc *proc)
{
krb5_error_code ret;
krb5_auth_context auth_context = NULL;
krb5_krbhst_handle handle = NULL;
krb5_krbhst_info *hi;
int sock;
int i;
int done = 0;
krb5_realm realm = creds->client->realm;
ret = krb5_auth_con_init (context, &auth_context);
if (ret)
return ret;
krb5_auth_con_setflags (context, auth_context,
KRB5_AUTH_CONTEXT_DO_SEQUENCE);
ret = krb5_krbhst_init (context, realm, KRB5_KRBHST_CHANGEPW, &handle);
if (ret)
goto out;
while (!done && (ret = krb5_krbhst_next(context, handle, &hi)) == 0) {
struct addrinfo *ai, *a;
int is_stream;
switch (hi->proto) {
case KRB5_KRBHST_UDP:
if ((proc->flags & SUPPORT_UDP) == 0)
continue;
is_stream = 0;
break;
case KRB5_KRBHST_TCP:
if ((proc->flags & SUPPORT_TCP) == 0)
continue;
is_stream = 1;
break;
default:
continue;
}
ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
if (ret)
continue;
for (a = ai; !done && a != NULL; a = a->ai_next) {
int replied = 0;
sock = socket (a->ai_family, a->ai_socktype, a->ai_protocol);
if (sock < 0)
continue;
ret = connect(sock, a->ai_addr, a->ai_addrlen);
if (ret < 0) {
close (sock);
goto out;
}
ret = krb5_auth_con_genaddrs (context, auth_context, sock,
KRB5_AUTH_CONTEXT_GENERATE_LOCAL_ADDR);
if (ret) {
close (sock);
goto out;
}
for (i = 0; !done && i < 5; ++i) {
fd_set fdset;
struct timeval tv;
if (!replied) {
replied = 0;
ret = (*proc->send_req) (context,
&auth_context,
creds,
targprinc,
is_stream,
sock,
newpw,
hi->hostname);
if (ret) {
close(sock);
goto out;
}
}
if (sock >= FD_SETSIZE) {
krb5_set_error_string(context, "fd %d too large", sock);
ret = ERANGE;
close (sock);
goto out;
}
FD_ZERO(&fdset);
FD_SET(sock, &fdset);
tv.tv_usec = 0;
tv.tv_sec = 1 + (1 << i);
ret = select (sock + 1, &fdset, NULL, NULL, &tv);
if (ret < 0 && errno != EINTR) {
close(sock);
goto out;
}
if (ret == 1) {
ret = (*proc->process_rep) (context,
auth_context,
is_stream,
sock,
result_code,
result_code_string,
result_string,
hi->hostname);
if (ret == 0)
done = 1;
else if (i > 0 && ret == KRB5KRB_AP_ERR_MUT_FAIL)
replied = 1;
} else {
ret = KRB5_KDC_UNREACH;
}
}
close (sock);
}
}
out:
krb5_krbhst_free (context, handle);
krb5_auth_con_free (context, auth_context);
if (done)
return 0;
else {
if (ret == KRB5_KDC_UNREACH) {
krb5_set_error_string(context,
"unable to reach any changepw server "
" in realm %s", realm);
*result_code = KRB5_KPASSWD_HARDERROR;
}
return ret;
}
}
/*
* change the password using the credentials in `creds' (for the
* principal indicated in them) to `newpw', storing the result of
* the operation in `result_*' and an error code or 0.
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_change_password (krb5_context context,
krb5_creds *creds,
char *newpw,
int *result_code,
krb5_data *result_code_string,
krb5_data *result_string)
{
struct kpwd_proc *p = find_chpw_proto("change password");
*result_code = KRB5_KPASSWD_MALFORMED;
result_code_string->data = result_string->data = NULL;
result_code_string->length = result_string->length = 0;
if (p == NULL)
return KRB5_KPASSWD_MALFORMED;
return change_password_loop(context, creds, NULL, newpw,
result_code, result_code_string,
result_string, p);
}
/*
*
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_set_password(krb5_context context,
krb5_creds *creds,
char *newpw,
krb5_principal targprinc,
int *result_code,
krb5_data *result_code_string,
krb5_data *result_string)
{
krb5_principal principal = NULL;
krb5_error_code ret = 0;
int i;
*result_code = KRB5_KPASSWD_MALFORMED;
result_code_string->data = result_string->data = NULL;
result_code_string->length = result_string->length = 0;
if (targprinc == NULL) {
ret = krb5_get_default_principal(context, &principal);
if (ret)
return ret;
} else
principal = targprinc;
for (i = 0; procs[i].name != NULL; i++) {
*result_code = 0;
ret = change_password_loop(context, creds, targprinc, newpw,
result_code, result_code_string,
result_string,
&procs[i]);
if (ret == 0 && *result_code == 0)
break;
}
if (targprinc == NULL)
krb5_free_principal(context, principal);
return ret;
}
/*
*
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_set_password_using_ccache(krb5_context context,
krb5_ccache ccache,
char *newpw,
krb5_principal targprinc,
int *result_code,
krb5_data *result_code_string,
krb5_data *result_string)
{
krb5_creds creds, *credsp;
krb5_error_code ret;
krb5_principal principal = NULL;
*result_code = KRB5_KPASSWD_MALFORMED;
result_code_string->data = result_string->data = NULL;
result_code_string->length = result_string->length = 0;
memset(&creds, 0, sizeof(creds));
if (targprinc == NULL) {
ret = krb5_cc_get_principal(context, ccache, &principal);
if (ret)
return ret;
} else
principal = targprinc;
ret = krb5_make_principal(context, &creds.server,
krb5_principal_get_realm(context, principal),
"kadmin", "changepw", NULL);
if (ret)
goto out;
ret = krb5_cc_get_principal(context, ccache, &creds.client);
if (ret) {
krb5_free_principal(context, creds.server);
goto out;
}
ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp);
krb5_free_principal(context, creds.server);
krb5_free_principal(context, creds.client);
if (ret)
goto out;
ret = krb5_set_password(context,
credsp,
newpw,
principal,
result_code,
result_code_string,
result_string);
krb5_free_creds(context, credsp);
return ret;
out:
if (targprinc == NULL)
krb5_free_principal(context, principal);
return ret;
}
/*
*
*/
const char* KRB5_LIB_FUNCTION
krb5_passwd_result_to_string (krb5_context context,
int result)
{
static const char *strings[] = {
"Success",
"Malformed",
"Hard error",
"Auth error",
"Soft error" ,
"Access denied",
"Bad version",
"Initial flag needed"
};
if (result < 0 || result > KRB5_KPASSWD_INITIAL_FLAG_NEEDED)
return "unknown result code";
else
return strings[result];
}